Saturday, July 26, 2014

A tiny, new microhylid from Brazil's Atlantic Forest

This image shows the male holotype of the new species
 Chiasmocleis quilombola. Phoyo Credit: João F. R. Tonini
The Atlantic Forest is a hotspot of biodiversity and one of the most species richness biome of anurans (frogs, tree-frogs, and toads) in the world. However, current levels of diversity might be still underestimated. In the past few years has been an increase in the description of new endemic species of this biome along with the advance of molecular techniques and availability of samples for DNA analysis.

Using a more extensive number of samples for molecular and morphological analysis, researchers from the University of Richmond and The George Washington University described a tiny new species of narrow-mouthed frog from the Microhylidae family in the open access journal ZooKeys.

Chiasmocleis quilombola occurs in the Atlantic Forest of the Espírito Santo State, southeastern Brazil. Despite its modest size, adult males reach only about 14 mm (adult females 17 mm), the new species bears a heroic name inspired by the quilombos communities typical of the Espírito Santo State in Brazil, where the frogs were collected.

The specific epithet "quilombola" used for the species' name refers to the people who inhabited these communities -- slaves who dared to escape during colonial times and find a refuge in the depths of the Atlantic Forest.

Quilombos were used as a refuge for escaped slaves during colonial Portuguese rule in Brazil between 1530 and 1815. Even today in the north of Espírito Santo State quilombola communities still remain and maintain alive their traditions, such as quilombola food and craftwork.

"We were puzzled by the morphological variation of those frogs, which is little, but after the first results of the molecular phylogeny was clear there was higher genetic disparity among them," say João Tonini, Ph. D. student at The George Washington University. Chiasmocleis quilombola occupy coastal areas north of Espírito Santo State, a region that is under strong human pressure, therefore the species may face imminent threat of habitat loss.

Citation
João Filipe Tonini, Maurício Forlani, Rafael de Sá. A new species of Chiasmocleis (Microhylidae, Gastrophryninae) from the Atlantic Forest of Espírito Santo State, Brazil. ZooKeys, 2014; 428: 109 DOI:10.3897/zookeys.428.7352


Friday, July 25, 2014

A feeding aggregation of Boa constrictors

Boa constrictor (individual 1) predating Rufous-bellied Thrush 
on a trumpet tree. The black arrow indicates the bird's wing 
and the white arrow points out a conspecific (individual 2) on a 
parallel branch. Photo Gilson da Rocha Santos. 
Sit-and-wait predators remain motionless for long periods of time, waiting for prey to come within range of their reach. The choice of locations for the ambush can determine the success of the predator, and some snakes species (e.g., Boa constrictor;  Crotalus horridusEchis coloratus;  Epicrates inornatusGloydius shedaoensis) increase their chances of prey capture by selecting microhabitats that are frequently visited by the prey.

In a recent paper by Rocha-Santos et al. (2014) the authors reports on the Boa constrictor using fruiting Trumpet trees (Cecropia spp.). Cecropia are fast growing pioneers, associated mainly to secondary forests, found throughout the Neotropical area, from the south of Mexico to the north of Argentina. They can reach up to 22 meters and have long fruiting periods (up to 12 months) and they attract several omnivore and frugivorous species, including passerines, galliforms, parrots, marmosets, bats and coatis.

Boas are robust snakes that can reach up to 300 cm of total length. They are habitat generalists present throughout the Neotropics area, present in rainforests, savannas and wetlands. They are sit-and-wait strategists capable of detecting prey, probably using visual, thermal and chemical stimuli and they feed efficiently in terrestrial and arboreal environments. Published records suggest they prey on most major groups of vertebrates.

The authors observed the predatory behavior of boas during fieldwork in a Cerrado remnant of 50 ha belonging to Private Natural Heritage Reserve, Universidade Federal de Mato Grosso do Sul, Campo Grande, Brazil.  The reserve is located in an urban area, which is surrounded by boulevards and buildings of the UFMS campus. Vegetation is composed by trees reaching 15-18 m tall, smaller trees, shrubs, and herbaceous plants.

