One Bd-resistant species is the African clawed frog (Xenopus laevis). About a decade ago scientists suspected that this particular species may have served as a carrier, and facilitated the spread of chytridiomycosis, when they found Bd in a museum specimen dating back to 1934.
[A] new analysis now links the spread of the fungus in the U.S. with the spread of X. laevis, which initially began in the early 1900s. Doctors discovered that the African clawed frog could also be used as a pregnancy test, further increasing the number of frogs imported.
The pregnancy test worked by injecting a woman’s urine under the skin of a female frog. If the woman was actually pregnant, her hormones would stimulate ovulation in the frog.