Streblosoma lindsayae, Lavesque & Londoño-Mesa & Daffe & Hutchings, 2020

Lavesque, Nicolas, Londoño-Mesa, Mario H., Daffe, Guillemine & Hutchings, Pat, 2020, A revision of the French Telothelepodidae and Thelepodidae (Annelida Terebelliformia), with descriptions of three species and first European record of a non-indigenous species, Zootaxa 4810 (2), pp. 305-327 : 315

Streblosoma lindsayae n.sp.

Figure 6

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Material examined: Holotype: MNHN-IA- type 1999, one specimen, incomplete, Northern Bay of Biscay , B3_ APP1, 47°31’27”N 3°27’02”W, 52 m depth, May 2018, some parapodia mounted for SEM.

Description. Holotype incomplete (26 segments), 17 mm long, 3.1 mm wide.

Transverse prostomium attached to dorsal surface of upper lip; basal part with eyespots regularly arranged in a single continuous row all around the surface. All buccal tentacles lost. Peristomium forming lips; upper lip hoodlike, convoluted, broader than high ( Fig. 6C ); lower lip short, rounded, covered by expanded lobe derived from SG1, lobe broader than high ( Fig. 6C ). SG1 large, visible dorsally and ventrally ( Fig. 6C ). Presence of a ventral crest on SG1 and short lateral crest on SG2–3 ( Fig. 6C ).

Two pairs of branchiae, on SG2–3, SG2 with 9–10 filaments on either side and SG3 with 7–9 filaments on either side ( Fig. 6 A–B); branchial filaments thin, originating dorsally to notopodia, arising directly from body wall, with wide medial gap ( Fig. 6 A–B); longest filaments about as long as width between left and right notopodia ( Fig. 6–B ). Anterior ventral surface strongly glandular from SG3 to about SG14, ventral shields absent ( Fig. 6C ), mid-ventral stripe visible from about SG16 to posterior end (SG26, incomplete).

Notopodia from SG2 ( Fig. 6 A–C) to posterior end; first pair of notopodia same size as following ones; first 12 notopodia oriented dorsally, moving progressively to a lateral position ( Fig. 6 A–C); notopodia small, roughly rectangular, distally rounded, bilobed with notochaetae arising between lobes. Notochaetae in two rows, increasing in length from ventral to dorsal position. Notopodia with bilimbate capillaries, those from posterior row longer, with well-developed wings, capillaries from anterior row shorter with fine tips ( Fig. 6D ).

Neuropodia from SG5, first pairs as fleshy ridges, slightly raised from posterior part of body. Uncini in straight rows until end of the body (SG26). Uncini with two rows of secondary teeth above the main fang, basal row with two teeth, second row with irregularly sized teeth; dorsal button close to anterior margin and longer than the prow, short triangular heel present, base curved; uncini longer than high ( Fig. 6 D–E).

Nephridial and genital papillae not visible. Pygidium unknown.

MG pattern. Ventral colouration until SG14, large blue dots on the dorsum, SG2–3 and ventral lobe of SG1 stained deeply. Anterior part of neuropodia blue ( Fig. 6 A–C).

Etymology. This species is named after Sue Lindsay from Macquarie University (Sydney), an amazing SEM technician who took hundreds of pictures for us and in recognition of her skills and her friendship.

Habitat. Muddy sands, 52 m depth.

Type locality. Northern Bay of Biscay , NE Atlantic .

Distribution. Only known from the type locality.

Remarks. The description of this new species is based on an incomplete holotype. However, as this specimen has only two pairs of branchiae, it differs from all other known European species. This character is sufficient to describe this species as new and most of the important diagnostic characters for the genus are present on this specimen.

Figures

FIGURE 6. Streblosoma lindsayae n. sp., MNHN-IA- type 1999 A. Anterior end, dorso-lateral view, MG staining; B. Anterior end, dorsal view, MG staining; C. Anterior end, ventral view, MG staining; D. Notopodia, CH6, SEM. E. Uncini, CH23. F. Uncini, CH26, SEM. Abbreviations: Br1, first pair of branchiae; Br2, second pair of branchiae; Ul, upper lip; Ll, lower lip; Vl, ventral lobe derived from SG1. Numbers referring to segments.