Recovery from Exhaustive, Anaerobic Exercise in Triploid and Diploid Atlantic Cod

Using sterile triploids can reduce environmental impacts of aquaculture, but the physiology of triploids and diploids differ and may therefore affect triploid performance. In this study, we investigated the recovery from exhaustive, anaerobic exercise in diploid and triploid Atlantic cod (Gadus morhua).

Cod swam to exhaustion in a large swim tunnel (1.5 m³chamber) at continuously increasing speed (0.1 to 1.2 m/s over 11 min) and were immediately sampled or allowed to recover for 1, 2, 4 or 8 hours before sampling.

Diploids (54.1±0.5cm; 1704±46g; mean±sd) were longer and heavier than triploids (51.8±0.5cm; 1430±47g), but ploidy did not affect relative exhaustion speed (1.82±0.29 BL/s) or post-exercise recovery of blood parameters. Blood lactate increased during exercise and was higher than the resting control (0.4±0.2 mM; mean±se) directly after exhaustion (1.3±0.2) and after one (1.9±0.2) and two (1.2±0.2) hours of recovery. Blood glucose did not change during swimming, but increased afterwards, and was higher than the control (3.4±0.4 mM) after two (5.0±0.4) and four (4.8±0.4) hours of recovery.

Between four and eight hours is sufficient for cod to recover from exhaustion, regardless of ploidy. Thus, triploids should be as well suited to culture as diploids in terms of recovery from exhaustive stressors.