The usefulness of histopathology in aquatic toxicity studies.

1. A survey was carried out to examine the usefulness of histopathology for the identification of toxic effects of environmental contaminants in fish. 2. Two small fish species, Poecilia reticulata (guppy) and Oryzias latipes (medaka) were used, and two exposure periods (1 and 3 months) were chosen. 3. The following compounds were studied: beta-hexachlorocyclohexane, bis(tri-n-tributyltin)oxide, di-n-butyltindichloride, sodium bromide, methyl bromide, and methylmercury chloride. 4. The following is concluded: histopathology provides useful data in characterizing toxic effects in fish; there is a slight advantage for Poecilia reticulata over Oryzias latipes; there is no advantage for 3 months exposure vs 1 month.