Thursday, March 7, 2013

Opossums, pitvipers, & venom resistance

Bushmasters are one of the snakes known to feed on venom-resistant opossums

Opossums and pitvipers are sympatric throughout most of the New World. Opossums are were not known to feed on pit vipers and pit vipers were not known to feed on opossums. In the mid 1940 Vellard discovered that three species South American Didelphis were resistant to the venom of several pitviper species. The resistance is from endogenous toxin-neutralizing serum proteins, and possibly other molecules. Vellard proposed that venom resistance evolved as an adaptation for preying on venomous snakes at the same time  he  implied the hypothesis might be proven wrong if opossums too small to eat venomous snakes, were also found to be venom resistant. Later researchers reported venom resistance in the North American opossum (Didelphis virginiana), as well as several Neotropical opossums such as, the lutrine opossum ,and the gray four-eyed opossum  To date, all of the species found to be venom resistant belong to the Didelphini clade all and are relatively large, about 500 g, and are known to feed on pit vipers. By contrast, experiments have demonstrated the brown four-eyed opossum, a small (200-300 g) species is not resistant to snake venom.

Voss (2013) reviewed the literature records of snakes feeding on opossums and found that snakes feeding on large, venom resistant opossums were sometimes based upon mis-identifications. He did find that (1) some pitvipers are preyed upon by large venom-resistant opossums; (2) many small opossums that are not known to be venom-resistant are preyed upon by pitvipers; and (3) venom-resistant opossums are preyed upon by some large pitvipers. The last situation has not been previously recognized in the literature Voss suggests two possible explanations. First, venom may be able to overcome the resistance if young individuals of venom-resistant species are bitten by large snakes. Secondly some pitvipers may have evolved unusually potent venom as a result of co-evolution with venom-resistant predatory opossums.

Voss, R. S. 2012. Opossums (Mammalia: Didelphidae) in the diets of Neotropical piutvipers (Serpentes: Crotalinae): evidence for alternative coevolutionary outcomes? Toxicon 66:1-6.

The problem with bullfrogs in Southeast Asia

Lithobates catesbeiana
A team of scientists led by the Wildlife Conservation Society (WCS) and the National University of Singapore (NUS), revealed in a new study, for the first time, the presence of the pathogenic chytrid fungus (Batrachochytrium dendrobatidis) in amphibians sampled in Singapore. And the American bullfrog may be a central player in the spread of the disease.

The study appears in the current issue of the journal EcoHealth, and is the first to consider the role that Southeast Asia's commercial trade plays in the spread of amphibian pathogens.

Demand for amphibians through local and international trade is high and fueled by use of frogs as pets, food, bait, and as a source of traditional 'medicine.' More than 40 percent of amphibian species are in decline globally due, not only to chytrid fungus, but also overharvesting, competition from invasive species, habitat loss, pollution, and climate change.

In the study, scientists collected samples from 2,389 individual animals in Lao PDR, Cambodia, Vietnam, and Singapore at 51 different sites including farms, locally supplied markets, pet stores, and from the wild.

The molecular testing of samples was led by Dr. Tracie Seimon at WCS's Molecular Diagnostic Laboratory at the Bronx Zoo. Results showed that frogs from Lao PDR and Vietnam tested negative for chytrid. In Cambodia, one frog intended for food tested positive. In addition, 74 animals in Cambodia and Vietnam were screened for ranavirus and tested negative, suggesting that these specific pathogens are not yet a conservation threat in species tested from these countries.

In Singapore, however, 13 samples tested positive for chytrid and represent the first report of chytrid in the territory. Eleven of those samples were collected from four pet stores and the remaining two were taken from amphibians in the wild.

The scientists noted that the chytrid detections were most prevalent in the American bullfrog (Lithobates aka Rana catesbeiana), a common species in the trade and one that is tolerant of chytrid infections.

"Finding chytrid in four of the seven Singaporean pet stores we sampled is cause for concern," said lead author and WCS Scientist Martin Gilbert. "Since the American bullfrog is able to tolerate this pathogen, it may act as a carrier for spreading chytrid to the region when it is imported through commercial trade."

In another alarming discovery, the scientists found that all 497 frogs sampled from 23 frog farms in Vietnam had skin lesions ranging from swelling and inflammation to ulcers and deformed or missing digits in the most severe cases. Disease examination revealed four of the animals had bacteria associated with the lesions that in two cases appeared to have spread to other organs.

While the bacteria and its role as primary or secondary pathogen could not be positively identified, the scientists noted that frog farms could serve as a source of infection for the wider environment.

The study noted that lesions among frogs raised at commercial facilities in Vietnam are of particular concern, in light of the low level of bio-security that exists. All of the farms in the study disposed of untreated wastewater directly into natural watercourses, which becomes an avenue to spread infection to other places and other species.

According to the authors, the World Organization for Animal Health (OIE) requires its 174 member countries, which include the four countries in this study, to conduct surveillance for chytrid fungus, report confirmed cases, and implement measures to control their spread.

Co-author of the study, Assistant Professor David Bickford from the Department of Biological Sciences at the NUS Faculty of Science, said, "In light of the fact that this emerging infectious disease is now known to be spread by commercial trade, it is in everyone's best interest to eliminate it from the trade in live animals before both the native amphibian populations of Southeast Asia are affected and before it completely decimates the commercial trade and people are unable to make a living. This is not just about the frogs."

The paper concludes, "There is an urgent need to conduct wider surveys of wild amphibians in Southeast Asia to determine the extent and severity of chytrid fungus and other infectious diseases among a range of species, and whether and how these change over time. Studies should focus on differentiating Batrachochytrium dendrobatidis strains that may be endemic to the region from exotic strains that may be introduced through routes including international trade."

