Chaetozone spinosa Moore 1903
- 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
Classification
- kingdom
- Animalia
- phylum
- Annelida
- class
- Polychaeta
- order
- Terebellida
- family
- Cirratulidae
- genus
- Chaetozone
- species
- Chaetozone spinosa
distribution
Distribution. Off Japan, 280 m; off California, ca. 2000 – 3100 m; Peru-Chile Trench, 4100 m.
materials_examined
Material examined. Off Peru, Peru-Chile Trench, SEPBOP, R / V Anton Bruun Cr. 17, Sta. 663 - C, 13 ° 44 ʹS, 77 ° 33 ʹW, Menzies trawl, 4100 m, 2 specimens (USNM 1490777). Descriptive remarks. Chaetozone spinosa is a deep-sea species previously known from off Japan and northern California (Blake 1996, 2006). The two incomplete specimens from the Peru-Chile Trench are smaller than those from off California but agree well with the descriptions presented in those two papers. A brief description follows. In this species, the body is thickest anteriorly and broadly flattened dorsally (Blake 2006: Fig. 6 E). The prostomium is short, triangular, and fused with and mostly indistinguishable from the peristomium. The prostomium and peristomium together form a large, heart-shaped head that is distinctly set off from a reduced segment 1 (Blake 2006: Fig. 6 E – F). Segment 1 lies between the peristomium and setiger 1 and is visible both dorsally and laterally (Blake 2006: Fig. 6 F); the first pair of branchiae arise on this reduced segment as apparently do the tentacles. Setiger 1 is larger than following ones, bearing a pair of branchiae located dorsal to notochaetae. Setae of anterior segments include capillaries; long natatory capillaries are present on the two specimens here. The noto- and neurosetal fascicles of capillaries nearly merge laterally, with little space between them. Neuropodial acicular spines are present from setigers 21 – 25 (per Blake 2006), but in the present smaller specimens they occur from setiger 12 – 13; notopodial acicular spines occur from setiger 29 in the larger specimen. General remarks. The two specimens, while incomplete, are well preserved and retain the form of the unusual pre-setal “ head ” that dominates the anterior end and provides ready recognition for this species. The narrow achaetous segments between the “ head ” and setigerous segments are as previously described. Chaetozone spinosa is a deep-sea species; the present specimens from the Peru-Chile Trench represent its deepest record and most southern location.
Name
- Homonyms
- Chaetozone spinosa Moore 1903