绥芬河大麻哈鱼的生长分析

为了解绥芬河大麻哈鱼( Oncorhynchus keta Walbaum)的年龄、生长以及初次性成熟叉长情况。通过对2015 2017年采捕到的绥芬河大麻哈鱼洄游群体241个样本的鳞片观察和基础生物学测定,将其分为1 +、2 +、3 +、4 +、5 +五个年龄组,采用Von Bertalanffy生长方程模拟了大麻哈鱼不同性成熟年龄以及雌、雄个体间的生长,通过最大似然法估计模型的参数。残差平方和分析( ARSS)显示,绥芬河大麻哈鱼雌、雄个体间以及不同性成熟年龄组( 2 +,3 +)间的生长差异显著。采用Logistic曲线方程拟合了绥芬河大麻哈鱼的性成熟概率曲线,结果显示大麻哈鱼雌性个体的50%初次性成熟叉长( L 50 )比雄性大,ARSS分析结果表明不同年份间雌、雄个体的性成熟概率差异极其显著。此外,调查结果显示绥芬河大麻哈鱼的平均叉长有减小的趋势,且出现低龄( 1 +龄)个体。

Growth analysis of breeding Oncorhynchus keta in Suifen River

A total of 241 individual samples of Oncorhynchus keta were collected in autumn from 2015 to 2017 to study the age, growth and maturity probability of this species from Suifen River. Biological parameters of fork length and body weight were measured at the field, scales were taken into the laboratory for aging. Results showed the samples were divided into 1 +, 2 +, 3 +, 4 + and 5 + five age groups. Special Von Bertalanffy growth formula ( VBGF) was used to simulate the fork length growth of 2 + and 3 + age groups. A maximum likelihood estimation procedure was used to fit the function. Analysis of the residual sum of squares ( ARSS )was used to analyze the difference between different groups. The results suggested that significant differences were exited in growth between male and female individuals and between 2 + and 3 + age groups. The significant differences in growth of O. keta from different geographic populations ( Suifen River and Ussuri River) were also found in this study. Male and female individuals were analyzed independently. Logistic curvilinear equation was used to simulate the maturity probability of O. keta . The results showed that the fork length at 50% first sexual mature ( L 50 ) of female individuals were larger than male individuals. Meanwhile, the L 50 of O. keta from Suifen River in different collection year fluctuated significantly. The results of ARSS showed that there were significant differences in maturity probability between male and female individuals. In addition, the results showed that the average fork length of O. keta from Suifen River tended to decrease, and the young individuals ( 1 + age) were also detected.