The effect of water-soluble aromatic hydrocarbons on some haematological parameters of rainbow trout, Salmo gairdneri Richardson, during acute exposure

Rainbow trout were exposed to a model mixture of water-soluble aromatic hydrocarbons (AH) at concentrations of 0.3–15.2 ppm for periods of 1–72 h. None of the parameters monitored except RBC changed at 0.3 ppm AH, while all constituents, except blood glucose, changed at 7.2 ppm AH. At 15.2 ppm, all fish died within 1 h. Haematological changes included increased haematocrit, haemoglobin concentration, erythrocyte counts, and blood clotting (prothrombin) times. Plasma Cl⁻ concentration decreased significantly. Changes resembled a stress response except for the increased clotting times, which typically decrease, and lack of increase in blood glucose.