Liolaemus & Climate Change

Liolaemus tenuis in Maipo Canyon, Chile (near San Alfonso). Photo credit: Kaldari

The following pres release from the University of  Lincoln describes research on the genus Liolaemus, a clade of lizards restricted to southern South America.  It holds about 230 species, nine of which were described during 2012. Many of these lizards have adapted to high elevations and the long cold season associated with them. In the process, they have been able to switch their mode of reproduction from live-bearing to egg-laying many times. The forthcoming paper has been published early on-line and a link to the abstract is at the bottom of the page.

Climate change could lead to dozens of lizard species becoming extinct within the next 50 years, according to new research published this week.

Globally it has been observed that lizards with viviparous reproduction (retention of embryos within the mother’s body) are being threatened by changing weather patterns. A new study suggests that the evolution of this mode of reproduction, which is thought to be a key successful adaptation, could, in fact, be the species’ downfall under global warming.

Dr Daniel Pincheira-Donoso, from the School of Life Sciences at the University of Lincoln (UK), is the lead author of the paper detailing these amazing predictions, published in the scientific journal Global Ecology and Biogeography.

Researchers, including academics from the University of Exeter, investigated the hypothesis that historical invasions of cold climates by Liolaemus lizards – one of the most diverse groups of vertebrates on earth – have only been possible due to their evolution to viviparity (live birth) from oviparity (laying eggs). Remarkably, once these species evolve viviparity, the process is mostly irreversible and they remain restricted to colder climates.

By analysing this evolutionary transition in the lizards’ reproductive modes and projecting the future impact of climate change, the scientists discovered that increasing temperatures in the species’ historically cold habitats would result in their areas of distribution being significantly reduced. As a consequence, if global warming continues at the same rate, viviparous lizards are facing extinction in the next few decades.

Dr Daniel Pincheira-Donoso is one of the few people in the world who works on the ecology and evolution of these lizard species.

He said: “Lizards’ reproduction is largely linked to climatic temperatures and viviparous species are usually found in cold environments. When reptiles initially moved to colder areas they needed to evolve emergency measures to succeed in these harsh places, and we believe viviparity is one of these key measures. However, this transition is mostly one-directional and unlikely to be reversed. Rapid changes in the environment’s temperature would demand rapid re-adaptations to secure the species’ survival. Through the research we found that over the next 50 years nearly half of the area where these species occur may disappear, causing multiple extinction due to climate change.”

Overall the conclusion is that although viviparity allowed lizards in the past to invade and adapt to live in cold environments, and was therefore a key trait for evolutionary success, it will now ultimately lead to multiple events of extinction.

Dr Pincheira-Donoso said: “These lizards are one of the most diverse groups of animals, and are able to adapt to remarkably diverse conditions. Unfortunately, a reduction in cold environments will reduce their areas of existence, which means that their successful evolutionary history may turn into a double-edged sword of adaptation. Their extinction would be an atrocious loss to biodiversity.”

Dr Dave Hodgson, from the University of Exeter, said: “Climate change must not be underestimated as a threat to modern patterns of biodiversity. Our work shows that lizard species which birth live young instead of laying eggs are restricted to cold climates in South America: high in the Andes or towards the South Pole. As the climate warms, we predict that these special lizard species will be forced to move upwards and towards the pole, with an increased risk of extinction.”

Pincheira-Donoso, D., Tregenza, T., Witt, M.J. & Hodgson, D.J. The evolution of viviparity opens opportunities for a lizard radiation but drives it into a climatic cul-de-sac. Global Ecology and Biogeography, 2013

Wednesday, February 27, 2013

Clotting Factors from a Saw-scaled Viper

Saw Scaled Viper In Mangaon, MH, India.
Photo credit: Shantanu Kuveskar

The powerful venom of the saw-scaled viper Echis carinatus contains both anticoagulants and coagulants finds a study published in the launch edition of BioMed Central's open access journal Journal of Venomous Animals and Toxins including Tropical Diseases. These may be a source of potent drugs to treat human disease.

The saw-scaled viper family Echis, responsible for most snake attacks on humans, are recognizable by the 'sizzling' noise they make, produced by rubbing together special serrated scales, when threatened. Echis venom causes coagulopathy, which can result in symptoms ranging from lack of blood clotting, hemorrhage, renal failure and stroke.

Researchers from the Razi Vaccine and Serum Research Institute, Iran led by Hossein Zolfagharian noted that treating plasma with venom from Echis carinatus actually causes it to coagulate. Splitting the venom by ion exchange chromatography showed that then venom contained both coagulants and anticoagulants. The clotting factors alone were toxic to mice.

The diametric effects of snake venom on blood are of interest because of medical applications, and although snakes can be considered as dangerous to humans -- they may yet save lives.

Hossein Salmanizadeh, Mahdi Babaie and Hossein Zolfagharian. In vivo evaluation of homeostatic effects of Echis carinatus snake venom in Iran. Journal of Venomous Animals and Toxins including Tropical Diseases, 2013, 19:3 DOI: 10.1186/1678-9199-19-3

Monday, February 25, 2013

Siamese crocodiles reintroduced in Lao PDR

The following is a WCS Press Release.
Members of the Village Crocodile Conservation
Group prepare to release three of the nineteen
Siamese crocodiles.
Photo Credit: Alex McWilliam/WCS.

