Genotoxicity in Oreochromis niloticus (Cichlidae) induced by Microcystis spp bloom extract containing microcystins

► Microcystin showed genotoxicity to Oreochromis niloticus fish. ► Microcystin body exposure resulted in micronucleus induction and DNA damage. ► At lower concentrations more apoptosis than necrosis occurred. ► At higher concentrations more necrosis was observed.