The effect of temperature on tail beat frequency of fish swimming at constant velocity

Abstract

Rainbow trout and largemouth bass were swum at fixed swim speeds from one to three body lengths per second at ambient water temperatures from 5 to 35 °C. Tail beat frequency was measured during steady swimming. Both tail beat frequency and stride length (distance moved per tail beat) increased with increased swim speed. In trout tail beat frequency was lower at higher water temperatures, whereas in bass tail beat frequency was higher at higher water temperatures. In both trout and bass tail beat frequency was lower in fish acclimated to a higher temperature. I suggest that when test temperature is above acclimation temperature the muscle operates high on the force–velocity curve; and when test temperature is below acclimation temperature the muscle operates low on the force–velocity curve.