Lamispina amoureuxi, Salazar-Vallejo, 2014

Salazar-Vallejo, Sergio I., 2014, Revision of Pherusa Oken, 1807 (Polychaeta: Flabelligeridae), Zootaxa 3886 (1), pp. 1-61 : 41-42

Lamispina amoureuxi n. sp.

Figure 16

Ilyphagus sp. Amoureux, 1982:191 (partim).

Type material. Northeastern Atlantic Ocean. Holotype (MNHN 1557) and paratype (MNHN 1558), off SW Ireland, RV Thalassa, Cruise 1973, Sta. 447 (47°47'03" N, 11°12'00" W à 48°47'04" N, 11°14'03" W), 1200–1520 m, mud, Oct. 1973 (paratype anterior fragment, without tunic, dissected for anterior end details; 6.5 mm long, 3 mm wide, cephalic cage 3 mm long, 9 chaetigers; gonopodial lobes in chaetiger 5).

Additional material. One specimen (MNHN 477), juvenile without tunic, RV Thalassa, Cruise 1973, Sta. 440 (48°41'04" N, 10°21'05" W), 860 m, mud, Oct. 1973 . Three specimens (MNHN 477), an anterior and two medial fragments, damaged, RV Thalassa, Cruise 1973, Sta. 447 (47°47'03" N, 11°12'00" W à 48°47'04" N, 11°14'03" W), 1200–1520 m, mud, Oct. 1973 .

Description. Holotype (MNHN 1557) includes an anterior and a posterior fragment, apparently fitting together. Body with parallel sides, truncated at both ends, body wall pinkish, sediment cover whitish ( Fig. 16A, B ); 10+ 11 mm long, 3 mm wide, cephalic cage 3 mm long, 17+15 chaetigers. Tunic with large sediment particles, mainly foraminifera, completely covering body, with smaller tests laterally and ventrally. Papillae long, basally prismatic, darker, peduncle slightly capitate, arranged as two series per segment (one in first three chaetigers), placed along the same level as chaetal lobes, anterior series with 4–6 papillae, posterior series with 6–8 papillae; anterior series with less papillae in posterior segments. Segmentation indistinct due to foraminiferal cover.

Anterior end observed in paratype (Sta. 447). Cephalic hood short, margin smooth. Prostomium low; eyes not seen. Caruncle short, triangular. Palps thick, about 3 x as thick and darker than branchiae; palp lobes rounded, low. Lateral and dorsal lips reduced by compression; ventral lip not visible ( Fig. 16C ).

Branchiae arranged in a continuous row with four filaments, and two lateral groups each with two filaments. Nephridial lobes short, digitate, at the inner base of the proximal group of branchiae.

Cephalic cage chaetae as long as body width; chaetigers 1–2 forming cephalic cage. Chaetae arranged in two short groups, with four chaetae per ramus.

Anterior dorsal margin of first chaetiger papillose, papillae long, cirriform. Chaetigers 1–3 progressively larger, provided with long papillae. Chaetal transition from cephalic cage chaetae to body chaetae abrupt; lamispines present from chaetiger 2. Gonopodial lobes on chaetiger 5, globose, tips greyish ( Fig. 16D ).

Parapodia poorly developed, low transverse folds; more projected along first 5–6 chaetigers. Notopodia lateral, neuropodia ventrolateral. Notopodia with one long papilla, exposed over foraminiferal cover. Neuropodia projected lateral lobes with two long papillae, exposed above tunic.

Medial notochaetae multiarticulated capillaries, articles barely visible basally, few medial ones medium-sized, progressively longer distally ( Fig. 16E ); 3–4 per bundle, about as long as 1/3–1/2 body width. Neurochaetae multiarticulated capillaries in chaetiger 1; lamispines present from chaetiger 2, arranged in transverse series, 5–6 lamispines throughout the body; tips incurved, without hood ( Fig. 16F ).

Posterior end truncate; pygidium with anus dorsoterminal, papillose, without anal cirri ( Fig. 16G ).

Etymology. This species is named after Louis Amoureux, who made many significant contributions to polychaete systematics and especially because he studied the materials collected during the R.V. Thalassa cruises, including these specimens. The epithet is a noun in the genitive case.

Remarks. Lamispina amoureuxi n. sp. and L. keeli n. sp. diverge from other species in the genus because their tunics have large sediment particles. They differ from each other in the relative extent of sediment particles on their bodies, and on the start and type of lamispines. In L. amoureuxi sediment particles surround the body, its lamispines start in chaetiger 2, and their tips are entire, without accessory tooth, whereas in L. keeli sediment particles are restricted to the dorsal surface, its lamispines start in chaetiger 3, and their tips are bidentate with a distinct, long accessory tooth.

Type locality. Off Brest , France, in muddy bottoms at 1200–1520 m depth .

Distribution. Northeastern Atlantic Ocean, in the area off Brest, France and Southern Ireland, in muddy or mixed bottoms, at 860–1520 m depth.

Figures

FIGURE 16. Lamispina amoureuxi n. sp. A. Holotype (MNHN 1557), anterior fragment, ventral view. B. Same, anterior end, dorsal view. C. Paratype (MNHN 1558), head, frontal view, depressed by cover slip (branchiae and palps removed; BS: branchial scar, NL: nephridial lobe, PS: palp scar). D. Same, sediment particles removed, anterior region, ventral view (arrows point at gonopodial lobes). E. Same, chaetiger 9, notochaetae (insets: basal, transition, subdistal and tip). F. Same, chaetiger 9, lamispines (insets: basal, medial and distal regions plus tips of smaller lamispines). G. Holotype, posterior region, dorsal view. Scale bars: A: 1.6 mm, B: 0.6 mm, C: 0.2 mm, D: 0.8 mm, E: 0.3 mm, F: 0.4 mm, G: 0.5 mm.