Polycirrus nogueirai, 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 : 172-174

Polycirrus nogueirai n. sp.

Figures 14–15 , Table 2.

Material examined: Holotype: MNHN-IA-TYPE 2016, incomplete, NE Atlantic, Bay of Biscay , Arcachon Bay, Jacquets, 44°43’21”N, 1°11’15”W, intertidal, December 2018 . Paratypes: AM W.53121, one incomplete specimen, NE Atlantic, Bay of Biscay , Arcachon Bay, Jacquets, 44°43’21”N, 1°11’15”W, intertidal, December 2018 , mounted for SEM. MNHN-IA-TYPE 2017, one incomplete specimen, NE Atlantic, Bay of Biscay , Arcachon Bay, Jacquets, 44°43’21”N, 1°11’15”W, intertidal, December 2018 . AM W.53122, one incomplete specimen, NE Atlantic, Bay of Biscay , Arcachon Bay, Jacquets, 44°43’21”N, 1°11’15”W, intertidal, December 2018 .

Description. Small species, holotype incomplete, 9.1 (4.5–11.0) mm long and 0.9 (0.6–0.8) mm wide.

Transverse prostomium attached to dorsal surface of base of upper lip; basal part as thick crest across dorsum, extending laterally, covering SG1 laterally and terminating lateral to lower lip. Buccal tentacles of two types, long and thin tentacles uniformly cylindrical, long and thick ones deeply grooved, with pointed tips ( Fig. 14 A–C). Peristomium forming lips; upper lip elongate, longer than wide, with a single median lobe only ( Figs 14B, D ; 15A ); lower lip rounded and inflated, as wide as long, very glandular and ridged ( Figs 14B, D ; 15A ).

SG1 and 2 reduced, SG1 visible dorsally, SG2 dorsally, laterally and ventrally ( Fig. 15A ); body with relatively uniform width until SG20, gently tapering after ( Fig. 14A, C ). Ventro-lateral inflated pads present from SG3 to SG13 (SG14), well-defined, smooth and transversely ridged until SG10, subsequent ones less conspicuous ( Figs 14 B–D; 15A). Midventral groove with small discrete shields from SG3 to SG10, continuing as a stripe until end of body ( Figs 14B, D ; 15A ).

Notopodia from SG3, extending for 16 (19–21) segments, until SG18 (SG21–23); distinctly elongate, rectangular, first pair slightly shorter, bilobed, postchaetal lobe digitiform, larger than prechaetal one ( Fig. 15B ). Winged notochaetae of two lengths, distal ends whip-like ( Figs 14E ; 15 B–C). Neuropodia beginning from SG14 (SG16); uncini with short occipitum and slightly convex base (Type 1) ( Fig. 14F ), 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. 15D ), absence of subrostral process ( Fig. 14F ).

Nephridial and genital papillae present on segments 3–8.

Pygidium unknown.

Etymology. This species is dedicated to João Nogueira for his great contribution to taxonomy of terebellids.

Habitat. Intertidal, muddy sands, sheltered waters.

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

Distribution. Only known from type locality.

Remarks. Polycirrus nogueirai n. sp. is characterized by the presence of notopodia on 16–21 segments, which is similar to P. glasbyi n. sp. (18–22 segments), P. plumosus (17–19 segments), P. readi n. sp. (13–17 segments), P. elisabethae (16 segments) and P. norvegicus (14–20 segments) ( Table 2). Among these species, only P. plumosus shows almost the same range in appearance of neuropodia (from SG18–22 for P. plumosus , from SG14–16 for P. nogueirai n. sp.).

However, P. nogueirai n. sp. differs from P. plumosus by the presence of one type of notochaetae only (instead of two for P. plumosus ), uncini with a median tooth in first row above main fang (absent for P. plumosus ), the shape of lower lip (protruding above venter and longer than wide for P. plumosus , rounded and as wide as long for P. nogueirai n. sp.) and by the shape of ventro-lateral pads (poorly defined for P. plumosus , inflated for P. nogueirai n. sp.).

Figures

FIGURE 14. Polycirrus nogueirai n. sp., holotype MNHN-IA-TYPE 2016 (A–C; F), paratype AM W.53121 (D), paratype MNHN-IA-TYPE 2017 (E). A. Entire specimen, lateral view; B. Anterior end, ventral view; C. Entire specimen, lateral view, methyl green; D. Anterior end, ventral view, methyl green staining; E. Notochaetae, SG10, 40x objective; F. Uncini, SG16, 40x objective. Abbreviations: BT, buccal tentacle; Ll, lower lip; Ul, upper lip. Numbers refer to segments.

FIGURE 15. Polycirrus nogueirai n. sp., SEM, paratype AM W.53121. A. Anterior end, ventral view; B. Notopodia, SG3, ventral view; Notochaetae, SG3; D. Thoracic uncini. Abbreviations: Ll, lower lip; Pcl, postchaetal lobe; Ul, upper lip. Numbers refer to segments.