Hibernation physiology, freezing adaptation and extreme freeze tolerance in a northern population of the wood frog

Rana sylvatica is a species of wood frog whose special abilities boggle the mind. A study recently published in The Journal of Experimental Biology explains how they manage to be frozen, but not to death.

National Geographic reports, "The tiny amphibians can survive for weeks with an incredible two-thirds of their body water completely frozen—to the point where they are essentially solid frogsicles.

Even more incredible is the fact that the wood frogs stop breathing and their hearts stop beating entirely for days to weeks at a time. In fact, during its period of frozen winter hibernation, the frogs’ physical processes—from metabolic activity to waste production—grind to a near halt. What’s more, the frogs are likely to endure multiple freeze/thaw episodes over the course of a winter."

The frogs have cryoprotectants, or solutes in their blood that dramatically lower their freezing temperature. It protects the body's cells and limits the amount of ice that can form in the body.

By having a higher concentration of these cryoprotectants in its blood, this species of wood frog can survive being frozen even multiple times in a single winter. (Source)

It's been gone since 1983, but the Lazarus Project has brought it back to life.

In 1983, the world lost one of its weirdest frogs. The gastric-brooding frog, native to tiny portions of Queensland, Australia, gave birth through its mouth, the only frog to do so (in fact, very few other animals in the entire animal kingdom do this--it's mostly this frog and a few fish). It succumbed to extinction due to mostly non-human-related causes--parasites, loss of habitat, invasive weeds, a particular kind of fungus. There were two subspecies, the northern and souther gastric-brooding frog, and they both became extinct in the mid-80s sometime.

Except--what if they didn't?

Taking place at the University of Newcastle, the quest to revive the gastric-brooding frog became known as the Lazarus Project. Using somatic-cell nuclear transfer (SCNT), a method for cloning, the project has achieved the major step forward of creating an early embryo of the extinct frog. Essentially, they found a related frog--the great barred frog, which also lives in Queensland and has cool eye markings, like it's wearing sunglasses--deactivated its eggs, and replaced them with eggs taken from the extinct frog.

Even though the gastric-brooding frog has been extinct for decades, it's possible to do this because individual specimens were kept preserved in, believe it or not, everyday deep freezers. When going through somatic-cell nuclear transfer, the eggs began to divide and form into the early embryo stage.


The embryos didn't survive much longer than that, but it was confirmed that these embryos contain genetic information from the gastric-brooding frog--that yes, in fact, they have brought it back to life. The researchers are confident that this is a "technical, not biological" problem at this stage to breed gastric-brooding frogs to adulthood. This is a big step forward for the worldwide attempts to revive extinct animals--the Lazarus Project researchers will soon meet with those working to revive the woolly mammoth, dodo, and other extinct beasties to share what they've learned.


Oh, and in case you were wondering: the gastric-brooding frog lays eggs, which are coated in a substance called prostaglandin. This substance causes the frog to stop producing gastric acid in its stomach, thus making the frog's stomach a very nice place for eggs to be. So the frog swallows the eggs, incubates them in her gut, and when they hatch, the baby frogs crawl out her mouth. How delightfully weird!
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This tiny frog’s “mighty war cry” is intended to ward off predators and attract mates, reports GrindTV, but it’s probably just going to make you say “awww.”

Although it’s been widely identified in the news as a Namaqua rain frog, frog expert (unfortunate professional title: herpetologist) Alan Channing has identified it as a desert rain frog.

I’m pretty sure Mr. Channing knows what he’s talking about, as he’s actually one of the assessors list on the International Union for the Conservation of Nature and Natural Resources (IUCN), which lists the desert rain frog, or Breviceps macrops, as “vulnerable” on its Red List of Threatened Species.

The Pokemon-like sound is also emitted when the frog is in distress, said Mr. Channing, who is a professor and has authored three books on African frogs.

“What this means is that somebody was prodding it and annoying it while the close-up video was taken,” he said.


Dang it, now I’m saying “awww” because I’m sad for the squeaky little guy.

Wildlife photographer Dean Boshoff, who filmed the squeaky frog, said it was already making that sound, and that’s how he noticed it.


“I recorded a short clip of the defensive cry of the Desert rain frog – Breviceps macrops,” Mr. Boshoff wrote in the video’s caption on YouTube. “While walking along the sand dunes in Port Nolloth, a coastal town in the Northern Cape province, it alerted me to its presence with its fearsome war cry. I knelt down and proceeded to photograph and film this unusual creature’s behaviour.”
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The species – known as Helen’s Tree Frog (Rhacophorus helenae) - is bright green with a white belly and has webbed hands and feet like parachutes to glide from tree to tree.

