Polycirrus catalanensis Lavesque & Hutchings & Daffe & Londoño-Mesa 2020, n. sp.

Polycirrus catalanensis n. sp.

Figures 4–5, Table 2.

Material examined: Holotype: MNHN-IA-TYPE 2007, one complete specimen, Mediterranean Sea, Gulf of Lion, Reserve St Troc, 42°29’01”N, 3°08’48”E, 31 m depth, 2017. Paratypes: AM W.53112, one complete specimen, Mediterranean Sea, Gulf of Lion, Reserve St Troc, 42°29’01”N, 3°08’48”E, 31 m depth, 2017. MNHN-IA-TYPE 2008, two complete specimens, Mediterranean Sea, Gulf of Lion, Reserve St Troc, 42°29’01”N, 3°08’48”E, 31 m depth, 2017. AM W.53113, one complete specimen, Mediterranean Sea, Gulf of Lion, Reserve St Troc, 42°29’01”N, 3°08’48”E, 31 m depth, 2017, mounted for SEM.

Description. Small species, holotype 11.5 (6.2–7.8) mm long and 0.5 (0.3–0.7) mm wide.

Transverse prostomium attached to dorsal surface of base of upper lip; basal part as thick crest across dorsum, extending laterally and dorsally, covering SG1 laterally and terminating lateral to lower lip. Buccal tentacles lost. Peristomium forming lips; upper lip, longer than wide, not elongated, with a single median and very thick convoluted lobe only (Figs 4 A–D; 5A); lower lip rectangular with rounded corners, longer than wide, very glandular and ridged (Figs 4 A–D; 5A).

SG1 and 2 reduced, SG1 visible dorsally, SG2 visible dorsally and laterally (Fig. 4C); body slightly broader until SG6, mid-body inflated, posterior part tapering (Fig. 4 A–B, D). Ventro-lateral inflated pads present from SG3 to SG10, well-defined (Figs 4 A–D; 5A). Anterior mid-ventral groove present from SG3 (Figs 4D, 5A).

Notopodia from SG3, extending for 15 (13) segments, until SG17 (SG15); distinctly elongate, rectangular, first two pairs slightly shorter, bilobed, postchaetal lobe digitiform, larger than prechaetal one (Fig. 5 A–B). Narrowly winged notochaetae in two rows, distal ends whip-like (Fig. 5 B–C), with wings inconspicuous under light microscopy (Fig. 4E). Neuropodia from SG17 (SG15–16); uncini with short occipitum and slightly convex base (Type 1) (Fig. 4F), crest with single row of secondary teeth, with a sharp elongate central tooth almost reaching tip of main fang, and two small lateral teeth on each side (Fig. 5D), subrostral process present as low protuberance (Fig. 4F).

Nephridial and genital papillae not seen.

Pygidium rounded with pointed tip (Fig. 4D).

Etymology. Species name refers to the Catalan Sea (north-western Mediterranean), where the species was found.

Habitat. Coastal heterogeneous sands, 30 m depth.

Type locality. Banyuls-Cerbere natural reserve, Catalan Sea, Mediterranean Sea, France.

Distribution. Only known from type locality.

Remarks. Polycirrus catalanensis n. sp. is characterized by the presence of notopodia extending over 13–15 segments which is similar to P. denticulatus (12–13 segments), P. pennarbedae n. sp. (12–13 segments) and P. norvegicus (14–20 segments) (Table 2). Among these species, only P. pennarbedae n. sp. shows almost the same range in the first appearance of neuropodia (from SG15–16 for P. pennarbedae n. sp., from SG15–17 for P. catalanensis n. sp.) (Table 2).

However, P. catalanensis n. sp. differs from P. pennarbedae n. sp. by the shape of uncini (two rows of teeth above the main tooth and the absence of subrostral process for P. pennarbedae n. sp., a single row of secondary teeth above the main tooth and the presence of subrostral process for P. catalanensis n. sp.), the shape of upper lip (elongated triangular medial lobe for P. pennarbedae n. sp., very thick single medial lobe for P. catalanensis n. sp.), the shape of lower lip (oval and wider than long for P. pennarbedae n. sp., rectangular and longer than wide P. catalanensis n. sp.) and the presence of a large mid-ventral grove on anterior segments for P. catalanensis n. sp. (not visible for P. pennarbedae n. sp.) (Table 2).

Polycirrus catalanensis n. sp. differs from P. denticulatus by the first appearance of neuropodia (from SG15–17 for P. catalanensis n. sp., from S12 for P. denticulatus), by he shape of lower lip (rectangular for P. catalanensis n. sp., subtriangular, pointing toward mouth for P. denticulatus), the shape of notochaetae (with wings inconspicuous for P. catalanensis n. sp., subdistally expanded for P. denticulatus following Glasby & Hutchings, 2014) and dental formula of uncini (MF:3 for P. catalanensis n. sp., MF:1: α for P. denticulatus).

Another species occurring in the French Mediterranean Sea, P. medusa, differs from P. catalanensis n. sp. by the presence of notopodia on 12 segments (instead of 13–15 for P. catalanensis n. sp.), by the type of notochaetae (absence of pinnate chaetae for P. catalensis n. sp., but present for P. medusa), by uncini with complete transverse series of secondary teeth above main tooth (instead of a crest with a very long tooth and two small lateral teeth for P. catalanensis n. sp.), by the presence of trefoiled upper lip with thin margin (instead of upper lip with single medial lobe with thick margin for P. catalanensis n. sp.) and by the presence of a subtriangular lower lip, pointing towards the mouth (instead of a rectangular one for P. catalanensis n. sp.) (Table 2).