THAN SOUM, LAO PDR (February 21, 2012) — The Wildlife Conservation Society announced today the successful release of 19 critically endangered baby Siamese crocodiles into a local wetland in Lao PDR, where they will be repatriated into the wild.

The 19-month-old hatchlings, approximately 70 cm (27 inches) in length, are part of a head-starting program where crocodiles are hatched at the Lao Zoo for eventual release into their native habitat.

Conservationists estimate that less than 250 Siamese crocodiles remain in the wild due to overhunting and habitat loss.

The release took place in the village of Than Soum in the Xe Champhone wetland complex in Savanakhet Province near where the eggs of the 19 crocodiles were found during wildlife surveys in 2011.

The hatchlings were transported from the Lao Zoo to a ‘soft release’ pen and will remain for several months to acclimate with the local area. Members of the Village Crocodile Conservation Group will guard the pen and provide supplementary feeding of the hatchlings to ensure their survival. Once the rainy season begins, the water level in the wetland will rise and allow the crocodiles to swim away, where they will be monitored periodically by conservationists.

A public ceremony will take place on March 6th in Than Soum where local community members will celebrate this collaborative effort with WCS, Government of Lao PDR, Ministry of Natural Resources and Environment, Minmetals Resources Limited, and the Lao Zoo.

WCS Lao PDR Program designed and implemented the release as part of the Community-based Crocodile Recovery and Livelihood Improvement Project. The goal of the program is the recovery of the local Siamese crocodile population and restoration of associated wetlands, linked by socio-economic incentives that improve local livelihoods.

“We are extremely pleased with the success of this collaborative program and believe it is an important step in contributing to the conservation of the species by involving local communities in long term wetland management,” said Alex McWilliam a conservation biologist with WCS’s Lao PDR Program. “The head starting component of this integrated WCS program represents a significant contribution to the conservation of this magnificent animal in the wild.”

Rick Watsford, General Manager, MMG Lane Xang Minerals Limited Sepon, said: “MMG is proud to support the work of the Government of Lao PDR and the WCS in relation to this program. This support demonstrates our company’s commitment contributing positively to the communities in which we operate.”

Joe Walston, WCS Executive Director for Asia Programs, said: “Successful conservation is about partnerships – whether it’s at the global level with climate change and wildlife trade or the local level with tigers and crocs – the collective support of local communities, governments, and the private sector in Laos makes stories like this so encouraging.”

Classified as Critically Endangered by the International Union for the Conservation of Nature, the Siamese crocodile grows up to 10 feet in length. The species has been eliminated from much of its former range through Southeast Asia and parts of Indonesia by overhunting and habitat degradation and loss.

In 2014, the head-starting component of the program will be taken on by local communities in the Xe Champhone wetland complex. WCS has already conducted training for this transition and implemented a trial program of rearing young crocodiles at Than Soum village.

Sunday, February 24, 2013

Cultivating snakes in China

The following is from the Global Times. Visit the original story to see the interesting photographs.

The first batch of snakes arrives in the village, 
ready for raising in the new year. Photo: Yang Hui/GT.
Nestled away in Zhejiang Province, the village of Zisiqiao has nurtured a reputation as being one of China's "best snake villages." Producing about 3 million snakes every year, 90 percent of its 170 families depend on snake-raising for income, even rearing venomous snakes such as cobras and fer-de-lances.

Internationally, about 70 percent of breeding snakes come from China, and 30 percent of China's snakes are bred in this one village, according to Yang Hongchang, 60, known as "the snake king." Villagers don't raise snakes all year around but from when they hatch in spring and sell them before winter comes.

Almost every villager has been bitten by snakes numerous times. Yet local children are not afraid of snakes at all. "People in the city keep dogs or cats, while our children raise snakes as pets. They put snakes in the bathtub to bathe together in summer," a villager told the Global Times.

"People in snake villages raise snakes as other people raise chickens or cattle, and they do it as a profession," Jiang Zhigang, a researcher with the Institute of Zoology at the Chinese Academy of Science, told the Global Times.

Besides, raising wild animals in the proper way is encouraged by the Chinese government, as it can provide medical products and also help boost protection, awareness and research about wild animals, Jiang said.

For many people, snakes are a repulsive species, but to Yang, every part of the snake is a treasure as their skin, gall and venom all have medical uses. Yang has been raising snakes for over 20 years and has witnessed the process of Zisiqiao village lifting itself out of poverty thanks to their scaly friends.

In the 1980s, Yang was as poor as other villagers. He was seriously ill and needed to take traditional Chinese medicine containing snake parts or organs, but couldn't afford the medicine fees. He thought of catching snakes himself since they were found in abundance around the village.

His health condition improved and he gradually became a master snake-catcher. He sold the snakes and made more money than in his previous fishing trade. This inspired other villagers to follow Yang's career change.

However, this wave of popularity meant that the number of snakes began to decrease until Yang hit on the idea of raising them.

In 1985, Yang spent all his savings on building a snake farm, the first one in Zisiqiao. After years of learning and practice, he managed to raise 50,000 snakes, and earned over 100,000 yuan. Again, villagers followed his lead.

Now, Yang has three enterprises, focused on the breeding of vipers, production of snake meat and processing of health remedies. Their combined yearly sales totaled 20 million yuan last year, according to Zhejiang local media.

Last year, the village established a snake museum, the first of its kind in China. They now plan to build a reptile rehabilitation center, and he is confident that Zisiqiao will become more prosperous, as the Year of the Snake has just begun.

