常德稻田黄鳝感染胃瘤线虫的研究

Study on Infection of Monopterus Albus by Eustrongylides sp.Paddy-field in Changde City,Hunan

研究了5月份沅水下游常德稻田所产黄鳝对胃瘤线虫幼虫的感染情况.结果表明,其感染率为77.3％,感染强度为6.08,平均丰度为4.70;黄鳝的感染与其自身的体长有一定关系,感染率在体长201-350mm范围内的黄鳝高达80％以上,感染强度在体长301-350mm范围内的黄鳝为最高(11.0个/尾),而体长大干350mm的黄鳝,其感染率和感染强度均有所降低,这可能与黄鳝对胃瘤线虫的感染产生免疫力有关;胃瘤线虫种群在黄鳝中呈聚集分布,其负二项参数k=0.9915;胃瘤线虫种群主要由体长41-60mm的个体组成.

The infection condition of Dusrongylides sp. (larva) in its host Monopterus albus from paddy - field was studied in Changde city, Hunan on May 2002. This result showed that the prevalence was 77.3 %, the mean intensity was 6.08 and the mean abundance was 4. 70. The infection condition was positively correlated with the body length of the host Monopterus albus .There were higher prevalence( up to 80%) in the finless eels 201 - 350mm length body,the mean intensity were highest(11 .0) in the finless eels 301 - 350mm length body, and there were lower prevalence and mean intensity above 350mm length body of the finless eels. The change was probably related to the immune response of host fsth infected by the nematode( larve) . The frequency distribution of the nematode( larva) was over- dispersed among the fish population.Its parameter of negative binomial distribution wask: 0. 991 5. The population of Eustrongylides sp. was mainly composed of worm 40 - 60mm length body.