ABSTRACT

This chapter discusses the relationship between skin tumors of these fishes and the chemical constituents of the kraft pulp mill effluents, and the possibility of both fish species as biomarkers in the aquatic environment which is contaminated with chemcial substances. The epizootiological study showed that the geographic distribution of chrom-atophoroma in the croaker was greatest at the Pacific coastal area of Japan islands. The sea catfish having a skin lesion was also caught at the same area that the croaker inhabited. The geographic distributions of chromatophoroma in the croaker and skin pigment cell hyperplasia in the sea catfish were greatest. In the tumor induction test, using well-known carcinogens, chromatophoroma and melanosis were easily induced in the croaker and the sea catfish, respectively. The specific difference of sensitivity of carcinogens against each organ was observed in fish as shown in mammals. The metabolic activation of xenobiotics in fish may change depending on the species.