Is reproduction of the snail Physella acuta affected by endocrine disrupting compounds? An in situ bioassay in three Iberian basins.

An in situ bioassay was conducted in three Iberian basins (Ebro, Llobregat and Júcar Rivers) to study the reproductive effects on the freshwater snail Physella acuta. Adult individuals were transplanted in specially designed cylindrical cages. Endpoints included mortality, number of eggs and clutches, number of eggs per clutch and embryo development after 8 days. The results were contrasted with laboratory controls. Significant changes in P. acuta reproduction parameters were detected in all of the rivers: the number of clutches or eggs per snail decreased in the Ebro and Llobregat basins downstream but the number of eggs per clutch increased. The complete development of snails was delayed at some sites downstream in the Júcar and the Ebro basins. The results were contrasted with concentrations of Endocrine Disrupting Compounds (EDCs) and their Estrogenic Equivalent Quotients (EEQs). Positive relationships (Pearson correlations) were identified between the number of eggs per clutch and the total EDC concentration, bisphenol A (BPA) and their EEQs, lipid regulators and diuretics. These endocrine-disrupting chemicals may constitute a toxicological risk for the reproductive performance of snails in the studied basins.