Chaetocirratulus cf. epitocus (Monro,1930)
Chaetocirratulus Blake 2018
Chaetocirratulus cf. epitoka (Monro, 1930)
Voucher specimens. VINSON WEST: stations 38MFA, 1MFA and 1MFB.
Diagnosis. Specimen incomplete, 9mm with 23 chaetigers. Body cylindrical, slightly inflated at junction between thoracic and abdominal regions, no gutters/furrows observed, dorsal surface slightly raised. Pygidium not observed.
Prostomium blunt, wide and short. In some specimens nuchal organs observed. Peristomium slightly longer than wide with three similar sized annulations. Dorsal tentacles situated dorsally arising on the edge of the peristomium. First branchiae not on an achaetigerous segment but arising on chaetiger 1. Subsequent branchiae align with first branchiae.
Chaetae in first chaetigers short about 1 to 2 chaetigers in length, subsequent chaetigers with a mix of long and short chaetae, 6-7 capillaries in each fascicule. Long chaetae also found on abdominal chaetigers but in lower numbers than thoracic chaetigers. No modified chaetae observed.
MGSP. Prostomium and peristomium deeply stain, except the nuchal organs and ventrally around the mouth, distinct lateral bands in proximal chaetigers, gradually fading in distal chaetigers; ventrally the bands extend across the body but with a distinct clear y-shaped region running down from each side of the mouth and joining in the mid-line.
Remarks. The specimens from the current study agree in basic shape with the type of Chaetocirratulus epitocus (Monro, 1930). However, Monro’s specimen is very obviously an epitoke as it is full of eggs whereas the FI specimens are not. In both the FI specimens and the holotype no modified chaetae were observed which calls into question the generic designation of the species.
The body-shape of this species, the staining pattern and the chaetal signature distinguish this species from the other FI cirratulids.