University of California, Berkeley, herpetologist Jim McGuire was slogging through the rain forests of Indonesia's Sulawesi Island one night this past summer when he grabbed what he thought was a male frog and found himself juggling not only a frog but also dozens of slippery, newborn tadpoles.
He had found what he was looking for: direct proof that the female of a new species of frog does what no other frog does. It gives birth to live tadpoles instead of laying eggs.
A member of the Asian group of fanged frogs, the new species was discovered a few decades ago by Indonesian researcher Djoko Iskandar, McGuire's colleague, and was thought to give direct birth to tadpoles, though the frog's mating and an actual birth had never been observed before.
"Almost all frogs in the world - more than 6,000 species - have external fertilization, where the male grips the female in amplexus and releases sperm as the eggs are released by the female," McGuire said. "But there are lots of weird modifications to this standard mode of mating. This new frog is one of only 10 or 12 species that has evolved internal fertilization, and of those, it is the only one that gives birth to tadpoles as opposed to froglets or laying fertilized eggs."
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