Respiration rates of tropical Atlantic copepods from the Cape Verde Islands

Copepods were sampled at two sampling sites off the island of São Vicente, Cape Verde Archipelago, in spring (March/April) and early summer (May/June) of 2010. The two sampling sites were located in Mindelo Bay (16.90N, 25.01W; bottom depth 22 m) and around 8 km off the town of São Pedro (16.77N, 25.12W; bottom depth 800 m). Samples were collected on board the local fishing vessel 'Sinagoga' using a WP-2 net (Hydrobios, 0.26 m**2 mouth opening, 200 µm mesh size). The net was either applied as a driftnet, drifting for 10 min in 22 to 0 m depth below the surface, or it was towed vertically with a towing speed of 0.5 m/s**1. For stratified sampling, the net was deployed in repetitive hauls from 560 to 210 m, from 210 to 80 m, and from 80 to 0 m in March/April and from 600 to 300 m, 300 to 100 m, and 100 to 0 m in May/June. Additional depth-integrated hauls were conducted from 600-0 m or 500-0 m during both field campaigns. Respiration rates of epi- and mesopelagic calanoid copepods were measured in the land-based laboratory at the Instituto Nacional de Desenvolvimento das Pescas (INDP) in Mindelo. Oxygen consumption was measured non-invasively by optode respirometry at three different ambient temperatures (13, 18, and 23°C) with a 10-channel oxygen respirometer (Oxy-10 Mini, PreSens Precision Sensing GmbH, Regensburg, Germany). All experiments were run in darkness in temperature-controlled incubators (LMS Cooled Incubator Series 1A, Model 280) equipped with water baths to ensure constant temperatures throughout the experiments, tolerating a variation of ±1°C.2010年春季（3月/4月）与初夏（5月/6月），研究团队在佛得角群岛圣维森特岛附近的两个采样位点采集桡足类（Copepods）样本。两个采样位点分别位于明德卢湾（16.90°N，25.01°W；海底水深22米）以及圣佩德罗镇外约8公里海域（16.77°N，25.12°W；海底水深800米）。样本由当地渔船'Sinagoga'号搭载WP-2型浮游生物网（Hydrobios公司生产，网口截面积0.26㎡，网目孔径200μm）采集。该网具可作为漂流网使用，在表层下22至0米水深漂流10分钟；亦可采用垂直拖曳方式，拖曳速度为0.5 m/s。分层采样时，2010年3-4月的网具投放水层依次为560~210米、210~80米及80~0米；5-6月则调整为600~300米、300~100米及100~0米。两次野外调查均额外开展了深度整合拖网采样，采样水层分别为600~0米与500~0米。在明德卢的国家渔业发展研究所（Instituto Nacional de Desenvolvimento das Pescas，缩写INDP）陆上实验室中，研究人员测定了上层浮游带与中层浮游带哲水蚤目（Calanoid）桡足类的呼吸速率。耗氧速率采用无创光学传感器呼吸测定法，使用德国雷根斯堡PreSens Precision Sensing GmbH公司生产的10通道氧气呼吸仪（Oxy-10 Mini），在13℃、18℃及23℃三种环境温度下完成测定。所有实验均在配备恒温水浴的控温培养箱（LMS Cooled Incubator Series 1A，型号280）中于黑暗环境下开展，实验期间温度波动控制在±1℃以内。