Effects and Interactions of Monosex Culture and Chelipe Removal on Growth Performance of Giant Freshwater Prawn Macrobrachium rosenbergii (De Man 1879), Raised in Cages

Abstract

This study was conducted to determine the effects of monosex culture and chelipe­-removal in cage culture of giant freshwater prawn Macrobrachium rosenbergii. Juvenile prawns (5.0g) were stocked in experimental cages in a 0.09 ha pond. Six treatments with four replicates each were (1) chelipe-removed males, (2) normal males, (3) chelipe-removed females, (4) normal females, (5) chelipe-removed mixed (1:1 ratio) males and females and, (6) normal mixed (1:1 ratio) prawns. Each cage was stocked with 30 prawns m^-2. Significantly highest growth (P<0.05) was achieved by the monosex culture of chelipe­-removed male prawns, with a mean size of 26.80 ± 0.56 g at harvest, followed by normal males, chelipe-removed mixed prawns, chelipe-removed females, normal females, and normal mixed prawns, with a mean weight of 25.10 ± 0.02, 22.30 ± 0.18, 20.75 ± 0.13, 20.20 ± 0.04 and 20.05 ± 0.08 g, respectively. Consequently, daily growth and specific growth rates were also significantly greater for the monosex culture of chelipe-removed male prawns. Better final survivals were demonstrated by the chelipe-removed groups and FCR was also significantly improved. There were significant interactions (P<0.05) between sex and removal of chelipes on major growth performance, feed utilization and protein efficiency ratio (PER) in both male and female prawns.