identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
03AE4066FFB6D45C1772FC84FEEAFE43.text	03AE4066FFB6D45C1772FC84FEEAFE43.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Condyloderes notios Sørensen & Macheriotou & Braeckman & Smith & Ingels 2025	<div><p>Condyloderes notios sp. nov urn:lsid:zoobank.org:act: 3F5ACC7E-5173-4871-8465-642D9E7F473C</p><p>Figs 2–4, Tables 5–6</p><p>Diagnosis</p><p>Condyloderes with acicular spines in middorsal positions on segments 1 to 10, and in lateroventral positions on segments 1 to 9; laterodorsal acicular spines present on segment 10, at least in males. Unpaired cuspidate spines present in paradorsal position on segments 1, 5, and 7. Paired cuspidate spines present in lateral accessory positions on segment 1, in ventrolateral positions on segment 5, in lateroventral positions on segment 8, and in ventrolateral positions on segment 9. Female morphology unknown.</p><p>Etymology</p><p>The species name notios is from the Greek νότιος = ‘southern’, with reference to the species being the southernmost representative of Condyloderes and only the second member of the genus recorded from the Southern Hemisphere.</p><p>Material examined</p><p>Holotype ANTARCTICA • ♂ (mounted for LM in Fluoromount G on HS slide); Antarctic Peninsula, CRS 1702; 64°51.15′ S, 62°34.44′ W; 502 m b.s.l.; 30 Nov. 2015; FjordEco 1; soft sediment; NHMD 1784659.</p><p>Additional material</p><p>ANTARCTICA – Antarctic Peninsula • 1 juv. (mounted for LM in Fluoromount G on HS slide); CRS 1706; 64°50.47′ S, 62°35.12′ W; 499 m b.s.l.; 1 Dec. 2015; FjordEco1; soft sediment; NHMD 1784660 • 1 juv. (mounted for SEM); CRS 1793; 64°39.53′ S, 62°55.03′ W; 701 m b.s.l.; 11 Apr. 2016; FjordEco2; soft sediment; MVS • 3 ♂♂, 2 juv. (mounted for SEM); CRS 1832; 64°39.30′ S, 62°55.98′ W; 631 m b.s.l.; 21 Apr. 2016; FjordEco2; soft sediment; MVS .</p><p>Description</p><p>GENERAL. Adults with head, neck and eleven trunk segments (Figs 2, 3A, 4A–D). An overview of measurements and dimensions is given in Table 5. Distributions of cuticular structures, i.e., sensory spots and spines, are summarized in Table 6. Only males and juveniles were available for examination, so female dimorphism remains unknown for this species.</p><p>HEAD. Consists of a retractable mouth cone and an introvert (Fig. 4C). Only one specimen had its head partially protruded and thus information on head morphology is limited. Outer oral styles are composed of two units, with the proximal unit being considerably thicker than the distal.</p><p>INTROVERT. Primary spinoscalids are composed of a single unit, with a basal, transverse fringe and a row of fine hairs extending about ¼ down along the proximal part of the scalid; the distal ¾ are smooth, with a few transverse, partial wrinkles, giving the distal part a finger-like appearance. Remaining scalids appear to be located in introvert rings 2 to 5; they are composed of a basal sheath with a median fringe and a pointed end-piece. Scalids of Ring 4 (located centrally in each introvert sector) are flanked by a pair of thin, thread-like appendages, covered with minute hairs; the hair-covering makes them resemble thin trichoscalids. Trichoscalids are well-developed and located in the posteriormost ring.</p><p>NECK. Consists of 16 placids with condyles (Fig. 4D). All placids are about 12 µm in length, but differ in width. The midventral placid is the broadest, 15 µm wide. It is flanked by two pairs of narrow placids, each measuring 7 µm in width. From the two pairs of narrow, ventromedial placids, the placids alternate between broad (width: 13 µm) and narrow (width: 7 µm) ones towards the narrow middorsal placid. All condyles form structures with a narrow posterior part that broadens anteriorly, which makes them resemble small mushrooms. The midventral placid has three condyles, whereas other broad placids have two condyles, and narrow ones have a single.</p><p>SEGMENT 1. Consists of a complete cuticular ring. Acicular spines are present in middorsal and lateroventral positions, and cuspidate spines are present as an unpaired paradorsal spine and as paired lateral accessory spines; direction (left or right) of lateral shift in position of the unpaired paradorsal cuspidate spine differs between specimens. Sensory spots are present as two pair in subdorsal positions, two pairs in laterodorsal positions, and one pair in ventromedial positions. Sensory spots on this and following eight segments are slightly protruding and composed of numerous micropapillae around a central pore, i.e., corresponding to sensory spot type 6 sensu Neuhaus et al. (2019). The surface of the tergal plate is reticulated at its anterior half and has a narrow zone with minute triangular hairs, in between the reticulated part and the relatively broad free flap; sternal plate surfaces are reticulated throughout, from anterior margin to posterior free flaps; dense coverings of thin cuticular hairs are present in areas anterior to the middorsal and lateroventral acicular spines. The free flaps, marking the posterior segment margins, have longitudinal lines that extend beyond the margins of the free flaps and form minute, pointed tips. The posterior margin is mostly straight, with notches at the attachment sites of the lateroventral spines, and with a small and rather narrow midventral indentation, only expanding over the paraventral areas (Figs 2A–B, 3B–C, 4D–G).</p><p>SEGMENT 2. As the following eight segments, consists of a tergal and two sternal plates. Acicular spines are present in middorsal and lateroventral positions. Sensory spots are present in paradorsal, subdorsal, laterodorsal (two pairs), and ventromedial positions. Tergal plate and lateral halves of sternal plates are covered with minute, triangular hairs; ventralmost halves of sternal plates with reticulated surfaces. Free flaps as on preceding segment and posterior segment margin mostly straight, but with notches at the attachment sites of the lateroventral spines (Figs 2A–B, 3B–C, 4E–G).</p><p>SEGMENT 3. As preceding segment, but only with one pair of laterodorsal sensory spots (Figs 2A–B, 3B–C, 4E).</p><p>SEGMENT 4. As preceding segment, but without laterodorsal sensory spots. Subdorsal sensory spots usually present, but were missing in one specimen (Figs 2A–B, 3B–C, 4E, H).</p><p>SEGMENT 5. With acicular spines in middorsal and lateroventral positions, and cuspidate spines present as an unpaired paradorsal spine and as paired ventrolateral spines; direction of lateral shift in position of the unpaired paradorsal cuspidate spine differs between specimens and irrespective of position of paradorsal cuspidate spine on segment 1. Sensory spots present in paradorsal, subdorsal, laterodorsal, and ventromedial positions. Cuticular ornamentation, free flap, and posterior segment margin as on preceding segment (Figs 2A–B, 3B–C, 4H–J).</p><p>SEGMENT 6. With same arrangement of cuticular structures as on segment 3 (Figs 2A–B, 3B–E, 4H–J).</p><p>SEGMENT 7. With acicular spines in middorsal and lateroventral positions, and an unpaired, cuspidate spine in paradorsal position; direction of lateral shift in position of the unpaired paradorsal cuspidate spine differs between specimens and irrespective of position of paradorsal cuspidate spines on preceding segments. Sensory spots present in paradorsal, subdorsal, laterodorsal, and ventromedial positions. Cuticular ornamentation, free flap, and posterior segment margin as on preceding segment (Figs 2A–B, 3D–E, 4K–M).</p><p>SEGMENT 8. With acicular spines in middorsal and lateroventral positions, and cuspidate spines also in lateroventral positions, attaching posterior to acicular spines. Sensory spots present in paradorsal, subdorsal, laterodorsal, and ventromedial positions. Cuticular ornamentation, free flap, and posterior segment margin as on preceding segment (Figs 2A–B, 3D–E, G–H, 4L–M).</p><p>SEGMENT 9. With acicular spines in middorsal and lateroventral positions, and cuspidate spines in ventrolateral positions. Sensory spots present in paradorsal, laterodorsal, and ventromedial positions. A pair of minute nephridiopores, appearing as a tuft of short micropapillae, is located next to, but more dorsal than, the laterodorsal sensory spots (Fig. 4O). Cuticular ornamentation, free flap, and posterior segment margin as on preceding segment (Figs 2A–B, 3D–H, 4N–P).</p><p>SEGMENT 10. With acicular spines in middorsal and laterodorsal positions. Sensory spots type 3, i.e., stalked sensory spots, present in subdorsal positions (but missing in one specimen); sensory spots type 6 present in lateroventral positions, at the posterior segment margin. Cuticular ornamentation, free flap, and posterior segment margin otherwise as on preceding segment (Figs 2A–B, 3D–H, 4N–P).</p><p>SEGMENT 11. Consists of a tergal and a sternal plate. Lateral terminal accessory spines and midterminal spine are present; lateral terminal accessory spines are about 70% longer than the midterminal. Stalked sensory spots type 3 are present in subdorsal and ventrolateral positions, and sensory spots type 6 in ventromedial positions. The tergal plate is covered with minute, triangular hairs, whereas the sternal plate is mostly smooth and ornamented with fine, longitudinal lines. A free flap with irregular longitudinal lines is present at the tergal plate only; the sternal plate terminates in a finely serrated edge (Figs 2A–B, 3G–H, 4N–P).</p><p>Distribution</p><p>Antarctic Peninsula: Gerlache Strait and Andvord Bay MBA, 499 to 701 m. See Fig. 1 for geographic overview of stations and Table 1 for station and specimen information.</p><p>Diagnostic remarks</p><p>The placids with condyles, and the segment composition, with segment 1 composed of a closed cuticular ring, segments 2 to 10 composed of one tergal and two sternal plates, and segment 11 of one tergal and one sternal plate, easily assigns the new species to Condyloderes . The genus currently accommodates eleven species, including Condyloderes notios sp. now.</p><p>The new species is most easily distinguished from its congeners by its unique cuspidate spine pattern. The presence of cuspidate spines in mid- or paradorsal positions is only shared with three other species, i.e., Condyloderes agnetis Dal Zotto et al., 2019, C. shirleyi Neuhaus et al., 2019, and C. storchi Higgins in Martorelli &amp; Higgins, 2004. However, none of the three species have paradorsal cuspidate spines on segment 1, which in itself makes C. notios sp. nov. differ from all other congeners. Of the three species, the Mediterranean C. agnetis differs the most, by having paired paradorsal cuspidate spines on segments 3 and 7 (Dal Zotto et al. 2019), opposite to the unpaired ones on segments 1, 5, and 7 in C. notios . In both species the cuspidate spines are reported as paradorsal, but in C. agnetis the cuspidate spines are clearly more laterally displaced, and thus very close to being subdorsal. In contrast, the unpaired paradorsal cuspidate spines in C. notios are so close to the middorsal line that they almost could be interpreted as middorsal.</p><p>Condyloderes shirleyi and C. storchi show more similarity to the new species, as they both have unpaired middorsal or paradorsal cuspidate spines on segments 5 and 7, but besides lacking a paradorsal cuspidate spine on segment 1, their cuspidate spine pattern in the lateral series also differs considerably. Condyloderes shirleyi differs by having cuspidate spines in the lateral series of segments 2, 6, and 7, but not on segment 1 (Neuhaus et al. 2019), and C. shirleyi by having lateral accessory cuspidate spines on segment 4 (Martorelli &amp; Higgins 2004; Neuhaus et al. 2019).</p><p>If compared with the remaining Condyloderes species without cuspidate spines in the dorsal series, C. notios sp. nov. shows most resemblance with C. clarae Dal Zotto et al., 2019 and C. flosfimbriatus Sørensen et al., 2019, as they also have cuspidate spines in the lateral or ventral series of segments 5, 8 and 9, but none of them have lateral accessory cuspidate spines on segment 1 (Dal Zotto et al. 2019; Sørensen et al. 2019). Among its ten congeners, C. notios clearly shows greatest resemblance with C. storchi, which also happens to be the only other species of Condyloderes described from the southern hemisphere.</p></div>	https://treatment.plazi.org/id/03AE4066FFB6D45C1772FC84FEEAFE43	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Sørensen, Martin V.;Macheriotou, Lara;Braeckman, Ulrike;Smith, Craig R.;Ingels, Jeroen	Sørensen, Martin V., Macheriotou, Lara, Braeckman, Ulrike, Smith, Craig R., Ingels, Jeroen (2025): Antarctic Kinorhyncha: Seven new species from the Antarctic Peninsula. European Journal of Taxonomy 1000 (1): 1-102, DOI: 10.5852/ejt.2025.1000.2947, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2947/13307
03AE4066FFAED453174AFDB9FCD7FE20.text	03AE4066FFAED453174AFDB9FCD7FE20.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Polacanthoderes grzelakae Sørensen & Macheriotou & Braeckman & Smith & Ingels 2025	<div><p>Polacanthoderes grzelakae sp. nov urn:lsid:zoobank.org:act: 3966DEF9-01C9-4294-AAFB-DCDB56648067</p><p>Figs 5–8, Tables 7–8</p><p>Diagnosis</p><p>Polacanthoderes with regular acicular spines in middorsal positions on segments 4 to 8, and in lateroventral positions on segments 6 to 9; lateroventral spines on segments 8 (in particular) and 9 are conspicuously stronger than other acicular spines, and the one on segment 8 is the strongest. Tubes are present in subdorsal and ventrolateral positions on segment 2, midlateral positions on segment 4, lateroventral positions on segment 5, and laterodorsal positions on segment 10. Small acicular spines are present in the following series: subdorsal positions on segments 4 and 5 (but missing in some specimens), laterodorsal positions on segments 6 to 8, midlateral positions on segments 5 to 9, sublateral positions on segment 7, lateral accessory positions on segments 6 and 8 to 9, ventrolateral positions on segments 8 to 10, and in ventromedial positions on segments 4 to 7. Glandular cell outlets type 2 are present in midlateral positions on segments 6 and 8. Dorsal glandular cell outlets type 1 are present in middorsal positions on segments 1 to 3 and 10, and in paradorsal positions on segments 4 to 9. Small sieve plates present on segment 9 in sublateral positions.</p><p>Etymology</p><p>The species is dedicated to Katarzyna Grzelak – a fabulous kinorhynch taxonomist and meiofauna ecologist.</p><p>Material examined</p><p>Holotype ANTARCTICA • ♂ (mounted for LM in Fluoromount G on HS slide); Antarctic Peninsula, CRS 1706; 64°50.47′ S, 62°35.12′ W; 499 m b.s.l.; 1 Dec. 2015; FjordEco1; soft sediment; NHMD 1784249.</p><p>Paratypes</p><p>ANTARCTICA – Antarctic Peninsula • 1♀ (mounted as holotype); CRS 1769; 64°52.37′ S, 62°25.27′ W; 547 m b.s.l.; 5 Apr. 2016; FjordEco2; soft sediment; USNM 1740027 • 1 ♂ (mounted as holotype); CRS 1773; 64°52.35′ S, 62°25.88′ W; 553 m b.s.l.; 6 Apr. 2016; FjordEco2; soft sediment; NHMD 1784250 • 1 ♂ (mounted as holotype); CRS 1776; 64°52.53′ S, 62°33.90′ W; 551 m b.s.l.; 7 Apr. 2016; FjordEco2; soft sediment; USNM 1740028 • 3 ♀♀ (mounted as holotype); CRS 1793; 64°39.53′ S, 62°55.03′ W; 701 m b.s.l.; 11 Apr. 2016; FjordEco2; soft sediment; NHMD 1784251, 1784284, 1784303 • 2 ♂♂, 1 ♀ (mounted as holotype); CRS 1809; 64°39.59′ S, 62°55.09′ W; 694 m b.s.l.; 15 Apr. 2016; FjordEco2; soft sediment; NHMD 1784304 to 1784306 .</p><p>Additional material</p><p>ANTARCTICA – Antarctic Peninsula • 1 ♀ (mounted for SEM); same data as for holotype; MVS • 1 ♂ (mounted for SEM); CRS 1776; 64°52.53′ S, 62°33.90′ W; 551 m b.s.l.; 7 Apr. 2016; FjordEco2; soft sediment; MVS • 4 ♂♂, 1 ♀ (mounted for SEM); CRS 1793; 64°39.53′ S, 62°55.03′ W; 701 m b.s.l.; 11 Apr. 2016; FjordEco2; soft sediment; MVS • 3 ♂♂, 1 ♀ (mounted for SEM); CRS 1809; 64°39.59′ S, 62°55.09′ W; 694 m b.s.l.; 15 Apr. 2016; FjordEco2; soft sediment; MVS • 4 ♂♂, 5 ♀♀ (mounted for SEM); CRS 1832; 64°39.30′ S, 62°55.98′ W; 631 m b.s.l.; 21 Apr. 2016; FjordEco2; soft sediment; MVS .</p><p>Description</p><p>GENERAL. Adults with head, neck and eleven trunk segments (Figs 5A–B, 6, 7A, 8B). The species is large for an Echinoderidae, 467 to 488 µm in trunk length, and the segments are completely devoid of regular, cuticular hairs. An overview of measurements and dimensions is given in Table 7. Distributions of cuticular structures, i.e., sensory spots, glandular cell outlets, spines, and tubes, are summarized in Table 8.</p><p>HEAD. Consists of a retractable mouth cone and an introvert (Figs 6, 8A). Inner oral styles of mouth cone are arranged in three rings: 10 styles are present in the outermost ring and 5 in the following. The innermost ring could not be examined. The external mouth cone armature consists of nine outer oral styles; bases of outer oral styles each flanked by a transverse fringe row consisting of very short spikes and a V-shaped row with considerably longer tips.</p><p>INTROVERT. The sectors are defined by the ten primary spinoscalids in Ring 01. Each primary spinoscalid consists of a basal sheath and a distal end piece with a blunt tip. The sheaths have, described from proximal towards distal parts: a transverse fringe with ca 10 long fringe tips; a slightly more distal fringe with four, terminally bifurcated fringe tips; and numerous short fringe tips along the distal margin of the sheath. End pieces are flexible and smooth. Rings 02 and 04 have 10 spinoscalids, and Rings 03 and 05 have 20 spinoscalids. All spinoscalids in these rings are well-developed, and consist of a basal sheath and a pointed end piece. Ring 06 has only 6 spinoscalids, located in sectors 1, 3, 5, 6, 7, and 9; they resemble those in preceding sectors, but without the distinct differentiation into sheath and end piece. Ring 07 has 8 spinoscalids, located as pairs in sectors 1, 3, and 9, and unpaired but laterally displaced in sectors 5 and 7 (trichoscalids take up the space in the opposite side of each sector); ring 07 spinoscalids appear very simplified and resemble thin fringes rather than actual scalids (Figs 6, 8A). Described sector-wise (Fig. 6), sectors 1, 3, and 9 are similar, having spinoscalids arranged as two double diamonds anterior to an additional pair of Ring 07 spinoscalids. Sectors 2, 4, 8, and 10 all have spinoscalids arranged as a quincunx, located in between an anterior spinoscalid in Ring 02 and a trichoscalid plate. Sectors 5 and 7 have spinoscalids forming double diamonds, anterior to an unpaired, lateral spinoscalid; the lateral spinoscalid is unpaired because a trichoscalid plate takes up the space in the opposite side of the sector. Sector 6 has its trichoscalids arranged as double diamonds. Regular trichoscalids with trichoscalid plates are present in sectors 2, 4, 5, 7, 8, and 10.</p><p>NECK. Consists of 16 placids. Midventral placid broadest, 17 µm in width and 18 µm in length, whereas all others are narrower, measuring 9 µm in width at their bases (Fig. 7B–C). The trichoscalid plates are well-developed.</p><p>SEGMENT 1. Consists of a complete cuticular ring. Sensory spots are present in subdorsal, laterodorsal sublateral, and ventromedial positions; sensory spots on this and following segments are small, slightly depressed into the cuticle, rounded, and composed of a central pore surrounded by a few micropapillae. Glandular cell outlets type 1 are present in middorsal and ventromedial positions. Posterior segment margin with very fine denticles in middorsal to midlateral positions and hardly any denticles or fringe tips at all in sublateral to ventromedial positions; ventromedial to midventral positions though with 11 to 13 strongly developed, dagger-shaped fringe tips (Figs 5A–B, 7B–C, 8C–D).</p><p>SEGMENT 2. As remaining segments, consists of a tergal and two sternal plates. Tubes are present in subdorsal and ventrolateral positions. Sensory spots are present in middorsal position, as two pairs in laterodorsal positions and in ventromedial positions. Glandular cell outlets type 1 are present in middorsal position and ventromedial positions; ventromedial outlets are located close, but anterior to the ventromedial sensory spots. The posterior segment margin is straight, with small denticles along the tergal plate and slightly longer but also thinner fringe tips along the margins of the sternal plates (Figs 5A–B, 7B–C, 8C–D).