When researchers found fire salamanders (Salamandra salamandra) in the Netherlands dying at a rapid rate from a skin fungus, they thought the infection looked familiar.

Globally, amphibian numbers are declining in large part due to a chytrid fungus known as Batrachochytrium dendrobatidis or Bd. Bd attacks the skin of its host causing “the outer layers of the epidermis to thicken,” says the Academy’s amphibian expert, Dave Blackburn. “Bd disrupts the function of amphibian’s skin by interfering with electrolyte transport.”

Bd is quick and deadly: its effects may have wiped out more than 200 species of amphibians worldwide.

Similarly, the fire salamanders are dying at a rapid rate. Since first seeing dead animals in the Netherlands in 2010, scientists have observed that the population has fallen to around 10 individuals, less than four per cent of the original numbers.

But the similarities end there. The infected fire salamanders display skin lesions or ulcers and when the animals were tested, they were negative for Bd.

So what gives? According to a paper published last week in the Proceedings of the National Academy of Sciences, a new chytrid fungus.

Batrachochytrium salamandrivorans or Bs is closely related to Bd, but an entirely new chytrid fungus species.

This study is incredibly important, Blackburn says. “It clearly shows three things: 1) Bs is a new species of chytrid, 2) it presents different pathology than Bd (these lesions), and 3) it may have different host specificity.”

Bs, like Bd, doesn’t kill every amphibian it meets. “Midwife toads, Alytes obstetricans, are among the most susceptible of European frogs to Bd,” Blackburn says. But the study researchers infected the toads with new fungus Bs, and they were not susceptible to that fungus.

But the evidence the study provides only brings more questions for Blackburn. “When we think some amphibians around the world were killed by Bd, could it have been something else? Bs? Yet another species of chytrid?”

He gives an example of the thermal range for Bs and Bd. “People trying to predict how Bd spreads and where it would thrive—the fungus may be absent from that location now, but where it might flourish given the right conditions—by modeling where the disease is now with information on climatic conditions. In the past, have we been looking at the thermal range for Bd only or might we have confused some records of Bd with what we now know as Bs? Each may have different thermal conditions and there could be errors to where we’ve predicted that the disease could thrive.”

Testing for the new chytrid fungus also presents a conundrum. Although tests have been developed to screen for Bd, it is not clear whether these might sometimes be detecting Bs instead. The authors of the new study have developed primers to test for Bs, and Blackburn and his lab will obtain these to test animals here at the Academy.

Blackburn and other scientists came back with live frogs from Cameroon earlier this summer. The team hopes to raise and breed the animals here, displaying them for the public. As we reported in a story a few weeks ago, the frogs are part of a new initiative at the Academy focused on amphibian conservation and biodiversity education.

The Cameroonian frogs were screened and tested positive for Bd. They are being treated with a proven microbial solution, but now Blackburn is worried about Bs. “How widespread is Bs?”

And Blackburn has more and more questions… “Does it only affect salamanders? We’ve seen salamander declines in Central America—it looks like Bd, but could it be Bs? We found skin lesions on amphibians in Cameroon with mortality events, Bd was not present when tested. Could we have found Bs, instead?

“How is it spread, is it totally different from Bd? Why are we seeing these now? How is climate change affecting the emergence, spread, and change of prevalence? How do you stop them?

“Bs really opens the door for further research,” Blackburn says.

Image: Didier Descouens/Wikipedia

“…They are essentially solid frogsicles.” That’s Stefan Sirucek in National Geographic describing the latest publication on frozen frogs. Sounds like the Triplets of Belleville (click for image), n’est-ce pas?

Jon Costanzo and his Miami University (Ohio, that is, not Florida) colleagues studied the antifreeze mechanics of Alaskan wood frogs (Rana sylvatica) that allow the amphibians to survive temperatures down to minus 16 degrees Celsius. The team collected several dozen specimens and reproduced the frogs’ frozen winter conditions in their lab in Ohio.

“We kind of faked them out as if they were being subjected to decreasing temperature and decreasing daylight like they would experience in the field,” Costanzo explains.

