长江鲥鱼种群生长和繁殖特性的研究

STUDIES ON THE GROWTH AND REPRODUCTION CHARACTERISTICS OF CHANGJIANG RIVER REEVE'S SHAD POPULATION

本文研究了长江鲥鱼的生长参数和繁殖特性:(1)采用Von Bertalanffy生长方程计算长江鲥鱼的生长,求得渐近体长值L_∞()=58.12厘米,L_∞()=52.22厘米,渐近体重值W_∞()=2874.64克,W_∞()=1989.99克,生长拐点t=1.7年,t=1.3年。(2)长江鲥鱼主要集中在赣江产卵,产卵时的水温为24.2—33.5℃,流速为0.31—1.52米/秒。(3)分析和比较了长江鲥鱼不同年际间种群数量和繁殖群体结构的特点,指出性成熟年龄提前是鲥鱼资源衰退的主要标征。

This paper deals with the growth and reproduction characteristics of Changjiang Reeve's Shad population. The study shows that the growth of Changjiang Reeve's Shad can be calculated by Von Bertalanffy growth equation. Its nearing body length L8888888888888888(femalt) is 58.12 cm, L888888888888 (male) 52.22cm. Its nearing body weight W8888888888888888(female) is 2874.64g, W88888888888888 (male) 1989.99g. Its growth turning point T (female) is 1.7 yr, T (male) 1.3 yr. Changjiang Reeve's Shad spawns mainly in Ganjiang River. The water temperature during the spawning period is 24.2 to 33.5cccccccccccccccccccc. The current velocity at that time is 0.31 to 1.52m/s. By analysing and comparing the population sizes and the structure characteristics of reproductive population of Changjiang Reeve's Shad in different years, we conclude that the main sign of the resources depletion of Changjiang Reeves Soad Is the sexual prematurity.