Imazapyr+imazapic herbicide determines acute toxicity in silver catfish Rhamdia quelen

• Published in: Ecotoxicology and environmental safety 2016-06, Vol.128, p.91-99
• Main Authors: Golombieski, Jaqueline Ineu, Sutili, Fernando Jonas, Salbego, Joseânia, Seben, Débora, Gressler, Luciane Tourem, da Cunha, Jéssyka Arruda, Gressler, Leticia Trevisan, Zanella, Renato, de Almeida Vaucher, Rodrigo, Marchesan, Enio, Baldisserotto, Bernardo
• Format: Article
• Language: English
• Subjects: AChE; Animals; Aspartate Aminotransferases - blood; ATPases; Blood cells; Blood Glucose - analysis; Catfishes - blood; Catfishes - immunology; Catfishes - metabolism; Cortisol; Gills - drug effects; Gills - immunology; Gills - metabolism; Herbicides - analysis; Herbicides - toxicity; Imidazoles - analysis; Imidazoles - toxicity; Immunity, Innate - drug effects; Muscles - drug effects; Muscles - immunology; Muscles - metabolism; Natural immunity; Niacin - analogs & derivatives; Niacin - analysis; Niacin - toxicity; Nicotinic Acids - analysis; Nicotinic Acids - toxicity; Plasma ions; Potassium - blood; Rhamdia quelen; Sodium - blood; Toxicity Tests, Acute; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - toxicity
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2016.02.010

Imazapyr (IMY) and imazapic (IMI) are imidazolinone herbicides which have been associated in a commercial formulation (Kifix®). To date, there are no studies on the toxicity of an IMY+IMI herbicide in fish. This work aimed to assess the acute toxicity (24 and 96h) of IMY+IMI (0, 0.488 and 4.88µg/L) towards Rhamdia quelen through hematological, biochemical, immunological, ionoregulatory and enzymatic indexes. Red blood cell count was lower at 4.88 than at 0.488µg/L (24 and 96h); mean corpuscular volume was lower than control at both concentrations (24h) and at 0.488µg/L (96h); lymphocytes declined at 4.88µg/L comparing to control (96h); and monocytes increased at 4.88µg/L (96h) in comparison with the respective control and with 4.88µg/L at 24h. Aspartate aminotransferase was higher at 0.488µg/L (96h) than the respective control and the respective concentration at 24h; uric acid reduced at 4.88µg/L comparing with 0.488µg/L (96h); and cortisol was lower at 4.88µg/L compared to 0.488µg/L and control (96h). Herbicide exposure lowered plasma bactericidal activity at both concentrations (24h) and at 0.488µg/L (96h); and plasma complement activity declined at 4.88µg/L comparing with 0.488µg/L and control (96h), and was lower at all concentrations at 96h than at 24h. Plasma K+ levels were higher at 4.88µg/L than in the remaining groups (24 and 96h); and Na+ levels decreased at 4.88µg/L compared to control (96h). Na+/K+-ATPase and H+-ATPase activities in gills were lower at 4.88µg/L comparing with control (24h) and with the respective concentration at 96h; and AChE activity in brain was higher at 0.488 and 4.88µg/L than control (24h) and the respective concentrations at 96h, while in muscle it was higher at 0.488 and 4.88µg/L than control (96h) and the respective concentrations at 24h. The present findings demonstrate that, despite IMY+IMI targets the animal-absent AHAS enzyme, such formulation displayed an acute toxic effect upon R. quelen homeostasis by impacting on vital functions such as immune defense, metabolism, ionoregulation and neurotransmission. •Unprecedented data on imazapyr+imazapic toxicity in fish is shown in Rhamdia quelen.•Hemato-biochemistry, immunity, ionoregulation and neurotransmission were affected.•Imazapyr+imazapic acutely impacts on Rhamdia quelen homeostasis.