Costanzo, somewhat of an animal winter-stress expert, had a “completely unexpected” finding with the Alaskan frogs. They broke down muscle protein, which is surprising because they would have to breed soon after emerging from hibernation.

The team believes that the frogs are using nitrogen in the protein to produce urea. Although humans and other creatures also produce urea, a waste byproduct, they quickly release it from their bodies. The frogs don’t.

“Rather than urinating to get rid of the urea, they’re hanging onto it and they really stacked it up,” Costanzo says. “The concentration of urea in their blood was just huge and way more than we’d ever seen in the frogs from Ohio. We’ve never seen the accumulation like we’ve seen in these Alaskan frogs. It’s really spectacular.”

Urea, a cryoprotectant, can help tissues survive freezing stresses and also stabilize membranes. It also helps depress metabolism while the frogs hibernate for nearly eight months.

The research also found the frogs produce glucose, which is ordinary blood sugar, as they’re freezing and accumulate that to high levels, too, which appears to help the cells tolerate freezing.

Another key: dehydration.

“We don’t know exactly how they are dehydrating their organs during freezing but we know the organs shrink,” Costanzo said. “The idea is that rather than have all that water remain in the organ and freeze and become big chunks of ice, have that water freeze outside where it’s not going to harm the tissue structure.”

See? Frogsicles! And it’s not just a frozen treat. Costanzo and his colleagues hope that understanding the Alaskan frogs’ antifreeze system might have implications for human organ transplants. Très bien!

The research was published last week in the Journal of Experimental Biology.

Image: Brian Gratwicke/Wikipedia

Two very different Academy scientists traveled to Cameroon together earlier this summer, in search of frogs, in a race to save them.

We’ve cited this scary number on this website before: more than one third of amphibians are at risk of extinction. These species experience many threats, mostly due to human impact, but one clear causes of frog death is the chytrid fungus. Scientists are unsure how it spreads, but the disease it causes quickly kills its victims.

Dave Blackburn, a scientist here at the Academy’s Institute on Biodiversity Science and Sustainability (IBSS), is working with San Francisco State University’s chytrid expert (and Academy fellow), Vance Vredenburg, to learn more about the spread and treatment of chytrid.

Brian Freiermuth works with the Academy’s live animals, mostly herps (amphibians and reptiles), and joined Blackburn on this unusual expedition. The two Academy scientists were joined by other students and colleagues, all looking for and collecting different samples.

“This expedition was exciting because we were conducting a lot of different types of science,” Blackburn, the expedition leader, explains. “We had four grad students with us. Two from UC Berkeley—one of them studies African frogs, the other looks at the larger ecosystem and how many frogs might live at a particular pond. One woman from the University of Texas is studying alkaloids on frogs’ skin and we also had a Cameroonian scientist who studies caecilians on the team. ”

While each team member had a very important role, Freiermuth performed a very crucial and unusual job for this type of expedition—keeping frogs alive during their journey through the country and all the way back home to San Francisco.

One of his biggest challenges was temperature since air conditioning isn’t always available or reliable in the country. “Keeping frogs alive for weeks at a time in less than ideal conditions in multiple locations isn’t easy,” says Freiermuth.  “Transporting the frogs from remote areas is hard to do because you don’t have any way to keep them cool in the vehicles, which get very warm during while traveling. I packed a large number of gel packs in our Styrofoam transport box and packed the frogs in individual vials. I also set the frogs up in cages in the field, and fed them until we would move to another location.”

Blackburn and Freiermuth also worked out cozy travel back to the US for the frogs. The amphibians were allowed in the cabin on Air France.

The frogs are now in quarantine here at the Academy, and will make their home in the Steinhart Aquarium by the end of this year, on display for visitors to see. The frogs were chosen because the Steinhart biologists believe they will do well in captivity but also because these are species of conservation concern for which we know little of their biology.

And they are here for a more important mission, too. The Cameroonian frogs are part of a new initiative at the Academy focused on amphibian conservation and biodiversity education. “This new initiative will enable us to figure out aspects of the biology of these many animals that we know so little about,” Blackburn says. The idea is that the more we know, the more we can protect and sustain populations.

