wo inbred groups, SS (S♀×S♂) and TT (T♀×T♂), and two hybrid groups, ST (S♀×T♂) and TS (T♀×S♂) were established. We measured the following traits in the offspring of each group: body length, body weight, carapace length, carapace width, and carapace height. The order of growth performance was ST>TS>TT>SS based on the five traits. Prior studies of gene diversity have documented strong differentiation between populations from the western Pacific Ocean and the south China Sea, providing a theoretical basis for heterosis between the Sanya and Thailand populations. Heterosis of the hybrid combination for the five traits ranged from 2.13% to 19.7% and was highest for body weight. The heterosis of the hybrid group ST was higher than that of the hybrid group TS for all traits (<0.05). There was a significant difference in body length, body weight, carapace length, and carapace height of the offspring among the four groups (>0.05). Multiple covariance analysis suggested that length, body weight, and carapace length were significantly different between the hybrid group ST and both inbred groups (<0.05). Our results provide an important reference for hybrid breeding of .