An amphibious assault

LONDON

– The first images that come to mind may be unassuming brown newts or garden-variety green frogs, but amphibians cover a much grander spectrum.

Among about 6,000 species of frogs, salamanders and caecilians (legless animals, pronounced like “Sicilians”) are some of the world’s most bizarre animals: Giant Chinese salamanders, two metres in length; the “hairy frog” of Cameroon, which not only looks like it sports hair, but also can break its own bones to grow claws (an ability discovered just last month); the Surinam toad, which carries its eggs embedded in its back; and, even more macabre, the Sagalla caecilian, which feeds its own skin to its young.

Amphibians are also among the most colourful animals: The tiny, bright-yellow poison frog (with the spectacular scientific name Phyllobates terriblis) from Colombia, which is, gram for gram, the most poisonous vertebrate in the world; the black-dotted yellow frogs of Panama, which communicate with adorable hand waves; and the charismatic red-eyed tree frogs, aptly nicknamed “swimsuit calendar frogs.”

These make up just a small sample of the amazingly diverse amphibians, which have the longest history on earth. They predate all other terrestrial vertebrates.

But the first group of animals to colonize the land is also the first that humans are driving off it. Amphibians are disappearing faster than any other animals since the dinosaurs: 32 per cent of all species are threatened with extinction, compared with 23 per cent of mammals and 12 per cent of birds. Almost half are in decline.

The reasons are complex and vary among species. Some are hunted for the pet trade or, as with the Chinese salamander, for their meat. The destruction of habitat, as with all animals, is a major cause worldwide. Pollution also appears to be a big factor.

But one of the most worrisome and headline-grabbing causes is a strange fungus: Batrachochytrium dendrobatidis, a.k.a. chytrid. Nobody quite knows how it kills amphibians - it may smother them, covering the skin they use to absorb oxygen and water, or it might release toxins. But biologists are unanimous in their belief that it is wiping out amphibians across the tropics, in the warm and wet conditions in which they thrive, from Australia to South America. Scientists believe that it is behind the disappearance of 74 species (out of an original 110) of harlequin frog in Central America and at least 10 species of Australian frogs.

Bob Johnson, curator of reptiles and amphibians at the Toronto Zoo, saw one of the fungus’s first victims just before it vanished. The golden toad of Costa Rica was once so numerous that tourists would flock to witness their mating season. They were so dense on the forest floor, “we could barely walk, there were so many of them,” Mr. Johnson says of a trip he made in 1987. Just two years later, they had all disappeared, driven into extinction. “It was just astonishing.”

Now, Mr. Johnson is caring for one of the last populations of Panama golden frogs, the stars of the most recent David Attenborough BBC documentary, Life in Cold Blood. The frogs were all taken out of the wild before chytrid reached them too.

Humans may be responsible for the spread of the fungus: Scientists suspect that it came from its home in South Africa when clawed frogs were exported 50 years ago for use in pregnancy tests. (A dose of a pregnant woman’s urine causes a female clawed frog to lay eggs within eight to 12 hours. The test also works on male frogs, which produce sperm in response to the injection.)

African clawed frogs are mostly resilient to chytrid, and probably carried the fungus, but frogs elsewhere have little defence. It can wipe out a species in a matter of years.

Poster children

The reason for their vulnerability boils down to two things: They spend part of their lives in water and part on land, so they are exposed to factors in both environments; and their skin - not scaly like a reptile’s, but soft, thin and permeable - renders them more sensitive to things such as ultraviolet radiation, pesticides and disease.

As the most threatened group of animals on the planet, they are not just poster children for the biodiversity crisis, they are also harbingers of things to come. Because amphibians occupy a unique and crucial place in the food chain, their extinctions will ripple through the ecosystem and catalyze the rapid disappearance of other animals, large and small.

Their young - salamander larvae and frog tadpoles - are major bottom feeders. When they grow into adults and move onto land, they bring nutrients from the water with them.

“Usually water is a trap for biomass,” says McGill University zoologist David Green, one of Canada’s foremost authorities on amphibian declines. Things flow from land into water easily in rain, but amphibians, which move back onto land as adults, are one of the very few things in nature that move nutrients in the reverse direction, back onto land. “That’s a very important job,” Prof. Green says.

Moreover, as adults, they consume huge numbers of insects, then themselves are consumed in huge numbers by larger animals, such as birds and mammals. If we take these middlemen out of the food chain, the consequences could be disastrous. Insect populations could explode, while birds and mammals may disappear.

Yet, despite their importance, conservationists are struggling to raise the funds they need to save them.

“A charismatic bird or mammal will easily draw in money, but it is hard to get funding for amphibians,” says Helen Meredith, who is leading the Zoological Society of London’s EDGE amphibian-conservation program.

The London Zoo is caring for and breeding a number of spectacular amphibians, including the golden poison frog, and is sponsoring projects overseas for highly endangered amphibians such as the giant Chinese salamander (hunted for its meat in China, where it is considered a delicacy) and the spectacularly ugly purple frog of India, discovered just last year.

EDGE - meaning “evolutionarily distinct and globally endangered” - has found that 85 of the most distinctive and endangered 100 amphibian species are receiving little to no conservation attention. “Amphibians have been pushed into the shadows,” Ms. Meredith says.

