Oxygen consumption in relation to motion of marine planktonic copepods

The goal of these studies was to quantify the energy consumption of abundant marine planktonic copepods with different motion behaviors but similar body weight by determining their oxygen consumption under conditions approaching those encountered in their natural environment. The motion behaviors of adult females of the 3 copepod taxa studied ranged from the continuously fast-moving Clausocalanus furcatus to the continuously slow-moving and feeding current-producing Paracalanus aculeatus to the occasionally moving Oncaea spp. At 20 degrees C, the daily oxygen consumption per unit body weight decreased significantly with decreasing activity, i.e. C. furcatus > P. aculeatus > Oncaea spp. Expressed as percent of body carbon metabolized per day, the average values were 23.4% for C. furcatus, 15.1% for P. aculeatus, and 10.5% for Oncaea spp. Oxygen consumption of P. aculeatus and Oncaea spp. was significantly higher at 23 degrees C than at 20 degrees C. It is concluded that not only body weight and temperature, but also the extent of motion will affect energy expenditures of planktonic copepods.