Responses of Atlantic salmon alevins to temperature gradients

Abstract
Newly hatched Atlantic salmon (Salmo salar) alevins aggregated in the lowest temperature available in a temperature gradient, possibly because of lower levels of locomotor activity at lower temperatures. At approximately 250 degree-days after hatching, alevins demonstrated a temperature selection capability and no longer aggregated in the lowest temperature. Possible mechanisms underlying the observed distributional change in a temperature gradient are discussed.