防城港湾海域甲壳类群落结构及其与环境因子的关系

Crustacean community structure and its relationship with environmental factors of Fangchenggang Bay,Guangxi,China

2016年5、8、11月和2017年2月对防城港湾海域开展渔业资源和环境调查,研究了河口湾甲壳类群落结构的空间和季节变化,并分析了甲壳类群落结构与主要环境因子的关系。结果表明:全年调查共捕获甲壳类60种,隶属于2目19科35属,暖水性种和暖温性种分别占60.0%和40.0%。春季有51种,夏季有34种,秋季有35种,冬季有26种,秋、冬季间种类相似性指数最高。周年优势种有亨氏仿对虾(Parapenaeopsis hungerfordi)、钝齿蟳(Charybdis hellerii)、日本囊对虾(Marsupenaeus japonicus)、刀额新对虾(Metapenaeus ensis)和近缘新对虾(Metapenaeus affinis)等5种,主要种有须赤虾(Metapenaeopsis barbata)、长毛明对虾(Fenneropenaeus penicillatus)、中型新对虾(Metapenaeus intermedius)、口虾蛄(Oratosquilla oratoria)、周氏新对虾(Metapenaeus joyneri)和远海梭子蟹(Portunus pelagicus)等6种。4个季度最大优势种分别为亨氏仿对虾(春季)、刀额新对虾(夏季)、近缘新对虾(秋季)、钝齿蟳(冬季)。全湾甲壳类年均密度和生物量分别为32201尾/km^2和212.29 kg/km^2,均呈现明显的季节变化和空间差异。甲壳类各站位种数变化范围为2~17种,种类多样性指数(H′)在0.200~3.160之间,丰富度指数(d)在0.200~2.230之间,均匀度指数(J)在0.160~0.988之间;种数、H′、d和J表现出显著性空间差异,种数和J表现出显著性季节变化。聚类分析、相似性分析及相似性百分比分析表明该海域甲壳类群落存在一定程度的时空异质性。生物-环境分析表明影响该海域甲壳类群落结构的环境因子存在季节差异。

Fishery stock surveys were carried out in May,August and November 2016 and February 2017,and spatiotemporal dynamic of the crustacean community structure and its relationship with the environmental factors of the Fangchenggang Bay were analyzed.A total of 60 crustacean species in 2 orders,19 families and 35 genera were collected,among which the warm-water species and warm-temperate species accounted for 60.0%and 40.0%,respectively.The species numbers recorded were 51 in spring,34 in summer,35 in autumn and 26 in winter.The similarity index was the highest in autumn and winter.The dominant species defined by the index of relative importance(IRI)higher than 500 were composed of Parapenaeopsis hungerfordi,Charybdis hellerii,Marsupenaeus japonicus,Metapenaeus ensis and Metapenaeus affinis,and the main species with IRIs ranging from 100 to 500 were Metapenaeopsis barbata,Fenneropenaeus penicillatus,M.intermedius,Oratosquilla oratoria,M.joyneri and Portunus pelagicus.The most dominant species is P.hungerfordi in spring,M.ensis in summer,M.affinis in autumn and C.hellerii in winter.The annual average density and biomass in the bay were 32201 ind./km^2 and 212.29 kg/km^2,respectively.Seasonal and spatial variations of density and biomass were significant.Species number(SN)ranged from 2 to 17 with species diversity index(H′)from 0.200 to 3.160,richness index(d)from 0.200 to 2.230 and evenness index(J)from 0.160 to 0.988.Spacious variations were significant for SN,H′,d and J,but seasonal variations,only for SN and J.The analysis of clustering,similarity(ANOSIM)and similarity of percentage(SIMPER)showed that spatiotemporal heterogeneity existed in the community structures to some extent.Biota and environment matching(BIOENV)showed that the major environmental factors determined the seasonal distribution patterns of the crustacean communities in the bay.