Studies on some aspects of reproductive biology of Shovelnose catfish, Arius subrostratus (Valenciennes, 1840) from Cochin estuary, India

Abstract

This study describes some aspects of reproductive biology and breeding cycle of an estuarine catfish Arius subrostratus from Cochin estuary, India. For this study monthly sampling was conducted from Cochin estuary (76o 9’25” E - 76o 24’28” E and 9o 47’31” N - 10 o 12’N) during April 2011 to March 2013 period. The minimum size at first maturity of A. subrostratus during the study period was 235 mm. The higher Gonadosomatic index occurred during October to January was an indication of spawning season of the species. Fecundity varied from 11 to 34 eggs during the period and ova diameters were ranged from 0.022 mm to 14.5 mm. The sex ratio calculated was 1: 1.1. From the ANOVA result GSI was significant at 5 % level between different months. This study revealed that A. subrostratus from Cochin estuary showed breeding season during Northeast monsoon period.