Sphaerephesia philippi (Fauvel, 1911) Fauvel, 1911

Capa, Maria, Nygren, Arne, Parapar, Julio, Bakken, Torkild, Meissner, Karin & Moreira, Juan, 2019, Systematic re-structure and new species of Sphaerodoridae (Annelida) after morphological revision and molecular phylogenetic analyses of the North East Atlantic fauna, ZooKeys 845, pp. 1-97 : 51-54

Sphaerephesia philippi (Fauvel, 1911) comb. n. Figs 5O, 8D, 15K, L, 20

Sphaerodorum philippi Fauvel, 1911: 19-21, fig. 16-20 (not S. philippi Hartmann-Schröder, 1971).

Type locality.

Kara Sea, Russia, 71°32'N, 57°10'E, 220-0 m.

Material examined.

(ca 1480 specs) Greenland Sea: ZMBN 127275 (~25 spec.), 68°53.5'N, 14°14.3'W, 1588 m, 15 Mar 1984; ZMBN 127287 (15 spec.), Jan Mayen, 70°48.6'N, 09°43.7'W, 886 m, 27 Jul 1986; ZMBN 127295 (4 spec.), 69°57.3'N, 18°08.9'W, 1618 m, 12 Jun 1987; NTNU-VM 32347 (2 spec.), Jan Mayen, 70°36.19'N, 9°20.72'W, 31 m, 17 Sep 1999; NTNU-VM 32348 (15 spec.), Jan Mayen, 71°06.41'N, 9°35.26'W, 514 m, 15 Sep 1999; NTNU-VM 32349 (35 spec.), Jan Mayen, 70°45.07'N, 7°57.74'W, 771 m, 16 Sep 1999; NTNU-VM 32350 (496 spec., 1 on SEM), Jan Mayen, 70°38.87'N, 9°22.33'W, 599 m, 17 Sep 1999; SMF 24843 (1 spec. for DNA sequencing, SPH052), East Greenland, Denmark Strait, 67°12.81'N, 026°14.50'W, 696.9 m, 14 Sep 2011; SMF 25287 (7 specs), East Greenland, Denmark strait, 67°50.79'N, 023°41.76'W, 1248 m, 15 Sep 2011; SMF 25288DZMB-HH 30452 (3 specs), East Greenland, Denmark Strait, 67°50.79'N, 023°41.76'W, 1248 m, 15 Sep 2011; SMF 25289 (4 specs), East Greenland, Denmark Strait, 67°50.790'N, 23°41.760'W, 1248 m, 15 Sep 2011; SMF 25290 (1 spec.), East Greenland, Denmark Strait 67°38.77'N, 026°44.78'W, 320 m, 14 Sep 2011; Iceland: SMF 25291 (6 specs), East Iceland, Norwegian Sea, 66°18.06'N, 012°22.38'W, 730,8m¸ 22 Sep 2011; SMF 25292 (1 specs), East Iceland, 66°18.06'N, 012°22.38'W, 730,8m¸ 22 Sep 2011; SMF 23903 (1 for DNA sequencing), North East Iceland, 69°6.66'N, 9°55.02'W, 2202 m, 17 Sep 2011; SMF 25293 (3 specs), North East Iceland, 69°6.66'N, 9°55.02'W, 2202 m, 17 Sep 2011; SMF 23903 (1 spec. For DNA sequencing, SPH061), North East Iceland, 69°6.66'N, 9°55.02'W, 2202 m, 17 Sep 2011; SMF 25294; (2 specs), South Iceland, Iceland Basin, 62°33.50'N, 020°21.18'W, 1392m, 2 Sep 2011; Barents Sea: ZMBN 127298 (5 spec.), Finnmark, 71°16.53'N, 27°0.94'E, 276 m, 16 Apr 2011; ZMBN 127305 (6 spec.), Finnmark, 71°11.415'N, 32°14.991'E, 226 m, 10 Aug 2013; ZMBN 127323 (10 spec.), Finnmark, 70°17.79'N, 31°18.83'E, 217 m, 18 Aug 2013; Norwegian Sea: ZMBN 127299 (10 spec.), Nordland, 67°48.276'N, 9°41.126'E, 823 m, 22 Sep 2011; ZMBN 127302 (18 spec.), Nordland, 67°57.337'N, 9°35.556'E, 1315 m, 6 May 2012; ZMBN 127301 (18 spec.), Nordland, 68°3.937'N, 9°28.129'E, 1712 m, 6 May 2012; ZMBN 127304 (24 spec.), Nordland, 67°17.06'N, 8°7.982'E, 1117 m, 8 May 2012; ZMBN 129496 (1 spec. on SEM stub), 67°17.0604'N, 8°7.9824'E, 1117 m, 8 May 2012; ZMBN 127264 (~30 spec.) 67°47.0'N, 07°43.9'E, 2025 m, 03 Jun 1981; ZMBN 127265 (~40 spec.), 65°39.5'N, 02°38.0'E, 2019 m, 07Jun 1981; ZMBN 127267 (~50 spec.), 63°35.6'N, 00°23.0'E, 2090 m, 15 Aug 1981; ZMBN 127266 (2 spec.), 64°16.9'N, 00°11.7'W, 2630 m, 14 Aug 1981; ZMBN 127268 (3 spec.), 62°29.5'N, 01°43.3'E, 604 m, 21 Jan 1982; ZMBN 127269 (10 spec.), 63°12.8'N, 03°07.3'E, 1003 m, 23 Aug 1982; ZMBN 127270 (6 spec.) 62°59.1'N, 03°13.1'E, 804 m, 27 Nov 1982; ZMBN 127272 (1 spec.), 64°26.1'N, 11°10.2'W, 400 m, 07 Jun 1983; ZMBN 127274 (2 spec.), 68°42.4'N, 10°29.5'W 2168 m, 13 Mar 1984; ZMBN 127276 (~100 spec.), 67°39.5'N, 11°36.7'W, 1811 m, 16 Mar 1984; ZMBN 127277 (~50 spec.), 62°35.1'N, 1°47.6'E, 656 m, 23 May 1984; ZMBN 127278 (1 spec.), 62°35.4'N, 01°47.7'E, 650 m, 23 May 1984; ZMBN 127279 (~ 25 spec.), 62°33.2'N, 01°49.2'E, 625 m, 21 Nov 1984; ZMBN 127280 (~50 spec.), 62°31.5'N, 01°26.6'E, 701 m, 08 Jan 1985; ZMBN 127281 (2 spec.), 63°45.2'N, 00°08.0'W, 2304 m, 11 Jan 1985; ZMBN 127282 (~20 spec.), 63°24.4'N, 00°20.3'E, 1880 m, 12 Jan 1985; ZMBN 127283 (~50 spec.), 63°02.9'N, 00°47.8'E, 1293 m, 12 Jan 1985; ZMBN 127284 (1 spec.), Faroes, 62°44.7'N, 06°46.9'W, 2538 m, 24 Jul 1986; ZMBN 127285 (~100 spec.), 69°01.4'N, 08°24.6'W, 879 m, 25 Jul 1986; ZMBN 129497 (1 spec. on SEM stub), 1243m, 70°40.68'N, 7°37.86'W, 27. Jul 1986, ZMBN 127286 (1 spec.), 69°36.4'N, 09°54.6'W, 2212 m, 26 Jul 1986; ZMBN 127289 (2 spec.), 70°26.2'N, 06°31.8'W, 2525 m, 28 Jul 1986; ZMBN 127290 (~20 spec.), 62°36.6'N, 01°34.4'E, 654 m, 15 Aug 1986; ZMBN 127292 (~25 spec.), 63°42.7'N, 00°09.7'W, 2259 m, 17 Aug 1986; ZMBN 127293 (~25 spec.), 63°35.1'N, 00°06.0'W, 2150 m, 17 Aug 1986; ZMBN 127294 (~50 spec.), 62°41.5'N, 01°45.4'E, 750 m, 17 Aug 1986; ZMBN 127291 (7 spec.), 63°28.8'N, 00°14.5'E, 1957 m, 16 Aug 1986; ZMBN 127306 (3 spec.) Aktivneset, 62°44.89'N, 3°1.98'E, 569 m, 24.09.2013; ZMBN 127314 (~20 spec.), 63°2.23'N, 4°41.34'E, 760 m, 30 Sep 2013.

