低盐度海水和淡水对中华绒螯蟹性腺发育及交配行为的影响

Effects of Brackish Water and Fresh Water on Gonadal Development and Mating Behavior in Adult Chinese Mitten Crab

研究了低盐度海水(盐度为15)和淡水(盐度为0)对中华绒螯蟹(Eriocheir sinensis,以下简称河蟹)性腺发育及交配行为的影响,并比较了河蟹交配和产卵前后的性腺指数及肝胰腺指数的变化。实验分为4组,分别为低盐度海水雌蟹组、淡水雌蟹组、低盐度海水雄蟹组和淡水雄蟹组。结果表明,(1)各组河蟹的成活率均在80%左右,无显著差异(P>0.05);(2)实验第15天、30天和45天时,低盐度海水雌蟹组的卵巢指数显著高于淡水雌蟹组(P<0.05),低盐度海水雄蟹组的性腺指数也略高于淡水雄蟹组,但差异不显著(P>0.05);(3)实验第30天时,低盐度海水雌蟹组的肝胰腺指数显著低于淡水雌蟹组(P<0.05),其余采样时间两组雌体间或两组雄体间的肝胰腺指数差异不显著(P>0.05),实验期间,两组雌体的肝胰腺指数均显著下降(P<0.05);(4)实验第45天,低盐度海水雌蟹组和雄蟹组实验个体全部能够交配,有66.7%的低盐度海水雌蟹组的个体交配后2 d内产卵,淡水雄蟹组有部分个体在低盐度海水中有发情行为;(5)低盐度海水组,雌蟹产卵后和雄蟹交配后的性腺指数均显著下降(P<0.05),但肝胰腺指数下降不显著(P>0.05)。

This study was conducted to investigate the effects of brackish water （salinity=15） and fresh water （salinity=0） on gonadal development and mating behavior in adult Chinese Mitten Crab, Eriocheir sinensis. The gonadosomatic index （GSI） and hepatosomatic index （HSI） were also compared between pre-and post-mating/spawning of E.sinensis. There were four treatments in the current study, i.e. females cultured in brackish water （FB）, females cultured in fresh water （FF）, males cultured in brackish water （MB）, and males cultured in fresh water （MF）. The results showed that： （1） the survival of each treatment was around 80% and no significant difference was observed among different treatments; （2） the GSI of FB was significantly higher （P〈0.05） than that of FF; although the GSI of MB was higher than that of MF, no significant difference was observed between the two treatments; （3） for the samples collected at day 30, the HSI of FF was higher than that of FB, but no significant difference was detected between two male or female treatments for other samplings; （4） at day 45, all crabs from FB and MB had mating behaviors and 66.7% of FB females spawned during two days of post-mating. Some MF crabs had estrous behaviors; （5） for the successful mating couples of FB and MB, the GSI decreased significantly after mating/spawning. In conclusion, brackish water can enhance the gonadal development and mating for adult E.sinensis, particularly for females.