</p><p>SEGMENT 3. With sensory spots present in subdorsal, laterodorsal, midlateral and ventromedial positions, and glandular cell outlets type 1 in middorsal and ventromedial positions. A single specimen had small acicular spines in ventromedial positions. Posterior segment margin as on preceding segment (Figs 5A–B, 7C, 8C–E).</p><p>SEGMENT 4. With regular, acicular spine in middorsal position and small acicular spines in subdorsal and ventromedial positions; small subdorsal acicular spines were missing in five specimens. Tubes present midlateral positions; tubes missing in one specimen. Sensory spots present in subdorsal and ventromedial positions; subdorsal sensory spots slightly more lateral than subdorsal acicular spines. Glandular cell outlets type 1 present in paradorsal and ventromedial positions. Posterior segment margin as on preceding segment (Figs 5A–B, 7B–C, 8D–F).</p><p>SEGMENT 5. With regular, acicular spine in middorsal position and small acicular spines in subdorsal, midlateral, and ventromedial positions; small subdorsal acicular spines were missing in five specimens. Tubes present lateroventral positions. Sensory spots present in subdorsal, midlateral, and ventromedial positions; subdorsal sensory spots slightly more lateral than subdorsal acicular spines, as on preceding segment. Glandular cell outlets type 1 present in paradorsal and ventromedial positions. Posterior segment margin as on preceding segment (Figs 5A–B, 7D–E, 8D–F).</p><p>SEGMENT 6. With regular, acicular spines in middorsal and lateroventral positions, and small acicular spines in laterodorsal, midlateral, lateral accessory, and ventromedial positions; one specimen had an extra set of laterodorsal small acicular spines, whereas another specimen lacked short lateral accessory acicular spines. Well-developed glandular cell outlets type 2, located in midlateral positions, slightly posterior to the short acicular spines. Females with ventromedial female papillae, forming small funnel-shaped intracuticular structures. Sensory spots present in paradorsal, laterodorsal and ventromedial positions; laterodorsal sensory spots slightly more dorsal than laterodorsal acicular spines. Glandular cell outlets type 1 present in paradorsal and ventromedial positions. Posterior segment margin as on preceding segment (Figs 5A–B, D, 7D–E, H, 8F, H–I).</p><p>SEGMENT 7. With regular, acicular spines in middorsal and lateroventral positions, and small acicular spines in laterodorsal, midlateral, sublateral and ventromedial positions; one specimen also with a pair of small acicular spines in lateral accessory positions. Females with ventrolateral female papillae, forming small funnel-shaped intracuticular structures. Sensory spots present in paradorsal, laterodorsal, midlateral, and ventromedial positions. Glandular cell outlets type 1 and posterior segment margin as on preceding segment (Figs 5A–B, D, 7F–H, 8F, H–I).</p><p>SEGMENT 8. With regular, acicular spines in middorsal and lateroventral positions, and small acicular spines in laterodorsal, midlateral, lateral accessory, and ventrolateral positions; lateroventral acicular spines are conspicuously strong on this segment and nearly twice as thick as the lateroventral spines on the two preceding segments; small laterodorsal acicular spines were missing in two specimens. Well-developed glandular cell outlets type 2, located in midlateral positions, slightly posterior to the short acicular spines. Sensory spots present in paradorsal, laterodorsal, and ventrolateral positions. Glandular cell outlets type 1 and posterior segment margin as on preceding segment (Figs 5A–B, 7F–G, J, 8G, I).</p><p>SEGMENT 9. With regular, acicular spines in lateroventral positions and small acicular spines in midlateral, lateral accessory and ventrolateral positions; lateroventral spine considerably stronger than those in same positions on segments 6 and 7, although not as strong as the spine on segment 8. Small rounded sieve plates present in sublateral positions. Sensory spots present in paradorsal, subdorsal, midlateral, and ventrolateral positions. Glandular cell outlets type 1 and posterior segment margin as on preceding segment (Figs 5A–B, 7I–J, 8G,).</p><p>SEGMENT 10. With laterodorsal tubes located near, but not at, posterior segment margin and small acicular spines in ventrolateral positions. Sensory spots present in subdorsal and ventrolateral positions. Glandular cell outlets type 1 present as two longitudinally arranged outlets in middorsal position and a pair in ventromedial positions. Posterior segment margin with thin but longer fringe tips between the laterodorsal tubes and along the concave margins of the sternal plates (Figs 5A–C, 7I, K, 8J–K).</p><p>SEGMENT 11. With lateral terminal spines. Females with thin lateral terminal accessory spines; males with three pairs of conspicuously long penile spines; especially the flexible and pointed dorsal and ventral pair are long, occasionally exceeding 100 µm, whereas the truncate and slightly more rigid median pair is shorter, around 54 µm. Sensory spots present in subdorsal positions, on inferior margins of tergal extensions. Glandular cell outlets type 1 were not observed. As is the case with all preceding segments, regular cuticular hairs are absent, but patches of very short triangular hairs are present on the sternal extensions. Tergal and sternal extensions are triangular with fine marginal fringes; tergal extensions are slightly longer than the sternal ones. A pair of rigid setae attaches on the outer lateral margins of the tergal extensions (Figs 5A–C, 7K–M, 8J–K).</p><p>Distribution</p><p>Antarctic Peninsula: Gerlache Strait and Andvord Bay MBA and IBB, 499 to 701 m b.s.l. See Fig. 1 for geographic overview of stations and Table 1 for station and specimen information.</p><p>Polymorphism</p><p>The species shows a relatively high level of polymorphism, expressed in the relatively frequent absence of small acicular spines and, less frequently, in the presence of additional small acicular spines. It is not possible to provide a complete overview of the polymorphism in the 30 examined specimens of P. grzelakae sp. nov., because some specimens were damaged and others (SEM specimens) were mounted in a way that prevented observation of all relevant characters. It is, however, still possible to get some indications. Out of the 30 specimens, eight showed a confirmed, identical distribution of tubes and spines (except for the sexually dimorphic ones). The two most frequent ‘abnormalities’ were the lack of small acicular spines in subdorsal positions, on either segment 4 or 5. Interestingly, the spines were never missing on both segments in the same specimen. Five specimens (paratype NHMD 1784250 from stn 1773, two SEM specimens from stn 1793, and two from stn 1832) were lacking subdorsal spines on segment 5, but showed otherwise no variation from the most common spine pattern. Another five (SEM specimens from stn 1706, 1793, 1809 and 1832) lacked subdorsal spines on segment 4, but only one of these (a male from stn 1793) showed additional variation by also lacking small acicular spines in midlateral positions of segment 4. Two SEM specimens from stn 1832 lacked small acicular spines in laterodorsal positions on segment 8, but otherwise all remaining observed variation was restricted to three specimens with their own unique spine combinations, expressed either as lack of spines or presence of additional spines. For example, one specimen (paratype USNM 1740027 from stn 1769) had a set of small acicular spines in ventromedial positions on segment 3, although such spines were absent in all other specimens, and another (SEM specimen from stn 1909) was missing small acicular spines in lateral accessory positions on segment 6, but had instead double pairs of small acicular spines in laterodorsal positions on this segment. A third specimen (SEM specimen from stn 1793) followed the most common spine pattern for P. grzelakae, but had in addition – as the only Polacanthoderes in all samples – small acicular spines in lateral accessory positions on segment 7. The seven remaining specimens also appeared to follow the common pattern but had, due to their condition or mounting orientation, characters that could not be confirmed visually.</p><p>Diagnostic remarks on Polacanthoderes grzelakae sp. nov.</p><p>With the addition of P. grzelakae sp. nov., Polacanthoderes now accommodates three species that all are restricted to the Antarctic continent (Sørensen 2008a; Yamasaki et al. 2022). The genus and its first described species, Polacanthoderes martinezi Sørensen, 2008, was described from the South Shetland Islands (Sørensen 2008a), and a phylogenetic analysis supported that Polacanthoderes represents a separate evolutionary linage within Echinoderidae (Sørensen 2008b) . One of the characters that makes Polacanthoderes stand out from other echinoderids is the numerous small acicular spines in rather unusual positions, i.e., subdorsal, laterodorsal, midlateral, and ventromedial (Sørensen 2008a).</p><p>Some years later, Yamasaki et al. (2022) described the second species of the genus, P. shiraseae . The species was described from Lützow-Holm Bay, Cape Damley, and near Totten Glacier, i.e., from Antarctic areas that geographically are pretty much opposite to the Antarctic Peninsula and South Shetland Island. Besides contributing with a new species, Yamasaki et al. (2022) also provided a redescription of P. martinezi and, in addition, shed light on the exceptionally high level of morphological variation within the two species (see following section for further discussion of polymorphism in species of Polacanthoderes). In a group like Echinoderidae, where much of the taxonomy traditionally has been based on the presence and position of spines and tubes, such variation can obviously lead to some taxonomic challenges. Yet, Yamasaki et al. (2022) explained how P. martinezi and P. shiraseae fairly easily could be distinguished by the conspicuously stronger lateroventral spines on segments 8 and 9 in P. shiraseae, and by the position of short acicular spines on segment 7, which appear in lateral accessory positions in P. martinezi and in sublateral positions in P. shiraseae . The latter character might seem like a very subtle alteration, open for subjective interpretation, but when observed the difference is in fact very distinct, and since both species otherwise have a series of short lateral accessory acicular spines on segments 6 to 9, it is easy to detect the sublateral displacement of the spines on segment 7 in P. shiraseae .</p><p>The new species, P. grzelakae sp. nov., very clearly shares most characters with P. shiraseae, including the strong lateroventral spines on segments 8 and 9, and the sublateral short acicular spines on segment 7. Thus, P. grzelakae is easily distinguished from P. martinezi . The characters that separate P. grzelakae from both congeners are the presence of subdorsal and ventrolateral tubes on segment 2. In the present study, a total of 38 specimens of Polacanthoderes were examined. Out of these, four specimens had no tubes on segment 2 and were thus identified as P. shiraseae . Thirty other specimens had both subdorsal and ventrolateral tubes on segment 2, and were assigned to P. grzelakae . Of the remaining four specimens, three had only subdorsal tubes on segment 2, whereas a single specimen had only ventrolateral tubes.</p><p>In light of the known morphological variation within species of Polacanthoderes (and without access to molecular barcoding data), it is obviously not straightforward to determine whether P. grzelakae sp. nov. is a distinct species or a morphological variation of P. shiraseae . However, a strong argument favours the first option. Recently, Anguas-Escalante et al. (2023) demonstrated with molecular barcoding that the presence or absence of tubes on segment 2 in otherwise very similar species of Echinoderes actually should be seen as species diagnostic. In P. grzelakae the species diagnostic trait is exactly expressed as the presence of tubes on segment 2, and these tubes are consistently present within the type series of the species, whereas the morphological variation we observe is mostly expressed in the presence/absence of short acicular spines in the dorsal series on segments 4, 5, and 8 (see below for further discussion of this).</p><p>Based on these arguments, we propose P. grzelakae sp. nov. as a new species showing close resemblance with P. shiraseae, but distinguished by the presence of subdorsal and ventrolateral tubes on segment 2. This proposal seems fair, but it is admittedly challenged by the four remaining specimens, Polacanthoderes sp. 1 and P. sp. 2, that show variation in their tubes on segment 2. With tubes only in either subdorsal or ventrolateral positions on segment 2, the four specimens fall in between the two species, and the number of potential explanations are too numerous to allow a final conclusion. The two morphotypes could represent the bridging between P. shiraseae and P. grzelakae, suggesting that they are all conspecific; they could represent another two distinct species; or they could be results of hybridisation between P. shiraseae and P. grzelakae . It would require molecular barcoding to solve this question, and any other conclusion at this point would be nothing but speculation. However, based on the arguments above, we find it justified to consider P. grzelakae as a new, easily distinguishable species of Polacanthoderes .</p><p>The distribution pattern of glandular cell outlets type 1 in P. grzelakae sp. nov. follows the MD Seg. 1–3, PD 4–9 pattern (see table with summary of species with this pattern described up to 2020 in Sørensen et al. 2020). The same pattern is present in both Polacanthoderes congeners (Sørensen 2008a; Yamasaki et al. 2022).</p></div>	https://treatment.plazi.org/id/03AE4066FFAED453174AFDB9FCD7FE20	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Sørensen, Martin V.;Macheriotou, Lara;Braeckman, Ulrike;Smith, Craig R.;Ingels, Jeroen	Sørensen, Martin V., Macheriotou, Lara, Braeckman, Ulrike, Smith, Craig R., Ingels, Jeroen (2025): Antarctic Kinorhyncha: Seven new species from the Antarctic Peninsula. European Journal of Taxonomy 1000 (1): 1-102, DOI: 10.5852/ejt.2025.1000.2947, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2947/13307
03AE4066FFA1D45314F6FDCEFE86FAB6.text	03AE4066FFA1D45314F6FDCEFE86FAB6.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Polacanthoderes shiraseae Yamasaki 2022	<div><p>Polacanthoderes shiraseae Yamasaki et al., 2022</p><p>Material examined</p><p>ANTARCTICA – Antarctic Peninsula • 1 ♂, 1 ♀ (mounted for LM in Fluoromount G on HS slide); CRS 1763; 64°48.41′ S, 65°21.82′ W; 593 m b.s.l.; 3 Apr. 2016; FjordEco2; soft sediment; NHMD 1784624, 1784625 • 2 ♀♀ (mounted for LM in Fluoromount G on HS slide); CRS 1846; 64°47.93′ S, 65°21.23′ W; 572 m b.s.l.; 25 Apr. 2016; FjordEco2; soft sediment; NHMD 1784626, 1784627 .</p><p>Short description</p><p>Four adult specimens (one male and three females) from two different stations (stn 1763 and stn 1846) were measured and examined with light microscopy.All four specimens perfectly fit the species diagnosis of P. shiraseae (see Yamasaki et al. 2022), i.e., without tubes on segment 2 and with the short acicular spines on segment 7 placed in sublateral rather than lateral accessory positions. None of the specimens had short subdorsal acicular spines on segments 4 or 5. On segment 8, two specimens had short acicular spines in positions corresponding to subdorsal sensu Yamasaki et al. (2022), whereas such spines were missing in the other two specimens. All measurements were within the ranges of those reported in the original description of P. shiraseae .</p><p>Distribution</p><p>Antarctic Peninsula: only on the open continental shelf off the Peninsula, 572 to 593 m b.s.l. (Fig. 1C, Table 1). The species has in addition been recorded at Lützow-Holm Bay, Cape Damley, and near Totten Glacier (Yamasaki et al. 2022), i.e., on the opposite side of the Antarctic continent (see red dots in Fig. 1A).</p></div>	https://treatment.plazi.org/id/03AE4066FFA1D45314F6FDCEFE86FAB6	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Sørensen, Martin V.;Macheriotou, Lara;Braeckman, Ulrike;Smith, Craig R.;Ingels, Jeroen	Sørensen, Martin V., Macheriotou, Lara, Braeckman, Ulrike, Smith, Craig R., Ingels, Jeroen (2025): Antarctic Kinorhyncha: Seven new species from the Antarctic Peninsula. European Journal of Taxonomy 1000 (1): 1-102, DOI: 10.5852/ejt.2025.1000.2947, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2947/13307
03AE4066FFA1D4521796FA5DFA8DFE87.text	03AE4066FFA1D4521796FA5DFA8DFE87.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Polacanthoderes undefined-1	<div><p>Polacanthoderes sp. 1</p><p>Material examined</p><p>ANTARCTICA – Antarctic Peninsula • 1 ♂ (mounted for SEM); CRS 1767; 64°47.99′ S, 65°20.55′ W; 590 m b.s.l.; 4 Apr. 2016; FjordEco2; soft sediment; MVS • 1 ♂ (mounted for SEM); CRS 1776; 64°52.53′ S, 62°33.90′ W; 551 m b.s.l.; 7 Apr. 2016; FjordEco2; soft sediment; MVS • 1 ♂ (mounted for SEM); CRS 1809; 64°39.59′ S, 62°55.09′ W; 694 m b.s.l.; 15 Apr. 2016; FjordEco2; soft sediment; MVS .</p><p>Short description</p><p>Three adult males were examined with scanning electron microscopy. The morphology of the specimens closely follows the species diagnosis of P. grzelakae sp. nov., except for the missing ventrolateral tubes on segment 2. Short subdorsal acicular spines on segment 4 are missing in all three specimens but are present on segment 5. On segment 8, laterodorsal short acicular spines are present in two specimens and missing in one.</p><p>Distribution</p><p>Antarctic Peninsula: open continental shelf, Gerlache Strait, and Andvord Bay IBB, 551 to 694 m b.s.l. See Fig. 1 for geographic overview of stations and Table 1 for station and specimen information.</p></div>	https://treatment.plazi.org/id/03AE4066FFA1D4521796FA5DFA8DFE87	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Sørensen, Martin V.;Macheriotou, Lara;Braeckman, Ulrike;Smith, Craig R.;Ingels, Jeroen	Sørensen, Martin V., Macheriotou, Lara, Braeckman, Ulrike, Smith, Craig R., Ingels, Jeroen (2025): Antarctic Kinorhyncha: Seven new species from the Antarctic Peninsula. European Journal of Taxonomy 1000 (1): 1-102, DOI: 10.5852/ejt.2025.1000.2947, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2947/13307
03AE4066FFA0D4521796FE6DFD75FC3F.text	03AE4066FFA0D4521796FE6DFD75FC3F.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Polacanthoderes undefined-2	<div><p>Polacanthoderes sp. 2</p><p>Material examined</p><p>ANTARCTICA • 1 ♂ (mounted for SEM); Antarctic Peninsula, CRS 1776; 64°52.53′ S, 62°33.90′ W; 551 m b.s.l.; 7 Apr. 2016; FjordEco2; soft sediment; MVS .</p><p>Short description</p><p>One adult male was examined with scanning electron microscopy. The morphology of the specimens closely follows the species diagnosis of P. grzelakae sp. nov., except for the missing subdorsal tubes on segment 2. Subdorsal short acicular spines are present on segment 4, but missing on segment 5. Short laterodorsal acicular spines are present on segment 8.</p><p>Distribution</p><p>Antarctic Peninsula: Andvord Bay IBB, 551 m b.s.l. See Fig. 1 for geographic overview of stations and Table 1 for station and specimen information.</p></div>	https://treatment.plazi.org/id/03AE4066FFA0D4521796FE6DFD75FC3F	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Sørensen, Martin V.;Macheriotou, Lara;Braeckman, Ulrike;Smith, Craig R.;Ingels, Jeroen	Sørensen, Martin V., Macheriotou, Lara, Braeckman, Ulrike, Smith, Craig R., Ingels, Jeroen (2025): Antarctic Kinorhyncha: Seven new species from the Antarctic Peninsula. European Journal of Taxonomy 1000 (1): 1-102, DOI: 10.5852/ejt.2025.1000.2947, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2947/13307
