| Acclimation of the waterflea Daphnia magna Straus (Crustacea: Cladocera) at 2 o to 12 o C above their habitat temperature (16 o C) for 6 months increased the rate of their metabolic activity (respiration and heartbeat rates). Temperature-enhanced activity appeared to be supported by cellular ATP synthesis (increased cytochrome c oxidase and succinic dehydrogenase activities) and hydrolysis (increased ATPases activities), indicating high rate of intermediary metabolism, the substrates for which may come from the stored glycogen and fat in addition to ingested food. Temperature-enhanced activity was associated with loss of body mass and decrease in body size, both of which may result from hyperactivity (causing lack of replenishment of consumed stored... |
