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涟虫类端足类（lysianassoid amphipod）Cyclocaris guilelmi的生活史特征展开调查，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。于此研究框架内，我们分析了2004至2008年，于北冰洋东部弗拉姆海峡（Fram Strait）的深海长期观测站HAUSGARTEN（79°N/4°E），通过锚定沉积物捕获器（moored sediment traps）采集的、作为自由游泳个体的中层带（mesopelagic）与深远洋带（bathypelagic）端足类的时间序列数据。该锚定沉积物捕获器中常规捕获到6种中层带端足类与3种深远洋带端足类。涟虫类端足类Cyclocaris guilelmi的种群规模年际间保持稳定，且在五年采样期内，其出现量的季节峰值均集中于8月至次年2月。对该物种种群结构与繁殖生态学的调查表明，其具备全年繁殖的行为特征。本次研究共观测到最多4个种群群组，其组成主体为幼年个体与雌性Cyclocaris guilelmi。综上，我们认为Cyclocaris guilelmi在北极深海端足类群落中扮演着重要角色。