<i>Thalassophryne maculosa</i> (Batrachoididae: Thalassophryninae) as a Bioindicator of Mercury-Induced Genotoxicity.

Abstract

Environmental monitoring requires reliable bioindicators to assess the genotoxic effects of pollutants in aquatic ecosystems. In this study, the marine fish <i>Thalassophryne maculosa</i> was evaluated as a bioindicator of genotoxicity through the application of the micronucleus test. Fish were exposed to varying concentrations of mercuric chloride (HgCl₂) (0.1, 0.25, and 0.5 µg HgCl₂/g body weight) over different time intervals (24, 48, 72, and 96 h). A dose- and time-dependent increase in nuclear abnormalities, including micronuclei, was observed, with significant chromosomal damage detected at 0.25 and 0.5 µg HgCl₂/g body weight. These results demonstrate the sensitivity of <i>T. maculosa</i> to mercury exposure, even at concentrations below regulatory safety thresholds, emphasizing its suitability as a bioindicator for detecting genotoxic contamination in coastal ecosystems. This study provides critical insights into the ecological risks posed by mercury and highlights the potential of <i>T. maculosa</i> to enhance environmental monitoring programs, particularly in regions vulnerable to heavy metal pollution.