Short-term effects of pesticide fipronil on behavioral and physiological endpoints of Daphnia magna

Adam Bownik,Aleksandra Szabelak

doi:10.1007/s11356-021-13091-6

Adam Bownik, Aleksandra Szabelak

Open Access

https://doi.org/10.1007/s11356-021-13091-6

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Abstract

Fipronil (FIP) is an organic pesticide with many practical uses. Although some results indicated toxic effects in some terrestrial and aquatic animal species, little is known on its influence on behavioral and physiological endpoints of cladocerans. The aim of our study was to determine the short-term effects of FIP at concentrations of 0.1 μg/L, 1 μg/L, 10 μg/L, and 100 μg/L on Daphnia magna sublethal indices: behavioral (swimming speed, distance traveled) and physiological endpoints (heart rate, post-abdominal claw activity and thoracic limb movements). The results showed that FIP induced reduction of swimming speed and distance traveled in a concentration- and time-dependent manner at all the concentrations used. The lowest concentration of the insecticide temporarily stimulated post-abdominal claw activity after 24 h and thoracic limb activity after 48 h; however, the highest concentrations reduced all the studied physiological endpoints. IC50 values showed that thoracic limb activity, swimming speed, and distance traveled were most sensitive to FIP after 24-h exposure. The most sensitive parameter after 48 h and 72 h was swimming speed and post-abdominal claw activity, respectively. The study indicated that (i) behavioral and physiological endpoints of Daphnia magna are reliable and valuable sublethal indicators of toxic alterations induced by FIP; however, they respond with different sensitivity at various times of exposure, (ii) FIP may alter cladoceran behavior and physiological processes at concentrations detected in the aquatic environment; therefore, it should be considered as an ecotoxicological hazard to freshwater cladocerans.

Highlights

Fipronil (FIP), a derivative of phenylpyrazole, is one of the most widely used organic pesticides in agriculture, veterinary medicine, and urban households for selective elimination of insect pests such as ants, mosquitos, termites, cockroaches, spiders, fleas, and mites (Tomlin 1994; Aajoud et al 2003; Scarampella et al 2005; Gunasekara et al 2007; MacLachlan 2008; Simon-Delso 2014; Ardeshir et al 2017; Rust 2017)
Post-abdominal claw activity, and thoracic limb movement were determined by a microscopic method supported by previously described digital video analysis (Campbell et al 2004; Bownik et al 2019a, b, 2020b)
Individual daphnids were gently transferred with a Pasteur pipette in about 50-μL drop from each experimental Petri dish or the control group to a microscope slide for the Calculation of nominal IC50 of the studied endpoints revealed that the most sensitive endpoints after 24-h exposure to FIP were thoracic limb activity (IC50 = 2.8 ± 0.7 μg/L) (Table 1; Fig. 1), swimming speed (3.5 ± 0.2 μg/L), and distance traveled (3.3 ± 0.2 μg/L)

Summary

Introduction

Fipronil (FIP), a derivative of phenylpyrazole, is one of the most widely used organic pesticides in agriculture, veterinary medicine, and urban households for selective elimination of insect pests such as ants, mosquitos, termites, cockroaches, spiders, fleas, and mites (Tomlin 1994; Aajoud et al 2003; Scarampella et al 2005; Gunasekara et al 2007; MacLachlan 2008; Simon-Delso 2014; Ardeshir et al 2017; Rust 2017). The presence of FIP in food is especially important for human health as this pesticide was classified by the US EPA as a group C (possible human) carcinogen (Charalampous et al 2019).

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