“But in terms of conservation dollars, you can accomplish so much more than investing in any of the large ‘charismatic’ mammals,” says Kevin Zippel, director of Amphibian Ark, a branch of the World Conservation Union, which is supporting captive breeding programs.

Breeding amphibians is comparatively simple. They are small and fairly easy to take care of. “For just $50,000 to $100,000, you can save an entire amphibian species from extinction. Compare that to the amount it costs to rent one panda for a year from China: $1-million, and that doesn’t even include housing, food and staff.”

Amphibian Ark is trying to raise $50-million for the captive management of 500 species. “If each of the world’s largest zoos just took on one species each, we’d be done,” Mr. Zippel says.

“Though we aren’t saying that having these species in glass boxes is an acceptable form of conservation - it’s just an option for the future,” he adds.

Arks to tombs

But unless more effort is put into restoring their wild habitats, the “arks will only become tombs,” says ecologist Alan Pounds, who has been documenting the decline of golden toads and harlequin frogs in Central America since the 1980s. “We can’t save the world with captive breeding. We have always thought that if we have parks and reserves, then we can do what we want with the rest of the planet - and that is not true.”

He says the spread of chytrid in the mountains of Costa Rica is tied to global warming. His research, published in the journal Nature, indicates that the fungus causes more frog deaths in warmer years, when the hilltops - normally cool - become more hospitable to the fungus.

And it is happening not just in the mountains of Central America: Other researchers have tied the spread of the fungus in midwife toads in Spain to a warming climate.

But chytrid occurs in many places without being lethal. McGill’s Prof. Green has found it in about 13 per cent of amphibians from five Canadian provinces. “Canada would have to get warmer and wetter” for the fungus to become lethal, he says. “We may start to see that.”

Even if this doesn’t happen, frogs all over Canada are disappearing. Leopard frogs on the Prairies are vanishing, and nobody quite knows why. Fowler’s toads may be driven out of their only range, in Southern Ontario, where they are mowed over by beach grooming machines sent to remove cigarette butts. Chorus frogs in Quebec, along with their songs, are fading because of suburban development.

The precise causes can be hard to pin down, but many studies have implicated UV radiation, low doses of pesticides and agricultural pollution. Most ecologists believe that it is rarely one single factor that is responsible, but the combination of threats.

Ecologist Pieter Johnson at the University of Colorado published a landmark study in 2007 in the Proceedings of the National Academy of Sciences (PNAS) demonstrating that the combination of fertilizer runoff in ponds and the flatworm parasite Ribeiroia ondatrae may be responsible for the high prevalence of amphibian mutations that we see all over the United States and Canada (up to 70 per cent of frogs in some wetlands grow multiple arms and legs). High levels of fertilizers in ponds spawn blooms of algae, which in turn foster an explosion in snails which carry the parasites.

Many other studies have found such “synergistic effects.” Researchers from Oregon State University have shown that the combination of UV radiation and fertilizer pollution kills seven times more frogs than either alone.

Ecologist Rick Relyea at the University of Pittsburgh, who studies pesticides, reported in 2001 in the PNAS that subjecting tadpoles to the fear of a caged predator in their tank, combined with low levels of the pesticide carbaryl, caused grey tree frog tadpoles (found in Canada) to die when neither factor alone killed them. “Many people were shocked and amazed,” he says.

He has an upcoming paper in the journal Ecological Applications that will show that combinations of low doses of pesticides - non-lethal on their own - are “highly lethal.”

But Prof. Relyea cautions that we cannot be sure pesticides are causing frog declines in the wild - more research is needed. “The problem is that an awful lot of effort goes into assessing the benefits of these chemicals, but not the costs.” We just need to be smarter about how we use pesticides, he says, such as spraying them in minimal amounts and at times of year when amphibians are less vulnerable - for example, after the tadpoles have grown into frogs.

If pesticides are responsible for deaths in the wild, the impact could be more widespread than we realize. Ecologists from the University of Toronto reported last year that pesticides in the soils in Costa Rica were actually more concentrated higher up the mountains than lower down closer to plantations, carried aloft by breezes and deposited onto the mountaintops when mists form at high elevations.

Chemical cocktails

There is an important lesson to be learned here: Being so sensitive, amphibians are sending us a warning signal. For good reason, they are known as our canaries in the coal mine. “If we lose the amphibians, then we lose our best detection system to see what’s going on with the world,” EDGE’s Ms. Meredith says.

And not only that, we also lose “our tools for future drug production,” she says. Frogs harbour incredible cocktails of chemicals in their skin that are being investigated by medical researchers. The lethal poisons of arrow frogs may be harnessed for antibiotics, and seem to yield effective painkillers hundreds of times more powerful than morphine. The wood frog, widespread in Canada, can freeze solid and survive, and is being probed for clues to preserve frozen organs during transplant. Salamanders, which can regenerate their limbs, may some day help us to grow lost digits. And it was discovered just three years ago that certain red-eyed tree frogs produce a protein that can block HIV infection.

“On the back of some toad somewhere is the compound that will do wonders for you, but we don’t know which one it is yet,” Prof. Green says.

Already we have lost amphibian species to extinction that may have been able to help us. In the 1970s, scientists discovered a species of frog in Australia that gestated its eggs in its stomach, using special hormones to shut down its digestive system. It could have held the clues to treat ulcers, but it has not been seen in decades.

