Fig. 1.

Sampling of individual copepods from the North Atlantic. a Individual copepods were collected over two sampling dates at Tröllet Station within Trondheimsfjord, Norway (189 individuals in total; C. finmarchicus C5 copepodids). To capture individuals in a wide range of physiological states, copepods were collected from surface (0–50 m depths) and deep (250–350 m depths) seawater. At the surface, copepods were largely in an active state, while at depth, copepods were often in diapause (dormant). Among copepod individuals, physiological differences were manifested by changes in morphology, including differences in b prosome (body) volume, c oil sac fractional fullness, d the presence of food in the gut, e and overall bacterial load. Procedures for quantifying each of these characteristics are described in Materials and methods. In all plots, black bars indicate mean value