02596naa a2200325 a 450000100080000000500110000800800410001902200140006002400530007410000270012724501060015426000090026052015590026965000350182865000190186365000230188265000290190565000230193465000260195765000190198365300310200265300250203365300280205870000180208670000290210470000260213370000230215970000200218277300680220220025352014-12-15       2014    bl uuuu     u00u1 u    #d  a1676-56807 ahttp://dx.doi.org/10.4238/2014.January.28.62DOI1 aRIVERO-WENDT, C. L. G.  aEffects of 17α-methyltestosterone on the reproduction of the freshwater snail Biomphalaria glabrata.  c2014  a17-α-methyltestosterone (MT) is a synthetic hormone used in fish hatcheries to induce male monosex. Snails hold promise as possible test models to assess chemicals acting on the endocrine system. Biomphalaria glabrata is an aquatic gastropod mollusk (Pulmonata, Planorbidae) that can be easily maintained in aquaria, predisposing the species for use in ecotoxicological testing. This study evaluated the reproductive effects of MT on B. glabrata by examining histological changes and its reproductive performance. Ten snails per group were exposed for 4 weeks to different concentrations of MT (0.01, 0.1, and 1.0 mg/L). The total number of laid eggs, egg mass per group, size of type V oocytes, and production of spermatozoids were determined. Reproduction of B. glabrata was affected by MT. At the lowest concentration (0.01 mg/L), MT caused a statistically significant increase in the number of egg mass per snail compared with controls unexposed to MT. Histopathology analyses showed an increase in the sperm production at the higher MT concentrations of 0.1 and 1.0 mg/L. Chromatographic analyses of water samples showed that MT concentrations rapidly declined within a 96-h period. These results highlight the importance of giving more support to regulatory authorities, since MT is not registered for use on fish hatcheries in many countries around the world. Wastewater from fish farms discharged into aquatic ecosystems should be monitored for MT residues, since its presence could compromise the reproduction of other native snail species.  aEndocrine-disrupting chemicals  aHistopathology  aMethyltestosterone  aReproductive performance  aSynthetic hormones  aBiomphalaria Glabrata  aHistopatologia  aDesreguladores endócrinos  aHormônio sintético  aPerformance reprodutiva1 aBORGES, A. C.1 aOLIVEIRA FILHO, E. C. de1 aMIRANDA-VILELA, A. L.1 aFERREIRA, M. F. N.1 aGRISOLIA, C. K.  tGenetics and Molecular Researchgv. 13, n. 1, p. 605-615, 2014.