A newly-discovered frog was witnessed giving birth to live offspring, instead of laying eggs as all other frogs do.
The frog was discovered a few decades ago in Indonesia by researcher Djoko Iskandar. It was suspected to have live births, but the phenomenon had not been observed until now, UC Berkeley reported. The frog is a member of the Asian group of fanged frogs. Dozens of frog species have evolved to fertilize eggs inside of the female's body, but even this mechanism has been poorly understood.
"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," said UC Berkeley herpetologist Jim McGuire, who first witnessed the fascinating birth. "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."
Fanged frogs, named for their sharp "teeth" used in fighting, may have evolved as many as 25 species on the island of Sulawesi, but the new species (Limnonectes larvaepartus) is only the fourth to be described. The new species is believed to prefer to give birth in small pools of water or seeps set away from streams, possibly to avoid larger and more aggressive fanged frog species. There is also evidence that the male frogs guard the newborn tadpoles.
"Sulawesi is an incredible place from the standpoint of species diversity endemic to the island as well as in situ diversification," McGuire said.
The findings were published in a recent edition of the journal PLOS ONE.
