Selection response and reproduction performance of selected giant freshwater prawn (Macrobrachium rosenbergii)

High productivity and good performance of the harvested prawn is the main goal of the intensive culture of the giant freshwater prawn (GFP). The prawn size influences its market price, where the bigger prawn has a higher price. The purpose of this study was to evaluate the selection response and reproduction performance of two generations of selected prawn. The selection was conducted by simultaneous mass selection method, consist of traits of body standard length and maturation stage of the GFP female, on the GIMacro (Genetic Improvement of the Macrobrachium rosenbergii) strain. Selective breeding to produce faster growth and later maturation in GFP was done by selection for two generations to obtain 20 percent of the bigger size and lower maturation stage for female prawns as the broodstock candidates on the next generation. The result of this study showed that the selection response on growth trait of the GFP was moderate, with 9.68% and 7.77% for the first-generation (G1) and the second-generation (G2), respectively. The bigger selection response was obtained on the maturation trait of the female GFP, with 31.25% and 46.15% for G1 and G2, respectively. The proportion of male morphotype of the harvested prawn was relatively similar, with 46%, 40%, and 47% for G0, G1 and G2, respectively. The result suggests that the simultaneous selection on standar lenght and sexual maturation stage of the female is an effective method to improve the productivity of the GFP.