Site characteristics, diversity indices and species abundance of peracarid crustaceans during Walther Herwig III cruise along the southern shelf of Greenland

Abstract The species composition of peracarids (Crustacea: Malacostraca) of the Greenland shelf between 60°N and 65°N was investigated by means of 10 qualitative epibenthic samples in relation to environmental factors. In total, 59,234 specimens were collected belonging to 219 species. The relative abundance was much higher on the western shelf (total of 41,594 specimens) than on the eastern shelf (total of 17,640 specimens with same effort). Three species were new to science, while five records were new for the investigated area. The species composition was dominated by amphipods (58%), while the relative abundances of isopods (25%), cumaceans (11%) and tanaidaceans (6%) were much lower. Diversity and evenness were similar in the eastern and the western areas. Multivariate analyses of the species relative abundances divided the peracarids into a southeastern and southwestern Greenland fauna. Based on a correlation analysis between faunal data and five environmental variables, the separation between the two areas was mainly based on sediment type. Species contributing most to the separation between eastern and western fauna included the amphipods Hardametopa nas-uta, Photis reinhardi and Phoxocephalus holboelli, the isopods Pleurogonium spinosissimum, Iolella laciniata and Nannoniscus oblongus and the cumaceans Leucon cf. nasicoides and Campylaspis horrida. Species distribution patterns are discussed in the light of habitat and feeding preferences.

摘要 本研究针对北纬60°至65°之间的格陵兰陆架区囊虾类（Peracarida，甲壳纲：软甲纲）的物种组成展开调查，采用10份定性底栖表层采样（epibenthic samples）并结合环境因子开展分析。本研究共采集到59234号标本，隶属于219个物种。西部陆架的相对丰度（总计41594号标本）显著高于东部陆架（同等采样强度下总计17640号标本）。其中3个物种为科学新种，另有5个物种为该研究区域的新分布记录。物种组成以端足目（Amphipoda）占优，相对丰度达58%；等足目（Isopoda，25%）、涟虫目（Cumacea，11%）与塔奈虫目（Tanaidacea，6%）的相对丰度则明显更低。东部与西部区域的物种多样性和均匀度水平相近。对物种相对丰度开展的多元分析将囊虾类划分为格陵兰东南部与西南部两大动物区系。基于动物区系数据与5项环境变量的相关性分析，两大区域的分化主要由沉积物类型主导。对东西部动物区系分化贡献最大的物种包括：端足目的Hardametopa nasuta、Photis reinhardi及Phoxocephalus holboelli；等足目的Pleurogonium spinosissimum、Iolella laciniata及Nannoniscus oblongus；以及涟虫目的Leucon cf. nasicoides和Campylaspis horrida。本研究结合物种栖息环境与摄食偏好，对其分布格局展开了讨论。