Uptake, distribution in different tissues, and genotoxicity of imidacloprid in the freshwater fish Australoheros facetus

Abstract

The neonicotinoid imidacloprid is under re-evaluation by regulatory agencies because of the poor current information available regarding its potential effects. One of the goals of the present study was to determine imidacloprid uptake and distribution in the freshwater fish Australoheros facetus experimentally exposed for 24 h and 48 h to 100 μg/L, 300 μg/L, and 2500 μg/L. The toxicity of imidacloprid to fish reported in the literature is in the milligrams per liter or gram per liter range, but sublethal effects at micrograms per liter in some groups other than fish have been described. Another goal of the present study was to evaluate imidacloprid's potential genotoxicity and to compare it between the individual compound and a commercial formulation. Concentrations of imidacloprid were measured in water, brain, muscle, gills, gut, liver, and blood by liquid chromatography-tandem mass spectrometry. Imidacloprid was detected in all the tissues tested. Concentrations were higher after 48 h than after 24 h in liver, gills, gut, and muscle, whereas in brain and blood they were similar at both exposure times. Although there was no accumulation, only uptake, of imidacloprid, genotoxicity was observed. In fish exposed to IMIDA NOVA 35 , increased micronucleus frequency at 100 µg/L and 1000 µg/L was detected, whereas in the imidacloprid active ingredient bioassay it increased only at 1000 µg/L imidacloprid. The present findings warn of the possible consequences that fish living in freshwater ecosystems can suffer. Environ Toxicol Chem 2017;36:699-708. © 2016 SETAC.

An update of the Worldwide Integrated Assessment (WIA) on systemic insecticides. Part 2: impacts on organisms and ecosystems

“…Similar genotoxic and cytotoxic effects occurred in carp Cyprinus carpio and silver catfish Rhamdia quelen exposed to fipronil (Qureshi et al 2016;Menezes et al 2016). Genotoxic effects were also observed in chameleon cichlids Australoheros facetus exposed to imidacloprid (Iturburu et al 2017). …”

Alterations in Some Biochemical Responses of Freshwater Mussels in Acute Imidacloprid Exposure

“…GST protects cells from the deleterious effects of toxic end products of lipid peroxidation. Therefore, increased or unchanged GST activity is considered to be one of the mechanisms that prevent oxidative stress [30]. Similar to the results of this study, Wu et al, reported that imidacloprid induced GST activity in zebrafish embryos [23].…”

Phenotypic, molecular and pathological characterization of motile aeromonads isolated from diseased fishes cultured in Uruguay

“…Acute pathogenicity was determined calculating the lethal dose 50% in 96 hr (LD50 96 ) through the experimental challenge of Australoheros facetus (Pisces: Cichlidae), proceeded from the Instituto de Investigaciones Pesqueras of Universidad de la República (1.5 g of mean body weight). This is a fish species widely distributed in the region and developed in laboratory for use in different types of experimental challenges (Crupkin et al., ; Iturburu et al., ). Five different concentrations (1:10 dilutions from 10 9 CFU/fish) of bacterial suspensions in sterile PBS were evaluated by intraperitoneal injection of 10 μl.g‐1 of body weight.…”