Abstract:The present study was conducted to evaluate the differences between the growth and reproductive molting of Exopalaemon carinicauda. In this milieu, we analyzed the differences in the representative stages (intermoult C, premoult D, and postmolt AB) of the two types of molting in relation to three parameters: non-specific immune indexes including phenoloxidase (PO), superoxide dismutase (SOD), acid phosphatase (ACP), alkaline phosphatase (AKP), molting-related enzyme (Chitinase), and ecdysone concentration (MH). The activity of PO during different stages of growth molting exhibited no significant difference. While the activity of PO during reproductive molting decreased at first and then increased, and showed significant differences among different stages. At the intermoult stage, the activity of PO of growth and reproductive molting was not significantly different. At the premoult stage, the activity of PO of reproductive molting was significantly lower than that of growth molting. At the postmoult stage, the activity of PO of reproductive molting was significantly higher than that of growth molting. During growth molting, the activity of SOD at all the three stages gradually increased, and demonstrated significant differences. During reproductive molting, the activity of SOD at the postmoult stage was significantly lower than that at the other two stages, and the difference between the intermoult and premoult stages was not significant. At the intermoult stage, the activity of SOD of reproductive molting was significantly higher than that of growth molting. At the premoult stage, there was no significant difference between them, while at the postmoult stage, the SOD activity of reproductive molting was significantly lower than that of growth molting. During growth molting, the activity of AKP and ACP at all the three stages had the same trend, that is they increased at first and then decreased, and the difference was significant. The activity of enzymes during reproductive molting had the same trend as those during growth molting. However, the activity of enzymes at all the three stages during growth molting was significantly higher than that during reproductive molting. At different stages of growth molting, chitinase activity and MH hormone concentration had the same trend, that is they gradually increased, and the difference of the stages was significant. Furthermore, during reproductive molting, they decreased at first and then increased, and the differences between the stages were significant. During the intermoult and premoult stages, chitinase activity and MH hormone concentration of growth molting was significantly lower than those of reproductive molting. During the postmoult stage, chitinase activity and MH hormone concentration of growth molting were significantly lower than those of reproductive molting. The present study conducted is a preliminary study on growth and reproductive molting. The results showed that there was a significant difference between the growth and reproductive molting because of the ovary development. The results provide a theoretical base and a scientific ground for further research on the mechanism of molting and artificial breeding.
