Chaetozone cristata Blake 2018, new species

• Main Author: Blake, James A.
• Format: Other/Unknown Material
• Language: unknown
• Published: 2018
• Subjects: Biodiversity; Taxonomy; Animalia; Annelida; Polychaeta; Terebellida; Cirratulidae; Chaetozone; Chaetozone cristata; Antarctic; Antarctic Peninsula; King George Island; South Shetland Islands; Gerlache; Anvers; Anvers Island; Gerlache Strait; Palmer Archipelago; Ryswyck; Ryswyck Point; Antarc*
• Online Access: https://zenodo.org/record/3798500; https://doi.org/10.5281/zenodo.3798500

Chaetozone cristata new species Figures 45–46 Chaetozone sp. 3: Hilbig 2001: 540 (in part); Hilbig et al. 2006: 715, 717, 719, 724 (in part). Material examined. West Antarctic Peninsula, Palmer Archipelago, Gerlache Strait, R / V Hero Sta. 824-25-1, 23 Mar 1982, 64.253°S, 61.458°W, trawl, 540–605 m, 1 paratype (USNM 1490773); Sta. 824-25-2, 24 Mar 1982, 64.348°S, 61.592°W, VV grab, 92 m, holotype (USNM 1490771) and 7 paratypes (USNM 1490772); Anvers Island, Ryswyck Point, R / V Hero, Sta. 824-32-1, 25 Mar 1982, 64.625°S, 62.853°W, Blake trawl, 640-670 m, 2 paratypes (USNM 1490774).— South Shetland Islands, off King George Island, R / V Polarstern, EASIZ II (ANT-XV/3), coll. B. Hilbig, Sta. 48-299, 14 Mar 1998, 62°15.8ʹS, 58°42.7ʹW, MG, 207 m, 11 specimens (SMF 24933). Description. A moderate-sized species, holotype complete, 14 mm long, 0.8 mm wide with approximately 100 setigerous segments; paratypes 12–18 mm long, 0.7–0.8 mm wide, with 90–107 setigerous segments. Body elongate, widest in anterior segments, gradually narrowing posteriorly; anterior segments about ten times as wide as long; middle body segments about twice as wide as long; posterior setigers narrowing, about three times as wide as long near posterior end, not moniliform. Dorsum rounded, without groove or ridge; venter somewhat flattened, with prominent mid-ventral groove from anterior through posterior segments (Fig. 46 C–D). Color in alcohol distinctly light tan, no additional pigment apparent anywhere on body. Prostomium triangular, narrowing apically to pointed tip (Figs. 45A, 46 A–C); eyespots absent; nuchal organs deep notches on posterior lateral margin (Fig. 46C). Peristomium with three more-or-less distinct annular rings surmounted by rounded, grooved dorsal crest (Figs. 45A, 46 A–B); grooves best seen dorsally; peristomium followed by an achaetous segment (Fig. 45A). Dorsal tentacles arising from groove between last peristomial ring and achaetous segment (Fig 45A). First pair of branchiae lateral and slightly posterior to tentacles on ...