兴化湾和闽江口海域春夏季鱼类区系特征

Comparison of fish fauna of two different waters(Minjiang Estuary and Xinghua Bay) of the East China Sea during spring and summer

为反映我国亚热带河口和海湾鱼类区系特点,作者于2008年春季(4月)和夏季(9月)在闽江口和兴化湾海域,采用单拖网进行鱼类学调查,并分析了两个海域鱼类种类组成和生态适应性等,进一步运用Ochilai相似性系数分析两个海域鱼类种类相似性。结果表明,在兴化湾共捕获鱼类108种,其中春季出现48种,夏季出现81种。春季竹筴鱼(Trachurus japonicus)是关键种,矛尾虾虎鱼(Chaeturichthys stigmatias)等是常见种;夏季六指马鲅(Polynemus sextarius)是关键种,赤魟(Dasyatis akajei)等是常见种。闽江口共捕获鱼类77种,其中春季出现36种,夏季出现57种。春季,凤鲚(Coilia mystus)和龙头鱼(Harpodon nehereus)是优势种,赤鼻棱鳀(Thryssa kammalensis)等是常见种;夏季凤鲚是优势种,横纹东方鲀(Takifugu oblongus)等是常见种。温度适应上,兴化湾和闽江口鱼类均以暖水种为主,分别占总种数的76.62%和75.00%,其余是暖温种;在盐度适应方面,则是沿岸种和近海种居多,分别占总种数的91.67%和87.01%。闽江口的河口种多于兴化湾。两个海域鱼类种类组成的相似度较高,而各自水体不同季节之间的相似度较低。由此推测,季节变化是导致兴化湾或闽江口鱼类种类组成变化的主要因素,盐度差异是次要因素。

Based on the data from four oceanographic censuses taken by trawlboat in the Minjiang Estuary and Xinghua Bay in April（spring） and September（summer） of 2008,the species composition,similarity（Ochilai coefficient） and ecological adaptation of fish assembles in these areas were studied.The results in-dicated that in Xinghua Bay,a total of 108 species of fish was identified,among which 48 species occurred in spring and 81 species in summer respectively.Trachurus japonicus was one of the keystone species in spring of Xinghua Bay,The other species,including Chaeturichthys stigmatias were common species.In summer,Polynemus sextarius became keystone species and the other species,including Dasyatis akajei,were com-mon ones.In the Minjiang Estuary,77 species were identified,among which 36 species occurred in spring and 57 species in summer.Both Coilia mystus and Harpodon nehereus were dominant species during spring.In the studied areas,species number of warm water species was highest of all,the proportions of which were as high as 76.62% in total number of species in the Minjiang Estuary and 75.00% in Xinghua Bay.In view of salinity adaptation,the coastal species and the nearshore species were most diversified,with a proportion of 91.67% in total species number of the Xinghua Bay and 87.01% of the Minjiang Estuary.And there were more estuarine species in the Minjiang Estuary comparing with Xinghua Bay.The similarity values between the species compositions of the two waters were higher than the similarities between different seasons re-spectively in each area.Thus,in studied areas,the species variations of the fishes were mainly determined by seasonal change,while the salinity variation was a minor one.