外睾吸虫种群动态研究

外睾吸虫(Exorchis sp.)是控制日本血吸虫(Schistosoma ja ponicum)在其宿主钉螺(Oncomelania hupensis)体内发育的一个有利用价值的生物资源.掌握外睾吸虫种群的变化规律,对于进一步研究血吸虫病的生物防治有着重要的意义.对鲶鱼(Silurus asotus)肠道内寄生的外睾吸虫的种群动态进行研究,研究结果表明,不同月份外睾吸虫在鲶鱼体内的感染率、种群平均密度和感染强度无明显的变化规律.外睾吸虫在不同体长宿主体内的感染率变化范围在65.38％～91.98％,宿主体长在270mm以下时,外睾吸虫的感染率随着宿主体长的增加而逐渐增大.外睾吸虫在宿主体内的频率分布表明,多数宿主只感染少量的外睾吸虫,而较大量的外睾吸虫只感染少数的宿主.吸虫种群在不同月份和不同体长宿主体内的分布类型均属于聚集分布,在不同体长组宿主中聚集强度随着种群密度增加而增强.

Population Dynamics of Exorchis sp.

Exorchis sp.could be a valuable biological resource in control over the development of Schistsoma japonicain in Oncomelania hupensis.Understanding the change rule of Exorchis sp.population is significant to the further research on biological control of schistosomiasis.The population dynamics of Exorchis sp.parasiting in the intestines of Silurus asotus was reported.The results indicated that the prevalence,mean density and mean intensity of infection changed irregularly in host in different months in a year.The prevalence fluctuated from 65.38% to 91.98% in host of different body lengths,and increased with the increasing of body length of host less than 270 mm.The frequency distribution of Exorchis sp.in host indicated that most hosts were infected with less parasites.The population distribution of Exorchis sp.parasiting in the host in different months and of different body lengths all showed aggregated distribution.The degree of aggregation increased with the increasing of mean density of parasites in host of different body lengths.