温州瓯江口春、秋季主要游泳动物生态位及其分化

Ecological niche and differentiation of major nekton species in the spring and autumn of Wenzhou Oujiang Estuary

根据2020年秋季(11月)和2021年春季(3月)在温州瓯江口附近海域两次渔业资源调查的数据,利用相对重要性指数(IRI)、生态位宽度(Bi)、生态位重叠(Oik)和冗余分析(RDA)等方法,分析主要游泳动物的生态位及其分化。结果表明:温州瓯江口海域游泳动物物种丰富,春季优势种数目高于秋季,其中秋季口虾蛄(Oratosquilla oratoria)的相对重要性指数最高。两季主要游泳动物的生态位宽度(Bi)变化范围为1.20~7.53,广生态位种(Bi≥6)包括两季的日本蟳(Charybdis japonica)、秋季的棘头梅童鱼(Collichthys lucidus)和三疣梭子蟹(Portunus trituberculatus)和春季的脊尾白虾(Palaemon carinicauda);中生态位种(3<Bi<6)包括秋季的龙头鱼(Harpadon nehereus)、口虾蛄(Oratosquilla oratoria)和春季的花鲈(Lateolabrax japonicus)等;窄生态位种(0<Bi≤3)包括秋季的刀鲚(Coilia nasus)、春季的口虾蛄等。两季的生态位重叠变化范围为0.03~0.96,种对间生态位重叠总体差异性较大,其主要受不同物种的食性、栖息环境及捕食关系影响。RDA主要从环境因子影响物种分布和解释种对间生态位重叠不合理现象两个角度体现生态位分化。

Based on data collected from two fisheries resource surveys in the vicinity of the Oujiang River Estuary in Wenzhou in the autumn of 2020(November)and the spring of 2021(March),the ecological niche and differentiation of major nekton species were analyzed using methods such as the index of relative importance(IRI),ecological niche width(Bi),ecological niche overlap(Oik),and redundancy analysis(RDA).The species richness of nekton species in the Wenzhou Oujiang River estuary was high with a higher number of dominant species in the spring than in the autumn.The index of relative importance of Oratosquilla oratoria was the highest in autumn.The niche width(Bi)of the major nekton species in the two seasons ranged from 1.20 to 7.53.The broad niche width species(Bi≥6)included the Charybdis japonica in both seasons,Collichthys lucidus and Portunus trituberculatus in autumn and Palaemon carinicauda in spring.Medium niche width species(3<Bi<6)included Harpadon nehereus,Oratosquilla oratoria in autumn and Lateolabrax japonicus in spring,etc.Narrow niche width species(0<Bi≤3)included Coilia nasus in autumn and Oratosquilla oratoria in spring,etc.The niche overlap in the two seasons ranged from 0.03 to 0.96,with significant differences in the overlap between species pairs,which were mainly influenced by differences in feeding habits,habitat and predation relationships.RDA mainly reflected the ecological niche differentiation from two perspectives:the impact of environmental factors on species distribution and the explanation of unreasonable ecological niche overlap between species pairs.