温州南部沿岸海域主要鱼类的生态位及种间联结性

国内对生态位和种间关联性的研究主要集中于植物、鸟类和游泳动物群落等方面,而针对鱼类生态位和种间关联性研究鲜有报道.本文基于2015年春季(5月)和秋季(9月)温州南部沿岸海域渔业资源调查与渔获物分析,运用生态位测定、方差比率(VR)、χ²检验、联结系数(AC)、种对共同出现百分率(PC)和点相关系数(Ф)等方法对主要鱼类间的关系进行研究.结果表明: 该海域共鉴定出鱼类47种,隶属于9目27科41属,其中优势种4种,重要种9种,共占17%.通过生态位宽度聚类分析,按生态位宽度将主要鱼类划分为2类:第1类广生态位种包括龙头鱼、棘头梅童鱼、日本鳀、镰鲳、白姑鱼、六指马鲅、蓝圆鲹和带鱼;第2类狭生态位种包括海鳗、六丝矛尾鰕虎鱼、宽体舌鳎、小黄鱼和鳓.主要鱼类间的生态位重叠值为0～0.90,表明物种对资源利用的相似程度存在差异.生态位宽度较窄的宽体舌鳎和海鳗,其重叠值相对较高,说明两个物种间存在一定的竞争.利用VR分析得出主要鱼类间的关联性呈显著正相关.鉴于Ф值能降低χ²检验、联结系数(AC)、种对共同出现百分率(PC)对联结性分析的影响,故采用Ф值测定,得出63个种对为正联结,种间联结性和生态位两者分别与群落结构稳定和群落更替具有不同程度的相关性.

Niche and interspecific association of the dominant fish in the south coastal waters of Wenzhou,China

The studies about the niche and interspecific association in China were mainly focused on the plants, birds and marine animals, and seldom on fish. Based on the fishery resources survey in spring (May) and autumn (September) in 2015, the associations among major fish species in south coastal waters of Wenzhou were investigated. The methods including niche breadth, niche overlap, variance ratio (VR), χ²-test, association coefficient (AC), percentage of co-occurrence (PC) and point correlation coefficients (Ф) were used. The results showed that 47 fish species were identified, including 9 orders, 27 families and 41 genera. Four species were dominant species and 9 were important species, which together accounted for 17%. The niche breadth cluster analysis demonstrated two clearly identifiable ecological niches. The first one referred to wide niche that included Harpodon nehereus, Collichthys lucidus, Engraulis japonicas, Pampus echinogaster, Argyrosomus argentatus, Polynemus sextarius, Decapterus maruadsi and Trichiurus haumela, and the second one was narrow niche that included Muraenesox cinereus, Amblychaeturichthys hexanema, Cunoglossus robustus, Pseudosciaena polyactis and Ilisha elongate. The niche overlap value of the main fish was 0-0.90, indicating that there was difference in the resource utilization among the species. The ecological niche widths of C. robustus and M. cinereus were narrow, and the overlap values were high. This indicated that there was competition between these two species. The VR analysis revealed significant positive correlation among the main fish species. In view of the advantages of Ф value, which could reduce the impact of the analysis results of χ²-test, AC and PC to the interspecific association, the Ф value method was selected in this study, and the association of 63 couples were positive. Both the interspecific association and ecological niche had different degrees of correlation with the stability of community structure and community succession.