Ultrastructural changes in the respiratory lamellae of the catfish, Heteropneustes fossilis after sublethal exposure to malathion.

摘要: Abstract Transmission electron microscopy study of the gills Heteropneustes fossilis, exposed to 4 mg/liter malathion ( 1 3 LC50) for 24, 48, 72, and 96 h showed significant changes in its ultrastructures. Exposure pesticide after 24 caused a slightly disarrayed condition double layered epithelial structure. Lymphatic spaces became more apparent, few chloride cells appeared which protruded toward peripheral margin secondary lamellae. Chloride were exterior by an apical pit. Pinocytosis was observed with marginal folds (MF) originating from pillar cells. Some vascular constrictions also seen capillaries erythrocytes. After 48 exposure, outer stretched into thin boundary wall lymphatic engorged plasma exudate. transversed whole epithelium lamella came direct contact lymphoid space lining. Basement membrane thicker. 72 distorted lamellar ruptured places allowing many spheroid bodies some come out. Marginal migrated spaces. thicker blood channels constricted causing stasis. No erythrocytes visible. Blood filled leukocytes amoebocytes. exposure narrowing spaces, proliferation development pinocytotic vesicles cell flanges observed. Only maintained normal configuration. Vascular stasis due thickening basal lamina still evident centrally located leukocytes. would likely cause decrease respiratory efficiency. This has revealed that H. fossilis affected sublethal dose malathion. The ultrastructural damages as early at but most severe damage occurred exposure. However, signs gill structure regeneration malathion-exposed fish h.