大口胭脂鱼鱼种的摄食节律和日摄食率

Diurnal feeding rhythm and daily food consumption of big mouth buffalo Ictiobus cyprinellus fingerlings

用肠饱满指数法测定了池养大口胭脂鱼Ictiobus cyprinellus鱼种的摄食节律与日摄食率。结果表明：大口胭脂鱼鱼种有明显的摄食节律，10：00—18：00为摄食高峰期，22：00摄食活动基本停止，6：00摄食强度明显回升，每天约有6h的停食时间。主要养殖季节6、7、8月，该鱼种的日摄食率（单位鱼体重每日的摄食量）分别为34．9、121．5、74．1g／（kg·d）。

Diurnal feeding rhythm and daily food consumption of big mouth buffalo Ictiobu, cyprinellu, fingerlings were measured by intestine filling index in Xindianwa of Yucheng City, Shandong Province, China from June to August 2000. The fish were sampled at 6：00, 10：00, 14：00, 18：00, 22：00, 2：00 and 6：00. The intestine filling index K was estimated according to the equation：K=10000Wf/Wb,where Wf is the weight of food in fish gut （g） and Wb is the weight of fish （g）. The daily food consumption Ko, i.e. the food weight per unit fish weight, was then calculated ：Kd=24Km/t,where Km is daily mean gut fullness and t is the gastric evacuation time （h）. t was 7 h for big mouth buffalo fingerlings based on indoor experiments. Big mouth buffalo fingerlings showed a clear diurnal rhythm in feeding. The feeding intensity peak was observed between 10：00 and 18：00, decreased after 18：00 and was minimum at 2：00. This indicates that light intensity in water column may be the dominant factor affeding the diurnal rhythm of the feeding in big mouth buffalo. The daily food consumption were 34.9,121.5,74.1 g/（ kg · d） in June, July and August, respectively.