Before the 3,000 amphibians in decline suffer the same fate, is there anything we can do? When we are trying to fight the battle on so many fronts, is there any way to win the war?

We need to deal with every single issue at once: climate change, excessive use of agricultural fertilizers and pesticides, depletion of the ozone layer and, above all, habitat degradation.

But the case isn’t hopeless, Prof. Green says, as long as we take action now. “We have to give amphibians some credit,” he says. “They are not so vulnerable and fragile. It’s just the combination of factors that they cannot cope with. They are tough as boots if you give them a chance.”

Zoe Cormier is a science writer based in London.

HIGHLY ENDANGERED

Chinese giant salamander

The largest amphibian in the world. Has declined massively since the 1960s.

Primary threat is hunting. Considered a delicacy in China.

Chile’s Darwin frog

Carries young in mouth. May already be extinct.

Panama Golden Frog

No longer in the wild. Being bred at the Toronto and Vancouver zoos. Communicates with hand waves.

Olm

Blind. Lives in caves. May be able to live for more than 100 years and go without food for 10.

Purple frog

Just discovered in 2003. Critically endangered. Wonderfully ugly.

Golden poison frog

Most poisonous vertebrate on Earth.

***

WONDERFUL AND WEIRD

Hairy frog of Cameroon

Just spectacularly gross.

Pac man frog

Unlike any other amphibian, possesses teeth. Actually eats mice.

Australian red-eyed tree frog

One of many species of “red-eyed” tree frogs, or “swimsuit calendar frogs.” Produces protein in skin that can block HIV.

Surinam toad

Breeds young embedded in its back.

Betic midwife toad

Carries eggs around in a ball around its legs.

Zoe Cormier

From globeandmail.com

Bizarre frog can break its own bones to produce cat-like extendable claws

Biologists have described a bizarre, hairy frog, which in a gruesome process, actively breaks its own bones to produce cat-like extendable claws.

According to a report in New Scientist, the frog, known as Trichobatrachus robustus, has been described by David Blackburn and colleagues at Harvard Universitys Museum of Comparative Zoology.

The researchers believe that the gruesome behaviour of this frog is a defence mechanism, also observed in nine of the 11 frogs belonging to the Astylosternus genus, most of which live in Cameroon.

T. robustus actively breaks its own bones to produce claws that puncture their way out of the frogs toe pads, probably when it is threatened. This indicates that this gruesome behaviour might serve as a defence mechanism for the frog.

The claws of T. robustus, found on the hind feet only, are nestled inside a mass of connective tissue. A chunk of collagen forms a bond between the claws sharp point and a small piece of bone at the tip of the frogs toe.

The other end of the claw is connected to a muscle.

Blackburn and his colleagues believe that when the animal is attacked, it contracts this muscle, which pulls the claw downwards. The sharp point then breaks away from the bony tip and cuts through the toe pad, emerging on the underside.

The end result may look like a cats claw, but the breaking and cutting mechanism is very different and unique among vertebrates. Also unique is the fact that the claw is just bone and does not have an outer coating of like other claws do.

Because Blackburn has only studied dead specimens, he said that hes unaware what happens when the claw retracts or even how it retracts.

It does not appear to have a muscle to pull it back inside, so the team thinks it may passively slide back into the toe pad when its muscle relaxes.

Being amphibiansit would not be surprising if some parts of the wound heal and the tissue is regenerated, said Blackburn.

Some frogs grow spines on their thumbs during breeding season, but this is entirely different, said Ian Stephen, curator of herpetology at the Zoological Society of London, UK. For me, it highlights the need for a lot more research on amphibians especially in light of the threat of mass extinctionshe added.

From Thaindian news.

Snake Mystique

Since the beginning of recorded time, snakes have been labeled with bad reputations. Some of these ridiculous misconceptions stem from superstitions, others from religious dogmas, but the majority of these opinions are formed out of fear and ignorance of the unknown.

The only way to gain a deeper insight into the truth is to study the facts. Snakes play a very important role in our delicate ecological system, and we owe it to ourselves as dedicated sportsmen to learn more about them.

 

This coiled rattler is shaking its tail as a defense mechanism. Be forewarned that snakes can strike almost half their body length. A 4-foot snake can reach you from 2 feet away. Rattlers account for the majority of bites in the Western States.

The annual statistics in the United States for reported snake bites fluctuates between 7,000-10,000 people. The majority of victims are men, and most bites occur below the knee. Approximately 10-15 deaths are attributed to these venomous snake encounters.

Because of warmer climates, snakes in Southern states pose the greatest risk for deer hunters. Alabama, Arizona, Florida, Georgia and Texas are among the leaders in snake reported incidents.

Large snakes are the only God-given predators with the keen ability to slither down rat-holes and other hard to reach places, and effectively control vermin such as rats and mice. It takes a snake approximately seven years of growth to reach a suitable size to be able to swallow some of the larger rodents such as these. Unfortunately, many are killed before reaching maturity by people who are oblivious to their environmental value.

 

This is a coral snake. They are easily identified by the three rings of color located on their body. The easy way to remember the color scheme is to memorize the old saying: Red touch yellow, kill a fellow. The harmless milk snake is often confused with this serpent

Snakes are cold-blooded reptiles and when the weather turns cool they seek shelter. When it freezes they go into hibernation. Most snake bites occur between the months of April and October when temperatures are relatively warm. Snakes like to lie up and hide in woodpiles, blow-downs, tall grass, rock crevices and underneath things that provide shelter.

