Age, growth and mortality of karut croaker Johnius carutta, Bloch, 1794 off Visakhapatnam, south-east coast of India

Abstract

Age, growth and mortality parameters of karut croaker Johnius carutta were studied using the length data of 3,406 specimens ranging in length from 11 to 24.5 cm, collected from Visakhapatnam coast during January 2008 to December 2009. The von Bertalanffy growth parameters estimated were L∞ = 26.7 cm, annual K= 0.67 y-1, to= -0.1366 and T max (longevity) = 4.3 years. Length attained by the end of the first, second, third and fourth years were estimated as 14.2, 20.3, 23.4 and 25.0 cm respectively. Natural mortality (M) was estimated as 1.10, Total mortality (Z) 2.24 and fishing mortality (F) as 1.14. Exploitation rate (E) was 0.51. The growth performance index (Φ) for J. carutta (sexes pooled) was estimated as 2.679. The fishery was largely (91%) supported by first and second year age groups which are within the length groups from 13.5 to 18.9 cm.