不同发育阶段中华绒螯蟹摄食行为及其对饵料的选择性

Feeding behavior and feeding selectivity on the different feeds of the Chinese mitten crab(Eriocheir sinensis)at different development stages

通过养殖实验和摄食过程摄像技术,首先研究了中华绒螯蟹幼蟹、早期成蟹,亚成体和成体的摄食行为差异,评价了不同发育阶段和不同性别中华绒螯蟹的摄食行为、摄食响应时间和摄食率差异,然后进一步比较了不同发育阶段中华绒螯蟹对冰鲜鱼、配合饲料、玉米和螺蛳的摄食选择性。结果表明:中华绒螯蟹的摄食行为可分为探索、定位、试探和摄食这4个阶段,其中探索和摄食耗时较长;就探索阶段的耗时和摄食响应时间而言,幼蟹和早期成蟹的雌体显著短于雄体,而亚成体和成体阶段雄体显著短于雌体;就摄食而言,各发育阶段雌体的摄食耗时均高于雄体;就摄食率而言,中华绒螯蟹摄食率随着发育阶段的增加呈现显著下降趋势,而雌雄蟹间无显著差异;就不同饵料的摄食选择性结果而言,不同发育阶段的中华绒螯蟹对不同饵料的首次摄食频率从高到低顺序均是冰鲜鱼>配合饲料>玉米>螺蛳;雌、雄成蟹对冰鲜鱼和配合饲料的摄食响应时间均无显著差异,但均显著低于对玉米和螺蛳的。综上,不同发育阶段和不同性别中华绒螯蟹的摄食行为存在显著差异,亚成体阶段是雌、雄中华绒螯蟹摄食行为发生转变的重要发育阶段,成蟹优先摄食冰鲜鱼与配合饲料。

In this study,the differences in feeding behavior of juvenile crab,early stage of adult,sub-adult and adult Chinese mitten crabs(hereafter referred to as“river crabs”)were firstly investigated by culture experiments and camera techniques.The feeding behavior,feeding response time,and feeding rate of Chinese mitten crabs with different genders at different developmental stages were then evaluated.The feeding selectivity of river crabs at different stages of development on trash fish,formula feed,corn,and snails was further compared.The results showed that:(1)The feeding behavior of Chinese mitten crabs included four stages:exploration,orientation,testing and feeding.Among them,exploration and feeding took a long time.(2)In terms of time consumed during exploration stages and feeding response,females consumed significantly more time than males in the juvenile crab and early stage of adult stage,while males consumed significantly than females in the sub-adult and adult stage.(3)In terms of feeding,females consumed more time than males at all developmental stages.(4)In terms of the feeding rate,the feeding rate of Chinese mitten crabs tended to decrease significantly with increasing developmental stages,but there was no significant difference between females and males.(5)In terms of the selective results of feeding on different feeds,the frequency of first feed of different feeds by Chinese mitten crabs at different stages of development was ranked from highest to lowest as follows:trash fish>formula feed>corn>snail.(6)There was no significant difference in the feeding response times of male and female crabs to trash fish and formula feed,but both were significantly lower than those to corn and snail.In summary,the feeding behaviors of Chinese mitten crabs were significantly different between developmental stages and genders,and the subadult stage was an important developmental stage in which the feeding behavior of female and male crabs changed.Additionality,Adult crabs preferred to feed on trash fish and formula feed.