They observed the capture of a Rufous-bellied Thrush (Turdus rufiventris) by a boa on the branch of a 8 m trumpet tree. The Rufous-bellied Thrush landed on the branch, about 50 cm, from a snake probably in search of fruit, and was instantly captured and constricted. The snake touched the bird with its labial scales, inspecting it, and started ingesting by the bird’s head. Ingestion lasted about 14min, and the snake returned to its initial position (partially aligned on the branch). At the same time, we spotted two other snakes positioned on parallel branches in same tree.  The snakes were separated by 0.5 to 2 m of space.

The following morning the three snakes were in the same positions, probably the same individuals sighted in the previous day. And the authors observe another Rufous-bellied Thrush landing on a branch near the second individual. However, the bird managed to dodge the attack, escaping capture. Three minutes later the third snake captured a Great Kiskadee (Pitangus sulphuratus). No interactions among the snakes were observed.

Citation

Rocha-Santos, G. D., Barbier, E., & Bordignon, M. O. (2014). Sweet trap: Boa constrictor (Serpentes: Boidae) preying on passerines on Cecropia pachystachya (Urticales: Cecropiaceae) in fruiting periodBiota Neotropica, 14(2): 1-4.

Wednesday, July 23, 2014

Divergence in Shaw's Vivipiparous Sea Snake

Hydrophis curtus
Species are not evenly distributed on earth and regions that are exceptionally rich in endemic species suffering habitat loss are commonly referred to as biodiversity hotspots. The Indo-Australian archipelago has unusual high levels of biodiversity threatened by increasingly human generated activities. The region supports the one of world's highest diversity of marine fish, invertebrates and reptiles. Many of the marine organisms show congruent phylogeographic patterns, supporting the view that the region's complex geo-climatic history has played an important role in generating its exceptional biodiversity.

Ukuwela et al., (in press, 2014) examined the population genetic structure of the viviparous sea snake, Hydrophis curtus, to assess how past and present barriers to gene flow in the Indo-Australian archipelago have contributed to genetic and species diversity in a fully marine reptile.

Mitochondrial and anonymous nuclear sequences and ten microsatellite loci were used to identify patterns of historical genetic structure and population expansion, reconstruct dated genealogies and assess levels of recent gene flow. These markers revealed strong concordant geographic structure within H. curtus with a prominent genetic break between populations broadly distributed in the Indian Ocean and the West Pacific. These populations were estimated to have diverged in the late Pliocene or early Pleistocene, and microsatellite admixture analyses suggested limited recent gene flow between them despite the current lack of barriers to dispersal, indicating possible cryptic species.

Subsequent divergence in the mid–late Pleistocene was detected within the West Pacific clade among the populations in the Phuket-Thailand region, South-East Asia and Australia, and two of these populations also showed genetic signals of recent range expansions. The results show that climatic fluctuations during the Plio-Pleistocene generated high levels of cryptic genetic diversity in H. curtus, and add to similar findings for diverse other marine groups in the archipelago.


Citation

Ukuwela, K. D. B., de Silva, A., Mumpuni, Fry, B. G. & Sanders, K. L. (in press, 2014). Multilocus phylogeography of the sea snake Hydrophis curtus reveals historical vicariance and cryptic lineage diversity. — Zoologica Scripta, 

Alaskan wood frogs spend most of their life frozen

An Alaska wood frog creates a hibernacula from duff and leaf litter in a 
spruce forest on the University of Alaska Fairbanks campus in preparation 
for the long winter freeze. Photo Credit: Photographer: Uwe Anders
Freezing and thawing might not be good for the average steak, but it seems to help wood frogs each fall as they prepare to survive Alaska's winter cold.

"Alaska wood frogs spend more time freezing and thawing outside than a steak does in your freezer and the frog comes back to life in the spring in better shape than the steak," said Don Larson, University of Alaska Fairbanks graduate student and lead author on a recent paper demonstrating that freeze tolerance in Alaska wood frogs is more extreme than previously thought.

Although wood frogs are well-studied freeze-tolerant amphibians, Larson's research is believed to be the first to examine the frogs under natural conditions.

