African Clawed Frog (Xenopus Laevis) (image) San Francisco State University Caption This is an African Clawed Frog (Xenopus Laevis). These frogs, originally imported for early 20th century pregnancy tests, carried a deadly amphibian disease to the US, according to a new study published in the journal PLOS ONE. San Francisco State University biologist Vance Vredenburg and colleagues have found the first evidence of the Batrachochytrium dendrobatidis fungus among introduced feral populations in the US. Credit Photo credit: Adam Bewick Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.