The most abundant series #1: How did the African Claw Frog became the most abundant Amphibians on the planet?

Image source

The short answer is Urine.

The long answer is…..err yeah you know, just read this entry.

Hello fellow Steemians, welcome to my newest 4 part mini-series called The most abundant series! A series where we take a look at some of the most unexpectedly abundant subject (things/animals/molecules) in our planet and possibly beyond that.

Why ’Unexpected’? Because where is the fun in writing things that people can expect?

It’s always more fun (and easier to remember) when it comes to facts that are peculiar, least expected and catches us by surprise; and boy oh boy, you are in for a treat with this one.

FROGS

They’re like slugs; some keep them as pets while some have them for dinner and for the majority of us, we want nothing to do with both of that. Now, Frogs has become so synonymous with the class Amphibia that it’s hard for an average person to name other amphibians than Frogs (Are you struggling as well?) And for good reasons - Frogs are the most abundant Amphibians living among us but if you had to ask which one of them is the most abundant, it would have to be the African Claw Frogs

African Claw Frogs

If you’re asking yourself “Hmm, how come I’ve never heard of such Frog before?”

Chances are, that’s because you weren’t born in the 40’s, and neither was I. Remember I said ’Urine’ at the start of this post? Yeah we’re about to dive into that (Not literally though) so brace yourself teenage boys and girls, you may be looking for these frogs afterwards.

The reason why the population of this Frog boomed circa 1940’s all around the world is because of …………. Pregnancy test.

That’s right, all thanks to a Zoologist named Hogben who was so fascinated with the study of hormones that he began injecting all sort of hormones into different species of frogs (Because hey, what was he supposed to do with all of his free time? How about injecting random hormones into frogs?) It wasn’t until 1927 he moved to South Africa and continued his experiment on local species.

And that was when he stumbled upon the Xenopus sp. (African Claw Frog)

Hogben fell in love with how convenient it was to work with the frog that he named his house after it (True story) It was love at first sight (or injection) for Hogben up to a point that the frog laid eggs for him (Get it? No? I should stop? Okay)

After injecting extracts from an ox’s pituitary gland, he noticed that the frog started laying eggs. At the time, we kind of know that the urine of pregnant women contained hormones that were produced in the pituitary gland which eventually exert effects on the ovaries and ultimately fertility. It wasn’t long before he started using urine of pregnant women to take it a step further and lucky for him, in 12 hours after exposure to the said urine, the frog laid eggs. What’s in the urine? It’s none other than the hormone Beta Human chorionic gonadotropin (B-HCG) which is found in large amount in the urine of pregnant women and the substance responsible for inducing ovulation in the frog.

Image source

This was pretty much a big deal because immediately before that, the pregnancy test used were laborious, bloody and took a relatively long time to yield results as it involved injecting, killing and dissecting mice and rabbits to see the size and morphology of their ovaries after around 5 days.

Because of this, a species that was once native to Africa, saw world domination as they were imported to Europe and the Americas. It became the standard way of diagnosing pregnancy by doctors as urine samples were sent to technician in frog labs to carry out the test and look for the tell-tale frog eggs dotting the water the next morning. Even after pregnancy kit was developed, the frog’s legacy lives on as they can be found in many urban centers and big cities around the world, outside of Africa, thought to be because of their subsequent release into the wild after hospitals no longer had use for them.

But that’s not the only reason why they are abundant

It’s also because of the Frog’s own innate abilities.

1) They can adapt to various habitats, including artificial ones

Although doing best in Mediterranean climate, Xenopus sp. can be found thriving in all sort of different pools and waters of different climates around the world; From the canals in the Netherland, to the artificial ponds in Arizona, California and even the beaver pond in Colarado. This is thanks to fact that they have a wide temperature window where they can tolerate temperature anywhere between 0 to 30 degree Celsius. Given the fact that they are highly salt-tolerant, you can also find them hopping around (Pun intended) near sea cliffs where they are subjected to sea spray.

If that’s not tough enough, even in drought, they can survive prolonged starvation of up to one year and breed like nobody’s business in both acidic and alkaline waters.

2) They eat pretty much everything

From insects, fishes to even chunks of organic waste, this happy hopper has developed a taste for a lot of stuff that even other animals don’t find edible. They even eat birds, other amphibians and get this, resort to cannibalism by consuming its own larvae, meaning to say that even if you deprive them of food, they can make their own. Yes, top that Bear Grylls!

Image source

With that, we have come to the end of this 1st episode, hope you enjoyed this entry and learned something from it. Be sure to follow me for the upcoming episodes and more top quality content. Be sure to check out other posts in my blog. If you fancy on some further reading, check out the references below.

Thank you very much.

References:

1. The Amphibian Pregnancy Test
2. How a Frog Became the First Mainstream Pregnancy Test
3. Introduced Species Summary Project African Clawed Frog (Xenopus laevis)
4. Doctors Used to Use Live African Frogs As Pregnancy Tests