Effects of Diazinon on bluegill sunfish, Lepomis macrochirus , gills: scanning electron microscope observations

摘要: Gills of bluegill sunfish, Lepomis macrochirus, exhibited varied degrees structural damage following a 24-h exposure to sublethal concentrations (15 µg/1, 30 µg/l, 45 4g/1, 60 µg/1 and 75 µg/1) Diazinon [O,O-diethyl-O- (2-isopropyl-6-methyl-4 pyrimidinyl ester or phosphorothioate]. Exposure 15 resulted in exocytosis some material the cell surface perforations microridges. At higher doses (above µg/1), extrusion was reduced cells were swollen. Compared control values, thickness microridge on gill arch filament generally increased with Diazinon. Also, distance between microridges decreased concentrations. 60.tg/1, fused ridges filaments disappeared. exposure, epithelial became obscured severe cellular extrusions lamellar surfaces swelled. The mucus extrusion, swelling may be related defence mechanism which reduces water around increases barrier for diffusion toxicants from outside blood capillaries. Although this protects fish toxicants, it also oxygen supply leads suffocation fish.