Metabolic power-time curves of mitochondria isolated from fish liver tissue of six species (Cyprinus carpio Val, Scattered-scaled mirror carpio, Cyprinus carpio red variety, Carassius auratus gibelio, Carassius auratus transparent colored variety, Carassius auratus red variety) where determined by the LKB-2277 bioactivity monitor. From them the rate constants of the activity recovery phase (k) and the total heat (Q) released during the experiment time were obtained. The results indicate that a fish with both larger k and Q values has a higher growth rate. Heterosis can be achieved when a male parent line with large k value and a female parent line with large Q value were used. We believe that the amount of total heat released indicates the metabolic activity of a species while the rate constant of activity recovery phase represents its adaptive capacity to environment.

Key words: MITOCHONDRIA, HYBRIDIZATION, METABOLISM, BIOLOGICAL ACTIVITY