Community Ecology of Fish Eggs, larvae, and Juveniles in Ago Bay, Mie Prefecture

1993年7月至1995年8月期间，在阿古湾（2个站）和海湾外（1个站）使用三角形水中幼虫网每月收集幼鱼。共捕获鱼卵53739粒，捕获幼鱼幼鱼18710条。前者有9目29科43种（最低分类群），后者有18目69科178种（最低分类群）。对分类资料不足的鱼苗进行了详细描述。在海湾外，卵的数量和类群数量都很丰富。在冬季，海湾里的卵很少。夏、秋两季鱼苗群落种类较多，春、夏两季鱼苗群落数量较多。海湾外的分类群数量丰富。收集到大量的卵囊和前屈幼虫，但屈曲和后屈幼虫和幼鱼在海湾中很少。这一现象表明，在海湾中孵化的一些幼虫可能在生命的早期阶段就外出了。湾外鱼苗群落多样性高于湾内鱼苗。另一方面，多样性在夏季增加，在冬季减少。幼鱼群落按季节划分为夏秋期，以梭鱼科、梭鱼科为代表。6和Rudarius ercodes，以及以Sebastiscus marmoratus为代表的冬春阶段。湾外情况较为复杂，也可分为以日本鳗鲡（Engraulis japonicus）为代表的春夏期、以各种表演类幼虫为代表的夏秋期和以S.marmoratus和s.p p为代表的冬春期。

Monthly larval fish collection using a triangular midwater larval net was operated in Ago Bay (2 stations) and at out of the bay (1 station) during the period from July 1993 to August 1995. A total of 53739 eggs and a total of 18710 fish larvae and juveniles were collected by the net. The former could be classified into 9 orders, 29 families and 43 species (lowest taxon), and the latter 18 orders, 69 families and 178 species. The fish larvae lacking in taxonomical data were described in detail.Eggs were abundant in both number and number of taxa at out of the bay. During the winter season, eggs were very few in the bay.Larval fish community was generally more various in summer and autumn, and more numerous in spring and summer. Number of taxa was plentiful at out of the bay. A lot of yolk-sac and preflection larvae were collected, but the flexion and postflexion larvae and juveniles were very few in the bay. This phenomenon suggested that some larvae hatched in the bay may go out during their early life stages.The larval fish community at out of the bay showed higher diversity than that in the bay. On the other hands, the diversity increased in summer and decreased in winter. The larval fish community in the bay was divided seasonally into summer-autumn phase represented by Callionimidae, Gobiidae gen.sp.6 and Rudarius ercodes, and winter-spring phases represented by Sebastiscus marmoratus. Those at out of the bay being more complicated were also divided into spring-summer phase represented by Engraulis japonicus, summer-autumn phase represented by various perciform larvae, and winter-spring phase represented by S.marmoratus and S.spp.