Sampling information on lysianassoid amphipod crustaceans from the expedition PS82 (ANT-XXIX/9) to the Filchner area, Weddell Sea, Antarctica in 2013/2014

An integrative inventory, combining morphological identifications with DNA barcoding, of the amphipod scavenging fauna (Lysianassoidea) of the Filchner area in the south-eastern Weddell Sea is provided here. This understudied area, neighbouring the Filchner-Ronne Ice Shelf, represents a key oceanographic region for the global circulation but is, however, likely to be impacted by a myriad of consequences of warming waters. It also represents a biological hotspot and therefore, this area has been recently included as a candidate for a Marine Protected Area in the Southern Ocean (Weddell Sea MPA). Over 4400 lysianassoids were investigated for species richness and abundances at 20 different stations using different sampling devices, including the southernmost baited traps deployed so far (76°S). A high species richness was observed: 29 morphospecies of which five were new to science. Molecular species delimitation methods indicated the presence of 42 lineages; for four species, several (cryptic) lineages were found. More than 96% of the lysianassoids collected with a baited trap belonged to the species Orchomenella pinguides s.l. The diversity of the amphipod scavenger guild in this ice-bound ecosystem of the Weddell Sea is discussed in the light of bottom-up selective forces. Harbouring spawning and nursery grounds for silverfish and icefishes, which are preyed upon by seal species, abundant fish and mammalian food falls are likely to represent the major food for scavengers in this southernmost part of the Weddell Sea. Finally, the importance of such biodiversity surveys to better understand the ecological role of scavengers in this system is highlighted.本研究构建了整合形态鉴定与DNA条形码（DNA barcoding）技术的威德尔海东南部菲尔希纳区域腐食端足类（Lysianassoidea）动物群名录。该研究不足的区域毗邻菲尔希纳-龙尼冰架，既是全球环流关键海洋学区域，也极易受到海水变暖引发的一系列连锁影响的冲击。同时该区域亦是生物多样性热点区域，因此近期已被纳入南大洋海洋保护区（Marine Protected Area，MPA）候选名录。研究团队采用多种采样装置，在20个不同采样站位对超过4400只食腐钩虾超科类群开展物种丰富度与种群丰度调查，其中部署了迄今纬度最高的投饵诱捕陷阱（南纬76°S）。调查显示该区域物种丰富度极高：共记录29个形态种，其中5个为科学新种。分子物种界定方法则揭示了42个物种支系的存在，其中4个物种各含多个隐存支系。通过投饵诱捕陷阱采集到的食腐钩虾超科类群中，超过96%隶属于平突钩虾属广义种（Orchomenella pinguides s.l.）。本研究基于上行选择压力（bottom-up selective forces）的视角，探讨了威德尔海该冰封生态系统中腐食端足类功能群的多样性特征。该区域作为银鱼与冰鱼的产卵场及育幼场，而这些鱼类又是海豹的捕食对象；丰富的鱼类及海洋哺乳动物尸体沉降物，极有可能是威德尔海南部区域腐食动物的主要食物来源。最后，本研究强调了此类生物多样性调查对于深入理解该生态系统中腐食动物的生态位功能的重要意义。