Standardising stocking density for freshwater prawn Macrobrachium rosenbergii (De Man, 1879) farming in coconut garden channels

Abstract

The effect of stocking density on the population structure, growth characteristics and production of freshwater prawn Macrobrachium rosenbergii in coconut garden channels was studied. A randomised block design of four treatments andfour replicates was used and the only difference being the stocking densities which ranged from 5000ha-1 to 25,000ha-1. The mean weight and survival at the time of harvest varied from 55.5 g to 101.7 g and 28.21% to 69.44% respectively. At lower densities the proportion of undersized non-marketable prawns was relatively low. However, net production increased with stocking density from 90.1 (TC-1) to 199.7 kg.ha-1.8 months- 1 (TC-4). Final marketable yield structure and economics revealed that the stocking density of 15,000ha-1 was optimum for coconut garden channels in Kuttanad. Present study suggests that the profit incurred from freshwater prawnfarming is directly related with production of larger orange-clawed and blue-clawed morphotypes. Hence stocking density was found as an essential component for ensuring better marketable yield and improving the economic returns. This study provides significant information since most coconut garden channels are abandoned water areas which when utilised properly can be an additional source of income especially to agriculture farmers in India and other Asian countries. Introduction