LAUSR

Roundup® is the most used glyphosate-based herbicide. During agricultural use it may directly contaminate existing aquatic ecosystems, posing severe concerns for the safety of non-target terrestrial and aquatic organisms. We investigated the outcome of exposure to different concentrations of glyphosate in Roundup® on cyst hatchability, toxicity, and teratogenic effects in the aquatic crustacean Artemia salina (A. salina) that inhabits diverse types of salt waters and, as a filter feeder, carries a greater risk of being exposed to pollutants. We found that exposure to 144 and 288 μg/mL glyphosate in Roundup® resulted in cysts unable to complete diapause, and hatchability was completely inhibited during all exposure times tested (17 h- 48 h). Glyphosate concentrations of 288 μg/mL in Roundup® was lethal to A. salina nauplii and the lower concentrations (9, 18, 36, 72 μg/mL) had no significant effects on viability. In addition, sublethal and environmentally safe concentrations of glyphosate (0.72 μg/mL) in Roundup® also affected the early development of A. salina nauplii, with significantly decreased body lengths and reduced widths of the tail, abdomen and head. The increased level of catalase activity observed in nauplii exposed to 0.72 μg/mL glyphosate for 24 h and those exposed to 7.2 and 72 μg/mL glyphosate for 48 h may be linked to excessive ROS levels that had been induced by Roundup®. In conclusion, Roundup® containing greater than 72 μg/mL glyphosate totally inhibited hatching of cysts and exerted toxic effects on A. salina nauplii. The increased prevalence of developmental defects in the nauplii observed at 0.72 μg/mL glyphosate, signifies possible teratogenicity of Roundup® exposure even at concentrations of glyphosate, possibly due to disturbance of the antioxidant defenses, which needs further investigation.