[Effect of monocrotophos on Na+/K(+)-ATPase activity and ultramicrostructure of Sciaenops ocellatus branchiae].

The exposure of Sciaenops ocellatus to monocrotophos at its concentration of 0.25, 0.5, 1.0 or 2.0 mg L-1 for 4 days demonstrated that under the stress of low concentration (0.25 mg.L-1) monocrotophos, the chloride cells of branchiae proliferated, accompanied with the increase of Na+/K(+)-ATPase activity, while under high concentrations of monocrotophos, the damage of gill was much heavier, and the Na+/K(+)-ATPase activity also decreased. The damage in gill under sublethal monocrotophos exposure included hypertrophy and edema, and thus, the lamellar epithelium became thick and lifting, and the lamellae were bulbing or fusing. The ultramicrostructural changes of the gill of the exposure fish were the swollen and even rupture of rER, mitochondria, microtubule and nuclear membrane.