In subarctic Interior Alaska, wood frogs overwinter in the ground covered by duff and leaf litter, creating a hibernacula, where temperatures can remain below freezing for more than six months with minimum temperatures of minus four (-20 Celsius).

Tracking wood frogs to their natural hibernacula, and using a fenced hibernacula in the Biological Reserve north of the UAF campus, Larson and co-author Brian Barnes, director of the UAF Institute of Arctic Biology and an expert in cold-climate physiology, wanted to know how cold and how long Alaska's wood frogs could survive in their natural habitat.

"Imagine what happens when you suck on a freeze pop," said Larson. "After you've sucked out all the sweet stuff, you're left with just ice. That's what happens to cells when they freeze. As ice formation pulls the water out of cells, the cells desiccate or dry out and eventually die."

Frogs prevent this freeze-pop effect by packing their cells with glucose (a kind of sugar) that reduces drying and stabilizes cells, a process scientists call cryoprotection.

"Concentrating sugar inside the cell helps balance the concentration of salts outside the cell that occurs as ice forms," said Barnes. "Less water leaves the cell than if sugar was not present and sugar and other cryoprotectants are thought to "hold" water inside the cell."

The curious thing Larson discovered is that when wood frogs are outside in their natural environment they accumulate much higher concentrations of glucose in their tissues than do frogs frozen in the lab.

Glucose concentrations in the outside frogs were 13-fold higher in muscle tissue, 10-fold higher in heart tissue and 3.3-fold higher in liver tissue compared to lab-frozen frogs, as described in their paper published in the Journal of Experimental Biology.

This extra protection enabled frogs to survive colder temperatures for a longer time than scientists previously thought, but Larson and Barnes wondered how they accumulated so much glucose?
Larson thinks the process that creates freezer burn on a frozen steak gives frogs the ability to survive being frozen at minimum temperatures below zero (-18 Celsius) for up to 218 days with 100 percent survival.

Frogs collected from sites in the Eastern U.S. and Canada have previously been shown to only survive being frozen for a few weeks and to no lower than about -19⁰ (-7.2 Celsius).

"In the field in early Autumn it's freezing during the night, thawing slightly during the day, and these repeated freezing episodes stimulate the frogs to release more and more glucose," Larson said. "It's not warm enough for long enough for the frog to reclaim much of that glucose and over time it accumulates giving the frog more protection against cell damage."

Lab-frozen frogs are held at a constant temperature and without the freeze-thaw cycles Larson observed in the wild and so the frogs made glucose only when they initially froze and that was that.

"Whether the extremes in freezing tolerance in Alaska frogs as compared to more southern populations are due to patterns of temperature change during freezing or are due to genetic differences, and thereby represent evolutionary change, awaits further study," said Barnes.

The feats of freezing frogs are more than just a curiosity and may one day have application in the science of human organ transplantation.

"If science can figure out how to freeze human organs without damage it would allow more time to reach people in need of organs," said Larson.

Citation
D. J. Larson, L. Middle, H. Vu, W. Zhang, A. S. Serianni, J. Duman, B. M. Barnes.Wood frog adaptations to overwintering in Alaska: new limits to freezing tolerance. Journal of Experimental Biology, 2014; 217 (12): 2193 DOI:10.1242/jeb.101931



Tuesday, July 22, 2014

The earliest reptile?

The skull of Gephyrostegus bohemicus.
University of Lincoln
Paleontologists from the Natural History Museum and academics from Lincoln, Cambridge and Solvakia have recreated the cranial structure of a 308-million-year-old lizard-like vertebrate that could be the earliest example of a reptile and explain the origin of all vertebrates that belong to reptiles, birds and mammals.

Dr Marcello Ruta, from the School of Life Sciences, University of Lincoln, UK, was one of the authors of the paper which is published in the Journal of Vertebrate Paleontology and produced a series of intricate hand-drawn recreations of the cranial structure of Gephyrostegus.

Paleontologists have provided a new cranial reconstruction of a long-extinct limbed vertebrate (tetrapod) from previously unrecognized specimens found in coal deposits from the Czech Republic.

