Dietary plasticity in small Arctic copepods as revealed with prey metabarcoding.

Objectives: Small copepods (<2 mm) compose an important constituent of the Arctic marine food web, but their trophic interactions remain largely unexplored, partly due to methodological limitations.

Methods: We here characterize the prey of the abundant cyclopoid , harpacticoid and calanoid spp. from the Arctic Barents Sea and Nansen Basin during four seasons using brute force prey metabarcoding of the 18S rRNA gene.

Temperature-dependent egg production and egg hatching rates of small egg-carrying and broadcast-spawning copepods , and .

Reproductive rates of copepods are temperature-dependent, but poorly known for small copepods at low temperatures, hindering the predictions of population dynamics and secondary production in high-latitude ecosystems. We investigated egg hatching rates, hatching success and egg production of the small copepods and (sac spawners) and (broadcast spawner) between March and August. Incubations were performed at ecologically relevant temperatures between 1.

Genetics redraws pelagic biogeography of .

Planktonic copepods of the genus play a central role in North Atlantic/Arctic marine food webs. Here, using molecular markers, we redrew the distributional ranges of species inhabiting the North Atlantic and Arctic Oceans and revealed much wider and more broadly overlapping distributions than previously described. The Arctic shelf species, , dominated the zooplankton assemblage of many Norwegian fjords, where only has been reported previously.

Contrasting physiological responses to future ocean acidification among Arctic copepod populations.

Widespread ocean acidification (OA) is modifying the chemistry of the global ocean, and the Arctic is recognized as the region where the changes will progress at the fastest rate. Moreover, Arctic species show lower capacity for cellular homeostasis and acid-base regulation rendering them particularly vulnerable to OA. In the present study, we found physiological differences in OA response across geographically separated populations of the keystone Arctic copepod Calanus glacialis.