Streblosoma patriciae, Santos & Nogueira & Fukuda & Christoffersen, 2010

Santos, Andre Souza Dos, Nogueira, João Miguel De Matos, Fukuda, Marcelo Veronesi & Christoffersen, Martin Lindsey, 2010, New terebellids (Polychaeta: Terebellidae) from northeastern Brazil, Zootaxa 2389 (1), pp. 1-46 : 5-14

publication ID	https://doi.org/ 10.11646/zootaxa.2389.1.1
persistent identifier	https://treatment.plazi.org/id/8C6287D6-4314-FFE8-FF16-29703C46B3D4
treatment provided by	Felipe
scientific name	Streblosoma patriciae
status	sp. nov.

Treatment

Streblosoma patriciae View in CoL sp. nov.

( Figs 1–5 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 ; Table 1)

Material examined. Type series. Holotype MZUSP 01039: coll. Sta. 21 (05°05’03.1”S 36°27’18.9”W), 9 Nov 2007. Paratypes 1–3 coll. Sta. 20 (05°04’46.9”S 36°26’19.5”W), 8 Nov 2007; paratype 1 CIPY-POLY-

1384, paratype 2 CIPY-POLY-1385, paratype 3 CIPY-POLY-1386. Paratypes 4–7 coll. Sta. 23 (05°04’04”S 36°20’25”W), 10 Nov 2007; paratype 4 CIPY-POLY-1387, paratype 5 LACM-AHF POLY 2262, paratype 6 MZUSP 01040, paratype 7 MZUSP 01041. Paratypes 8–9 coll. Sta. 22 (05°05’12.9”S 36°28’03.8”W), 10 Nov 2007; paratype 8 ZMUC-POL-2105, paratype 9 LACM-AHF POLY 2255. For more information on each specimen of type-series see Table 1.

Additional material. Sta. 20 (05°04’46.9”S 36°26’19.5”W): 6 specs, 8 Nov 2007. Sta. 23 (05°04’04”S 36°20’25”W): 3 empty tubes, 10 Nov 2007.

Comparative material examined. Streblosoma acymatum Hutchings & Rainier, 1979 . Holotype ( AM W78 ), coll. Australia, New South Wales, Port Jackson (33°51'S 151°16'E), 1909; slides: neurochaetae from anterior and posterior region after notopodia terminate; 2 paratypes ( AM W5107 , AM W5108 ), coll. Australia, New South Wales, Charlotte Bay (32°20'S 152°33'E), Dec 1970; 1 paratype ( AM W5766 ), coll. Australia, New South Wales, Careel Bay GoogleMaps (33°37'S 151°19'E), in Posidonia , 6 Feb 1973; slides: notochaetae from segment 12; neurochaetae from segments 12 and from region after notopodia terminate; 2 non-type specs ( AM W22428), coll. Australia, New South Wales, Port Jackson GoogleMaps (33°52'24”S 151°10'30”E), Mar 1986; slides: notochaetae from segments 21 and 26.

Streblosoma hartmanae Kritzler, 1971 . Holotype ( USNM 43209 ) and 3 paratypes ( USNM 43210 ), coll. USA, Florida, Franklin County, 28 Dec 1969; holotype complete, all paratypes incomplete specs in good state of preservation; slides: holotype ( USNM 43209 ): notochaetae from segments 3 and 21; neurochaetae from segments 7, 22, 35 and posterior region after notopodia terminate.

Streblosoma nyanganus ( Augener, 1918) . Holotype ( ZMH: V1702 View Materials ) and 2 paratypes ( ZMH: V1707 View Materials ), coll. Gabon (Cape Lopez and Nyanga River), São Tomé and Príncipe (Ilhéu das Rolas) and Angola (Ambrizete); incomplete specimens in good state of preservation; slides: largest paratype ( ZMH: V1707 View Materials ): notochaetae from segments 9 and 27; neurochaetae from segments 9, 27, 84 and 90.

Streblosoma oligocirrus ( Schmarda, 1861) . Cotypes ( NMW 1630), many specimens and tubes in poor state of preservation; slides: largest cotype examined: notochaetae from segments 7 and 37; neurochaetae from segments 6 and 42; whole parapodium from segment 38.

