Tag: Reptiles

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Snakes have adapted their vision to hunt their prey day or night

For example, snakes that need good eyesight to hunt during the day have eye lenses that act as sunglasses, filtering out ultraviolet light and sharpening their vision while nocturnal snakes have lenses that allow ultraviolet light through, helping them to see in the dark.

New insights into the relationship between ultraviolet (UV) filters and hunting methods in snakes is one of the findings of the first major study of visual pigment genes and lenses in snakes — published in the advanced online edition of Molecular Biology and Evolution.

The new research was an international collaboration between snake biologists and vision experts led by the David Gower and included fellow Natural History Museum researchers Bruno Simões and Filipa Sampaio. Much of the research, including most of the DNA analyses, was carried out in the Museum’s laboratories.

Scientists have long known that snakes have highly variable sets of rods and cones — the specialised cells in the retina that an animal uses to detect light. But until now, most modern studies of vision in vertebrates (animals with a backbone) have concentrated on mammals, birds and fish.

To see in different colors, animals use visual pigments in their rods and cones that are sensitive to different wavelengths of light. The researchers examined the genes involved in producing the pigments from a broad genomic survey of 69 different species of snakes. What they found was as the genes vary from species to species so does the exact molecular structure of the pigments and the wavelengths of light they absorb.

The new research discovered that most snakes possess three visual pigments and are likely dichromatic in daylight — seeing two primary colours rather than the three that most humans see.

However, it also discovered that snake visual pigment genes have undergone a great amount of adaptation, including many changes to the wavelengths of light that the pigments are sensitive to, in order to suit the diversity of lifestyles that snakes have evolved.

Most snakes examined in the new study are sensitive to UV light, which likely allows them to see well in low light conditions. For light to reach the retina and be absorbed by the pigments, it first travels through the lens of the eye. Snakes with UV-sensitive visual pigments therefore have lenses that let UV light though.

In contrast, the research showed that those snakes that rely on their eyesight to hunt in the daytime, such as the gliding golden tree snake Chrysopelea ornata and the Monypellier snake Malpolon monspessulanus, have lenses that block UV light. As well as perhaps helping to protect their eyes from damage, this likely helps sharpen their sight — in the same way that skiers’ yellow goggles cut out some blue light and improve contrast.

Moreover, these snakes with UV-filtering lenses have tuned the pigments in their retina so that they are no longer sensitive to the short UV light, but absorb longer wavelengths.

All nocturnal species examined (such as N America’s glossy snake Arizona elegans) were found to have lenses that do not filter UV. Some snake species active in daylight also lack a UV-filtering lens, perhaps because they are less reliant on very sharp vision or live in places without very bright light.

By analysing how the pigments have evolved in snakes, the new study concluded also that the most recent ancestor of all living snakes had UV sensitive vision. “The precise nature of the ancestral snake is contentious, but the evidence from vision is consistent with the idea that it was adapted to living in low light conditions on land,” said corresponding author Gower.

https://www.sciencedaily.com/  Science Daily

https://www.sciencedaily.com/releases/2016/08/160816182620.htm  Original web page at Science Daily

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How chameleons capture their prey

Despite their nonchalant appearance, chameleons are formidable predators, capturing their prey by whipping out their tongues with incredible precision. They can even capture preys weighing up to 30% of their own weight. In collaboration with the Muséum national d’Histoire naturelle de Paris, researchers from the Université de Mons (UMONS) and the Université libre de Bruxelles (ULB) have studied this amazing sticky weapon.

Chameleons are fascinating creatures with amazing characteristics. Their feet have opposable toes, giving them a tongs-like appearance, to firmly grip branches. Their eyes move independently of each other to provide 360 degree vision. Their skin changes colour via the active tuning of a lattice of nanocrystals contained in some cells. But their most outstanding characteristic is probably their ballistic tongue, allowing the capture of distant preys.

Despite their nonchalant appearance, chameleons are formidable predators, leaving little chance to their prey. During a capture, their tongue whips out with an acceleration up to 1500 m/s² and extends to reach a length twice that of the chameleon’s body. They are also able to capture preys weighing up to 30% of their own weight. Sufficient adhesion between the prey and the tongue is therefore necessary to catch such preys.

Under the leadership of Fabian Brau from the ULB Faculty of Science’s Nonlinear Physical Chemistry Unit, Pascal Damman from the UMONS Interfaces and Complex Fluids Laboratory, Faculty of Science researchers from the UMONS, ULB, and Vincent Bels from the Muséum national d’Histoire naturelle de Paris have just demonstrated that the mucus secreted at the tip of a chameleon’s tongue has a viscosity 400 times larger than the one of human saliva. The tongue’s deformability during projection, producing a large contact area with the prey, together with this viscous liquid, form a particularly efficient adhesive weapon.

Published in the Nature Physics journal on 20 June, this interdisciplinary study, combining experiments with a dynamical model of prey capture, allowed the researchers to shed light on the basic mechanisms used by chameleons to capture their preys.

The authors used mechanical tools combined with tongue morphology measurements to demonstrate that the viscous adhesion built up during a capture is large enough to catch preys with a high mass compared to that of chameleons. Their theoretical model compares favourably with experimental data on the maximum prey mass with respect to the chameleon size.

These results provide a new methodology for studying prey prehension by other predators, such as salamanders or toads, using the tongue to capture preys.

https://www.sciencedaily.com/ Science Daily

https://www.sciencedaily.com/releases/2016/06/160621115647.htm  Original web page at Science Daily

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Human-eating monster crocodile may be Florida’s newest invasive species

Spotting native alligators and crocodiles in Florida is common, but anyone who sees a large reptile may want to take a second look — human-eaters that can grow to 18 feet long and weigh as much as a small car have been found in the Sunshine State.

Using DNA analysis, University of Florida researchers have confirmed the capture of multiple Nile crocodiles in the wild.

The ancient icon eats everything from zebras to small hippos to humans in sub-Saharan Africa. Now three juveniles of the monster crocodile, have been found in South Florida, swimming in the Everglades and relaxing on a house porch in Miami.

The invasive crocodiles were captured between 2000 and 2014, leading UF scientists to analyze their DNA, study their diet and one of the animal’s growth. Scientists verified the animals were Nile crocodiles linked to native populations in South Africa, and confirmed the species can survive in Florida — and potentially thrive, said Kenneth Krysko, herpetology collections manager at the Florida Museum of Natural History on the UF campus.

“The odds that the few of us who study Florida reptiles have found all of the Nile crocs out there is probably unlikely,” said Krysko, co-author of the study published in April in the Journal of Herpetological Conservation and Biology. “We know that they can survive in the Florida wilderness for numerous years, we know that they grow quickly here and we know their behavior in their native range, and there is no reason to suggest that would change here in Florida.”

Nile crocodiles, Crocodylus niloticus, were responsible for at least 480 attacks on people and 123 fatalities in Africa between 2010 and 2014. They are generalist predators and eat a wide variety of prey. In Florida, everything from native birds, fish and mammals to the state’s native crocodile and alligator would be fair game for the carnivorous croc.

The study found one juvenile grew nearly 28 percent faster than wild Nile crocodile juveniles from some parts of their native range. DNA analysis revealed the three similar-size Nile crocodiles were genetically identical, suggesting they were introduced via the same source, but Krysko said the source has not been confirmed. Prior to graduating in 2013, former UF doctoral student and co-author Matthew Shirley extensively sampled DNA of live Nile crocodiles housed in U.S. zoos, including Florida. The DNA of the three crocodiles did not match any of those Shirley sampled, suggesting they were either acquired by a permitted source later, or introduced by someone without a permit.

Study scientists note that over the last decade, large groups of Nile crocodiles have been imported from South Africa and Madagascar for display at places like Disney’s Animal Kingdom and to supply Florida’s flourishing pet trade, with the latter being the most likely introduction pathway, according to the study.

While there is currently no evidence of an established population, study scientists recommend a scientific risk assessment to evaluate the potential for Nile crocodiles to breed and spread across the state. According to the study, Florida’s Atlantic coast and the entire Gulf of Mexico coastline provide favorable climate for Nile crocodiles.

Florida’s subtropical climate is one reason the state has the world’s largest number of invasive species — from the Burmese python that has invested the Everglades to the Cuban tree frog, which has been found as far north as Jacksonville on the East Coast and as far north as Cedar Key on the Gulf Coast.

“My hope as a biologist is that the introduction of Nile crocodiles in Florida opens everyone’s eyes to the problem of invasive species that we have here in our state,” Krysko said. “Now here’s another one, but this time it isn’t just a tiny house gecko from Africa.”

https://www.sciencedaily.com/  Science Daily

https://www.sciencedaily.com/releases/2016/05/160520102244.htm  Original web page at Science Daily

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Top 10 new species for 2016

A hominid in the same genus as humans and an ape nicknamed “Laia” that might provide clues to the origin of humans are among the discoveries identified by the SUNY College of Environmental Science and Forestry (ESF) as the Top 10 New Species for 2016.

The list also includes a new kind of giant Galapagos tortoise, which could serve as a poster species for conservation and evolution, and two fish — a seadragon in stunning shades of ruby red and pink and, conversely, an anglerfish that would not win an undersea beauty pageant.

Rounding out this year’s Top 10 are three invertebrates — a tiny isopod that builds its own mud shelters, a beetle named after a fictional bear who traveled from Peru to London and a damselfly with a suggestive name, and two plants — a carnivorous sundew that was considered endangered as soon as it was found and a tree that was hiding in plain sight.

Brazil and Gabon each contributed two new additions to the planet’s biodiversity. The others hail from Ecuador, South Africa, the Gulf of Mexico, Australia, Spain and Peru.

The list is compiled annually by ESF’s International Institute for Species Exploration (IISE). The institute’s international committee of taxonomists selects the Top 10 from among the approximately 18,000 new species named during the previous year. The list is made public around May 23 to recognize the birthday of Carolus Linnaeus, an 18th century Swedish botanist who is considered the father of modern taxonomy.

Established in 2008, the list calls attention to discoveries that are made even as species are going extinct faster than they are being identified. “In the past half-century we have come to recognize that species are going extinct at an alarming rate. It is time that we accelerate species exploration, too. Knowledge of what species exist, where they live, and what they do will help mitigate the biodiversity crisis and archive evidence of the life on our planet that does disappear in the wild,” said Dr. Quentin Wheeler, ESF president and founding director of the IISE.

Scientists believe 10 million species await discovery, five times the number that are already known to science. “The rate of description of species is effectively unchanged since before World War II. The result is that species are disappearing at a rate at least equal to that of their discovery. We can only win this race to explore biodiversity if we pick up the pace. In so doing we gather irreplaceable evidence of our origins, discover clues to more efficient and sustainable ways to meet human needs, and arm ourselves with fundamental knowledge essential for wide-scale conservation success,” Wheeler said.

