Author(s): Wannee Jiraungkoorskula, E Suchart Upathama, Maleeya Kruatrachuea, Somphong Sahaphong, Suksiri VichasriGrams
The acute toxicity of Roundup, a glyphosate herbicide, to Nile tilapia, Oreochromis niloticus, was investigated with emphasis on histopathological effects. The values of 24-h, 48-h, 72-h and 96-hLC50 for young tilapia were 17.5, 17.1, 16.9 and 16.8 ppm, respectively, and those for adult tilapia were46.9, 44.4, 40.0 and 36.8 ppm, respectively. They indicated that adult fish were more tolerant to Roundupthan the much smaller young fish. Roundup concentration corresponding to the 96-h LC50 value foradult tilapia was used to study the effects of Roundup exposure in inducing histopathological changesof gills, liver and kidneys. In the gills, filament cell proliferation, lamellar cell hyperplasia, lamellarfusion, epithelial lifting and aneurysm were observed. In the liver, there was vacuolation of hepatocytesand nuclear pyknosis. Kidney lesions consisted of dilation of Bowman’s space and accumulation ofhyaline droplets in the tubular epithelial cells. These changes occurred predominantly in the 96-hexposure.