长江口鱼卵仔鱼资源现状的调查与分析

The ichthyoplankton resource investigation in Changjiang Estuary

根据2003年5月至2004年11月长江口海域7个航次、115个站次的鱼卵仔鱼调查采样资料分析,共鉴定出该海域的鱼卵仔鱼51种,隶属10目27科45属;其中,5种仅鉴定到科,4种仅鉴定到属,还有两种未能鉴定。在长江口门附近鱼卵较为集中,绝大部分为凤鲚鱼卵,占鱼卵总数的95.7%,其它小部分分别为鮻、斑点马鲛、长蛇鲻、中华小公鱼、小带鱼以及鲆科的鱼卵。中华小公鱼的仔鱼出现次数最多,占仔鱼总次数的38.4%;凤鲚、虎鱼科、棘头梅童鱼、鮻和斑鱼祭的仔鱼分别占仔鱼总次数的19.7%、14.4%、6.6%、6.2%和3.5%。长江口门内分布的主要仔鱼种类为凤鲚、赤鼻棱鱼是、中华小公鱼等;长江口门以外分布的主要仔鱼种类为凤鲚、鮻、鲆科、小黄鱼和长蛇鲻等;其中凤鲚、中华小公鱼等的仔鱼和鱼卵较多。5月鱼卵仔鱼的种类和数量较多,2月和11月的较少。与历史同期相比,该海域部分种仔鱼类已经消失,棘头梅童鱼等经济种类的鱼卵仔鱼资源补充量急剧下降,表明长江口海域经济种类仔鱼资源已受到衰竭的威胁。

According to 7 ichthyoplankton resource investigation in Changjiang Estuary during May 2003 to November 2004, there are 51 ichthyoplankton identified to species belonging to 10 Order 26 Family 44 Genus; otherwise there are 4 species identified to Family, 3 species identified to genus and 2 species unidentified. The fish egg mainly distributed nearby sea entry, most of which is Coilia rnystus occupying 95.7 % of total, other species include Liza haernatocheila, Scomberomorus guttatus, Saurida elongate, Stolephorus chinensis, Eupleurograrnmus rnuticus; the dominance of fish larvae was Stolephorus chinensis occupying 38.4% of total, other important species include Coilia mystus （19.7%）, GOBIIDAE （ 14.4 % ）, Collichthys lucidus （6.6 % ）, Konosirus punctatus （6. 2 % ） and Konosirus punctatus （3.5%）. The species of ichthyoplankton is more abundant in May and relatively less in February and November. Compared with historical data, some species disappeared, the abundance of some economically important species such as Collichthys lucidus decreased dramatically, which indicated that the compensatory resources of economical fish are being threatened.