Résumé:
Glyphosate (GLY) [N-(phosphonomethyl) glycine] is one of the world's
most widely used agricultural herbicides with the risk of aquatic contamination. In this study, the acute
toxicity of Gly in shrimp Palaemon adspersus (Decapoda, Palaemonidae) was assessed by estimating
sublethal (LC10, LC25) and lethal (LC50, LC90) concentrations after 96-h exposure.
Objectives: In this study, the acute toxicity of Gly in shrimp Palaemon adspersus (Decapoda,
Palaemonidae) was assessed by estimating sublethal (LC10, LC25) and lethal (LC50, LC90) concentrations
after 96-h exposure.
Methods: The compound was added to the rearing water at LC25 and LC50-96h (as determined
previously), and treatments were performed during the exposure phase (24, 48, 72 and 96-h) after which
the shrimp were transferred to clean seawater and collected after the recovery period (24, 48, 72 and
96-h). Enzymatic activities were measured in shrimp heads and flesh fragments to quantify AChE, GST,
and MDA activity, followed by lipid quantification.
Results and discussion: Overall, the toxicity tests showed significant variation (p< 0.05) in P.
adspersus mortality rates, with a dose-response effect. The LC10, LC25, LC50, and LC90 after 96-h of
exposure. During the exposure phase, two-way ANOVA revealed significant effects of Gly
concentration and exposure time on all studied biomarkers.
Conclusion: It presented oxidative stress and neurotoxic effects at sublethal concentrations.
This suggests that they should be carefully controlled to minimise negative impacts on non-target
aquatic organisms.
Keywords: Herbicide, Glyphosate, Shrimp, Toxicity tests, Biomarker
