持续水流刺激对青鱼幼鱼体型特征的影响

The Effects of Continuous Water Flow on the Body Shape Features of Juvenile Mylopharyngodon piceus

为了考察持续水流刺激对青鱼幼鱼体型特征的影响,在(25±0.5)℃水温条件下,将大小相当的144尾体质量为(11.90±0.24)g、体长为(8.94±0.31)cm的实验鱼随机分为对照组、9cm/s、18cm/s和36cm/s处理组,分别在不同水流速度下处理8周.随后从各组中各随机挑选12尾实验鱼,测量分析其体型特征参数变化.结果显示:9cm/s处理组的头长和头长/体长显著大于对照组(p<0.05);18cm/s处理组的头长、头高、体高、叉长、鱼体侧面积和头长/体长显著大于对照组(p<0.05);36cm/s处理组的头长、头高、尾柄下侧长度、尾柄侧面积、头长/体长和尾柄侧面积/鱼体侧面积显著大于对照组(p<0.05),其他形态参数较对照组无显著差异.结果表明:持续水流刺激显著影响了青鱼幼鱼的体型特征;高流速(36cm/s)刺激下青鱼幼鱼的尾柄面积显著增加,这可能有利于其游泳能力的改善.

To investigate the effects of continuous water flow on the body shape features of juvenile Mylopharyngodon piceus,144fish（body mass：11.90±0.24 g,body length：8.94±0.31cm）were randomly divided into four groups（control group,9cm/s treatment group,18cm/s treatment group and 36cm/s treatment group）.Fish in the four groups were forced to swim against different water velocities for 8weeks at a constant temperature of（25±0.5）℃.Then,the morphological images and related parameters of the juvenile M.piceus were measured and calculated after 8weeks.The fish in 9cm/s treatment group displayed significant increase in head length（HL）and HL/body length（BL）ratio compared with the fish of control group（P〈0.05）.The fish in 18cm/s treatment group displayed significant increase in HL,head depth（HD）,body depth（BD）,fork length（FL）,the side area of body（Ab）,and HL/BL ratio compared with the fish of control group（P〈0.05）.The fish in 36cm/s treatment group displayed significant increase in HL,HD,the length of the lower side of caudal peduncle（Llc）,side area of caudal peduncle（Acp）,HL/BLratio and Acp/Abcompared with the fish of control group（P〈0.05）.Continuous flow stimulation showed no effect on the other morphological parameters when compared to the control group.These results suggested that（1）the body shape features of M.piceus were impacted by the continuous flow stimulation;（2）high water velocity（36cm/s）resulted in a significant increase in relative Acp and Ab,which may be beneficial to the improvement of swimming performance in juvenile M.piceus.