Age, growth and mortality studies of Indian squid, Uroteuthis (Photololigo) duvauceli (d' Orbigny) along Ratnagiri Coast of Maharashtra, India

The study on the growth and mortality of Indian squid Uroteuthis duvauceli was carried out based on the length frequency data collected during February 2012 to January 2013. Using ELEFAN, the asymptotic length ((L-infinity)) and growth coefficient (K) were estimated as 376 mm and 0.95 yr(-1) respectively. Using the von Bertalanffy's Growth Formula (VBGF), it is seen that L. duvauceli attain 233, 324 and 355 mm at the end of Ist - IIIrd years respectively. The total, natural and fishing mortalities were 4.5, 1.82 and 2.68 yr(-1) respectively. The Lc(50) was found to be 107 mm. The exploitation rate (U) and exploitation ratio (E) was calculated 0.53 and 0.54 respectively. The value of E (max) in the present study is lower than exploitation ratio E of 0.54. This indicates that to maximize the yield per recruit from L. duvauceli the efforts may be reduced from the present E of 0.54 to 0.5 to sustain the stock.