Chaetozone Malmgren, 1867
Chaetozone sp. 3
Voucher specimen. Sealion 15 MFA, 12 MFC, 2 MFB
Diagnosis. Specimen from 15 MFA complete, 8mm in length with approximately 70 chaetigers. Body slightly flattened dorso-ventrally, widening gradually becoming widest in distal thoracic chaetigers, dorsal groove present in some specimens, mid-section inflated and segmentation poorly defined, distal abdominal chaetigers flattened dorso-ventrally and becoming concertina-shaped; pygidium with four rounded lobes, ventral lobes joined at their bases.
Prostomium sharply pointed. Peristomium short wider than long, with three annulations. Dorsal tentacle bases arising laterally on peristomium extending and emerging dorsally. First branchiae arising on an achaetigerous segment, situated lateral to where dorsal tentacles emerge dorsally; subsequent branchiae in line with first branchiae or slightly more ventral, above the notochaetae.
Chaetae in thoracic segments capillaries, short about 2 to 3 chaetigers in length. Acicular spines starting about half way down body, slightly curved with rounded or blunt tips, spines alternating with short, thin, acutely-pointed chaetae, three to five spines in a fascicule, similar arrangement in both noto- and neuropodia although notochaetae may be slightly longer; fascicules separated, not forming cinctures.
MGSP. Stain band at base of prostomium, diffuse stain on peristomium.
Remarks. Chaetozone sp. 3 can be distinguished from other FI Chaetozone species, particularly Chaetozone sp. 2, by the arrangement of the dorsal tentacle the base of which arises laterally and extends dorsally, the peristomium region is not domed, the capillary chaetae of the thoracic chaetigers are short and abdominal chaetae not forming cintures.
Chaetozone sp. 3 differs from the other species recorded in the region by the way the dorsal tentacles emerge. The FI species lacks the curved acicular spines observed by Hartmann-Schröder (1965) for C. curvatus. 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.
