Anaerobic Metabolism during Activity in Amphibians

1. Total lactate production (anaerobic energetic generation) during maximal activity was measured in eight species of amphibians. 2. Slow-moving animals, exemplified by Bufo boreas, produce small amounts of lactate and do not exhaust. In contrast, fast-moving, saltatory forms, such as Rana pipiens and Batrachoseps attenuatzls, have high levels of lactate generation and are unable to sustain maximal activity. 3. Aquatic species rely on air gulping during activity and show little anaerobiosis. 4. The temperature dependence of anaerobic energy generation is high (Q,, = 1.5-3-9) for all species. 5. Levels of amphibian lactate production are lower than those of lizards and show greater interspecific variation. 6. The rate of lactate production is directly correlated with predator avoidance. Noxious-tasting or aggressive amphibians have low anaerobic scopes; others rely on anaerobiosis for energy for rapid flight. Rapid activity in amphibians appears possible only at the expense of extensive anaerobiosis.