Gastric Brooding Frog

Northern Gastric Brooding Frog; now extinct. Photo by M. Davies.

I really hate to start off the amphibian section of this blog with a bittersweet story, but at the moment it seems that all amphibian stories are heading that way, as there is a huge decline in their numbers around the world.  But these amazing frog species, the gastric brooding frogs, were my favorite amphibians, and they went extinct in my life time, just a few short years after they were discovered.

Why did I love them so much?  Well, what they are most remembered for is also what they got their common name from, and that is their amazing reproductive strategy.  When these frogs laid their eggs, the digestive acids in their stomachs would shut off and they would swallow their own eggs.  There the eggs would sit until they hatched, and the tadpoles would never see the light of day.  Instead, they completely developed into little froglets while still inside their mother’s stomach and to give birth, the mother would dilate her esophagus and 18-25 little froglets would jump out of her mouth, one at a time!

Gastric brooding frog and froglet

Gastric brooding frog with froglet emerging from its mouth. Photo by Mike Tyler

If that’s not cool, I don’t know what is.  In this way, the frog kept its eggs safe at the expense of not being able to eat for 6 to 7 weeks while the young were developing.

One interesting aspect of these frogs’ mysterious solution to egg predation is how they managed to shut off their stomach acid.  It appears that the digestive acids shut down because of chemicals being secreted by the egg jelly and the tadpoles.  Why is that important?  Because scientists thought that maybe this chemical held the secret to a fantastic ulcer treatment.  Unfortunately they never found out, nor will they ever find out.  And I will never be able to see my favorite frog in real life.

The University of Michigan has some great further reading on their Animal Diversity Web site.  Please note that the first picture in this blog is the northern gastric brooding frog, while much of the research and information provided here was about the southern gastric brooding frog.

If you are interested in why amphibian populations are declining world wide and what you can do to help, please check out Save the Frogs to learn more.  This is a fantastic organization focusing on education and research to help protect amphibians.

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