3种鲟科鱼类生活史类型的研究

STUDY ON LIFE HISTORY PATTERN OF THREE Acipenseridae FISHES

根据ｒ－选择和ｋ－选择的典型特征以及通过渐近体长（Ｌ∞）、渐近体重（Ｗ∞）、生长系数（Ｋ）、初次性成熟年龄（Ｔｍ）、最大年龄（Ｔｍａｘ）、瞬时死亡率（Ｍ）和种群繁殖力（ＰＦ）等七个生态学参数值分析，可以判断３种鲟鱼类种群为典型ｋ－选择。应用平衡产量模式计算改变瞬时捕捞死亡率（Ｆ）和渔业补充年龄（Ｔｃ）时的产量变化，同样证实３种鲟科鱼类为典型的Ｋ型种群。作为渔业管理对策是严格控制捕捞强度，以保护渔业资源。

According to the typical characteristic of r-and k-selection and the given values of seven ecological parameters, namely, asymtotic body-length (L∞), asymptotic body-weight (W∞), growth coefficient (k), primary reproductive age (Tm), maximum age (Tmax), instantaneous natural mortality (M) and population fecundity (PF), the analyses of life-history patterns of fishes are carried out. It is concluded that the life-history pattern of A. sinensis,A. schrenckii and H. dauricus belongs in the typical of k-selection. Equilibriun yield model is applied to calculate the fish yield. When the instantaneous fishing mortality (F) is low, the yield curve goes up greatly, but declines rapidly when F is high. With the fishing recruit age (tc) changes, the yield increases to a maximun value at tc=11 (A. sinests) and tc=15 (A.schrenckii) and then decreases greatly with rising tc. Analysis of yield curves also demonstrates that the life-history pattern belongs to the typical k-selection. As a strategy of fishery management, if the harvesting strength can be controlled strictly, the fish resourses may be preserved.