The team of academics reviewed the cranial structural features of the Late Carboniferous
Gephyrostegus bohemicus -- a small animal of generally lizard-like build that lived 308 million years ago.

This early tetrapod could be the earliest example of a reptile and explain the origin of amniotes, all vertebrates that belong to reptiles, birds and mammals.

Experts from, Comenius University in Bratislava (Slovakia), University Museum of Zoology in Cambridge, The Natural History Museum in London, and the University of Lincoln, UK, have been able to study additional specimens unavailable in previous works.

Their aim was to provide an analysis of early tetrapod relationships incorporating their new observations of Gephyrostegus. Their analysis used skeletal traits across a sample of early tetrapod groups to identify the likely affinities of Gephyrostegus.

Dr Marcello Ruta, from the School of Life Sciences, University of Lincoln, UK, was one of the authors and produced a series of intricate hand-drawn recreations of the cranial structure of Gephyrostegus.

He explained: "Gephyrostegus has always been an elusive beast. Several researchers have long considered the possibility that the superficially reptile-like features of this animal might tell us something about amniote ancestry. But Gephyrostegus also shows some much generalized skeletal features that make the issue of its origin even more problematic. We conducted a new study that brings together data from a large number of early tetrapods. The study shows that Gephyrostegus is closely related to another group of Eurasiatic and North American tetrapods called seymouriamorphs, also involved in debates about amniote ancestry. 

We found some interesting new cranial features in Gephyrostegus that helped us establish this link.
"Staring at specimens for a long time down a microscope and trying to make sense of their anatomy may be frustrating and tiring at times, but always immensely rewarding."
  
Citations

Jozef Klembara, Jennifer A. Clack, Andrew R. Milner, Marcello Ruta. Cranial anatomy, ontogeny, and relationships of the Late Carboniferous tetrapod Gephyrostegus bohemicusJaekel, 1902. Journal of Vertebrate Paleontology, 2014; 34 (4): 774 DOI: 10.1080/02724634.2014.837055

Wednesday, July 16, 2014

Ophidiomyces ophiodiicola in the eastern massasauga


University of Illinois at Urbana-Champaign
Researchers have developed a faster and more accurate way to test for infection with Ophidiomyces ophiodiicola, a fungus that is killing snakes in the Midwest and eastern United States. The test also allows scientists to monitor the progression of the infection in living snakes.

The researchers reported on the test at the 2014 Mycological Society of America Annual Meeting.
“We need people to know that they don’t have to anesthetize an animal to collect a biopsy sample or, worse yet, euthanize snakes in order to test for the infection,” said University of Illinois comparative biosciences department professor Matthew Allender, an expert in snake fungal disease. “Now we can identify the infections earlier, we can intervene earlier and we can potentially increase our success of treatment or therapy.”

The new test uses quantitative polymerase chain reaction (qPCR), which amplifies fungal DNA to identify the species present and measure the extent of infection.

Researchers first took notice of Ophidiomyces in snakes in the mid-2000s. Today the fungus threatens the last remaining eastern massasauga rattlesnake population in Illinois and has been found to infect timber rattlesnakes, mud snakes, rat snakes, garter snakes, milk snakes, water snakes and racers in several states, Allender said.

“I’ve tested snakes from Illinois, Tennessee and Michigan, and we’ve tested samples from snakes in New Jersey, Georgia and Virginia,” Allender said. Snakes in Connecticut, Massachusetts, Minnesota, New Hampshire, New York, Ohio and Wisconsin have also tested positive for the fungus.

Ophidiomyces consumes keratin, a key ingredient in snake scales. It can cause scabs, nodules, abnormal molting, ulcers and other disfiguring changes to snake skin. Mortality is 100 percent in Illinois massasauga rattlesnakes found with outward signs of infection, Allender said. There are only 100 to 150 massasaugas left in Illinois, he said, and about 15 percent of those are infected with the disease.