Dr Rowley was stunned to discover the large, 10cm long species surprisingly close to Ho Chi Minh City, an urban centre with over 9 million people.

Dr Rowley said it was incredibly rare and very exciting to find a new species of frog less than 100km from one of the largest cities in South East Asia.

“To discover a previously unknown species of frog, I typically have to climb rugged mountains, scale waterfalls and push my way through dense and prickly rainforest vegetation,” she said.

“I certainly didn’t expect to find a new species of frog sitting on a fallen tree in lowland forest criss-crossed by a network of paths made by people and water buffalo, and completely surrounded by a sea of rice-paddies.”

Dr Rowley said the large frog has likely evaded biologists until now by spending most of its time out of sight, in the canopy of large trees.


Dr Rowley said she chose to name the frog species in honour of her mother, Helen Rowley, who has steadfastly supported her only child trekking through the forests of Southeast Asia in search of frogs.

“My mother was recently diagnosed with ovarian cancer and I thought it was about time that I showed her how much I appreciate everything she’s done for me and everything that she’s put up with over the years,” she said.

To date, Helen’s Tree Frog is only known from two patches of lowland forest in the middle of agricultural land not far from Ho Chi Minh City.


Dr Rowley said lowland forests are among the most threatened habitats in the world.

“Another, more well-known species reliant on lowland forests, the Javan Rhino, was confirmed extinct in Vietnam in October 2011,” she said.

“The new species is at great risk due to ongoing habitat loss and degradation - the greatest threat to amphibians throughout Southeast Asia – but hopefully it has been discovered just in time to help protect it.”
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A rare blue frog was sighted Tuesday by forest preserve volunteers at the Hidden Lake Forest Preserve near Downers Grove.

The bullfrog, spotted by volunteer Jerry Zamirowski of Glen Ellyn, had a rare mutation causing the frog to appear bright blue, according to the DuPage County Forest Preserve District.

It is the first sighting of a bullfrog with that mutation on record in the county.

“When [Zamirowski] sent in the photo we said ‘This is really fascinating,” said DuPage County Forest Preserve District public affairs specialist Bonnie Olszewski. “There are all kinds of reasons why animals might have mutations like genetics or conditions that might cause color mutation, but this bright blue I don’t think we’ve ever seen anything exactly like that before.”

The frog’s vibrant coloration is likely due to an inability to camouflage properly with the green, marshy area, according to Dan Thompson, ecologist at the DuPage County Forest Preserve.

“We’ve learned from school that you mix blue and yellow and you get green, but this individual is without those yellow pigment cells and so it is physically unable to make that green coloration,” he said. “This is one of those just very rare situations.”

The bullfrog appears to be an adult, a surprise to Thompson who declared the frog’s age “pretty incredible since it can’t camouflage itself quite properly.”

Thompson said the mutated frog is a “genetic anomaly,” but it may naturally occur more often than recorded and the animals go unnoticed.(Source)

Four decades after Kermit the Frog first sang "It's not easy being green," amphibians around the planet know all too well how he felt. It's not just difficult being green anymore — these are hard times to be a frog of any color.

Frogs and toads today face a gauntlet of environmental threats, part of what the International Union for Conservation of Nature calls an "amphibian extinction crisis." Nearly one-third of Earth's 6,485 amphibian species are on the brink of extinction, according to Save the Frogs, a California-based conservation group.

One of the biggest factors in this has been the deadly chytrid fungus, which is blamed for major declines or extinctions of more than 200 amphibian species worldwide. But the plight of frogs (and toads, which are technically frogs) is also compounded by many other dangers. Deforestation, wetland loss and climate change are wiping out their habitats; pollution and pesticides are permeating their skin; invasive species are stealing their food; and overharvesting for food and pets is draining their gene pools.

The fourth annual Save the Frogs Day is this Saturday, April 27, organized by Save the Frogs and observed by frog fans from Oregon to Ghana to Bangladesh. In honor of the holiday, here are a dozen photos of frogs and toads from around the world, highlighting the beauty and diversity of Kermit's embattled brethren:

LOOK BEFORE YOU LEAP: An American bullfrog, the largest frog species native to North America, surveys its surroundings in Mountainville, N.Y. (Photo: Nick Harris/Flickr)













SOURCE

This frog thinks it's people.

The video of this bullfrog sitting on a bench like a human has become one of the most shared and viewed videos on YouTube in recent days, perhaps because ... well, because, just look at this thing.

