基于鳗鱼道诱鱼技术研究花鳗鲡幼鱼光色趋向性

Phototaxis of Anguilla marmorata based on fish attracting technology of eel passage

为保护我国花鳗鲡资源,提高鳗鱼道入口吸引力,本研究以3 W水下景观灯为光源,利用自制多功能圆池设计了3种试验工况,探索花鳗鲡幼鱼的光色趋向性.结果表明:3种试验工况下,鱼类在光区与暗区单位面积出现比例分别为(8.7±0.3)%和(3.6±1.7)%、(8.4±0.2)%和(5.0±1.4)%、(9.0±0.2)%和(1.9±1.3)%,且分布在光区的幼鱼多处于玻璃鳗发育阶段,而暗区的幼鱼多处于线鳗阶段(或向线鳗发育).光色区中鱼类出现次数百分比排在前3的分别为黄光区[(29.4±4.9)%]、红光区[(24.1±3.9)%]和紫光区[(17.2±4.0)%];黄光区[(29.4±3.3)%]、紫光区[(25.2±3.7)%]和红光区[(18.2±2.9)%];红光区[(33.3±2.3)%]、紫光区[(25.6±3.8)%]和黄光区[(20.7±5.7)%].首先进入光区次数排在前3的分别为红、黄、紫光区;红、紫、黄光区;红、紫、黄光区.鱼类在上述3种光区中的总进出次数处于蓝绿光和五彩光之间,且红光和黄光下鱼类会出现视觉疲劳.花鳗鲡幼鱼对光的趋向性由其发育阶段决定,玻璃鳗对光色具有趋向性,尤喜爱红、黄和紫光,在鳗鱼道入口采用灯光诱鱼可帮助玻璃鳗找到生长洄游通道.

Light trap is commonly used in protecting Anguilla marmorata resource and improving the attraction of eel passage entrance.In this study,a self-made multifunctional round pool was used to explore the phototaxis of elvers(A.marmorata)under three conditions.3 W underwater landscape lamp was used as the light source.The results showed that the percentages of juvenile A.marmorata occurrence in light zone and dark zone were(8.7±0.3)%and(3.6±1.7)%,(8.4±0.2)%and(5.0±1.4)%,(9.0±0.2)%and(1.9±1.3)%respectively under three conditions.Moreover,most glass eel distributed in the light zone,while elver(or elver develop)distributed in the dark zone.The primary regions of fish occurrence and its percentages were yellow zone[(29.4±4.9)%],red zone[(24.1±3.9)%)]and purple zone[(17.2±4.0)%]for condition one,yellow zone[(29.4±3.3)%],purple zone[(25.2±3.7)%]and red zone[(18.2±2.9)%]for condition two,and red zone[(33.3±2.3)%],purple zone[(25.6±3.8)%]and yellow zone[(20.7±5.7)%]for condition three.Correspondingly,the top three regions of fish first entering were red,yellow and purple,red,purple and yellow,and red,purple and yellow,respectively.The number of entering and exiting for fish in those three color zones was between blue-green zone and colorful zone.Visual fatigue would occur for elvers with continuous exposure to red light or yellow light.Our results suggested that the phototaxis of elvers is dependent on their developmental stages.Glass eels have phototaxis and seem to be more interesting in red,yellow,and purple light.Light guidance fish is available in the entrance of eel passage,which can help glass eels find the migration channels.