Sensitivity of New Zealand mudsnail Potamopyrgus antipodarum (Gray) to a specific aromatase inhibitor

The freshwater prosobranch Potamopyrgus antipodarum (Molluska, Hydrobiidea, Smith 1889) has been proposed as a suitable species to assess the impact of endocrine disrupting compounds (EDC) in aquatic ecosystems. Steroid hormone biosynthesis pathway is potentially an important target for EDC, and vertebrate-like sex steroids seem to play a functional role in the control of mollusk reproduction. To assess the response and the sensitivity of A antipodarum to disrupters of the steroid hormone biosynthesis pathway, we have experienced the action of a specific vertebrate aromatase inhibitor, fadrozole, acting on 17 beta-estradiol synthesis in two separate 28 and 42 d exposures. Fadrozole had effects consistent with the expected mechanism of action. A decrease of the reproduction parameters (such as on the number of neonates and number of embryos in the brood pouch) in a dose-dependant manner was observed. The steroids levels were also impaired with the ratio 17 beta-estradiol/testosterone decreased by half in exposed snails. This shift of the steroids balance was accompanied by some alteration in the gonads histology and immunohistochemistry in fadrozole-exposed snails. This study highlights the value role of A antipodarum as a test species for assessing EDC effects in aquatic wildlife. (C) 2010 Elsevier Ltd. All rights reserved.