Chaetozone bransfieldensis ( Hartmann-Schröder & Rosenfeldt, 1989 ) Blake, 2018

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), pp. 1-130 : 77-80

publication ID

https://doi.org/ 10.11646/zootaxa.4537.1.1

publication LSID

lsid:zoobank.org:pub:169CBE5C-3A6E-438B-8A81-0491CBFBAC85

DOI

https://doi.org/10.5281/zenodo.3798554

persistent identifier

https://treatment.plazi.org/id/03A2CB16-FFB9-A205-FF36-FA16FB6EF81C

treatment provided by

Plazi

scientific name

Chaetozone bransfieldensis ( Hartmann-Schröder & Rosenfeldt, 1989 )
status

comb. nov.

Chaetozone bransfieldensis ( Hartmann-Schröder & Rosenfeldt, 1989) View in CoL new combination

Figure 42 View FIGURE 42

Tharyx View in CoL spp. Hartman 1967: 118 (in part).

Chaetozone setosa: Hartman 1978:166 View in CoL (in part). Not Malmgren, 1866.

Caulleriella bransfieldensis Hartmann-Schröder & Rosenfeldt, 1989: 67 View in CoL , figs. 3–5.

Material Examined. Antarctic Peninsula, Bransfield Strait, R / V Polarstern, Cr. ANT-III/2, Sta. 207, coll. 3 Dec. 1984, 62°59ʹS, 57°05ʹW, 68 m, holotype ( ZMH P-19615) GoogleMaps ; USNS GoogleMaps Eltanin Cr. 6, Sta. 436, 8 Jan 1963, 63.23°S, 58° W, Otter trawl, 73 m (1, USNM 1129132 About USNM ).— South Shetland Islands, south of Low Island GoogleMaps , R / V Hero Sta. 691- 26, 10 Feb 1969, 63.425°S, 62.250°W, 119–124 m, (1, USNM 187652 About USNM ); NE of Clarence Island GoogleMaps , USNS Eltanin Cr. 12, Sta. 1089, 17 Apr 1964, 60.78°S, 53.507°W, 641 m (1, USNM 56078 About USNM ); Deception Island GoogleMaps , R / V Hero, Sta. 721- 797, 12 Jan 1972, 62.972°S, 60.83°W, Petersen grab, 81 m (1, USNM 1490769 About USNM ).— Ross Sea, off Cape Adare GoogleMaps , USNS Eltanin Cr. 27, Sta. 1869, 13 Jan 1967, 71.267°S, 171.667°E, trawl, 1565–1674 m, (1, USNM 1490768 About USNM ).— Weddell Sea, Coats Land, off Halley Bay GoogleMaps , USCG Glacier, Sta. 69-1, 24 Feb 1969, 74.468°S, 30.528°W, Anchor dredge, 513 m (3, USNM 46788 About USNM ) GoogleMaps .

Description. A small to moderate-sized species, holotype approximately 10 mm long, 1.0 mm wide for 82 setigers; paratypes reported larger, 22 mm long, 1 mm wide with up to 122 setigers ( Hartmann-Schröder & Rosenfeldt 1989). Body enlarged, somewhat fusiform anteriorly, then narrowing posteriorly. Color in alcohol: light tan, with some faint dusky pigment on anterior end especially in grooves of peristomial annuli.

Prostomium triangular, narrowing to rounded tip ( Fig. 42A View FIGURE 42 ); a single pair of reddish eyespots present ( Fig. 42A View FIGURE 42 inset), or absent; each eyespot when present round with distinct lens surrounded by red pigment cup; nuchal organs not observed. Peristomium wide, with two annuli, second trapezoidal in shape, narrowing posteriorly and terminating in middle of setiger 1. Dorsal tentacles arising from setiger 1, lateral to end of peristomium ( Fig. 42A View FIGURE 42 ); first pair of branchiae lateral and posterior to dorsal tentacles on setiger 1; second pair of branchiae on setiger 2; subsequent branchiae dorsal to notosetae on each segment; most branchiae short or limited to stubs ( Fig. 42C View FIGURE 42 ).

Parapodia reduced to simple setal tori; postsetal lamellae absent. Setal fascicles of noto- and neuropodia close to one another throughout body. Notosetae long capillaries anteriorly, partially replaced by a pair of heavy curved spines from about setiger 22–24; capillary neurosetae mostly replaced by 1–2 heavy spines from setiger 9–12, spines increasing to 4–5 in far posterior setigers; noto- and neuroacicular spines in pairs throughout middle setigers ( Fig. 42B View FIGURE 42 ); posterior spines forming partial cinctures with 4–5 opposing spines arising from thin membranous elevated podial lobes ( Fig. 42C View FIGURE 42 ); 8–10 spines on a side. Spines heavy, with those most medial and newest thicker and more curved ( Fig. 42D View FIGURE 42 ). Some specimens epitokous with long, natatory setae. Pygidium a rounded disk ventral to anal opening.

Methyl Green stain. Body staining uniformly; no distinct pattern or speckling apparent.

Remarks. Caulleriella bransfieldensis is here transferred to Chaetozone because it has simple blunt-tipped spines in the noto- and neuropodia instead of bidentate hooks. The spines form partial cinctures in posterior segments as in several related species ( Blake 1996, 2015). Furthermore, the setal fascicles of noto- and neuropodia are set close together instead of widely separated as in species of Caulleriella (see Blake 1996; this study). The species is readily distinguished from Antarctic congeners by the presence of a single pair of eyespots (when present) and the heavy noto- and neuropodial spines that form partial cinctures in posterior segments.

On a global basis C. bransfieldensis is similar to C. acuta Banse & Hobson, 1968 from the Puget Sound, Washington (see Blake 1996). Both species have a pair of eyespots and acicular spines first present from anterior setigers; posterior spines are developed into partial cinctures. In C. acuta , some anterior notopodial spines are of an unusual oblique shape with fibrils present along one edge; such setae are absent in C. bransfieldensis . In C. acuta the dorsal tentacles and first pair of branchiae arise from the posterior part of the peristomium; in C. bransfieldensis , they first appear on setiger 1.

Distribution. Antarctic Peninsula, Ross Sea, Weddell Sea, shelf and slope depths, 73–1674 m.

R

Departamento de Geologia, Universidad de Chile

V

Royal British Columbia Museum - Herbarium

ZMH

Zoologisches Museum Hamburg

USCG

Universidad de San Carlos de Guatemala

Kingdom

Animalia

Phylum

Annelida

Class

Polychaeta

Order

Terebellida

Family

Cirratulidae

Genus

Chaetozone

Loc

Chaetozone bransfieldensis ( Hartmann-Schröder & Rosenfeldt, 1989 )

Blake, James A. 2018
2018
Loc

Caulleriella bransfieldensis Hartmann-Schröder & Rosenfeldt, 1989: 67

Hartmann-Schroder, G. & Rosenfeldt, P. 1989: 67
1989
Loc

Tharyx

Hartman, O. 1967: 118
1967
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