野生与人工养殖鲫鳃部寄生指环虫的群落结构

为了阐明养殖环境对鱼类寄生指环虫群落的影响，研究调查了湖北省梁子湖和湖北省石首市养殖池塘中鲫鳃部寄生指环虫的种类和感染情况。在梁子湖中的野生鲫共发现6种指环虫，分别为坏鳃指环虫（Dactylogyrus vastator）、中型指环虫（D. intermedius）、弧形指环虫（D. arcuatus）、弓茎指环虫（D. baueri）、美丽指环虫（D. formosus）、望外指环虫（D. inexpeatatus）；在养殖池塘中，除了望外指环虫外，其他5种指环虫均有发现。分析结果表明，来自于梁子湖野生鲫鳃部的坏鳃指环虫的平均丰度以及其他4种指环虫（不含望外指环虫）的感染率与平均丰度明显高于养殖池塘的。梁子湖中的指环虫群落平均物种丰富度、平均寄生虫数量以及Brillouin多样性指数都明显高于养殖池塘的；梁子湖野生鲫寄生指环虫的优势种是弧形指环虫（0.54），而池塘中的是坏鳃指环虫（0.76）。在宿主密度、种群大小、光照和溶氧等影响指环虫群落的因子中，溶氧可能是最主要因子。  

COMMUNITY STRUCTURE OF THE DACTYLOGYRUS SPECIES ON THE GILLS OF WILD AND CULTRUED CRUCIAN CARP (CARASSIUS AURATUS)

The species and infection levels of Dactylogyrus on the gills of crucian carp (Carassius auratus) were investigated in Liangzi Lake and a fish cultured pond in Shishou city to determine the effects of the culture environment on the community structure of the Dactylogyrus species. Six Dactylogyrus species were identified on the gills of cucian carp in Liangzi Lake, including Dactylogyrus vastator, D. intermedius, D. arcuatus, D. baueri, D. formosus and D. inexpeatatus. With exception of D. inexpectatus, the other five species of Dactylogyrus were also found in the fish cultured pond. The mean abundance of Dactylogyrus species was higher in Liangzi Lake than that in the pond. Apart from D. vastator, the prevalence of other four Dactylogyrus species (not including D. inexpeatatus) in Liangzi Lake was higher than that in the fish pond as well. Mean richness, mean number of individual and Brillouins index were also higher in Liangzi Lake than that in the fish pond. The dominant species was D. arcuatus (0.54) in Liangzi Lake while D. vastator (0.76) in the fish pond. Of the factors affected Dactylogyrus community, such as fish density, population size, light and dissolved oxygen, dissolved oxygen was considered as the most important factor.