All pit vipers can be identified by their vertical pupils, and the heat sensing pits located between their eyes and nostrils. These unique serpents are capable of detecting variances in heat from as far away as 30 feet.

When you’re walking through the forest, watch where you step, and be mindful of where you sit. If in doubt, use a solid stick to probe where you’re exploring, and pay attention at all times. Always carry a flashlight, and use it at night, because snakes like to hunt after dark.

The ability to recognize venomous snakes from harmless ones isn’t as complicated as many would think. I’ve included some detailed photos with this article, and by studying them, the average person shouldn’t have any trouble distinguishing the difference. All it takes is a little effort. I avoided using the term “poisonous snake” because this is a misnomer. There’s a distinct difference between venom and poison.

In the regions of North America where you and I pursue whitetails, there are basically four types of indigenous species to contend with: The rattlesnake family, copperheads, cottonmouths (nicknamed water moccasins) and coral snakes.

The first three serpents are classified as pit vipers and are easily identified by their vertical pupils, and the heat sensing pits located between their eyes and nostrils. These reptiles have the unique ability to sense variances in heat from as far away as 30 feet.

 

The copperhead is probably responsible for more snake bites in the southeastern U.S. than any other species. Observe the natural camouflage, how it blends in nicely with this rock. These snakes can be very hard to see when they’re mixed in with brown leaves and darker foliage.

The rattler’s territory spans the largest, and various species can be found in almost every state in the union except Alaska, Hawaii and Maine. Some of the southern provinces of Canada are also home to these snakes.

Coral snakes have round pupils. They inhabit the costal regions of the southern United States, and favor semi-tropical climates. These reptiles can be identified by the three rings of color located on their body: red, yellow, and black. The old saying, red touch yellow, kill a fellow, is an easy way to remember the color sequence. Sometimes the harmless milk snake is confused with this deadly reptile because of a similar color scheme.

There are two types of venoms and both of these pose different threats. Pit vipers have retractable fangs similar to hinges and their bites are hemotoxic, affecting the circulatory systems of their victims. Their venom has digestive enzymes, which immediately begin breaking down tissue and blood, in and around the effected areas. Because of these necrotic effects, the wounded areas often turn black after a few days.

 

This harmless black snake is one of the most effective rodent predators on earth. Observe the round pupils. It’s a shame to see one these beneficial serpents mistaken for a venomous snake and killed by a misguided person who doesn’t recognize its environmental value.

The coral snake’s venom is neurotoxic, and can affect breathing and other central nervous system functions. These serpents have small mouths with fixed fangs, making it harder for one of these reptiles to inflict its bite. They have to chew on their prey to envenom them.

Something I’d like to bring to everyone’s attention that might stir some controversy among experts like herpetologists, is information pertaining to the Mojave rattler. Recent snake bite cases in the western United States have indicated that some of these snakes are developing both hemotoxins and neurotoxins, making their bites extremely dangerous. This anomaly has baffled some of the researchers, and I thought it necessary to mention this in this article.

First aid recommendations have drastically changed over the course of time, because of good medical research. Some of the old survival manuals and hunting guides, which recommended cutting yourself and applying tourniquets, are now obsolete. These methods have been proven to cause more tissue damage and can make matters worse.

 

All pit vipers have retractable hinged fangs, which can grow up to 2 inches in length. Be aware, that approximately 20 percent of bites are dry, meaning that the snake failed to inject its venom.

Statistically, you stand a greater chance of being struck by lightning while on a hunting trip, than you do of being bitten by a venomous snake.

If you’re one of the unfortunate ones who happen to be envenomed, the authorities on the subject advise staying calm and seeking medical attention immediately. If you have a snakebite kit, the venom extractor should be applied within the first few minutes to be beneficial. Be aware that dry bites do occur in approximately 20 percent of snake strikes. A dry bite is categorized as failure to inject venom. When this happens, it’s still wise to go to the hospital and let someone qualified examine your wound.

Another word of advice, when you reach your hunting vehicle or deer camp, avoid placing ice directly on your bite. Doing this can cause more localized damage, because it impedes the venom from dissipating. A small loose constricting band placed above the bite is the final thing recommended while en-route to the hospital. Make sure that you can easily slip your fingers through whatever you use, and do not tighten it.

I know five men who have been bitten by pit vipers and all of them are still alive to tell their tales. One of these gentlemen is in his 80s, and after recovering, he’s back to work in his garden. I’ve never met anyone who’s been struck by lightning.

 

This is a young cottonmouth (water moccasin). These snakes are notorious for showing you the whites of their mouths when they assume a defensive posture

Currently, there are two antivenins available in the United States. Crotalidae is the older serum, and this treatment produced allergic reactions in approximately 20 percent of patients it was administered to. The newer and more advanced antivenin, CroFabz, uses venom from every species of venomous snakes found in the U.S., and has proven to be very effective. Less than one percent have allergic reactions. The only problem with CroFab is availability, because it’s relatively new, some hospitals might not have any on hand.

Be forewarned that a pit viper with a decapitated head can inflict a deadly bite. A tough snake’s nervous system can still function for up to 30 minutes, and some of them are still capable of perceiving and responding to stimuli. If you’re ever forced to terminate a snake’s life, then be careful, treat it with respect, and don’t make any foolish mistakes.