"Never seen nothing like this before," writes user RoltonB in the video's description. "The video was shot entirely fortuitously. The frog is OK. There is no nails, no glue, animal abuse, etc. Later, she jumped off the bench and galloped away to the water."

Glad to hear the frog wasn't hurt. It just wanted to see what all the fuss about sitting on a bench was about.

Bullfrog

The American bullfrog (Rana catesbeiana or by some authorities as Lithobates catesbeianus) often simply known as the bullfrog in Canada and the United States, is an aquatic frog, a member of the family Ranidae, or “true frogs”, native to much of North America. This is a frog of larger, permanent water bodies, swamps, ponds, and lakes, where it is usually found along the water's edge.On rainy nights, bullfrogs, along with many other amphibians, travel overland, and may be seen in numbers on country roads.

American bullfrogs live longer in warm weather. They have been widely introduced across North America (see range map). The original, naturally determined range did not include the far western regions where it is found today. (Wikipedia)

The discovery of a new frog species in New Guinea is pretty big, but the frogs aren't.

The newly found frog species, Paedophryne amauensis, is the world's tiniest known vertebrate, according to a press release from Louisiana State University. Averaging less than one-third of an inch (7.7 millimeters) in length, the frogs are able to fit in the center of a U.S. dime.

Published Wednesday in the journal PLoS ONE, the discovery was made by a team of American researchers led by Louisiana State University herpetologist Chris Austin.

Austin said in the press release, "It was particularly difficult to locate Paedophryne amauensis due to its diminutive size and the males' high pitched insect-like mating call. But it's a great find. New Guinea is a hotspot of biodiversity, and everything new we discover there adds another layer to our overall understanding of how biodiversity is generated and maintained."

Paedophryne amauensis steals its tiny crown from Paedocypris progenetica, an Indonesian fish that averages over eight millimeters in length.

It also beats out two other Paedophryne species which were discovered in New Guinea in December as the world's smallest tetrapod, or vertebrate with four limbs. Paedophryne dekot and Paedophryne verrucosa both average under 10 millimeters in length, according to National Geographic, but they are larger than Austin's new frog.

The discovery was a challenge for Austin and his team, but a frog's life may be a little more difficult. A report from 2011 found that the demand for frog legs is driving some frog species to extinction. The global frog trade is also reportedly causing the "spread of a fungus called chytrid, which kills frogs in droves along with other amphibious populations."

208 new species -- including several frogs -- were discovered in Southeast Asia in the past year, but they are threatened by "habitat loss, deforestation, climate change and overdevelopment," according to the World Wildlife Fund.

Source

You might not believe it until you hear the frog sing for your self, but a newly discovered frog species in Vietnam actually vocalizes like a bird song.

The Australian Museum in Sydney posted the audio file and is hosting it because one of their researchers, Jodi Rowley, discovered the frog in the mountain forests of Vietnam. Clearly, hearing a bird song or something like one in a forest would not lead one to believe a frog was close by, but Rowley made the discovery anyway. It was found in the Pu Hoat Proposed Nature Reserve and named Quang’s tree frog (Gracixalus quangi). Forest habitat between about 1800 and 4200 feet is where it lives. Fortunately this frog discovery does not also include the information that it is already known to be in danger of extinction, as some new species discovery stories do.

What makes the frogs song more bird-like is that it constantly changes, whereas frogs typically have a very simple and repetitious vocalization. Rowley explained, “In fact, no two calls that I recorded were exactly the same, with each frog mixing clicks, whistles and chirps in no apparent order! It is the most variable frog call that I’ve heard of, and sounds a lot more like a bird song than a frog call.” (Source: Mongabay.com)

She has previously discovered new frog species in Vietnam including one with ‘fanged’ tadpoles, with black curved hooks in their mouths. In the video below she talks about that discovery (not the singing frog). This video was included to show her talking about her research.


The male Quang's tree frog has uniquely complex vocalizations. Photo by: Jodi J. L. Rowley/Australian Museum.





Globally, the world's amphibians are facing an extinction crisis. It's believed that at least 120 amphibians have gone extinct in the last 30 years, while 41 percent of the world's 7,000 known amphibians are considered threatened with extinction by the IUCN Red List. Deforestation, wetland loss, pollution, overexploitation, the pet trade, invasive species, and climate change have all taken a toll on these sensitive creatures, which have been dubbed by many ecologists as "canaries in a coal mine" for their ability to point out environmental degradation. In addition, a deadly fungal disease called chytridiomycosis has wiped out whole species even in pristine environments.

