Journal of the Marine Biological Association of India

Volume 46 Issue 2

Distributional record and biological notes on two deep-sea sharks, Centrophorus acus Garman and Squalus megalops (Macleay), from Andaman waters

R. Soundararajan and S. Dam Roy
Abstract

Two deep-sea squaliform dogfishes Centrophorus acus Garman and Squalus megalops (Macleay), have been recorded from Andaman waters, the former for first time from the entire Indian Ocean and the latter from the eastern Indian Ocean. Both the species were collected from the catches of vertical hand lining off southwest coast of South Andaman Islands at depths between 200 and 400 metres during 1988 to 1992. The morphometric characters were compared with the description of Compagno (1984) for confirming the identity of the two species. C. acus was found to be a prolonged and continuous breeder and is ovo-viviparous. Only the left ovary and uterus are functional and each gravid female contained mostly one developing embryo or foetus at a time. The age, growth and length-weight relationship of C, acus was worked out. S. megalops also is ovo-viviparous and both right and left ovaries and uteri are functional. Each gravid female was found to bear 5 to 7 embryos/foeti shared in the uteri. These sharks are commercially important due to their high liver oil and squalene content. The targeted fishing of sex-segregated population of C. acus, having a very low fecundity, warrants monitoring for conservation and regulation of the fishery.

Keywords

Deep sea sharks, distribution, biology, fishery, Andamans

Date : 30-12-2004