Maturity, spawning and feeding intensity of cobia Rachycentron canadum (Linnaeus, 1766) in northwest coast of India

An attempt was made to provide some vital aspects of reproductive biology of cobia Rachycentron canadum (Linnaeus, 1766). Samples for a period of two years from an exploratory vessel and from the landing centers of Mumbai were used for the study. The average sex ratio between males and females observed was 1:0.80. Dominance of the number of females above the size of 100 cm was noticed. The size at first maturity of males and females was 72 and 83 cm, respectively. Similarly, age at first maturity of males and female was estimated at 1.77 and 2.17 years, respectively. Spawning season was based the on occurrence of five maturity stages and Gonadosomatic index (GSI) values indicated a throughout the year spawning behavior with peak spawning activity during July-August and November-January. Percentages of feeding condition of various maturity stages indicated that cobia take very less food during their spawning period.