Multibiomarker approach in a neotropical fish to evaluate an urbanized river

Area of Science:

• Environmental toxicology
• Aquatic ecotoxicology
• Genetics and biochemistry

Background:

• Agricultural and urban waste contaminate aquatic ecosystems daily.
• Anthropogenic activities pose threats to aquatic species and ecosystem integrity.
• Hypostomus ancistroides, a benthic neotropical fish, is susceptible to mutagenic pollutants due to its feeding habits.

Purpose of the Study:

• To assess the genotoxic and biochemical toxicity of urban and rural river waters.
• To evaluate the effects of river water contamination on Hypostomus ancistroides.
• To compare contamination levels between urbanized and rural river points in Toledo, Paraná, Brazil.

Main Methods:

• Collection of Hypostomus ancistroides from urban (P1, P2) and rural (P3) river sites.
• Analysis of genotoxic biomarkers: frequency of micronuclei (MNs) and erythrocyte nuclear abnormalities (ENAs).
• Biochemical biomarker analysis: superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and lipid peroxidation (LPO) across seasons.

Main Results:

• Genotoxicity (MNs and ENAs) was observed in fish from both urban and rural areas, with peak occurrence at P2 during winter.
• Increased SOD activity was noted in summer at P2; CAT activity showed no significant difference.
• Elevated lipid peroxidation occurred in winter at P2 and P3, while higher GST activity was found in winter at P1 and P2.

Conclusions:

• Both Toledo and Santa Quitéria rivers are impacted by human contamination, especially during winter.
• Site P2 exhibited the highest genotoxicity, signifying a substantial risk to local aquatic organisms.
• The study highlights the significant genotoxic and biochemical stress on Hypostomus ancistroides due to river water contamination.