Chaetozone Malmgren, 1867
Chaetozone sp. 6
Voucher specimen. SEALION: station 5MFB.
Diagnosis. Sealion 5MFB specimen is a fragment, 5.9mm long with 37 chaetigers. Body slightly dorso-ventrally flattened, anterior not widening distally; dorsal surface flat with dorsal gutters at boundary of notochaetae and dorsal surface; anterior abdominal chaetigers concertina-shaped. Pygidium not observed.
Prostomium conical with pointed tip. Peristomium longer than wide, with three broad annulations; slightly domed, obscuring the annulations dorsally. Dorsal tentacles situated on distal edge of peristomium, appearing to be displaced distally when viewed dorsally; first branchiae difficult to distinguish but situated lateral to the dorsal tentacles and just dorsal to the notochaetae of the first chaetiger, not situated on an achaetigerous segment; subsequent branchiae lie above notochaetae.
Thoracic chaetae capillaries, 4–5 chaetigers in length, up to 11 in the notopodia and 7–8 in neuropodia. Spine-like chaetae in anterior segments but acicular spines not observed in this fragment.
MGSP. No obvious staining pattern, diffuse over the anterior.
Remarks. Chaetozone sp. 6 differs from the other Falkland Islands Chaetozone species by the long peristomium with large annulations, the position of the dorsal tentacles in relation to the first branchiae and chaetiger, the body shape and the form of the acicular chaetae in the distal chaetigers.
Chaetozone sp. 6 differs from the other species recorded in the region by the way the position of the dorsal tentacles in relationship to the first branchiae and the first chaetiger. C. sp. 6 is not as inflated in the body as C. pinguis Hartman, 1978. The FI species lacks the curved acicular spines observed by Hartmann-Schröder (1965) for C. curvata. Chaetozone sp. 3 differs from C. andersenensis (Augener 1932) in the shape of the prostomium which is acutely pointed but blunt in the latter species, and the shape of the body which is dorsally flattened in the FI specimen but rounded in Augener’s species.