One of the 2016 Top 10 New Species

Giant Tortoise: 185 Years Post-Darwin, a New Species in Galapagos

Chelonoidis donfaustoi

Location: Galapagos, Ecuador

How it made the Top 10: No animals are more immediately associated with evolution or Charles Darwin than the giant tortoises of the Galapagos. Small differences had been noticed between eastern and western populations of giant tortoises on Santa Cruz Island that were assumed to be simply genetic variation within the known species, C. porteri. A careful analysis of both genetic and morphological data, however, shows that the smaller eastern population, with perhaps as few as 250 individuals, is a distinct and new species. This discovery has immediate, important conservation implications. C. porteri has a more limited geographic range than previously believed, restricted to western and southwestern areas of the island, and care must be taken to avoid bridging the natural isolation of the two species. The new species was named in honor of a park ranger known as “Don Fausto,” who worked 43 years to conserve the giant tortoises of Galapagos.

https://www.sciencedaily.com/  Science Daily

https://www.sciencedaily.com/releases/2016/05/160523084301.htm  Original web page at Science Daily

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Mammal-like reptile survived much longer than thought

Teeth can reveal a lot, such as how the earliest mammals lived with their neighbors. Researchers have uncovered dozens of fossilized teeth in Kuwajima, Japan and identified this as a new species of tritylodontid, an animal family that links the evolution of mammals from reptiles. This finding suggests that tritylodontids co-existed with some of the earliest mammal species for millions of years, overturning beliefs that mammals wiped out mammal-like reptiles soon after they emerged.

Tritylodontids are the last known family of near-mammalian reptiles, before mammals with features such as advanced hearing evolved.

“Tritylodontids were herbivores with unique sets of teeth which intersect when they bite,” explains study author Hiroshige Matsuoka, based at Kyoto University. “They had pretty much the same features as mammals — for instance they were most likely warm-blooded — but taxonomically speaking they were reptiles, because in their jaws they still had a bone that in mammals is used for hearing.”

While excavating a geologic layer from the Cretaceous era in Kuwajima, researchers found fossils of dinosaurs, turtles, lizards, fish, many types of plants, and Mesozoic mammals. Among these were more than 250 tritylodontid teeth, the first to be found in Japan.

Tritylodontids lived in the Jurassic era and proliferated worldwide, but were thought to have died out as herbivorous mammals took over their ecological role in the late Jurassic. “This made sense, because otherwise tritylodontids and the herbivorous mammals would have competed for the same niche,” says Matsuoka.

But according to the team’s finding, trytylodontids seem to have survived at least 30 million years longer than what paleontologists had believed.

“This raises new questions about how tritylodontids and their mammalian neighbors shared or separated ecological roles,” says Matsuoka.

The study is also the first of its kind to depend solely on details from teeth to determine whether the species is new, and also where it sits on the evolutionary tree.

“Usually fossils are identified as a new species only when a relatively complete set of structures like a jaw bone are found. In these cases, characteristics of teeth tend to be described only briefly,” adds Matsuoka. “Tritylodontid teeth have three rows of 2-3 cusps. This time we paid attention to fine details like the size and shape of each cusp. By using this method it should be possible to characterize other species on the evolutionary tree as well.”

“Because fossils of so many diverse families of animals are to be found in Kuwajima, we’d like to keep investigating the site to uncover things not just about individual species, but also about entire ecological dynamics.”

https://www.sciencedaily.com/  Science Daily

https://www.sciencedaily.com/releases/2016/04/160425112655.htm  Original web page at Science Daily

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Tunnel through the head: Internally coupled ears enable directional hearing in animals

Humans use the time delay between the arrival of a sound wave at each ear to discern the direction of the source. In frogs, lizards and birds the distance between the ears is too small. However, they have a cavity connecting the eardrums, in which internal and external sound waves are superimposed. Using a universal mathematical model, researchers at the Technical University of Munich (TUM) have now for the first time shown how new signals are created in this “inner ear” used by animals for localizing sounds.

Whether perceiving an encroaching predator or finding prey in the dark, precisely localizing the source of a sound is indispensable in the animal kingdom. Almost all mammals, including humans, localize sound sources horizontally via the the delay in time in which sound signals arrive at each ear. Using this time difference the brain can calculate the direction from which the sound emanated.

Frogs, many reptiles and birds do not have this option since the distance between their ears often measures merely a few centimeters. The time difference is thus so small that it cannot be processed by the brain. To make up for this disadvantage theses animals have developed a simple albeit very effective system: An air-filled cavity connects the eardrums of the two ears.

This cavity, which runs right through the head, couples the eardrums. The scientists refer to this as “internally coupled ears” or ICE. This “tunnel in the head” is clearly visible when light falls into one ear of a gecko: The light then shines out of the other ear.

Unlike humans, the animals perceive not only external signals, but also a superposition of external sound waves with those that are created internally through the coupling of the two sides. Scientists have determined in experiments that animals use the resulting signals for pinpointing sound sources. But what exactly happens in the coupled ears remained a mystery.

Now, scientists working led by Leo van Hemmen, Professor of Theoretical Biophysics at the Technical University of Munich (TUM) have for the first time developed an universal mathematical model that describes how sound waves propagate through the internally coupled ears and which clues for localizing sound sources are created in the process.

“Our model is applicable to all animals with this kind of hearing system, regardless that the cavities between the eardrums of the various species look very different,” explains van Hemmen. “We now understand what exactly happens inside the ears of these animals and can both explain and predict the results of experiments in all sorts of animals.” Over 15,000 species have internally coupled ears — that is more than half of all land-dwelling vertebrate animals.

Using their model, van Hemmen and his team discovered that the animals have even developed two different methods of hearing with internally coupled ears. They occur in different frequency domains and augment each other.

In sounds below the fundamental frequency of the eardrum the time difference in the superposition of the internal and external signals is amplified up to five-fold. That is sufficient to facilitate sound localization.

In higher frequencies the time difference can no longer be evaluated. Here, another property of the signal becomes relevant: The difference in the amplitude, i.e. the loudness, of the sound perceived by the ears. “The amplitude difference occurs solely through the coupling of the two ears,” explains van Hemmen. “That was a surprising result.”

This new insight on the mechanisms and especially the advantages of hearing with internally coupled ears is also relevant for industrial applications. It is conceivable that robots will be equipped with this kind of hearing system. “I can very well imagine applications in robotics, because this kind of amplification doesn’t need energy” expresses van Hemmen. In the future van Hemmen and his team of scientists hope to refine their model in collaboration with the experimental work of colleagues.

https://www.sciencedaily.com/ Science Daily

https://www.sciencedaily.com/releases/2016/02/160218133146.htm  Original web page at Science Daily

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Attention: Terrapin! Invasive pond slider on the move

Using genetic methods, scientists of the Senckenberg Research Institute in Dresden discovered that the introduced pond slider is capable of reproducing in Europe even outside of the Mediterranean region. The turtle, originally from North America, poses a significant threat to the native turtle fauna and, according to the authors of the study recently published in the scientific journal “Conservation Genetics,” should be intercepted in Europe.

The pond slider (Trachemys scripta) is the world’s most widely distributed species beyond its native range. These turtles with a shell length of up to 30 centimeters are native to the Southeastern U.S. – but today, they are found on all continents, except for Antarctica and a few oceanic islands. “The turtle can be found in the wild in practically all European countries.” explains Dr. Melita Vamberger of the Senckenberg Natural History Collections in Dresden, and she continues, “These reptiles owe their wide-spread distribution to the captive animal trade.”

The species is considered a threat to native turtles, since it is in direct competition with them regarding food as well as nesting and basking sites. Moreover, the introduced reptiles are potential carriers of parasites and other pathogens. Since the 1990s, the import of these popular pets with their vividly orange to red head stripes has been outlawed in Europe. “However, in some countries, in particular in the Balkan states, the illegal trade continues to flourish,” adds Vamberger, and she goes on to say, “But for a long time, it was not clear whether the species could become invasive in Europe.” Until now, the successful reproduction and establishment of these animals had only been documented in the Mediterranean region.

The Slovenian-German team of researchers around Dr. Vamberger and the director of Senckenberg Dresden, Professor Dr. Uwe Fritz has now been able to demonstrate by means of genetic studies that the turtles also reproduce in Slovenia. The biologists took samples of 77 turtles from three sites and could show that they reproduce in all areas examined in Slovenia. “We selected the sites based on climatic differences,” explains Fritz, and he adds, “Unfortunately, the pond slider also reproduce and spread in the vicinity of Ljubljana – a temperate, continental climate.”

For the first time, the researchers were thus able to offer genetic proof that Trachemys scripta can also reproduce outside the Mediterranean region with its mild climate. Around Ljubljana, the capital of Slovenia, fewer animals were found that were related to each other than in the warmer regions, which could indicate that the turtles reproduce less frequently here. “However, it is likely that more animals with new genetic material are being released near the city, which necessarily leads to fewer related animals,” cautions Vamberger.

Due to the potential for expansion beyond the Mediterranean region and the potential threat to native species, the sliders should be classified as invasive, according to the biologists from Dresden. “In addition, we recommend to intercept the pond slider, at least in habitats occupied by native turtle species, in order to prevent the spread of the invasive turtle and the displacement of the native inhabitants,” says Fritz in closing.

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2016/01/160122122729.htm  Original web page at Science Daily

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Tiniest chameleons deliver most powerful tongue-lashings

Chameleons are known for sticking their tongues out at the world fast and far, but until a new study by Brown University biologist Christopher Anderson, the true extent of this awesome capability had been largely overlooked. That’s because the smallest species hadn’t been measured.

“Smaller species have higher performance than larger species,” said Anderson, a postdoctoral research associate in the Department of Ecology and Evolutionary Biology.

In Scientific Reports, Anderson shows that ballistic tongue projection in a chameleon that would fit on your thumb produced a peak acceleration 264 times greater than the acceleration due to gravity. In automotive terms, the tongue could go from 0 to 60 miles per hour in a hundredth of a second, though it only needs about 20 milliseconds to snag a cricket.

Anderson’s review of the biomechanics literature suggests that the motion has the highest acceleration and power output produced per kilogram of muscle mass by any reptile, bird, or mammal and is the second most powerful among any kind of vertebrate (only a salamander outdoes it). The total power output of the plucky Rhampholeon spinosus chameleon’s tongue was 14,040 watts per kilogram.

The secret of chameleons is that they don’t just use spontaneous muscle power to fling their tongues. They preload most of the motion’s total energy into elastic tissues in their tongue. The recoil of those tissues greatly augments what muscle alone can do on the fly — to catch a fly.

Anderson wanted to find the upper limit of chameleon tongue performance. To do that, he gathered individuals of 20 species of widely varying sizes in his former University of South Florida lab. Then he perched them one by one in front of a camera that shoots 3,000 frames a second. For each measurement, a cricket hung off a small dangling mesh to tempt the tongue to emerge. When it did, he could measure the distance the tongue went, the elapsed time, and the speed and the acceleration at any given time.

What Anderson noticed across all his measurements and analysis was that the smaller the chameleon, the higher the peak acceleration, relative power, and distance of tongue extension relative to body size (Rhampholeon spinosus stuck out its tongue to 2.5 times its body length). Larger chameleons produced impressive motions, too, but not compared to their smaller cousins. For example, a roughly two-foot-long species, Furcifer oustaleti, managed a peak acceleration less than 18 percent that of the tiny champ, Rhamp.

The results make physical and evolutionary sense, Anderson said. All of the chameleons have the same catapult-like apparatus for launching the tongue, but proportional to their size, smaller chameleons have a bigger one than larger chameleons. They are like little sports cars with relatively powerful engines.

The evolutionary reason why tiny chameleons are proportionately better equipped for feeding is presumed to be because, like all small animals, they need to consume more energy per body weight to survive. So little chameleons must be especially good at catching their insect meals — their tongues have to burst out unusually fast and far to compete for all that needed nutrition.

