Journal of the Marine Biological Association of India

Age and growth of three estuarine portunid crabs Scylla serrata, S. serrata serrata and Thalamita crenata.

Volume 29 Issue 1&2

Mercy Thomas, S. Ajmalkhan, K. Sriraman and R. Damodaran

Abstract

In Scylla serrata serrata modes were traced for a period of two years and the growth was found to be 90 and 125 mm for I and II years respectively. In Thalamita crenata modes could be traced only for an year and the growth was found to be 36 mm. Growth determined by months mode curve indicated that S. serrata can grow upto 112, 151.5 and 187.5 mm, S. serrata serrata upto 88.5, 110.0 and 130.0 mm. and T. crenata upto 34, 51 and 64 mm in the I, II and III year respectively. Growth assessed by probability plot for S. serrata was found to be upto 81.5,117,157 and 182 mm, for S. serrata serrata 71,95,5,112 and 126 mm and for T. crenata 24, 35.2, 52 and 62.2 mm in the 0,1, II and III year respectively. Employing von Bertalanfly's growth equation it was found that S. serrata can grow upto 118,162 and 180 mm, S. serrata serrata to 96,114 and 126 mm and T. crenata to 35.3, 52.2 and 62.6 mm respectively in the I, II and III year of life. The empirical length at different ages found by von Bertalanffy's growth equation showed general agreement with growth estimated by other methods. This shows that in the length ranges studied, the theoretical growth equation can be taken as adequate to indicate actual growth. The asymptotic length 0-oc) calculated by Ford-Walford method is 360, 160 and 78 mm respectively for S. serrata, S. serrata serrata and T. crenata.

Date : 31-12-1987