Polycirrus idex, 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 : 169-170

publication ID	https://doi.org/ 10.11646/zootaxa.4869.2.1
publication LSID	lsid:zoobank.org:pub:50310045-52DE-4D53-AA0A-683D2FA87F5D
DOI	https://doi.org/10.5281/zenodo.4418234
persistent identifier	https://treatment.plazi.org/id/551BBCEA-7A0E-4FF4-B109-A7F8CFB6E5F5
taxon LSID	lsid:zoobank.org:act:551BBCEA-7A0E-4FF4-B109-A7F8CFB6E5F5
treatment provided by	Plazi
scientific name	Polycirrus idex
status	sp. nov.

Treatment

Polycirrus idex View in CoL n. sp.

Figure 12–13 View FIGURE 12 View FIGURE 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 GoogleMaps . 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 GoogleMaps 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 View FIGURE 12 A–B; 13A). Peristomium forming lips; upper lip elongate, longer than wide, with single median lobe only ( Figs 12 View FIGURE 12 B–C; 13A); lower lip oblong, slightly longer than wide, very glandular, ridged ( Figs 12C View FIGURE 12 ; 13A View FIGURE 13 ).

SG1 and 2 reduced, SG2 visible ventrally ( Figs 12C View FIGURE 12 ; 13A View FIGURE 13 ); body slightly broader until SG7. Ventro-lateral inflated pads well-defined from SG3 to SG9 (SG8), less defined on SG10 (SG9), smooth ( Figs 12C View FIGURE 12 ; 13A View FIGURE 13 ). Large anterior mid-ventral groove from S3, present until end of body as a stripe ( Figs 12C View FIGURE 12 ; 13A View FIGURE 13 ).

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 View FIGURE 18 ). Winged notochaetae in two rows ( Figs 12D View FIGURE 12 ; 13 View FIGURE 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 View FIGURE 13 ), subrostral process present as small tooth ( Fig. 13D View FIGURE 13 ).

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.).