For these reasons, Anderson said, it will often benefit researchers to look at the little guys when studying physical performance. Prior studies of chameleon tongue acceleration had measured much lower peak values because they only looked at much larger chameleons.

“What this study shows is that by using smaller species, we may be able to elucidate these higher performance values,” he said.

http://www.sciencedaily.com/   Science Daily

http://www.sciencedaily.com/releases/2016/01/160104080020.htm  Original web page at Science Daily

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Marine airgun noise could cause turtle trauma

Scientists from the University of Exeter are warning of the risks that seismic surveys may pose to sea turtles. Widely used in marine oil and gas exploration, seismic surveys use airguns to produce sound waves that penetrate the sea floor to map oil and gas reserves.

The review, published in the journal Biological Conservation, found that compared to marine mammals and fish, turtles are largely ignored in terms of research attention and are often omitted from policy guidelines designed to mitigate the environmental risks of seismic surveys.

Possible ramifications for turtles include behavioural changes and exclusion from critical habitats as well as potential auditory damage, as turtle hearing ranges overlap with airgun frequencies. In addition, turtles are known to become entangled in gear towed behind the survey vessel, which can lead to drowning.

Lead author Sarah Nelms from the Centre for Ecology and Conservation at the University of Exeter’s Penryn Campus in Cornwall said: “By talking to oil and gas companies, seismic operators and on-board Marine Mammal Observers, as well as academics and conservationists, we had a great opportunity to gather a broad spectrum of opinions, not just one side of the story. This allowed us to access information that was not available in the published literature.”

The researchers also examined policy guidelines for the mitigation of risk to marine life in seismic surveys and assessed peer-reviewed literature on the topic.

“Our study reveals the potential for seismic surveys to cause behavioural changes and physical harm to turtles and we are calling for more research to urgently fill the crucial knowledge gaps that were highlighted during our review,” said Ms Nelms.

During a survey, specialised ships simultaneously fire multiple airguns while towing multiple hydrophone streamers, which can cover an area up to 700m wide and 12km long, to capture the returning sound waves. Researchers involved in the study received reports of turtles becoming entangled in the trailing tail buoys and developed a turtle guard which has been voluntarily installed by some operators. Further research could help make such preventative measures mandatory in the future.

Senior author Professor Brendan Godley, also from the University of Exeter’s Centre for Ecology and Conservation, said: “Seismic surveys are occurring in the waters of at least 50 countries in which marine turtles are present and they are becoming increasingly widespread. Given the conservation status of turtles, we feel that it is important and timely to assess the level of threat posed by this global activity and highlight knowledge gaps to direct future research efforts.”

“There is a great deal that could be done proactively to help improve the status quo. We are standing by to work with seismic companies and others in the oil and gas sector to this end.”

The researchers hope that their findings will assist with the development of policies to minimise the impact of seismic surveys on marine turtle populations, for example ensuring that they are not carried out during sensitive times or in critical areas, such as during breeding seasons or in foraging grounds.

http://www.sciencedaily.com/   Science Daily

http://www.sciencedaily.com/releases/2015/11/151123101905.htm  Original web page at Science Daily

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Illegal trade of Indian star tortoises is a far graver issue

Patterned with star-like figures on their shells, Indian star tortoises can be found in private homes across Asia, where they are commonly kept as pets. One can also see them in religious temples, praised as the living incarnation of the Hindu god Vishnu. How did they get there? Suspicious of a large-scale illegal international trade of these tortoises that could in fact pose a grave threat to the survival of the Indian Star tortoise, a team of researchers, led by Dr. Neil D’Cruze from Wildlife Conservation Research Unit, University of Oxford, and World Animal Protection, London, spent 17 months investigating the case focusing on India and Thailand. They have their study published in the open-access journal Nature Conservation.

The present study established that at least 55,000 Indian star tortoise individuals are being poached over the span of a year from a single trade hub in India. Helped by a number of herpetologists and wildlife enforcement officials, the researchers have tracked signals about how sophisticated criminal gangs are exploiting “legal loopholes” and people alike, taking advantage of rural communities and urban consumers in India and other Asian countries.

“We were shocked at the sheer scale of the illegal trade in tortoises and the cruelty inflicted upon them,” comments Dr. Neil D’Cruze. “Over 15 years ago wildlife experts warned that the domestic trade in Indian star tortoises needed to be contained before it could become established as an organised international criminal operation.”

“Unfortunately, it seems that our worst nightmare has come true — sophisticated criminal gangs are exploiting both impoverished rural communities and urban consumers alike,” he also added. “Neither group is fully aware how their actions are threatening the welfare and conservation of these tortoises.”

Although deemed of “Least Concern” on the IUCN Red List when last formally assessed back in 2000, the Indian star tortoise and its increasing illegal poaching and trading can easily lead to a serious risk of the species’ extinction. Other dangers of such unregulated activities include the introduction of invasive species and diseases.

Having spent a year among a rural hunter-gatherer community, researchers established the collection of at least 55,000 juvenile wild Indian star tortoises between January and December 2014. This is already between three and six times more than the last such record dating from about ten years ago.

Collectors tend to poach juvenile tortoises, but it is not rare for them to also catch adults. Based on the individual’s age and health, the tortoises are later sold to vendors at a price of between 50 and 300 Indian Rupees (INR), or between 1 and 5 USD, per animal. “Therefore, we conservatively estimate (assuming no mortalities) that the collector engagement in this illegal operation has a collective annual value of up to 16,500,000 INR (263,000 USD) for their impoverished communities,” comment the researchers.

Consumers seek the Indian star tortoise for either exotic pets or spiritual purposes. With their star-like radiating yellow patterns splashed with black on their shells, not only is this tortoise species an attractive animal, but it was also found to be considered as a good omen among the locals in the Indian state of Gujarat. During their survey, the researchers found over a hundred hatchlings in a single urban household. However, their owner claimed that none of them was kept with commercial intent, although some of the tortoises were meant for close friends and relatives.

On the other hand, there was a case where the researchers came across a Shiva temple hosting a total of eleven Indian star tortoises. Temple representatives there confirmed that the tortoise is believed to represent an incarnation of the Hindu god Vishnu, one of the three central gods in the religion, recognised as the preserver and protector of the universe.

In India vendors do not show the reptiles in public, but they are made available upon a special request. If paid for in advance, a vendor can also supply a larger quantity of the animals at a price ranging from 1,000 to 3,000 INR (15 to 50 USD) per animal. The researchers managed to see seven captive tortoises in private, including six juveniles and one adult, all in visibly poor health. Disturbingly, in order to reach these vendors, the collected tortoise are usually wrapped in cloths and packed into suitcases. Covered by a ‘mask’ of legal produce such as fruit and vegetables, they are transported to the ‘trade hubs’. They are also smuggled abroad to satisfy consumer demand among the growing middle classes in countries such as Thailand and China.

“Despite being protected in India since the 1970’s, legal ‘loopholes’ in other Asian countries such as Thailand and China appear to undermine India’s enforcement efforts,” explains Mr. Gajender Sharma, India’s Director at World Animal Protection, “They are smuggled out of the country in confined spaces, it’s clear there is little or no concern about the welfare of these reptiles.”

“World Animal Protection is concerned about the suffering that these tortoises endure,” he further notes. “We are dealing with an organised international criminal operation which requires an equally organised international approach to combat it.

As a result of their study, the authors conclude that more research into both the illegal trafficking of Indian star tortoise and its effects as well as the consumer demand is urgently needed in order to assess, address and subsequently tackle the issue.

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2015/11/151109103728.htm  Original web page at Science Daily

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Genetics probe identifies new Galapagos tortoise species

The tortoise Chelonoidis donfaustoi is found on Santa Cruz island in Ecuador. A new species of giant tortoise has been discovered hiding in plain sight on Ecuador’s Galapagos Islands. A population of about 250 animals living in an arid inland area of Santa Cruz island turns out to be so genetically distinct from the rest of the island’s tortoises that researchers have determined that it represents a separate species: Chelonoidis donfaustoi.

The designation may lead to more intense protection of the new species. Its range is partly protected, but the new species designation may spur efforts to stop agriculture from nibbling away at the unprotected portions of the tortoise’s home turf.

The species name, donfaustoi, honours former Galapagos National Park ranger Fausto Llerena Sánchez, known to his friends and colleagues as Don Fausto. Don Fausto, who managed the captive breeding programme for tortoises at the park, retired last year after 43 years of service.

“This guy dedicated his life to them,” says Adalgisa Caccone, an evolutionary biologist at Yale University in New Haven, Connecticut, and the lead author of the paper describing the species. “All the other [tortoise] species are named by scientists for scientists or explorers, but no species has been named after a person from Ecuador.”

Caccone and her colleagues had suspected for at least ten years that the inland tortoises, which inhabit an area about 20 kilometres from the main population, might be a separate species. The theory was first suggested by wildlife biologist Tom Fritts, who is now retired from the US Geological Survey.

Fritts says that it was the clear geographical separation between the two populations that intrigued him, rather than any differences in appearance, or morphology. “Adult tortoises wear their history on their backs,” he says “There is a great deal of variation produced by environmental effect, so it is very difficult to differentiate them based on morphology.”

So he suggested that Caccone’s team investigate the genetics of the two populations. Their paper, published in PLoS ONE on 21 October, is the culmination of a decade of work. It presents 25 mitochondrial DNA mutations that reliably separate the two groups.

The researchers also analyzed 12 highly variable regions of nuclear DNA called microsatellite loci in 51 tortoises from both groups. The team found that when these loci were plotted by their distinctness from one another, two clear clusters emerged that corresponded to the two tortoise populations. “They are very distinct,” Caccone says.

The team has built a family tree of the islands’ tortoises using thousands of samples collected in the past 20 years, allowing them to investigate the history of the two Santa Cruz species. The closest relatives of C. donfaustoi live on another island altogether, San Cristóbal. “Santa Cruz was colonized two times independently,” Caccone says.

Michel Milinkovitch, a conservation geneticist at the University of Geneva in Switzerland who has worked on Galapagos tortoises, says that the analysis shows that the groups are just as distinct as other tortoises in the archipelago that are considered separate species. (With the new discovery, the Galapagos is home to 12 known giant tortoise species.)

But whether the tortoise is a new species or perhaps just a subspecies matters less to him than its status as a genetically distinct breeding population. “The species concept is a fuzzy one,” he says. “Call them whatever you want, I don’t care. What is important is that people realize there is hidden diversity.”

Nature doi:10.1038/nature.2015.18611

http://www.nature.com/news/index.html   Nature

http://www.nature.com/news/genetics-probe-identifies-new-galapagos-tortoise-species-1.18611  Original web page at Nature

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* Climate change threatens survival of common lizards

While there is no doubt that climate change is affecting many organisms, some species might be more sensitive than others. Reptiles, whose body temperature depends directly on environmental temperature, may be particularly vulnerable. Scientists have now shown experimentally that lizards cope very poorly with the climate predicted for the year 2100.

In a new study, publishing in the Open Access journal PLOS Biology on October 26th, Elvire Bestion, Julien Cote and colleagues examined the consequences of a 2°C warmer climate on the persistence of populations of common lizards (Zootoca vivipara), a widespread European reptile. Their results show that many common lizard populations could disappear rapidly as a consequence of such warmer temperatures.

