fish species composition

基本解释

After 20 century 70s, fish species composition significant changed on the basis of the species composition of fish-scale-deposition.
通过鱼鳞种类组成比例的改变，发现上世纪70年代后，鱼类资源结构发生了显著的变化。
Fish species composition in seven Lakes of the Yunnan Plateau from 1990s to 2004 were compared to investigate variation and reasons for endangered native fishes.
根据七个云南高原湖泊近年渔获物的变化情况，探讨了云南土著鱼类的变化特征和濒危的原因。
According to the data selected from bottom trawl fishery resource monitoring in the East China Sea from 1997 to 2000, the species composition and seasonal variation of small-sized fish were analysed.
根据1997~2000年东海区底拖网渔业资源调查资料，分析和讨论了东海区小型鱼类的种类组成和季节变化。