【摘要】 对长江上游圆口铜鱼幼鱼肠道内寄生小吻虫种群生态的研究表明,长江上游圆口铜鱼幼鱼体内小吻虫感染率为69·88%,感染强度8·18(1~47),相对密度5·72。雌鱼的感染率和感染强度均高于雄鱼,体长4·0~5·9cm的圆口铜鱼被小吻虫的感染率最高,且染虫对肥满度有显著影响。小吻虫在圆口铜鱼幼鱼种群中呈负二项分布,66%的虫体集丛分布在圆口铜鱼肠道的前段,其种群主要由5mm以下个体组成,雌虫明显多于雄虫。更多还原

【Abstract】 Population ecology of Micracanthorkynchina motamurai in Coreius guichenoti in the upper reach of Yangtze River was investigated in the paper.166 Coreius guichenoti caught from May to July,2003 were examined.The results showed that among all the examined fish,the infection rate was 69.88%,the infection intensity was 8.18,and the relative density was 5.72.The female fish were more vulnerable to M.motamurai than the male.The fish with a body length of 4～5.9 cm were the most easily to be infected which drastically affected their relative fatness.The frequency distribution of the parasite was negative binomial distribution in the fish population.The parasite were clustered at the forepart of the intestine which mainly composed of individuals with a length below 5.0 mm.The female parasites were much more than the male.更多还原