| limb malformations and abnormal sex hormone concentrations in frogs. | declines in amphibian populations, and amphibians with gross malformations, have prompted concern regarding the biological status of many anuran species. a survey of bullfrogs, rana catesbeiana, and green frogs, rana clamitans, conducted in central and southern new hampshire showed malformed frogs at 81% of the sites sampled (13 of 16 sites). brain gonadotropin-releasing hormone (gnrh) and the synthesis of androgens and estradiol, hormones essential to reproductive processes, were measured from ... | 2000 | 11102301 |