“Breed fast and die young” seems to be the new mantra of common lizards in the face of climate change; it is also the conclusion reached by researchers from the Station d’écologie expérimentale du CNRS à Moulis (SEEM) and the Laboratoire Evolution et Diversité Biologique (EDB, CNRS/Université Toulouse 3 Paul Sabatier/ENFA) who studied this small European reptile species.

The team used the Metatron — a system of semi-natural enclosures in which temperature can be manipulated — to create two distinct climates: one similar to the present climate and another 2 °C warmer, corresponding to the predicted climate for the end of the century. Eighteen populations of common lizards were put into Metatron enclosures over two years in the “present” or “warmed” climate. Populations were surveyed for one year, allowing the team to determine the impact of warmer climates on demographic parameters such as growth rate, reproduction and survival.

“While a two-degrees warmer climate might seem beneficial at first, as it leads to faster growth of juvenile lizards and earlier access to reproduction, it also leads to lower survival in adult individuals, which should endanger population survival,” says Elvire Bestion, co-lead author of the study and currently working at Exeter University (United Kingdom). A model of population dynamics showed that the increased adult mortality would lead to decreased population growth rates, and ultimately to rapid population extinctions in around 20 years.

“Although these results might seem dramatic, we do not predict extinction of common lizards at the scale of the species, but we suggest that populations at the southern edge of their range of distribution might particularly suffer from warmer climates,” adds Julien Cote, biologist at the Laboratoire Evolution et Diversité Biologique (France) and co-lead author of the study. Indeed, comparisons of experimental conditions to climatic conditions encountered by European populations of common lizards show that warmer climates might threaten between 14 and 30 % of European populations depending on the carbon emission scenario.

“Anecdotally, we also showed that warmer climates led some adult females to engage into a second reproduction event during the summer, while these lizards normally reproduce only once a year during the spring. Combined with the earlier juvenile reproduction and the higher adult survival, these results suggest a shift of demographic strategy from a relatively long life and low reproductive output to a faster life, higher reproductive investment. We can wonder whether this strategy shift may help adaptation of populations to warmer climates over time,” concludes Elvire Bestion, adding a positive note to overall pessimistic results.

http://www.sciencedaily.com/ Science Daily

http://www.sciencedaily.com/releases/2015/10/151026172109.htm  Original web page at Science Daily

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* Reptile pets: Food insects shuttle allergens into homes

Reptiles are often chosen as pets when an allergy risk exists within a family and the choice is made to avoid potentially allergenic pets such as dogs, cats or guinea pigs. Researchers at the Messerli Research Institute, however, recently described a noteworthy clinical case in which an eight-year-old boy developed nightly attacks of severe shortness of breath four months after the purchase of a bearded dragon.

The cause for the allergic reaction turned out not to be the lizard itself but the animal’s food. The grasshoppers used to regularly feed the lizard were revealed to be the source of the allergy.

First author Erika Jensen-Jarolim speaks of the tip of an iceberg: “Even colleagues with allergologic expertise could overlook insects as reptile food as a possible cause of such allergic reactions. Far too little is known about grasshoppers as a potential allergenic source in homes. We do know of cases, however, in which fish food has caused allergies. And insects are often processed in fish food.”

For a long time, the cause of the allergic reaction in the eight-year-old Viennese boy remained unknown. The initial diagnosis was pseudo croup, an infection of the respiratory tract, and severe asthma. Allergy expert Jensen-Jarolim and her team considered the possibility of a pet allergy and chose to also test the reptile food: grasshoppers. An allergy skin test and evidence of specific IgE antibodies finally brought certainty: grasshopper allergens were the cause of the allergic reactions in the child.

“We were in the middle of a study investigating sources of allergies at pet stores. So coming upon the reptile food was pure coincidence,” says Jensen-Jarolim. On Jensen-Jarolim’s advice, the reptile was immediately removed from the boy’s home. The symptoms abated as a result. Four years later, however, the boy exposed himself to the allergen again, which triggered an allergic asthmatic reaction even after all that time.

“We are seeing a shift in the attitude towards reptiles from a pure hobby or biological interest toward a human-animal relationship with an emotional component. It is difficult to estimate the number of reptiles and food animals living in people’s homes and the undisclosed figure is sure to be high,” Jensen-Jarolim believes. She recommends keeping reptile food outside of homes. The reptiles themselves should not be kept in living rooms, as undigested insects end up in the terraria via the faeces. This could result in pet owners inhaling the aggressive allergens, leading to allergies such as asthma or skin inflammations.

“Grasshopper allergies have been nearly unknown to date. With our publication, it is our intention to sensitise the public to this matter. We are especially concerned about people who keep such animals, pet store employees as well as physicians, who should include questions regarding reptile pets and their food as a routine in their allergy diagnostic consultation,” stresses Jensen-Jarolim.

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2015/10/151030105252.htm  Original web page at Science Daily

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Sea turtles face plastic pollution peril

Study warns that all seven species of marine turtle can ingest or become entangled in discarded plastic debris. A new global review led by the University of Exeter that set out to investigate the hazards of marine plastic pollution has warned that all seven species of marine turtles can ingest or become entangled in the discarded debris that currently litters the oceans.

The research, which was carried out in collaboration with Plymouth Marine Laboratory, North Carolina Wildlife Resources Commission, North Carolina State University, Duke University Marine Lab and James Cook University, is published in the ICES Journal of Marine Science and reveals serious knowledge gaps in the diverse and complex pathways in which plastic pollution can harm marine life.

Joint lead author Sarah Nelms, from the Centre for Ecology and Conservation at the University of Exeter’s Penryn campus said: “I was shocked at how little is known about the impacts of plastic on marine turtles.”

“We know that discarded plastic poses a serious threat to wildlife, but this study shows that more research is urgently needed if we are to understand the scale of the problem.” Annual global plastic production has grown from 1.5 million tonnes to 299 million tonnes in the last 65 years and as a result plastic pollution is increasing, both on land and at sea.

Prof Brendan Godley, who led the team said: “When turtles ingest plastic, they can suffer intestinal blockage that can result in malnutrition which can in turn lead to poor health, reduced growth rates, lower reproductive output and even death.”

“It is sobering to think that almost every piece of plastic that ever entered the sea is still there; breaking down and forming a vast soup of microplastics that could have frightening long-term repercussions.” Entanglement in plastic debris, such as lost fishing gear or discarded packaging, can cause lacerations and increased drag when swimming, which may result in drowning or death by starvation.

Beach litter may also entangle nesting females or trap emerging hatchlings, while potentially affecting turtle nests by altering temperature and changing the permeability of the sediment on nesting beaches. The study demonstrates that urgent action is required to better understand this issue and its effects on marine turtles, so that appropriate and effective mitigation policies can be developed.

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2015/10/151009083023.htm  Original web page at Science Daily

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Sex and sea turtles: New study reveals impact of climate change, sea level rise

Marine turtles deposit their eggs in underground nests where they develop unattended and without parental care. Incubation temperature varies with environmental conditions, including rainfall, sun, shade and sand type, and affects developmental rates, hatch and emergence success, and embryonic sex. Although the loggerhead turtle has been around for more than 60 million years, drought, heavy rainfalls and climatic changes are impacting hatchling sex ratios and influencing future reproduction. Because sea turtles don’t have an X or Y chromosome, their sex is defined during development by the incubation environment. Warmer conditions produce females and cooler conditions produce males.

Researchers from Florida Atlantic University have just published the results of a four-year study in the journal Endangered Species Research, on the effects of turtle nest temperatures and sand temperatures and on hatchling seks.

“The shift in our climate is shifting turtles as well, because as the temperature of their nests change so do their reproduction patterns,” said Jeanette Wyneken, Ph.D., professor of biological sciences in FAU’s Charles E. Schmidt College of Science. “The nesting beaches along Florida’s coast are important, because they produce the majority of the loggerhead hatchlings entering the northwestern Atlantic Ocean.”

Loggerhead turtles are already fighting an uphill battle since roughly one in 2,500 to 7,000 sea turtles make it to adulthood. The typical loggerhead produces about 105 eggs per nesting season and would have to nest for more than 10 nesting seasons over the span of 20 to 30 years just to replace herself and possibly one mate. And, if enough males aren’t produced because of climate changes, then this will result in a dire problem for this species.

“If climatic changes continue to force the sex ratio bias of loggerheads to even greater extremes, we are going to lose the diversity of sea turtles as well as their overall ability to reproduce effectively. Sex ratios are already strongly female biased,” said Wyneken. “That’s why it’s critical to understand how environmental factors, specifically temperature and rainfall, influence hatchling sex ratios.”

Wyneken and her team documented rainfall and sand temperature relationships as well as rainfall, nest temperatures and hatchling sex ratios at a loggerhead turtle nesting beach in Boca Raton, located in southeast Florida. Nesting season, which runs from April through October, were sampled across 2010 and 2013. The researchers used temperature dataloggers in the sand at three locations and buried them at three different depths to create temperature profiles of the sand column above the level that would directly influence eggs. The rainfall data were graphed in temporal synchrony with sand temperature for each depth.

Nest temperatures were recorded throughout incubation. Rainfall data collected concurrently with sand temperatures at different depths showed that light rainfall affected only the surface sand; effects of the heaviest rainfall events tended to lower sand temperatures, however, the temperature fluctuations were very small once the moisture reached upper nest depths.

Nest temperature profiles were synchronized with rainfall data from weather services to identify relationships with hatchling sex ratios. The sex of each turtle was verified laparoscopically to provide empirical measures of sex ratios for the nest and the nesting beach.

“The majority of hatchlings in the sampling were female, suggesting that across the four seasons most nest temperatures were not sufficiently cool to produce males,” said Wyneken. “However, in the early portion of the nesting and in wet years, nest temperatures were cooler, and significantly more males hatched.”

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2015/10/151015111047.htm  Original web page at Science Daily

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Four-legged fossil snake is a world first

The first four-legged fossil snake ever found is forcing scientists to rethink how snakes evolved from lizards. Although it has four legs, Tetrapodophis amplectus has other features that clearly mark it as a snake, says Nick Longrich, a palaeontologist at the University of Bath, UK, and one of the authors of a paper describing the animal in Science.

The creature’s limbs were probably not used for locomotion, the researchers say, but rather for grasping prey, or perhaps for holding on to mating partners. Such speculation inspired the snake’s name, which loosely translates as ‘four-legged hugging snake’. Tetrapodophis was originally found in the fossil-rich Crato Formation in northeastern Brazil several decades ago. But its legs can be difficult to see at first glance, and it languished in a private collection after its discovery, assumed to be unremarkable.

“I was confident it might be a snake,” says David Martill, a palaeobiologist at the University of Portsmouth, UK, who came across the find in 2012. “It was only after getting the specimen under the microscope and looking at it in detail that my confidence grew. We had gone to see Archaeopteryx, the missing link between birds and dinosaurs, and discovered Tetrapodophis, the missing link between snakes and lizards.”

Scientists have long argued over whether snakes evolved from land or marine animals. Tetrapodophis lacks adaptations for marine life, such as a tail useful for swimming. But its skull and body proportions are consistent with adaptations for burrowing. Longrich says that the finding unequivocally shows that snakes originated in the Southern Hemisphere and strongly supports a terrestrial origin.

Another striking feature of the fossil is its relative length. Tetrapodophis has 272 vertebrae, 160 of which are in its main body, not its tail. This number is more than twice the limit that researchers thought elongated bodies could reach before starting to lose their limbs.

