黄鳝体内新棘衣棘头虫种群季节动态与分布

Seasonal Dynamics and Population Distribution of Pallisentis(Neosentis) celatus in Monopterus albus

通过对鄱阳湖黄鳝体内新棘衣棘头虫感染情况的调查,结果发现在870尾黄鳝中,有231尾黄鳝的消化道中有棘头虫感染,感染率为26.5%,丰盛度为9.79±13.9。不同月份之间黄鳝体内新棘衣棘头虫的感染率存在显著的差异(P<0.005);感染率在11、12和1月出现3个峰值,分别为55.7%、48.5%和44%,而2月份的感染率最低,为11.2%。5月份的丰盛度最高,达到22.71±13.90;2月份的丰盛度也最低,为3.00±1.27。不同体长组黄鳝体内棘头虫的感染率存在极显著性差异;其中体长为55.1～60.0cm的黄鳝体内棘头虫的感染率最高,体长小于21cm的黄鳝没有新棘衣棘头虫感染。棘头虫感染与未感染黄鳝之间的肥满度没有显著的差异。另外,利用比值衡量与负二项分布拟合证明棘头虫在黄鳝消化道内呈聚集分布。

The infection of the Pallisentis （Neosentis） celatus was investigatied in the host Monopterus albus from Poyang Lake. 870 Monopterus albus were selected to examine. The results indicated that 231 Monopterus albus were infected with Pallisentis （Neosentis） celatus in their dignificant tract. The prevalence was 26.5% ,and the abundance was 9.79±13.9. The prevalences of Pallisentis （Neosentis） celatus in Monopterus albus among different months had significant differences（P〈0. 005）. Three peak values of prevalence were found in November （55.7 %）, December （48.5 %） and January （44 %）, while the lowest prevalence was 11.2% in February. The highest abundance was 3.00± 1.27 in May,and the lowest abundance was in February. Sigificant differences were observed in the prevalence of Pallisentis （Neosentis） celatus with relation to different lengths of Monopterus albus. The highest prevalence in the Monopterus albus with body length between 55.1 cm and 60.0 cm. The Pallisentis （Neosentis） celatus was not discovered in the Monopterus albus with body length less than 21 cm. No significant differences of the fatness were found between Pallisentis （Neosentis） celatus infecting and non infecting Monopterus albus. In addition,the result from the fitting of the ratio measurement and negative binomial distribution proved that Pallisentis （Neosentis） celatus was over dispersed in the digestive tract of Monopterus albus.