Leodamas hyphalos Blake, 2017, new species

• Main Author: Blake, James A.
• Format: Other/Unknown Material
• Language: unknown
• Published: 2017
• Subjects: Biodiversity; Taxonomy; Animalia; Annelida; Polychaeta; Orbiniidae; Leodamas; Leodamas hyphalos; Drake Passage
• Online Access: https://zenodo.org/record/4901785; https://doi.org/10.5281/zenodo.4901785

Leodamas hyphalos new species Figures 33–34 Scoloplos (Leodamas) spp. Hartman 1967: 108 (in part). Material examined. Drake Passage, Eltanin Sta. 4-112, 20 Jul 1962, 56.03°S, 61.93° W, 4008 m, 13 paratypes ( USNM 56456); Sta. 4-126, 29 Jul 1962, 57.20°S, 62.75°W, 3733–3806 m, holotype (USNM 1013904); and 13 paratypes (USNM 56457); Sta. 4-155, 17 Aug 62, 56.52°S, 63.25°W 3927 m, 7 paratypes (USNM 56458); R/V Polarstern, ANDEEP I, Sta. PS-61/043-2, 3958 m (1, SEM, JAB); PS-61/046-3, 2888 m (1, SEM, JAB). Description. Majority of specimens small, incomplete; holotype 5.5 mm long and 0.7 mm wide for 29 setigers; largest paratype 9.0 mm long and 0.6 mm wide for 34 setigers. A single, much larger incomplete specimen from ANDEEP I Sta. PS-61 046-3 broken into two parts with 82 setigers, measuring 36 mm long and 3 mm wide across thorax. Color in alcohol: light brown. Thoracic region with 16–18 setigers, inflated in first 3–4 setigers (Fig. 33 B), subsequent thoracic setigers depressed; transition to abdominal region gradual, with last three thoracic setigers having fewer setae (Fig. 33 C). Intersegmental annulations first present from setigers 8–9; these weakly developed, never prominent (Fig. 33 A). Branchiae from setiger 6 (Figs. 33 A, 34A); thoracic and anterior abdominal branchiae basally inflated (Figs. 33 A, 34A), subsequent abdominal branchiae expanded (Fig. 33 J); branchiae absent from far posterior setigers. Prostomium triangular in outline, pointed on anterior margin (Figs. 33 A, 34A); eyespots absent; nuchal organs in SEM as transverse slits at border of prostomium and peristomium (Fig 34 A); proboscis divided into 3–4 lobes (Fig. 34 A). Peristomium with one short achaetous ring (Figs. 33 A, 34A). Thoracic notopodia with minute postsetal lamellae on setigers 1–2, barely seen in SEM (Fig. 33 A), becoming larger more visible from setiger 3 (Fig. 33 A), short at first, then elongating, becoming unusually long, fingerlike structures (Figs. 33 A–C, 34A), continuing through abdominal region. Thoracic neuropodia ...