Correlation of growth and survivorship for Macrobrachium rosenbergii in different culture conditions

To study the correlation of important economic traits of Macrobrachium rosenbergii in different conditions,each of 106 families of M.rosenbergii was randomly divided into two groups and cultivated for two months at different densities in two ponds of different sizes.The cephalothorax length,abdomen length,body length,body weight and survivorship for each family were measured,and correlation analysis for the growth traits and survivorship was done between the two treatments.The correlation analysis revealed positive yet not significant correlation of the growth traits(cephalothorax length,abdomen length,body length)between the two treatments,and the correlation coefficients were 0.109,0.15 and 0.143(P0.05),respectively.Significant positive correlations were found for body weight(r=0.223,P0.05)and survivorship(r=0.644,P0.01)of M.rosenbergii in the two ponds.Coefficients of variation(CV)for cephalothorax length,abdomen length and body length were between 10.85~18.09,and the CV for body weight in the two ponds were 36.80 and 43.47,indicating for a greater potential for genetic selection in body weight.The experiment suggested that,selection for M.rosenbergii may obtain different results although in the same trend,when either body weight or survivorship was chosen as the selection index in different culture conditions.