Anaerobic capacity and swim performance of juvenile salmonids

Abstract

This study describes the development of procedures for the assessment of anaerobic capacity and swim performance in juvenile Atlantic salmon (Salmo salar), rainbow trout (Oncorhynchus mykiss), and brook trout (Salvelinus fontinalis). Three exercise tests, with exhaustion as an end point, were evaluated: a fixed-duration, high-intensity exercise; a fixed-velocity exercise; and an incremental-velocity exercise. Muscle (or whole body) lactate, phosphocreatine (PCr), and ATP were used to calculate, in ATP equivalents, the anaerobic energy expenditure (AEE, in µM ·g-1or µmoles) and to document the recovery from exhaustion. AEE was maximal in the first of these tests and submaximal in the second. Recovery was characterized by rapid restoration of PCr, slower recovery of ATP and lactate, and even slower recovery of glycogen. Mathematical expressions were developed to express the rates of recovery and thereby permit intra- and inter-species comparisons. Body size was the most important determinant of performance. Anaerobic capacity (AEE in the fixed duration test), sprint duration at fixed velocity, and maximum swimming speed scaled as length L4to L5, L4to L5, and L1.3, respectively. Each of these tests are effective measures for evaluating intra- and inter-specific differences in anaerobic capacity and swimming performance providing correction is made for the large scaling coefficients.