褶纹冠蚌寄生蚌螨群落结构

通过对太湖、巢湖、鄱阳湖中褶纹冠蚌寄生蚌螨的感染调查，发现3个湖泊的褶纹冠蚌中有3种蚌螨寄生，但蚌螨群落组成不同。弯弓蚌螨是巢湖的绝对优势种，优势度指数为99．7％；太湖的优势种是Y纹蚌螨，优势度指数70．3％，次优势种为弯弓蚌螨，优势度指数23．4％；鄱阳湖优势种是Unionicola spp，优势度指数52．4％，次优势种为弯弓蚌螨，优势度指数29.5％。蚌螨在宿主褶纹冠蚌内都呈聚集分布，但3个湖泊中不同种寄生蚌螨的分布参数不同，说明其聚集强度不同。利用卡方对种间关联关系进行检验，结果表明鄱阳湖中Y纹蚌螨与弯弓蚌螨之间呈负关联关系（x^2=5．95〉x0.05^2 =3，84，V=-0．57），弯弓蚌螨与Unionicola spp．呈正关联关系（x^2=4．22〉x0.05^2=3．84，V=0．48）。由群落相似系数可以看出3个湖泊寄生蚌螨群落相似程度较低。

STUDIES ON THE COMMUNITY ECOLOGY OF UNIONICOLID MITES FROM CRISTARIA PLICATA

Three species of unionicolid mites were collected trom Cristaria pltcata in Taihu LaKe ,Chaohu LaKe and Poyang Lake,but the component communities of these mites were different among three Lakes. Unionicola arcutata was absolutely dominant species in Chaohu Lake, and dominance index was 99.7%. U. ypsilophora was dominant species and U. arcutata is subdominant species in Taihu lake, dominance index were 70.3% and 23.4% , respectively. Unionicola spp. was dominant species and U. arcutata was subdominant species in Poyang Lake, dominance index were 52.4% and 29.5%, respectively. The distribution parameters for these mites in different Lakes were va- rious. Analysis for interspecific association indicated that it was obviously negative association between U. ypsilophora and U. arcutata,but it was positive association between U. arcutata and Unionieola spp. in Poyang Lake. However,without distinct association was observed between others species in Taihu and Chaohu Lake.