Martin Cohn, an evolutionary developmental biologist at the University of Florida, Gainesville, says that the animal’s limbs must have been repurposed by evolution instead of simply dwindling away as its body became longer. This insight contradicts some assumptions about snake evolution. As Cohn explains, the paradigm about elongation of the trunk leading to limb loss now has to be adjusted. “This fossil shows that the two processes can be decoupled,” he says.

The discovery comes in a major year for snake evolution research, Cohn says. In January, the snake fossil record was pushed back by some 70 million years to the Middle Jurassic, around 160 million years ago, with the report of the oldest snake ever found. Although Tetrapodophis is not the oldest snake, Cohn says, “from a developmental perspective, this could be one of the most important fossils ever found. The combination of a snake-like body with complete forelimbs and hindlimbs is like a snake version of Archaeopteryx.”

Nature doi:10.1038/nature.2015.18050

http://www.nature.com/news/index.html Nature

http://www.nature.com/news/four-legged-fossil-snake-is-a-world-first-1.18050 Original web page at Nature

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* First artificial insemination of Yangtze giant softshell turtle

A female Yangtze giant softshell turtle (Rafetus swinhoei) — potentially the last female of her species — has been artificially inseminated. The procedure, which brought together top scientists from China, Australia and the United States, provides a ray of hope in a continuing effort to save the world’s most endangered turtle.

The pair at the Suzhou Zoo in China, were brought together as part of a breeding program in 2008. With natural breeding unsuccessful, scientists recently artificially inseminated the female with the male’s sperm. The Turtle Survival Alliance (TSA), San Diego Zoo Global and WCS’s Bronx Zoo announced that working in conjunction with Changsha Zoo, Suzhou Zoo and the China Zoo Association, a female Yangtze giant softshell turtle (Rafetus swinhoei) — potentially the last female of her species — has been artificially inseminated. The procedure, which brought together top scientists from China, Australia and the United States, provides a ray of hope in a continuing effort to save the world’s most endangered turtle.

There are four living Yangtze giant softshell turtles remaining in existence — two in Vietnam (both thought to be males) and two in China at the Suzhou Zoo (a male and female). The male and female — both believed to be greater than 100 years of age — were brought together in 2008 as part of a captive breeding program initiated by TSA and the WCS (Wildlife Conservation Society) China program. The female was transported from the Changsha Zoo to the Suzhou Zoo through the efforts of four partners (Changsha Zoo, Suzhou Zoo, TSA, and WCS).

WCS China Reptile Program Director and coordinator of the Rafetus swinhoei breeding program, Dr. Lu Shunqing, mediated the program agreement among the partners and has coordinated the program during the past 8 years. “It now appears that artificial insemination is the only possible option for the pair of Rafetus swinhoei in Suzhou Zoo to reproduce successfully,” said Dr.Lu Shunqing. “The fate of the most endangered softshell turtle of the world is now in the balance.”

Though the two turtles have before displayed courting behavior, eggs laid by the female have been infertile. “We had to find out if the last known male in China no longer produces viable sperm due to old age or an inability to inseminate the female,” said Dr. Gerald Kuchling, organizer of the artificial insemination effort and Rafetus breeding program leader for the TSA. To determine the cause of the infertility, Suzhou Zoo, Changsha Zoo, and the China Zoo Association requested TSA assemble a team of scientists to conduct a reproductive evaluation of the male, collect semen, determine if he had viable sperm, and, if viable sperm could be demonstrated, artificially inseminate the female.

“At first we tried semen collection through manual stimulation and the use of a vibrator, but as previously found in another softshell turtle, the only way was through sedation of the male and electro-ejaculation — risky procedures due to his old age,” Dr.Kuchling said.

During the process, the male was determined to have damaged sex organs, perhaps due to a fight with another male decades ago. For this reason, the scientists believe the male incapable of inseminating the female, and therefore, fertilizing the eggs.

Dr. Barbara Durrant, Director of Reproductive Physiology at the San Diego Zoo Institute for Conservation Research said, “Normal semen parameters for Rafetus are unknown as this was the first attempt to collect and examine sperm from this species. The semen evaluation revealed that approximately half of the sperm were motile.” Based on the results, it was determined the female could be artificially inseminated. This attempt marks the first time artificial insemination has been tried with any softshell turtle species and based on results of insemination with other turtles, the odds are not good for success. With natural breeding unsuccessful however, the scientists felt it was time to explore this option. Both turtles recovered from the procedure in good condition.

“The attempts to breed this critically endangered species, and overcome obstacles to natural breeding by this global consortium of experts is a great example of international cooperation to save endangered species,” said WCS Chief Veterinarian and Bronx-Zoo based Director of Zoological Health Dr. Paul P. Calle, who worked with Chinese veterinarians on the delicate sedation process. “We are grateful to our Chinese partners at the Suzhou Zoo, Changsha Zoo, and the China Zoo Association for inviting us to work with them in our collective attempt to save this species. ”

“This was a great exploration to advance the conservation of Rafetus swinhoei, however, we cannot yet determine if the exploration was successful or not,” said Director Chen Daqing of Suzhou Zoo. The female will lay the eggs in a few weeks and in a couple of weeks after that, the scientists will know if the eggs are fertile. Listed on the International Union for the Conservation of Nature’s Red List, the Yangtze giant softshell turtle is the most critically endangered turtle in the world. Its status in the wild has long been recognized as grim, but extinction risk now is believed higher than ever. Much of its demise has been attributed to over-harvesting and habitat degradation. Fort Worth Zoo Biologist and TSA President Rick Hudson said, “The conservation world will once again be holding its collective breath until we know if this was successful. The optimism we felt back in 2008 when the pair was mating and laying eggs has slowly faded as reality sank in that this pair would not breed without intervention.” “This autumn, the female Rafetus swinhoei will be moved back to Changsha Zoo. We hope some children move together with her,” said Vice Director Yan Xiahui of Changsha Zoo.

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2015/05/150527133716.htm  Original web page at Science Daily

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* World’s second most endangered turtle on road to recovery

WCS (Wildlife Conservation Society) and the Turtle Survival Alliance (TSA) announced that 60 captive-raised Myanmar roofed turtles — a species once thought extinct — have been released into their native habitat in Myanmar. More than 350 villagers, government representatives, and religious leaders attended ceremonies for the release. “This is the first chapter of a longer story yet to be written,” said WCS Regional Herpetologist Dr. Steven Platt during a release ceremony. “It’s one that will hopefully see the Myanmar roofed turtle restored as a functional member of this remote riverine landscape.” The Myanmar roofed turtle (Batagur trivittata) was believed extinct until 2001, when Dr. Steven Platt and U Win Ko Ko found a single shell from a recently killed turtle at a village along the Dokhtawady River. Subsequently, live individuals were discovered at a wildlife market in China and in the ponds of a pagoda in Mandalay. These turtles formed the nucleus of the captive assurance colony which was established under the supervision of Dr. Gerald Kuchling and WCS Veterinarian Dr. Tint Lwin.

This species is considered to be the second-most critically endangered turtle in the world due to the persistent threats of habitat loss, egg collection, and incidental catch by fishermen. Prior to the release, fewer than 10 adult females were surviving in the wild and were found only in a remote stretch of the Upper Chindwin River in Myanmar. In 2007, WCS and TSA began an ambitious program to “headstart” the species by collecting eggs from the wild to hatch, raise, and breed the turtles in captivity. This was done to eventually repopulate the turtles in their original habitat within and around the Htamanthi Wildlife Sanctuary. With the collaboration of the Myanmar Ministry of Environmental Conservation and Forestry, the program has been very successful, and the captive turtle population has grown notably in size. In 2011, a new facility was opened in Linpha Village in order to increase the program’s resilience to catastrophic events, and to bring the animals back closer to their natural habitat. The facility is now home to more than 300 turtles.

Younger turtles in the wild have very low survival rates due to natural predation by large fish, wading birds and monitor lizards. Only individuals large and strong enough to withstand such attacks, sizes that are attained around seven years of age, are deemed eligible for release. This year, WCS and TSA scientists selected 60 individuals suitable for reintroduction into the wild with an average carapace (upper shell) length of 25.3 cm. After undergoing health evaluations, including the use of molecular diagnostic techniques by WCS veterinarians, some of the animals to be released were equipped with a radio transmitter on their carapace. This will allow scientists to monitor the animals as they adapt to their wild habitat during the coming months. In addition, with the help of local residents, regular monitoring of turtle nesting areas will continue in the hopes of safeguarding eggs. The turtles were released on February 22 and February 27 in ceremonies in Linpha and Nam Thalet directly from the hands of local villagers, government officials, and Buddhist monks, who blessed the animals.

An additional 100 turtles were selected as suitable for relocation and were transported from Mandalay on a perilous 700 kilometer overland route to the facility in Htamanthi Village where they will be used to establish another captive-breeding colony. Kalyar Platt, Director of TSA-Myanmar said, “Conserving this species is not only beneficial for nature, but also crucially importantly for preserving the culture and traditions of the Khamti Shan ethnic group in Myanmar.” Traditionally, the Khamti Shan people who dwell along the Chindwin River have regarded turtles as an important food source, harvesting eggs each year in what they thought was a sustainable manner (a few eggs were left in every nest to avoid depleting this food source). In recent decades these practices proved unsustainable as new threats added to the naturally low survival rates of these turtles in the wild. Unregulated gold mining, dynamite/electro fishing, widespread use of illegal fishing nets, and eating of adult turtles were all factors that contributed to pushing this species to the brink of extinction.

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2015/04/150410165158.htm  Original web page at Science Daily

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* Survey of salmonella species in Staten Island Zoo’s snakes

To better understand the variety of Salmonella species harbored by captive reptiles, Staten Island Zoo has teamed up with the microbiology department at Wagner College. Eden Stark, a graduate student on the project, her advisor, Christopher Corbo, and the zoo’s curator and head veterinarian Marc Valitutto want to know how many Salmonella species live among the Staten Island Zoo rattlesnakes. The zoo has a long history of exhibiting one of the most comprehensive rattlesnake collections in the world, currently with 21 of 38 species on display. So far, Stark has surveyed 26 species of snakes. “Few other institutions have undertaken such broad scale analysis of Salmonella in snakes,” notes Valitutto. The research will be presented at the American Society for Biochemistry and Molecular Biology (ASBMB) Annual Meeting during Experimental Biology 2015

In particular, the investigators are on the lookout for pathogenic species of Salmonella, such as Salmonella arizonae. This species of Salmonella has been known to cause infections in snakes called osteomyelitis. It has a predilection for the bones, such as the vertebra. The bone may deform, and as the infection spreads, the deformed vertebrae may stop the snake from slithering. The infection may be surgically removed or treated with antibiotics if it’s localized and caught early enough. But if left untreated, the infection may eventually cause the snake to die. “If we do get a snake that is positive for arizonae, we’re concerned,” says Valitutto. “We would not want add something like that to our collection because there’s a possibility it will infect our other reptiles.” Another reason to account for the different Salmonella species is for the safety for the zookeepers. Salmonella “is strictly a pathogen for humans. It’s something that anyone who handles reptiles, even people who keep them at home as pets, has to be very cautious about in handling them or anything that is part of their enclosure,” says Corbo.