Saturday, February 23, 2013

Results of the Python Challenge

The following is from the National Parks Traveler. It is the most reasonable summary of the Python Challenge results that I have found.  The results are expected and telling. More than 1600 people sign up to look for invasive pythons in the Florida Everglades, after a month they find 68 snakes (= 0.0425 snakes/person). The conclusion - pythons are adept at hiding. They are in places people cannot access. JCM
Florida Fish and Wildlife Conservation Commission
 biologist Kevin Enge with Burmese python. 
FWC photo by David Cook

The results of Python Challenge 2013, a multi-agency effort that offered cash prizes to promote the removal of non-native Burmese pythons from the greater Everglades area in southern Florida, are now in the books.

Although the end result was bad news for exotic pythons, winners included the successful hunters, scientists and parks—and three lucky snakes.

Participants who bagged both the largest number of pythons as well as the largest individual snake netted tidy cash awards, and scientists gained valuable information to aid in the on-going battle against the unwelcome invaders. The exotic (non-native) pythons pose a serious threat to other wildlife in Florida, and that includes areas such as Everglades National Park and Big Cypress National Preserve.

Nearly 1,600 people from 38 states, the District of Columbia and Canada registered for the competition, which allowed hunting for the snakes on public lands in four state-designated wildlife management areas (WMAs) in the greater Everglades area: Everglades and Francis S. Taylor, Holey Land, Rotenberger and Big Cypress. The Big Cypress WMA includes much of the land within Big Cypress National Preserve.

Organizers Pleased With Results

Results of the competition were announced recently by The Florida Fish and Wildlife Conservation Commission (FWC), and although the number of snakes captured—68—may seem low given the number of hunters in the field, organizers were pleased with the outcome.

The major goal was to "heighten public awareness about this invasive species," and the event "also proved to be an unprecedented opportunity to gather important data about Burmese python populations and their impact on the Everglades ecosystem."

When dropping off a harvested Burmese python, contest participants were required to complete a data sheet providing information such as the snake’s size, GPS location and habitat where it was found. Data is still being analyzed, so it's not yet known if any of the reptiles came from National Park Service property at Big Cypress National Preserve.

“Thanks to the determination of Python Challenge competitors, we are able to gather invaluable information that will help refine and focus combined efforts to control pythons in the Everglades,” FWC Executive Director Nick Wiley said. “The enthusiastic support from the public, elected officials, conservation organizations, government agencies and researchers gives hope that we can make progress on this difficult conservation challenge by working together.”

Good News for Three Snakes?

For three of the captured snakes there was a bit of a surprising outcome: They were released back to the wild, but this wasn't a concession to PETA or other snake-lovers. Their temporary freedom offers a chance to bag even more of their kind.

Prior to their release, each of the seemingly lucky reptiles were fitted with a pair of radio transmitters to allow researchers to track their movements. The resulting data should provide valuable information about the snake's activities and preferred locations and thus lead to the eventual removal of a larger number of pythons, whose natural camouflage makes them very difficult to locate in the wild. For an example of the challenge of spotting one of the snakes in the dense Florida grass, take a look at this photo.

The timing of the release was a strategic decision, since it's breeding season and it's hoped the radio-tagged snakes will be looking for love in all the right places. The tagged snakes are expected to seek out fertile females, who can then be located and removed before they add yet another crop of young snakes to the Florida wetlands. The tracking devices will also allow the trio of tagged reptiles be recaptured later this spring.

Winning Hunters Announced

As to the contest itself, there were two separate Python Challenge™ competitions: the General Competition for the public and the Python Permit Holders Competition for people who have permits from the Florida Fish and Wildlife Commission (FWC) and other agencies to regularly harvest these snakes.

The $1,500 Grand Prize for harvesting the most Burmese pythons went to Brian Barrows, who harvested six pythons in the General Competition, and Ruben Ramirez, who harvested 18 pythons in the Python Permit Holders Competition.

The $1,000 First Place Prize for harvesting the longest Burmese python went to Paul Shannon, who harvested a 14-foot, 3-inch-long python in the General Competition, and Blake Russ, who harvested an 11-foot, 1-inch-long python in the Python Permit Holders Competition.

Python Challenge 2013 was organized by the Florida Fish and Wildlife Conservation Commission (FWC) and involved a wide-ranging list of partners, including the University of Florida, South Florida Water Management District, The Nature Conservancy, The Future of Hunting in Florida, the Wildlife Foundation of Florida, Zoo Miami, Big Cypress National Preserve, and Everglades National Park.

Hunt Results Also Good News for Most Park Visitors

The rather small number of snakes captured during the month-long event despite the best efforts of hundreds of highly motivated hunters also holds a bit of good news for many park visitors, most of whom are not interested in encountering snakes of any size.

An Everglades National Park spokesperson commented that the extensive media coverage of the python situation in the Everglades has created a misconception for many visitors about the likelihood that they'll encounter one of the large snakes in the park. As the outcome of the recent contest has shown, it's very unlikely most visitors will ever see one of the reptiles.

Wildlife officials remind the public that everyone can help in the fight against invasive species by reporting any sightings of Burmese pythons and other exotic animals at this link. On-the-spot reports, described as "If you've got a live animal in front of you in Florida right now," should be reported by calling 1-888-IVE-GOT-1

Thursday, February 21, 2013

Roads & snakes in Saskatchewan

An eastern yellow-bellied racer (Coluber constrictor flaviventris) in Texas
Photo Credit: David Sledge.

