Euphrosinopsis cf. crassiseta Kudenov, 1993
Voucher specimen. NIMROD : station N8FB and VINSON WEST: 2MFA.
Diagnosis. Body short, flattened, oval and coiled up; 2.2mm long and 1.8mm wide for 13 chaetigers. Prostomium with 5 antennae, four paired antennae on anterior of prostomium, short and digitform, median antenna slightly larger than others, in two sections, with short stout basal section and a longer slender terminal. Caruncle extending to chaetiger 4. A pair of relatively large eyes present, situated between chaetigers 1 and 2.
Parapodia biramous with dorsal, lateral and ventral cirri. Branchiae present from chaetiger 1, cirriform, one per segment throughout arising just behind and laterally to dorsal cirri; dorsally cirri longer and more slender than accompanying branchiae. Other parapodial appeandaes include lateral cirrus and ventral cirrus. Chaetae very well developed, long and numerous; notochaetae of one type, forked with smooth long prongs; neurochaetae all bifurcate with coarsely serrated long prongs; ringent chaetae absent.
Remarks. This small species is consistent with Euphrosinopsis crassiseta Kudenov (1993) in having single cirriform branchia arising just behind and laterally to dorsal cirri and lacking ringent chaetae.
However previous records of this species are from much greater depth - 3697m in Weddell Sea rather than ~1000m as in Falkland Islands specimens, which we refer to Euphrosinopsis cf. crassiseta. Kudenov (1993) provided a full description of this species as well as descriptions of other euhprosinid and amphinomid species known from the area and we recommend this publication for further details. Other species collected from Falkland Islands – E. antipoda, can be distinguished by presence of ringent notochaetae.
References
Kudenov, J.D., 1993. Amphinomidae and Euphrosinidae (Annelida: Polychaeta) principally from Antarctica, the Southern Ocean, and subantarctic regions. Biology of the Antarctic Seas XXII, pp.93-150.
