惠东拟囊腔吸虫种群动态研究

Population dynamics of Saccocoelioides huidongensisin Mugil cephalus

鲻体内的惠东拟囊腔吸虫 (SaccocoedioideshuidongensisL櫣 ,1993)随着宿主体长的生长 ,其感染强度、平均密度有逐渐增加的趋势 ,而感染率则呈不规则的波动 ;其感染率、感染强度和平均密度在不同月份亦呈不稳定变化 ;吸虫在宿主体内的频率分布表明 ,大量的吸虫寄生于少数宿主中 ,而多数宿主感染少量的吸虫 ;吸虫在不同体长组的分布类型为聚集分布 。

The samples of Mugil cephalus were caught along the coast of Huangfu in Yuedong area,Guangdong Province from December 1991 to Novmber 1992. The samples were divided into 7 groups in body length, which were 30～50, 50～70, 70～90, 90～11 0, 110～130, 130～150 and >150 mm groups, and the prevalence, infecting intensity, mean abundance and frequency distribution of Saccocoelioides huidonggensis, a kind of intestine-parasitic trematode, were observed. The results showed that the relative intensity of infection and the mean abundance of infection were positively correlated with the body length of the host (M. cephalus),but the prevalence changed irregularly in different body length groups of the host. The longer the body length, the higher the relative intensity of infection, and so was the mean abundance of infection. No obvious changes of prevalence, relative intensity and mean abundance of infection were found in seasonal pattern. A large number of trematodes were found in a very small number of hosts, and most hosts were infected with less parasites. The distribution of the trematodes in the host of different body length groups and in different seasons showed an aggregate distribution.