梭鱼幼鱼食物通过消化道的时间

THE PASSAGE OF FOOD THROUGH THE ALLMENTARY CANAL OF YOUNG MULLET Mugil so-iuy Basilewsky

在鱼类生态学中,食物通过消化道的时间是研究摄食量的一个重要环节。在鱼类养殖业上,梭鱼(Mugil so-iuy Basilewsky)是受到我国和国际重视的对象之一。对其幼鱼进行这种观察,将有助于它们幼苗的摄食量和摄饵时间的确定。而关于这个问题的研究。

This observation was carried out both under natural condition and in the laboratory during the summer days in 1956 in Yantai with the following results and conclusions.Young mullet (2.1-2.7 cm body length) , being a plankton feeder, feed mainly on Paracalanus parvus and Cypris larvae, but other copepods, cladocera, crustacean larvae, lamelibranchia larvae and eggs of Engraulis japonica are also preyed on. They are greedy at evenings, the mean weight of their stomach contents is 0.032 gram, accounting for 8.8 percent of their body weight. The food passes into intestines from stomachs and most of them being excreted gradually out of the anuses within 12 hours i. e. the next morning. Two more hours later the remainings in the intestines are excreted thoroughly off the body.