Frog gives birth to tadpoles as a first in the scientific world
LONDON: For the first time ever, scientists have found a frog that gave birth to tadpoles.
Nearly all the world's 6,000 frog species lay eggs but new born tadpoles are a first in the scientific world.
An international team of researchers followed this unique species of fanged frogs from the Sulawesi Island in Indonesia for over a decade.
On Thursday, they announced the first ever evidence confirming external fertilisation in frogs - the female lays eggs during mating while the male releases sperm to fertilise them.
University of California, Berkeley, herpetologist Jim McGuire was slogging through the rain forests of Indonesia's Sulawesi Island one night this year 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 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."
Frogs have evolved an amazing variety of reproductive methods, says McGuire.
Most male frogs fertilize eggs after the female lays them.
Fanged frogs - so-called because of two fang-like projections from the lower jaw that are used in fighting - may have evolved into as many as 25 species on Sulawesi.
The new species seems to prefer to give birth to tadpoles in small pools or seeps located away from streams, possibly to avoid the heftier fanged frogs hanging out around the stream. There is some evidence the males may also guard the tadpoles.
McGuire first encountered the newly described frog in 1998, the year he began studying the amazing diversity of reptiles and amphibians on Sulawesi, an Indonesian island east of Borneo and south of the Philippines.
LONDON: For the first time ever, scientists have found a frog that gave birth to tadpoles. Nearly all the world's 6,000 frog species lay eggs but new born tadpoles are a first in the scientific world.
An international team of researchers followed this unique species of fanged frogs from the Sulawesi Island in Indonesia for over a decade.
On Thursday, they announced the first ever evidence confirming external fertilisation in frogs - the female lays eggs during mating while the male releases sperm to fertilise them.
University of California, Berkeley, herpetologist Jim McGuire was slogging through the rain forests of Indonesia's Sulawesi Island one night this year 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 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."
Frogs have evolved an amazing variety of reproductive methods, says McGuire.
Most male frogs fertilize eggs after the female lays them.
Fanged frogs - so-called because of two fang-like projections from the lower jaw that are used in fighting - may have evolved into as many as 25 species on Sulawesi.
The new species seems to prefer to give birth to tadpoles in small pools or seeps located away from streams, possibly to avoid the heftier fanged frogs hanging out around the stream. There is some evidence the males may also guard the tadpoles.
McGuire first encountered the newly described frog in 1998, the year he began studying the amazing diversity of reptiles and amphibians on Sulawesi, an Indonesian island east of Borneo and south of the Philippines.
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