To categorize the Salmonella species, Stark isolated the bacteria from snake fecal samples. The feces were collected by seasoned zookeepers at Staten Island Zoo who know how to handle venomous snakes.  As expected, because snakes are natural hosts for Salmonella, Stark found a large number of Salmonella species in the fecal samples. She did find several species of Salmonella that are well-known as human pathogens, such as Salmonella typhimurium which can cause diarrhea, abdominal cramps, vomiting and nausea for about a week. In the few cases where Stark possibly detected the snake pathogen S. arizoniae, the news was interesting to the zoo because the snakes weren’t showing any symptoms evidence of disease. “It’s important for keepers to know that a particular species of snake is carrying a potential pathogen so they can keep an eye on it,” says Corbo.

Corbo adds that the handlers will now know that the tools they use to handle the snakes harboring S. arizonae need to be cleaned with extra care so that they don’t accidentally infect other reptiles, especially snakes. Stark is now delving further into the analysis with the polymerase chain reaction. She is testing each Salmonella species she isolates with the technique to see if the bacteria are expressing proteins known as virulence factors. This detail is important because not every potential pathogen will express virulence factors. The bacteria only become a problem if and when they turn on the expression of virulence factors and become infectious agents (for this reason, Salmonella arizonaie within snakes can even be further subdivided into more pathogenic serotypes). “You can have a species and a subspecies of Salmonella that may not carry the specific genes to cause an infection,” says Corbo. “Just because the species is there, it doesn’t mean it’s a pathogenic form of that species. That’s why it takes a lot of screening to figure out exactly what we are seeing: Is it a true pathogen with the genes necessary to be pathogenic?” Valitutto says the information from the analysis is critical for the zoo’s biosecurity protocol. As he notes, “We don’t want to send animals to other institutions that may be harboring a pathogenic strain of Salmonella.”

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2015/03/150329141003.htm  Original web page at Science Daily

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Endangered tortoises thrive on invasive plants

Introduced plants make up roughly half the diet of two subspecies of endangered tortoise, field research in the Galapagos reveals. Tortoises seem to prefer non-native to native plants and the plants may help them to stay well-nourished during the dry season. Most research on the role of introduced species of plants and animals stresses their negative ecological impacts. But are all introduced species bad actors? In one fascinating case the answer might be no. The iconic giant tortoises of the Galapagos Islands are thriving on a diet heavy on non-native plants. In fact, the tortoises seem to prefer these plants to native ones.

Introduced plants began to increase in abundance on the Galapagos Islands in the 1930s as native highland vegetation was cleared for agriculture, and the rate of introductions has been increasing ever since. The giant tortoises, for their part, seem headed in the opposite direction. Until the late Pleistocene epoch, they were found on all the continents except Antarctica. Today they survive in only two locations: the Aldabra Atoll in the Indian Ocean, and the Galapagos Archipelago in the eastern Pacific Ocean. In the Galapagos, all of the remaining subspecies are considered vulnerable or endangered. But now in a surprising turn of events, field research in the Galapagos shows that introduced plants make up roughly half the diet of two subspecies of endangered tortoise. What’s more, these plants seem to benefit the tortoises nutritionally, helping them stay fit and feisty.

The research, published in the March issue of Biotropica, was conducted by Stephen Blake, PhD, an honorary research scientist at Washington University in St. Louis and Fredy Cabrera of the Charles Darwin Foundation in the Galapagos. “Biodiversity conservation is a huge problem confronting managers on the Galapagos Islands, “Blake said. “Eradicating the more than 750 species of invasive plants is all but impossible, and even control is difficult. Fortunately, tortoise conservation seems to be compatible with the presence of some introduced species.” The study was done on the island of Santa Cruz, an extinct volcano that is home to two species of giant tortoise, but also to the largest human population in the Galapagos. Farmers have converted most of the highland moist zones to agriculture and at least 86 percent of the highlands and other moist zones are now degraded by either agriculture or invasive species.

In earlier work, Blake had fitted adult tortoises on Santa Cruz with GPS tags and discovered that they migrate seasonally between the arid lowlands, which “green up” with vegetation only in the wet season, to the meadows of the highlands, which remain lush year-round. “This struck us as pretty odd, ” he said, “since a large Galapagos tortoise can survive for a year without eating and drinking. This is why sailors would collect the tortoises to serve as a source of fresh meat aboard ship.” “Why would a 500-pound animal that can fast for a year and that carries a heavy shell haul itself up and down a volcano in search of food?,” Blake said. ” Couldn’t it just wait out the dry season until better times came with the rains?” The answer, of course, depends on the tortoise’s energy balance. But the only detailed study of tortoise foraging the scientists were aware of had been completed in 1980, “largely before the explosion of introduced and invasive species hit the Galapagos,” Blake said. Over a period of four years, the scientists followed tortoises in the field and, during 10-minute “focal observations” recorded every bite the tortoises took, the plant species and which part they ate. As an additional measure of the fruits the tortoises were eating, the scientists also counted and identified seeds (sometimes more than 1,000) in tortoise dung piles.

Counts of bites and bouts (defined as all feeding on a given species during the focal observations) showed that tortoises actually spent more time browsing on introduced species than on native ones. “We weren’t really that surprised,” Blake said. “Consider it from a tortoise’s point of view. The native guava, for example, produces small fruits containing large seeds and a small amount of relatively bitter pulp in a thick skin. The introduced guava is large and contains abundant sweet pulp in a thin, pliable skin.” The team, which included Sharon Deem, a wildlife veterinarian and epidemiologist at the St. Louis Zoo, also assessed the tortoises’ health and nutritional status, weighing them by suspending them from a spring balance and taking blood samples. All of the indicators the scientists studied suggest that introduced species in the diet have either a neutral or positive effect on the physical condition of the tortoises. Introduced species may even help tortoises to improve their condition during the dry season. Since a return to “pristine” conditions is unlikely on the Galapagos, it is heartening to learn that this may not be all bad news for the islands’ charismatic megaherbivores.

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Dwarf dragons discovered in the Andes of Peru and Ecuador

Scientists have discovered three new species of dragon-esque woodlizards in the Andes of Peru and Ecuador. The new species differ from their closest relatives in scale features, coloration and DNA. The study was published in the open access journal ZooKeys. The unusual discoveries took place in areas within the 1,542,644 km2 Tropical Andes hotspot, western South America. Finding three new species of woodlizards is a striking fact given that they are among the largest and most colorful lizards in South American forests. Woodlizards (Enyalioides) are diurnal and live in lowland tropical rainforests, such as the Chocó and western Amazon basin, as well as cloudforests on both sides of the Andes. The new species described by Torres-Carvajal et al. increases the number of species of woodlizards to 15.

Recent expeditions to several localities along the Andes of Ecuador and Peru led to the collection of several specimens of woodlizards, which the authors suspected were something new. After comparing the new specimens with those deposited in several natural history museums from many countries, the author’s suspicions became stronger. When the authors looked at DNA evidence, there were no doubts that the specimens collected recently belonged to three undescribed species of woodlizards. ‘I started working with woodlizards in 2006 as part of my postdoc at the Smithsonian Institution under the direction of Kevin de Queiroz. At that time only seven species of woodlizards had been described, and they were recognized in the literature as one of the less diverse groups of South American lizards. During the last few years we doubled the number of known species of woodlizards, showing that the diversity of these conspicuous reptiles had been underestimated. That more than half of the diversity of a group of large, dragon-looking reptiles from South America has been discovered in recent years should be heard by people in charge of conservation and funding agencies’ said Dr. Torres-Carvajal

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Are all rattlesnakes created equal? No, maybe not

But new research by a team of biologists at Florida State University has revealed that creating antivenom is a bit tricky. That’s because the type of venom a snake produces can change according to where it lives. Mark Marges, a Florida State doctoral student in Professor Darin Rokyta’s laboratory, led a research study that examined the venom of 65 eastern diamondback rattlesnakes and 49 eastern coral snakes from all over the state of Florida to determine whether snake venoms varied by geography. The venom from an eastern diamondback rattlesnake in the Florida panhandle is very different than the venom from a rattlesnake 500 miles south in the Everglades, and this has huge implications for snakebite treatment. “So if you use just southern venoms when making the antivenom, it would be ineffective against some of the more common toxins found in northern diamondback rattlesnakes,” said Florida State University doctoral student Mark Margres. In the rattlesnakes, they found significant variation linked to geography. But, in the coral snakes, they found the venom to be identical no matter where the snakes were found. “This can tell us a bit of the history and evolutionary patterns of the snakes,” said Kenny Wray, a post-doctoral research associate in Rokyta’s lab. “This suggests that the coral snakes may be recent invaders to the region and haven’t had time to evolve different venoms in different areas.” This information also will help with the development of coral snake antivenom, because scientists now know there is uniformity in coral snake venom. According to a 2012 estimate by the Center for Disease Control, 7,000 to 8,000 people in the United States are bitten by venomous snakes every year. Not only are there medical implications, this information is also important for conservation purposes. The eastern diamondback rattlesnake is being considered for federal protection under the Endangered Species Act. But, if the snakes are removed from one geographic area, they will be irrevocably deleted sfrom the ecosystem altogether. “If we lose some of these populations, we lose a whole venom type,” Rokyta said. “That really changes conservation.”

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* Biologists map crocodilian genomes

A Texas Tech University biologist led a team of more than 50 scientists who mapped the genomes of three crocodilians. By mapping these genomes, scientists may better understand the evolution of birds, which are the toothy predators’ closest living relatives, said David Ray, an associate professor of biology. The team completed genomes of a crocodile, an alligator and a true gharial to complete the genomic family portrait. “One of the major finds in our case was that crocodilian genomes change very slowly when compared to birds,” Ray said. “We compared both birds and crocodilians to turtles, which are the closest living relatives of the group that includes both birds and crocodilians. We found that they evolved slowly also. The best explanation for this is that the common ancestor of all three was a ‘slow evolver,’ which in turn suggests that rapid evolution is something that evolved independently in birds.” Research began in 2009 as an attempt to map only 1 percent of crocodilian DNA. However, shortly after starting, the price for mapping a million bases dropped from $1,000 eventually down to $1. “We had proposed to sequence about 2.4 million bases from the three crocodilians in the original proposal,” Ray said. “By the time we got the funds, it became clear that we could easily accomplish a thousand times that much and could afford to sequence an entire genome of 3 billion bases.” Ray said that when biologists look at a group of organisms, they look for what makes that group unique as well as what all members of one group of organisms share that other groups do not. The best way to do that is to examine their closest relatives. “Technically, birds’ closest relatives are the dinosaurs,” he said. “So we can only look at their fossils and this can provide only limited information on their biology when compared to examining organisms that are alive today. We get insight into differences in behavior, structures that don’t fossilize, and in our case, the makeup of the genome.” Ray said he and other scientists were surprised to see how genetically uniform the alligators that the group sequenced were. Initially, the group suspected severe hunting during most of the 20th century may be to blame. “Because alligators underwent a severe population decline, we first thought that might be what happened,” he said. “However, we see the same pattern in all three species and the likelihood that all three were subject to the same genetic bottlenecks is small. We suggested instead that change just occurs slowly in crocodilians. In other words, it wasn’t that the genetic differences were reduced because of overhunting. Rather, the amount of variation in crocodilians is low because change simply occurs slowly in these genomes.” The DNA in alligators, crocodiles and gharials is about 93 percent identical across the genome. By comparison, a human shares about 93 percent of his or her DNA with a macaque. “The difference is that humans and macaques shared a common ancestor around 23 million years ago while alligators and crocodiles shared a common ancestor in the much more distant past, around 90 million years ago,” he said. “That means that things are changing in primate genomes about four times faster than in crocodilians.” Ed Green, an assistant professor of biomolecular engineering at University of California, Santa Cruz, has worked on several mammalian genomes, including that of Neanderthals. He said he didn’t expect such slow genetic changes seen in these reptiles. “Crocodilian genomes are really interesting because they appear to have changed so little over time,” Green said. “From the perspective of someone who knows a lot about mammalian genomes, reptiles are strange in how static they are. Crocs and gators are especially static. “Like most genome projects, the assembly and annotation is only the beginning. There is some fascinating biology in Crocodylia like temperature-dependent sex determination. Male and female crocodilians are genetically identical, and we’d love to know how that works. We’re also now in the position to start looking hard at the genomes of the common ancestor of crocs and birds. Not much is known about the biology of this creature, called an archosaur. But we may hope to learn a lot about it by reconstructing its genome from the living genomes of its living descendants, the crocs and birds.”

