不同光照周期下鲇幼鱼的日摄食节律

Diel Feeding Rhythm of Juvenile Oriental Sheatfish Silurus asotus in Different Photoperiods

水温(23±1)℃,研究了鲇幼鱼自然光照、持续光照(自然光或日光灯作光源)和持续黑暗条件下的日摄食节律。试验结果表明,3种光照周期下,鲇幼鱼昼夜均有连续摄食特性,期间具有明显的摄食高峰(夜间)和低谷(白天),鲇幼鱼有明显的日摄食节律;持续黑暗与自然光照周期下的鲇幼鱼日摄食节律基本一致,持续光照与自然光照周期下的鲇幼鱼日摄食节律有所差异。研究证明,鲇幼鱼在3种光照周期下均属于典型的夜晚摄食类型;光照周期的改变对鲇幼鱼的日摄食率无显著影响(P>0.05)。

Effect of different photoperiods on the diel feeding rhythm of juvenile oriental sheaffish Silurus asotus was studied at （23 ± 1 ） %. The fish was divided into three experimental groups ： natural day-night group, continuous light group and continuous dark group. The results showed that during three photoperiods, they had continuous feeding characteristics in day-night. An apparent feeding peak and minimum was obversed at night and in daytime respectively,indicating that the juveniles had obvious diel feeding rhythm. Moreover, the feeding rhythm in the continuous dark group was identical with the natural day-night group. However, the continuous light group was different with the natural day-night group. The results showed that the feeding rhythm of the juveniles in three groups were identical with the night feeding. There was no significant effect of change in photoperiod-continuous light or continuous dark on the daily feeding ratio in natural day-night group （ P 〉 0.05 ）.