中华鰟鮍逃逸运动的方向偏好

The Locomotive Lateralization and Its Stability of Rhodeus sinensis Günther

为考查中华鰟鮍(Rhodeus sinensis Günther)逃逸运动过程中的行为不对称性,将67尾实验鱼单独饲养,然后分别于(20±1.0)℃条件下进行10次T形迷宫实验,以确定实验鱼是否存在方向偏好(朝迷宫同一方向8次及以上则认为该实验鱼有方向偏好行为),并计算具方向偏好个体占全部实验鱼的比例;随后将上述实验在3 d后进行一次重复,以考查初次测试中具偏好个体在重复实验中是否仍保持初始方向偏好,并计算保持了初始方向偏好个体占全部实验鱼的比例。结果显示,两次测试中具方向偏好个体分别占全部实验鱼的25.4%和22.4%,其中左、右偏好分别各占9.0%、16.4%和11.9%、10.4%,两次测试之间的相对偏侧指数(Relative lateralization index,LR)没有差异(p>0.05)且均呈正态分布;经一次跟踪重复测试后,保持了初始方向偏好的个体占全部实验鱼的比例由25.4%显著下降至9.0%(p<0.05)。研究结果表明,实验鱼种群中存在具运动方向偏好的个体;评估该种鱼逃逸运动方向偏好需要进行跟踪重复测试;具稳定方向偏好的中华鰟鮍比例低于相关文献报道的其他鱼类,因此该种鱼的运动方向偏好可能对它的生存适合度的贡献较小。

To investigate whether the locomotive lateralization exhibited in Rhodeus sinensis Gtinther （evaluated by if the individual fish run to the same direction more than 8 times out of 10 T-detour trails）, we selected 67 Rhodeus sinensis Gtinther and reared indi- vidually at （20：±1.0） ℃, then we performed 10 detour trails for each individual and scoring of the direction. To investigate the re- peatability of locomotive lateralization, we repeated T-detour trails once 3 days later. In the first trail 25.4% individuals exhibited lateralization with either left 9.0 % or right 16.4 % preferences in the second trail, 22.4% individuals exhibited lateralization with either left 11.9 % or right 10.4 % preference. Furthermore, there was no significant difference in relative lateralization index （LR） between two series and the LR in both series showed normal distribution. However, after marked repeating, the proportion of individ- uals keeping initial direction significantly decreased from 25.4% in the first series to 9.0% in the second series （p〈0.05）. It suggested that locomotive lateralization exhibited in certain individuals of Rhodeus sinensis Gtinther. However, the individuals exhibited stabilized lateralization were much less than other fish species, suggesting that locomotive lateralization may have little contribution to the survival fitness of Rhodeus sinensis Gtinther. Furthermore, the results suggested that marked repeating test was important for assessing the locomotive lateralization.