Diagnosis.

Body ellipsoid, flattened dorsoventrally, up to 3 mm long. Body unpigmented; orange macrotubercles in live specimens, or brownish in fixed material. Head appendages smooth and digitiform. Tentacular cirri smaller than prostomial appendages. Dorsum with four longitudinal rows of large, spherical or pear-shaped sessile macrotubercles in a single transverse row per segment, from segment 2. Additional papillae on dorsum. First parapodia short and digitiform, with two rounded papillae on dorsal surface. Acicular lobe from segment 1. Eight to ten parapodial papillae. Ventral cirri digitiform shorter than acicular lobe tip. About eight compound chaetae with medium length blades (ca. ten times as long as wide); unidentate.

Description of specimens from the Nordic Seas.

Measurements and general morphology. Ellipsoid body, flattened dorsoventrally, up to 2.8 mm long, mm 0.6 wide and with up to 20 chaetigers. Segmentation not conspicuous. Live specimen with some orange granules in macrotubercles (Fig. 8D, E), brownish in fixed material.

Head. Head fused to first chaetiger (Figs 8D, 20A). Palps and lateral antennae conical, near five times longer than wide, lacking spurs or basal papilla (Fig. 20 A–C). Median antenna conical, shorter than lateral antennae (Fig. 20 A–C). Antenniform papillae present (Fig. 20B). Approximately 8-10 papillae confined by prostomial appendages. Tentacular cirri digitiform, similar to lateral antenna (Fig. 20B).

