Acute toxicity and cholinesterase inhibition of the nematicide ethoprophos in larvae of gar Atractosteus tropicus (Semionotiformes: Lepisosteidae)

Abstract

Biomarkers are a widely applied approach in environmental studies. Analyses of cholinesterase (ChE), glutathione S-transferase (GST) and lipid peroxidation (LPO) are biomarkers that can provide information regarding early effects of pollutants at different biochemical levels on an organism. The aim of this study was to evaluate the biomarker approach on a Costa Rican native and relevant species. For this, larvae of gar (Atractosteus tropicus) were exposed to the organophosphorus nematicide, ethoprophos. Acute (96hr) exposure was conducted with pesticide concentrations ranging from 0.1μg/L to 1 500μg/L. The 96hr LC50 calculated was 859.7μg/L. After exposure, three biomarkers (ChE, GST and LPO) were analyzed in fish that survived the acute test. The lowest observed effect concentration (LOEC) regarding ChE activity inhibition was 50μg/L. This concentration produced a significant inhibition (p0.05) in GST activity and LPO were observed in A. tropicus larvae after exposure to ethoprophos.

Keywords

• gaspar
• Atractosteus tropicus
• etoprofos
• inhibidores de la colinesterasa
• glutatión S-transferasa
• peroxidación lipídica