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Turtles and dinosaurs: Scientists solve reptile mysteries with landmark study on the evolution of turtles

A team of scientists, including researchers from the California Academy of Sciences, has reconstructed a detailed “tree of life” for turtles. The specifics of how turtles are related — to one another, to other reptiles, and even to dinosaurs — have been hotly debated for decades. Next generation sequencing technologies in Academy labs have generated unprecedented amounts of genetic information for a thrilling new look at turtles’ evolutionary history. These high-tech lab methods revolutionize the way scientists explore species origins and evolutionary relationships, and provide a strong foundation for future looks into Earth’s fossil record. Research results, appearing in Molecular Phylogenetics and Evolution, describe how a new genetic sequencing technique called Ultra Conserved Elements (UCE) reveal turtles’ closest relatives across the animal kingdom. The new genetic tree uses an enormous amount of data to refute the notion that turtles are most closely related to lizards and snakes. Instead, authors place turtles in the newly named group “Archelosauria” with their closest relatives: birds, crocodiles, and dinosaurs. Scientists suspect the new group will be the largest group of vertebrates to ever receive a new scientific name. The UCE technique used in high-tech labs allowed scientists to move beyond years of speculation and place the Archelosauria group in its rightful place on the reptile tree of life. UCE has been available since 2012, yet scientists are just beginning to tap its potential for generating enormous amounts of genetic data across vertebrates. “Calling this is an exciting new era of sequencing technology is an understatement,” says Brian Simison, PhD, Director of the Academy’s Center for Comparative Genomics (CCG) that analyzed the study’s massive amount of data. The CCG is a state-of-the-art facility composed of a sequencing lab, frozen DNA collection, and computing resources that serves as the Academy’s core genetic center. Established in the summer of 2008, the CCG continues to refine Academy research — including new turtle findings — on a global, evolutionary scale. “In the space of just five years, reasonably affordable studies using DNA sequencing have advanced from using only a handful of genetic markers to more than 2,000 — an unbelievable amount of DNA,” adds Simison. “New techniques like UCE dramatically improve our ability to help resolve decades-long evolutionary mysteries, giving us a clear picture of how animals like turtles evolved on our constantly-changing planet.”

Major findings also resolve an evolutionary mystery surrounding softshell turtles — a bizarre group of scale-less turtles with snorkel-like snouts. Until now, studies linked softshell turtles with a smaller semi-aquatic group called mud turtles, despite the fact that softshells appear in the fossil record long before their mud-loving counterparts. The Academy’s study places softshells in a league of their own on the evolutionary tree, quite far removed from any turtle relatives. Their long independent history helps explain their striking looks as well as their ancient presence in the fossil record. Study coauthor James Parham, PhD — Academy Research Associate, Assistant Professor of Geological Sciences at Cal State Fullerton, and turtle expert — says cutting-edge testing techniques bring a new level of clarity to more than two decades of his turtle research. With large amounts of data backing up each evolutionary branch on the turtle tree of life, scientists are able to compare their evolution not only across species, but also across each continent’s corresponding fossil records. “I have been working on the evolutionary relationships of turtles for over 20 years using a variety of methods,” says Parham. “Fossils are essential for showing us what extinct turtles looked like, but also in letting us know when and where they lived in the past.” Parham notes that studying turtle fossils — particularly the physical features of their bones — hasn’t always painted an accurate evolutionary picture of turtle relationships across continents and through time. “The turtle tree of life based on fossil turtle anatomy didn’t match up with the timing of their appearance in the fossil record, as well as their geography,” Parham says. “But the tree of life generated at the Academy’s CCG is consistent with time and space patterns we’ve gathered from the fossil record. These new testing techniques help reconcile the information from DNA and fossils, making us confident that we’ve found the right tree.”

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* Origin of the unique ventilatory apparatus of turtles: How the tortoise’s ribs got embedded in its shell

Through the careful study of modern and early fossil tortoise, researchers now have a better understanding of how tortoises breathe and the evolutionary processes that helped shape their unique breathing apparatus and tortoise shell. The findings published in a paper, titled: Origin of the unique ventilatory apparatus of turtles, in the scientific journal, Nature Communications, on Friday, 7 November 2014, help determine when and how the unique breathing apparatus of tortoises evolved. Lead author Dr Tyler Lyson of Wits University’s Evolutionary Studies Institute, the Smithsonian Institution and the Denver Museum of Nature and Science said: “Tortoises have a bizarre body plan and one of the more puzzling aspects to this body plan is the fact that tortoises have locked their ribs up into the iconic tortoise shell. No other animal does this and the likely reason is that ribs play such an important role in breathing in most animals including mammals, birds, crocodilians, and lizards.” Instead tortoises have developed a unique abdominal muscular sling that wraps around their lungs and organs to help them breathe. When and how this mechanism evolved has been unknown. “It seemed pretty clear that the tortoise shell and breathing mechanism evolved in tandem, but which happened first? It’s a bit of the chicken or the egg causality dilemma,” Lyson said. By studying the anatomy and thin sections (also known as histology), Lyson and his colleagues have shown that the modern tortoise breathing apparatus was already in place in the earliest fossil tortoise, an animal known as Eunotosaurus africanus. This animal lived in South Africa 260 million years ago and shares many unique features with modern day tortoises, but lacked a shell. A recognisable tortoise shell does not appear for another 50 million years. Lyson said Eunotosaurus bridges the morphological gap between the early reptile body plan and the highly modified body plan of living tortoises, making it the Archaeopteryx of turtles. “Named in 1892, Eunotosaurus is one of the earliest tortoise ancestors and is known from early rocks near Beaufort West,” said Professor Bruce Rubidge, Director of the Evolutionary Studies Institute at Wits University and co-author of the paper. “There are some 50 specimen of Eunotosaurus. The rocks of the Karoo are remarkable in the diversity of fossils of early tortoises they have produced. The fact that we find Eunotosaurus at the base of the Karoo succession strongly suggest that there are more ancestral forms of tortoises still to be discovered in the Karoo,” Rubidge added. The study suggests that early in the evolution of the tortoise body plan a gradual increase in body wall rigidity produced a division of function between the ribs and abdominal respiratory muscles. As the ribs broadened and stiffened the torso, they became less effective for breathing which caused the abdominal muscles to become specialised for breathing, which in turn freed up the ribs to eventually — approximately 50 million years later — to become fully integrated into the characteristic tortoise shell. Lyson and his colleagues now plan to investigate reasons why the ribs of early tortoises starting to broaden in the first place. “Broadened ribs are the first step in the general increase in body wall rigidity of early basal tortoises, which ultimately leads to both the evolution of the tortoise shell and this unique way of breathing. We plan to study this key aspect to get a better understanding why the ribs started to broaden.”

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Giant tortoises gain a foothold on a Galapagos island

A population of endangered giant tortoises, which once dwindled to just over a dozen, has recovered on the Galapagos island of Española, a finding described as “a true story of success and hope in conservation” by the lead author of a study published Oct. 28. Some 40 years after the first captive-bred tortoises were reintroduced to the island by the Galapagos National Park Service, the endemic Española giant tortoises are reproducing and restoring some of the ecological damage caused by feral goats that were brought to the island in the late 19th century. “The global population was down to just 15 tortoises by the 1960s. Now there are some 1,000 tortoises breeding on their own. The population is secure. It’s a rare example of how biologists and managers can collaborate to recover a species from the brink of extinction, ” said James P. Gibbs, a professor of vertebrate conservation biology at the SUNY College of Environmental Science and Forestry (ESF) and lead author of the paper published in the journal PLOS ONE. Gibbs and his collaborators assessed the tortoise population using 40 years of data from tortoises marked and recaptured repeatedly for measurement and monitoring by members of the Galapagos National Park Service, Charles Darwin Foundation, and visiting scientists. But there is another side to the success story: while the tortoise population is stable, it is not likely to increase until more of the landscape recovers from the damage inflicted by the now-eradicated goats. “Population restoration is one thing but ecological restoration is going to take a lot longer,” Gibbs said. After the goats devoured all the grassy vegetation and were subsequently removed from the island, more shrubs and small trees have grown on Española. This hinders both the growth of cactus, which is a vital piece of a tortoise’s diet, and the tortoises’ movement. Chemical analysis of the soil, done by Dr. Mark Teece, an ESF chemistry professor, shows there has been a pronounced shift from grasses to woody plants on the island in the last 100 years. The shrubs and trees also inhibit the movements of the endangered waved albatross that breeds on the island. Gibbs said the plants make it difficult for the ungainly sea birds to take flight. “This is a miraculous conservation success accomplished by the Galapagos National Park Service,” said Gibbs, ” but there is yet more work to fully recover the ecosystem upon which the tortoises and other rare species depend.”

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Crocodiles are sophisticated hunters: Work as a team to hunt their prey

Recent studies have found that crocodiles and their relatives are highly intelligent animals capable of sophisticated behavior such as advanced parental care, complex communication and use of tools for hunting. New University of Tennessee, Knoxville, research published in the journal Ethology Ecology and Evolution shows just how sophisticated their hunting techniques can be. Vladimir Dinets, a research assistant professor in UT’s Department of Psychology, has found that crocodiles work as a team to hunt their prey. His research tapped into the power of social media to document such behavior. Studying predatory behavior by crocodiles and their relatives such as alligators and caimans in the wild is notoriously difficult because they are ambush hunters, have slow metabolisms and eat much less frequently than warm-blooded animals. In addition, they are mostly nocturnal and often hunt in murky, overgrown waters of remote tropical rivers and swamps. Accidental observations of their hunting behavior are often made by non-specialists and remain unpublished or appear in obscure journals. To overcome these difficulties, Dinets used Facebook and other social media sites to solicit eyewitness accounts from amateur naturalists, crocodile researchers and nonscientists working with crocodiles. He also looked through diaries of scientists and conducted more than 3,000 hours of observations himself. All that work produced just a handful of observations, some dating back to the 19th century. Still, the observations had something in common — coordination and collaboration among the crocodiles in hunting their prey. “Despite having been made independently by different people on different continents, these records showed striking similarities. This suggests that the observed phenomena are real, rather than just tall tales or misinterpretation,” said Dinets. Crocodiles and alligators were observed conducting highly organized game drives. For example, crocodiles would swim in a circle around a shoal of fish, gradually making the circle tighter until the fish were forced into a tight “bait ball.” Then the crocodiles would take turns cutting across the center of the circle, snatching the fish. Sometimes animals of different size would take up different roles. Larger alligators would drive a fish from the deeper part of a lake into the shallows, where smaller, more agile alligators would block its escape. In one case, a huge saltwater crocodile scared a pig into running off a trail and into a lagoon where two smaller crocodiles were waiting in ambush — the circumstances suggested that the three crocodiles had anticipated each other’s positions and actions without being able to see each other. “All these observations indicate that crocodilians might belong to a very select club of hunters — just 20 or so species of animals, including humans — capable of coordinating their actions in sophisticated ways and assuming different roles according to each individual’s abilities. In fact, they might be second only to humans in their hunting prowess,” said Dinets. Dinets said more observations are needed to better understand what exactly the animals are capable of. “And these observations don’t come easily,” he said.

