Histological, Genotoxic, and Biochemical Effects onCnesterodon decemmaculatus(Jenyns 1842) (Cyprinodontiformes, Poeciliidae): Early Response Bioassays to Assess the Impact of Receiving Waters

Abstract

In the present study, the toxicity of receiving waters from a highly polluted urban watercourse, the Reconquista River, Argentina, collected at a dam in the upstream part of the river was evaluated. Cnesterodon decemmaculatus, a widely distributed fish species in Pampasic rivers proposed for use in ecotoxicological evaluations, was used as a test organism. A 96-h acute toxicity bioassay with river water quality which has been characterized as moderately contaminated was performed. The treatment groups were (1) whole surface river water; (2) whole surface river water with 2 mg Cd/L added as a simulated metal contaminant pulse; (3) a negative control using reconstituted moderately hard water (MHW); (4) a metal positive control, MHW + 2 mg Cd/L; and (5) a positive genotoxicity control, MHW + 5 mg Cyclophosphamide/L (CP). The condition factor rate, micronuclei frequency, and comet assay from peripherical blood, structural changes of the gill arrangement by scanning electron microscope (SEM) analysis, histopathological changes in the liver and the glutathione-S-transferase, catalase, superoxide dismutase, glutathione, and protein content from the body midsection (viscera) were evaluated. According to our results, for short term exposure, SEM analyses of gills and liver histopathological analyses could be useful tools for the evaluation of target organ damage as well as comet assays for DNA damage. We propose that the 96-h laboratory bioassay protocol described is useful for monitoring the deterioration of water quality employing the teleost C. decemmaculatus and that the microscope analysis of gills and liver as well as the comet assay methodology could be sensitive endpoint indicators.

A biomonitoring study: Using the biomarkers in Cyprinus carpio for the evaluation of water pollution in Sapanca lake (Sakarya, Turkey)

“…Fusion plays a major role at this point; because fused lamellae reduce the exposure surface. The labefaction due to the shortening in the fusion extension in the lamellar sizes can also be compensated by hyperplasia, hypertrophy, and edema (Ossana et al, 2019).…”

Biomonitoring of Alterations in Fish That Inhabit Anthropic Aquatic Environments in a Basin from Semi-Arid Regions

“…On the other hand, when we compare our results with other studies carried out on bioindicator species of fish used in the Neotropical region, such as Cnesterodon decemmaculatus , we observed similar results. For example, in studies where biomarkers are used at the individual, biochemical, and cellular levels for laboratory bioassays carried out with samples from rivers and effluents, alterations were observed only in cellular and biochemical biomarkers due to physicochemical parameters and metals [ 48 , 49 , 50 , 51 , 52 ]. Added to this, other laboratory studies with river water corroborate that water toxicity varies widely both spatially and temporally, suggesting intermittent toxic spillage, as confirmed by analyzing variations in the measured sample physiochemical parameters [ 53 ].…”

Evaluation of the Acute Effects of Arsenic on Adults of the Neotropical Native Fish Cnesterodon decemmaculatus Using a Set of Biomarkers

“…We used the micronucleus and nuclear abnormality tests as genotoxicity biomarkers following the procedure of Schmidt (1975), with slight modifications by Ossana et al (2019) and Bonifacio et al (2020). Smears from peripheral blood were air‐dried and fixed with 100% (v/v) methanol at 4 °C for 20 min and then stained with 5% Giemsa solution.…”

“…The alkaline comet assay was performed following the procedure proposed by Singh et al (1988) with slight modifications by Ossana et al (2019). Briefly, a drop of blood from the same specimens as used for the micronucleus and nuclear abnormality tests was diluted with 1 ml of phosphate‐buffered saline (PBS) and centrifuged at 2000× rpm for 8 min.…”