A comparison of gender growth performance of Procambarus clarkii (Girard, 1852) under aquaculture conditions

Abstract

The red swamp crayfish, Procambarus clarkii (Girard, 1852) is one of the most commonly-farmed freshwater species in inland China, but the yield is very low. The aim of this study was to assess whether the gender has effect on growth performance of P. clarkii. Male and female juvenile crayfish were individually reared in net cages for 75 days (trial 1). In addition, juvenile crayfish and adult crayfish of different gender were group-reared for 60 days and 30 days respectively (trials 2 and 3). The weight growth rate (WGR, %), length growth rate (LGR, %) and survival rate (SR, %) were monitored. Results showed that the length-weight regressions differed significant between males and females juvenile crayfish (P < 0.05). Furthermore, the significant differences were noted at 60 and 75 days (P < 0.05), when body length was used as a covariate. It indicated that secondary sexual characteristics emerged when the body length reached 5.0-5.5 cm. The SR, LGR and WGR were not significantly different among juvenile crayfish gender groups, but adult male or female crayfish in mixed-sex rearing grew significantly faster than those kept in monosex rearing. A significant difference in terms of WGR (P < 0.01) (mixed-sex > females > males) was noted among monosex and mixed-sex groups. No significant difference was noted, in terms of LGR, between females and males (P > 0.05). However, the LGR of each of these was significantly lower than that of the mixed-sex groups (P <0.01). Our results demonstrated the gender has some effect on growth performance of P. clarkii, especially on adult crayfish.