Chaetocirratulus hessleri Blake 2022, new species

• Main Author: Blake, James A.
• Format: Other/Unknown Material
• Language: unknown
• Published: 2022
• Subjects: Biodiversity; Taxonomy; Animalia; Annelida; Polychaeta; Terebellida; Cirratulidae; Chaetocirratulus; Chaetocirratulus hessleri; North Atlantic
• Online Access: https://zenodo.org/record/6343001; https://doi.org/10.5281/zenodo.6343001

Chaetocirratulus hessleri new species Figures 8–9 urn:lsid:zoobank.org:act: 823AE4D8-8C7C-42A8-A423-A4FCA8EDC548 Chaetozone sp. B: Maciolek et al. 1987a: D-2 (in part). Material examined. Off New Jersey and Delaware, U.S. Mid-Atlantic ACSAR Program, coll. R. Petrecca, Chief Scientist. Sta. 3: Cruise Mid-2, Rep. 3, 03 Aug 1984, 38°36ʹ.84ʹN, 72°51.46ʹW, 2056 m, holotype (USNM 1660936). — Off New England, U.S. North Atlantic ACSAR Program, coll. G.W. Hampson, Chief Scientist. Sta. 3: Cruise NA-3, Rep. 1, 03 Jul 1985, 41°01.37ʹN, 66°21.21ʹW, 1337 m, paratype (USNM 1660937). Description. A large species, holotype complete, with 90 setigers, 40 mm long and 3 mm wide across anterior setigers. Body elongate, not inflated along body but gradually narrowing in far posterior segments. Parapodia located laterally along body with intersegmental grooves not apparent in anterior setigers and only weakly so in posterior segments; dorsal surface elevated above parapodia, rounded and relatively smooth (Fig. 8A); venter similarly flattened, also lacking distinct intersegmental grooves in first half of body; distinct intersegmental grooves only apparent laterally between anterior parapodia. Dorsal and ventral grooves absent but with a narrow white line along venter, probably representing ventral nerve cord extending from posterior margin of peristomium posteriorly along most of body. Color in alcohol tan in first half of body, grey in posterior half. Distinct areas of dark, dusky pigment apparent on ventral surface of peristomium posterior to mouth and first two setigers, extending higher on sides; same pigment present on posterior border of first 4–5 parapodia (Fig. 9A, C–D). Pre-setiger region about as wide as long. Prostomium broadly triangular, tapering to rounded apex (Fig. 8A); eyespots absent; nuchal organs at posterior lateral margins, mostly hidden by peristomium. Peristomium with three rings (Figs. 8A, 9A, C); first ring surrounding prostomium dorsally and forming posterior lip of mouth ventrally (Fig. 9A, D); second and ...