Genotoxic alterations as biomarkers in fish from a protected area in southern Maranhão, Brazil

Abstract

Abstract This study aimed to evaluate genotoxic biomarkers for monitoring two points in the Chapada das Mesas National Park (PNCM). Specimens of Leporinus taeniofasciatus and Hypostomus punctatus were collected in two waterfalls of the PNCM: Cachoeira São Romão (SRW) and Prata (PW). The stations were georeferenced by GPS (Global Position System) and in each region the physical-chemical parameters were recorded: pH, temperature, total dissolved solids (TDS), dissolved oxygen (DO) and conductivity. Biometric data were measured in the field. The blood of the animals was collected from the blood vessels of the gills, and the slides were made from the blood smear, with Giemsa staining, and 2000 cells were quantified per slide. Nuclear morphological alterations (AMN) were identified in the two species sampled for the two collection points. Among the AMN found, the following stand out: binucleated nuclei (NB), vacuolated nuclei (NV). Micronuclei (MN) were also found in both species, however, in L. taeniofasciatus the frequency of MN and AMN were higher in relation to H. punctatus. Probably, H. punctatus for being considered a benthic species and resistant to environmental conditions, presenting a lower frequency of genotoxic alterations in relation to L. taeniofasciatus, which is a species that presents a migratory habit and is sensitive to environmental variables. In addition, the frequency of MN and AMN were not significant to indicate possible environmental impacts in the two sampled areas. The data presented show that methodologies based on biomarkers in resident species can be used in future biomonitoring and park management programs.