珠江斑鱯的食性

根据对珠江斑鱯的资源调查结果,从饵料生物种类组成、出现频率、不同体长斑鱯的食物组成差异、食性的季节变化等方面研究了珠江斑鱯食性特点。表明天然水域中斑鱯主要以甲壳类、昆虫类、鱼类、环节动物、植物碎屑等为食,其中甲壳类的出现频率高达78．6％,水生昆虫的出现频率为45．8％。其食物类群的季节变化明显,但没有出现停止摄食的时期,斑鲼在春季的摄食强度最大,各类食物在春季出现的频率均高于其它季节,斑鱯摄食率和充塞度的季节变化是一致的。不同体长斑鱯的饵料有一定的转化或更替阶段,约170mm体长时为主要饵料转化的第一阶段,约240mm体长时为主要饵料转化的第二阶段,随着斑鱯体长的增长,其摄食饵料的个体变大,但种类减少。

Feeding habits of Mystus guttatus in the Pearl River

This paper reports the feeding habits of Mystus guttatus in the Pearl River with natural resources investigation. The reports include feed fullness, feed composition, frequency of feed occurrence and variation of feed composition in different seasons was also studied. The investigation result shows that the feed of Mystus guttatus in the Pearl River are crustaceans, insect, annelida, fish and pieces of plant. Among them, the crustaceans and insects are the main feed,the emergence frequency is 78.6% and 45.8% respectively. In different seasons, the variety of feed composition is markedly different, and no pause of feeding. The feed of Mystus guttatus changed with the different body length of the fish. The first feed change period was at about 170mm body length and the second at about 240mm body length. It is getting simpler as Mystus guttatus grows up.