03AE4066FFA3D45015BEFAA0FE3AFBEC.text	03AE4066FFA3D45015BEFAA0FE3AFBEC.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Polacanthoderes Sorensen 2008	<div><p>Remarks on polymorphism in Polacanthoderes spp.</p><p>The description of P. shiraseae also includes a careful re-examination of available P. martinezi specimens (eleven in total), and from both species Yamasaki et al. (2022) reported a relatively high level of intraspecific variation regarding tubes and short acicular spines. Among specimens of P. martinezi they found that a few specimens would have subdorsal tubes on segment 2, subdorsal tubes or short acicular spines on segment 5, and short subdorsal acicular spines on segment 8, whereas the majority of the available specimens would lack these structures. Likewise, they reported the occasional, but yet rather rare, presence of short subdorsal acicular spines on segments 4, 5, and 8 in P. shiraseae .</p><p>The new species, P. grzelakae sp. nov., also shows intraspecific variation, which contributes further to the taxonomic challenges. As with P. shiraseae, the polymorphism in P. grzelakae also appears to be expressed mostly in the dorsal series on segments 4, 5, and 8. Of 30 examined specimens, five lacked short subdorsal spines on segment 4, whereas five different specimens had no such spines on segment 5. In addition, another two specimens (of which neither showed spine loss on segments 4 or 5) lacked short laterodorsal acicular spines on segment 8. Additional spine variation was restricted to singletons and included: one specimen with short ventromedial acicular spines on segment 3; one without midlateral tubes on segment 4; one with two pairs of closely positioned, short laterodorsal acicular spines on segment 6; one without short lateral accessory acicular spines on segment 6 (same specimen as the one with double pairs of segment 6 laterodorsal spines); and one specimen with both short sublateral and short lateral accessory acicular spines on segment 7 (all other specimens have no lateral accessory spine on this segment).</p><p>The present description of P. grzelakae sp. nov. is based on 30 specimens, whereas Yamasaki et al. (2022) examined around 50 specimens for their description of P. shiraseae . One could obviously always wish for even larger sample sizes, but they still represent enough specimens to provide some hints about where the variation is most expressed and where the differences should be seen as rarities. The data leaves the impression that while all regular acicular spines occur consistently across specimens of Polacanthoderes, nearly all tubes and small acicular spines can potentially vary. However, much of this variation is restricted to singletons and is therefore to some extent neglectable. In both species, higher frequencies of variation are only reached in the occurrence of small acicular spines in the dorsal series of segments 4, 5, and 8. For instance, small subdorsal acicular spines were absent on either segment 4 or 5 in one third of the P. grzelakae specimens.</p><p>As mentioned previously, such levels of morphological variation obviously represent a taxonomic challenge for present and future studies of Polacanthoderes, but understanding this polymorphism also makes it easier to comprehend. Thus, we need to acknowledge that eventual future species descriptions of Polacanthoderes spp. have to be based on a sufficiently high number of specimens to be able to detect polymorphic characters. In addition, it can be helpful to keep in mind that we can expect more variation on segments 4, 5, and 8, which in turn makes characters on these particular segments less suitable as species diagnostic.</p></div>	https://treatment.plazi.org/id/03AE4066FFA3D45015BEFAA0FE3AFBEC	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Sørensen, Martin V.;Macheriotou, Lara;Braeckman, Ulrike;Smith, Craig R.;Ingels, Jeroen	Sørensen, Martin V., Macheriotou, Lara, Braeckman, Ulrike, Smith, Craig R., Ingels, Jeroen (2025): Antarctic Kinorhyncha: Seven new species from the Antarctic Peninsula. European Journal of Taxonomy 1000 (1): 1-102, DOI: 10.5852/ejt.2025.1000.2947, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2947/13307
03AE4066FFA2D4661767FB41FC81F851.text	03AE4066FFA2D4661767FB41FC81F851.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Echinoderes ahlfeldae Sørensen & Macheriotou & Braeckman & Smith & Ingels 2025	<div><p>Echinoderes ahlfeldae sp. nov</p><p>urn:lsid:zoobank.org:act: E59B6DA9-45BD-4DE8-80E6-16529FBEC3A1</p><p>Figs 9–12, Tables 9–10</p><p>Diagnosis</p><p>Echinoderes with acicular spines in middorsal position on segments 4, 6, and 8, and in lateroventral positions on segments 6 to 9. Tubes present in subdorsal and ventrolateral positions on segment 2, in lateroventral positions on segment 5, in sublateral positions on segment 8, and in laterodorsal positions on segment 10; tubes on segment 10 show sexual dimorphism and are longer in males. Sieve plates on segment 9 in sublateral positions. Males with flare-like extensions from secondary fringe of sternal plates on segment 10. Female papillae or glandular cell outlets type 2 not present. Dorsal glandular cell outlets type 1 are present in middorsal positions on segments 1 to 3, 5, 7, and 10, and in paradorsal positions on segments 4, 6, 8, and 9.</p><p>Etymology</p><p>The species name is dedicated to Katie Ahlfeld, museum specialist at the USNM, in appreciation of her work maintaining the Smithsonian invertebrate collections and of the numerous kinorhynch loans she has issued to the first author.</p><p>Material examined</p><p>Holotype ANTARCTICA • ♀ (mounted for LM in Fluoromount G on HS slide); Antarctic Peninsula, CRS 1792; 64°51.40′ S, 62°34.01′ W; 525 m b.s.l.; 11 Apr. 2016; FjordEco2; soft sediment; NHMD 1784759.</p><p>Paratypes</p><p>ANTARCTICA – Antarctic Peninsula • 7 ♂♂ (mounted as holotype); CRS 1698; 64°51.60′ S, 62°33.80′ W; 541 m b.s.l.; 28 Nov. 2015; FjordEco1; soft sediment; NHMD 1784762 to 1784766, USNM 1740029 to 1740030 • 1 ♂ (mounted as holotype); CRS 1769; 64°52.37′ S, 62°25.27′ W; 547 m b.s.l.; 5 Apr. 2016; FjordEco2; soft sediment; NHMD 1784768 • 4 ♂♂, 2 ♀♀ (mounted as holotype); CRS 1790; 64°51.49′ S, 62°34.01′ W; 532 m b.s.l.; 10 Apr. 2016; FjordEco2; soft sediment; NHMD 1784770 to 1784773, USNM 1740031 to 1740032 • 1 ♂, 2 ♀♀ (mounted as holotype); same data as for holotype; NHMD 1784760 to 1784761, USNM 1740033 • 1 ♂ (mounted as holotype); CRS 1793; 64°39.53′ S, 62°55.03′ W; 701 m b.s.l.; 11 Apr. 2016; FjordEco2; soft sediment; NHMD 1784774 • 6 ♂♂, 5 ♀♀ (mounted as holotype); CRS 1809; 64°39.59′ S, 62°55.09′ W; 694 m b.s.l.; 15 Apr. 2016; FjordEco2; soft sediment; NHMD 1784775 to 1784782, USNM 1740034 to 1740036 .</p><p>Additional material</p><p>ANTARCTICA – Antarctic Peninsula • 2 ♂♂, 1 ♀ (mounted for SEM); CRS 1698; 64°51.60′ S, 62°33.80′ W; 541 m b.s.l.; 28 Nov. 2015; FjordEco1; soft sediment; MVS • 1 juv. (mounted as holotype); CRS 1698; 64 o 51.60′ S, 62 o 33.80′ W; 541 m b.s.l.; 28 Nov. 2015; FjordEco1; soft sediment; NHMD 1784767 • 1 ♂ (mounted for SEM); CRS 1773; 64°52.35′ S, 62°25.88′ W; 553 m b.s.l.; 6 Apr. 2016; FjordEco2; soft sediment; MVS • 4 ♂♂, 2 ♀♀ (mounted for SEM); same data as for holotype; MVS • 12 ♂♂, 7 ♀♀ (mounted for SEM); CRS 1793; 64°39.53′ S, 62°55.03′ W; 701 m b.s.l.; 11 Apr. 2016; FjordEco2; soft sediment; MVS • 4 ♂♂, 1 ♀ (mounted for SEM); CRS 1799; 64°51.51′ S, 62°33.83′ W; 541 m b.s.l.; 13 Apr. 2016; FjordEco2; soft sediment; MVS • 11 ♂♂, 6 ♀♀ (mounted for SEM); CRS 1809; 64°39.59′ S, 62°55.09′ W; 694 m b.s.l.; 15 Apr. 2016; FjordEco2; soft sediment; MVS • 1 ♂, 7 ♀♀ (mounted for SEM); CRS 1832; 64°39.30′ S, 62°55.98′ W; 631 m b.s.l.; 21 Apr. 2016; FjordEco2; soft sediment; MVS .</p><p>Description</p><p>GENERAL. Adults with head, neck and eleven trunk segments (Figs 9, 10, 11A, 12A–B). An overview of measurements and dimensions is given in Table 9. Distributions of cuticular structures, i.e., sensory spots, glandular cell outlets, spines, and tubes, are summarized in Table 10.</p><p>HEAD. Consists of a retractable mouth cone and an introvert (Figs 10, 12C–D). Mouth cone with nine outer oral styles composed of two units; all oral styles with uniform morphology, but differ alternatingly in length, with styles in uneven numbered sectors being ca 15% longer than those in even numbered (Fig. 12C). A partly folded structure with seven spikes (lateral ones longest) is present at the base of each outer oral style. A set of double fringes is located more basally, at the base of the mouth cone and in between the attachment points of the outer oral styles. Inner oral styles could not be examined.</p><p>INTROVERT. With ten primary spinoscalids in Ring 01 (Fig. 10). Each primary spinoscalid consists of a basal sheath and a distal end piece with a blunt tip (Fig. 12D). The sheaths have two transverse fringes; the most proximal fringe has the strongest fringe tips. End-pieces are flexible, with two longitudinal fringes on their proximal parts, whereas they are smooth on their distal halves. Rings 02 and 04 have 10 spinoscalids, and Rings 03 and 05 have 20. All spinoscalids in these rings are well-developed and consist of a basal sheath and a pointed end-piece. Ring 06 has only six spinoscalids, located in sectors 1, 3, 5, 6, 7, and 9; they resemble those in preceding sectors, but the distal end-pieces are much shorter, only slightly longer than their proximal sheaths. Ring 07 has two kinds of scalids: one kind resembles those in Ring 06 and are located as pairs in sectors 3 and 9; the other kind resembles trichoscalids (Fig. 12D). They have the same bushy appearance, but are much smaller than the actual trichoscalids. These trichoscalid-like scalids are present as pairs in sectors 1, 2, 4, 8, and 10, and as single, laterally displaced ones in sectors 5 and 7 (Fig. 10). Described sector-wise (Fig. 10), sector 1 has its scalids arranged as two double diamonds, anterior to a pair of trichoscalid-like scalids. Sectors 3 and 9 are similar, and also have their spinoscalids arranged as two double diamonds but anterior to a pair of regular scalids. Sectors 2, 4, 8, and 10 all have spinoscalids arranged as a quincunx, located in between an anterior spinoscalid in Ring 02, a posterior pair of trichoscalid-like scalids, and a trichoscalid plate. Sectors 5 and 7 have spinoscalids forming double diamonds, anterior to an unpaired, lateral trichoscalid-like scalid and a trichoscalid plate. Regular trichoscalids with trichoscalid plates are present in sectors 2, 4, 5, 7, 8, and 10.</p><p>NECK. With 16 placids. Midventral placid broadest, 17 µm in width and length, whereas all others are narrower, measuring 10 µm in width at their bases. The trichoscalid plates are well-developed and hat-shaped.</p><p>SEGMENT 1. Consists of a complete cuticular ring. Sensory spots are present in subdorsal, laterodorsal, and ventromedial positions; subdorsal and laterodorsal sensory spots are present on the anterior half of the segment, but not immediately at the anterior margin. They are composed of a dense tuft of micropapillae around a central pore and are flanked by four to five, irregularly arranged, strong and bristle-like cuticular hairs; ventromedial sensory spots are more posterior, with same appearance as the dorsal ones, but with only two or three cuticular hairs. Glandular cell outlets type 1 are present in middorsal and ventrolateral positions. Besides the few hairs around the sensory spots, the segment has either no cuticular hairs at all, or only very few rigid and bristle-like hairs on the dorsal side. The posterior segment margin is straight and terminates in a well-developed pectinate fringe with broad fringe tips (Figs 9A–B, 11B–C, 12E–G).</p><p>SEGMENT 2. Consists of a complete cuticular ring; some specimens mounted for SEM had indications of a weak, superficial tergosternal line (Fig. 12F), but this line did not occur consistently in all SEM specimens, and none of the specimens mounted for LM had any indications of plate differentiation. Tubes are located in subdorsal and ventrolateral positions; missing tubes in some specimens were evidently broken off. Sensory spots present in middorsal, laterodorsal, and ventromedial positions. The micropapillary areas around the sensory spots on this, and all following segments, are more oval; the micropapillae along the posterior margins of the areas are slightly longer, and one to three very long, hair-like micropapillae extend from the posterior part of the areas. Glandular cell outlets type 1 are present in middorsal and ventromedial positions. Bracteate cuticular hairs are arranged in three transverse rows from the middorsal to the midlateral positions; hairs in the two anteriormost rows are rather short, whereas those of the third row are considerably longer, reaching the pectinate fringe at the posterior segment margin; the ventral half of the segment is devoid of cuticular hairs. The posterior segment margin is straight along the dorsal and lateral sides, but extends in a small midventral V-shaped flap. Pectinate fringe as on preceding segment (Figs 9A–B, 11B–C, 12E–G).</p><p>SEGMENT 3. As remaining segments, consisting of one tergal and two sternal plates. Sensory spots are present in subdorsal and sublateral positions, and glandular cell outlets type 1 in middorsal and ventromedial positions. The hair covering of the tergal and lateral halves of sternal plates is dense on the anterior half of the segment, except in hair-less midlateral areas; bracteate cuticular hairs are arranged in six to seven rows, with hairs getting gradually longer in the more posterior rows; the hairs in the most posterior row are considerably longer than the others. Paraventral areas without bracteate hairs, but with fine, short hair-like extensions. Posterior segment margin straight and pectinate fringe as on preceding segment (Figs 9A–B, 11B–C, 12E).</p><p>SEGMENT 4. With spine in middorsal position. Sensory spots are not present. Glandular cell outlets type 1 are present in paradorsal and ventromedial positions. Cuticular hairs as on preceding segment, but in addition to the hairless midlateral areas, the mid- and paradorsal areas are also devoid of hairs. Posterior segment margin and pectinate fringe as on preceding segment (Figs 9A–B, 11B–C, 12E).</p><p>SEGMENT 5. With tubes in lateroventral positions. Sensory spots present in subdorsal, sublateral and ventromedial positions, and glandular cell outlets type 1 in middorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 9A–B, 11B–C, 12E).</p><p>SEGMENT 6. With spines in middorsal and lateroventral positions. Sensory spots present in paradorsal, subdorsal, sublateral, and ventromedial positions. Glandular cell outlets type 1 present in paradorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 9A–B, 11B–C).</p><p>SEGMENT 7. With spines in lateroventral positions. Sensory spots present in paradorsal, sublateral, and ventromedial positions. Glandular cell outlets type 1 present in middorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 9A–B, 11B–E, 12I–J).</p><p>SEGMENT 8. With spines in middorsal and lateroventral positions, and tubes in sublateral positions. Sensory spots present in paradorsal positions only. Glandular cell outlets type 1 present in paradorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 9A–B, 11D–E, G, 12H–J).</p><p>SEGMENT 9. With spines in lateroventral positions. Sensory spots present in paradorsal (posterior on segment), subdorsal (anterior on segment), laterodorsal (medial on segment), and ventrolateral (medial on segment) positions. Glandular cell outlets type 1 present in paradorsal and ventromedial positions. Small rounded sieve plates located in sublateral positions; gaps between sieve plates and lateroventral spines are distinct. The cuticular hair covering is similar to that on preceding segments, but hairless middorsal area is broader, and the hairless lateral areas are in laterodorsal, rather than midlateral positions. Posterior segment margin and pectinate fringe as on preceding segment (Figs 9A–B, 11D–E, G–H, 12H).</p><p>SEGMENT 10. With sexually dimorphic laterodorsal tubes located near, but not at, the posterior segment margin; female tubes are extremely small, hardly projecting from attachment site; male tubes of more regular size, reaching beyond the segment margin. An additional sexually dimorphic trait is expressed in the secondary fringe, enwrapping the anterior part of the segment; at most other segments the secondary fringe is covered by the free flap of the preceding segment, but in male specimens, a tuft of long setae expands from the secondary fringe on each sternal plate and reaches more than halfway down the exposed part of the segment (Figs 9D, 11F, H–I, 12K). In some specimens, the setal extensions appear rather disorganised, but in others they are very well-arranged and spread out from a common shaft, forming a fan- or flare-like structure. Due to this appearance, the structures will be referred to as ‘flare-like extensions from secondary fringe’. No indication of a similar structure is evident in females. Sensory spots present in subdorsal and ventrolateral positions. Glandular cell outlets type 1 present as two longitudinally arranged outlets in middorsal position and in ventromedial positions. Cuticular hairs of uniform length, covering the tergal plate, except in two hairless subdorsal areas; cuticular hairs on sternal plates as on preceding segments. The posterior segment margin of the tergal plate is straight, with very minute fringe tips; the margins of the sternal plates are concave, reaching the posterior margin of the terminal segment, also with very short fringe tips (Figs 9A–D, 11D–F, H–K, 12K–N).</p><p>SEGMENT 11. With lateral terminal spines. Females with lateral terminal accessory spines; males with thin, tubular dorsal and ventral penile spines, and a well-developed, cone-shaped medial pair of penile spines. Sensory spots present in ventromedial positions, near margins of sternal extensions. A single glandular cell outlet type 1 present in middorsal position. A minute middorsal protuberance-like structure extends from the intersegmentary joint in some specimens (Fig. 12M), whereas it is evidently absent in others (Fig. 12N); holotype without middorsal protuberance. The segment is devoid of cuticular hairs, but with very short cuticular hair-like structures covering the mid- and paradorsal areas, and the inferior margins of the tergal extensions. Tergal extensions are short and triangular with slightly offset tips. Sternal extensions short, broadly rounded, and not extending beyond tergal extensions (Figs 9A–D, 11I–K, 12L–N).</p><p>Distribution</p><p>Antarctic Peninsula: Gerlache Strait and Andvord Bay MBA, IBB and OBA, 525 to 701 m b.s.l. See Fig. 1 for geographic overview of stations and Table 1 for station and specimen information.</p><p>Diagnostic remarks</p><p>The composition of segments 1 and 2 forming closed cuticular rings easily assigns the new species to Echinoderes . This generic assignment could, if genus diagnoses of Echinoderidae are used in the strictest possible way, be challenged by the presence of superficial markings on segment 2, which could indicate the presence of partial tergosternal junctions. However, several previous descriptions have demonstrated that a weak indication of a partially developed midventral fissure on segment 2 does not bring the generic assignments to Echinoderes into question (Sørensen et al. 2012; Herranz et al. 2018; Yamasaki &amp; Dal Zotto 2019; Grzelak et al. 2023). In the case of E. ahlfeldae sp. nov. the superficial fissures on segment 2 are lateroventral rather than midventral, which to our knowledge has not been observed previously among species of Echinoderidae, but since the indications are only superficial lines on the cuticle, never observable with LM, and not even occurring in all specimens, we would not put any taxonomic value into this trait. Instead, it only confirms that the ring-like composition of segment 2 might show a certain level of variation within Echinoderes .