Effect of Glyphosate on the Development of Pseudosuccinea columella Snails

Abstract.

Glyphosate (Roundup) is one of the most commonly used broad-spectrum herbicides with little to no hazard to animals, man, or the environment. Due to its widespread use, there is continuous contamination of the environment in both soil and water with this herbicide. There is a paucity of long-term exposure studies with sublethal concentrations of glyphosate on aquatic snails. This study was developed to determine the effects of sublethal concentrations of glyphosate on development and survival of Pseudosuccinea columella (intermediate snail host of Fasciola hepatica). This was assessed by continuously exposing three successive generations of snails to varying concentrations (0.1–10 mg/L) of glyphosate. Glyphosate had little effect on the first- and second-generation snails. However, third-generation snail embryos exposed to 1.0 mg/L glyphosate developed much faster than other embryos exposed to 0.1 mg/L, 10 mg/L, and 0 mg/L (control). Hatching was inhibited at 10 mg/L and inhibited slightly at 0.1 mg/L. The egg-laying capacity was increased in snails exposed to 0.1 and 10 mg/L. Abnormalities and polyembryony were observed in snails exposed to 0.1 and 10 mg/L. These results indicate that glyphosate does affect snail reproduction and development. This, in turn, could possibly have an effect on the population dynamics of F. hepatica, which could result in increased infections in animals, including man.