BEHAVIORAL AND PHYSIOLOGICAL CORRELATES OF RECOVERY FROM EXHAUSTION IN LUNGLESS SALAMANDER BATRACHOSEPS-ATTENUATUS (AMPHIBIA PLETHODONTIDAE)

1. Slender salamanders, Batrachoseps attenuatus, underwent forced swimming until exhausted. Lactate elimination, rate of oxygen consumption ( {Mathematical expression}), and recovery from fatique were measured following exhaustion. 2. Ambient oxygen partial pressure ( {Mathematical expression}) during the recovery period (in air) affected recovery from fatigue, {Mathematical expression}, and lactate elimination (Fig. 1-3; Table 1). Recovery from fatigue at 1 h after exhaustion was positively correlated with {Mathematical expression}. 3. At 75 and 157 Torr {Mathematical expression}, more than 50% of recovery from fatigue occurred in the first 0.5 h after exhaustion (Fig. 4). Recovery from fatigue preceded lactate elimination during this period. All remaining recovery from fatigue required 4.5 additional hours, and occurred synchronously with lactate elimination. Recovery from fatigue was most rapid when {Mathematical expression} was highest. 4. Salamanders restimulated to activity after 0.5 h recovery produced no additional lactate (Table 2). Salamanders were active at whole-body lactate concentrations previously associated with exhaustion. Selective elimination of lactate from locomotor musculature did not occur (Table 2). 5. Oxygen debt functions in both recovery from fatigue and lactate elimination in Batrachoseps. Lactate concentration alone is an inadequate explanation for fatigue and recovery in all amphibians. © 1978 Springer-Verlag.