Polycirrus idex Lavesque & Hutchings & Daffe & Londoño-Mesa 2020, n. sp.
Creators: name: Lavesque, Nicolas
name: Hutchings, Pat
name: Daffe, Guillemine
name: Londoño-Mesa, Mario H.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Polychaeta
Terebellida
Terebellidae
Polycirrus
Polycirrus idex

description: Polycirrus idex n. sp.
Figure 12–13, Table 2.
Material examined: Holotype: MNHN-IA-TYPE 2015, one complete specimen, Mediterranean Sea, Corsica Cape, 42°44’42”N, 9°28’00”E, 16 m depth, May 2019, posterior part used for molecular analysis. Paratype: AM W.53127, one complete specimen, Mediterranean Sea, Corsica Cape, 43°01’18”N, 9°24’30”E, 18 m depth, May 2019, mounted for SEM, posterior part used for molecular analysis.
Description. Small specimen 4.6 (4.3) mm long and 0.6 (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; distal part extending along upper lip, terminating subdistally. Buccal tentacles of two types, long grooved annulated and uniformly cylindrical ones, short thick grooved and distally enlarged ones (Figs 12 A–B; 13A). Peristomium forming lips; upper lip elongate, longer than wide, with single median lobe only (Figs 12 B–C; 13A); lower lip oblong, slightly longer than wide, very glandular, ridged (Figs 12C; 13A).
SG1 and 2 reduced, SG2 visible ventrally (Figs 12C; 13A); body slightly broader until SG7. Ventro-lateral inflated pads well-defined from SG3 to SG9 (SG8), less defined on SG10 (SG9), smooth (Figs 12C; 13A). Large anterior mid-ventral groove from S3, present until end of body as a stripe (Figs 12C; 13A).
Notopodia from SG3, extending for 13 (14) segments, until SG15 (SG16); not very elongate, rectangular, first pair slightly shorter, bilobed, postchaetal lobe conical with rounded tip, larger than prechaetal one (Fig. 18B). Winged notochaetae in two rows (Figs 12D; 13 B–C). Neuropodia beginning from SG8 (SG7); uncini with short occipitum and slightly convex base (Type 1), crest with single elongate and sharp tooth on first row above main fang, with one additional row of 4–5 short, irregularly sized teeth (Fig. 13D), subrostral process present as small tooth (Fig. 13D).
Nephridial and genital papillae not seen.
Pygidium rounded.
Etymology. This species is named after IDEX (Excellence Initiative of Bordeaux University), which funded two grants for NL and GD to spend 9 months at the Australian Museum (Sydney). “Idex” is an unmodifiable noun in apposition.
Habitat. 18 m depth, among rocks.
Type locality. Corsica Cape, Mediterranean Sea.
Distribution. Only known from type locality.
Remarks. With 14 segments with notopodia and neuropodia starting on SG7–8, P. idex n. sp. differs from all other European species (Table 2). The closest species is P. asturiensis (notopodia on 10 segments and neuropodia starting on SG6) but this last species has a trefoiled upper lip (instead of a single lobe only for P. idex n. sp.), a lower lip wider than long (instead of longer than wide for P. idex n. sp.) and uncini showing two rows of secondary teeth above the main tooth (instead of a single row of secondary teeth for P. idex n. sp.).
description: Published as part of Lavesque, Nicolas, Hutchings, Pat, Daffe, Guillemine & Londoño-Mesa, Mario H., 2020, Revision of the French Polycirridae (Annelida, Terebelliformia), with descriptions of eight new species, pp. 151-186 in Zootaxa 4869 (2) on pages 169-170, DOI: 10.11646/zootaxa.4869.2.1, http://zenodo.org/record/4418481