中文摘要：

为了了解天鹅湖不同微生境条件下底栖贝类的群落结构及时空分布特征,于2013年12月至2014年11月,对天鹅湖矮大叶藻区、空白区、大叶藻区边缘及其内部的底栖贝类和环境特征进行了调查。共发现15种大型底栖贝类,隶属14科15属;贝类种类组成、分布密度、生物量以及物种多样性指数在4种生境中差异显著,但均无明显的季节变化。空白区域中贝类总密度和单位面积生物量最高,大叶藻区内部最低,但矮大叶藻区和大叶藻区内部多样性指数较高。大叶藻区内部的贝类以腹足类锈凹螺、日本月华螺、刺绣翼螺等刮食者为主,而双壳贝类则更倾向于选择无海草覆盖的空白区或者海草较为稀疏的草场边缘。综合分析表明,天鹅湖底栖贝类的分布和多样性受底质特征和海草覆盖影响最为显著,同时与水深密切相关。

英文摘要：

To understand the community structure as well as the spatial and temporal distribution of macrobenthic molluscs at different microhabitats in Swan Lake,we investigated the molluscan community and environmental factors at four types of microhabitats(Zostera japonica beds,bare area,edge of Zostera marina L.beds,and interior of Z.marina L.beds)from December2013to November2014.Fifteen molluscan species belonging to14families and15genera were recorded.The species composition,abundance,biomass,and biodiversity of molluscan communities exhibited significant differences among the transects but no clear difference among the seasons.The maximum abundance and biomass of molluscs were found in the bare area,whereas the minimum was found in the interior of Z.marina L.beds.The species diversity index of molluscs was higher in the Z.japonica beds and internal Z.marina L.beds than in the other two transects.The dominant molluscs in the internal Z.marina L.beds were gastropod grazers,such as Chlorostoma rustica,Haloa rotundata,and Alaba picta.However,bivalve molluscs were more likely to choose the bare area without vegetation or the edge of Z.marina L.beds with sparse seagrass.Comprehensive analysis revealed that the community structure and distribution of molluscs were closely related to seagrass,sediment characteristics,and water depth.