The effects of microcystins on the serum biochemistry of carp, Cyprinus carpio L, when the toxins are administered by gavage, immersion and intraperitoneal routes

Microcystins were administered to carp, Cyprinus carpio L., by intraperitoneal injection. Tests performed on the serum indicated liver and gill damage, and disturbances in hepatic and osmoregulatory functions. Exposure of carp to microcystins by gavage and immersion caused changes indicating mild liver damage and changes in the equilibrium of cation-anion balance in some treatments. The results of gavage and immersion exposure indicate that acute toxicity is unlikely to occur in wild carp populations, but chronic poisoning may follow repeated sublethal exposure. A serum biochemical profile comprising alanine amino transferase, aspartate amino transferase, bile acids, bilirubin, sodium and chloride determinations may provide a useful diagnostic indication of microcystin poisoning in wild carp populations.