Among the new substances that were synthesised by the chemical industiy during the last decades, with the aim to improve human prosperity, some cause negative effects on non target organisms like fish. Among the pesticides, the organophosphates (OP) are widely used in cattle management, agriculture and aquaculture activities. Brachydanio rerio Hamilton-Buchman, 1822 is used world-wide in fish-tests for the establishment of the lethal levels of pesticides. Nevertheless, these fish show morphological changes in their hepatocytes when exposed experimentally for 24 hours to the sublethal dose of 0.025 µl/l of the OP Dimethoate 500, in acute tests. Right hours after exposure, a high density of cells with cytoplasmic granulation is seen as well as focal... |