小黄鱼育幼期吕泗渔场的饵料浮游动物特征

Distribution pattern of diet zooplanktons in Lsi fishing ground during nursing period of small yellow croaker

根据2008年6月在吕泗渔场(31.90°N-32.10°N、121.70°E-121.95°E)海域生态环境调查资料,分析了该区饵料浮游动物种类分布、优势种、数量分布、多样性等特征。结果表明:该区共出现饵料浮游动物31种(不含浮游幼体和腔肠动物),种类数和丰度均以桡足类占据优势;该区总生物量均值为845.54mg.m-3,其中大潮时为895.58mg.m-3,分布趋势为北部高于南部,小潮时为795.49mg.m-3,分布趋势为中部较高;6月吕泗渔场饵料浮游动物优势种分别是真刺唇角水蚤(Labidocera euchaeta)、中华哲水蚤(Calanus sini-cus)、小拟哲水蚤(Paracalanus parvus)、太平洋纺锤水蚤(Acartia pacifica)、火腿许水蚤(Schmackeria poplesia)、长轴螺(Peraclis reticulata)、长额刺糠虾(Acanthomysis longirostris);大潮时真刺唇角水蚤和中华哲水蚤优势度最高均为0.19,小潮时真刺唇角水蚤优势度最高为0.40;在吕泗渔场,6月饵料浮游动物生物量较高,优势种数较多,反映出该渔场小黄鱼饵料环境的稳定性,为小黄鱼幼体生长提供了良好的饵料条件。

Based on the investigation of oceanographic environment of Lsi fishery （31.90°N-32.10°N,121.70°E-121.95°E） in June 2008,this paper studied the species distribution pattern,dominant species,quantitative distribution,diversity,and other ecological parameters of diet zooplanktons in the fishing ground. A total of 31 diet zooplankton species （excluding planktonic larva and coelenterate） were observed,and planktonic copepods were dominant both in species number and in abundance. The total biomass of the zooplankton was averagely 845.54 mg.m^-3,with 895.58 mg.m^-3 during spring tide and 795.49 mg.m^-3 during neap tide. During spring tide,the biomass was higher in the north than in the south; while during neap tide,the biomass was the highest in the middle of the ground. In June,the dominant species were Labidocera euchaeta,Calanus sinicus,Paracalanus parvus,Acartia pacifica,Schmackeria poplesia,Peraclis reticulata,and Acanthomysis longirostris. During spring tide,both L. euchaeta and C. sinicus had the highest dominance of 0.19; during neap tide,the highest dominance of L. euchaeta was 0.40. In short,the biomass of the diet zooplanktons in Lsi fishing ground was very rich,and the zooplanktoic community was composed of many dominant species,suggesting that the community structure of the diet organisms was stable,being able to provide a fine diet surrounding for the growth of juvenile small yellow croaker.