Maintaining a healthy snake population is just as important as maintaining and regulating a proportional deer herd. Nature does have a balance, and as good stewards we need to ensure that our children, and the generations to come can enjoy the things that we’ve all been blessed with.
  
In closing, I’d like to thank herpetologist Kelly Irwin, and wildlife rehabilitation specialist and ornithologist Tommy Young for their helpful assistance and guidance. Without their advice, some of the important details included in this article wouldn’t have been possible.

By Steven E. Stillwell

From Buckmasters

Unique Adaptive Evolution Found In Snake Proteins Provide New Insight Into Vertebrate Physiology

Prior to the advent of large sequence datasets, it was assumed that innovation and divergence at the morphological and physiological level would be easily explained at the molecular level. Molecular explanations for physiological adaptations have, however, been rare. Pollock and colleagues now provide evidence that major macroevolutionary changes in snakes (e.g., physiological and metabolic adaptations and venom evolution) have been accompanied by massive functional redesign of core metabolic proteins.

“The molecular evolutionary results are remarkable, and set a new precedence for extreme protein evolutionary adaptive redesign. This represents the most dramatic burst of protein evolution in an otherwise highly conserved protein that I know of,” said Dr. David Pollock, a professor of Biochemistry & Molecular Genetics at the University of Colorado Denver School of Medicine.

Over the last ten years, scientists have shown that snakes have remarkable abilities to regulate heart and digestive system development. They endure among the most extreme shifts in aerobic metabolism known in vertebrates. This has made snakes an excellent model for studying organ development, as well as physiological and metabolic regulation. The reasons that snakes are so unique had not previously been identified at the molecular level. In this recent study by Pollock and colleagues, the researchers show that mitochondrially-encoded oxidative phosphorylation proteins in snakes have endured a remarkable process of evolutionary redesign that may explain why snakes have such unique metabolism and physiology.

Amino acids that are normally highly conserved in these proteins have been altered, affecting key molecular functions such as proton transfer (which establishes a proton concentration gradient that drives energy production in the cell). In addition to the accelerated burst of amino acid replacements, evidence for adaptation comes from the remarkable levels of molecular coevolution and convergence that were observed.

The function of core oxidative metabolic proteins in vertebrates remains extremely controversial, mostly because of the difficulty of experimentally manipulating these membrane-embedded proteins. By integrating analyses of molecular evolution with protein structural data, the authors show that critical functions of mitochondrial proteins, such as the channeling of oxygen, electrons, and protons through cytochrome C oxidase, have been fundamentally altered during the evolution of snakes. Snakes have been previously proposed as an ideal metabolic, physiological, and ecological model system to study evolution, and the current results support that idea, showing that their utility as a model system can extend to the molecular level.

“Snakes are an invaluable resource for structural biologists and biochemists, who can use comparative genomics to generate hypotheses on how COI and oxidative phosphorylation function, and how these functions may be altered and redesigned,” said Dr. Todd Castoe, a lead author on the paper.

“We believe that our results will provide a textbook case as the most clear and dramatic example of adaptive evolution in a core metabolic protein to date, as well as providing the implication that strong molecular and physiological adaptation can be linked,” said Pollock.

“The manuscript represents an important milestone in molecular evolution and vertebrate adaptation, and opens up clear and well-justified directions for further research. Snake metabolic proteins may significantly clarify understanding about the operation of these critical yet functionally elusive metabolic proteins.”

Funding was provided through an NIH training grant and other NIH grants. These funding sources had no role whatsoever in preparation of the manuscript.

From ScienceDaily

Transitional Frog Lays Eggs on Water and Land

When our distant ancestors were making their way out from the water, they had to evolve a way to lay their eggs on land.

Now a tree frog could help shed light on this mysterious, pivotal moment in history. This little yellow Panamanian amphibian is the first known vertebrate that can lay its eggs both in water and on land.

The researchers looked at the hourglass treefrog (Dendropsophus ebraccatus), which is also known as the pantless treefrog because part of its leg lacks color. This amphibian typically lays its eggs on plants hanging over ponds. After tadpoles hatch, they simply fall into the water. Now Boston University scientists Justin Touchon and Karen Warkentin find these frogs can lay egg masses directly in or on ponds.

(”Treefrog” refers to the family Hylidae, of which this species is a member. “Tree frog” in general refers to any frog that lives in trees.)

Stinky  work

To see how these amphibians choose between laying their eggs in water or on land - and to understand the demands our distant ancestors might have faced to make this shift - the researchers investigated three ponds in Panama.

“It can be messy, dirty, stinky work,” said Touchon, a behavioral ecologist. “I wouldn’t say it’s necessarily hard work. But you do have to wade out waist deep into these hot tropical ponds, and the mud smells awful and decaying, and deal with mosquitoes and many other biting insects.”

Two of the ponds were covered by shade from trees, and the frogs laid their eggs on the vegetation above the water. In a third pond in an old gravel quarry without a forest canopy, the vast majority of the eggs - about three-quarters - were laid in water, supported by aquatic vegetation. The other roughly one-quarter of the eggs were laid on leaves above the pond, although the mortality rate of these eggs was high due to the heat and lack of shade.

