Spawning congregations of Indian squid Loligo duvauceli (Cephalopoda : Loliginidae) in the Arabian Sea off Mangalore and Malpe

Abstract

Two successive spawning congregations of Loligo duvauceli occurred along the southern Karnataka coast during 1990 and 1991. The congregations took place during the postmonsoon months (Sept.-Oct) and resulted in steep increase in catch rates of squids in trawlers and purse seiners operating from Mangalore and Malpe. Occurrence of such notable quantities of large sized mature squids during September-October of 1990 and 1991 is attributed to the increase in seawater temperatures along the inshore areas during the period. Further, new evidences like, low gonadosomatic index and tangible growth after reaching sexual maturity are presented to highlight a non-semelparous reproduction in this tropical inshore squid.