</p><p>Among species of Echinoderes, E. ahlfeldae sp. nov. shares the common pattern with middorsal spines on segments 4, 6, and 8, and lateroventral tubes or spines on segments 5 to 9, with no less than 27 congeners (Yamasaki et al. 2020b). However, if this tube-spine pattern is combined with the presence of sublateral tubes on segment 8 and the complete lack of glandular cell outlets type 2, the list of similar candidates is shortened dramatically to only three species, i.e., E. hispanicus Pardos et al., 1998, E. leduci Grzelak &amp; Sørensen, 2022, and E. newcaledoniensis Higgins, 1967 . These three species certainly show great resemblance to each other and to E. ahlfeldae, but still they can be distinguished from the latter by carrying additional pairs of tubes in various positions. Likewise, E. newcaledoniensis has laterodorsal and sublateral tubes on segment 2, whereas subdorsal tubes are lacking, and it has in addition midlateral tubes on segment 9 and lateral accessory tubes on segments 6 to 8 (Higgins 1967). Also E. hispanicus differs, by having sublateral tubes on segment 2 and lateral accessory tubes or spines on segment 8 (Pardos et al. 1998). The species showing the closest resemblance to E. ahlfeldae is E. leduci . However, E. leduci differs by its uncommon lack of regular cuticular hairs that have been replaced by minute scales, by having laterodorsal tubes on segment 9, and by having its dorsal tubes on segment 2 in laterodorsal rather than subdorsal positions (Grzelak &amp; Sørensen 2022). Even without taking the lack of glandular cell outlets type 2 into account, the combined spine and tube pattern in E. ahlfeldae is unique within the genus, which makes identification of the species fairly easy.</p><p>The distribution of glandular cell outlets type 1 in E. ahlfeldae sp. nov. follows the MD Seg. 1–3, 5, 7, PD 4, 6, 8–9 pattern (see table with summary of species with this pattern described up to 2020 in Sørensen et al. 2020). Among species described after 2020, this pattern is also found in E. leduci, which stresses the close resemblance between the two species.</p><p>Two other noteworthy characters in E. ahlfeldae sp. nov. are the position of the sieve plates and the uncommon flare-like extensions from the secondary fringes of the sternal extensions of segment 10 in males. The sieve plates in species of Echinoderes are most commonly located in lateral accessory positions on segment 9, but a slight relocation to sublateral positions is not uncommon either. Therefore, the sieve plate positions rarely play an important role as a diagnostic character. However, during the species identification phase of the present study, their positions turned out to be an extremely handy character when distinguishing between E. ahlfeldae and E. nataliae sp. nov. (see description below). The two species have a rather similar appearance, especially when it comes to specimens mounted for SEM, with only the ventral and parts of the lateral sides exposed. However, in E. nataliae the sieve plates sit in lateral accessory positions, very close to the lateroventral spines, and soon during the identification phase the position of the sieve plates became the easy way to distinguish between the two species when other diagnostic characters were hidden. This example shows that even the most unexpected character trait can suddenly become useful in species recognition.</p><p>Another subtle, but yet significant trait of E. ahlfeldae sp. nov. is the flare-like extensions from the secondary fringes of the sternal plates on segment 10 in male specimens. When first observed, the flare-like structures were considered to be unique for the species, because something like this was certainly never reported previously. The most similar, and also the only, published example of a structure like this are the tufts of long hairs reported from Echinoderes pterus Yamasaki et al., 2018a . However, the structures in E. pterus differ in several points: they are much stronger and appear more like a brush; they are present on the tergal plate and on segment 9; and they are present in both sexes. Thus, the similarities between the hairy tufts in E. pterus and the flare-like extensions in E. ahlfeldae are only superficial, and the structures in the latter species were therefore initially considered to be limited to this particular species. However, as discussed above, the similarities between E. ahlfeldae and E. leduci led to a closer examination of unpublished SEM images of the latter species and, surprisingly, similar structures were found in this species. In E. leduci they also appear on the sternal plates of segment 10 and were found in two males mounted for SEM (their presence in females could not be confirmed though, as the only available female mounted for SEM was mounted on its ventral side). Their appearance and position in E. leduci clearly suggest that the structures are homologous with the flare-like extensions in E. ahlfeldae, but they also showed clear differences. Whereas the flares in E. ahlfeldae consist of six to eight setal threads, only one to three threads were present in E. leduci . This obviously makes the structure much more indistinct, which also explains why they were not mentioned in the original description (Grzelak &amp; Sørensen 2022). In addition to the occurrence in these two species, similar setal threads was found in one of the new species, E. nataliae sp. nov. (see following description). In this species, the setal threads are also restricted to males and are formed as extensions from the secondary fringe of the sternal plates of segment 10. However, in E. nataliae only a single thread is present on each sternal plate, in contrast to the more numerous threads found in E. ahlfeldae .</p></div>	https://treatment.plazi.org/id/03AE4066FFA2D4661767FB41FC81F851	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Sørensen, Martin V.;Macheriotou, Lara;Braeckman, Ulrike;Smith, Craig R.;Ingels, Jeroen	Sørensen, Martin V., Macheriotou, Lara, Braeckman, Ulrike, Smith, Craig R., Ingels, Jeroen (2025): Antarctic Kinorhyncha: Seven new species from the Antarctic Peninsula. European Journal of Taxonomy 1000 (1): 1-102, DOI: 10.5852/ejt.2025.1000.2947, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2947/13307
03AE4066FF97D47D1768FED7FE1FFA98.text	03AE4066FF97D47D1768FED7FE1FFA98.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Echinoderes nataliae Sørensen & Macheriotou & Braeckman & Smith & Ingels 2025	<div><p>Echinoderes nataliae sp. nov urn:lsid:zoobank.org:act: B64378E9-7DF2-481E-BAE4-9B76D26E4819</p><p>Figs 13–15, Tables 11–12</p><p>Diagnosis</p><p>Echinoderes with acicular spines in middorsal position on segments 4, 6, and 8, and in lateroventral positions on segments 6 to 9. Tubes present in subdorsal (almost paradorsal), laterodorsal, sublateral, and ventrolateral positions on segment 2, in lateroventral positions on segment 5, in sublateral positions on segment 8, and in laterodorsal positions on segment 10; tubes on segment 10 show sexual dimorphism and are larger in males. Laterodorsal glandular cell outlet type 2 with short, broad, projecting rectangular flap present on segment 9. Dorsal glandular cell outlets type 1 are present in middorsal positions on segments 1 to 3, 5, 7, and 10, and in paradorsal positions on segments 4, 6, 8, and 9. Sieve plates on segment 9 in lateral accessory positions, very close to base of lateroventral spine. Segment 1 completely devoid of cuticular hairs, except for those flanking the sensory spots. Males with single setal extension from secondary fringe of sternal plates on segment 10. Female papillae not present.</p><p>Etymology</p><p>The first author dedicates this species to his wife, Natalia Pouchkina-Stantcheva.</p><p>Material examined</p><p>Holotype ANTARCTICA • ♂ (mounted for LM in Fluoromount G on HS slide); Antarctic Peninsula, CRS 1778; 64°47.01′ S, 62°43.90′ W; 567 m b.s.l.; 8 Apr. 2016; FjordEco2; soft sediment; NHMD 1786668.</p><p>Paratypes</p><p>ANTARCTICA – Antarctic Peninsula • 1 ♂ (mounted as holotype); CRS 1706; 64°50.47′ S, 62°35.12′ W; 499 m b.s.l.; 1 Dec. 2015; FjordEco1; soft sediment; NHMD 1786672 • 1 ♂ (mounted as holotype); CRS 1716; 64°52.36′ S, 62°25.49′ W; 551 m b.s.l.; 6 Dec. 2015; FjordEco2; soft sediment; NHMD 1786673 • 1 ♀ (mounted as holotype); CRS 1773; 64°52.35′ S, 62°25.88′ W; 553 m b.s.l.; 6 Apr. 2016; FjordEco2; soft sediment; NHMD 1786674 • 3 ♂♂, 2 ♀♀ (mounted as holotype); same data as for holotype; NHMD 1784769 to 1784771, USNM 1740037 to 1740038 • 2 ♂♂, 1 ♀, 1 juv. (mounted as holotype); CRS 1790; 64°51.49′ S, 62°34.01′ W; 532 m b.s.l.; 10 Apr. 2016; FjordEco2; soft sediment; NHMD 1786675 to 1786676, USNM 1740039 • 1 ♂ (mounted as holotype); CRS 1792; 64°51.40′ S, 62°34.01′ W; 525 m b.s.l.; 11 Apr. 2016; FjordEco2; soft sediment; NHMD 1786679 • 1 ♂ (mounted as holotype); CRS 1799; 64°51.51′ S, 62°33.83′ W; 541 m b.s.l.; 13 Apr. 2016; FjordEco2; soft sediment; NHMD 1786680 .</p><p>Additional material</p><p>ANTARCTICA – Antarctic Peninsula • 1 ♀ (mounted for SEM); CRS 1698; 64°51.60′ S, 62°33.80′ W; 541 m b.s.l.; 28 Nov. 2015; FjordEco1; soft sediment; MVS • 2 ♂♂, 1 ♀ (mounted for SEM); CRS 1702; 64°51.15′ S, 62°34.44′ W; 502 m b.s.l.; 30 Nov. 2015; FjordEco1; soft sediment; MVS • 1 ♂, 2 ♀♀ (mounted for SEM); CRS 1773; 64°52.35′ S, 62°25.88′ W; 553 m b.s.l.; 6 Apr. 2016; FjordEco2; soft sediment; MVS • 4 ♂♂, 1 ♀ (mounted for SEM); CRS 1790; 64°51.49′ S, 62°34.01′ W; 532 m b.s.l.; 10 Apr. 2016; FjordEco2; soft sediment; MVS • 1 ♂, 3 ♀♀ (mounted for SEM); CRS 1792; 64°51.40′ S, 62°34.01′ W; 525 m b.s.l.; 11 Apr. 2016; FjordEco2; soft sediment; MVS • 5 ♂♂, 1 ♀ (mounted for SEM); CRS 1793; 64°39.53′ S, 62°55.03′ W; 701 m b.s.l.; 11 Apr. 2016; FjordEco2; soft sediment; MVS • 1 ♀ (mounted for SEM); CRS 1799; 64°51.51′ S, 62°33.83′ W; 541 m b.s.l.; 13 Apr. 2016; FjordEco2; soft sediment; MVS • 5 ♂♂, 1 ♀ (mounted for SEM); CRS 1809; 64°39.59′ S, 62°55.09′ W; 694 m b.s.l.; 15 Apr. 2016; FjordEco2; soft sediment; MVS .</p><p>Description</p><p>GENERAL. Adults with head, neck, and eleven trunk segments (Figs 13A–B, 14A, 15A–B). An overview of measurements and dimensions is given in Table 11. Distributions of cuticular structures, i.e., sensory spots, glandular cell outlets, spines, and tubes, are summarized in Table 12.</p><p>HEAD. Consists of a retractable mouth cone and an introvert (Fig. 15C–D). Mouth cone with nine outer oral styles composed of two units; all oral styles with uniform morphology, but differ alternatingly in length, with styles in uneven numbered sectors being ca 15% longer than those in even numbered. Bases of outer oral styles with row of six slender spikes, flanked by pair of stronger spikes. A single fringe is located more basally, at the base of the mouth cone and in between the attachment points of the outer oral styles. Inner oral styles could not be examined.</p><p>INTROVERT. The arrangement of scalids follows the pattern of P. grzelakae nov. sp., thus see Fig. 6 for scalid arrangement. The introvert has ten primary spinoscalids in Ring 01. Each primary spinoscalid consists of a basal sheath and a distal end piece with a blunt tip (Fig. 15D). Rings 02 and 04 have 10 spinoscalids, and Rings 03 and 05 have 20. All spinoscalids in these rings are well-developed and consist of a basal sheath with fringed distal margins and a pointed end-piece. Ring 06 has only six spinoscalids, located in sectors 1, 3, 5, 6, 7, and 9; they resemble those in preceding sectors, but the distal end-pieces are slightly shorter. Ring 07 has eight scalids with very short end-pieces, i.e., shorter than the basal sheaths, located as pairs in sectors 1, 3, and 9, and as single, laterally displaced ones in sectors 5 and 7 (Fig. 6). Described sector-wise (Fig. 6), sectors 1, 3, and 9 are similar, having spinoscalids arranged as two double diamonds anterior to an additional pair of Ring 07 spinoscalids. Sectors 2, 4, 8, and 10 all have spinoscalids arranged as a quincunx, located in between an anterior spinoscalid in Ring 02 and a trichoscalid plate. Sectors 5 and 7 have spinoscalids forming double diamonds, anterior to an unpaired, lateral spinoscalid; the lateral spinoscalid is unpaired because a trichoscalid plate takes up the space on the opposite side of the sector. Sector 6 has its spinoscalids arranged as double diamonds. Regular trichoscalids with trichoscalid plates are present in sectors 2, 4, 5, 7, 8, and 10 (Figs 6, 15D).</p><p>NECK. With 16 placids. Midventral placid broadest, 13 µm in width and length, whereas all others are narrower, measuring 8 µm in width at their bases. The trichoscalid plates are well-developed and hat-shaped.</p><p>SEGMENT 1. Consists of a complete cuticular ring. Sensory spots are present in subdorsal, laterodorsal, and ventromedial positions; subdorsal and laterodorsal sensory spots are present on the anterior half of the segment, but not immediately at the anterior margin. They are composed of a dense tuft of micropapillae around a central pore and are flanked by three to five long, bristle-like cuticular hairs, arranged along the lower margin of the micropapillary area; ventromedial sensory spots are more posterior on the segment, with same appearance as the dorsal ones, but with only two or three cuticular hairs. Glandular cell outlets type 1 are present in middorsal and ventrolateral positions. Besides the few hairs around the sensory spots, the segment is completely devoid of cuticular hairs. The posterior segment margin is straight and terminates in a pectinate fringe with narrow and slender fringe tips (Figs 13A–B, 14B–C, 15E–G).</p><p>SEGMENT 2. Consists of a complete cuticular ring. Tubes are located in subdorsal, laterodorsal, sublateral, and ventrolateral positions; subdorsal tubes are located very close to the paradorsal positions. Sensory spots present in middorsal, midlateral, and ventromedial positions; the micropapillary areas around the sensory spots on this, and all following segments, are rounded. The micropapillae along the posterior margin of the areas are longer, and several conspicuously long micropapillae extend from the posterior part of the areas. Glandular cell outlets type 1 are present in middorsal and ventromedial positions. Bracteate cuticular hairs are arranged in three to four transverse rows; hairs in the two to three anteriormost rows are rather short, whereas those of the most posterior row are considerably longer, reaching the pectinate fringe at the posterior segment margin. The posterior segment margin is straight along the dorsal and lateral sides, but extends into a small midventral V-shaped flap. Pectinate fringe from middorsal to ventromedial areas with narrow and slender fringe tips as on preceding segment; however, from ventromedial to midsternal positions the fringe tips are conspicuously shorter and narrower (Figs 13A–B, 14B–C, 15E–G).</p><p>SEGMENT 3. As remaining segments, consisting of one tergal and two sternal plates. Sensory spots are present in subdorsal and sublateral positions, and glandular cell outlets type 1 in middorsal and ventromedial positions. The hair covering of the tergal and lateral halves of sternal plates is dense on the anterior half of the segment, except in hair-less midlateral areas; bracteate cuticular hairs are arranged in five to six rows; hairs in the two anteriormost rows are conspicuously short, only 1–2 µm; hairs in the median rows are longer, 5–6 µm, and hairs in the posteriormost row are very long, reaching the pectinate fringe. Paraventral areas without bracteate hairs, but with a rhomboid patch of fine, short hair-like extensions. Posterior segment margin straight and pectinate fringe as on preceding segment (Figs 13A–B, 14B–C, 15H, J).</p><p>SEGMENT 4. With spine in middorsal position. Sensory spots are not present. Glandular cell outlets type 1 are present in paradorsal and ventromedial positions. Cuticular hairs as on preceding segment, but in addition to the hairless midlateral areas, the middorsal area is also devoid of hairs. Posterior segment margin and pectinate fringe as on preceding segment (Figs 13A–B, 14B–C, 15H, J).</p><p>SEGMENT 5. With tubes in lateroventral positions. Sensory spots present in subdorsal, sublateral, and ventromedial positions, and glandular cell outlets type 1 in middorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 13A–B, 14B–C, 15I–J).</p><p>SEGMENT 6. With spines in middorsal and lateroventral positions. Sensory spots present in paradorsal, sublateral, and ventromedial positions. Glandular cell outlets type 1 present in paradorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 13A–B, 14B–C, 15I).</p><p>SEGMENT 7. With spines in lateroventral positions. Sensory spots present in paradorsal, sublateral, and ventromedial positions, and glandular cell outlets type 1 in middorsal and ventromedial positions. Cuticular hairs arranged in seven to eight rows, and still differentiated into very short, uniform hairs in the three to four anteriormost, longer hairs in the three median rows, and very long hairs in the posteriormost row. Posterior segment margin and pectinate fringe as on preceding segment (Figs 13A–B, 14D–E).</p><p>SEGMENT 8. With spines in middorsal and lateroventral positions, and tubes in sublateral positions. Sensory spots present in paradorsal positions only, and glandular cell outlets type 1 in paradorsal and ventromedial positions. Cuticular hairs as on preceding segment, but the midlateral hairless areas have moved to more laterodorsal positions. Posterior segment margin and pectinate fringe as on preceding segment (Figs 13A–B, 14D–F, 15L–M).</p><p>SEGMENT 9. With spines in lateroventral positions. Sensory spots present in paradorsal, laterodorsal, and ventrolateral positions. Very large glandular cell outlets type 2, with a broad rectangular flap projecting from the outlets, are present in laterodorsal positions. Glandular cell outlets type 1 present in paradorsal and ventromedial positions. Small rounded sieve plates located in lateral accessory positions, immediately next to the attachment point of the lateroventral spines. The cuticular hair covering is similar to that on the preceding segment, but hairless middorsal area is broader. Posterior segment margin and pectinate fringe as on preceding segment (Figs 13A–B, 14D–E, G–H, 15K–M).</p><p>SEGMENT 10. With sexually dimorphic laterodorsal tubes located near, but not at, the posterior segment margin; female tubes are extremely small, hardly projecting from attachment site; male tubes of more regular size, reaching beyond the segment margin. Males in addition with one to three flare-like setae extending from the secondary fringes of each sternal plate. Sensory spots present in subdorsal and ventrolateral positions. Glandular cell outlets type 1 present as two longitudinally arranged outlets in middorsal position and in ventromedial positions. Cuticular hairs with same size differentiation as on preceding segments, but only present from laterodorsal to ventromedial areas; middorsal and paradorsal areas with rhomboid patch of short, hair-like extensions. The posterior segment margin of the tergal plate is straight, with fringe tips as on preceding segments; however, the narrower ventromedial to midventral fringe tips are as long as the other fringe tips. Sternal plate margins straight, but slightly oblique (Figs 13A–D, 14I–K, 15N–P).</p><p>SEGMENT 11. With lateral terminal spines. Females with lateral terminal accessory spines; males with thin, tubular dorsal and ventral penile spines, and well-developed, cone-shaped medial pair of penile spines. Sensory spots present in paradorsal and ventromedial positions. Middorsal protuberance-like structure extends from intersegmentary joint. The segment is devoid of cuticular hairs, but has a dense covering of minute cuticular hair-like structures on the protuberance, in the paradorsal areas, and along the inferior margins of the tergal extensions. Tergal extensions are short and triangular, with a small denticle on the inferior margins. Sternal extensions short, broadly rounded, and not extending beyond tergal extensions (Figs 13 A–D, 14I–K, 15N–P).