Chaetocirratulus pinguis Hartman 1978
- Dataset
- 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
- Rank
- SPECIES
- Published in
- 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. Zootaxa 4537 (1): 1-130, DOI: 10.11646/zootaxa.4537.1.1
Classification
- kingdom
- Animalia
- phylum
- Annelida
- class
- Polychaeta
- order
- Terebellida
- family
- Cirratulidae
- genus
- Chaetocirratulus
- species
- Chaetocirratulus pinguis
description
Description. A small species, specimen from USNS Eltanin Sta. 1089 (USNM 1013943) 6 mm long and 5.2 mm wide for 48 setigerous segments; types smaller, up to 4.2 mm long for 30 segments. Body distinctly fusiform in shape in types (Fig 36 A) and some non-types; juveniles more elongate, thick, tapering posteriorly, thickened in middle, but not distinctly fusiform. Individual segments biannulate (Fig. 36 B). Shallow mid-dorsal groove apparent in some specimens (Fig. 36 A). Color tan, with no additional pigmentation. Prostomium broadly rounded on anterior margin, subtriangular in shape, wider than long (Fig. 36 A – B). Peristomium well developed, dorsally overlapping first segment somewhat, with deep lateral grooves forming three weakly developed annular rings, well developed laterally (Fig. 36 B); dorsum of peristomium relatively smooth, without dorsal crest (Fig. 36 A). Dorsal tentacles medial in location, arising from groove between peristomium and setiger 1 (Fig. 36 A – B) or anterior margin of first setiger; tentacles thick, short in preservation. First pair of branchiae arising lateral to dorsal tentacles in same groove between peristomium and setiger 1 (Fig. 36 A – B); subsequent branchiae arising dorsal to setal fascicles (Fig. 36 B), continuing through first half of body. Capillary setae in noto- and neuropodia throughout; acicular spines in notopodia from middle and posterior setigers and in neuropodia from setiger 1 – 5. Acicular spines short, straight (Fig. 36 D – E); capillaries sometimes with finely serrated or fringed border (Fig. 36 E, inset). Pygidium terminating a conical lobe ventral to anal opening (Fig. 36 A). Methyl Green stain. The prostomium stains lightly; the peristomium stains heavily, especially on the sides; the body segments are generally unstained.
description
Figure 36
discussion
Remarks. Chaetocirratulus pinguis is similar to C. andersenensis in that most specimens have a robust, fusiform body. The two species differ in that the first has acicular spines present in the neuropodia from anterior setigers 1 – 5 instead of a far posterior setiger. Chaetocirratulus andersenensis has acicular spines limited to a few posterior neuropodia, rarely in notopodia; whereas in A. pinguis, acicular spines are present in both noto- and neuropodia throughout. In addition, the three peristomial rings are typically prominent and well-defined in C. andersenensis, but only weakly developed in C. pinguis, giving the pre-setigerous region a smooth appearance. Habitat. Chaetocirratulus pinguis was noticeably abundant in the vicinity of the former Larsen Ice Shelf A where the surficial sediments (0 – 5 cm) consist of 0 – 40 % sand likely derived from the formerly overlying ice cover (Gilbert & Domack 2003).
distribution
Distribution. Weddell Sea and Antarctic Peninsula in shelf and upper slope depths, 317 – 865 m; East Antarctica, 203 m.
materials_examined
Material examined. Weddell Sea, USCG Glacier Sta. 69 - 1, 24 Feb. 1969, 74 ° 28.1 ʹS, 30 ° 31.7 ʹW, 513 m, holotype (USNM 46782) and 13 paratypes (USNM 46783); Sta. 68 - 5, 9 Feb 1968, 76 ° 00 ʹS, 55 ° 00 ʹW, 400 (1, USNM 46800); Sta. 69 - 7, coll. 01 March 1969, 77 ° 16 ʹS, 42 ° 38 ʹW, 512 m, (1, USNM 490733); Weddell Sea, east of former Larsen Ice Shelf A Area, RVIB Nathaniel B. Palmer Cr. 2000 - 03, coll. J. A. Blake, Sta. 26, 23 May 2000. 64 ° 39.564 ʹS, 059 ° 13.226 ʹW, SM grab, 564 m (1, MCZ 149836). — East Antarctic Peninsula, Prince Gustav Channel, RVIB Nathaniel B. Palmer Cr. 2000 - 03, coll. J. A. Blake, SM grab, Sta. 01, 14 May 2000, 64 ° 17.625´S, 058 ° 34.678´W. 768 m (1, JAB); Sta. 34, 24 May 2000, 64 ° 10.995 ʹS, 058 ° 34.140 ʹW, 865 m (5, MCZ 149837; 1 SEM stub, JAB); N of Larsen Ice Shelf Area A, off Lindenberg Island, RVIB Nathaniel B. Palmer Cr. 2000 - 03, coll. J. A. Blake, SM grab, Sta. 03, 15 May 2000, 64 ° 53.533 ʹS, 059 ° 30.694 ʹW, 385 m (1, MCZ 149838); former Ice Shelf A Area, Greenpeace Trough, RVIB Nathaniel B. Palmer Cr. 2000 - 03, coll. J. A. Blake, SM grab, Sta. 22, 20 May 2000, 64 ° 46.632 ʹS, 060 ° 21.557 ʹW, 868 m (1, LACM-AHF Poly 10214); Sta. 12, 19 May 2000, 64 ° 55.101 ʹS, 060 ° 24.459 ʹW, 317 m (1, LACM-AHF Poly 10215); former Ice Shelf A Area, border with Larsen B, RVIB Nathaniel B. Palmer Cr. 2000 - 03, coll. J. A. Blake, SM grab, Sta. 13, 19 May 2000, 64 ° 53.517 ʹS, 060 ° 28.836 ʹW, 323 m (1, LACM-AHF Poly 10216); Sta. 14, 19 May 2000, 64 ° 51.818 ʹS, 060 ° 33.438 ʹW, 419 m (4, LACM-AHF Poly 10217). — South Shetland Islands, Clarence Island, USNS Eltanin, Cr. 12, Sta. 1089, 17 Apr 64, 60.78 ° S, 53.507 ° W, Blake trawl, 641 m (1, USNM 1013943). — Ross Sea, Pennell Bank, off Ross Ice shelf, ca. 385 km W of McMurdo Station, USNS Eltanin Cr. 32, Sta. 2060, 25 Jan 1968, 77.98 ° S, 178.18 ° E, Camera grab, 647 m (1, USNM 1490734).