On marine polychaeta from Mandapam (South India)

Abstract

During a stay at the Central Marine Fisheries Research Station, Mandapam Camp (S. India), in April 1958, an opportunity arose to collect some Polychaetes from the Gulf of Marmar. Special attention was paid to the small forms which hitherto have been rather neglected in Indian waters. The 17 samples taken comprise 50-55 species, most of which cannot be identified at present owing to lack of literature. Eight of them, from groups more familiar to the author, have been selected for a detailed study. Of these, Prionospio sexoculata Augener has already been recorded in this area ; but Prionospio malmgreni Claparede and Oriopsis armandi (Claparede) are new to India ; Poecilochaetus serpens (Claparede) and Raphidrilus nemasoma Monticelli are new to the Indian Ocean while Dorvillea mandapamae, Oriopsis coalescens and Augeneriella hummelincki Banse, subsp. indica are new to science. Fauvel (1953) estimated that the 450 species of Polychaetes known from India, represent hardly more than one half of the number to be expected. It may be added that comparatively few small species have been collected from the region of the Indo-West-Pacific so far; thus, it may be assumed that among the smaller forms of Polychaetes, as well as of other invertebrate groups, a vast number still remains to be discovered in this region. It may be mentioned that in the present material, of the subfamily Exogoninae of the Syllidae, alone, three species have been found (Exogone sp., Sphaerosyllis sp. and Brania sp.) though biotopes favoured by them, like the phytal proper, or coral reefs, have not been touched. This subfamily was not previously recorded from India. Among the Sabellidae also, Amphiglena mediterranea (Leydig) is new to India.