为揭示七星列岛省级海洋特别保护区鱼类群落现状, 于2014年秋季(11月)和2015年春季(5月)进行底拖网调查。利用生态位测度、非度量多维标度排序和等级聚类等方法对该海域鱼类功能群组成及生态位特征进行了研究。结果表明, 该区鱼类可划分为浮游生物食性、底栖动物食性、游泳动物食性、浮游生物/底栖动物食性、底栖动物/游泳动物食性和杂食性6个功能群。浮游生物食性、底栖动物食性和底栖动物/游泳动物食性功能群是秋季优势功能群, 浮游生物食性、游泳动物食性和杂食性是春季优势功能群。秋季, 主要鱼类生态位宽度值变化范围为0.28-3.84, 其中龙头鱼(Harpodon nehereus)、六指马鲅(Polydactylus sexfilis)、赤鼻棱鳀(Thrissa kammalensis)、红狼牙鰕虎鱼(Odontamblyopus rubicundus)、海鳗(Muraenesox cinereus)、尖头黄鳍牙鱼或(Chrysochir aureus)和叫姑鱼(Johnius belengerii)的生态位宽度值较高; 春季生态位宽度值变化范围为0.36-3.16, 其中带鱼(Trichiurus lepturus)、日本鳀(Engraulis japonicus)、蓝圆鲹(Decapterus maruadsi)、刺鲳(Psenopsis anomala)、龙头鱼和镰鲳(Pampus echinogaster)的生态位宽度值较高。秋季, 主要鱼类生态位重叠值在0-0.94之间波动; 春季, 主要鱼类生态位重叠值在0-0.92之间波动。以丰度数据平方根为基础, 利用非度量多维标度排序和等级聚类分析, 主要鱼类秋季可以分为4组, 而春季可以分为3组。上述结果表明, 保护区鱼类群落的营养结构和空间结构较好。

To understand the status of fish communities in the Qixing Islands Provincial Marine Reserve, China, we carried out bottom trawl surveys during the autumn of 2014 and the spring of 2015. By using niche breadths and their overlaps, non-metric multidimensional scaling and hierarchical cluster dendrograms, we studied the composition of functional groups and niche characteristics of major fish communities. In terms of feeding habits, six functional groups were identified: planktivores, benthivores, piscivores, planktivores/benthivores, benthivores/piscivores and omnivores. Planktivores, benthivores and benthivores/piscivores were the major fish communities in autumn; whereas planktivores, piscivores and omnivores were the dominant fish communities in spring. Shannon-Wiener’s niche breadth index (B_i) and the Pianka’s niche overlap index were used to compare dominant fish species. The niche breadth of dominant fish species ranged from 0.28 and 3.84 in autumn and Harpodon nehereus, Polydactylus sexfilis, Thrissa kammalensis, Odontamblyopus rubicundus, Muraenesox cinereus, Chrysochir aureus and Johnius belengerii had wider niche breadths (B_i>1.0). The niche breadth of dominant fish species ranged from 0.36 and 3.16 in spring and Trichiurus lepturus, Engraulis japonicus, Decapterus maruadsi, Psenopsis anomala, H. nehereus and Pampus argenteus had wider niche breadths (B_i>1.0). The niche overlap of dominant fish species in autumn and spring ranged from 0 to 0.94 and 0 to 0.92, respectively. Based on the square root of the abundance, and using non-metric multidimensional scaling and cluster analysis, fish communities during autumn and spring were divided into four and three groups, respectively. Through the analysis of functional group composition, niche breadth and niche overlap in the Qixing Islands Provincial Marine Reserve, we find improved fish community nutrition structure and spatial structure within the reserve.