Cardiac and neurobehavioral impairments in three phylogenetically distant aquatic model organisms exposed to environmentally relevant concentrations of boscalid

• Published in: Environmental pollution (1987) 2024-04, Vol.347, p.123685-123685, Article 123685
• Main Authors: Bedrossiantz, Juliette, Goyenechea, Júlia, Prats, Eva, Gómez-Canela, Cristián, Barata, Carlos, Raldúa, Demetrio, Cachot, Jérôme
• Format: Article
• Language: English
• Subjects: Animals; Aquatic Organisms; Behavior; Biodiversity and Ecology; Biphenyl Compounds; Daphnia; Earth Sciences; Ecosystem; Ecotoxicology; Environmental Sciences; Environmental toxicology; Fungicide; Fungicides, Industrial - metabolism; Heart rate; Life Sciences; Niacinamide - analogs & derivatives; Niacinamide - toxicity; Oceanography; Sciences of the Universe; Succinate dehydrogenase inhibitor; Toxicology; Water Pollutants, Chemical - metabolism; Zebrafish - metabolism
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2024.123685

Boscalid (2-Chloro-N-(4′-chlorobiphenyl-2-yl) nicotinamide), a pyridine carboxamide fungicide, is an inhibitor of the complex II of the respiration chain in fungal mitochondria. As boscalid is only moderately toxic for aquatic organisms (LC50 > 1–10 mg/L), current environmental levels of this compound in aquatic ecosystems, in the range of ng/L-μg/L, are considered safe for aquatic organisms. In this study, we have exposed zebrafish (Danio rerio), Japanese medaka (Oryzias latipes) and Daphnia magna to a range of concentrations of boscalid (1–1000 μg/L) for 24 h, and the effects on heart rate (HR), basal locomotor activity (BLA), visual motor response (VMR), startle response (SR), and habituation (HB) to a series of vibrational or light stimuli have been evaluated. Moreover, changes in the profile of the main neurotransmitters have been determined. Boscalid altered HR in a concentration-dependent manner, leading to a positive or negative chronotropic effect in fish and D. magna, respectively. While boscalid decreased BLA and increased VMR in Daphnia, these behaviors were not altered in fish. For SR and HB, the response was more species- and concentration-specific, with Daphnia exhibiting the highest sensitivity. At the neurotransmission level, boscalid exposure decreased the levels of L-aspartic acid in fish larvae and increased the levels of dopaminergic metabolites in D. magna. Our study demonstrates that exposure to environmental levels of boscalid alters cardiac activity, impairs ecologically relevant behaviors, and leads to changes in different neurotransmitter systems in phylogenetically distinct vertebrate and invertebrate models. Thus, the results presented emphasize the need to review the current regulation of this fungicide. [Display omitted] •A chronotropic effect of boscalid on heart rate was observed after 24h-exposure.•Exposure to 10 μg/L boscalid elicits different startle responses in fish larvae.•D. magna was the most sensitive organism to the effect of boscalid on habituation.•A significant decrease in aspartate concentrations was observed in both fish species.•Dopaminergic, GABAergic and histaminergic metabolite levels were altered in D. magna.