BIOLOGICAL STUDIES ON THE RED SWAMP CRAWFISH PROCAMBARUS CLARKI/ (GIRARD, 1852) (DECAPODA: CAMBARIDAE) IN THE RIVER NILE, EGYPT

Abstract

The present study dea_ls with the physiological changes in the haemolymph, hepatopancreas and muscles of the red swamp crawfish Procambarus clarkii exposed to the organophosphorous pesticide malathion in acute and chronic doses during different time intervals.

• This study showed that malathion is toxic to P. clarkii, the 96 hrs LCso being 3.706 rng/1 (ppm). The results revealed that there was a highly significant elevation in haemolymph glucose, ASAT, ALAT enzymes, creatinine, uric acid and potassium concentrations after acute and chronic exposure to malathion. However, a gradual decrease was recorded in the haemolymph total lipid and sodium concentrations but a sudden increase was encountered after 6 weeks of chronic exposure.

Hepatopancreatic analysis of P. clarkii showed a decrease in the water content, total protein, glycogen, 11epatosomatic index (HSI) and cholesterol after exposure to acute and chronic doses of malathion. However, an increase was recorded in the total lipid concentrations. Hepatic and muscle ASAT and ALAT showed a significant decrease throughout the entire experimental period of acute and chronic exposure to malathion.