Sphaerosyllis perspicax Ehlers, 1908
Voucher. SEA LION: station 19MFC
Diagnosis. Voucher is a complete specimen; very small, slender species; 3mm long and 0.35mm wide for 28 chaetigers, pygidium damaged. Integument papillated; colour in alcohol pale yellow. Prostomium about twice as wide as long bearing three antennae and two palps. Palps fused along their length, short. Antennae smooth, arising nearly at same level, bottle-shaped, of equal size. Two pairs of large red eyes present, arranged in almost straight line, inner pair large, posterior pair smaller; pair of small red eyespots present, positioned anteriorly on prostomium. Pharyngeal tooth located near anterior margin. Proventricle short, extending through chaetigers 2-4.
First segment achaetous laterally with a pair of smooth, short, bottle-shaped tentacular cirri. Parapodia uniramous, short but distinct, conical. Dorsal cirri on chaetiger 2 absent, in other chaetigers bottle-shaped (similar to antennae and dorsal cirri) in anterior chaetigers, becoming progressively elongated and narrow in posterior chaetigers.
Chaetae observed were falcigers with slender, slightly curved, unidentate blades; chaetae often broken off, simple chaetae likely broken off. Acicula clearly observed in posterior chaetigers, where solitary, acuminate. Pygidium damaged.
Remarks. Falkland Islands specimens agree well with Sphaerosyllis perspicax Ehlers, 1908 described from South Georgia, which probably belongs to Erinaceusyllis according to San Martin (2005). Specimens agree in that anterior dorsal cirri are strongly inflated at their bases and absent form chaetiger 2, the eyes and the antennae are both arranged in line, the palps are completely fused all along their length. Females brooding eggs dorsally, by means of capillary notochaetae were observed in material from Falkland Islands.