Genotoxic Biomarkers in Fishes of the Chapada Das Mesas National Park, Brazil

Abstract

Genotoxic and hematological parameters in Hypostomus pusarum and Mylossoma duriventre were used as biomarkers to assess the exposure to environmental stressors within the Chapada das Mesas National Park (PNCM). Fishes were sampled at two sites in PNCM: São Romão and Prata Waterfall. Biometric data (length and weight) were recorded, and blood was collected from all fishes for analysis. The abiotic variables were measured in each region: pH, temperature and dissolved oxygen. A drop of blood from each fish was placed on two microscope slides and smeared. The slides were left to dry at room temperature for 24 h and then fixed in absolute ethanol for 30 min. Means and standard deviations (SDs) of the biometric data of H. pusarum showed length and total weight bigger than M. duriventre. Nuclear morphological changes (NMAs) were identified in the two sampled species for the two collection points. Among the NMAs found, binucleated nucleus (BN), vacuolated nucleus (VC) and micronucleus (MN) were also found in both species; however, in M. duriventre, the frequency of MN and NMA was higher than H. pusarum. The presented data show that methodologies based on biomarkers will be used in the future park management programs.