Diel vertical migration of a Southern Ocean euphausiid, Euphausia triacantha, and its metabolic response to consequent short-term temperature changes

Diel vertical migration is a widespread behaviour amongst zooplankton, yet its effect on the rate at which individuals respire remains poorly understood. To address this, we investigated of short-term temperature change respiration Euphausia triacantha , common component Southern Ocean zooplankton and prominent migrator. We found to vary in response size, with value 0.84 for scaling coefficient, b . When scaled varied strongly transitory change, ranging from 0.37 1.65 µl O 2 mg dry weight (DW) - h -1 between 0.17 4.74°C, resulting Q 10 3.6. This higher than by other studies examining euphausiids, including those taking multi-species perspective. indicates that E. shows little compensation during exposure temperatures normally encountered migration. Furthermore, it distinct metabolic cost diel (DVM) when substantive changes are over course transit. temporal variability has important implications how community estimated, our understanding DVM behaviour. Our results also have particular relevance estimating flux sequestration respiratory products, such as dissolved carbon dioxide, within ocean interior.