黑龙江乌苏里白鲑的个体繁殖力

2013年和2014年的10–11月,在黑龙江抚远江段采集成熟度为IV期的雌性乌苏里白鲑(Coregonus ussurinsis)133尾,鉴定年龄(A),测量叉长(L)、体重(W)、净体重(Wn)和卵巢重(Wo)等生物学指标。计算了绝对繁殖力(F)、叉长相对繁殖力(FL)、体重相对繁殖力(FW)、性成熟系数(GSI)和肥满度(K),并运用6种数学模型及多元线性逐步回归方程拟合了乌苏里白鲑个体繁殖力与生物学指标之间的关系。结果表明,用于统计繁殖力的样本由4+~8+龄5个年龄组组成,乌苏里白鲑F分布范围在1.161×104~5.921×104粒,平均为3.027×104粒;FL分布在307.13~1119.4 eggs/cm,平均为622.5 eggs/cm;FW分布在19.81~56.98 eggs/g,平均为34.62 eggs/g。F与叉长、体重和年龄拟合度最高的函数分别为幂函数、线性函数和抛物线,FL与叉长、体重和年龄分别为幂函数、幂函数和线性函数相关,而FW与叉长、体重和年龄无显著相关性,FW只与卵巢重和性成熟系数具有一定的相关性,且拟合度最高的方程均为幂函数。多元线性逐步回归分析表明,乌苏里白鲑F与卵巢重、叉长和性成熟系数显著相关,而FL和FW均受卵巢重和性成熟系数的显著影响,从二者偏相关系数值来讲,卵巢重与个体繁殖力(F、FL、FW)之间的相关性均高于性成熟系数。

Fecundity of Coregonus ussuriensis in the Heilongjiang River, China

Fecundity of <i>Coregonus ussuriensis</i>, collected during October and November 2013-2014 in the Heilongjiang River, China, was studied. Fish age was determined by scales, fork length, body weight, net body weight, and ovarian weight. The ages of the specimens were 5⁺-8⁺ years. Individual absolute fecundity was determined by the gravimetric method and was used to calculate relative fecundity per centimeter, relative fecundity per gram, gonadosomatic index, relative fatness, and other indices. Individual fish absolute fecundity was 1.161&#215;10⁴-5.921&#215;10⁴eggs (mean, 3.027&#215;10⁴ eggs). Relative fecundity per centimeter was 307.13-1119.37 eggs/cm (mean, 622.5 eggs/cm. Relative fecundity per gram was 19.81-56.98 eggs/g (mean, 34.62 eggs/g). The relationships between absolute fecundity and fork length, body weight, and age were regressed with a power function, linear equation, and a parabola. The relationships between relative fecundity per centimeter and fork length, body weight, and age were described by a power function and a power function and linear equation. Relative fecundity per gram was not correlated with fork length, body weight, or age but was correlated with gonadosomatic index and ovarian weight, using the power function as the best fit. A multiple regression analysis revealed that individual absolute fecundity was significantly correlated with ovarian weight and fork length, while relative fecundity per centimeter and relative fecundity per gram were significantly correlated with ovarian weight and gonadosomatic index. The correlation between individual fecundity and ovarian weight was higher than that with the gonadosomatic index based on the partial correlation coefficient.