Where do African clawed frogs come from? An analysis of trade in live Xenopis laevis imported in the USA

The African clawed frog, Xenopus laevis, is one of the most widespread and high impact invasive amphibians on earth. The initial purpose of the trade for pregnancy testing saw some hundreds of thousands of animals exported to laboratories throughout the world. Together with the use of this species as the standard laboratory amphibian, it is probably the most widespread amphibian on the planet and has established invasive populations on four continents. Trade figures for imports of live animals into the United States of America suggest that trade for medical and scientific purposes is now minimal (a few hundred animals per year), while the pet trade imports 1.83 million live animals over the last 15 years. Surprisingly, 75% of these animals are imported from Hong Kong. Only 5,600 animals were imported from South Africa, and this trade ceased in 2003. Nearly 200,000 individuals were imported from Chile and the majority of these were reported as being wild caught, suggesting that the invasive population there is being exported for the US pet trade. The implication of large numbers of X. laevis is likely to lead to an increase in the number of invasive populations, as well as movement of individuals that may be carriers of disease, already shown to be present in shipments. Import data for X. laevis into the US suggest that very few African clawed frogs come from Africa, with the vast majority of Asian origin