One-line, two-line, the linear outcome of the fertility pee-stick we now find in all of our major drug stores. But these fifteen-minute, life-altering hormonal tests weren’t always the go-to precursor to pregnancy; in fact, they simply didn’t until the late 70’s.[vc_row][vc_column width=”2/3″][text_output]But the amphibian taxa is croaking with solutions. A decade before the drug store staple, female African clawed frogs (Xenopus laevis) were placed in solutions that contained a questioning or soon-to-be mother’s urine. And, if the female frogs began to show signs of ovulation, the resulting dialogue was often, “you’re pregnant!” Clever, isn’t it? It’s a shame then that the test animals had unknowingly fertilized an amphibious epidemic as well.

From Across the Preverbal Pond

African clawed frogs, as you could decipher from their common name, aren’t endemic to the shallow ponds of North America—they’re not even found in the Western hemisphere. They do, however, flourish in the pound and riparian-like environments of Sub-Saharan Africa, laying eggs from late-winter to early-spring. And with males averaging about twenty-percent smaller than their voluptuous female mates, sexual dimorphism is all too evident in mature adult frogs; young froglets are capable of maturing to full-grown, fertile adults within ten-months of metamorphism. That’s “lickety-split,” to say the least—no pun intended. Well, I’d be lying if I said I didn’t intend to quip the former—but I digress. And, for nearly two-decades, they’ll continue to spawn in those very same hydrophilic realms.

Clawing Their Way To Invasive Freedom

Because of their affinity—and accuracy, for that matter—at detecting human pregnancies, African clawed frogs were imported by the tens-of-thousands in the 60’s, prior to the homologation of the now staple pregnancy tests. The frogs represented a booming practice; no estrogen-laden lily pad seemed too expansive to leapfrog over. Granted, that hyperbole’s said in the complete hypothetical; African clawed frogs are completely aquatic, after all. But those lily pads lost their inherent bouncy in the late 90’s. By this time, the quirky frogs represented an antiquated, laborious fertility practice. Why have your urine exposed to a control group of female frogs when the drug store’s a five-minute drive away? Needless to say, the latter proved to be more appealing. And, whether by a sly of hand or accidental introduction, these frogs later found themselves in an alien Atlantis—a Californian man-made pond. These asymptomatic vectors of chytridiomycosis—and subsequent carriers of the fungus responsible for the disease, Batrachochytrium dendrobatidis—were not only found in the state’s waterways, but later tested positive for the fungus. And, like adding gasoline to an already pluming ecological fireball, the frogs proved to carry a more virulent strain of the fungus as well.

Unlike the pregnancy tests they inspired, their introduction to North America’s aquatic niches isn’t a simple linear expression—it’s a blurred line, at best. As we all know, eradicating an invasive species is a daunting, often futile endeavor. The likely solutions to the problem are analogous to placing a bandage on a gunshot wound—they’re mitigatory. Lesson learned: keep the “whoopee test” out of the anuran complex. It’ll save you a trip to the urinal too.

By Matt Charnock[/text_output][/vc_column][vc_column width=”1/3″][text_output]These hardy, tolerant frogs later assimilated themselves into the exotic pet trade. The Albino clawed frogs, pictured above, exemplify the “pretty and cute” pet mantra that’s all too appealing to the everyday consumer; owner accounts citing the release of their now bored of pets into the wild are quite common. Photo © Liz West[/text_output][gap size=”1.313em”]

[text_output]African clawed frogs (Xenopus laevis) are the only amphibians to possess true claws, utilizing their dexterous appendages to climb submerged obstacles and tear apart prey items. Photo ©  Brian Gratwicke[/text_output][/vc_column][/vc_row]

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