It’s a strange yet life-saving adaptation…

By Daniel Graham

Published: Wednesday, 25 September 2024 at 14:13 PM


Scientists have discovered that the tadpoles of the Eiffinger’s tree frog (Kurixalus eiffingeri) have learnt not to defecate during the early stages of their development.

Why? It’s all to do with waste management, say researchers in a new study published in the journal Ecology.

An Eiffinger’s tree frog sits with its young in a small pool of water. Credit: Bun Ito

Eiffinger’s tree frogs live on the islands of Ishigaki and Iriomote in Japan. They raise their young in small, isolated water bodies, such as tree hollows and bamboo stumps, away from prying predators.

But these little, hard-to-reach pools present the frog and its tadpoles with a problem. Most other species that excrete toxic ammonia in their faeces live in larger water bodies, where it is readily diluted and therefore harmless. But for the Eiffinger’s tree frog, excessive defecation in their confined pools causes ammonia to build up rapidly, leading to toxicity and endangering their survival.

Fortunately, the tree frog has evolved a rather ingenious strategy for managing its waste: it goes for months without pooping, says Bun Ito, a special research student and Professor Yasukazu Okada at Nagoya University in Japan.

Instead of releasing waste into their environment, Eiffinger’s tree frog tadpoles store ammonia in their intestines, accumulating high concentrations within their bodies, Ito explains.

The frogs only begin to defecate once they transition from tadpoles to subadults, when their waste can be safely expelled outside their spawning site.

Eiffinger’s tree frogs aren’t the only animals to display this sanitation strategy. Some bee and ant larvae are also known to retain faeces in their intestines to keep their homes clean and toxin free.

The research team also found that the frogs have developed a high tolerance to the ammonia, offering further resistance to potential poisoning.

The study offers valuable insights into the unique survival strategies of organisms living in specialised environments.

“The discovery of frogs that have successfully adapted to the unique environment of small water holes reveals a more complex ecosystem within these tiny habitats than we initially imagined,” says Ito.

“Protecting biodiversity necessitates the preservation of these microhabitats.”

Read more about the study: Phytotelmata-dwelling frog larvae might exhibit no defecation: A unique adaptation to a closed aquatic environment

Main image: Iriomote-Ishigaki National Park, Japan. Credit: Getty

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