Scientists recently made a fascinating discovery of the tiniest frogs in the world. These two species of frogs were found in Papua, New Guinea and both are smaller than a penny. Their size runs about 0.4 inches (8-9 millimeters) in length. Not only are they the smallest frogs ever found, but they are also the smallest of a group of animals called tetrapods (four-legged animals with backbones). Their scientific names are Paedophryne dekot and Paedophryne verrucosa. The name P. dekot comes from the word for "very small" in the local language Daga and P. verrucosa was named from the Latin word for "full of warts," due to its distinctively lumpy skin. At this time it is not known who their closet frog relatives are.

These two species, along with 2 other slightly larger varieties live in the small mountain ranges of southeastern Papua, New Guinea and its offshore islands. Because of their small size they can have only two eggs, which limits their ability to reproduce. Other species of frogs usually have lots of eggs per litter, so this small number is considered to be very rare. They also seem to have hit the lower limit of body size for frogs and toads, so it's unlikely that researchers will find anything much smaller.

They have found a niche on the forest floor, where their tiny body size allows them to hide among leaf litter and moss. This is because due to their tiny size, their fingers and toes are too small to allow for much climbing. It is also thought that they might eat tiny arthropods, such as mites. Since they also lose moisture very quickly, this restricts them to live in very wet tropical forests. Much more will soon be revealed about their way of life as scientists continue to study them. It is a very exciting discovery in the world of amphibians.

Scientists have recently discovered that the amphibian populations are most likely to accelerate in decline, some to the point of extinction, more than was previously thought. They have analyzed the geographical spread of the main threats to frogs, toads and other amphibians and found that the richest regions in terms of biodiversity are also the ones that are under the greatest threat. Climate change and the loss of habitats due to changes in the way land is used are acting as a double whammy instead of effecting them independently.

Amphibians are thought to be particularly vulnerable to human activities because they depend on both terrestrial and aquatic habitats for survival. They also have a porous skin that easily absorbs environmental pollutants. In addition they are being attacked by the chytrid fungus, which is suspected to be spread by the commercial trade in frogs and toads.

Researchers have mapped out the level of threats to amphibians on a global scale based on climate change, land-use and fungal disease. This effort was led by Professor Carsten Rahbek of Copenhagen University. What they found was that the highest concentrations of amphibians are experiencing the greatest changes to their landscapes.

It was also found that the regions where climate and land-use change tended to overlap that they had the highest projected impact on the amphibians. In contrast, the threat posed by the fungal disease showed little spatial overlap with the other two threats.
As was noted by Professor Tim Halliday of Open University, "In my view, amphibians are indicators of a much larger problem, the global deterioration of freshwater habitats. The WWF Living Planet Report has shown that biodiversity is declining faster in freshwater than in any other biome, including coral reefs and tropical forest."

Conservationists predict that about a third of the estimated 6,000 amphibian species in existence are in peril. This new study backs up that prediction that climate change and habitat loss will combine to boost the rate at which species become extinct. Another sad comment on how we as a human species are steadfastly destroying our planet and the life that depends on it.

There once was a young woman who was very vain. Her father was the village chief and her family was very respected. Many young men wanted to marry her, but she thought that she was too good for all of them. One day, she and her sister were walking beside the big lake in their village. That lake had many frogs. Several of them were sitting on a mud bank, in the middle of the lake, and she started making fun of them.

"How ugly those frogs are," she said. Then, she stooped over and picked up one which was sitting on the shore and looking at her.

"You are so ugly," she told that frog. "Even another frog wouldn't marry you!!" With that, she threw the frog back into the lake.

That very night, when the young woman stepped outside of her lodge to walk, while everyone else was sleeping, she was surprised to see a young man standing there. His clothing was decorated with beautiful green beads and he was very handsome.

"I have come to marry you," the young man told her. "Come with me to my father's house."

The young woman agreed. She had never seen such a handsome young man and wanted to be his wife.

"We must climb this hill to get to my father's house," the young man said and he pointed to the lake. They started to walk down to the water, but to the young woman, it felt as though they were climbing a hill. When they got to the water, they didn't stop...they went under.

The next morning, the young woman's family noticed that she was missing. They looked everywhere for her and when they discovered the footprints leading to the water, they decided that she must have drowned.

They beat the drums and held a death feast. People, in the village, cut their hair and blacked their faces and mourned the loss of the young woman.

One day, however, a man was walking down by the lake. When he looked at the middle, he saw a lot of frogs sitting on the mud bank. And there, in the middle of all those frogs sat the chief's lost daughter!!! He began to wade out towards the frogs, but they leaped into the water, and took the young woman with them.