“One basic goal of our work at the Academy is to better understand the conditions necessary for reproduction: breeding preferences (where are the eggs laid?), tadpole biology (what type of water quality do they require?), and requirements to get through metamorphosis (how long do they take to get to metamorphose, how long do they live, how long until they first reproduce, etc.),” Blackburn continues. “We can learn more about all of the species we collected in Cameroon: Cardioglossa pulchra, Cardioglossa gracilis, Hyperolius riggenbachi, Hyperolius ademetzi and Xenopus longipes.”

Science Today will follow up with two videos this fall: one on our new initiative and one on the fight against the deadly chytrid fungus. In the meantime, you can see some of Freiermuth’s amazing photos from the Cameroon expedition here.

Image: Brian Freiermuth

Batrachochytrium dendrobatidis (Bd) is the deadly chytrid fungus killing amphibians worldwide. Researchers have tracked the fungus to African clawed frogs (Xenopus laevis) in South Africa back to 1934, but how did it leave Africa—and those frogs—to cause the recent decline and extinction of 200 frog species worldwide?

Vance Vredenburg of San Francisco State University wants to know. In 2008, he witnessed a population of frogs he studied in Sequoia and Kings Canyon National Park drop 99.9% due to Bd.

Working with a team of researchers at Stanford, Vredenburg began looking at the herpetology collection here at the Academy. Our own Jens Vindum offered the team several specimens of African clawed frogs to swab for DNA samples. The scientists focused on specimens collected from wild populations in California between 2001 and 2010.

African clawed frogs were imported to the US between the 1930s and 1950s for use in pregnancy tests. The frogs ovulate when injected with a pregnant woman’s urine.

“Today, these frog populations are often found in or near urban areas, probably because hospitals released them into the wild when new pregnancy testing methods were invented in the 1960s,” Vredenburg says. Since then, the frogs have established feral populations throughout North America, including Golden Gate Park.

Sure enough, the Academy’s California specimens of African clawed frogs carried Bd. “This is the first evidence of the disease among introduced feral populations in the US, and it suggests these frogs may be responsible for introducing a devastating, non-native disease to amphibians in the United States,” says Vredenburg.

And although the species is a known Bd carrier, these amphibians don’t succumb to the fungus. “It’s amazing that more than half a century after being brought to California, these frogs are still here, and they still carry this highly infectious disease,” remarks Vredenburg. “This implies that there must be a stable relationship between the pathogen and the frogs, whereas there are other frog species, for example in the Sierra Nevada, which have been wiped out by the pathogen.”

The team also tested archived Academy specimens collected in Africa between 1871 and 2010 and found evidence confirming that Bd was present among indigenous populations of this species before they were exported worldwide.

Although no longer used in pregnancy testing, African clawed frogs are still imported to the US for use in biomedical and basic science research. Because of their suspected role as a carrier of the Bd fungus and other potential pathogens, eleven states have already restricted the importation of these frogs, by requiring special permits and not allowing them to be sold as pets.

The study was published last week in PLoS One.

Stay tuned—this summer, Science Today will document Vredenburg’s and Academy researcher Dave Blackburn’s fight against Bd.

Image: Michael Linnenbach/Wikipedia

Now, an international team of researchers has sequenced the genome of one of the two living species of coelacanths. The results are published in this week’s Nature.

The endangered African coelacanth (Latimeria chalumnae) has more up its sleeve than just the living fossil thing. Scientists have long thought that this group of fishes gave rise to the first four-legged amphibious creatures to climb out of the water and up on land. Lobe-finned fishes (with fins like limbs) are genealogically placed in-between the ray-finned fishes, such as goldfish and guppies, and the tetrapods—the first four-limbed vertebrates and their descendants, including living and extinct amphibians, reptiles, birds, and mammals.

Results from the genomic study place the coelacanths behind lungfish, another lobe-finned living fossil, as the closest fishy relative to tetrapods. But other data from the study still make coelacanths incredibly interesting.

These prehistoric-looking fish are evolving at a very leisurely pace. “We found that the genes overall are evolving significantly slower than in every other fish and land vertebrate that we looked at,” says co-author Jessica Alföldi, of the Broad Institute of MIT and Harvard.