“We were in the right place at the right time to make this discovery,” Touchon recalled. “We were wading into the middle of the quarry pond at night looking for frogs - there are at least 10 different species of frog there out and calling on any given night - and we happened upon a pair that was laying its eggs in the water.”

Environment rules

To see if genetic differences made frogs lay eggs in water or on land, the researchers built miniature ponds in an open field and in the forest. Their findings showed that environment and not genetics was key here. Frogs placed in the shaded ponds laid their eggs above the water, and ones in unshaded ponds deposited eggs in the water.

Although humans did not evolve from frogs, our evolution does go back to other, albeit long extinct amphibians. Our remote ancestors might have evolved reproduction on land to escape aquatic predators or to cope with alterations in the environment just as these treefrogs do, improving their chances of surviving changes in habitat or climate.

“Hopefully understanding what drove the evolution of reproduction on land will give clues to what led the movement out of the water in general by all animals,” Touchon told LiveScience.

It turns out the eggs of these frogs are not ideally suited for either land or water. Eggs in the water have the challenge of getting enough oxygen, while eggs on land risk drying out, among other things. “They’re not as good at surviving on land or in the water as eggs specialized for either, but they can do both,” Touchon noted.

The most surprising thing about this discovery of an animal that can lay eggs both aquatically and terrestrially “is that nobody has actually seen something like this before,” Touchon said. “Terrestrial egg-laying has evolved many times in frogs, so there might be multiple transitional species capable of both aquatic and terrestrial breeding. It was probably because no one had thought to look for such transitional species before - until now, it was always thought frogs were either aquatic or terrestrial breeding.”

Evolution key

Knowing about these frogs gives researchers “the first opportunity to test the different ideas regarding the evolution of terrestrial breeding,” Touchon explained. “We could conduct experiments manipulating the aquatic environments or the terrestrial environments and see how that affects the survival of eggs in either environment - change the predators, for instance, or the humidity.”

And while this frog is the first vertebrate known that can lay its eggs both in water and on land, the researchers emphasize that it is probably not alone. The researchers plan to investigate closely related frogs. It may turn out this might not be limited to amphibians - quite a few fish are known to lay their eggs outside of the water, and it’s very possible that some of those species can lay both in and out of water as well, Touchon said.

Discovering other animals capable of both aquatic and terrestrial breeding is important “because terrestrial breeding has evolved so many times, it will be interesting to see if the same factors were involved, or perhaps different ones, to hopefully turn up more pieces of the puzzle,” Touchon said.

Touchon and Warkentin detailed their findings online May 19 in the journal Proceedings of the National Academy of Sciences. Their research was funded by the National Science Foundation, Boston University, the Smithsonian Institution and The Animal Behavior Society, and supported by the Smithsonian Tropical Research Institute.

From redOrbit

Another new species of lizard discovered in India

Another new species of ground dwelling lizard, Hemidactylus sataraensis, has been discovered in India by a team from the Bombay Natural History Society (BNHS). The geckos belonging to this genus are chiefly arboreal and many of them are well known to humans. The lizards or geckos which are common in houses mostly belong to this genus. In India there are 21 species in this genus, however this new lizard from Maharashtra is the largest species of Hemidactylus from India.   

This distinctive new species of gecko is chiefly rock dwelling and occurs on the cliffs in the northern Western Ghats. This gecko was first photographed by herpetologist Mr. Ashok Captain of Pune. After consultation with Mr. Varad B. Giri, of the Bombay Natural History Society, and Dr. Aaron M. Bauer of Villanova University they realised that this is an interesting and as yet undescribed species. Dr. Aaron M. Bauer is an expert on lizards and an authority in this group.

Unique herpetofauna diversity

The discovery of a new, large, rock dwelling species of Hemidactylus proves the fact that this region has a unique diversity of herpetofauna. Presently this species is only known from the type locality, but by looking at habitat preference of this species, it is strongly felt that it may be present in other regions of the northern Western Ghats and needs immediate attention. This also highlights the need for more intensive systematic surveys in this region to document the diversity. And the data generated will eventually be utilized to conserve the species and its habitats.     

Varad had submitted his findings to a scientific journal, Hamadryad which are published recently. Varad had named this new species honouring Dr. Bauer as Hemidactylus aaronbaueri.  

For further details contact:

Varad B. Giri
Scientist ‘B’
Bombay Natural History Society
Mumbai
Mobile: 9223542581
Tel.: 22821811 (office)
E-mail: varadgiri@gmail.com

Courtesy of Varad B. Giri, of the Herpetology Section of Bombay Natural History Society of Mumbai.

From Wildlife Extra

Still just a lizard

I found a blogpost that I can´t help myself from sharing with you..

“The title gets the principal objection of any creationist out of the way: yes, this population of Podarcis sicula is still made up of lizards, but they’re a different kind of lizard now. Evolution works.

Here’s the story: in 1971, scientists started an experiment. They took 5 male lizards and 5 female lizards of the species Podarcis sicula from a tiny Adriatic island called Pod Kopiste, 0.09km², and they placed them on an even tinier island, Pod Mrcaru, 0.03km², which was also inhabited by another lizard species, Podarcis melisellensis. Then a war broke out, the Croatian War of Independence, which went on and on and meant the little islands were completely neglected for 36 years, and nature took its course. When scientists finally returned to the island and looked around, they discovered that something very interesting had happened.