Roads contribute significantly to mortality of snakes and can greatly increase the probability of local extinction. In North America populations of some snake species have declined or been extirpated due to road mortality. The abundance of larger snakes was reduced by more than 50% within 450 m of  a state highway (high traffic volume) and forest service system and county roads (lower traffic volume) in the Angelina National Forest in eastern Texas. Fortney and colleagues (2013) investigated road mortality as a threat to Canadian snake populations in the Grasslands National Park of Canada (GNP) area of southwestern Saskatchewan. The area has a unique snake community within Canada with six snake species: Plains Gartersnake (Thamnophis radix), Wandering Gartersnake (Thamnophis elegans vagrans), Bullsnake (Pituophis catenifer sayi), Prairie Rattlesnake (Crotalus viridis), Eastern Yellow-bellied Racer (Coluber constrictor flaviventris), and Western Hog-nosed Snake (Heterodon nasicus).

Forty-five systematic surveys of roads in the Grasslands National Park area in 2009 yielded 36 dead and 18 live snakes. Multivariate modelling revealed that proximity to hibernacula was positively correlated with presence of snakes on roads. Paved roads had a disproportionately higher numbers of snake mortality, suggesting that traffic patterns are a bigger risk factor than road use per se. Some radio-tracked Eastern Yellow-bellied Racers (2 of 17; 12%) and Bullsnakes (Pituophis catenifer sayi) (4 of 5; 80%) captured at emergence from hibernacula had road areas in their home ranges. The individuals equipped with radio-transmitters used roads and immediately adjacent areas significantly more than expected, based on their availability, suggesting possible selection for roads. Strategies to reduce road mortality of snakes should focus on key stretches of roads, such as those near winter hibernacula or riparian zones. The placement of paved roads in sensitive areas like those in and around Grasslands National Park should be carefully considered to minimize snake mortality.

Fortney, Ashley N., Ray G. Poulin, Jessica A. Martino, Dennilyn L. Parker, and Christopher M. Somers. 2012. Proximity to hibernacula and road type influence potential road mortality of snakes in southwestern Saskatchewan. Canadian Field-Naturalist 126(3): 194–203.

Wednesday, February 20, 2013

A very large aquatic Palaeophiine snake from Morroco's Eocene

Fossil snakes of the Palaeophiinae snakes are relatively poorly known, but they inhabited the oceans, lakes, rivers and possibly the land from the Maastrichtian to the Late Eocene. This subfamily includes the two genera Palaeophis and Pterosphenus. Palaeophiinae includes a wide range of species of various sizes. The largest species known to date is considered to be Palaeophis colossaeus estimated to be about 9 m long, whereas the smallest species P. casei  is estimates at about 1–1.3 m long. This subfamily includes various species illustrating three ecological grades. The ‘primitive’ Palaeophis grade comprises species with vertebrae only slightly modified for an aquatic life, whereas the ‘advanced’ Palaeophis includes species with vertebrae clearly modified for an aquatic life The third grade is comprised only of Pterosphenus, whose vertebrae are highly modified for an aquatic life.

Palaeophis maghrebianus described by Arambourg in 1952 is one of the better documented species, but it has not been revised since its original description. It is only known from the Ypresian Phosphates of Morocco. And, it is the only squamate discovered in the Ypresian of Moroccan Phosphates to date. This large snake is considered aquatic based on its vertebral morphology. However, it belongs to the ‘primitive’ Palaeophis grade.

The discovery of new isolated vertebrae and three articulated vertebral segments, which correspond to the longest vertebral segments known for a palaeophiine, enabled Houssaye and colleagues (2013) to obtain new anatomical data about this species which is reported in a forthcoming article the journal Paleontology.

Houssaye et al. (2013) examined the  microanatomical and histological features of some vertebrae to obtain new information about the biology and palaeoecology of this snake.

Within palaeophiids, P. maghrebianus appears to be relatively poorly adapted to an aquatic life with the vertebrae only weakly compressed laterally. These vertebrae appear peculiarly compact, as a result of a combined inhibition of primary bone remodelling and of additional deposits of secondary bone during remodelling. A high vertebral compactness has also been observed in the living marine snakes of the genus  Hydrophis and the freshwater homalopsid snake Enhydris bocourti. These data are thus consistent with an aquatic mode of life for this taxon. Palaeophis was a near-shore and estuarine dweller that lived in shallow marine, brackish and possibly freshwater environments.   Eocene mangrove environments were inhabited by  the ‘advanced’ palaeophiid Pterosphenus. But, Pterosphenus was found also in an open marine environment. Palaeophis, even those of the ‘advanced’ group, were likely not pelagic animals. Shallow aquatic environments including mangroves were especially favorable to Palaeophiidae.

This new specimen has vertebrae much larger than the previously known for this species. Vertebrae reach 3.3 cm in length; as compared to a maximal length of 1.9 cm in a 5.9-m long specimen of Python reticulatus. Palaeophis maghrebianus was probably much longer than the biggest extant snakes. Along with P. colossaeus, it becomes one of the two longest palaeophiids, assuming that the number of vertebrae was similar in these two species.

A dense vascular network was observed in P. maghrebianus vertebrae. Vascularization is generally absent or consists of a few simple vascular canals radially oriented in extant squamates. Vascularization is observed in only the largest species of extant squamates and the degree of vascularization in P. maghrebianus is much higher than in the common anaconda, Eunectes murinus or the reticulated python, Python reticulatus. This important vascular network indicates that P. maghrebianus was growing much faster and thus had a much higher metabolic rate than the largest extant snakes.

Arambourg. C. 1952. Les vertébrés fossiles des gisments de phosphates (Maroc- Algérie- Tunisie). Service Geologique du Maroc, Notes et Mémoires 92:1-372.

