水流对杂交鲟幼鱼游泳行为的影响

在26℃水温下,使用特制的鱼类游泳行为测定装置研究了杂交鲟(Huso duricusGeorgi♂×Acipenser schrenc-kiBrandt♀)幼鱼在0 m/s、0.1 m/s、0.3 m/s、0.5 m/s 4种流速条件下的游泳行为。结果显示:杂交鲟幼鱼随着流速的增加趋流率增大,且在90min内趋流率达到100%所需的时间明显缩短。实过过程中0.3 m/s和0.5 m/s两组摆尾频率都高于0.1 m/s和静水组,但在各个时段内,摆尾频率与趋流率均没有显著的相关。杂交鲟幼鱼的游泳状态明显受到所处流速的影响:0.1 m/s流速下以逆流前进为主,约占时间比例56.3%;0.3 m/s流速下以逆流静止为主,约占时间比例58.1%;0.5 m/s流速下以逆流后退为主,约占时间比例80.7%。在逆流前进和逆流静止两种游泳状态下,杂交鲟幼鱼的游泳速度和摆尾频率呈线性相关。但在逆流后退和顺流而下两种状态下,两者之间却没有显著的相关,且此两种状态下其游泳速度和摆尾频率随流速增加的变化趋势也不一致。

Effects of Water Current on Swimming Performance of Juvenile Hybrid Sturgeon(Huso duricus Georgi ♂ × Acipenser schrencki Brandt ♀)

Effects of water velocities(0,0.1,0.3,0.5 m/s)on swimming performance of juvenile hybrid sturgeon(Huso duricus Georgi ♂×Acipenser schrencki Brandt ♀)were investigated in lab at 26℃.The results showed that rheotactic frequency of hybrid sturgeon increased with the increasing of water velocity and the time for reaching 100% rheotactic frequency obviously shortened.The tail beat frequency at 0.3 m/s and 0.5 m/s was higher than that at 0.1 m/s and 0 m/s.There was no strong correlation between tail beat frequency and rheotactic frequency during each time phase in 90 minutes.Swimming state of juvenile Hybrid sturgeon was apparently affected by water current.At water flow 0.1 m/s the swimming state of fish gave priority to moving forward against the current about 56.3%;at water current 0.3 m/s the swimming state was mostly holding station against the current about 58.1%;at water flow 0.5 m/s,the swimming state was mostly moving forward against the current about 80.7%.There was a strong correlation between tail beat frequencies and swimming speed during the swimming states of moving forward and holding station.Nevertheless,during the swimming states of moving backwards and downstream,no significant relationship was found between them and the mutative trend of swimming speed and tail beat frequency differed.