鄱阳湖鳜鱼的生物学

研究了鄱阳湖鳜鱼（翘嘴鳜）的生长、食性、性腺发育及形态特征。鄱阳湖鳜鱼的年龄组成以第二、三年为主，占８５％。雌性鳜鱼的生长速度在各龄中均比雄性的要快。鳜鱼体长与体重呈曲线回归，关系式为Ｗ＝０．０２２５２Ｌ３．０９２４。鳜鱼在鄱阳湖无明显停食期，属终年摄食鱼类，食物主要为鲤、鲫、虾等。食物鱼长度平均为６．６ｃｍ，最大不超过１２ｃｍ。性腺发育呈现明显的周年变化。雌性鱼成熟系数周年变化在０．７９％～１０．０７％，雄性在０．２４％～３．８３％，两者均在４、５月达到最大，以后减小。成熟年龄雌鱼为２冬龄，雄鱼为２夏龄。

Biology of Mandarin Fish (Siniperca chuatsi Basilesky) in Poyang Lake

The paper studies the growth, food preference, gonadal development and morphological characteristics of mandarin fish (Siniperca chuatsi Basilewsky) in Poyang Lake, of which the two or three-year-old take up 85 percent. The results show that the female mandarin fishes grow faster than the male at all growth periods, and there is curve regression relationship between the body weight (W) and standard lenth (L) with relational expression as follow: W=0.022 52L 3.0924 . In Poyang Lake mandarin fishes looked for food in whole year, and their main food fishs, whose standard length averages 6.6cm and is less than 12cm, include crucian carp, common carp and shrimps, etc. There is obvious periodic change in gonadal development of mandarin fish. Gonadosomatic index of the female and that of the male range from 0.79% to 10.07%, from 0.24% to 3.83% respectively, reaching the highest in April or May and decreasing Later. The female attains maturity at two-winter-age and the male at two-summer-age.