Description. Thick tube, mucous, with coarse stones and fragments of shells embedded. Body 20–108 (60) mm long, 2.2–5.3 (3.9) mm wide, buccal tentacles 7–37 (17) mm long, complete specimens with 55–85 (73) segments ( Table 1). Preserved body uniformly light brown, without distinct patterns of pigmentation ( Figs 1A–K View FIGURE 1 ; 2A–I View FIGURE 2 ). Ventral surface highly glandular, discrete ventral shields absent, uniformly smooth ( Figs 1A–B, D–F, J–K View FIGURE 1 ; 3C–D, G–H View FIGURE 3 ) to corrugated between neuropodia ( Fig. 2B–D, F–I View FIGURE 2 ). Prostomium at base of upper lip; basal part of prostomium with broad band of small eyespots arranged in 2–3 transverse irregular rows, eyespots more numerous laterally and sparse, well separated from each other mid-dorsally ( Figs 1E–F, I–K View FIGURE 1 ; 2A–B, D–I View FIGURE 2 ); distal part of prostomium forming shelf-like process bearing numerous uniformly cylindrical buccal tentacles. Peristomium forming lips and complete ring around the body; upper lip short, hood-like, about as long as wide ( Figs 1A, E–F View FIGURE 1 ; 2C, F View FIGURE 2 ; 3D, H View FIGURE 3 ); lower lip narrow, relatively long and swollen ( Figs 1A, E–F, K View FIGURE 1 ; 2C–D, F, H–I View FIGURE 2 ; 3D, G–H View FIGURE 3 ); peristomium continuing dorsally as narrow annulation, with conspicuous nuchal organs as ciliated grooves on border with prostomium ( Figs 1E–F, I View FIGURE 1 ; 2A–B, D–I View FIGURE 2 ; 3C, F–G, J–L View FIGURE 3 ). Segment 1 short, ending ventro-laterally below lower lip or partially fused to it ( Figs 1A–F, I–K View FIGURE 1 ; 2A–I View FIGURE 2 ; 3A–D, F–H, J–L View FIGURE 3 ), distinction between lower lip and segment 1 unclear and strongly dependent on state of preservation of specimens. Segment 2 with protruding ventral crest covering posterior part of segment 1, midventrally indented by lower lip ( Figs 1A–B, D–F, J–K View FIGURE 1 ; 2B–D, F–I View FIGURE 2 ; 3C–D, G–H, J View FIGURE 3 ). Three pairs of branchiae, on segments 2–4, each with around 10–37 (22–24) thin independent filaments progressively tapering to tips, leaving narrow mid-dorsal gap between filaments from left and right sides within a pair ( Figs 1B–D, H–K View FIGURE 1 ; 2A–B, D–E, G–I View FIGURE 2 ; 3A–C, F–G, J–K View FIGURE 3 ); branchial filaments originating from swollen glandular areas, those on segment 2 located anteriorly to notopodia, those on segments 3 and 4 arranged in semicircles located dorsally and posteriorly to notopodia ( Figs 2A–B, D–E, G–I View FIGURE 2 ; 3A–C, F–G, J–K View FIGURE 3 ); all pairs with similar number of branchial filaments ( Table 1); branchial filaments arranged in 2–3 rows, those on segment 2 inserted close to anterior margin of segment and extending laterally beyond level of notopodia, those of other segments inserted from mid-length of segments ( Figs 1B–D, H–K View FIGURE 1 ; 2A–B, D–E, G–I View FIGURE 2 ; 3A–C, F–G, J–K View FIGURE 3 ). Notopodia extending until segment 30–36 (30) ( Table 1), notopodia on segment 2 about same size as following ones, notopodia on segment 3 lateralmost, on segments 2, 4–5 inserted progressively more dorsally, then vertically aligned ( Figs 1J–K View FIGURE 1 ; 2A–B, D–E, G–I View FIGURE 2 ; 3A–C, F–G, J View FIGURE 3 ). Notochaetae of both tiers as slightly geniculate, winged capillaries, with wings broader on one side, but narrower than width of shaft, those on anterior tier much longer than those on posterior tier, with wings starting from distal half, chaetae from posterior tier with basally bulbous wings ( Figs 4A, D View FIGURE 4 ; 5A–C View FIGURE 5 ). Neuropodia as fleshy ridges on region with biramous parapodia ( Figs 1A–F, H, J–K View FIGURE 1 ; 2B–D, F–H View FIGURE 2 ; 3B–D, F–H View FIGURE 3 ), progressively broader until segment 11, about same width on segments 11–15, then progressively narrower until segment on which notopodia terminate; neuropodia of region after notopodia terminate as short cylindrical pinnules ( Figs 1G View FIGURE 1 ; 3I View FIGURE 3 ). Uncini with elongate base, almost terminal dorsal button, prow reduced to short knob and main fang surmounted with two rows of secondary teeth ( Figs 4B–C, E–F View FIGURE 4 ; 5D–I View FIGURE 5 ); first row of secondary teeth with 1–3 teeth, usually 2, and second row, on anterior segments, with 1–2 minute teeth between teeth of anterior row, only visible under SEM ( Fig. 5D–F View FIGURE 5 ), with more teeth from midbody segments, with larger tooth between teeth on first row ( Figs 4E–F View FIGURE 4 ; 5G–I View FIGURE 5 ). Nephridial and genital papillae present on segments 4–7, inserted posteriorly to notopodia, papillae on segments 4–5 slightly shorter ( Figs 1J–K View FIGURE 1 ; 2A–B, D–E, G–I View FIGURE 2 ; 3B–C, F–G View FIGURE 3 ). Pygidium smooth ( Figs 1G View FIGURE 1 ; 3E View FIGURE 3 ).

