A model of growth suppression in rainbow trout (Oncorhynchus mykiss) associated with a high dose of hydrogen peroxide exposure with evaluation of selected hormonal and blood chemical constituents

Hydrogen peroxide is an oxidizing compound which has been used as a therapeutic agent to control sea lice infestations of salmonids. However, it is known that concentrations needed to control these copepods may cause serious branchial injury. The effect of this treatment on fish growth performance is unknown. In this thesis, a treatment simulation model, in which rainbow trout (Oncorhynchus mykiss) juveniles reared in fresh water received a single exposure to hydrogen peroxide at 1250 ppm for 30 min, was used in order to develop an understanding of the interaction of this treatment with salmonid growth performance. The growth performance of fish before and after treatment was compared with that of untreated fish held in separate tanks and in a cohort design in which treated fish co-habitated with untreated fish. Other studies were designed to investigate whether growth alterations were related to disturbances in hormonal and blood chemical compounds. Based on our results, we conclude that the activation of the primary and secondary stress response, and alteration of the gill morphology may be, in part, contributory factors in the transient decreased growth performance associated with a single high dose of hydrogen peroxide. (Abstract shortened by UMI.).