胶州湾5种虾虎鱼类的营养和空间生态位

Trophic and spatial niche of five gobiid fishes in Jiaozhou Bay

应用Shannon-Wiener指数和Pianka重叠指数分析了胶州湾5种虾虎鱼类的食物组成、营养生态位宽度、空间生态位宽度及其重叠,通过计算营养空间二维生态位重叠指数探讨了5种虾虎鱼类种间食物竞争与空间分布的关系。结果表明,胶州湾的5种虾虎鱼均属底栖动物食性,其中斑尾刺虾虎鱼（Synechogobius ommaturus）主要以虾类、多毛类和鱼类为食,而六丝钝尾虾虎鱼（Amblychaeturichthys hexanema）、红狼牙虾虎鱼（Odontamblyopus lace-pedii）、纹缟虾虎鱼（Tridentiger trigonocephalus）和钟馗虾虎鱼（Tridentiger barbatus）则主要摄食桡足类、钩虾、涟虫等小型底栖甲壳动物。在5种虾虎鱼中,六丝钝尾虾虎鱼的营养生态位宽度最高（2.65）,纹缟虾虎鱼的空间生态位宽度最高（2.01）,而红狼牙虾虎鱼的营养生态位宽度和空间生态位宽度均最低（分别为1.26和0.97）。5种虾虎鱼之间的营养生态位重叠指数在0.03~0.64之间,其中六丝钝尾虾虎鱼与钟馗虾虎鱼的营养生态位重叠指数最高（0.64）;空间生态位重叠指数在0.08~0.91之间,最高值出现在红狼牙虾虎鱼与钟馗虾虎鱼之间（0.91）;营养空间二维生态位重叠指数在0.0032~0.3648之间,其中钟馗虾虎鱼与六丝钝尾虾虎鱼的营养空间二维生态位重叠指数最高（0.3648）,因此最有可能出现激烈的食物竞争,其他鱼种之间则通过营养或空间生态位的分化而降低了种间竞争的程度。

The food composition,spatial and trophic niche width,trophic-spatial niche overlap for five gobiid fishes in Jiaozhou Bay were studied using the Shannon-Wiener index and Pianka overlap index.The trophicspatial niche overlap was calculated to describe the relationship between feeding competition and spatial distribution of these gobiid fishes.Results showed that all the five gobiid fishes could be classified as benthic carnivorous predators.Synechogobius ommaturus fed mainly upon shrimps,polychaetes and fish.The main prey items of Amblychaeturichthys hexanema,Odontamblyopus lacepedii,Tridentiger trigonocephalus and Tridentiger barbatus were some small benthic crustaceans such as copepods,amphipods and cumacea.Among the five gobiid fishes,A.hexanema had the highest trophic niche width value（2.65） and T.trigonocephalus had the highest spatial niche width value（2.01）.O.lacepedii had the lowest values of trophic niche width（1.26） and spatial niche width（0.97）.The trophic niche overlap values for five gobiid fishes ranged from 0.03 to 0.64,with A.hexanema and T. barbatus having the highest trophic niche overlap value（0.64）.The spatial niche overlap values were between 0.08 and 0.91,with O.lacepedii and T.barbatus having the highest spatial niche overlap value（0.91）.The trophicspatial niche overlap values ranged from 0.003 2 to 0.364 8,with A.hexanema and T.barbatus having the highest trophic–spatial niche overlap value（0.3648）,which may result in intensive food competition.The competitions among other gobiid fishes were reduced by partitioning of trophic and spatial niches.