Profile of micronucleus frequencies and nuclear abnormalities in different species of electric fishes (Gymnotiformes) from the Eastern Amazon

Abstract

The frequency of spontaneous micronucleus (MN) formation in fish species needs to be determined to evaluate their usefulness for genotoxic biomonitoring. The definition of a good bioindicator takes into account the current knowledge of its metabolic traits as well as other factors including its feeding behavior and relationship to the environment. In this study, we compared the basal frequencies of micronucleated erythrocytes and nuclear abnormalities (NA) among different species of the fish Order Gymnotiformes (Rhamphichthys marmoratus, Steatogenys elegans, Sternopygus macrurus, Parapteronotus hasemani, Gymnotus mamiraua, Gymnotus arapaima, Brachyhypopomus beebei, Brachyhypopomus n. sp. BENN) sampled in several localities of the Eastern Amazon. A baseline of MN and NA frequency in these fish was determined, enabling the identification of potentially useful species as models for genotoxicity studies. Only one impacted sample collected at a site in the River Caripetuba showed a significant number of NAs, which may be due to the release of wastewater by neighbouring mining industries and by the burnt fuel released by the small boats used by a local community. Our results may provide support for further studies in areas of the Eastern Amazon affected by mining, deforestation and other anthropogenic activities.

Genotoxicity of gold nanoparticles in the gilthead seabream (Sparus aurata) after single exposure and combined with the pharmaceutical gemfibrozil

“…The mechanism of GEM genotoxicity is probably multifactorial, based on the available studies with mammals; the effects may be due to oxidative stress or formation of reactive metabolites binding to DNA and causing adduct formation [78]. Considering that the responses of fish to contaminants, in terms of genetic damage, are similar to those of other vertebrates, including humans [79], fish species may be useful model organisms for risk-assessment studies.…”

Environmental biomonitoring using different biomarkers and their contribution in aquatic environmental research

“…Blood cells from kidney were used and the maximum effect was observed at 24.48% concentration after 96 hours of exposure. Melo et al (2013) [56] found the usefulness of the micronucleus assay for genotoxic biomonitoring and compared the frequencies of micronucleated erythrocytes and nuclear abnormalities among different species of the electric fish of order Gymntifomes collected from localities of Eastern Amazon. Only one sample collected from the impacted site in the River Caripetuba showed a significant number of NAs which was due to waste water from neighboring mining industries and by burnt fuel released by the local community.…”