Acute toxicity of three herbicide formulations of Astyanax altiparanae (Characiformes, Characidae), an emerging neotropical fish model species

ABSTRACT

Herbicides are used in agriculture to control harmful crop weeds, prevent algae proliferation, and enhance macrophyte growth. Herbicide contamination of water bodies might exert toxic effects on fish in different development stages. Sperm, embryos, and adults of Astyanax altiparanae were used as a model to examine the detrimental effects of the following herbicide formulations: Roundup Transorb® (glyphosate), Arsenal® NA (imazapyr), and Reglone® (diquat). The lethal concentration 50 (LC₅₀) values for adults using glyphosate and imazapyr were 3.14 mg/L and 4.59 mg/L, respectively, while the LC₅₀ was higher than 28 mg/L for diquat. For the initial stages of embryo development, LC₅₀ values were 16.52 mg/L glyphosate, 9.33 mg/L imazapyr, and 1084 mg/L diquat. Inhibition of sperm motility was noted at 252 mg/L glyphosate, 137 mg/L imazapyr, and 11,300 mg/L diquat, with an average sperm viability of 12.5%, 73.2%, and 89.3%, respectively, compared to 87.5% detected to control. A. altiparanae exhibited different sensitivities to the herbicide formulations investigated in the developmental stages evaluated. Roundup Transorb® exposure was more toxic for adults, while Arsenal® NA was most harmful for early embryonic development and inhibited sperm motility. Reglone® demonstrated low toxicity for A. altiparanae compared to Roundup Transorb® and Arsenal® NA. A. altiparanae may be considered an emerging fish model for toxicological studies for the neotropical region due to its wide distribution and biological characteristics.

KEYWORDS:

• Glyphosate
• diquat
• imazapyr
• Astyanax altiparanae
• and LC₅₀

Acknowledgments

The authors are grateful to ICMBio/CEPTA for providing the facilities. We thank Roice Eliana Rosim for her support in the HPLC analysis.

Disclosure statement

The authors have no relevant financial or nonfinancial interests to disclose.

Data availability statement

Can be found at the following address: https://10.1080/15287394.2023.2216237.

Additional information

Funding

This work was supported by Metropolitan Water and Energy Company - EMAE (Award Grant: P&D ANEEL PD-0393-0011/2017). Author Dr. José Teixeira Filho has received research support from EMAE.