官亭水库密鲴(Xenocypris davidi Bleeker)个体生殖力的研究

A STUDY OF INDIVIDUAL FECUNDITY OF THE XENOCYPRIS DAVIDI (BLEEKER) IN THE GUANTING RESERVOIR

本文研究了官亭水库104 尾产卵前成熟雌鱼的个体绝对生殖力(r),个体相对生殖力(r/L;r/W)与母鱼若干形态学指标的关系。密鲴个体绝对生殖力(r)和相对生殖力(r/L)与鱼体长(L)呈曲线相关,其回归方程为(r)=4232×10^(-7)L^(3.8444);它与纯体重的关系则为直线正相关,其回归方程为 r=496W-32630。研究结果表明:密鲴个体生殖力不但与体长、体重呈正相关,而且还不同程度地与成熟系数、鱼卵直径、肥满度和年龄成正相关关系。

This paper presents a preliminary analysis on the dynamics and characters ofindividual fecundity of the Xenocypris davidi (Bleeker) in Guanting reservoir. Ma-terials were collected in 1982, 104 samples were studied, the results are summarizedas follows:1. The individual absolute fecundity (r) varied between 42177 and 265949(egg)(average, 115769); the individual relative fecundity r/L varied between 156 and799 (eggs/mm) (averagr, 414) and r/W between 127 and 447 (eggs/g) (average,387).2. The variability is shown in diagrams of fecundity and body--length, body--weight and age groups in Figs 1--5.The relationship between the individual absolute fecundity (r) and length (L) isindicated by the exponential equation: r= 4231×10^(-7)L^(3.3444), (S_b=0.3045, ρ<0. 001).The relationship between the individual absolute fecundity (r) and body weight(W) is expressed by the following equation: r = 496W-32630, (S_b=33.43,ρ<0. 001)3. The fecundity coefficient (C=L.W/r) varied between 0. 5 and 1. 74(mm.g/eggs), mostly between 0.6 and 0.9 (mm.g/eggs).The individual absolute fecundity (r) was found to be related to 'L.W' and'(L·W)^(1/2)' linearly, it also likely relates between individual fecundity (r,r/L) andbody--weight.4. The individual fecundity (r, r/L) not only increases with increase of lengthand weight, but also varies with the peculiarity of maturation coefficient, eggs diame-ter, age and the coefficient of condition (K= W/L^8×100): among these morphologi-cal indices, body weigh is the most distinct and followed by the length, maturationcoefficient,eggs diameter, coefficient of condition (K) and the age at the last.