HOUSSAYE, A., RAGE, J.-C., BARDET, N., VINCENT, P., AMAGHZAZ, M. and MESLOUH, S. (2013), New highlights about the enigmatic marine snake Palaeophis maghrebianus (Palaeophiidae; Palaeophiinae) from the Ypresian (Lower Eocene) Phosphates of Morocco. Palaeontology. doi: 10.1111/pala.12008.

Friday, February 15, 2013

A New Aquatic Snake From Brazil's Mato Grosso

Helicops apiaka sp. nov. (UFMT-R 8180), live specimen from
aranaíta municipality, Mato Grosso State, Brazil, with a detail of
ventral coloration (lower right corner).

The aquatic snake genus Helicops Wagler, 1830, is widely distributed in South America  and of closely related to Hydrops and Pseudoeryx. Currently, 15 species of Helicops are recognized with five species (H. danieli, H. pastazae, H. petersi, H. scalaris, and H. yacu) endemic to northwestern Amazonia in Ecuador, Colombia, Peru, and Venezuela. Ten species are known to occur in Brazil, with four of them restricted to southeastern and southern regions (H. carinicaudus, H. gomesi, H. infrataeniatus, and H. modestus). The remaining six species occur in the Brazilian Amazon (H. angulatus, H. hagmanni, H. leopardinus, H. polylepis, H. tapajonicus, and H.trivittatus).

Kawashita-Ribeiro and colleagues (2013) recently collected specimens that resemble the  widespread H. angulatus from the Brazilian state of Mato Grosso, but which differed  in color pattern and scalation. They named it Helicops apiaka, and it is from the type locality of Paranaíta, in the state of Mato Grosso, Brazil. It is distinguished from all other Helicops by its dorsal scales in 21/21/19 rows in males and 23/21/19 rows in females; as well as other scale characters, and its blotched ventral surface.

Kawashita-Ribeiro, R.A, Ávila, R. W., Morais, D.H.. 2013. A New Snake of the Genus Helicops Wagler, 1830 (Dipsadidae, Xenodontinae) from Brazil. Herpetologica 69(1):80-90.

Saturday, February 9, 2013

The Monstersauria & Venom Delivery

Gila monster teeth. JCM

Lizards and snakes are diverse in both feeding and defense strategies and some used modified teeth to deliver venom to prey and  predators. The oldest known squamate with grooves in its teeth, similar to those found in the modern heloderms (gila monster and beaded lizards), is the monstersaura Estesia mongoliensis
 In living lizards, only members in the genus Heloderma have grooved marginal teeth used for venom delivery. Heloderms are low in diversity and geographically restricted to southwestern United States , Mexico and Guatemala. In contrast, the fossil monstersaurs related to Heloderma, are found in North America, Europe and Asia. 

The Monstersauria clade is a group of mostly large, carnivorous anguimorph lizards, and includes the extant Heloderma and stem taxa. Monstersaurs differ from other anguimorph lizards in the possession of venom grooves in their marginal teeth. In living heloderms the venom grooves extend from the root of a tooth to its tip, and are used for venom delivery. While the venom grooves in fossil monstersaurs are shallower. 
The fossil record of monstersaurs in North America dates back to the Late Cretaceous. In the Cenozoic, fossil monstersaurs are commonly known from the Oligocene and Miocene. Fragmentary materials are known from Nevada as well as  the Pleistocene of southern California and the Mio-Pliocene of Tennessee. Heloderma texana is known from the Miocene of Texas and is represented by articulated skulls. The grooved marginal teeth and thickened osteoderms of H. texana closely resemble those in extant heloderms. Lowesaurus matthewi is known from the Oligocene to the Miocene of Colorado and Nebraska , represented by isolated skull elements and trunk vertebrae. There is also an un-named taxon from the Miocene of Florida that has grooved teeth resembling those of extant Heloderma. Mesozoic records of monstersaurs in North America include Palaeosaniwa canadensis,  Paraderma bogerti, and Primaderma nessovi. Parasaniwa wyomingensis may also be as a basal monstersaur becase it seems to have dental “venom grooves” 

Eurheloderma gallicum is the only monstersaurian taxon known from Europe. It is known to have grooved marginal teeth, but detailed description of these grooves is lacking. In Asia, fossil monstersaurs have also been discovered at several localities in the Upper Cretaceous of the Mongolian Gobi Desert.  
Estesia mongoliensis is the largest monstersaur (skull length 150 mm) and it is known from several skulls and postcranial materials. Estesia mongoliensis has grooved teeth but no osteoderms on the skull. Gobiderma pulchrum is known from articulated skulls and skeletons, has mound-shaped osteoderms that are fused to the skull, but lacks grooved teeth. It has been assigned to various anguimorph lineages by different authors but recent work, based on several new specimens, found strong support for this taxon as a basal monstersaur. 

Estesia mongoliensis was first described in 1992 as the sister group to Lanthanotus and varanidae but it was later suggested to be  more closely related to Heloderma, with new braincase characters.  Several subsequent studies generally found Estesia mongoliensis as a monstersaur  although other authors reported Estesia mongoliensis grouped with varanoid. 

A new study  by Yi and Norell (2013) reports on new Estesia mongoliensis specimens from the Upper Cretaceous of Mongolia, including a three-dimensionally preserved skull. The authors phylogenetically analyze 86 anguimorph taxa coded with 435 morphological characters and four genes and they confirm the placement of Estesia mongoliensis in a monophyletic Monstersauria.

 Yi and Norell found that Estesia mongoliensis has two shallow grooves in the rostral and caudal carinae of its dentary teeth, demonstrating a primary venom-delivery apparatus. The phylogeny supports a single origination of venom grooves in the Monstersauria, and suggests  that grooved teeth are currently the only reliable venom-delivery apparatus to be recognized in fossil lizards.

