Effects of high temperature on reproductive characteristics and hormones of female Eriocheir sinensis during reproduction (Brachyura, Varunidae)

Abstract Under the influence of global warming, excessive temperatures may affect adult female Eriocheir sinensis at a sensitive stage, changing the reproductive process, which is critical for the persistence of populations. Thus, the effects of high temperature on the reproductive performances and hormone changes of female E. sinensis were analysed. The results showed that the mating and spawning rates were maintained at >80% at 10–25°C and at 10–15°C, respectively. However, the spawning rate was only 16.67 ± 40.82% at 25°C. It is inferred that the spawning behaviour is more affected by high temperature, and 25°C had an adverse effect on the spawning rate. The reproductive performances (egg production, fecundity and reproductive index) of female crabs at 15°C were better than in other temperature groups. Meanwhile, the levels of DHP (17 α ,20 β -dihydroxy-4-pregnene-3-one) and E 2 (estradiol-17 β ) decreased at 25°C after spawning, indicating that 25°C might restrain the synthesis of sex hormone, which may lead to a inferior spawning rate. The results can provide a reference for the reproductive performances of female E. sinensis under high temperatures, which is conducive to the protection of E. sinensis under global warming.