</p><p>Distribution</p><p>Antarctic Peninsula: Gerlache Strait and Andvord Bay MBA, IBB, and OBA, 499 to 701 m b.s.l. See Fig. 1 for geographic overview of stations and Table 1 for station and specimen information.</p><p>Diagnostic remarks</p><p>The new species can easily be assigned to Echinoderes, and when comparing the spine pattern combined with the presence of four pairs of tubes on segment 2, the number of similar congeners is narrowed down to two described species, E. hakaiensis Herranz et al., 2018 and E. frodoi Grzelak &amp; Sørensen, 2022, and the undescribed Echinoderes sp. 3, reported from abyssal plains near the Atacama Trench by Grzelak et al. (2021). However, E. nataliae sp. nov. can be distinguished from E. hakaiensis and Echinoderes sp. 3 by the presence of large glandular cell outlets type 2 on segment 9. Glandular cell outlets type 2 are not present at all in E. hakaiensis or Echinoderes sp. 3 (Herranz et al. 2018; Grzelak et al. 2021).</p><p>The glandular cell outlets type 2 on segment 9 in E. nataliae sp. nov. are not only large. They also have a very particular morphology, with a rectangular flap projecting from the openings. Somewhat similar structures are present in E. frodoi, even though Grzelak &amp; Sørensen (2022) reported the structures as “laterodorsal tubes”. Echinoderes frodoi has large openings, resembling glandular cell outlets type 2, in lateral accessory positions on segment 8 and in laterodorsal positions on segment 9. On both segments, there are flattened, tubular structures projecting from the openings. The structures look like collapsed tubes and were interpreted as such by Grzelak &amp; Sørensen (2022), but they could in fact also be flattened flaps, as seen on segment 9 in E. nataliae . Although the structures in the two species are very similar, they are not identical. For instance, the flaps in E. nataliae are rectangular, close to quadratic (Fig. 15K), whereas they are clearly more elongate and slender in E. frodoi – at least on segment 8. On segment 9 in E. frodoi, the tubes vary between forming short but wide collars to forming elongate but yet rather wide tubes. We believe that the two species share a special and homologous variation of type 2 glandular cell outlets.</p><p>Besides the similar glandular cell outlets, and resemblance in tube and spine patterns, E. frodoi and E. nataliae sp. nov. also differ on several points. The most substantial difference between the two species is the midlateral tubes on segment 1, present in E. frodoi only. However, these tubes are not consistently present in all specimens of E. frodoi, and even though such tubes never occurred in the 50+ examined specimens of E. nataliae, their inconsistent occurrence in E. frodoi makes them less useful as a differential character. Another difference between the two species is expressed in their morphometrics. The trunk length of E. frodoi ranges from 161 to 202 µm, unlike the 240 to 312 µm in E. nataliae, and the general trunk shape of E. frodoi appears stouter or chubbier than the more slender E. nataliae . This difference is expressed in the differing Maximum Sternal Width to Trunk Length ratios, with an average of 24.7% in E. frodoi (Grzelak &amp; Sørensen 2022) but only 19.7% in E. nataliae . Also all middorsal spines are longer in E. nataliae, and the ranges of the middorsal spine lengths in the two species never overlap. Small differences are also expressed in the position of tubes on segment 8, with the tubes of E. frodoi attaching in lateral accessory positions, whereas they are more dorsal in E. nataliae and sit in sublateral positions. There are also distinct differences in the cuticular hair covering of the two species. Echinoderes nataliae never has cuticular hairs on segment 1 (except those associated with the sensory spots), but has a relatively dense hair covering on the following nine segments. In contrast, most specimens of E. frodoi have plenty of hairs on segment 1, whereas the hair covering of the remaining segments is less dense compared to that of E. nataliae . Finally, E. nataliae has a pair of large and distinct ventromedial sensory spots on segment 1. Such sensory spots are lacking in E. frodoi . Thus, in conclusion, E. nataliae and E. frodoi are clearly two very similar species, and very likely also closely related, but they are also easily distinguished by several conspicuous as well as more subtle differences.</p><p>The distribution of glandular cell outlets type 1 in E. nataliae sp. nov. follows the MD Seg. 1–3, 5, 7, PD 4, 6, 8–9 pattern (see table with summary of species with this pattern described up to 2020 in Sørensen et al. 2020).</p></div>	https://treatment.plazi.org/id/03AE4066FF97D47D1768FED7FE1FFA98	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Sørensen, Martin V.;Macheriotou, Lara;Braeckman, Ulrike;Smith, Craig R.;Ingels, Jeroen	Sørensen, Martin V., Macheriotou, Lara, Braeckman, Ulrike, Smith, Craig R., Ingels, Jeroen (2025): Antarctic Kinorhyncha: Seven new species from the Antarctic Peninsula. European Journal of Taxonomy 1000 (1): 1-102, DOI: 10.5852/ejt.2025.1000.2947, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2947/13307
03AE4066FF8FD476173BFA6FFBD1FCF5.text	03AE4066FF8FD476173BFA6FFBD1FCF5.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Echinoderes kathleenhannae Sørensen & Macheriotou & Braeckman & Smith & Ingels 2025	<div><p>Echinoderes kathleenhannae sp. nov.</p><p>urn:lsid:zoobank.org:act: DD7B8B21-DE35-47FC-98F7-B0A8F3832421</p><p>Figs 16–18, Tables 13–14</p><p>Diagnosis</p><p>Echinoderes with acicular spines in middorsal position on segments 4, 6, and 8, and in lateroventral positions on segments 6 to 9. Tubes present in subdorsal, laterodorsal, sublateral, and ventrolateral positions on segment 2, in lateroventral positions on segment 5, in laterodorsal and lateral accessory positions on segment 8, and in laterodorsal positions on segment 10; tubes on segment 10 show sexual dimorphism and are largest in males. Female papillae or glandular cell outlets type 2 not present. Dorsal glandular cell outlets type 1 are present in middorsal positions on segments 1 to 3, 5, 7, and 10, and in paradorsal positions on segments 4, 6, 8, and 9. Sieve plates present on segment 9 in sublateral positions.</p><p>Etymology</p><p>The species is dedicated to the musician, artist, activist and rebel girl, Kathleen Hanna.</p><p>Material examined</p><p>Holotype ANTARCTICA • ♂ (mounted for LM in Fluoromount G on HS slide); Antarctic Peninsula, CRS 1793; 64°39.53′ S, 62°55.03′ W; 701 m b.s.l.; 11 Apr. 2016; FjordEco2; soft sediment; NHMD 1786779.</p><p>Additional material</p><p>ANTARCTICA • 1 ♀ (mounted for SEM); same data as for holotype; MVS • 3 ♂♂, 1 ♀ (mounted for SEM); Antarctic Peninsula, CRS 1832; 64°39.30′ S, 62°55.98′ W; 631 m b.s.l.; 21 Apr. 2016; FjordEco2; soft sediment; MVS .</p><p>Description</p><p>GENERAL. Adults with head, neck and eleven trunk segments (Figs 16A–B, 17A, 18A–C). An overview of measurements and dimensions is given in Table 13. Distributions of cuticular structures, i.e., sensory spots, glandular cell outlets, spines and tubes, are summarized in Table 14.</p><p>HEAD. All specimens had their heads fully retracted; thus, information on head morphology is not available.</p><p>NECK. With 16 placids. Midventral placid broadest, 12 µm in width and 13 µm in length, whereas all others are narrower, measuring 8 µm in width at their bases. The trichoscalid plates are well-developed and hat-shaped.</p><p>SEGMENT 1. Consists of a complete cuticular ring. Sensory spots are present in subdorsal and laterodorsal positions; the sensory spots are small, with numerous micropapillae and two long cuticular hairs attached on the margin of the papillated area. Glandular cell outlets type 1 are present in middorsal and ventrolateral positions. Cuticular hairs emerge from rounded perforation sites and are arranged in four to five rows on the dorsal side, and only two to three rows on the ventral. The posterior segment margin is almost straight and terminates in a pectinate fringe with rather broad fringe tips (Figs 16A–B, 17B–C, 18D–F).</p><p>SEGMENT 2. Consists of a complete cuticular ring. Tubes are located in subdorsal, laterodorsal, sublateral, and ventrolateral positions; all tubes are very slender, and the proximal thickenings are hardly visible. Sensory spots present in middorsal, laterodorsal, and ventromedial positions; the micropapillary areas around the sensory spots on this, and all following segments, are rounded, with up to five longer micropapillae extending from the posterior part of the papillated areas. Glandular cell outlets type 1 are present in middorsal and ventromedial positions. Bracteate cuticular hairs are arranged in three to four transverse rows; hairs in the first and second anterior rows are rather short, whereas those of the most posterior row are longer. The posterior segment margin is nearly straight. Pectinate fringe of dorsal and lateral margins well-developed, as on preceding segment; pectinate fringe of ventrolateral to midventral margins narrower and with extended, flexible tips (Figs 16A–B, 17B–C, 18D–F).</p><p>SEGMENT 3. As remaining segments, consisting of one tergal and two sternal plates. Sensory spots are present in subdorsal and sublateral positions, and glandular cell outlets type 1 in middorsal and ventromedial positions. The hair covering of the tergal and lateral halves of sternal plates is dense on the anterior half of the segment, except in hair-less midlateral areas; bracteate cuticular hairs are arranged in five to six rows, and the hairs in each row get progressively longer towards the more posterior rows. Paraventral areas without bracteate hairs, but with rhomboid patch of well-developed hair-like extensions. Posterior segment margin straight, and pectinate fringe as on preceding segment (Figs 16A–B, 17B–C).</p><p>SEGMENT 4. With spine in middorsal position; middorsal spines on this and segments 6 and 8 are uniform in length, rather than getting progressively longer towards the more posterior segments. Sensory spots are not present. Glandular cell outlets type 1 are present in paradorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 16A–B, 17D–E).</p><p>SEGMENT 5. With tubes in lateroventral positions. Sensory spots present in subdorsal, midlateral and ventromedial positions, and glandular cell outlets type 1 in middorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 16A–B, 17D–E, 18G–I).</p><p>SEGMENT 6. With spines in middorsal and lateroventral positions; lateroventral spines on this and following segments are almost uniform in length, rather than getting progressively longer towards the more posterior segments. Sensory spots present in paradorsal, midlateral and ventromedial positions, and glandular cell outlets type 1 in paradorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 16A–B, 17D–E, 18G–I).</p><p>SEGMENT 7. With spines in lateroventral positions. Sensory spots present in subdorsal, midlateral, and ventromedial positions, and glandular cell outlets type 1 in middorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 16A–B, 17F–G, 18L).</p><p>SEGMENT 8. With spines in middorsal and lateroventral positions, and tubes in laterodorsal and lateral accessory positions. Sensory spots present in paradorsal positions only, and glandular cell outlets type 1 in paradorsal and ventromedial positions. Cuticular hairs as on preceding segment, except for mid- and paradorsal areas, where the bracteate hairs are replaced by very fine hair-like extensions. Posterior segment margin and pectinate fringe as on preceding segment (Figs 16A–B, 17F–J, 18J–L).</p><p>SEGMENT 9. With spines in lateroventral positions. Sensory spots present in paradorsal, subdorsal, laterodorsal, and ventrolateral positions. Glandular cell outlets type 1 present in paradorsal and ventromedial positions. Small rounded sieve plates present in sublateral positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 16A–B, 17H–K, 18J–K).</p><p>SEGMENT 10. With sexually dimorphic laterodorsal tubes; male tubes well-developed, located near, but not at, the posterior segment margin; female tubes shorter and attaching at the posterior segment margin. Sensory spots present in subdorsal and ventrolateral positions. Glandular cell outlet type 1 present as two longitudinally arranged outlets in middorsal position, and in ventromedial positions. Cuticular hairs in two to three rows and only present from laterodorsal to ventromedial areas; middorsal and paradorsal areas with rhomboid patch of short, hair-like extensions. The posterior segment margin of the tergal plate is straight, with fringe tips as on preceding segments. Sternal plate margins oblique towards posteriormost midventral point; fringe tips well-developed, like those along the dorsal margin (Figs 16A–D, 17J–M, 18M–O).</p><p>SEGMENT 11. With lateral terminal spines. Females with lateral terminal accessory spines, measuring around 42 µm (measure estimated from SEM images); males with thin, tubular dorsal and ventral penile spines; medial pair of penile spines cone-shaped and well-developed. Sensory spots present in ventromedial positions. Middorsal protuberance-like structure extends from intersegmentary joint. The segment is devoid of cuticular hairs, but has a dense covering of minute, cuticular hair-like structures on the middorsal protuberance, in the paradorsal areas, and along the inferior margins of the tergal extensions. Tergal extensions are short and triangular with a small denticle on the inferior margins. Sternal extensions short, broadly rounded, and not extending beyond tergal extensions (Figs 16A–D, 17L–M, 18M–O).</p><p>Distribution</p><p>Antarctic Peninsula: Gerlache Strait, 631 to 701 m b.s.l. See Fig. 1 for geographic overview of stations and Table 1 for station and specimen information.</p><p>Diagnostic remarks</p><p>The new species clearly belongs to Echinoderes, and the presence of laterodorsal and lateral accessory tubes on segment 8 but otherwise absence of tubes on segments 6 and 7 makes the species unique among congeners. Only five species of Echinoderes have the combined presence of laterodorsal and lateral accessory tubes on segment 8, i.e., E. abbreviatus Higgins, 1983, E. belenae Pardos et al., 2016b, E. brevipes Cepeda et al., 2019b, E. rociae Pardos et al., 2016a, and E. intermedius Sørensen, 2006 (Higgins 1983; Sørensen 2006; Pardos et al. 2016a, 2016b; Cepeda et al. 2019b). However, the four first mentioned species all have short and stout lateral terminal spines, which makes them very easy to distinguish from E. kathleenhannae sp. nov. Only E. intermedius show some resemblance with the new species, but the presence of midlateral glandular cell outlets type 2 on segment 2 and of lateral accessory tubes on segments 6 and 7 still makes it differ considerably from the new species.</p><p>Another species that could be confused with E. kathleenhannae sp. nov. is E. hispanicus . The two species share the same general habitus and spine pattern, and E. hispanicus also has two sets of tubes on segment 8. In E. hispanicus the tubes are located in midlateral and lateral accessory positions (Pardos et al. 1998), which differs slightly from the laterodorsal and lateral accessory tube positions in E. kathleenhannae . However, especially on the more posterior segments, the laterodorsal and midlateral positions are so close to each other that they can be difficult to distinguish; thus, the tube positions on segment 8 are not in themselves suitable for species differentiation. The easy way to distinguish the two species is by the number of tubes on segment 2, where E. kathleenhannae has four pairs, whereas E. hispanicus lacks the laterodorsal tubes and therefore has only three pairs of tubes.</p><p>The distribution of glandular cell outlets type 1 in E. kathleenhannae sp. nov. follows the MD Seg. 1–3, 5, 7, PD 4, 6, 8–9 pattern, as is the case with the two congeners described above.</p></div>	https://treatment.plazi.org/id/03AE4066FF8FD476173BFA6FFBD1FCF5	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Sørensen, Martin V.;Macheriotou, Lara;Braeckman, Ulrike;Smith, Craig R.;Ingels, Jeroen	Sørensen, Martin V., Macheriotou, Lara, Braeckman, Ulrike, Smith, Craig R., Ingels, Jeroen (2025): Antarctic Kinorhyncha: Seven new species from the Antarctic Peninsula. European Journal of Taxonomy 1000 (1): 1-102, DOI: 10.5852/ejt.2025.1000.2947, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2947/13307
03AE4066FF84D40F1755FC9CFB87F878.text	03AE4066FF84D40F1755FC9CFB87F878.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Echinoderes antarcticus Sørensen & Macheriotou & Braeckman & Smith & Ingels 2025	<div><p>Echinoderes antarcticus sp. nov.</p><p>urn:lsid:zoobank.org:act: 940A9763-763D-4DBE-9A81-66F7A97312B8</p><p>Figs 19–21, Tables 15–16</p><p>Diagnosis</p><p>Echinoderes with acicular spines in middorsal position on segments 4, 6, and 8, and in lateroventral positions on segments 6 to 9. Tubes present in subdorsal, sublateral, and ventrolateral positions on segment 2, in lateroventral positions on segment 5, in sublateral positions on segment 8, and in laterodorsal positions on segment 10. Terminal segment with middorsal fissure, splitting the tergal plate in two. Male morphology unknown. Female papillae or glandular cell outlets type 2 not present. Dorsal glandular cell outlets type 1 are present in middorsal positions on segments 1 to 3, 5, 7 and 10, and in paradorsal positions on segments 4, 6, 8, and 9. Sieve plates present on segment 9 in lateral accessory positions.</p><p>Etymology</p><p>The species name ‘ antarcticus ’ is derived from the Greek ανταρκτικός (antarcticos), meaning ‘opposite to north’ (masculine).</p><p>Material examined</p><p>Holotype ANTARCTICA • ♀ (mounted for LM in Fluoromount G on HS slide); Antarctic Peninsula, CRS 1778; 64°47.01′ S, 62°43.90′ W; 567 m b.s.l.; 8 Apr. 2016; FjordEco2; soft sediment; NHMD 1786932.</p><p>Paratype</p><p>ANTARCTICA • 1 ♀ (mounted as holotype); Antarctic Peninsula, CRS 1809; 64°39.59′ S, 62°55.09′ W; 694 m b.s.l.; 15 Apr. 2016; FjordEco2; soft sediment; USNM 1740040 .</p><p>Additional material</p><p>ANTARCTICA • 1 ♀ (mounted for SEM); Antarctic Peninsula, CRS 1832; 64°39.30′ S, 62°55.98′ W; 631 m b.s.l.; 21 Apr. 2016; FjordEco2; soft sediment; MVS .</p><p>Description</p><p>GENERAL. Adults with head, neck and eleven trunk segments (Figs 19A–B, 20A, 21A–B). The trunk is nearly parallel-sided from segment 2 to 7, and the cuticle of a thickness that makes all cuticular structures appear very distinct. An overview of measurements and dimensions is given in Table 15. Distributions of cuticular structures, i.e., sensory spots, glandular cell outlets, spines and tubes, are summarized in Table 16.</p><p>HEAD. The available SEM specimen and the paratype had their heads fully retracted, whereas the head of the holotype was only partly extended; thus, information on head morphology is very limited. The presence of nine outer oral styles, each composed of two units, is evident though. The neck consists of 16 placids. Midventral placid broadest, 14 µm in width and 16 µm in length, whereas all others are narrower, measuring 9 µm in width at their bases. The trichoscalid plates are well-developed and hat-shaped.</p><p>SEGMENT 1. Consists of a complete cuticular ring. Sensory spots are present in subdorsal, laterodorsal, and ventromedial positions; the sensory spots are rounded to droplet-shaped, with numerous micropapillae around a central pore. Glandular cell outlets type 1 are present in middorsal and lateroventral positions. Cuticular hairs emerge from rounded perforation sites and are arranged in three diffuse rows on the dorsal side, a single row in the sublateral positions, and two rows ventrally, between the sensory spots. The posterior segment margin is almost straight and terminates in a pectinate fringe with tripartite tips (Figs 19A–B, 20B–C, 21C–D).