Effect of organomercurial poisoning on the peripheral blood and metabolite levels of a freshwater fish.

This work evaluated the hematological and biochemical changes in the fish, Puntius conchonius, under experimental organomercurial poisoning. Long-term (8 weeks) exposure to 3.63 and 6.03 mg/liter methoxyethyl mercuric chloride (MEMC) (0.2 and 0.33 fractions of 96-hr LC50) led to morphological aberrations in mature erythrocytes including nuclear and cytoplasmic deterioration, vacuolation, chromatin condensation, and hypochromia. Immature erythrocytes showing membrane leakage were also encountered. Erythrocyte count and hemoglobin (Hb) were significantly lowered after 1 and 3 weeks followed by a marginal rise persisting upto 8 weeks. Differential leucocyte counts revealed significant thrombocytopenia, lymphocytosis, and neutropenia. Collateral evaluation of blood glucose and tissue glycogen levels revealed significant hyperglycemia as well as glycogen depletion in liver and brain. Heart glycogen content evinced a substantial increase after 5 and 8 weeks exposure.