Yi, H-Y and M. Norell. 2013. New materials of Estesia mongoliensis (Squamata, Anguimorpha) and the evolution of venom grooves in lizards. American Museum novitates, no. 3767, 31 pp.

Thursday, February 7, 2013

The unusual herp diversity of Luzon's Sierra Madre Mountain Range

Hologerrhum philippinum

A recent study of the amphibians and reptiles of Sierra Madre Mountain Range, northeastern Luzon, reveals a preliminary enumeration of more than 100 species that contribute to the unique biodiversity of the region. At present, the Luzon region's herpetological range stands at more than 150 species. Out of these, a total of 49 amphibian species have been documented, 44 of which are native and a remarkable 32 endemic. In the world of reptiles, Luzon can boast with 106 native species, 76 of which are unique to this region.

The catalogue published in the open access journal Zookeys features a fascinating range of reptiles and amphibians, such as the beautifully coloured colubrid snake Hologerrhum philippinum, which is one of the four endemic snake genera from the region and can be recognized by the vibrant-yellow skin decoration. Another species that provokes amazement is the bizarre soft-shell turtle Pelochelys cantorii. The variety described in this study includes fascinating frogs, crocodiles, snakes, lizards and many more, offering a menagerie of shapes and colours all documented in stunning photography.

With such a great array of biodiversity, the northern Philippines has been the focus of of large numbers of new species discoveries and re-discoveries of new species in recent decades, establishing it as a major regional biodiversity hotspot. The herpetological diversity of the island may grow to as many as 90-100 (70-80% endemic) amphibian species and as many as 150-160 reptiles with the contributions of ongoing biodiversity studies in the near future. It will be a major challenge to monitor these communities through time in order to assess their responses to land use changes, climate change, resource extraction, introduced species, emerging infectious disease, and habitat degradation.

With the initial baseline information provided in the survey, tremendous opportunities exist for future studies in taxonomy, biogeography, ecology and conservation of northern Luzon's amphibians and reptiles. Conservation of Luzon's vertebrate biodiversity remains an on-going effort, challenged by rapid development,logging, mining and conversion of natural habitats into agricultural lands to provide food for a burgeoning human population.

Brown RM, Siler CD, Oliveros CH, Welton LJ, Rock A, Swab J, Van Weerd M, van Beijnen J, Jose E, Rodriguez D, Jose E, Diesmos AC (2013) The amphibians and reptiles of Luzon Island, Philippines, VIII: the herpetofauna of Cagayan and Isabela Provinces, northern Sierra Madre Mountain Range. ZooKeys 266: 1-120. doi: 10.3897/zookeys.266.3982

Update - The Python Challenge 2013

The following article is a modified version of an on-line article at

The 800 participants in the Python Challenge have been actively searching for invasive pythons for almost a month, and the even will be coming to a close on 16 February. The Florida Fish and Wildlife Conservation Commission considered the goals of the event to raise public awareness and increase the agency’s knowledge base regarding this invasive species and how to better understand and address impacts on the Everglades ecosystem, including native wildlife.

For competitors, the challenge is to harvest the well-camouflaged Burmese python, with the chance of winning prizes of up to $1,500. Registrants have come from more than 30 other states.

To date 50 snakes have been turned in to the University of Florida for data collection.

Frank Mazzotti is leading a University of Florida research team that is examining Burmese python carcasses brought in through a statewide hunt. He's had dead snakes in and out of his lab for weeks as Florida tries to rid itself of a few very large pests.

Scientists say the pythons are squeezing Florida ecosystems the way they squeeze life out of their prey. The Florida Fish and Wildlife Conservation Commission created the first-ever Python Challenge this year to lower their numbers and to raise public awareness about the invasive species.

Beginning Jan. 12, participants have been able to hunt pythons in four wildlife management areas: the Everglades and Frances S. Taylor, Holey Land, Rotenberger and Big Cypress.

Fifty pythons had been "harvested" as of Tuesday, according to the Python Challenge website, which means 50 fewer snakes wreaking havoc on Florida's ecosystems and especially the Everglades. Participants can turn snakes in until Sunday.

It's hard to know how many pythons wind through the Everglades, said Robin Bijlani, the media coordinator for UF's Fort Lauderdale Research and Education Center.

"There's no significant estimate anywhere, really," she said. Some counts guess 150,000, others 1,500. Mazzotti generally avoids giving estimates, Bijlani said, for exactly that reason.

Mazzotti and his fellow researchers at the center examine each snake turned in for the contest, and Bijlani said critics have been quick to point out that the contest might not make much of a dent in python numbers.

But the challenge is providing more than just a few less pounds of muscle and scale in Florida's swamps. All carcasses entered in the challenge are dropped off for examination, which Mazzotti said can provide clues about their size, eating habits and possible contamination.

It's too early to spot trends in the findings, Mazzotti said, but he's glad the challenge is raising awareness of Florida's problem with pythons and invasive species in general. When he heard about the challenge, he offered UF as science support.

The Python Challenge has received public support statewide, and U.S. Sen. Bill Nelson drew attention when he joined the hunt and dropped a carcass off for examination.

The most successful hunters will get rewards, but data from the UF researchers might prove the most valuable result.

Jack Hayes, the dean for research at UF's Institute of Food and Agricultural Sciences, said the center is one of 13 sites IFAS operates around the state.

They function as extensions of the university that allow hands-on regional research and put researchers and graduate students from different disciplines into one lab.