The original population of P. sicula was still present on Pod Kopiste, so we have a nice control population. These lizards are small, fast, insect-eaters in which the males defend territories.

Sadly, P. melisellensis on Pod Mrcaru had been extirpated. So we had a few innocent casualties of the experiment.

The transplanted P. sicula thrived and swarmed over the island of Pod Mrcaru, but they were different, and they had evolved in multiple ways.

The original P. sicula were insectivores who occasionally munched on a leaf; approximately 4-7% of their diet was vegetation. The P. sicula of Pod Mrcaru, though, had adopted a more vegetarian diet: examining their gut contents revealed that 34% of their diet was plants in the spring, climbing to 61% in the summer…and much of this diet was hard-to-digest stuff, high in cellulose. This is a fairly radical shift.

There were concomitant changes. The lizards’ skulls were wider, deeper, and longer, and they had stronger bites — a necessity for chomping off bits of tough plants, instead of soft mosquitos. Instead of chasing bugs, they’re browsing stationary plants, and their legs are shorter and they are slower. Population densities are higher. The Pod Mrcaru lizards no longer seem to defend territories, so there have been behavioral changes.

Still just a lizard, I know.

Now here’s something really cool, though: these lizards have evolved cecal valves. What those are are muscular ridges in the gut that allow the animal to close off sections of the tube to slow the progress of food through them, and to act as fermentation chambers where plant material can be broken down by commensal organisms like bacteria and nematodes — and the guts of Pod Mrcaru P. sicula are swarming with nematodes not found in the guts of their Pod Kopiste cousins.

Here’s a photo (how could I resist an opportunity to show some lizard guts?). The top ones may be a little difficult to interpret; what they’ve done is slit open the tube of the gut, and then use some pins to hold the tube open so you can see the little ridge or flap that rings the interior.

The cecal valves are an evolutionary novelty, a brand new feature not present in the ancestral population and newly evolved in these lizards. That’s important. This is more than a simple quantitative change, but is actually an observed qualitative change in a population, the appearance of a new morphological structure.

Evolution created something new, and it did it quickly (about 30 generations), and the appearance was documented. It’s still just a lizard, but we expected nothing else — and it’s now a lizard with novel adaptations for herbivory.”

From Pharyngula`s blog.

Amphibian Ark Announces ”Walking Frog” Naming Auction

Highest Bidder Wins Exclusive Naming Rights to Frog Species from Ecuador

ST. LOUIS–(BUSINESS WIRE)–Amphibian Ark, a global conservation organization formed in an effort to help save the world’s amphibians from mass extinction, is announcing its first frog naming rights auction, beginning immediately. The highest bid made on www.CharityBuzz.com will win the naming rights to a newly discovered species in the genus Osornophryne, an endangered “walking frog” indigenous to the remote Andes Mountains in Ecuador.

From one-third to one-half of the planet’s 6,000 amphibian species – frogs and toads, salamanders and newts, and caecilians – are in danger of extinction and the walking frog is no exception. The causes for these declines and extinctions come in different forms, including habitat loss, climate change, emerging diseases, pollution, and over-collection for food and pets.

“After thriving for 360 million years, frogs are in harm’s way,” said Jean-Michel Cousteau, supporter of Amphibian Ark and founder of the Oceans Future Society. “Because amphibians are the first to feel the effects of environmental stressors that could ultimately harm humans, the time to act is now.”

Walking frogs are known for having no tadpoles; instead hatched eggs release froglets. And, instead of jumping, they walk slowly along the forests of the Andes.

The winning bidder’s selected name will be published in a scientific journal. Arrangements can also be made to tour the conservation facilities in Ecuador that will protect the species, and see other endangered amphibians in their natural habitat.

The proceeds will be used by Amphibian Ark partners in Ecuador to save some of the country’s most endangered amphibian species – including the new, walking frog. The auction is being conducted by CharityBuzz.

Auctioning off naming rights for species is a growing tactic by wildlife protection organizations to raise the funds necessary to protect our planet’s biodiversity. Recent auctions have allowed philanthropists to name butterflies, monkeys, and fish.

“We are very proud to be working with Amphibian Ark in their incredibly worthy project to help raise money to protect endangered amphibians,” said Coppy Holzman, CEO of CharityBuzz.com. “Based on our prior species naming experience, we fully expect this series of frog naming auctions to be very successful and encourage everyone to visit the site and aid this worthy cause.”

In order to make a bid or learn more about Amphibian Ark and the new walking frog species, please visit http://www.charitybuzz.com/area.do?id=773.

Amphibian Ark is a partnership between the World Association of Zoos and Aquariums (WAZA), IUCN/SSC Conservation Breeding Specialist Group, and IUCN/SSC Amphibian Specialist Group. It was formed to develop, promote, and guide short term captive management of threatened amphibians, making possible the long-term survival of species for which adequate protection in the wild is not currently possible. For additional information about Amphibian Ark please visit www.amphibianark.org.

Chameleons are dying out

Chameleons or Girgits — a term often used to define politicians — are fast becoming an endangered species in the country. Zeylanicus (Chameleon) is the only lizard family that originally belongs to Pakistan and India. Several years ago, the entire green belt of Thar in Sindh was their natural habitat but now these rare species can only be found in Nagar Parkar, owing to the greenery there.