“We often talk about how species have changed over time,” says Kerstin Lindblad-Toh, another co-author from the Broad Institute. “But there are still a few places on Earth where organisms don’t have to change, and this is one of them. Coelacanths are likely very specialized to such a specific, non-changing, extreme environment—it is ideally suited to the deep sea just the way it is.”

Researchers also found several key genetic regions that may have been “evolutionarily recruited” to form tetrapod innovations such as limbs, fingers, and toes, and the mammalian placenta. One of these regions, known as HoxD, harbors a particular sequence that is shared across coelacanths and tetrapods. Tetrapods likely co-opted this sequence from the coelacanth to help form hands and feet.

“This is just the beginning of many analyses on what the coelacanth can teach us about the emergence of land vertebrates, including humans, and, combined with modern empirical approaches, can lend insights into the mechanisms that have contributed to major evolutionary innovations,” says the paper’s lead author, Chris Amemiya of the Benaroya Research Institute.

Image: Ballista/Wikipedia

The team of researchers, working for the International Union for Conservation of Nature (IUCN), released a report called Priceless or Worthless? In addition to being online and in print, the report was presented at the IUCN World Conservation Congress in South Korea on Tuesday.

The report (a must read!) lays out the statistics of these rapidly declining plants and animals and explains why it’s important to save them, regardless of how much they help the human race.

“The donor community and conservation movement are leaning increasingly towards a ‘what can nature do for us’ approach, where species and wild habitats are valued and prioritized according to the services they provide for people,” says Jonathan Baillie, Director of Conservation at the Zoological Society of London. “This has made it increasingly difficult for conservationists to protect the most threatened species on the planet… While the utilitarian value of nature is important, conservation goes beyond this. Do these species have a right to survive or do we have a right to drive them to extinction?”

As Baillie implies, humans are at the root of most of these threats. The report describes funding, policy, legal and even marketing standpoints of why we need to and how we can save these species.

And while you can see galleries of these threatened species on National Geographic, New Scientist and Wired, really, go read and look at the report online. The images are phenomenal and the urgency of the risks of extinction leap from the page. (Did we mention it’s a must read?)

From plants and fungi to amphibians and mammals, all life is valuable. A quote from Georgina Mace in the report perhaps explains it best:

Every living species represents one unique pathway to success, developed over millions of years. What we lose with each passing species can never be replaced.

Image: Dr. Richard Bartlett/Wikipedia

This week, UC Berkeley announced the amazing growth of its project, AmphibiaWeb, an online catalogue of the world’s amphibians created to encourage more field monitoring and lab studies of the threatened animals.

David Wake, an Academy fellow from UC Berkeley, started the project in 2000 because amphibians were declining at a terrifying rate and he was concerned we’d lose species we didn’t even know existed. “In 1985, there were a handful of amphibian biologists in the whole world,” he says. “Now, the numbers [of scientists] have increased dramatically, and we are getting to the ends of the earth.”

The Academy’s amphibian biologist Dave Blackburn has contributed to AmphibiaWeb for about ten years and recently became more involved in expanding the project. “I joined the steering committee nearly three years ago. I actively work as part of a team on issues related to the systematics displayed on AmphibiaWeb, but, perhaps more importantly, am actively invested in ways of improving our services, such as an iPhone app (available for download now, but major improvement coming soon!), summary diagrams of evolutionary relationships among amphibian groups, and general ideas for improving the content for diverse viewers.”

The more viewers the better. Earlier this summer, the International Union for the Conservation of Nature and Natural Resources (IUCN) assessed that about 41 percent of amphibian species are at risk of extinction, and some are already extinct. These charismatic creatures are disappearing for many reasons—a warming Earth, increasing population, widespread use of pesticides and a deadly fungus.

But AmphibiaWeb is succeeding! With only about 4000 species known in 1985, AmphibiaWeb now boasts 7,000 species! Woo-hoo! (Fist-pump or –bump!)

Now that’s something to sing about! “An undergraduate researcher assisting with AmphibiaWeb suggested the idea of a song when it came to celebrating the scientific description of the 7,000th amphibian,” Dave explains. “We’ve known since early this year that we’d probably hit number 7,000 some time in the summer based on the rate of descriptions of new species over the past few years. I happen to have a good friend (Conor Loughridge, performing as The Wiggly Tendrils) from college that writes songs for a living. We asked if he would be willing to help us out, and when he said yes, Conor and I worked together on content for the song (though the rest was left up to him to make it catchy and fun!).

