寄生于大鳍鳠的鳠鱼鳋的生态研究

STUDIES ON ECOLOGY OF Ergasilus hemibagri PARASITIZING Mystus macropterus

鱯鱼鳋能在16℃以上的适宜水温中繁殖,在25℃左右,繁殖快,感染力强;鱯鱼鳋的感染有明显的季节变化,这是由外界因素(如水温、水质和水体流速等)的变化以及它的繁殖和感染力的变化所引起的;鱯鱼鳋的频数在宿主种群中呈负二项分布;鱯鱼鳋的感染可能引起大鳍鱯产生抵抗力,抵抗力的强度随感染次数和感染强度增加而增强;在天然条件下,影响鱯鱼鳋种群消长的主要因素是非密度制约因素和大鳍鱯的免疫反应。

From January, 1987 to January, 1988, the ecological aspects of Ergasilus hemibagri (Cyclopoida), which is parasitic on the gill of the fish -Mystus macropterus in the Fujiang River of Hechuan County, China, have been studied. The conclusions can be drawn as following: the parasite can reproduce above 16℃ and it possesses high reproduction and efficiently infective power about 25℃; the infections of the parasite varied seasonally as some factors changed, such as temperature, water quality, current velocity, the reproduction and infective power of the parasite etc; the frequency distribution of the parasite is negative binomial distribution, which is fit, when tested with chi square test; it is probable that the host produces resistance against the parasite when it is infected by the parasite, and the resistance increases with the increase of the number of infection and intensity; in natural environment, the factors influencing the population growth of the parasite are density of independent factors and immunological responses generated by the host.