Recently Dr Theodore, a Professor at the California University, visited the Sindh government-run, Rann of Kutch Wildlife Sanctuary (Nagar Parkar) for the second time and collected some specimens for research purposes. The foreign expert’s visit was arranged jointly by the Zoological Survey Department (ZSD) of Pakistan and the Sindh Wildlife Department (SWD) officials.

Dr Theodore is conducting a research in order to find any similarities between the rare lizard specie population residing in the Indian and Pakistani wildlife sanctuaries. He is expected to come again in July this year for acquiring further information about the specie.

With 70-80 million years of evolution and some of the most grotesque physical characteristics, the chameleon is doubtlessly one of the most intriguing lizards. Like most of its relatives, it dwells exclusively in trees and thickets.

These species are able to change their skin colour, which is an expression of the physical and physiological condition of the lizard. Different chameleon species are able to change colours which include pink, blue, red, orange, green, black, brown and yellow, which is why they are able to blend into their surroundings. However, recent research has indicated that chameleons may also change their colour as a method of communication, including making themselves more attractive to potential mates.

Syed Shamim Fakhri, a field observer of the Zoological Survey Department, said that the chameleon changes colours to protect itself. It prefers to live at the top of a tree. He rejects the notion that it is poisonous and added that it is a friendly animal but can not survive in a different environment. It eats particular insects in the wild. Fakhri also claimed that the chameleon is only present in the Sindh province.

Not only government-run zoos, but also private individuals also keep chameleons as pets. Local people are hunting down or capturing these endangered species which has become a lucrative business, therefore violating many international laws.

More than 160 kinds of chameleon species are at present, arranged in nine genera and are mostly oviparous, and some are ovoviviparous. The oviparous species lay eggs after a 3-6 week gestation period. The female digs a hole in the ground, anywhere from 4-12 inches (10-30cm) deep depending on the species. The female turns herself around at the bottom of the hole and deposits her eggs. Once finished, the female buries the eggs and leaves the nesting site. Clutch sizes vary greatly with species.

Though Pakistan is a signatory of international laws about the export of endangered species and their hunting, still various species have been under threat due to a lack of implementation of certain laws.

Despite the fact that the ZSD and SWD have experts but due to the lack of funds in the relevant departments, they are unable to conduct adequate research.

From The News

Amphibian Ark: 5 for Frogs..

AMPHIBIAN ARK JUMP STARTS RESCUE WITH 5 FOR FROGS 

 

Five month campaign to raise $500,000 and save five species of frogs

 

 

 

MINNEAPOLIS, Minnesota, USA ( May 1, 2008 )

 

 

 

 

 

Amphibian Ark, a global conservation organization created to raise awareness and rally fundraising to protect endangered amphibian species, announced today the commencement of its 5 for Frogs campaign. 5 for Frogs is a grassroots crusade with the goal of raising $500,000 to save five endangered species in five months.

The ”pay it forward” spirit behind 5 for Frogs asks kids and adults to do something to help frogs, salamanders, and other amphibians through acts of kindness involving the number 5. It could be as simple as someone telling or emailing five people about the looming mass extinction of amphibians. Or, it could be holding a charity car wash or selling cookies to raise $5, $50, or even $500 for Amphibian Ark to allocate to rescue projects. If thousands get involved, each can play a part in saving five or more species from extinction. Fifty ideas for getting involved in 5 for Frogs are listed on the Amphibian Ark Web site at www.amphibianark.org.

The May kickoff of 5 for Frogs starts with a U.S. national FrogWatch on May 3 involving hundreds of students who will monitor the environmental health status of amphibians in their communities through a cooperative effort organized by the National Association of Biology Teachers (NABT) and the National Wildlife Federation. FrogWatch is a volunteer-based program that encourages everyone to help by getting outdoors and monitoring local wetlands for breeding frogs and toads.

“Not since the disappearance of the dinosaurs have we seen an extinction of this magnitude,” said Jean-Michele Cousteau, supporter of Amphibian Ark and founder of the Oceans Future Society.

“Because amphibians are the first to feel the effects of environmental stressors that could ultimately harm humans, and they play a critical role in our ecosystem, the time to act is now.”

In addition to the grassroots activities, 5 for Frogs will feature several global, special events throughout the summer. Five species of amphibians that have not yet been given common names will have their naming rights auctioned, with proceeds earmarked for Amphibian Ark. And, an endangered Mexican species, the Large-crested toad, will receive special visibility on Cinco de Mayo, celebrated, of course, on the fifth day of the fifth month.

 

5 for Frogs

Add One

 

“The Year 2008 has been dubbed The Year of the Frogs by conservationists from around the world to highlight the amphibian crisis and to save the most endangered species from extinction. As a result, the 5 for Frogs campaign could not come at a better time in an attempt to channel these efforts.”

Amphibian Ark is a partnership between the World Association of Zoos and Aquariums (WAZA), IUCN/SSC Conservation Breeding Specialist Group, and IUCN/SSC Amphibian Specialist Group. It was formed to develop, promote, and guide short term captive management of threatened amphibians, making possible the long-term survival of species for which adequate protection in the wild is not currently possible. To learn more about Amphibian Ark, the 5 for Frogs campaign, and to review 50 inspirational and creative ways to raise funds for amphibians, please visit www.amphibianark.org

 

A couple of good links related to this project.

5 for frogs fact sheet.

50 ways to save amphibians.