Stomach tadpoles

Remember those fish that raise their children inside their mouths? Two Australian frog species went even further: they raised tadpoles in their stomachs.

At the start of this month I wrote about cuckoo fish. I was particularly weirded out by the fact that some fish incubate their young inside their mouths – and that other fish swapped them with their own young to have them raised by the poor mother fish. Well, thanks to a young reader, I’ve learned about something that’s even weirder.

The platypus frogs, also known as the gastric-brooding frogs, of eastern Australia are that something weirder. The female lays eggs; the male fertilizes the eggs; then the female eats the eggs.

Fortunately, these eggs are special: they’re coated in a jelly that inhibits the production of stomach acid. So they sit in the frog’s stomach until they hatch. And then the tadpoles produce the same acid-inhibiting substance! They stay inside for up to six weeks and then get vomited / born into the world at large.

A similar frog in Chile – Darwin’s frog, discovered by the man himself – raises its young inside its vocal sac. But somehow, raising tadpoles in your actual literal stomach is more impressive.

The gastric-brooding frog, alas, became extinct about thirty years ago – another victim of habitat destruction and disease. There are efforts underway to bring it back to life through cloning. I wonder how they’ll manage the stomach-brooding part?

[Thanks to Ma’a P. for suggesting this topic.]

• Gastric-brooding frog
• Darwin’s frog