Amphipods in sediment traps of the eastern Fram Strait

Life-cycle characteristics of the free-swimming lysianassoid amphipod Cyclocaris guilelmi were investigated and compared to those of other regularly appearing amphipods in the Arctic deep-sea community. In this context we analysed time-series data of meso- and bathypelagic amphipods collected as swimmers in moored sediment traps from 2004 to 2008 at the deep-sea long-term observatory HAUSGARTEN (79°N/4°E) in the eastern Fram Strait, Arctic Ocean. Six mesopelagic and three bathypelagic deep-sea amphipod species regularly occurred in the traps. The lysianassoid C. guilelmi showed a stable interannual population size and seasonal peaks in its occurrence from August to February during the five-year sampling period. The investigation of its population structure and reproduction ecology indicated year-round breeding behavior of this species. Up to 4 cohorts consisting mainly of juvenile and female C. guilelmi were observed. We conclude that C. guilelmi plays an important role within the Arctic amphipod deep water community.本研究对自由游泳的丽沙钩虾科端足类（lysianassoid amphipod）物种Cyclocaris guilelmi的生命周期特征展开调查，并与北极深海群落中其他常见端足类的相关特征进行对比。为此，我们分析了2004年至2008年间，在北冰洋东部弗拉姆海峡的长期深海观测站HAUSGARTEN（79°N/4°E），通过锚定沉积物捕集器采集的、以游泳生物形式捕获的中层带与深渊带端足类的时序数据。该捕集器中常规出现6种中层带深海端足类与3种深渊带深海端足类。丽沙钩虾科端足类Cyclocaris guilelmi在五年采样期内展现出稳定的种群年际规模，其出现频次于每年8月至次年2月出现季节性峰值。对其种群结构与繁殖生态学的研究表明，该物种具备全年繁殖的行为特征。研究共观测到至多4个同生群，其组成以幼年个体与雌性C. guilelmi为主。综上，C. guilelmi在北极深海端足类群落中发挥着重要作用。