STUDIES ON POPULATION DYNAMICS AND AXIMUM SUSTAINABLE YIELD OF CHINESE SNAKE-HEAD FISH,CHANNA ARGUS, IN THE LIANGZI LAKE

The population dynamics and maximum sustainable yield of Chinese snake-head fish, Channa argus, were studied based on 672 specimens taken from Liangzi Lake from March 1997 to February 1998.The scales were used for age determining and to growth back-calculating.The relationship between body length and scale radius can be expressed as L = 2.7683 + 9.0184S, and that between body weight and body length as W = 0.0126L3.0197.von Bertanlanffy growth equation was used for describing the growth of body length in relation to ages as Lt = 81.03 ?[l - e-0.1755(t+0.5690)] and the growth of body weight as Wt = 7310 ?[1 -e-0.1755(t + 0.5690)] 3.0197.Dominant age in catches was 3 years old.Total mortality of the population was estimated to be 0.5232, with 0.3049 in natural and 0.2182 in fishing mortality respectively.If the minimum age in catches could be controlled at 4 years old and the fishing mortality at 0.40, a maximum sustainable yield, which is 107% to the present, might be obtained.