Exercise training and the stress response in rainbow trout, Salmo gairdneri Richardson

Abstract

Plasma levels of catecholamines, cortisol, and glucose were monitored in rainbow trout during a 6-week forced swimming exercise programme. Compared to resting non-exercised controls, resting trained fish had lower levels of epinephrine, norephinephrine, cortisol, and glucose during the last 3 weeks of training. Initially, trained fish that were swimming had higher levels of epinephrine than resting trained fish. After 2 weeks of exercise, swimming did not significantly elevate epinephrine levels in trained fish. Glucose levels were consistently greater in swimming fish than in resting fish. At the end of the training period, exercised trout had lower (1 5-20%) oxygen consumption rates while resting or swimming than unexercised fish.After a 5-month forced swimming exercise programme plasma levels of catecholamines and glucose were monitored in trained and untrained cannulated rainbow trout after 2 min of mild agitation. Trained fish showed an immediate (within 1 min) increase in the levels of epinephrine, but not norepinephrine and a delayed (within 15 min) increase in the levels of plasma glucose.Epinephrine levels returned to pre-stress levels within 15 min. Untrained fish had no significant increase in the plasma levels of norepinephrine, epinephrine, or glucose.

Stress-associated impacts of short-term holding on fishes

“…Water velocities, in which fish can maintain their position, also benefit in saving energy by ventilating their gills by the flowing water (i.e., ram ventilation) and reduce their oxygen demand (Losordo and Westers 1994). Exercise conditioning has demonstrated increased red and white muscle activity, enhanced cardiac output and oxygen carrying capability in the blood (Nahhas et al 1982;Woodward and Smith 1985;Losordo and Westers 1994).…”

Predator-driven intra-species variation in locomotion, metabolism and water velocity preference in pale chub (Zacco platypus) along a river

“…The mechanisms underlying variation in swimming performance involve morphology, physiology, biochemistry and the neuroendocrine system (Woodward and Smith, 1985;Langerhans et al, 2004;Domenici et al, 2008;Fu et al, 2011b;He et al, 2013). Energy metabolism during swimming has been attracting considerable attention as a result of its close correlation with swimming performance (Webb, 1973;Dickson et al, 2002;Fu et al, 2011b).…”

Effect of a sprint training protocol on growth rate, conversion efficiency, food consumption and body composition of rainbow trout, Salmo gairdneri Richardson

“…Catecholamines are known to suppress appetite in mammals (Russek & Pina, 1962). In rainbow trout they cause increased free fatty acids and plasma glucose (Woodward & Smith, 1985). Furthermore, elevated lactate levels following intense activity last up to 24 h in the rainbow trout (Milligan & Wood, 1986).…”

“…Presumably, the increasing conversion efficiencies and subsequent increasing growth rates are due to fish habituating to the stresses induced by our experimental design. Woodward & Smith (1985) found that catecholamine release decreased over a period of weeks in both control and exercised trout as they adapted to holding and training. The increased conversion efficiencies, and generally decreased maintenance rations, noticeable after the first two weeks in the present study, support the habituation hypothesis.…”