长江口渔场鱼类组成和多样性

利用2000年在长江口渔场4个季节的调查资料,对该渔场的鱼类组成和多样性进行了研究。结果表明:共捕获鱼类73种,隶属于11目,40科,62属。季度出现频数F=1~4的鱼类种数分别为38、9、12、14种。所有出现种类的适温性以暖温性和暖水性基本相当,在所出现的海洋性种类、河口性(低盐性)种类、河海洄游性种类三种生态类型中,以海洋性种类占绝对优势,河海洄游性种类相对较少。根据优势度曲线可以看出夏季优势种最突出,秋季优势种最不明显。通过相似性指数的分析表明,季节间的相似性以春季和冬季较为相似,夏季和秋季差异较大。各个季节的多样性指数D、H'、J以春季和冬季较接近,夏季和秋季相差较大,并且四个季节中以秋季较高。在4个季节的调查中,各站鱼类多样性指数相差较大,可能是因为出现频率小且数量少的偶见种相对较多

The composition and diversity of fishes on fishing grounds of Changjiang estuary

Based on seasonal investigations in 2000,the paper deals with the composition and diversity of fishes on the fishing grounds of Changjiang estuary.There were 73 species of fishes in all,which belong to 62 genera in 40 families of 11 orders.The number of species occurring in one to four seasons was 38,9,12,14,respectively.In all species,the number of warm-temperate species was as much as that of warm-water species.Of the three ecological types,oceanic species was absolutely dominant and migratory species was comparatively less than estuarine species.By analysing the similarity index,it was more conformity with the similarity index between spring and winter,but it had great differences between summer and autumn.The indexes of diversity D,H',J were higher in autumn in comparison with other seasons,but more similar between spring and winter and more different between summer and autumn.In the survey of four seasons,the index of diversity has quite differences in each station,it may be caused by occidental species which are less in frequency and in number.