Frogs are known for their sticky, whip-like tongues, lumpy warts, and the colorful, poisonous skin covering some species. In Southeast Asia, one group of frogs has another distinguishing feature–fangs. A new species of fanged frog has been discovered that uses their bony jaws jutting out of their lower jawbone to fight with other frogs and hunt shelled prey like giant centipedes and crabs. Limnonectes phyllofolia is the smallest known species of fanged frog and is described in a study published December 20 in the journal PLOS ONE.
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“This new species is tiny compared to other fanged frogs on the island where it was found, about the size of a quarter,” study co-author and biologist Jeff Frederick said in a statement. “Many frogs in this genus are giant, weighing up to two pounds. At the large end, this new species weighs about the same as a dime.” Frederick is a postdoctoral researcher at the Field Museum in Chicago and conducted this research as a doctoral candidate at the University of California, Berkeley.
The frogs were found on the mountainous island of Sulawesi in Indonesia. It’s a large 71,898 square mile-long island with a large network of volcanoes, mountains, lowland rainforest, and cloud forests in the mountains.
“The presence of all these different habitats mean that the magnitude of biodiversity across many plants and animals we find there is unreal—rivaling places like the Amazon,” said Frederick.
Members of a joint United States-Indonesia amphibian and reptile research team noticed something surprising on the leaves of tree saplings and moss-covered boulders in the jungle–frog eggs.
A clutch of Limnonectes phyllofolia eggs laid on a leaf. CREDIT: Sean Reilly
Frogs lay eggs covered by a jelly-like substance instead of a hard and protective shell like a bird. Most amphibians will lay their eggs in water to keep them from drying out, but instead, these frogs left their egg masses on leaves and mossy boulders above the ground. After finding these nests, the team began to see the small, brown frogs.
“Normally when we’re looking for frogs, we’re scanning the margins of stream banks or wading through streams to spot them directly in the water,” Frederick says. “After repeatedly monitoring the nests though, the team started to find attending frogs sitting on leaves hugging their little nests.”
The close contact with the eggs allows the adults to coat them with the right compounds to keep them moist and safe from bacterial and fungal contamination. They were named Limnonectes phyllofolia, which translates to “leaf-nester.”
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The frogs who laid these eggs on leaves and boulders were tiny members of the fanged frog family. The caretakers of the nests were all males.