</p><p>SEGMENT 2. Consists of a complete cuticular ring. Tubes are located in subdorsal, sublateral, and ventrolateral positions; all tubes are very slender, and the proximal thickenings are hardly visible. Sensory spots present in middorsal, midlateral, and ventromedial positions; the micropapillary areas around the sensory spots on this, and all following segments, are rounded, with up to five longer micropapillae extending from the posterior part of the papillated areas. Glandular cell outlets type 1 are present in middorsal and ventromedial positions. Bracteate cuticular hairs are arranged in five transverse rows; hairs in the first anterior row are short, whereas those of the more posterior rows are considerably longer. The posterior segment margin is nearly straight, except at the small, midventral V-shaped extension. Pectinate fringe with well-developed, pointed fringe tips along dorsal and lateral margins; ventromedial fringe tips similar, but shorter and narrower (Figs 19A–B, 20B–C, 21C–D).</p><p>SEGMENT 3. As following seven segments, consisting of one tergal and two sternal plates. Sensory spots are present in subdorsal and sublateral positions, and glandular cell outlets type 1 in middorsal and ventromedial positions. The hair covering of the tergal and lateral halves of sternal plates is dense on the anterior half of the segment, except in hair-less midlateral areas, with bracteate cuticular hairs as on preceding segment. Paraventral areas without bracteate hairs, but with shield-shaped patch of well-developed hair-like extensions. Posterior segment margin straight, and pectinate fringe as on preceding segment (Figs 19A–B, 20B–C).</p><p>SEGMENT 4. With spine in middorsal position. Sensory spots are not present. Glandular cell outlets type 1 are present in paradorsal and ventromedial positions. Cuticular hairs from paradorsal to ventromedial positions arranged in seven to eight rows, with very short hairs in the anteriormost row, and hairs of remaining rows getting progressively longer towards the more posterior rows; middorsal area with triangular patch of short, hair-like extensions; paraventral areas as on preceding segment. Segment margin and pectinate fringe as on preceding segment (Figs 19A–B, 20B–C, 21E).</p><p>SEGMENT 5. With tubes in lateroventral positions. Sensory spots present in subdorsal, sublateral and ventromedial positions, and glandular cell outlets type 1 in middorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 19A–B, 20D–E, 21E–G).</p><p>SEGMENT 6. With spines in middorsal and lateroventral positions. Sensory spots present in paradorsal, sublateral and ventromedial positions, and glandular cell outlets type 1 in paradorsal and ventromedial positions. Cuticular hairs as on preceding segment, except for the dorsal patch of hair-like extensions that covers both the middorsal and paradorsal areas. Posterior segment margin and pectinate fringe as on preceding segment (Figs 19A–B, 20D–E, 21E–G).</p><p>SEGMENT 7. With spines in lateroventral positions. Sensory spots present in paradorsal, sublateral, and ventromedial positions, and glandular cell outlets type 1 in middorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 19A–B, 20D–E, 21G, I).</p><p>SEGMENT 8. With spines in middorsal and lateroventral positions, and tubes in sublateral positions. Sensory spots present in paradorsal positions only, and glandular cell outlets type 1 in paradorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 19A–B, 20F–H, 21I).</p><p>SEGMENT 9. With spines in lateroventral positions. Sensory spots present in paradorsal, subdorsal, laterodorsal, and ventrolateral positions. Glandular cell outlets type 1 present in paradorsal and ventromedial positions. Small rounded sieve plates present in lateral accessory positions. Cuticular hairs as on preceding segment, but with midlateral hairless areas in more laterodorsal positions and dorsal area of hair-like extensions even broader, extending into the subdorsal areas. Posterior segment margin and pectinate fringe as on preceding segment (Figs 19A–B, 20J–K, 21H).</p><p>SEGMENT 10. With short laterodorsal tubes of females attaching at the posterior segment margin. Potential sexual dimorphism in length of these laterodorsal tubes unknown. Sensory spots present in subdorsal and ventrolateral positions. Glandular cell outlet type 1 present as two longitudinally arranged outlets in middorsal position, and in ventromedial positions. Cuticular hairs in three rows and only present from laterodorsal to ventromedial areas; middorsal to subdorsal areas with patch of short, hair-like extensions. The posterior segment margin of the tergal plate is straight, whereas sternal plate margins are deeply concave; all fringe tips along the margins are narrow and slender (Figs 19A–B, 20J–K, 21H, J).</p><p>SEGMENT 11. Consisting of two tergal and two sternal plates. Lateral terminal and lateral terminal accessory (the latter assumed female dimorphic) spines present. Sensory spots not observed. The segment is devoid of cuticular hairs, but has a dense covering of minute cuticular hair-like structures, only interrupted by smooth areas laterodorsally and lateroventral to ventromedially. Tergal extensions are triangular, and sternal extensions rounded, with deeply fringed margins (Figs 19A–B, 20I–K, 21H, J).</p><p>Distribution</p><p>Antarctic Peninsula: Gerlache Strait and Andvord Bay OBA, 567 to 694 m b.s.l. See Fig. 1 for geographic overview of stations and Table 1 for station and specimen information.</p><p>Diagnostic remarks</p><p>The new species can easily be assigned to Echinoderes based on the composition of its trunk segments. The middorsal fissure that divides the tergal plate of segment 11 into two halves is not common in the genus, but it does occur in various species, such as E. beringiensis, E. cernunnos Sørensen et al., 2012, E. drogoni Grzelak &amp; Sørensen, 2018, E. galadrielae Grzelak &amp; Sørensen, 2022, the recently described species E. quasae Herranz et al., 2024 (Sørensen et al. 2012; Grzelak &amp; Sørensen 2018, 2022; Adrianov &amp; Maiorova 2022; Herranz et al. 2024), and in E. angustus as discussed below under Echinoderes aff. angustus . Besides the divided tergal plate, the four species do not share any particular similarities.</p><p>The character that most easily distinguishes the new species is the configuration of tubes on segment 2. Tubes on segment 2 are quite common among species of Echinoderes, but the presence of tubes in subdorsal, sublateral, and ventrolateral positions, and not in laterodorsal positions as well, is only shared between six species (Yamasaki et al. 2020b). Among these, just four species have middorsal spines on segments 4, 6 and 8 only. The four species in question are E. belenae, E. hispanicus, E. peterseni Higgins &amp; Kristensen, 1988, and E. xiphophorus Adrianov &amp; Maiorova, 2021 . Among these species, E. belenae differs the most, with its short and stout lateral terminal spines and numerous tubes distributed over most trunk segments (Pardos et al. 2016b). Also E. hispanicus is easily distinguished from the new species by having both sublateral and lateral accessory tubes on segment 8 (Pardos et al. 1998) and E. xiphophorus by its long and slender tergal extensions (Adrianov &amp; Maiorova 2021).</p><p>Interestingly, the species showing the closest resemblance to E. antarcticus sp. nov. is the Arctic species E. peterseni, known from West Greenland, NE Canada, and Svalbard (Higgins &amp; Kristensen 1988; Sørensen &amp; Kristensen 2000; Grzelak &amp; Sørensen 2018). The two antipodean species basically share the same spine/tube distribution patterns, with the tube positions on segment 8 as the only minor difference. In E. antarcticus, the tubes are sublateral, whereas they are lateral accessory in E. peterseni, but this in itself is not sufficient to distinguish the two species. The easiest way to tell the species apart is morphometrically, where E. antarcticus generally is larger than E. peterseni . The trunk lengths of the two E. antarcticus types are 318 µm and 377 µm, whereas trunk lengths of E. peterseni, as reported by Higgins &amp; Kristensen (1988), range between 250 µm and 325 µm. Likewise, the middorsal spines are longer in E. antarcticus, i.e., on segment 4: 48–55 µm vs 30–44 µm; on segment 6: 78–79 µm vs 45–60 µm; on segment 8: 92–105 µm vs 60–70 µm. Regarding cuticular structures, the sensory spot distribution patterns differ slightly between the two species, i.e., E. antarcticus has paradorsal sensory spots on segment 7, whereas these sensory spots in E. peterseni clearly sit in subdorsal positions (see Grzelak &amp; Sørensen 2018: fig. 18f). Furthermore, E. antarcticus has three pairs of tergal sensory spots on segment 9, in paradorsal, subdorsal, and laterodorsal positions, whereas E. peterseni has only two pairs, in paradorsal and laterodorsal positions. Finally, the cuticular hair covering is generally denser in E. antarcticus, typically with hairs in seven to eight rows, as opposed to only five rows in E. peterseni, and the latter species also lacks patches of hair-like extensions in middorsal and paraventral positions, instead having regular bracteate hairs.</p><p>Thus, with help from these relatively subtle characters, it is possible to distinguish the two species. It is, however, still striking to observe two species with an antipodean distribution being so similar and putatively closely related. This clearly suggests that kinorhynch relationships are not always reflected in their biogeography.</p><p>The distribution of glandular cell outlets type 1 in E. antarcticus sp. nov. follows the MD Seg. 1–3, 5, 7, PD 4, 6, 8–9 pattern, as is the case with the all congeners described above.</p></div>	https://treatment.plazi.org/id/03AE4066FF84D40F1755FC9CFB87F878	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Sørensen, Martin V.;Macheriotou, Lara;Braeckman, Ulrike;Smith, Craig R.;Ingels, Jeroen	Sørensen, Martin V., Macheriotou, Lara, Braeckman, Ulrike, Smith, Craig R., Ingels, Jeroen (2025): Antarctic Kinorhyncha: Seven new species from the Antarctic Peninsula. European Journal of Taxonomy 1000 (1): 1-102, DOI: 10.5852/ejt.2025.1000.2947, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2947/13307
03AE4066FFFCD407177DFED7FAE0FB95.text	03AE4066FFFCD407177DFED7FAE0FB95.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Echinoderes crux Sørensen & Macheriotou & Braeckman & Smith & Ingels 2025	<div><p>Echinoderes crux sp. nov.</p><p>urn:lsid:zoobank.org:act: 7F3ECD36-A974-404A-9476-D1A3435F29D3</p><p>Figs 22–24, Tables 17–18</p><p>Diagnosis</p><p>Echinoderes with acicular spines in middorsal position on segments 4, 6, and 8, and in lateroventral positions on segments 6 to 9. Tubes present in lateroventral positions on segment 5. Minute slit-like openings (glandular cell outlets type 2?) present near the anterior margin of segment 1 in subdorsal (two pairs), laterodorsal, sublateral, and ventromedial positions. Numerous glandular cell outlets type 2 are present throughout segments 2 to 9: paradorsal positions on segment 3; subdorsal positions on segments 2 to 9 (two pairs on segments 2 and 9); laterodorsal positions on segments 2 to 9 (two pairs on segment 2); sublateral positions on segments 2 to 3 and 5 to 9 (two pairs on segments 2 and 8); lateral accessory positions on segments 3 and 5 to 7; lateroventral positions on segment 4; and ventrolateral positions on segment 2. Dorsal glandular cell outlets type 1 are present at least in middorsal positions on segments 1, 3, 5, 7, and 10, and in paradorsal positions on segments 4, 6, 8, and 9. Female papillae not present; male morphology unknown. Sieve plates present on segment 9 in lateral accessory positions.</p><p>Etymology</p><p>The species is named ‘ crux ’, after the constellation Crux, also known as the Southern Cross.</p><p>Material examined</p><p>Holotype ANTARCTICA • ♀ (mounted for SEM); Antarctic Peninsula, CRS 1760; 64°47.86′ S, 65°21.09′ W; 593 m b.s.l.; 21 Dec. 2015; FjordEco1; soft sediment; NHMD 1790632.</p><p>Paratype</p><p>ANTARCTICA • 1 ♀ (mounted for SEM); same data as for holotype; NHMD 1790633 .</p><p>Description</p><p>GENERAL. Adults with head, neck and eleven trunk segments (Figs 22A–B, 23A–C). The species is characterised by numerous series of minute glandular cell outlets type 2. An overview of measurements and dimensions estimated from SEM is given in Table 17. Distributions of cuticular structures, i.e., sensory spots, glandular cell outlets, spines, and tubes, are summarized in Table 18.</p><p>HEAD. The two available specimens both had their heads fully retracted; thus, information on head morphology is not available.</p><p>NECK. Consists of 16 placids. Midventral placid broadest, 9 µm in width and 10 µm in length, whereas all others are narrower, measuring 6 µm in width at their bases. The trichoscalid plates are well-developed and hat-shaped.</p><p>SEGMENT 1. Consists of a complete cuticular ring. Sensory spots are present in subdorsal and laterodorsal positions; the sensory spots are large, rounded, with numerous micropapillae around two pores; seven to eight long cuticular hairs emerge from the margin of the micropapillary area. ‘Slit-like openings’ are located near the anterior segment margin in subdorsal (two pairs), laterodorsal, sublateral and ventromedial positions; the openings are perfectly round rather than slit-like, but the term ‘slit-like openings’ is chosen to stress their clear homology with the corresponding structures in Echinoderes aragorni Grzelak &amp; Sørensen, 2022 . Glandular cell outlets type 1 are present in middorsal and lateroventral positions. Besides the cuticular hairs around the margins of the sensory spots, the segment is completely devoid of hairs. The posterior segment margin is straight along the dorsal and lateral sides, but has a broadly rounded ventral extension. The fringe tips are long and have a broader basis that narrows abruptly into a slender distal tip (Figs 22A–B, 23D–F).</p><p>SEGMENT 2. Consists of a complete cuticular ring. Glandular cell outlets type 2 are present in subdorsal (two pairs), laterodorsal (two pairs), sublateral (two pairs), and ventrolateral (one pair) positions; the outlets, on this and following segments, are minute (&gt; 1 µm in diameter) and have a collar of fringes projecting from the openings. Sensory spots present in middorsal, laterodorsal, and ventromedial positions; the micropapillary areas around the sensory spots on this, and all following segments, are rounded, and longer micropapillae extend from the posterior part of the papillated areas. Glandular cell outlets type 1 are present in ventromedial positions; the most anterior part of the middorsal line could not be examined in any of the specimens; thus, type 1 outlets could potentially be present there as well. Bracteate cuticular hairs are arranged in three transverse rows; hairs in the first anterior row are short, whereas those of the more posterior rows are fairly long. The posterior segment margin is almost straight. Pectinate fringe with well-developed, long, triangular fringe tips along all margins (Figs 22A–B, 23D–F).</p><p>SEGMENT 3. As following seven segments, consisting of one tergal and two sternal plates. Glandular cell outlets type 2 are present in paradorsal, subdorsal, laterodorsal, sublateral, and lateral accessory positions. Sensory spots are present in subdorsal and sublateral positions, and glandular cell outlets type 1 in middorsal and ventromedial positions. The hair covering of the tergal and lateral halves of sternal plates is dense on the anterior half of the segment, except in hair-less midlateral areas, with bracteate cuticular hairs as on preceding segment. Paraventral areas without bracteate hairs, but with shield-shaped patch of well-developed hair-like extensions. Posterior segment margin straight and pectinate fringe as on preceding segment (Figs 22A–B, 23G–I).</p><p>SEGMENT 4. With spine in middorsal position. Glandular cell outlets type 2 are present in subdorsal, laterodorsal, and lateroventral positions. Sensory spots are not present. Glandular cell outlets type 1 are present in paradorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 22A–B, 23G–I).</p><p>SEGMENT 5. With tubes in lateroventral positions. Glandular cell outlets type 2 are present in subdorsal, laterodorsal, sublateral, and lateral accessory positions. Sensory spots present in subdorsal, sublateral, and ventromedial positions, and glandular cell outlets type 1 in middorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 22A–B, 24A–C).</p><p>SEGMENT 6. With spines in middorsal and lateroventral positions. Glandular cell outlets type 2 as on preceding segment. Sensory spots present in paradorsal, sublateral, and ventromedial positions, and glandular cell outlets type 1 in paradorsal and ventromedial positions. Cuticular hairs as on preceding segment, but arranged in additional rows; middorsal area without hairs. Posterior segment margin and pectinate fringe as on preceding segment (Figs 22A–B, 24A–C).</p><p>SEGMENT 7. With spines in lateroventral positions. Glandular cell outlets type 2 and sensory spots as on preceding segment. Glandular cell outlets type 1 present in middorsal and ventromedial positions. Cuticular hairs as on proceeding segment, but with middorsal hairless areas now also reaching the paradorsal positions. Posterior segment margin and pectinate fringe as on preceding segment (Figs 22A–B, 24D–F).</p><p>SEGMENT 8. With spines in middorsal and lateroventral positions. Glandular cell outlets type 2 are present in subdorsal, laterodorsal, and sublateral (two pairs) positions. Sensory spots present in paradorsal positions only, and glandular cell outlets type 1 in paradorsal and ventromedial positions. Cuticular hairs as on preceding segment, but hairless dorsal area also reaches into the subdorsal positions and has a covering of hair-like extensions. Posterior segment margin and pectinate fringe as on preceding segment (Figs 22A–B, 24F–H).</p><p>SEGMENT 9. With spines in lateroventral positions. Glandular cell outlets type 2 are present in subdorsal (two pairs), laterodorsal, and sublateral positions. Sensory spots present in paradorsal, subdorsal, laterodorsal, and ventrolateral positions. Glandular cell outlets type 1 present in paradorsal and ventromedial positions. Very minute sieve plates present in lateral accessory positions, at base of spine. Cuticular hairs as on preceding segment, but with midlateral hairless areas in more laterodorsal positions and dorsal area of hair-like extensions even broader, extending well into the subdorsal areas. Posterior segment margin and pectinate fringe as on preceding segment (Figs 22A–B, 24I–L).</p><p>SEGMENT 10. Without spines, tubes, or glandular cell outlets type 2. Male morphology, and thus potential presence of tubes, is so far unknown. Sensory spots present in subdorsal and ventrolateral positions. Glandular cell outlet type 1 present as a single outlet in middorsal position and as a pair in ventromedial positions. Cuticular hairs in three rows and only present from laterodorsal to ventromedial areas; middorsal to subdorsal areas with patch of short, hair-like extensions between the sensory spots and as a distinct, oblique row below the laterodorsal cuticular hairs; paralateral areas without any kind of hairs or hair-like extensions. The posterior segment margin of the tergal plate is straight, whereas sternal plate margins are deeply concave; all fringe tips along the margins are narrow and slender (Figs 22A–B, 24L–O).</p><p>SEGMENT 11. With lateral terminal- and lateral terminal accessory (assumed female dimorphic) spines. Sensory spots present in ventromedial positions, at margins of sternal extensions. The segment is devoid of cuticular hairs, but has a dense covering of minute cuticular hair-like structures on tergal and sternal extensions. Tergal extensions are triangular and sternal extensions rounded, with fringed margins (Figs 22A–B, 24M–O).</p><p>Distribution</p><p>Antarctic Peninsula: Open continental shelf off the Antarctic Peninsula, 596 m b.s.l. See Fig. 1 for geographic overview of stations and Table 1 for station and specimen information.