Kalimantan find is only the 4th creature with backbones known to breathe without lungs
Shobana Kesava, Straits Times 10 Apr 08;
SINGAPORE scientists have discovered a lungless frog that breathes through its skin - a find that makes evolutionary history.
The aquatic frog is affectionately called Barbie - short for its scientific name Barbourula kalimantanensis. It was found in two mountain rivers in the heart of Kalimantan last August.http://www.blogger.com/post-edit.g?blogID=4322865532175731446&postID=8255826818945290547
A group of nine researchers, led by evolutionary biologist David Bickford from the National University of Singapore (NUS), found the flat, dark brown frogs with golden specks under smooth rocks in clean, cool and fast-flowing water.
Their findings are set to be published next month.
Since animals first waddled onto land eons ago, only three other creatures with backbones - two groups of salamanders and a single species of the earthworm-like caecilians - have been known to forsake their lungs.
Dr Bickford, 39, said Barbie absorbs oxygen dissolved in the water through its skin.
'The discovery is not so much a surprise to the scientific community as much as a surprise that it has taken so long to find it,' DrBickford said.
One reason could be that the frog resides deep in mountain rivers and is fully aquatic.
A fisherman first took a Barbie to Indonesian scientist Djoko Iskandar in Kalimantan in 1978. He had been searching for the animal ever since.
Part of the NUS team last August, DrDjoko co-authored the scientific paper with DrBickford.
'Djoko was near tears when we found them after all those years of searching,' said DrBickford.
The specimens the NUS team discovered were well over 50km from where the first frogs were spotted by local fishermen.
Their original wading grounds had become prime gold-mining and logging territory.
'They must have been forced upstream from their original habitats...so we got to the end of the logging road and started the search,' added DrBickford.
He hopes the find will help spur research into South-east Asian wildlife, much of which is threatened by development.
'Frogs are a clear indication of how degraded our environment is, so if people who know the terrain can help us discover what we have and preserve it, my work in conservation will be worth it,' he said.
Indonesian zoologist Indraneil Das, who studies amphibians and reptiles, said the discovery of a lungless frog could stir up national interest.
'This shows us yet another innovation by amphibians. If the findings are read by the government and if it does something about them by way of conservation...that will be a good thing for all concerned, except perhaps the gold-miners.'
Frog without lungs found in Indonesia
Michael Casey, Associated Press Yahoo News 10 Apr 08;
A frog has been found in a remote part of Indonesia that has no lungs and breathes through its skin, a discovery that researchers said Thursday could provide insight into what drives evolution in certain species.
The aquatic frog Barbourula kalimantanensis was found in a remote part of Indonesia's Kalimantan province on Borneo island during an expedition in August 2007, said David Bickford, an evolutionary biologist at the National University of Singapore. Bickford was part of the trip and co-authored a paper on the find that appeared in this week's edition of the peer-reviewed journal Current Biology.
Bickford said the species is the first frog known to science without lungs and joins a short list of amphibians with this unusual trait, including a few species of salamanders and a wormlike creature known as a caecilian.
"These are about the most ancient and bizarre frogs you can get on the planet," Bickford said of the brown amphibian with bulging eyes and a tendency to flatten itself as it glides across the water.
"They are like a squished version of Jabba the Hutt," he said, referring to the character from Star Wars. "They are flat and have eyes that float above the water. They have skin flaps coming off their arms and legs."
Bickford's Indonesian colleague, Djoko Iskandar, first came across the frog 30 years ago and has been searching for it ever since. He didn't know the frog was lungless until they cut eight of the specimens open in the lab.
Graeme Gillespie, director of conservation and science at Zoos Victoria in Australia, called the frog "evolutionarily unique." He said the eight specimens examined in the lab showed the lunglessness was consistent with the species and not "a freak of nature." Gillespie was not a member of the expedition or the research team.
Bickford surmised that the frog had evolved to adapt to its difficult surroundings, in which it has to navigate cold, rapidly moving streams that are rich in oxygen.
"It's an extreme adaptation that was probably brought about by these fast-moving streams," Bickford said, adding that it probably needed to reduce its buoyancy in order to keep from being swept down the mountainous rivers.
He said the frog could help scientists understand the environmental factors that contribute to "extreme evolutionary change" since its closest relative in the Philippines and other frogs have lungs.
Bickford and Gillespie said the frog's discovery adds urgency to the need to protect its river habitat, which in recent years has become polluted due to widespread illegal logging and gold mining. Once-pristine waters are now brown and clogged with silt, they said.
"The gold mining is completely illegal and small scale. But when there are thousands of them on the river, it really has a huge impact," Bickford said. "Pretty soon the frogs will run out of the river.
Lungless frog discovered in Borneo
Yahoo News 9 Apr 08;
A rare and primitive frog living in a remote Borneo stream has no lungs and apparently absorbs oxygen through its skin, researchers reported on Wednesday.
