Anaemia in the freshwater catfish Clarias albopunctatus (Teleostei: Clariidae) exposed to brewery wastewater effluent

Abstract

Haematological changes were studied in freshwater catfish Clarias albopunctatus exposed for 20 days to 25%, 50% and 100% concentrations of brewery wastewater prepared by dilution using tap water. Haemoglobin, haematocrit and erythrocyte counts in fish exposed to wastewater were significantly lower than in a control group. There was a significant increase in the total leucocyte counts in treated fish, which also suffered microcytic anaemia. The observed changes in the haematological parameters of the fish exposed to brewery wastewater may represent part of the physiological processes by which the wastewater exerts its deleterious impacts on the fish.