</p><p>Diagnostic remarks</p><p>We would usually hesitate to describe a species based only on SEM specimens. First of all, the SEM specimens deteriorate much faster than specimens mounted for LM, which shortens the available time span for re-examining the type material. Second, certain internal or intracuticular structures, such as pachycycli are difficult to visualise with SEM. However, we still chose to describe E. crux sp. nov. because of its very distinct morphology and clear phylogenetic affinities within the genus.</p><p>The most distinct character trait in E. crux sp. nov. is the numerous series of minute glandular cell outlets type 2, which sums up to 35 pairs in total. Such a morphology is only shared with a single congener, E. aragorni . Males of E. aragorni also have exactly 35 pairs of glandular cell outlets type 2, whereas the females have 34 (Grzelak &amp; Sørensen 2022). Besides the type 2 outlets on segments 2 to 9, they also share the presence of openings near the anterior margin of segment 1. In E. aragorni these openings are elongate, which is why Grzelak &amp; Sørensen (2022) referred to them as ‘slit-like openings’. In E. crux the openings are perfectly round, but for the sake of terminological consistency, and in order to stress the homology between the structures in the two species, we also choose to refer to them as slit-like openings in E. crux . Grzelak &amp; Sørensen (2022) discussed whether the openings on segment 1 should also be seen as a variation of glandular cell outlets type 2. It would require a comparative study of histological sections to confirm or reject this suggestion, and suitable material for a study like this is currently not available. However, we find it quite likely that there is a homology between the openings on segment 1, and the type 2 outlets on the following segments.</p><p>Thus, based on the presence of these openings on segment 1 and the numerous type 2 outlets on the following eight segments, the close relationship between the two species is undisputable. They are, however, still easily distinguished from each other. The most distinct difference between the two species is the lack of lateroventral spines on segments 6 and 7 in E. aragorni . In addition, there are several differences in the distribution of slit-like openings and glandular cell outlets type 2. Besides minor (interpretive) differences in longitudinal positioning, E. crux sp. nov. differs from E. aragorni by having one additional pair of slit-like openings on segment 1, and by having seven pairs of type 2 outlets on segment 2, unlike the ‘only’ five pairs in E. aragorni . In contrast, E. aragorni has four pairs of type 2 outlets on segment 4, whereas E. crux only has three. The number and approximate position of type 2 outlets on the remaining segments is the same for the two species and seems to be conserved. Males of E. aragorni have an additional pair of type 2 outlets in laterodorsal positions of segment 10, but since no males are yet available for E. crux, it is not possible to confirm whether this species shows the same sexual dimorphism.</p><p>The mapping of glandular cell outlets type 1 in the dorsal series of E. crux sp. nov. is not complete, but besides the uncertain appearance of a middorsal type 1 outlets on segment 2, the observed pattern fits the very common MD Seg. 1–3, 5, 7, PD 4, 6, 8–9 pattern, which is also present in most other species of the present study. The mapping of dorsal type 1 outlets in E. aragorni is very incomplete, but it is noteworthy that both E. aragorni and E. crux have only a single middorsal type 1 outlet on segment 10, unlike the otherwise extremely common presence of two, longitudinally aligned middorsal outlets.</p></div>	https://treatment.plazi.org/id/03AE4066FFFCD407177DFED7FAE0FB95	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Sørensen, Martin V.;Macheriotou, Lara;Braeckman, Ulrike;Smith, Craig R.;Ingels, Jeroen	Sørensen, Martin V., Macheriotou, Lara, Braeckman, Ulrike, Smith, Craig R., Ingels, Jeroen (2025): Antarctic Kinorhyncha: Seven new species from the Antarctic Peninsula. European Journal of Taxonomy 1000 (1): 1-102, DOI: 10.5852/ejt.2025.1000.2947, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2947/13307
03AE4066FFF5D40014D6FB06FB3CFDCF.text	03AE4066FFF5D40014D6FB06FB3CFDCF.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Echinoderes angustus Higgins & Kristensen 1988	<div><p>Echinoderes aff. angustus Higgins &amp; Kristensen, 1988</p><p>Figs 25–26, Tables 19–20</p><p>Material examined</p><p>ANTARCTICA – Antarctic Peninsula • 1 ♂ (mounted for LM in Fluoromount G on HS slide); CRS 1698; 64°51.60′ S, 62°33.80′ W; 541 m b.s.l.; 28 Nov. 2015; FjordEco1; soft sediment; NHMD 1790691 • 1 ♀ (mounted for SEM); CRS 1702; 64°51.15′ S, 62°34.44′ W; 502 m b.s.l.; 30 Nov. 2015; FjordEco1; soft sediment; MVS • 1 ♂ (mounted for SEM); CRS 1773; 64°52.35′ S, 62°25.88′ W; 553 m b.s.l.; 6 Apr. 2016; FjordEco2; soft sediment; MVS • 1 ♂ (mounted for SEM); CRS 1776; 64°52.53′ S, 62°33.90′ W; 551 m b.s.l.; 7 Apr. 2016; FjordEco2; soft sediment; MVS • 1 ♀ (mounted for LM in <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-62.566833&amp;materialsCitation.latitude=-64.85667" title="Search Plazi for locations around (long -62.566833/lat -64.85667)">Fluoromount</a> G on HS slide); CRS 1792; 64°51.40′ S, 62°34.01′ W; 525 m b.s.l.; 11 Apr. 2016; FjordEco2; soft sediment; NHMD 1790692 • 1 ♂, 1 ♀ (mounted for SEM); CRS 1793; 64°39.53′ S, 62°55.03′ W; 701 m b.s.l.; 11 Apr. 2016; FjordEco2; soft sediment; MVS • 1 ♂ (mounted for LM in Fluoromount G on HS slide); CRS 1809; 64°39.59′ S, 62°55.09′ W; 694 m b.s.l.; 15 Apr. 2016; FjordEco2; soft sediment; NHMD 1790693 • 2 ♂♂ (mounted for SEM); CRS 1809; 64°39.59′ S, 62°55.09′ W; 694 m b.s.l.; 15 Apr. 2016; FjordEco2; soft sediment; MVS .</p><p>Concise description</p><p>Except when clearly specified, the following concise description applies to both the Antarctic population of Echinoderes aff. angustus and to the Arctic type material, as well as supplementary specimens of E. angustus mounted for SEM.</p><p>GENERAL. An overview of measurements and dimensions is given in Table 19. Distributions of cuticular structures, i.e., sensory spots, glandular cell outlets, spines and tubes, are summarized in Table 20.</p><p>SEGMENT 1. Consists of a complete cuticular ring. Sensory spots are present in subdorsal, laterodorsal, and ventromedial positions; sensory spots are minute, and consist of relatively few, very short micropapillae arranged around two pores. Glandular cell outlets type 1 are present in middorsal and lateroventral positions. Cuticular hairs are arranged in three to four rows: anterior two to three rows are present only on the dorsal side, between midlateral positions, whereas the posteriormost row extends around the entire segment. The posterior segment margin is straight and terminates in a pectinate fringe with broad and well-developed slender fringe tips; fringe tips on ventral side are slightly longer than those on the lateral and dorsal sides (Figs 25A–D, 26A–C).</p><p>SEGMENT 2. Consists of a complete cuticular ring. However, a partially developed, midventral fissure is visible in the Arctic type specimens of E. angustus (Fig. 25F). Indications of such a fissure were never observed in any of the Antarctic specimens (Fig. 25E). Glandular cell outlets type 2 are present in subdorsal, laterodorsal, sublateral, and ventrolateral positions. Sensory spots are present in middorsal, laterodorsal, midlateral, and ventromedial positions; the micropapillary areas around the sensory spots on this, and all following segments, are even smaller than those on segment 1 and form a slightly oval ring around a single pore; one or two long and rigid hairs (extremely extended micropapillae?) stick out from the micropapillary area. Glandular cell outlets type 1 are present in middorsal and ventromedial positions. Fairly long bracteate cuticular hairs are arranged in three to four transverse rows on the dorsal and lateral sides; ventromedial and paraventral areas without hairs. The posterior segment margin is straight, terminating in uniform, well-developed fringe tips (Figs 25A–F, 26A–C).</p><p>SEGMENT 3. As following seven segments, consisting of one tergal and two sternal plates. Sensory spots are present in subdorsal and sublateral positions, and glandular cell outlets type 1 in middorsal and ventromedial positions. Cuticular hairs present in four rows on the tergal and lateral halves of the sternal plates, except in hair-less midlateral areas; paraventral areas and most ventral parts of ventromedial areas completely free of hairs and hair-like structures. Posterior segment margin straight and pectinate fringe as on preceding segment (Figs 25A–B, 26A–B, D).</p><p>SEGMENT 4. With spine in middorsal position. Glandular cell outlets type 2 are present in subdorsal positions. Sensory spots are not present. Glandular cell outlets type 1 are present in paradorsal and ventromedial positions. Cuticular hairs as on preceding segment, but now arranged in five rows. Posterior segment margin and pectinate fringe as on preceding segment (Figs 25A–B, 26A–B, D).</p><p>SEGMENT 5. With spine in middorsal position and tubes in lateroventral positions. Glandular cell outlets type 2 are present in midlateral positions. Sensory spots present in subdorsal and ventromedial positions, and glandular cell outlets type 1 in paradorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 25G–L, 26E–G).</p><p>SEGMENT 6. With spines in middorsal and lateroventral positions. Sensory spots present in paradorsal, subdorsal, midlateral, and ventromedial positions; ventromedial sensory spots situated closer to midventral articulation than those on preceding segment. Glandular cell outlets type 1 present in paradorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 25G–J, 26E–G).</p><p>SEGMENT 7. With spines in middorsal and lateroventral positions. Sensory spots present in paradorsal, midlateral, and ventromedial positions; ventromedial sensory spots situated more lateral than those on preceding segment and aligned with those on segment 5. Glandular cell outlets type 1 present in paradorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 25G–J, 26E–I).</p><p>SEGMENT 8. With spines in middorsal and lateroventral positions. Glandular cell outlets type 2 are present in sublateral positions. Sensory spots present in paradorsal positions only, and glandular cell outlets type 1 in paradorsal and ventromedial positions. Cuticular hairs as on preceding segment, but the midlateral hairless areas have moved to more laterodorsal positions, and middorsal to paradorsal positions are also devoid of hairs. Posterior segment margin and pectinate fringe as on preceding segment (Figs 25G–J, M–N, 26G–I).</p><p>SEGMENT 9. With spines in lateroventral positions. Sensory spots present in paradorsal, subdorsal, midlateral, and ventrolateral positions.Glandular cell outlets type 1present in paradorsal and ventromedial positions. Small rounded sieve plates located in sublateral positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 25O–P, R–S, 26H–J).</p><p>SEGMENT 10. With glandular cell outlets type 2 in laterodorsal positions near posterior segment margin. Sensory spots present in subdorsal and ventrolateral positions. Glandular cell outlets type 1 present as two longitudinally arranged outlets in middorsal position and in ventromedial positions. Cuticular hair covering reduced to a few (4 to 6) hairs in subdorsal positions and otherwise only hairs in laterodorsal to ventromedial areas. The posterior segment margin of the tergal plate is straight, with minute fringe tips. Sternal plate margins oblique, with longer fringe tips in ventromedial and paraventral areas (Figs 25O, Q, R–S, U, 26J–M).</p><p>SEGMENT 11. With lateral terminal spines and a middorsal protuberance emerging from the intersegmental zone between segments 10 and 11. The segment appears to consist of two tergal and two sternal plates. The visualisation of the middorsal fissure between the tergal plates easily gets obscured by the overlaying protuberance, but the presence of the fissure was nevertheless confirmed in both Antarctic (Fig. 25T) and Arctic (Fig. 25U) specimens. Females with lateral terminal accessory spines; males with thin, tubular dorsal and ventral penile spines; medial pair of penile spines cone-shaped and well-developed. Males in addition with short tubes inserted near bases of dorsal and medial penile spines; the tubes resemble an extra set of penile spines, but are much shorter, roughly 5 µm estimated from SEM; due to their minute size and the numerous other structures in this area, the tubes are difficult to visualise with LM. The presence of these tubes is only confirmed for the Antarctic specimens. Sensory spots present in paradorsal positions only. The segment is devoid of cuticular hairs, but has scattered hair-like extensions over the tergal extensions. Tergal extensions are elongate triangular, with pointed tips. Sternal extensions short, broadly triangular, and not extending beyond tergal extensions (Figs 25R–U, 26K–M).</p><p>Distribution</p><p>Antarctic Peninsula: Gerlache Strait and Andvord Bay MBA and IBB, 502 to 701 m b.s.l. See Fig. 1 for geographic overview of stations and Table 1 for station and specimen information. Possibly also South Orkney Trench, 5 251 m b.s.l. (see Sánchez et al. 2024).</p><p>Diagnostic remarks</p><p>Echinoderes angustus was described from Disko Island in West Greenland (Higgins &amp; Kristensen 1988). It has subsequently been the subject of redescriptions and additional important notes have been added to the diagnosis of the species. Grzelak &amp; Sørensen (2018) documented the presence of glandular cell outlets type 2 in subdorsal, laterodorsal, sublateral, and ventrolateral positions on segment 2, in subdorsal positions on segment 4, in midlateral positions on segment 5, and (very likely) in laterodorsal positions on segment 10. Shortly after, Herranz et al. (2018) reported the presence of a partial midventral fissure in segment 2 and noted that E. angustus is most easily distinguished from the highly similar species E. pennaki by its longer (about 20%) middorsal and laterodorsal spines. Re-examinations of type material and fresh material collected close to the type locality was carried out during the present study. They confirm these observations, add a complete mapping of sensory spots (Table 20) in E. angustus, and confirm the presence of laterodorsal type 2 outlets on segment 10. In addition, the examinations revealed that the species has a middorsal protuberance projecting from the intersegmental zone between segments 10 and 11, and that the tergal plate of the terminal segment is split into two halves by a middorsal fissure. Visualisation of this middorsal fissure is often obscured by the overlaying protuberance.</p><p>Since its discovery, E. angustus has also been recorded from the Barents Sea and the fjords of Svalbard, where it is one of the most frequently observed species (Grzelak &amp; Sørensen 2019a, 2019b).This suggests that the species’ distributional range at least covers the Arctic extension of the Atlantic Ocean. In a recent study of kinorhynchs in the Subantarctic South Orkney Trench, not too distant from the Antarctic Peninsula, Sánchez et al. (2024) surprisingly found a specimen that almost matched the morphology of E. angustus . Its distribution of spines and glandular cell outlets type 2 matched the emended diagnoses provided by Grzelak &amp; Sørensen (2018) and Herranz et al. (2018), and the sensory spot distribution largely followed the pattern reported in the present study. The only two notable differences regarded its longer lateral terminal spines and the absence of a partial midventral fissure on segment 2. Based on the great level of similarity, but also taking the minor differences and the considerable geographic distance into account, Sánchez et al. (2024) reluctantly reported the species as Echinoderes cf. angustus .</p><p>Echinoderes aff. angustus, recorded in the present study, fits the Subantarctic specimen reported by Sánchez et al. (2024): its morphology is highly similar to that of E. angustus, but its lateral terminal spines are slightly longer, and there is no indication of a midventral fissure on segment 2. The difference in spine lengths is less pronounced though. Whereas the lateral terminal spines of the Subantarctic female specimen of Sánchez et al. (2024) measured 223 µm, unlike the only 140–180 µm in the female E. angustus types (Higgins &amp; Kristensen 1988), the lengths of these spines in the Antarctic specimen are only an extension of the size range in the male types (140–198 µm in male types vs 197–214 µm in male Antarctic specimens). The Antarctic specimens are certainly conspecific with the South Orkney Trench specimen reported by Sánchez et al. (2024); this is supported by morphology, morphometrics and geography. The open question is obviously whether these specimens can be considered as conspecific with E. angustus . The lateral terminal spine lengths can hardly be used as an argument to separate the Antarctic specimens from E. angustus, and even though the missing midventral fissure on segment 2 could indicate that they represent a distinct species, it is hard to accept this difference as the sole diagnostic character. The only other potential differential character is the short set of midlateral tubes found in male specimens on their terminal segment. Since these tubes are only visible with SEM, the type material of E. angustus is not useful to confirm or reject the presence of such tubes in E. angustus . However, a single male E. angustus specimen from Svalbard did not seem to have such tubes; thus, their presence in the Antarctic specimens could support that this is a different species.</p><p>The geographic distance between the Arctic and (Sub-)Antarctic populations obviously also speaks in favour of considering them as two different species, but we have recently seen indications of other species with a potential bipolar distribution. For instance, the high Arctic, north Atlantic, and Mediterranean species Echinoderes pterus has also been reported from the Atacama Trench, off Chile (Yamasaki et al. 2018a; Grzelak et al. 2021), and Grzelak &amp; Sørensen (2022) reported specimens from New Zealand showing a close resemblance to Echinoderes beringiensis, which, as the name indicates, was described from the Bering Strait (Adrianov &amp; Maiorova, 2022) (see also the following section for an additional discussion of this species). With these indications of potential bipolar kinorhynch distributions taken into account, we cannot rule out that E. angustus could also be present in both the Arctic and Antarctic. Thus, the only fair conclusion at this stage seems to be that it would require comparison of molecular barcodes to solve the question. It is intriguing, though, to experience how we keep observing extremely wide distributions of conspecific populations, or at least very closely related species.</p></div>	https://treatment.plazi.org/id/03AE4066FFF5D40014D6FB06FB3CFDCF	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Sørensen, Martin V.;Macheriotou, Lara;Braeckman, Ulrike;Smith, Craig R.;Ingels, Jeroen	Sørensen, Martin V., Macheriotou, Lara, Braeckman, Ulrike, Smith, Craig R., Ingels, Jeroen (2025): Antarctic Kinorhyncha: Seven new species from the Antarctic Peninsula. European Journal of Taxonomy 1000 (1): 1-102, DOI: 10.5852/ejt.2025.1000.2947, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2947/13307
