title: The effects of thiosemicarbazide on development in the wood frog, Rana sylvatica. II. Critical exposure length and age sensitivity.
abstract: Wood frog (Rana sylvatica) tadpoles were exposed to 50 mg thiosemicarbazide (TSC)/liter water for varying lengths of time and at different developmental stages. Short exposure periods (3 and 6 hr) resulted in no visible deformities. Exposure periods of 12 or more hr caused slight to severe abnormalities, with a direct relationship between length of exposure and degree of deformity. Tadpoles exposed to TSC from posthatching Days 24-30 were more seriously affected than were tadpoles exposed at an older age.
mesh_terms: D000375:Aging; D000818:Animals; D011898:Ranidae / Q000254:growth & development*; D012663:Semicarbazides / Q000633:toxicity*; D013723:Teratogens
chemical_list: D012663:Semicarbazides; D013723:Teratogens; C005151:thiosemicarbazide