光照对川陕哲罗鲑受精卵孵化的影响

Effect of illumination on the hatching of Sichuan taimen(Hucho bleekeri Kimura) eggs

为了解光照强度和光照周期对川陕哲罗鲑(Hucho bleekeri kimura)受精卵孵化的影响,设置4个不同光照条件(24 h黑暗、12 h黑暗∶12 h强光、24 h强光、24 h弱光),比较川陕哲罗鲑受精卵的孵化率和孵化时间。结果显示:川陕哲罗鲑均保持较高的孵化率,其中,24 h黑暗组的孵化率为(63.75±3.31)%,显著低于其他3个试验组;24 h弱光组的孵化率为(82.08±2.60)%,显著高于其他3个试验组。在不同发育阶段,各个试验组的川陕哲罗鲑受精卵死亡率高度一致,死亡较高的时期主要集中在细胞期-囊胚早期和孵化期。从孵出时间来看,24 h黑暗组和24 h弱光组的孵出时间略早于其他2个试验组,各组分别历时23.5 d(24 h黑暗)、25.5 d(12 h黑暗∶12 h强光)、25.5 d(24 h强光)和24.5 d(24 h弱光)完成整个胚胎发育过程。

Illumination is an important environmental factor which influences the hatching of fertilized eggs of fish.This research investigated the effect of light intensity and light cycle on fertilized eggs hatching of Sichuan taimen ( Hucho bleekeri Kimura).The hatching rate and hatching time of the fertilized eggs of the H.bleekeri were compared under the conditions of four different light settings ( 24 hrs dark,12 hrs dark:12 hrs light,24 hrs intense-light,and 24 hrs low-light).The results indicated that all test groups presented the high hatching rates of the H.bleeker .Among them,the hatching rate of the 24 hrs dark group was ( 63.75±3.31)%,which was significantly lower than other three experimental groups.Oppositely,the hatching rate of the 24 hrs low-light group was ( 82.08±2.60)%,which was significantly higher than other three test groups.The mortality rate of fertilized eggs of the H.bleekeri was highly consistent among the all experimental groups at different developmental stages,with the higher deaths mainly concentrating in the early stages of the experiment and incubation period.The 24 hrs dark group and 24 hrs low-light group was slightly earlier than the other two test groups.Each group lasted 23.5 days ( 24 hrs dark),25.5 days ( 12 hrs dark:12 hrs intense-light),25.5 days ( 24 hrs intense-light)and 24.5 days ( 24 hrs low-light)to complete the entire embryonic development process.