不同光照周期下鲇仔鱼的日摄食节律

Diel Feeding Rhythm of Larval Silurus asotus in Different Photoperiods

水温23±1℃时,对鲇仔鱼自然光照、持续光照和持续黑暗下的日摄食节律研究表明,3种光照周期下,鲇仔鱼有明显的日摄食节律。持续光照与自然光照的日摄食节律基本一致,但持续黑暗与自然光照的日摄食节律不同;鲇仔鱼在自然及持续光照周期下均属典型的夜晚摄食类型,而在持续黑暗周期下不属于此类型;光照周期的改变对鲇仔鱼日摄食率的影响显著(P<0.05)。

The different photoperiods on the diel feeding rhythm of larval Silurus asotus at 23±1℃ were investigated. The fish were divided into 3 experimental groups： natural day-night group, continuous light group and continuous dark group. The results indicated that under the three photoperiods, they had continuous feeding characteristics in day and night, and revealed apparent feeding peak and feeding bottom at night and daytime respectively, and suggested that the larval Silurus asotus had obvious diel feeding rhythm. Moreover, the feeding rhythm of continuous light group was identical with that of the natural day-night group. However, the continuous dark group was different with the natural day-night group. The resuhs showed that the feeding rhythm of larval Silurus asotus in natural day-night group and continuous light group were identical with that of the night feeding. However, the continuous dark group were not. The change of photoperiod had significant effect on the the daily feeding ratio in natural day-night group （P 〈 0.05）.