Allender also is an affiliate of the Illinois Natural History Survey, part of the Prairie Research Institute at the U. of I. He and his INHS colleague, mycologist Andrew Miller, liken this emerging fungal disease in snakes to white-nose syndrome, another fungal disease that has killed millions of North American bats. Miller and graduate student Daniel Raudabaugh recently published an analysis of Pseudogymnoascus destructans, the fungus implicated in white-nosed syndrome, and are repeating the analysis on Ophidiomyces.

“The fungus killing these snakes is remarkably similar in its basic biology to the fungus that has killed over 6 million bats,” Miller said. “It occurs in the soil, seems to grow on a wide variety of substances, and possesses many of the same enzymes that make the bat fungus so deadly.”

Other colleagues at the INHS, herpetologists Michael Dreslik and Chris Phillips, have been studying eastern massasauga rattlesnakes in the wild for 15 years, and are working closely with Allender to characterize both biological and health factors that lead to infection. The new qPCR test is integral to this mission, Allender said. It also will help the team develop new therapies to treat infections in snakes.

“This work is truly collaborative across disciplines, allowing the team to make advances in studying this disease that haven’t been accomplished anywhere else,” Allender said.

“Our qPCR is more than 1,000 times more sensitive than conventional PCR,” Allender said. “We can know how many [fungal spores] are in a swab and then we can start to treat the snake and we can watch to see if that number is going down.”

The researchers also are hoping to find new disinfectants that will kill the fungus so that researchers who are studying snakes in the wild will not spread it to new locales on their equipment or shoes.
“Some of our preliminary studies show that the common disinfectants that we use are not effective,” Allender said. “This fungus overcomes it.”


Source: University of Illinois at Urbana-Champaign

Divergence within Boa constrictor imperator

Boa constrictor imperator, Belize. JCM
The Boa constrictor species complex has the widest distribution of any boid, with a latitudinal range from Mexico (30° N) to Argentina (35° S), and inhabiting a variety of environments Some geographically delimited populations have been recognized as subspecies, which exhibit extensive variation in morphological and ecological traits. Despite their popularity in the pet trade and relatively high abundance, no comprehensively detailed phylogeographical studies exist for this species. The only published work, based mostly on boas from captive breeders, describes two clades (based upon cytochrome b): one from Mexico and Central America, and the other encompassing localities from South America. The Central American clade coincides with the recognized subspecies Boa constrictor imperator Daudin, 1803.

Suárez‐Atilano and colleagues sampled throughout the range of B. c. imperator in Neotropical Mexico and continental Central America and used nuclear and mitochondrial molecular markers to infer the biogeographical processes that determine population structure in a coalescent framework, an approach that allows patterns at different spatial and temporal scales to be examined. The workers characterize the boa’s genetic diversity and phylogeographical structure to test: (1) whether it demonstrates key spatial patterns observed in other vertebrates in this region, such as a Pacific–Atlantic divergence; (2) whether times of divergence of lineages were related to historical and dispersal events occurring in Mexico and Central America; and (3) whether biogeographical boundaries in the region, like the Mexican Transition Zone delimit the current genetic groups.

Cytochrome b results revealed two main reciprocally monophyletic lineages, one along the Mexican Pacific coast and another along the Gulf of Mexico, Yucatan Peninsula and Central America, diverging about 5.2 million years ago. Both lineages are subdivided into haplogroups and show steady historical growth and a more recent population expansion. High genetic diversity was observed for both cytochrome b and microsatellites
. The authors demonstrate a deep phylogeographical structure with two reciprocally monophyletic lineages and five genetic clusters in Mexico and Central America. And, the results suggest that several geographical barriers (including the Trans-Mexican Volcanic Belt and the Motagua–Polochic–Jocoan faults) and ecological features generated this genetic structure, and suggest that the two lineages may be considered distinct species.

Citation

Suárez‐Atilano, Marco, Frank Burbrink, and Ella Vázquez‐Domínguez. "Phylogeographical structure within Boa constrictor imperator across the lowlands and mountains of Central America and Mexico." Journal of Biogeography (2014).

