中文摘要：

秀体溞（Diaphanosomaspp.）是华南地区水库中枝角类的优势属.于2000年对广东省19座大中型水库丰水期和枯水期2次采样和2001-2006年对飞来峡水库、新丰江水库和大镜山水库分别进行了16、12和7次采样.这19座水库的样品中,5座水库仅有模糊秀体溞（D.dubium）,8座水库仅有奥氏秀体溞（D.orghidani）,2个种在6座水库中同时存在.模糊秀体溞与奥氏秀体溞所占居的生境有明显差异,以模糊秀体溞为优势种的水体主要为富营养化水库,以奥氏秀体溞为优势种的水体则多为贫营养水体.在数量上,丰水期秀体溞的丰度高于枯水期.模糊秀体溞和奥氏秀体溞在形态、食物需求和对鱼类捕食的逃避能力上的差别决定了它们在水库中的分布差异.

英文摘要：

Diaphanosoma is a dominant genus of cladocera in South China, and widely distributes in lakes and reservoirs. To understand its regional population distribution, the animals were sampled in dry and flood seasons in 19 reservoirs of Guangdong Province during 2001 and 2006 monthly or seasonally in three reservoirs of Feilaixia, Xinfengjiang and Dajingshan, which have been under different trophic states. Adult Diaphanosoma was found in all reservoirs, where 5 reservoirs had only D. dubium, 8 reser- voirs had only D. orghidani, and 6 reservoirs had the two species. The two species showed an apparent difference in niches. D. dubium mainly dominated in eutrophic reservoirs, while D. orghidani did in oligotrophic reservoirs. Distributions of D. dubium and D. orghidani in the reservoirs can be well explained by their differences in morphology, food selection and ability of avoiding predators.