Variation. The specimens examined present great variation in the number of branchial filaments and this character seems to be size-dependent ( Table 1), but the glandular areas from which branchial filaments emerge are conspicuous in all specimens and a mid-dorsal gap between filaments of left and right groups within a pair is always present.

Remarks. Streblosoma patriciae sp. nov., belongs to a group of few species of thelepodines with branchial filaments originating from swollen glandular areas, instead of directly from the body wall. Although this character is likely to be homoplastic, with species currently assigned to different genera presenting it, it may be significant.

According to the literature, only three other species of thelepodines have branchial filaments originating from swollen glandular areas instead of directly from the body wall, Pseudostreblosoma brevitentaculatum Nogueira & Alves, 2006 , Thelepus robustus ( Grube, 1878) (according to Hutchings & Glasby 1987 and our own observations) and Streblosoma acymatum Hutchings & Rainier, 1979 . However we have noticed that Streblosoma nyanganus ( Augener, 1918) also has this character.

Streblosoma acymatum differs from S. patriciae sp. nov., in having a more corrugated ventral surface of anterior segments, fewer pairs of notopodia, 25–29, instead of 29–35 pairs, more branchial filaments on the first branchiferous segment, forming a continuous row across dorsum, while in S. patriciae sp. nov., a medial gap is conspicuous, and nephridial and genital papillae situated between noto- and neuropodia, while in S. patriciae sp. nov., they are inserted posterior to notopodia (see Hutchings & Glasby 1987).

Streblosoma nyanganus is morphologically more similar to S. patriciae sp. nov., than any of the other species discussed below. This species was described from Western Africa, as the type-species of the newly erected genus Pseudothelepus Augener, 1918 , but it was later considered as a possible synonym of S. oligocirrus ( Schmarda, 1861) by Hartman (1959), although Pseudothelepus was still considered as a valid genus. Our observations of type material of S. nyanganus and S. oligocirrus showed that these taxa are separate species, and both are species of Streblosoma . Formal redescriptions of both these taxa will be published elsewhere (Nogueira et al. in prep.), but for the purpose of this paper it is important to differentiate S. nyanganus from S. patriciae sp. nov. Streblosoma nyanganus is distinguished from S. patriciae sp. nov., in having much shorter buccal tentacles, barely reaching beyond level of the anterior end, a slightly different arrangement of the swollen glandular areas from which the buccal tentacles arise, a larger number of pairs of notopodia associated with a shorter body, 40–42 pairs in specimens up to 79 mm long, against 29–35 in specimens up to 108 mm long, as in S. patriciae sp. nov., and uncini of the posterior part of region after notopodia terminate with 3 rows of secondary teeth, subterminal dorsal button and a longer prow.

