黄海中部近岸春夏季鱼卵、仔稚鱼群落结构特征

2013年4月下旬至7月上旬,采用浅水I型网垂直拖网的调查方式对黄海中部20m以浅海域(34°30'—35°30'N,119°20'—120°20'E)的鱼卵、仔稚鱼种类组成与数量分布进行了6个航次的综合调查。春夏季共采集鱼卵21种(未定种3种),共计2247粒,隶属于9科15属。仔稚鱼22种(未定种1种),共计286尾,隶属于13科17属。鱼卵优势种为日本鳀Engraulis japonicus、赤鼻棱鳀Thryssa kammalensis、江口小公鱼Stolephorus commersonnii、皮氏叫姑鱼Johnius belengerii和属Callionymus spp.。仔稚鱼优势种为大银鱼Protosalanx chinensis、白姑鱼Argyrosomus argentatus、日本鳀、赤鼻棱鳀和皮氏叫姑鱼。鱼卵丰度和分布与经度呈负相关、与SST呈正相关,但与其他环境因子如纬度、表层盐度(SSS)和水深等无显著相关性。仔稚鱼丰度和分布与上述环境因子均未表现出显著相关性。基于Bray-Curtis指数的聚类分析表明,鱼卵优势种包括集中分布于研究水域34°48'N以南海域(江口小公鱼、皮氏叫姑鱼和青鳞小沙丁Sardinella zunasi)、10m等深线以内(赤鼻棱鳀),以及北部水域(日本鳀和属)3种主要聚集类型;仔稚鱼优势种包括集中分布于34°48'N—35°12'N海域(赤鼻棱鳀和日本鳀)、连云港外海浅水区(白姑鱼、皮氏叫姑鱼和梭鱼Liza haematocheilus,以及南部水域(褐菖鲉Sebastiscus marmoratus和鲬Platycephalus indicus)3种主要聚集类型。研究结果揭示了黄海中部近岸海域鱼卵、仔稚鱼群落的时空分布格局动态,为科学认识环境变动下该海区渔业种群数量动态和资源变化提供了科学依据。

The community structure of ichthyoplankton in the central Yellow Sea in spring and summer

Knowledge of the ecology of ichthyoplankton (eggs, larvae, and fry) is important for understanding the spawning ecology and the population dynamics of fishery species. In this study, a total of six fishery research cruises were conducted to investigate the community structure and ecology of ichthyoplankton in the central Yellow Sea (34°30''-35°30'' N, 119°20''-120°20'' E), one of the most concentrated spawning areas for fishery species in Chinese coastal waters, from late April to early July 2013. To collect ichthyoplankton, zooplankton nets (mouth diameter=50 cm, length=145 cm, and mesh size=0.505 mm) were vertically trawled in waters below the 20 m isobath line. The species composition, abundance, and distribution of the ichthyoplankton, and their relationships with environmental factors, were studied. A total of 2247 eggs and 286 larvae were collected during the research cruises. The eggs were identified as belonging to 18 species in 15 genera in 9 families; 3 species could not be identified. The eggs were dominated by Engraulis japonicus, Thryssa kammalensis, Stolephorus commersonii, Johnius belengerii, and Callionymus spp. The larvae were identified as belonging to 21 species in 17 genera in 13 families; only one species could not be identified. The dominant larval species included Protosalanx hyalocranius, Argyrosomus argentatus, E. japonicus, T. kammalensis, and J. belengerii. The abundance of the eggs was positively correlated with the sea surface temperature (SST) but was negatively correlated with the longitude (P < 0.05). In contrast, the abundance of the larvae did not show a significant correlation with any of the investigated environmental factors, such as longitude, latitude, SST, sea surface salinity (SSS), or water depth. Cluster analysis based on the Bray-Curtis similarity index identified three assemblages of eggs and larvae at the 35% and 12% similarity levels, respectively. The eggs were grouped into assemblages dominating the southern waters from 34°48''N (S. commersonii, J. belengerii, and Sardinella zunasi), the < 10 m isobath waters (T. kammalensis), and the northern waters (E. japonicas and Callionymus spp.). The larvae were grouped into assemblages that were mainly distributed in the 34°48''N-35°12''N waters (T. kammalensis and E. japonicus), the shallow waters off Lianyungang (A. argentatus, J. belengerii, and Liza haematocheilus), and the southern part of the study area (Sebastiscus marmoratus and Platycephalus indicus). The findings of this study clarified the spatial and temporal distribution patterns as well as the structure of the ichthyoplankton community in the central Yellow Sea, which may help to improve our understanding of the population dynamics of fishery species in these waters.