STRESS RESPONSES IN RAINBOW-TROUT ONCORHYNCHUS-MYKISS ALEVINS

1. Rainbow trout alevins were subjected to either mechanical chasing, acute anoxia or were exposed to elevated sodium chloride levels and the subsequent changes in metabolic profiles were determined. 2. In general, juvenile fish stimulated to strenuous exercise seem to mimic the stress response known in adult trout, albeit on a miniaturized scale, both in time and in terms of absolute metabolite concentrations. 3. Under acute anoxia the alevins are capable of extending their anaerobic stamina, mainly by the formation of IMP. During recovery this process is fully reversed, with replenishment of the adenylate pool being completed after 15 min. 4. Exposure to 5 ppt NaCl provokes the formation of lactate under fully aerobic conditions. A marked decrease in glucose may point to an elevated energy requirement due to osmoregulatory processes.