Adaptation changes in channel catfish yearlings at infection by the parasitic infusoria Ichthyophthirius multifiliis Fouquet

Influence of different levels of invasion by the parasitic infusoria Ichthyophthirius multifiliis Fouquet on some tnorphometric and biochemical indices of channel catfish yearlings at their infestation has been studied under experimental conditions. Adaptation changes in the protein content and activity of hydrolases were determined in internal organs and muscles of fishes at intensity of invasions by Ichthyophthirius ca. 1-50 individuals per one fish. Besides biochemical changes, for channel catfishes at intensity of invasions by Ichthyophthirius ca. 51-550 individuals, changes in mass, length, and the fatness index were revealed.