Genotoxicidad de cloruro de mercurio (II) en alevines de Oreochromis niloticus (Pisces, Cichlidae) expuestos a diferentes temperaturas

Abstract

Mercury chloride (HgCl<inf>2</inf>) is a neurotoxic, nephrotoxic, and genotoxic compound found in aquatic environments due to anthropogenic activities and whose effect can be altered by variations in temperature (for example: global warming). The aim of this work was to determine the mean lethal concentration (LC<inf>50</inf>) for HgCl<inf>2</inf> and its genotoxic effect, inrelationtotheincreaseintemperaturefor Oreochromis niloticus fingerlings. The LC<inf>50</inf> results for HgCl<inf>2</inf> during the exposure times (48, 72, and 96 h) and temperatures (28 and 32 °C) showed that the LC<inf>50-96h</inf> increased from 0.39 mg L<inf>-1</inf> for 28 °C to 0.66 mg L-1 for 32 °C. For sublethal evaluation, HgCl<inf>2</inf> concentrations from LC<inf>50-96h</inf> were established for 28 and 32 °C, evaluating genotoxicity for 30 days through the nuclear abnormalities (AN) and micronucleus (MN) assay. A higher frequency of AN and MN was observed at 0.07 mg L-1 of HgCl<inf>2</inf> for 32 °C. It is concluded that the LC<inf>50</inf> and genotoxicity (AN and MN) for HgCl<inf>2</inf> increase with increasing temperature from 28 to 32 °C.