“The general idea is to simply catch attention,” Dave adds. “The idea is to highlight the excellent work done by amphibian biologists around the world and the fact that we are still in a crisis. We are losing many populations and species of amphibians around the world due to climate change, habitat degradation and destruction, disease and pollution. In some cases, we’ve lost them before we even knew they existed.”

What a great way to spread the news! Is the tune stuck in your head yet? Pass it along!

Image: Alessandro Catenazzi

In a surprising reversal of fortune, Israeli researchers have found a certain group of beetle larvae that feed on frogs.

As Ed Yong reports in his Discover blog:

During its lifetime, a frog will snap up thousands of insects with its sticky, extendable tongue. But if it tries to eat an Epomis beetle, it’s more likely to become a meal than to get one.

The larvae have shown 100% success in their ability to lure the frogs into becoming a meal. In fact, these beetles eat nothing else in the larval stage. Here are the gruesome details.

According to the researchers, Epomis larvae combine a sit-and-wait strategy with unique movements of their antennae and mouthparts to draw the attention of an amphibian (frogs and toads were used in the study). Thinking it has spotted potential prey, the amphibian comes closer and the larva increases the intensity of these enticing motions.

When the amphibian attacks, the larva manages to avoid the predator’s tongue and uses its unique double-hooked mouthparts to attach itself to the amphibian’s body and initiate feeding, which can include both sucking of bodily fluids and chewing body tissues, usually killing the much larger amphibian.

“It seems that instead of serving as food items for amphibians, Epomis larvae have evolved to specifically take advantage of amphibians as a food source,” says researcher Gil Wizen.

These findings extend the perspective of co-evolution in the arms race between predator and prey and suggest that counterattack defense behavior has evolved into predator-prey role reversal.

The research is published in the online journal PLoS ONE. Images and video of the beetle and the frightening attack can be found at Wired and Discover.

Image: Gil Wizen/AFTAU

Newts have the amazing ability to regenerate limbs and more, according to Ed Yong in his Discover blog:

They can regenerate parts of their tails, jaws, ears, hearts, spines, eyes and brains.

Very cool, right? But wait there’s more. A new study, published this week in Nature Communciations finds that the newts can do this at any age and over and over and over again, regenerating the exact same body part.

Researchers from Ohio and Japan removed the eye lenses from six Japanese newts (Cynops pyrrhogaster) a total of 18 times each over a 16-year period. And each time an identical eye lens grew back. In addition, reports New Scientist:

By the end of the study the newts were 30 years old, five years older than their average lifespan in the wild. Even so, the regenerated lenses from the last two excisions were indistinguishable from lenses of 14-year-old adults that had never regenerated a lens.

Could this finding have an impact on human health? Ed Yong is doubtful:

Scientists have studied amphibian regeneration for 200 years, with no discernible impact on medicine yet.

While lizards lack the skills for regeneration, they possess excellent problem–solving abilities, according to a Duke University study published this week.

The researchers used an intelligence test usually reserved for birds. They tested anoles from Puerto Rico (Anolis evermanni) using a wooden block with two wells: one empty and the other holding a worm covered by a cap. Four lizards, two male and two female, passed the test by either biting the cap or bumping it out of the way.

The lizards solved the problem in three fewer attempts than birds need to flip the correct cap and pass the test—birds usually get up to six chances a day, but lizards only get one chance per day because they eat less. In other words, if a lizard makes a mistake, it has to remember how to correct it for a full 24 hours. The results were published online in Biology Letters.

This is not the first study demonstrating lizards’ braininess, writes Science News:

[Georgia State’s Walter] Wilczynski’s lab has demonstrated that whiptail lizards can learn and unlearn tasks, and researchers led by Gordon Burghardt of the University of Tennessee at Knoxville have described monitor lizards learning how to get food out of a lab device…

Lizards indeed deserve more respect, says Wilczynski…

Indeed they do.

Image: Manuel Leal/Duke University