The man went very quickly to the chief's home. "I have seen your daughter!" he said. "She has been taken by the frogs. I tried to get to her, but the Frog People took her with them under the water."

The young woman's mother and father went down to the lake. There, they saw their daughter sitting on the mud bank surrounded by the Frog People. Just like before, when the chief tried to reach her, the frogs leaped in and carried her under the lake with them.

Then, the chief's other daughter spoke.

"My sister insulted the Frog People," she said. That is why they have taken her.

The chief knew then what he must do. He made offerings to the Frog People, asking them to forgive his daughter. They placed dishes of food on the surface of the water. The dishes floated out, to the middle of the lake, and then sank. But, the frogs wouldn't give the young woman up.

Then, the chief placed robes, of fine skins, on the bank. The young woman and the Frog People came to the bank and took the robes. But, when the chief came close, the Frog People drew her back into the lake.

The Frog People just would not give up. At last, the chief had a plan. he gathered together all of the people in the village.

"We will dig a trench," he said. "We'll drain all of the water out of the lake, and rescue my daughter."

The people dug for a long time and the water began to drain away.

The Frog People tried to fill the trench with mud, but they couldn't stop the water from flowing out of the lake. The Frog People tried to drive the people away, but the people only picked up the frogs and dropped them back into the water. They were very careful not to hurt any of the frogs, but they didn't stop digging the trench. The water kept flowing out and the homes of the Frog People were being destroyed.

At last, the chief of the Frog People made a decision. After all, it was his son who married the young woman.

"We aren't strong enough to fight these humans," he said. "We must give my new daughter-in-law back to her people."

So, they brought the young woman to the trench. Her father and mother saw her and pulled her out. She was covered with mud and smelled like a frog!

One frog leaped out of the water after her. It was the frog that had been her husband. But, the people carefully picked him up and put him back into the lake.

The chief took the young woman home. For a long time, she could only speak like a frog does.

"Huh, Huh, Huh!!"

But, finally, she began to speak like a human again.

"The Frog People know our language," she told the people. "We must not talk badly about them."

So from that day on, the people showed great respect to the Frog People. They learned the songs that the woman had brought from the Frog People and they used the frog as an emblem.

They learned a great lesson. They never forgot what happened to the young woman who was too proud. To this day, when the people of the village hear the frogs singing, they say that the Frog People are telling their children this story too.

The Tlingit* are the northenmost of the Northwest Coast peoples (which also includes, among others, Haida, Tsimshian, Kwakiutl, Nootka, Salishan, Chemakum, Chinook, and Makah) who lived traditionally by fishing and hunting marine animals and built large plank houses, totem poles, and ocean-going dugout canoes. Source

More frog legs Madame? Monsieur? A very popular appetizer in France and also in Belgium. Who would have ever dreamed that this "delicacy" would have global implications? But the global demand for these little creatures is pushing them into extinction.

Each year billions of frogs are either captured from the wild or are being farmed to be sold as food to restaurants or markets. Most of these frog farms can be found in Asia, in countries such as Indonesia Bangladesh, Malaysia, and India. The main problem with this international frog trade is that it is also affecting frogs in the wild who play an important role in the environment and in controlling human diseases such as malaria, and encephalitis. They do this by eating disease spreading insects such as mosquitos.

Wild frogs are being killed off by the spread of the chytrid fungus. This fungus has already killed one hundred million frogs and has already driven some wild species into extinction. Recently a study in the U.S. estimated that 62 percent of the bullfrogs entering California from Asian frog farms were infected with the chytrid fungus. Bullfrogs are perfect carriers for this deadly fungus.

Also because of the huge demand in western Europe, frogs in Indonesia and other Asian countries may be driven into extinction because of those countries trying to satisfy the demand. Europe does not allow harvesting of frogs for consumption there because of the huge decline of native frog species, but they are not above importing from the Asian countries. Therefore the decline of many frog species are being endangered globally by just a handful of countries in Europe.

So what just seemed like just another tasty appetizer on your plate is actually causing global implications for the health of our planet and the human population also. Those who are consumers of frog legs must take all of this into consideration as this situation cannot be allowed to continue without dire consequences.

"Frogs are survivors, making peace with two worlds. And yet they are so sensitive. Whatever happens to the environment in which a frog population lives will be soon apparent in the frogs themselves. They are a litmus for pollution, poor little frogs. They are so beautiful and come in so many sizes and colours. When they leap, they just leap! Nothing graceful, just a big flop, arms and legs akimbo, flying haphazardly through the air. And sometimes they get a lot of bugs. And sometimes they don't."