As said above, prior to the present study, three species of Streblosoma have been recorded from the Brazilian coast, S. oligobranchiatum Nogueira & Amaral, 2001 and S. porchatensis Nogueira, Garraffoni & Alves, 2004 , which are only known from the State of São Paulo, and S. bairdi ( Malmgren, 1866) , with a wider distribution, from the State of São Paulo to Alagoas. In addition, three other species are known from the Caribean, which is relatively close to Rio Grande do Norte, S. hartmanae Kritzler, 1971 , described from Florida, USA, S. oligocirrus , described from Jamaica, and S. polybranchia Verrill, 1900 , from Bermuda.

Streblosoma bairdi was originally described from the Swedish coast and, although its occurrence in Brazil is unlikely, it has been recorded by Nonato & Luna (1970), Rullier & Amoureux (1979) and Morgado & Amaral (1989). That material is not available for study, but Nonato & Luna (1970) provided a description of the Brazilian specimens and, according to these authors, it is another small species, up to 42 mm, and with fewer branchial filaments, around 3–8 filaments on each side of the pairs, against ~10–37 filaments as in S. patriciae sp. nov. In addition, Nonato & Luna (1970) state that their specimens have neuropodia beginning from the third branchial segment (segment 4), but this is unlikely to occur in a species of Streblosoma .

Streblosoma oligobranchiatum and S. porchatensis are much shorter species than S. patriciae sp. nov., S. oligobranchiatum reaches up to 10 mm in length and S. porchatensis up to about 40 mm. In addition, S. oligobranchiatum has markedly fewer branchial filaments, 1–3 filaments on each side of the pair on segment 2 and 0–1 filament on each side of the pairs on segments 3–4, fewer pairs of notopodia, up to 23 pairs, notochaetae from posterior tier broadly-winged, instead of narrowly-winged, as in S. patriciae sp. nov., and inconspicuous nephridial and genital papillae, instead of conspicuous papillae on segments 4–7, as in S. patriciae sp. nov. (see Nogueira & Amaral 2001; Nogueira et al. 2004).

Streblosoma porchatensis also has fewer branchial filaments than S. patriciae sp. nov., notopodia extending until close to pygidium, and uncini characteristically arranged in curved, C-shaped rows for most of body segments, instead of in single straight rows, as in S. patriciae sp. nov. (see Nogueira et al. 2004).

In addition to having branchial filaments originating directly from the body wall, instead of from swollen glandular areas, S. hartmanae is also smaller, the holotype reaching around 50 mm in length, 1 mm in width, the paratypes even shorter, it also has fewer branchial filaments than S. patriciae sp. nov., broadly-winged notochaetae, especially on posterior notopodia, and nephridial papillae inserted between parapodial lobes.

Streblosoma oligocirrus also has branchial filaments originating directly from the body wall and is much shorter than S. patriciae sp. nov., with more pairs of notopodia, longest cotype examined ~ 35 mm long, with 41 pairs of notopodia. In addition, it has branchial filaments in all pairs of branchiae inserted anteriorly to notopodia, with fewer filaments, 10–15 filaments on first pair of branchiae, ~ 10 in both second and third pairs, with distinctly wider mid-dorsal gap between filaments from left and right sides in all pairs, and nephridial papillae inserted between parapodial lobes.

Finally, S. polybranchia is an unusual species of Streblosoma , for having lateral lobes on segments 1 and 2 and branchiae on segments 2–6, according to the original description ( Verrill 1900). In addition, S. polybranchia differs from S. patriciae sp. nov., because it has 44 pairs of notopodia with a much shorter body, ~ 40 mm long.

Etymology. We dedicate this species to Dr Patricia A. Hutchings, from the Australian Museum, not only for her friendship with one of us (JMMN), but also as recognition of a researcher who has studied the taxonomy and the relationships within the Terebellidae for more than 30 years.