Tubercles. Medium-sized dorsal macrotubercles arranged in four longitudinal rows, one transverse row per segment, with exception of first chaetiger with only two macrotubercles (Figs 8D, E, 20A, B). Macrotubercles sessile, spherical and smooth in anterior segments, and pear-shaped in posterior segments (Figs 8D, 20A). Distance between dorsalmost rows is larger than these to lateralmost longitudinal rows (Figs 8D, 20A). Additional dorsal papillae, spherical, arranged in about four irregular transverse rows per segment along dorsal surface, with ca. 20 papillae per segment, and in four transverse rows per segment in ventrum (Fig. 15K, L, 20D, E).

Parapodia. Parapodia conical, with acicular lobe from chaetiger 1 (Fig. 20G). Ventral cirri conical, not protruding from parapodia. Six or seven spherical parapodial papillae (two in anterior surface, two in ventral side, two in posterior side and one or two dorsally; Fig. 5O)

Chaetae. All chaetae compound, with unidentate and finely serrated blades 8-20 times longer than wide. Up to 18-20 chaetae per fascicle (Fig. 20G, J, L). One straight acicula per parapodium.

Pygidium. A pair of piriform anal cirri, similar to posterior macrotubercles and digitiform medio-ventral anal papilla.

Internal features. Eyes not seen. Muscular pharynx not evident in live and fixed material (e.g., Fig. 8D).

Reproductive features. The holotype seems to be a female with some eggs inside the coelom ( Fauvel 1911). Some females with oocytes (Fig. 8D); genital openings observed in females, between chaetigers 7 and 8 (Fig. 20 E, F).

Remarks.

The single type specimen of this species (in the Museum natural d’Histoire naturelle in Paris) is apparently lost, and the original description and drawings ( Fauvel 1911) are simple and inadequate to describe all characters. The median antenna is not mentioned by Fauvel (1911), indicating it is probably small and similar to other prostomial papillae. The shape and number of dorsal and epithelial papillae are not cited either. The number of parapodial papillae is not explicitly mentioned and has been interpreted differently in the literature (e.g., Fauchald 1974, Aguado and Rouse 2006, Shimabukuro et al. 2017). There is indication of S. philippi comb. n. bearing 10-11 parapodial papillae ( Fauchald 1974), or 20-22 parapodial papillae (e.g., Aguado and Rouse 2006, Shimabukuro et al. 2017). The first chaetigers bear at least two spherical dorsal papillae. According to original drawings, mid-body segments bear four dorsal parapodial papillae, and four are visible from the ventral side ( Fauvel 1911, Figs 18, 19). Ventral cirri do not protrude from the acicular lobe, although both are well developed.

Several of the specimens found and re-examined from museum collections had previously been identified as belonging to this species. However, they were misidentified in several cases, as there are other similar species in the North East Atlantic (as reported herein) and, as mentioned, different interpretation of the parapodial papillae and chaetal morphology according to previous records. The description and drawings by Hartmann-Schröder (1971) do not correspond to this species since the original drawings of S. philippi comb. n. indicate that blades of chaetae are long ( Fauvel 1911: Fig. 16) and these other records described, refer to or have illustrated short-blade chaetae.

The numerous specimens found from different localities in northern latitudes (and herein assigned to S. philippi comb. n.) resemble Sphaerephesia artabrensis comb. n. in the overall appearance, the shape and distribution of dorsal macrotubercles and dorsal and ventral papillae, the chaetal morphology, the presence and arrangement of sexual structures/genital pores ( Moreira and Parapar 2007). However, there are some consistent minor differences between the specimens examined from southern and northern localities. Specimens of S. artabrensis comb. n. are generally smaller (Iberian specimens are up to 1.75 mm long and Nordic specimens almost double in size), and bear a few more papillae in the prostomium, dorsum and parapodia (6-7 in specimens assigned to S. philippi comb. n., and 3-4 in S. artabrensis comb. n.). Specimens identified as S. philippi bear a well-developed acicular lobe from segment 1, instead of segment 2 as in members of S. artabrensis comb. n. ( Moreira and Parapar 2007).

It would therefore be most interesting to study in detail more material from intermediate localities (not found so far), as well as the genetic structures of these populations to test if they actually belong to a single lineage with a range of morphological features, or if the northern and southern forms (herein S. artabrensis comb. n. and S. philippi comb. n.) truly belong to separate species. Given that the types of S. philippi comb. n. from the Kara Sea are lost, and that the description of the species is not very detailed, it is not guaranteed that the broadly distributed lineage found in Nordic waters (e.g., Fig. 1) belongs to this species. However, based in the presence of acicular lobe from first segment (bifurcated in original description), approximate number of parapodial papillae, and chaetal morphology ( Fauvel 1911), we have opted for this possibility.

Distribution.

Arctic and Nordic Seas ( Fauvel 1911, present study).

Habitat.

Sediments, at shelf to slope depths ( Fauvel 1911, present study).