三门湾海域主要底上动物生态位及种间联结性*

为探究三门湾海域物种间的资源利用情况及生态关系，在该海域进行了底拖网生物调查。根据2017年和2018年夏季在浙江省三门湾海域进行的大型底上生物研究结果，运用优势度(Y)、生态位宽度、生态位重叠、方差比率法(VR)、检验、联结系数(AC)、共同出现百分率(PC)对生态位和种间联结性进行了研究。结果表明:2017~2018年间三门湾海域共捕获大型底上动物53种，包括两年共有种，即主要底上动物22种。其中优势种3种，包括哈氏仿对虾(Mierspenaeopsis hardwickii)、中华栉孔虾虎鱼(Ctenotrypauchen chinensis) 和棒锥螺(Turritella terebra)，这三个物种属中生态位种；三门湾主要底上动物依据生态位宽度值划分为3组，即广生态位种、中生态位种和窄生态位种；种对间生态位重叠值总体差异性较大，其与种对的食性、栖息环境密切相关；根据总体联结性分析得主要底上动物总体呈显著正关联，群落结构较为稳定; 检验、联结系数(AC)和共同出现百分率(PC)表明种对间联结性较弱，趋近于相互独立。三门湾大型底上动物的群落结构比较稳定，但种对间的关联性在逐渐下降。

Niche and interspecies association of major epifauna in Sanmen Bay

In order to explore the resource utilization and ecological relationship of epifauna in Sanmen Bay, the bottom trawl was carried out to collect the epifauna in this area. According to the investigation results in 2017 and 2018 in Sanmen Bay, Zhejiang Province, dominance (Y), niche breadth, niche overlap, the variance ratio method (VR), chi-square test, association coefficient (AC), percentage of co-occurrence (PC) were adopted to study the role of ecological position and interpolation. The results showed that a total of 53 epifaunal species were collected in the Sanmen Bay during 2017-2018, and 22 epifauna were determined as major species because they were collected in both sampling years. Among the major species, 3 dominant species were identified, including Mierspenaeopsis hardwickii, Ctenotrypauchen chinensis and Turritella terebra, which were moderate niche breadth; all epifaunal species were divided into 3 groups, wide niche breadth species, moderate niche breadth and narrow niche breadth species; The overall difference between the coupling pair niche overlap values was significant, closely related to food and habitat; according to the overall coupling analyses, the major epifauna was generally positively related, and the community structure was relatively stable; chi-square test, association coefficient (AC) and percentage of co-occurrence (PC) showed there was weak interspecific associations, independent to each other. The community structure of Sanmen bay was relatively stable, but the association between coupling pairs showed slow decrease.