PREDATION OF LEPTODORA KINDTI FOCKE (CRUSTACEA, CLADOCERA) ON DIAPHANOSOMA BRACHYURUM AND MOINA MICRURA IN DONGHU LAKE, WUHAN

Abstract

本文在室内模拟自然水温研究了东湖透明薄皮溞（Leptodora Kindti）对优势枝角类短尾秀体溞（Diaphanosoma brachyurum）和微型裸腹溞（Moina micrura）的捕食效率。实验结果表明,在17℃和21℃时透明薄皮溞对短尾秀体溞的捕食率系数（predation rate coefficient）或称滤过率（clearance rate）分别为15.9和18.2mL predator^-1day^-1。17℃时透明薄皮溞对微型裸腹溞的捕食率系数为30.1mL predator^-1day^-1。不同的猎物密度对捕食率系数亦有影响。在17℃,当猎物密度从200ind mL^-1增为800ind mL^-1时,透明薄皮溞对裸腹溞的捕食率系数则从30.1mL predator^-1day^-1下降为15.1mL predator^-1day^-1,对短尾秀体溞的捕食率系数亦从15.9mL predator^-1day^-1降为7.8mL predator^-1day^-1。;The experiments of predation of Leptodora kindti on two common cladoceras, Diaphanosoma brachyurum and Moina micrura were carried out in Donghu Lake. Predation rate coefficients (Clearance rates) were 15.9 mL predator^-1day^-1 at 17℃,18.2 mL predator^-1day^-1 at 21℃ on Diaphanosoma brachyurum respectively, K-value was increased with temperature. Predation rate coefficient was 30.1 ml predator^-1day^-1 at 17℃ on Moina micrura. K-value of Leptodora kindti on Moina micrura was much higher than that of on Diaphanosoma brachyurum. The experimental volum (density of prey) also affected predation rate coefficients. The bigger the experimental volum,the higher the K-value.Energy flow dynamics of Leptodora kindti in plankton community in Donghu Lake were also studied. Energy of predation of Leptodora kindti on micro-cladoceras was 2.5 J m^-3day^-1 in Donghu Lake.The relationships between predation of Leptodora kindti and population change dynamics of micro-cladoceras were discussed.