03AE4066FFF2D41614F5FDA5FE6FFCC0.text	03AE4066FFF2D41614F5FDA5FE6FFCC0.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Echinoderes beringiensis Adrianov & Maiorova 2022	<div><p>Echinoderes aff. beringiensis /romanoi/xalkutaat</p><p>Figs 27–28, Tables 21–22</p><p>Material examined</p><p>ANTARCTICA – Antarctic Peninsula • 1 ♀ (mounted for LM in Fluoromount G on HS slide); CRS 1793; 64°39.53′ S, 62°55.03′ W; 701 m b.s.l.; 11 Apr. 2016; FjordEco2; soft sediment; NHMD 1790694 • 1 ♂ (mounted for SEM); CRS 1793; 64°39.53′ S, 62°55.03′ W; 701 m b.s.l.; 11 Apr. 2016; FjordEco2; soft sediment; MVS • 1 ♂, 3 ♀♀ (mounted for LM in Fluoromount G on HS slide.); CRS 1809; 64°39.59′ S, 62°55.09′ W; 694 m b.s.l.; 15 Apr. 2016; FjordEco2; soft sediment; NHMD 1790695 to 1790698 • 2 ♂♂, 3 ♀♀ (mounted for SEM); CRS 1809; 64°39.59′ S, 62°55.09′ W; 694 m b.s.l.; 15 Apr. 2016; FjordEco2; soft sediment; MVS • 2 ♀♀ (mounted for SEM); CRS 1832; 64°39.30′ S, 62°55.98′ W; 631 m b.s.l.; 21 Apr. 2016; FjordEco2; soft sediment; MVS .</p><p>Concise description</p><p>GENERAL. An overview (Fig. 27A) of measurements and dimensions is given in Table 21. Distributions of cuticular structures, i.e., sensory spots, glandular cell outlets, spines and tubes, are summarized in Table 22.</p><p>SEGMENT 1. Consists of a complete cuticular ring. Sensory spots are present in subdorsal, laterodorsal, and ventromedial positions; sensory spots are minute, and consist of relatively few, very short micropapillae arranged around two pores. Glandular cell outlets type 1 are present in middorsal and lateroventral positions. Cuticular hairs are arranged in four to five rows: anterior rows are present only on dorsal side, between midlateral positions, whereas the posteriormost row extends around the entire segment; an additional short row is present between the ventromedial sensory spots. The posterior segment margin is straight and terminates in a pectinate fringe with broad and well-developed fringe tips; fringe tips on ventral side are slightly longer than those on the lateral and dorsal sides (Figs 27B–C, 28A–C).</p><p>SEGMENT 2. Consists of a complete cuticular ring, without any indication of a midventral fissure.Glandular cell outlets type 2 are present in subdorsal, laterodorsal, sublateral, and ventrolateral positions. Sensory spots are present in middorsal, laterodorsal, midlateral, and ventromedial positions; the micropapillary areas around the sensory spots on this, and all following segments, are small and rounded, and point in a posterior direction; one or two long and rigid hairs (extremely extended micropapillae?) project from the micropapillary area. Glandular cell outlets type 1 are present in middorsal and ventromedial positions. Fairly long bracteate cuticular hairs are arranged in four to five transverse rows around the segment. The posterior segment margin is straight, terminating in uniform, well-developed fringe tips (Figs 27B–C, 28A–C).</p><p>SEGMENT 3. As following seven segments, consisting of one tergal and two sternal plates. Sensory spots are present in subdorsal (not present in all specimens) and sublateral positions, and glandular cell outlets type 1 in middorsal and ventromedial positions. Cuticular hairs present in four to five rows on the tergal and lateral halves of the sternal plates, except in hair-less midlateral areas; paraventral areas completely devoid of hairs or hair-like extensions. Posterior segment margin straight and pectinate fringe as on preceding segment (Figs 27B–C, 28D–F).</p><p>SEGMENT 4. With spine in middorsal position. Sensory spots are not present. Glandular cell outlets type 1 are present in paradorsal and ventromedial positions. Cuticular hairs as on preceding segment, but now arranged in five to six rows. Posterior segment margin and pectinate fringe as on preceding segment (Figs 27B–C, 28D–F).</p><p>SEGMENT 5. With spine in middorsal position and tubes in lateroventral positions. Glandular cell outlets type 2 are present in midlateral positions. Sensory spots present in subdorsal and ventromedial positions, and glandular cell outlets type 1 in paradorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 27B–D, 28F–I).</p><p>SEGMENT 6. With spines in middorsal and lateroventral positions. Sensory spots present in paradorsal, subdorsal, midlateral, and ventromedial positions; ventromedial sensory spots situated closer to midventral articulation than those on preceding segment. Glandular cell outlets type 1 present in paradorsal and ventromedial positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 27B–F, 28G–I).</p><p>SEGMENT 7. With spines in middorsal and lateroventral positions. Sensory spots present in paradorsal, midlateral, and ventromedial positions; ventromedial sensory spots situated more laterally than those on preceding segment and aligned with those on segment 5. Glandular cell outlets type 1 present in paradorsal and ventromedial positions. Cuticular hairs as on preceding segment, except for middorsal to paradorsal positions which are also devoid of hairs. Posterior segment margin and pectinate fringe as on preceding segment (Figs 27D–F, 28I–L).</p><p>SEGMENT 8. With spines in middorsal and lateroventral positions. Glandular cell outlets type 2 are present in sublateral positions. Sensory spots present in paradorsal positions only, and glandular cell outlets type 1 in paradorsal and ventromedial positions. Cuticular hairs as on preceding segment, but the midlateral hairless areas have moved to more laterodorsal positions. Posterior segment margin and pectinate fringe as on preceding segment (Figs 27D–F, 28L–N).</p><p>SEGMENT 9. With spines in lateroventral positions. Sensory spots present in paradorsal, subdorsal, midlateral, and ventrolateral positions.Glandular cell outlets type 1present in paradorsal and ventromedial positions. Small rounded sieve plates located in sublateral positions. Cuticular hairs, posterior segment margin, and pectinate fringe as on preceding segment (Figs 27E–F, H, 28O–Q).</p><p>SEGMENT 10. With glandular cell outlets type 2 in laterodorsal positions near posterior segment margin. Sensory spots present in subdorsal and ventrolateral positions. Glandular cell outlets type 1 present as two longitudinally arranged outlets in middorsal position, and in ventromedial positions. Cuticular hair covering reduced to a small patch between subdorsal sensory spots, and otherwise only hairs in laterodorsal to ventromedial areas. The posterior segment margin of the tergal plate is straight, with minute fringe tips. Sternal plate margins oblique, with longer fringe tips in ventromedial and paraventral areas (Figs 27G–J, 28R–U).</p><p>SEGMENT 11. With lateral terminal spines and a middorsal protuberance emerging from the intersegmental zone between segments 10 and 11. The segment consists of two tergal and two sternal plates, but visualisation of the middorsal fissure between the tergal plates is obscured by the overlaying protuberance. Females with lateral terminal accessory spines; males with thin, tubular dorsal and ventral penile spines; medial pair of penile spines cone-shaped and well-developed. Males in addition with thin tube, attaching between dorsal and medial penile spines; the tube diameter is&gt; 50% of the dorsal penile spine diameter and&gt;20% of the penile spine length. Sensory spots present in paradorsal positions only. The segment is devoid of cuticular hairs, but has scattered hair-like extensions along the inferior margins of the tergal plates. Tergal extensions are triangular, with pointed tips. Sternal extensions short, broadly triangular, and not extending beyond tergal extensions (Figs 27G–J, 28R–U).</p><p>Distribution</p><p>Antarctic Peninsula: Gerlache Strait, 631 to 701 m b.s.l. See Fig. 1 for geographic overview of stations and Table 1 for station and specimen information.</p><p>Diagnostic remarks</p><p>Identification of these specimens turned out to be difficult, since they show a very close resemblance with no less than three congeners, i.e., E. beringiensis, E. romanoi, and E. xalkutaat . This high level of similarity not only hampers identification of the Antarctic specimens, but also indicates that the three species in question potentially could be synonymous. In the following, comparison of the Antarctic specimens with each of the three species will be carried out in separate sections. In addition, a comparison with E. angustus, E. aff. angustus (addressed above) and E. aff. beringiensis / galadrielae sensu Grzelak &amp; Sørensen (2022) will be included, since these species also share so many similarities that it could indicate the existence of a new species group. Observed differences between the species are summarised in Table 23.</p><p>Comparison with E. beringiensis</p><p>The distribution of spines and sensory spots on segments 1 to 9 is nearly identical in E. beringiensis and the Antarctic Echinoderes aff. beringiensis / romanoi / xalkutaat (Adrianov &amp; Maiorova 2022; Table 22 in present contribution). The only detectable difference regards the tubes on segment 5, which are displaced to a lateral accessory position in E. beringiensis (see Adrianov &amp; Maiorova 2022: figs 5a, 6a). The two species also share the same segment compositions, including the midtergal division of segment 11. Morphometric ranges for trunk and spine lengths are also overlapping in nearly all cases, except regarding the lateral terminal spines, which are longer in the Antarctic species, 177–205 µm vs 123–168 µm (Table 21). The potential main differences between the two species might be found in their distribution of glandular cell outlets type 2. They have outlets in identical positions on segments 2 and 8. However, adult female specimens of E. beringiensis appear to have two pairs of outlets on segment 8, in midlateral and sublateral positions, as opposed to only a single pair in sublateral positions in the Antarctic specimens. Having a double set of large glandular cell outlets 2 type on segment 8 is truly a unique trait among species of Echinoderes, but the diagnostic value of the character gets challenged by the fact that it has only been observed in five (?) adult females (and documented in one), whereas males and younger females only have the much more common sublateral pair (Adrianov &amp; Maiorova 2022). It would be desirable to obtain a better understanding of this trait and, eventually through observation of a larger sample size, decide whether this is truly a consistent character or if the double outlet pairs are abnormalities.</p><p>Another potential difference might be found in the laterodorsal positions of the posterior segment margin of segment 10, where E. beringiensis is reported to have sensory spots (Adrianov &amp; Maiorova 2022), unlike the Antarctic specimens which have glandular cell outlets type 2 in these positions. However, these structures are quite well documented in the description of E. beringiensis, and fig. 8e in Adrianov &amp; Maiorova (2022) clearly shows that the structures are glandular cell outlets type 2 rather than sensory spots.</p><p>Otherwise, there are no conspicuous differences between E. beringiensis and the Antarctic Echinoderes aff. beringiensis / romanoi / xalkutaat, and potential differences narrow down to the lengths of their lateral terminal spines, and the somehow questionable double pair of glandular cell outlets type 2 on segment 8.</p><p>Comparison with Echinoderes aff. beringiensis / galadrielae sensu Grzelak &amp; Sørensen (2022)</p><p>Following their description of E. galadrielae from New Zealand, Grzelak &amp; Sørensen (2022) reported the co-occurring species Echinoderes aff. beringiensis / galadrielae, which appeared to “represent an intermediate between E. galadrielae sp. nov. and E. beringiensis ” (Grzelak &amp; Sørensen 2022: 82) . The distribution of cuticular structures generally followed the pattern of E. galadrielae, whereas the tergal extensions were similar with those in E. beringiensis and thus differing considerably from the long and slender extensions in E. galadrielae .</p><p>Comparison with Echinoderes aff. beringiensis / romanoi / xalkutaat reveals that the Antarctic specimens are nearly identical with Echinoderes aff. beringiensis / galadrielae . The spine/tube pattern of the two species differs only in the position of tubes on segment 5 (lateral accessory vs lateroventral), and even the spine length ranges overlap. The only conspicuous morphometric difference between the two species regards the considerable difference in trunk length, i.e., 271–313 µm in the Antarctic species vs 210–235 µm in the New Zealand species. There are, however, more considerable differences in the sensory spot distribution, as the New Zealand species apparently lacks ventromedial sensory spots on segments 1, 5, and 7, and subdorsal sensory spots on segment 6, which are all present in the Antarctic species. The absence of subdorsal structures on segment 6 could potentially be due to intraspecific variation, and the missing ones on segments 5 and 7 might have been hidden under dirt, but the absence of ventromedial sensory spots on segment 1 is a distinct difference that could speak against conspecificity.</p><p>Echinoderes aff. beringiensis / galadrielae is reported to have males with short laterodorsal tubes on segment 10, whereas the females have ‘similar slit-like, fringed openings’ (Grzelak &amp; Sørensen 2022). However, a re-examination of the specimens clearly shows that these structures are glandular cell outlets type 2, which corresponds to the morphology in the Antarctic specimens.</p><p>Segment 11 is similar in composition, i.e., consisting of two tergal and two sternal plates, but it differs by the lack of a middorsal protuberance in the New Zealand species. An additional apparent difference between the two species regards the cuticular hair covering, which generally is much denser on the Antarctic specimens.</p><p>Comparison with E. romanoi</p><p>The comparison of the Antarctic species with E. romanoi from the Gulf of Mexico prompted some re-examinations of E. romanoi type specimens as well as non-types mounted for SEM. Unfortunately, the latter were in a rather sad condition, but new and significant information was nevertheless obtained. Most importantly, it could be documented that E. romanoi has laterodorsal glandular cell outlets on segment 10, and that the tergal plate of segment 11 has a middorsal fissure (Fig. 29B, D). Furthermore, some minor details in the original description could be corrected, i.e., 1) that the reported sublateral glandular cell outlets type 1 on segment 1 are muscular attachment sites, 2) that a middorsal sensory spot and glandular cell outlet type 1 are present on segment 2, 3) that segment 3 has a single middorsal glandular cell outlet type 1, rather than a pair of paradorsal outlets, and 4) that laterodorsal sensory spots on segment 10 are missing, whereas ventrolateral ones are present. Likewise, type specimens were remeasured (Table 21), and a couple of potential pre-adults that were part of the original morphometric data provided by Landers &amp; Sørensen (2016) were excluded.</p><p>With this new information established, the spine, sensory spot, and glandular cell outlet patterns for the Antarctic species and E. romanoi are the same, and differences come down to morphometrics and the absence of a middorsal protuberance on segment 11 in E. romanoi . Morphometrically, E. romanoi differ from the Antarctic species by being smaller. The trunk is shorter, 196–247 µm vs 271–313 µm, and all middorsal and laterodorsal spines are generally about 20% shorter in E. romanoi (see Table 21). Only the length ranges of the lateral terminal spines are overlapping in the two species.</p><p>Comparison with E. xalkutaat</p><p>Echinoderes xalkutaat is known from the Gulf of California, and the description was based on three specimens mounted for LM (Cepeda et al. 2019b). The condition of the type material could have been better, and with the lack of information from SEM, some characters in E. xalkutaat remain to be confirmed. However, it is clear that the distribution patterns of spines, tubes, and glandular cell outlets types 1 and 2 are identical with the patterns in the Antarctic species. Morphometrically, ranges of trunk and spine lengths are also overlapping for the two species (Table 21).</p><p>Potential differences might be found in the sensory spot distribution and characters related to the terminal segment. As for the latter, E. xalkutaat is described as having a terminal segment with a complete tergal plate and no middorsal protuberance. However, due to the condition of the type specimens, this information needs to be validated. It is correct that there is no evidence for the presence of a protuberance, but the dorsal view of segment 11 shown in fig. 16i by Cepeda et al. (2019a) actually has indications of a middorsal fissure on the segment, suggesting that the tergal plate could be split into two. Regarding sensory spots, the main difference appears to be expressed in the dorsal series, which are more laterodorsal in E. xalkutaat, as opposed to subdorsal in the Antarctic specimens, but again, confirmation from SEM would be desirable.</p><p>Comparison with Arctic E. angustus and Antarctic E. angustus and E. aff. angustus</p><p>The Arctic species E. angustus and the Antarctic E. angustus and E. aff. angustus clearly differ from Echinoderes aff. beringiensis / romanoi / xalkutaat and the other species discussed above by having subdorsal glandular cell outlets on segment 4. They have, however, been included in the comparison because of the striking similarities regarding all other cuticular structures. Morphometrically, E. angustus and the Antarctic, potentially conspecific population are in the upper range or larger than Echinoderes aff. beringiensis / romanoi / xalkutaat, both regarding trunk and lateral terminal spine lengths, but the ranges of other spines are overlapping. When it comes to cuticular hairs, spines, tubes, and glandular cell outlets (except type 2 outlets on segment 4), the species are basically identical, which stresses the close phylogenetic relationship between the species.</p><p>In conclusion, E. angustus and the Antarctic E. angustus and E. aff. angustus are easily distinguished from the other species in question based on their presence of subdorsal glandular cell outlets type 2 on segment 4. When it comes to the remaining species, the differential characters are much more subtle, and clear species barriers are questionable. Echinoderes beringiensis might be distinguished by its double set of glandular cell outlets type 2 on segment 8 in females, but since this character does not appear consistently – not even amongst females – its taxonomic significance needs to be validated. Echinoderes aff. beringiensis / galadrielae from New Zealand is perhaps the potential species that stands out the most, by its consistent lack of ventromedial sensory spots on segment 1. At the same time, it is also smaller than the other species, and the range of its trunk length only overlaps with that of E. romanoi . The latter species does not really stand out in any conspicuous way. One potential differential character could be the absence of a middorsal protuberance on segment 11, but since we have very limited understanding of the variability and taxonomic significance of this character, we would be hesitant about basing the species diagnosis exclusively on this trait. Echinoderes xalkutaat might be recognised by its slightly different sensory spot pattern, but since the species description is based on LM observations of very few specimens in relatively poor condition, the general morphology of this species needs to be validated. Thus, to sum up, it is not possible to assign the Antarctic Echinoderes aff. beringiensis / romanoi / xalkutaat to any known species. Instead, the three candidate species could potentially be synonymous, and morphological re-examinations, or ideally molecular barcoding, are required to solve the taxonomic nature of these species.</p></div>	https://treatment.plazi.org/id/03AE4066FFF2D41614F5FDA5FE6FFCC0	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Sørensen, Martin V.;Macheriotou, Lara;Braeckman, Ulrike;Smith, Craig R.;Ingels, Jeroen	Sørensen, Martin V., Macheriotou, Lara, Braeckman, Ulrike, Smith, Craig R., Ingels, Jeroen (2025): Antarctic Kinorhyncha: Seven new species from the Antarctic Peninsula. European Journal of Taxonomy 1000 (1): 1-102, DOI: 10.5852/ejt.2025.1000.2947, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2947/13307
