中国多金属结核开辟区仔稚鱼的分布特征

Distribution of larval and juvenile fishes in the COMRA's Pioneer Area

利用 1 997年～ 1 999年“大洋一号”调查船在中国多金属结核开辟区用邦哥网所采集的样品 ,对仔稚鱼的种类组成、密度的平面分布和年间变化及其与环境因子的关系进行了研究。结果表明 :中国开辟区共有 2 2科 6 1种仔稚鱼 ,其中大洋性发光鱼类灯笼鱼科的种类最多 ,达1 7种 ,约占总种类数的 2 8% ,其次是钻光鱼科 (6种 )、金枪鱼科 (6种 )和拟白鲑科 (5种 ) ,分别约占总种类数的 1 0 %、 1 0 %和 8%。东、西两区的种类组成有较大的差异 ,共有种仅为 1 7种 ,东区种类数 (48种 )明显多于西区种类数 (3 0种 )。仔稚鱼的密度有明显的空间和时间变化 ,东区仔稚鱼的密度高于西区 ,东区 1 999年仔稚鱼的密度约为 1 997年的 5倍 ,西区 1 999年仔稚鱼的密度约为 1 998年的 3倍。仔稚鱼密度的年间变化可能与 El

On the basis of the materials obtained from 0~50m Bongo net in the COMRA's Pioneer Area during summer (July^August)cruise in 1997~1999, species composition, horizontal distribution and interannual variation of the density of fish larva and its relations to environmental factors are discussed in this paper. Results show that there are 22 families and 61 species of fish larvae in the surveyed area, and 17 species, 6 species, 6 species and 5 species belong to Myctophidae, Gonostomatidae, Thunnidae and Paralepididae respectively. Species composition between eastern surveyed area and western surveyed area is obviously different. There are only 17 species that jointly occur in the two areas. The species number of fish larva in the eastern area is obviouly more than that in the western area. The total density of fish larvae shows obvious spatial and interannual variations. It was higher in the eastern area than in the western area and significantly higher in 1999 than in 1997 and in 1998. The interannual variations of fish larval density probably relate to the 1997~1998 El Nio event.