Pseudoscalibregma Ashworth, 1901
Pseudoscalibregma bransfieldium (Hartman, 1967)
Voucher specimen. SEA LION: station 10MFB and 22MFA.
Diagnosis. A medium-sized species, body elongate, arenicoliform, expanded in anterior half then tapering to narrow abdominal region; both voucher specimens incomplete, the larger voucher 14mm long and 2.8mm wide at its widest for 25 chaetigers. Colour in alcohol light yellow. Body segments biannulate; chaetiger 1-3 not reticulated, in subsequent segments reticulationlation formed of squared cells; body surface rugose, the annulation pronounced. Pygidium missing.
Prostomium with well-developed narrow, elongated processes or horns, pointed anterolaterally; posterior margin of prostomium visible dorsally; with distinct nuchal crest on posterior half of prostomium; eyes absent. Branchiae absent.
Parapodia biramous, inconspicuous in anterior chaetigers, becoming large and well developed in middle and posterior chaetigers. Dorsal and ventral cirri present in mid and posterior chaetigers; large and inflated. All chaetigers with noto- and neuropodial fascicles of slender capillaries; in anterior region arranged into in about 5 rows, with chaetae of posterior row longest. Lyrate chaetae with unequal tynes. Pygidium unknown.
Remarks. The presence of nuchal crest on posterior part of prostomium as well as arrangement and type chaetae and form of dorsal and ventral cirri agree well with Pseudoscalibregma bransfieldium (Hartman, 1967). The reticulation has not been described by Hartman (1967) or in re-description by Blake (1981), but images provided by both authors suggest that the anteriormost segments lack distinct reticulation although these are distinctly bi-annulated as in Falkland Islands’ specimens. For comparison with other Pseudoscalibregma species collected form Falkland Islands, see entry under Pseudoscalibregma sp. 1.
Distribution: Antarctic Penisnsula, Bransfield Strait, Weddell Sea, Ross Sea and Falkland Islands. Depth distribution 335 – 916m. In Falkland Islands recorded from depths of around 500m.