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Pollution linked to lethal sea turtle tumors

Pollution in urban and farm runoff in Hawaii is causing tumors in endangered sea turtles, a new study finds. The study, published Tuesday in the peer-reviewed open-access journal PeerJ, shows that nitrogen in the runoff ends up in algae that the turtles eat, promoting the formation of tumors on the animals’ eyes, flippers and internal organs. Scientists at DukeUniversity, the University of Hawaii and the National Oceanic and Atmospheric Administration (NOAA) conducted the study to better understand the causes behind the tumor-forming disease Fibropapillomatosis, which is the leading known cause of death in green turtles, said Kyle Van Houtan, adjunct associate professor at Duke’s NicholasSchool of the Environment. “We’re drawing direct lines from human nutrient inputs to the reef ecosystem, and how it affects wildlife,” said Van Houtan, who is also a scientist in NOAA’s Turtle Research Program. This research builds on a study published in 2010 that found the disease was more prevalent in areas with high levels of nitrogen runoff. That study hypothesized the disease might be linked to how algae that the turtles eat store extra nitrogen, and designed this study to test that idea. “In this paper we drill down on whether excess nitrogen inputs are causing a nutrient cascade in the system that’s ending up in these tumors in green turtles,” said Van Houtan. One way that algae store excess nitrogen is in an amino acid called arginine. The researchers found unusually high levels of arginine both in the algae in highly polluted waters and in the tumors of diseased turtles. Arginine levels in algae in less polluted waters and tumor-free tissues were comparatively low. One non-native red algae species, Hypnea musciformis, had especially high levels of arginine compared to other species sampled. Hypnea is invasive and thrives in the nitrogen-rich waters caused by nutrient pollution. Since it grows more successfully than native species of algae, it can make up as much as 90 percent of the turtles’ diet. Because this algae contains so much arginine and the turtles eat so much of it, the turtles have approximately 14 times more arginine in their systems than they would if they were eating native algae species in less-polluted waters, said Van Houtan.

Even worse, the turtles, which are herbivorous, have to eat twice as much of the invasive algae species to get the same amount of calories they would gain from eating native algae. “The energy and arginine content of (the algae) may therefore act as a sort of one-two punch for promoting this disease,” the study noted. Arginine is thought to promote a virus that leads to the disease that forms the tumors. “If this disease is a car, arginine its fuel,” said Van Houtan. Without it, the virus can’t function. How the virus causes tumors is still unclear, he said. Arginine is just one of the molecules the researchers measured in the turtle tumors. They also found elevated levels of amino acids that are common in human cancer tumors, such as proline and glycine, Van Houtan said. Measuring amino acids in the turtle tumors allowed the researchers to better understand how the tumors form and function. Similar analyses of amino acids may also be useful in understanding human cancer tumors, said Van Houtan. “A hallmark of cancer tumors is that they re-program their host cells and change their metabolism. Our findings here are similar.” This research could help scientists better understand how to protect not only sea turtles but also other marine plants and animals that face similar threats from pollution. “It’s not just green turtles, but fish and coral reefs that have similar diseases in these locations,” said Van Houtan. Van Houtan said he hopes future research on this problem can inform environmental management of reef systems as a whole. “If research continues to support this hypothesis, we probably need to reconsider our current ways of managing coastal nutrients,” he said.

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Flaws emerge in RNA method to build tree of life

Scanning the genome of the painted turtle, Chrysemys picta bellii, revealed microRNAs that were reported missing in earlier studies. Tiny molecules that seemed to provide a powerful way to construct the tree of life may not have such a strong capability after all. A team of scientists has exposed flaws in a previously celebrated method that uses molecules called microRNAs to deduce evolutionary relationships between animals. As well as casting doubt over some specific results published in the past few years — for example, that turtles are more closely related to lizards than to birds and alligators — the latest findings pour cold water on what seemed like a hot approach to solving some big mysteries in evolutionary biology. As their name suggests, microRNAs are much shorter than the long RNA strands that are translated into proteins within cells. MicroRNAs instead regulate the expression of genes, an essential duty that means that the genes that code for microRNAs are expected to remain mostly unchanged from generation to generation. This presumed conservation made microRNAs seem like ideal signatures for evolutionary relationships. Subsequent observations revealed that some clearly related animals share specific microRNAs — and that these molecules are missing in animals that they are not as closely connected to. This led palaeobiologist Kevin Peterson at DartmouthCollege in Hanover, New Hampshire to pioneer a method of building evolutionary trees according the presence or absence of specific microRNAs. Over the past few years, the method has gained traction — and studies that depended on it have repeatedly attracted attention from news outlets, including Nature’s news team. One study, carried out by Peterson and his colleagues, put turtles on the same evolutionary branch as lizards, rather than close to birds, crocodiles and alligators, as previous analyses had done. The suggestion surprised researchers, including Bob  Thomson, a young evolutionary biologist at the University of Hawaii at Manoa who was also analysing turtle evolution. His own evolutionary trees, built by comparing genetic sequences, offered a different outcome. “At the time, I had the impression that microRNAs were these silver bullets to solve sexy problems, so my thought was that something was wrong with my data,” he recalls. Thomson and his colleagues re-ran the same analysis that Peterson’s team had used. This produced the same evolutionary tree — but Thomson’s team noticed something strange. The relationships among the animals suggested that a relatively large number of microRNAs had been lost over time. To Thomson, this result seemed to violate one of the main justifications for using microRNAs to build evolutionary trees in the first place: that it is almost always conserved across generations.

His team re-analysed four other microRNA studies on the trees that included flatworms, vertebrates, earthworms and some unusual parasites. Similarly, the researchers noted many more microRNA losses than expected. “The way microRNAs were being analysed probably didn’t reflect the way they evolve,” says Thomson, whose team reports the latest analysis today in Proceedings of the National Academy of Sciences. Thomson and his co-authors also applied an alternative method of analysing trees, which accommodated nuances in microRNA evolution, instead of using a method that assumes microRNA conservation through the generations. Three of the five resulting trees, including the reptile tree, more closely matched those produced by other methods. It is not clear whether Peterson’s groups did not notice the loss of the microRNAs over evolutionary time, or just didn’t report it, says Thomson. Thomson’s team also found other problems with the earlier studies, which had to do with the researchers’ raw data. Many of the microRNAs that had been presumed absent, were in fact present in the animals, but missed by the original researchers. For example, in the case of the turtle study, Peterson’s team had searched for microRNAs in RNA extracted from cells, rather than by sifting through the turtle genome — which was not available when they did the study. The discrepancy likely results from the fact that some pieces of RNA are only expressed at particular moments in an animal’s lifetime, whereas genes in the genome are steady. Peterson could not be reached by Nature for comment, but Erik Sperling, a palaeobiologist at YaleUniversity in New Haven, Connecticut, who was Peterson’s co-author on some of the microRNA analyses, agrees with Thomson’s conclusion that microRNAs cannot alone unveil species relationships. “MicroRNAs are not the panacea we perhaps originally hoped,” he says. Sperling does stand by the idea that microRNAs are generally conserved, and he says that they can be informative if better methods are used to find them, such as sifting through genomes. Plus, they should be analysed along with various genes, he says. Peterson and his colleagues recently published a new turtle tree of life that is based on microRNAs, among other information. The study refutes the earlier, controversial arrangement that put turtles on the same branch as lizards. “There are just some growing pains in the field, and this paper has pointed them out,” says Sperling. For Ken Halanych, an evolutionary biologist at AuburnUniversity in Alabama, today’s paper provides a critical analysis of a method that he has long doubted. Why did microRNAs get so much attention? “Because we are hopeful,” he says. A simple tool to decode how animals have evolved over hundreds of millions of years would certainly be nice — but it is looking unlikely that one exists.

Nature doi:10.1038/nature.2014.1562

http://www.nature.com/news/index.html  Nature

http://www.nature.com/news/flaws-emerge-in-rna-method-to-build-tree-of-life-1.15625  Original web page at Nature

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* Stem cells aid heart regeneration in salamanders

Imagine filling a hole in your heart by regrowing the tissue. While that possibility is still being explored in people, it is a reality in salamanders. A recent discovery that newt hearts can regenerate may pave the way to new therapies in people who need to have damaged tissue replaced with healthy tissue. Heart disease is the leading cause of deaths in the United States. Preventative measures like healthful diets and lifestyles help ward off heart problems, but if heart damage does occur, sophisticated treatments and surgical procedures often are necessary. Unfortunately, heart damage is typically irreversible, which is why researchers are seeking regenerative therapies that restore a damaged heart to its original capacity. We have known for hundreds of years that newts and other types of salamanders regenerate limbs. If you cut off a leg or tail, it will grow back within a few weeks. Stanley Sessions, a researcher at HartwichCollege in Oneonta, N.Y., wondered if this external phenomenon also took place internally. To find out, he surgically removed a piece of heart in more than two dozen newts. “To our surprise, if you surgically remove part of the heart, the creature will regenerate a new heart within just six weeks or so,” Sessions said. “In fact, you can remove up to half of the heart, and it will still regenerate completely!” Before the research team dove deeper into this finding, Sessions and his three undergraduate students, Grace Mele, Jessica Rodriquez and Kayla Murphy, had to determine how a salamander could even live with a partial heart. It turns out that a clot forms at the surgical site, acting much like the cork in a wine bottle, to prevent the amphibian from bleeding to death. What is the cork made of? In part, stem cells. Stem cells have unlimited potential for growth and can develop into cells with a specialized fate or function. Embryonic stem cells, for example, can give rise to all of the cells in the body and, thus, have promising potential for therapeutics.

As it turns out, stem cells play an important role in regeneration in newts. “We discovered that at least some of the stem cells for heart regeneration come from the blood, including the clot,” Sessions explained. This finding could have exciting implications for therapies in humans with heart damage. By finding the genes responsible for regeneration in the newt, researchers may be able to identify pathways that are similar in newts and people and could be used to induce regeneration in the human heart. In fact, a clinical trial performed just last year was the first to use stem-cell therapy to regenerate healthy tissue and repair a patient’s heart. Combining advances in medical and surgical technologies with the basic pathways of heart regeneration in newts could lead to better therapies for humans. Sessions posed this hopeful question: “Wouldn’t it be great if we could find a way to activate heart stem cells to bioengineer new heart tissue so that we can actually repair damaged hearts in humans?”

http://www.sciencedaily.com/  Science Daily

May 27, 2014

http://www.sciencedaily.com/releases/2014/04/140429184637.htm  Original web page at Science Daily