Reproductive biology of the Rabbitfish (<i>Siganus canaliculatus</i>) in the Gulf of Mannar region, India

Abstract

Rabbitfish, <i>Siganus canaliculatus </i> were collected from the Mandapam area of the Gulf of Mannar region between November 2000 and October 2002. Mean sex - ratio was dominated by the females throughout the year except in September and October. Frequency distribution of mature males and females in different length groups showed that 50 % of males and females attain maturity at 132 mm and 139 mm of total length respectively. The gonadosomatic index (GSI) and condition factor (K_n) values revealed that the spawning takes place between November and March with a peak in January. Regression analysis of Fecundity (F) with total length, total body weight and ovary weight was - 872709.4 + 5940.21 TL (r = 0.9916), - 30839.4 + 3155.7 BW (r = 0.9998), - 116711.19 + 50566.9 OW (r = 0.9949) respectively.