长江中、上游铜鱼的生长特性

铜鱼是长江中上游的重要经济鱼类和天然捕捞对象,1990—1995年作者利用在长江中上游收集的1030尾标本,对铜鱼的生长特性进行了研究。其体重和体长的关系为W=0.005413L~(3.113)(r=0.9982),生长方程为L_t=60.02291-e~(-0.2325(t 0.6108))];W_t=3261.91371-e~(-0.2325(t 0.6108))]~(3.113),体重生长拐点t=4.2龄,相应的体长41.05cm、体重973.03g。按生长指标值分析,阶段生长可明显地划分为两个时期,即4龄前的生长迅速期和4龄后的生长减缓期。因此,天然渔业的捕捞规格应控制在约1000g以上的个体,目前在葛洲坝以下的中游江段主要捕捞幼鱼的现状应该改变。

GROWTH CHARACTERISTICS OF COREIUS HETERODON IN THE MIDDLE AND UPPER REACHES OF THE YANGTZE RIVER

Coreius heterodon is a very important commercial species in the middle and upper reaches of the Yangtze River. No special report on the research in the growth characteristics of the fish is available so far. In this paper, one thousand and thirty specimens, which were collected from the middle and upper reaches of the Yangtze River during the years of 1990-1995, were investigated on the fish's growth biology. By means of biostatistics analysis, the relationship between body length, W(g), and body weight, L(cm), may be expressed as W = 0.005413L3.113(r = 0.9982). The von Bertalanffy equations for the species are as follows Lt=60.0229 1-e-0.2325(t 0.6108)], and Wt=3261.91371-e-0.2325(t 0.6108)] 3.113. The growth inflection point is at t = 4. 2, corresponding to L = 41.05cm, and W = 973.03g. The data obtained infer that the fish grows much faster before 4 years of age than does after 4 years of age. The varieties of growth index also show the same trend. Based on the research results, we suggest that the catchable size of the fish from the Yangtze River should be above 1000g with the aim of rational utilization and protection for the resources of fish.