Anaerobic metabolism and behavior during predatory encounters between snakes (Thamnophis elegans) and salamanders...

1. We staged predatory encounters between snakes and salamanders in the laboratory. 2. Both snakes and salamanders accumulated significant quantities of lactic acid (0.3-2.3 mg/g) during predatory encounters. In a typical 14.4 min encounter, lactate concentration reached 260% of resting levels in snake predators and 880% of resting levels in salamander prey. This is one of the first demonstrations of anaerobiosis during natural 'burst' activity in both predator and prey. 3. Salamander responses to snake attack were surprisingly variable, and included writhing, thrashing, tail wrapping, tail autotomy, and biting. Antipredator responses were effective in nearly one third of trials. Lactate concentration was significantly correlated with duration of predatory encounters (r=0.57), snake mass, and salamander mass (Table 3). 4. Our calculations suggest that attack and ingestion of prey may cost snakes less than 1% of energy assimilated from prey.