The aquatic frog has evolved backwards, re-acquiring a primordial trait, David Bickford of the National University of Singapore and colleagues reported.
Studying the frog could help shed light on how lungs evolved in the first place, they wrote in the journal Current Biology, adding that illegal gold mining in the area may threaten the unique species.
"The evolution of lunglessness in tetrapods (amphibians, reptiles, birds, and mammals) is exceedingly rare, previously known only from amphibians -- two families of salamanders and a single species of caecilian (blindworm)," they wrote.
"Here we report the first case of complete lunglessness in a frog, Barbourula kalimantanensis, from the Indonesian portion of Borneo."
The frog may be endangered because of mining activity, the researchers said.
"In August 2007, we visited ... near NangaPinoh, Western Kalimantan but found that illegal gold mining had destroyed all suitable habitats in the vicinity," they wrote. They snorkeled, waded and turned over boulders to find their quarry.
"The originally cool, clear, fast-flowing rivers are now warm and turbid. Water quality around the ... locality is no longer suitable for the species, but we were able to re-discover two new populations upstream," they added.
"We knew that we would have to be very lucky just to find the frog," Bickford said in a statement.
Animals evolved lungs when they moved from the sea to land millions of years ago. Animals have only lost this important adaptation a few times, Bickford's team said.
"The discovery of lunglessness in a secretive Bornean frog, supports the idea that lungs are a malleable trait in the Amphibia, the sister group of all living tetrapods. Amphibians maybe more prone to lunglessness since they readily utilize other methods for gas exchange," they wrote.
"This is an endangered frog that we know practically nothing about, with an amazing ability to breathe entirely through its skin, whose future is being destroyed by illegal gold mining by people who are marginalized and have no other means of supporting themselves," Bickford said.
Only animals with small body sizes, slow metabolisms and living in fast-flowing cold water where oxygen and carbon dioxide are exchanged quickly may be able to survive without lungs, the researchers said.
"We strongly encourage conservation of remaining habitats of this species," they recommended.
(Reporting by Maggie Fox; Editing by Cynthia Osterman)
Lungless frog could shed light on evolution: scientist
Aubrey Belford, Yahoo News 11 Apr 08;
The discovery of a rare species of Indonesian frog that breathes without lungs could shed light on how evolution works, a scientist said Friday.
Dissection of the frog, which was found on Borneo last August, showed it breathed entirely through its skin, biologist David Bickford told AFP.
While many frogs breathe partially through their skin, the Barbourula kalimantanensis is the first to have entirely evolved away from having lungs, he said.
This runs counter to one of the key events in evolution, when animals developed primitive lungs and moved from water to land.
"Here is a frog that has reversed that trend, it has totally turned against the conventional wisdom, if you will, of millions of years of evolution," said Bickford, a biologist at the National University of Singapore.
The frog appears to have shed its lungs over millions of years to adapt to its home in the fast-flowing cold water rivers in the island's rainforests, Bickford said.
Cold water contains more oxygen, making it possible to breathe through skin, he added.
Only three other amphibians -- two species of salamander and a worm-like creature called a caecilian -- are known to have evolved to breath without lungs.
"It's like a cookie, it's almost completely flat. So initially when you pick it up in the water you know this thing is strange," said Bickford.
"It's surprisingly cute, you know, like a bulldog is cute. It's one of those things that is so ugly, it's cute."
While many animals have organs they no longer use -- such as the human appendix -- evolution normally works on the principle of "if it's not broke don't fix it," Bickford said.
"Most things we don't use don't get lost... so there had to be a big negative side-effect of having lungs for them to be lost."
Bickford believes lungs may have made the frog's ancestors too buoyant in the fast-flowing water, increasing their risk of being swept away.
The downside, Bickford said, is that the frog cannot survive on land or even in still water.
Indonesian scientist Djoko Iskandar, who accompanied Bickford on the expedition, first heard about the strange-looking creature 30 years ago and had been searching for it ever since.
He said that every time he went to Borneo he found habitats had been destroyed by industry, with pollution to rivers from gold mining apparently making it impossible for the frogs to breathe.
"We think that a little bit of pollution will affect the skin, and the skin is more important than for other species," said Iskandar, a scientist at the Bandung Institute of Technology in Indonesia, adding that even a small amount of pollution could be devastating.
Hundreds of new species of insect, animal and plant have been discovered on Borneo, with a find every month on average, conservation group WWF has said.
Other recent exotic discoveries include poisonous "sticky frogs," "forest walking catfish" able to travel short distances out of water and the transparent "glass catfish".
Related articles
Bizarre Frog discovered in Borneo Has No Lungs
Charles Q. Choi, LiveScience.com Yahoo News 7 Apr 08;
Read more!
Posts
visitors since Nov 07