浙江南部近岸海域春季蟹类群落结构特征

根据2011年春季(4月、5月和6月)对浙江南部近岸海域进行的共3个航次的底拖网调查数据, 分析了该海域蟹类的种类组成、数量分布、优势种和多样性等特征。结果表明, 春季共捕获蟹类13种, 隶属于1目4科7属; 上述所有种类中, 除3种不确定外, 其余分别为广温广盐种4种、高温广盐种4种与高温高盐种2种; 4月与6月蟹类的质量密度与尾数密度间均存在显著差异(P<0.05); 4月与5月、6月间的多样性指数(H′)差异均显著(P<0.05); 丰富度指数(D)与底盐、水深两者均呈线性正相关(P<0.05), 而多样性指数(H′)、均匀度指数(J′)与质量密度均呈线性负相关(P<0.05)。浙江南部近海春季蟹类群落以中小型非经济种类为主, 结构较简单, 其丰富度(D)随底盐、水深的增加而增加, 而多样性(H′)与均匀度(J′)随质量密度的升高而降低。另外, 双斑蟳(Charybdis bimaculata)为春季的绝对优势种, 且其对质量密度与尾数密度的总贡献率均超过50%, 这可作为渔业生态功能区及重要渔业水域选划的依据之一。

Analysis of crab community characteristics in South Zhejiang coastal areas during spring

Based on three bottom trawl surveys carried out in spring (June), 2011, crab species composition, weight density and individual density distribution, dominant species, and community characteristics were analyzed by analysis of variance, linear regression, cluster analysis, and non-metric multidimensional scaling. Thirteen crab species, belonging to 7 families of 4 orders in 1 class were sampled. Of these, four were eurythermal and eurysaline, four were hyperthermal and eurysaline, two were hyperthermal and hysaline, and three species were of uncertain ecotypes. Weight density Aprilas did the number abundance density indices) differed significantly betweenhe Margalef richness index (were negatively correlated (<0.05). During spring in the study area, the non-economic mid-minitype crab species occupied the D increased with increase in sea. In addition, most dominant species density in this can be used as a basis for identifying the ecotype function zone and important fisheries waters.