Polycirrus gujanensis, Lavesque & Hutchings & Daffe & Londoño-Mesa, 2020

Lavesque, Nicolas, Hutchings, Pat, Daffe, Guillemine & Londoño-Mesa, Mario H., 2020, Revision of the French Polycirridae (Annelida, Terebelliformia), with descriptions of eight new species, Zootaxa 4869 (2), pp. 151-186 : 167-169

Polycirrus gujanensis n. sp.

Figures 10–11 , Table 2.

Material examined: Holotype: MNHN-IA-TYPE 2013, incomplete, NE Atlantic, Bay of Biscay , Arcachon Bay, Matelle, 44°39’51”N, 1°06’51”W, intertidal, May 2010, some parapodia mounted for SEM . Paratypes: MNHN-IA-TYPE 2014, one specimen, incomplete, NE Atlantic, Bay of Biscay , Arcachon Bay, Matelle, 44°39’51”N, 1°06’51”W, intertidal, May 2010. AM W.53119, one specimen, incomplete, NE Atlantic, Bay of Biscay , Arcachon Bay, Dispute, 44°42’17”N, 1°06’48”W, intertidal, August 2016. AM W.53120, one specimen, incomplete, NE Atlantic, Bay of Biscay , Arcachon Bay, Matelle, 44°39’51”N, 1°06’51”W, intertidal, May 2010, mounted for SEM .

Description. Large species, holotype incomplete (41 segments), 23.2 mm long and 2.2 mm wide.

Transverse prostomium attached to dorsal surface of base of upper lip; basal part as thick semicircular crest across dorsum, extending lateral and posteriorly ( Fig. 10D ), covering SG1 laterally and terminating lateral to lower lip. Buccal tentacles of two types, short tentacles uniformly cylindrical, long ones deeply grooved, with pointed tips ( Fig. 10 A–D). Peristomium forming lips; upper lip elongate, longer than wide, highly convoluted, folded into three lobes, lateral ones well-developed ( Figs 10B ; 11A ); lower lip oval and inflated, wider then long, very glandular and ridged ( Figs 10B ; 11A ).

SG1 and 2 reduced, only visible dorsally ( Fig. 10 C–D); body slightly broader until SG8, gently tapering until SG10, then of relatively uniform width, cylindrical, tapering posteriorly ( Fig. 10A ). Ventro-lateral inflated pads well-defined from SG3 to SG12, smooth and transversely ridged, subsequent ones less conspicuous until mid-body ( Figs 10 A–C; 11A). Deep midventral groove from SG3 to end of the body, with small discrete shields from SG3 to midbody ( Figs 10B ; 11A ).

Notopodia from SG3, extending for 28 segments, until SG30; distinctly elongate, rectangular, first two pairs slightly shorter, bilobed, postchaetal lobe larger than prechaetal one ( Fig. 11B ). Narrowly-winged notochaetae in two rows, with wings inconspicuous under light microscopy ( Figs 10E ; 11 B–C). Neuropodia beginning from SG15; uncini with short occipitum and slightly convex base (Type 1) ( Fig. 10F ), crest with single elongate and sharp tooth on first row above main fang, with two additional rows of shorter, irregularly sized teeth at base ( Fig. 11D ), subrostral process present as small tooth ( Fig. 10F ).

Nephridial and genital papillae present on segments 3–8, anterior and ventral to bases of notopodia.

Pygidium unknown.

Etymology. The species name refers to the city of Gujan-Mestras, off where the species was sampled.

Habitat. Intertidal, medium sands, sheltered waters.

Type locality. Arcachon Bay , Bay of Biscay, NE Atlantic Ocean, France .

Distribution. Only known type locality.

Remarks. Polycirrus gujanensis n. sp. is characterized by the presence of 28 pairs of notopodia, and neuropodia from SG15, which is different from all European species, excepting P. arenivorus (29 pairs of notopodia, neuropdia from SG12) ( Table 2). However, P. gujanensis n. sp. differs from this latter species by the shape of lower lip (oval and wider than long for P. gujanensis n. sp., oblong and longer than wide for P. arenivorus ), by the upper lip with three well-developed lobes (instead of medial lobe well developed only in P. arenivorus ) and by uncini with an elongate tooth above the main fang (this tooth absent in P. arenivorus ).

Figures

FIGURE 10. Polycirrus gujanensis n. sp., holotype MNHN-IA-TYPE 2013 (A–C; E–F), paratype MNHN-IA-TYPE 2014 (D). A. Anterior end, lateral view; B. Anterior end, ventral view; C. Anterior end, lateral view; D. Anterior part, dorsal view; E. Notochaetae, SG6, 10x objective; F. Uncini, SG17, 40x objective. Abbreviations: Bt, buccal tentacles; Ul, upper lip; Ll, lower lip; Sp, subrostral process. Numbers refer to segments.

FIGURE 11. Polycirrus gujanensis n. sp., SEM, paratype AM W.53120 (A–C), holotype MNHN_Arc_Poly_15 (D). A. Anterior end, ventral view; B. Notopodia, SG5, ventral view; Notochaetae, SG5; D. uncini, posterior parapodia. Abbreviations: Ll, lower lip; Ul, upper lip.