BISHOP, Renee E.; GEIGER, Stephen P.; MC CULLON, Joseph Jr.: Phronima Energetics: Life of a planktonic stowaway

The hyperiid amphipods of the genus Phronima have adapted to the pelagia by hollowing transparent barrels from salps. The amphipods reside in the salp barrels and pilot them through the water. This unique behavioral adaptation may provide advantages to the Phronima with regards to their energy requirements. The metabolic rates of four species of Phronimacollected in Exuma Sound, Bahamas, were determined. Oxygen consumption was measured directly using microcathode oxygen electrodes. In addition, activities of three key metabolic enzymes; citrate synthase, lactate dehydrogenase, and malate dehydrogenase were determined. Both oxygen consumption and enzyme activities of the Phronima were compared to rates of other plnaktonic crustaceans to determine if the energy requirements of an organism with this unusual lifestyle are lower than other planktonic crustaceans.