鲢幼鱼游泳能力及游泳行为的试验研究

Swimming Ability and Behavior of Different Sized Silver Carp

为了探究四大家鱼的游泳能力,指导鱼道水力学设计,提高鱼道过鱼成功率,增殖鱼类资源总量,以四大家鱼之一的鲢（Hypophthalmichthys molitrix）为试验对象,研究其游泳能力及游泳行为。在（30±1）℃水温下,采用流速递增法,鲢的体长7.3～16.8 cm,体重6.10～66.50 g,按体长将鲢分为（8.17±0.59）cm、（10.09±0.53）cm、（11.84±0.67）cm、（13.94±0.68）cm、（15.90±0.64）cm共计5个试验组。结果表明,鲢的临界游泳速度为52～100 cm/s,相对临界游泳速度为5.90～7.14 BL/s,摆尾频率为98.7～432.2次/min。鲢的临界游泳速度随体长增加而增大,其线性拟合方程为Ucrit=4.908L＋17.63（R2=0.998）;其相对临界游泳速度随体长增加而减小,线性拟合方程为U＇crit=-0.130L＋8.025（R2=0.979）;在整个试验过程中,根据鱼类对水流速度的游泳行为响应,鲢摆尾频率随水流速度的增大而增加,两者呈线性关系;在相同流速下,较长个体鲢的摆尾频率显著小于较小的个体。

In hydraulic engineering,the fish passageway is regarded as an ecological corridor and its design is based on the critical swimming speed of target fish species. Populations of the four major Chinese carp species,the most common fish in China＇s rivers,have decreased sharply as the number of hydraulic engineering projects has increased. In order to explore the swimming ability of a carp species and provide a technical reference for the design of fish passageways,we carried out research on the swimming ability and behavior of silver carp（ Hypophthalmichthys molitrix）. Silver carp,in the weight range of 6. 10- 66. 50 g,were divided into five groups according to the body length（ BL） ：（ 8. 17 ± 0. 59） cm,（ 10. 09 ± 0. 53） cm,（ 11. 84 ± 0. 67） cm,（ 13. 94 ± 0. 68） cm,（ 15. 90± 0. 64） cm. The swimming ability and behavior of the silver carp were determined using a stepped-velocity test at（ 30 ± 1） ℃. The critical swimming speed（ Ucrit） of silver carp range was 52- 100 cm/s,the relative critical swimming speed（ U＇crit） vang was 5. 90- 7. 14 BL/s and the tail beat frequency（ TBF） range was 98. 7-432. 2 min- 1. Critical swimming speed increased linearly with body length,according to the equation,Ucrit=4. 908 L ＋ 17. 63（ R2= 0. 998）,but there was a negative linear correlation between the relative critical swimming speed and body length,U＇crit =- 0. 130 L ＋ 8. 025（ R2= 0. 979）. The tail beat frequency of silver carp increased linearly with flow velocity and,at a given velocity,TBF decreased with body length.