光色对中华绒螯蟹幼体诱集与仔蟹摄食的影响

为揭示不同发育阶段中华绒螯蟹Eriocheir sinensis对光照颜色的行为反应,探究蟹类颜色视觉的特征,采用自制的试验装置,研究了蓝光(波长446~493 nm)、绿光(波长502~579 nm)、黄光(波长586~600 nm)、红光(波长620~644 nm)、白光(波长440~637 nm)对中华绒螯蟹Ⅱ~Ⅴ期溞状幼体与大眼幼体的诱集效果,以及对仔蟹摄食的影响。结果表明:在室内试验装置中,Ⅱ~Ⅴ期溞状幼体和大眼幼体在蓝光下的分布率最高,极显著高于其他光照组(P0.01),各期幼体在绿光下的分布率也不同程度地高于其他光照组;在室外土池中,采用容积为1 L的捕苗器,在蓝光下捕获大眼幼体的数量最多,为1097尾,极显著高于白光组(253尾)、红光组(121尾)和黄光组(35尾)(P0.01),显著高于绿光组(629尾)(P0.05);24 h内各光色组中仔蟹的昼夜摄食量结果显示,各组仔蟹的日摄食量无显著性差异(P0.05),白天摄食量平均值高于夜晚,但差异并不显著(P0.05)。

Effects of color light on aggregation of larvae and food intake in juvenile Chinese mitten hand crab Eriocheir sinensis

Chinese mitten hand crab Eriocheir sinensis larvae and juveniles were reared in a tank made by authors under various light colors including blue ( 446-493 nm ) , green ( 502-579 nm ) , yellow ( 586-600 nm ) , red (620-644 nm) and white (440-637 nm) at water temperature of 17. 3-19. 1℃ to investigate effects of color light on aggregation of the larvae and food intake of the juveniles. The results showed that the larvae from zoeaIIto zoea Ⅴ and megalopa had very significantly higher aggregation under blue light than under the other color light ( P<0. 01). The maximal megalopa (1097 individuals) in number were captured by a 1 L collector under blue light in an outdoor earthen pond, significantly higher than those under the green light (629 individuals) (P<0. 05), and very significantly higher than under white light (253 individuals) , red light (121 individuals) and yellow light (35 individuals) (P<0. 01). Observation of feeding activity revealed that there was no significant difference in food in-take in the crab juveniles among all color light groups(P>0. 05), even though higher in day time than in night time (P>0. 05).