There are over 6,000 frog species in the world and almost all of them are known to spawn or lay eggs that later develop into tadpoles and them metamorphose into froglets – with a few exceptions of course – but researchers from the University of California in Berkeley have discovered a new species of Asian Fanged frog that gives birth to live tadpoles directly.
Known as Limnonectes larvaepartus and first discovered decades ago by an Indonesian researcher, Djoko Iskandar, researchers had never really seen this particular frog mate or spawn eggs firsthand. But Jim McGuire, a herpetologist from UC chanced upon this frog one night in the rainforests of Sulawesi Island in eastern Indonesia – and found that it was actually a female with about a dozen slippery, new tadpoles with her.
According to McGuire, “Almost all frogs in the world — more than 6,000 species — have external fertilization, where the male grips the female in amplexus (the frog mating embrace) and releases sperm as the eggs are released by the female. 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.”
Frogs all over the world are known to have very unusual behaviors and characteristics when it comes to creating offsprings. For instance, some species of frogs in Africa are known to engage in internal fertilization and give birth to live froglets that never go through the tadpole stage. Some are even known to “carry eggs in pouches on their back, brood tadpoles in their vocal sac or mouth, or transport tadpoles in pits on their back.”
Two extinct female gastric brooding frogs are “famous for swallowing their fertilized eggs, brooding them in their stomach, and giving birth out of their mouths to froglets,” and this is just one of many weird aspects of frogs as well as other animals out there in the rainforests and in deep waters.