In this study, we found many amphibians with bizarre appearances, known as malformations in Pingtung County, southern
Taiwan. For this investigation we collected frogs inhabiting the Kaoping and Tungkang river watersheds between February 2006 and June
2007. Among the total number of 10,909 normal frogs (i.e., anurans) collected during the investigation period, the Indian rice frogs (Rana
limnocharis) account for the greatest number; next is the Chinese bullfrog (Rana rugulosa). Of all the 244 captured malformed frogs, the
Indian rice frog account for the greatest proportion. These malformed frogs have their main distribution in upstream areas of these two
rivers. Our result indicates that the appearance rate of malformed frogs is 1.8% in the upstream reaches of the Kaoping River and 2.6%,
and 0.8%, respectively in the upstream and midstream reaches of the Tungkang river. The most-commonly-found malformation is the lack
of palms, followed by the lack of appendages, exostosis, and a malformed appendicular. It is, therefore, reasonable to speculate that the
causes for the malformation may be related to the increased organic pollutants and agricultural chemicals used in the upstream reaches of
these two rivers.
