Caulleriella fimbriata Blake 2018, new species

• Main Author: Blake, James A.
• Format: Text
• Language: unknown
• Published: Zenodo 2018
• Subjects: Biodiversity; Taxonomy; Animalia; Annelida; Polychaeta; Terebellida; Cirratulidae; Caulleriella; Caulleriella fimbriata; Antarctic; Southern Ocean; Weddell Sea; Weddell; Fang; Diaz; Noto; Powell Basin; Antarc*; Antarctica
• Online Access: https://dx.doi.org/10.5281/zenodo.3798605; https://zenodo.org/record/3798605

Caulleriella fimbriata new species Figure 23 Material examined. Southern Ocean, Powell Basin , R / V Polarstern , ANDEEP III (ANT-XXII/3), Sta. 67/150-8, 20 Mar 2005, 61°48.56ʹS, 47°27.48ʹW, MUC, 1884 m, holotype (SMF 24908). Description . Holotype small, threadlike, complete in three pieces, 3.4 mm long, 0.1 mm wide, with 60 setigerous segments. Body cylindrical throughout, without dorsal and ventral grooves; anterior segments to about setiger 14 wider than long (Fig. 23A), then becoming rounded, moniliform in middle body, becoming narrow again in far posterior segments; body tapering to triangular pygidium bearing a single anal cirrus (Fig. 23B). Parapodia of first four setigers close to one another, then these separating with noto- and neuropodia becoming widely separated from one another along rest of body (Fig. 23A). Color in alcohol tan with diffuse brown pigment on a few anterior segments. Prostomium triangular, tapering to rounded tip; with rounded dome-like dorsal crest with glandular band on posterior margin (Fig. 23A); eyespots absent; nuchal organs narrow slits anterior to band of glands (Fig. 23A). Peristomium enlarged, inflated, about as long as first three setigers, without annular rings (Fig. 23A); with two short lobes representing stumps of dorsal tentacles near posterior margin (Fig. 23A). First pair of branchiae on setiger 1 posterior to notosetae; subsequent branchiae from same location, continuing to about setiger 20. Parapodia reduced to simple mounds from which setae arise. Notosetae include 4–6 simple capillaries on first 15–20 setigers; bidentate hooks from setiger 23, with 3–4 hooks and 1–2 thin capillaries per notopodium continuing to posterior end; last 1–2 notopodia with hooks long, acicular, lacking apical tooth. Neurosetae include 3–4 capillaries on setigers 1–5, with bidentate hooks from setiger 6; hooks 2–3 per neuropodium accompanied by 1–2 capillaries. Hooks gently curved, with short, pointed apical tooth surmounting sharply pointed main fang (Fig. 23C); hooks without hood or crest on shaft. Etymology . The epithet is from fimbria , Latin for thread, referring to the threadlike body of this species. Remarks . Caulleriella fimbriata n. sp. , C. antarctica , and C. kacyae n. sp. are three small, threadlike species that all occur in deep-water Antarctic sediments. Caulleriella fimbriata n. sp. is distinguished from the other two species in having only a single peristomial ring instead of two or three, and a single anal cirrus instead of two. Additional details that differ between these three species and others are found in Table 2 in the Discussion. Habitat . The Powell Basin is known as a dynamic environment based on currents and sedimentation patterns. Surficial sediments collected as part of the ANDEEP III survey at a site near the type-locality of Caulleriella fimbriata n. sp. consisted of dark greyish brown, poorly sorted mud with sand (3%), silt (66%), and clay (31%) (Howe et al. 2007). Distribution . Southern Ocean, Powell Basin, 1884 m. : Published as part of Blake, James A., 2018, Bitentaculate Cirratulidae (Annelida, Polychaeta) collected chiefly during cruises of the R / V Anton Bruun, USNS Eltanin, USCG Glacier, R / V Hero, RVIB Nathaniel B. Palmer, and R / V Polarstern from the Southern Ocean, Antarctica, and off Western South America, pp. 1-130 in Zootaxa 4537 (1) on page 48, DOI: 10.11646/zootaxa.4537.1.1, http://zenodo.org/record/3771214 : {"references": ["Howe, J. A., Wilson, C. R., Shimmield, T. M., Diaz, R. J. & Carpenter, L. W. (2007) Recent deep-water sedimentation, trace metal and radioisotope geochemistry across the Southern Ocean and Northern Weddell Sea, Antarctica. Deep-Sea Research II, 54, 1652 - 16812. https: // doi. org / 10.1016 / j. dsr 2.2007.07.007"]}