Size distribution and growth of Metapenaeus dobsoni(Miers) and their effect on the trawler catches off Kerala

Metapenaeus dobsoni (Miers) spawns almost throughout the year. The traditional method of tracing the \nprogression of modes in monthly length frequency distribution to determine growth and age was not very \nsuccessful. The application of a modified Von Bertalanffy equation furnished expected sizes at different ages. \nThe total instantaneous mortality rate was found out from the approximate formulae of Holt-Beverton. The size distribution of the catches landed by trawlers were obtained and the role played by the size distribution \nin influencing the catch and abundance has been discussed.