About a dozen people work in the python necropsy lab, but only six or so actually perform necropsies, Bijlani said. Two people can usually perform a necropsy on a large python in about two hours, start to finish.

Ten-and-a-half foot snakes have been common, she said, although that's larger than average. Sometimes three people have to help slice the skin, remove fat pads and take internal samples.

After measurements and samples have been taken, the snake is hollowed out for hunters to reclaim the skin and meat.

Mazzotti said his team has been making good time handling the Python Challenge in addition to regular surveys and studies. The snakes don't even sit in the lab long enough to start smelling. It's busy but manageable.

It feels like the most time-consuming part of the challenge, he said, has been talking to the news media Frank Mazzotti keeps his countertop tidy -- sharp tools as needed, a roll of paper towels, a glass dish or two. It's free of clutter, free of smells -- and the kitchen sink shines.

Wednesday, February 6, 2013

Asian Wolf Snakes - A Molecular Revision

Lycodon aulicus, Bannerghatta, India. Photo credit: Saleem Hameed

Asian wolf snakes of the genus Lycodon are one of many poorly understood radiations of advanced snakes in the superfamily Colubroidea. Only three of species (of about 37)  have been previously  represented in higher-level phylogenetic analyses, and nothing is known of the relationships among the species in this unique, moderately diverse, group. The genus occurs widely from central to Southeast Asia, and contains both widespread forms and some that are endemic to small islands. One-third of the diversity is found in the Philippine archipelago. Both morphological similarity and highly variable diagnostic characters have contributed to confusion over species-level diversity. Additionally, the placement of the genus in the subfamily Colubrinae remains uncertain, although previous studies have supported a close relationship with the genus Dinodon (contains another eight species). In a forthcoming paper in Zoological Scripta Siler et al. provide the first estimate of phylogenetic relationships within the genus Lycodon using a new multi-locus data set. They provide statistical tests of monophyly based on biogeographic, morphological and taxonomic hypotheses. With few exceptions, we are able to reject many of these hypotheses, indicating a need for taxonomic revisions and a reconsideration of the group's biogeography. Mapping of color patterns on their preferred phylogenetic tree suggests that banded and blotched types have evolved on multiple occasions in the history of the genus, whereas the solid-color (and possibly speckled) morphotype color patterns evolved only once. Their results suggest that the colubrid genus Dinodon is nested within Lycodon—a clear finding that necessitates the placement of Dinodon within Lycodon.

Siler, C. D., Oliveros, C. H., Santanen, A., Brown, R. M. (2013). Multilocus phylogeny reveals unexpected diversification patterns in Asian wolf snakes (genus Lycodon). Zoologica Scripta,doi:10.1111/zsc.12007

An new pterosaur from Transylvanian

A new kind of pterosaur, a flying reptile from the time of the dinosaurs, has been identified by scientists from the Transylvanian Museum Society in Romania, the University of Southampton in the UK and the Museau Nacional in Rio de Janiero, Brazil.

Map showing the global distribution of faunas containing small-medium and giant-sized azhdarchids, evidence for niche partioning. Image rendering courtesy of Mark Witton; map imagery by kind permission of Ron Blakey, Colorado Plateau Geosystems, Inc.Add caption
The fossilised bones come from the Late Cretaceous rocks of Sebeş-Glod in the Transylvanian Basin, Romania, which are approximately 68 million years old. The Transylvanian Basin is world-famous for its many Late Cretaceous fossils, including dinosaurs of many kinds, as well as fossilised mammals, turtles, lizards and ancient relatives of crocodiles.

A paper on the new species, named Eurazhdarcho langendorfensis has been published in the international science journal PLoS One. Dr Darren Naish, from the University of Southampton’s Vertebrate Palaeontology Research Group, who helped identify the new species, says:

“Eurazhdarcho belong to a group of pterosaurs called the azhdarchids. These were long-necked, long-beaked pterosaurs whose wings were strongly adapted for a soaring lifestyle. Several features of their wing and hind limb bones show that they could fold their wings up and walk on all fours when needed.

“With a three-metre wingspan, Eurazhdarcho would have been large, but not gigantic. This is true of many of the animals so far discovered in Romania; they were often unusually small compared to their relatives elsewhere.”

The discovery is the most complete example of an azhdarchid found in Europe so far and its discovery supports a long-argued theory about the behaviour of these types of creatures.

Dr Gareth Dyke, Senior Lecturer in Vertebrate Palaeontology, based at the National Oceanography Centre Southampton says:

“Experts have argued for years over the lifestyle and behaviour of azhdarchids. It has been suggested that they grabbed prey from the water while in flight, that they patrolled wetlands and hunted in a heron or stork-like fashion, or that they were like gigantic sandpipers, hunting by pushing their long bills into mud.

“One of the newest ideas is that azhdarchids walked through forests, plains and other places in search of small animal prey. Eurazhdarcho supports this view of azhdarchids, since these fossils come from an inland, continental environment where there were forests and plains as well as large, meandering rivers and swampy regions.”

Fossils from the region show that there were several places where both giant azhdarchids and small azhdarchids lived side by side. Eurazhdarcho’s discovery indicates that there were many different animals hunting different prey in the region at the same time, demonstrating a much more complicated picture of the Late Cretaceous world than first thought.

Mátyás Vremir, Alexander W. A. Kellner, Darren Naish, Gareth J. Dyke. A New Azhdarchid Pterosaur from the Late Cretaceous of the Transylvanian Basin, Romania: Implications for Azhdarchid Diversity and Distribution. PLoS ONE, 2013; 8 (1): e54268 DOI: 10.1371/journal.pone.0054268