Sanchez J G, Speare D J, Sims D E, Johnson G J
Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Canada.
J Comp Pathol. 1998 Jan;118(1):81-7. doi: 10.1016/s0021-9975(98)80032-7.
Juvenile rainbow trout were exposed to therapeutic concentrations of formalin or chloramine-T to assess the effects of these chemicals on the morphology of the piscine epidermis and its mucous coat. Repeated treatment, once weekly for 4 weeks, with either chemical did not affect the mucous coat of the epithelium or the degree of folding of the basal lamina. However, treated fish had increased numbers of highly dense vesicles within the apical portions of epithelial cells. The epidermal mucous cells of chloramine-T-treated fish were significantly smaller than in controls. This effect was not noted in formalin-treated fish. Treatment with either chemical resulted in a significantly thinned epidermis. It is concluded that although chloramine-T and formalin may continue to be useful in the aquaculture industry they cause potentially harmful alterations to fish skin.