Moving Massasaugas

Relocating animals is a commonly used conservation technique. In the case of venomous snakes, relocation is often prompted by the potential for negative human-snake interactions. However, other reasons to relocate snakes include the re-establishment of extirpated populations, the establishment of new populations of imperiled species in more suitable locations, and augmentation of imperiled populations.
            The varied outcomes of studies done on snake relocation suggest the technique remains an experimental rather than an established conservation method for snakes. The diverse outcomes reflect the fact that relocation is not a single technique, but a collection of techniques that vary according to the extent of displacement and the source of relocated individuals (wild or captive-born). When snakes are moved short distances, such as might occur when a “nuisance” snake is moved away from the point of conflict, homing behavior can result in the snakes simply returning to the area from which they were moved. Short-distance translocation (i.e., relocation of wild animals within their home range) may also cause snakes to alter their behavior in ways that increase mortality in some cases, but not in others.
            In a new study, Harvey et al. (2014) conducted two types of relocation (repatriation and short-distance translocation) using Eastern Massasaugas (Sistrurus c. catenatus) in Ontario. For the repatriation experiment, 27 snakes were captive-born, raised for four years, and released into a nature reserve previously known to host massasaugas. Other than being relatively sedentary, snakes behaved normally upon release in that they engaged in reproductive behavior. Survival was relatively high at 70% until hibernation (19 weeks). However, none of the snakes that did hibernate (n = 19) survived into the following active season.
            In a preliminary assessment of the effects of short-distance translocation, snakes that the researchers moved 200 m from capture locations (n = 4) did not return, nor did they exhibit abnormal movement or basking behavior relative to non-translocated controls (n = 7). The different outcomes of our two relocations could indicate that the success of relocation depends on the extent of displacement and the source of relocated individuals, although corroborating evidence is needed before these results can be used to support management strategies.

Citation

Harvey, DS, Lentini AM, Cedar K, PJ Weatherhead. 2014. Moving massasasauguas: insight into rattlesnake relocation using Sistrurus c. catenatus. HerpetologicalConservation and Biology 9:67-75.

World Snake Day


Sunday, July 13, 2014

A new arrangement for the blind snake superfamily Typhlopoidea

The blindsnake superfamily Typhlopoidea is a diverse and widespread part of the global snake fauna. The superfamily Typhlopoidea now contains three families: Gerrhopilidae, Typhlopidae, and Xenotyphlopidae. Gerrhopilidae inhabits South and Southeast Asia and the East Indies. Xenotyphlopidae occurs only in northeastern Madagascar. But, Typhlopidae is widespread, containing at least 257 species. Typhlopids have major radiations in the New World tropics, Africa, Madagascar, South Asia, Southeast Asia, and Australia and new species are commonly reported from all of these areas. The true diversity of the group is probably much higher, as evidenced by a recent molecular study of Australian Ramphotyphlops, which showed that the actual number of species is 200–340% greater than currently recognized.

The discovery and description of new species is limited by their fossorial life styles (making them difficult to encounter), and relatively conserved morphology (making them difficult to diagnose and delimit). As a result, there has been little in-depth phylogenetic analysis or systematic investigation of the group, usually restricted primarily to single geographic areas and relatively few characters. Throughout most of their recent history, all blindsnakes were included in the genus Typhlops. In the mid-20th century, solid coiled hemipenes and paired retrocloacal sacs were discovered in the Australasian radiation, leading these species to be separated into Ramphotyphlops. The name Typhlina was also applied to this group, but was found to be in the synonymy of both Ramphotyphlops and Leptotyphlops, and was thus later suppressed by the International Commission on Zoological Nomenclature on appeal. Until very recently, most species were placed in Typhlops and Ramphotyphlops. Other genera were erected or resurrected and species moved between them on the basis of morphological characters, but rarely, if ever, from phylogenetic analysis of either morphological or molecular data. These include the African radiation, and two morphologically divergent groups from Oceania. The genus Cathetorhinus was resurrected for the morphologically divergent Typhlops melanocephalus, which was previously considered incertae sedis. The genus Grypotyphlops was resurrected for Rh. acutus, the only Indian member of a group otherwise found solely in Africa. Multiple species groups were identified within these larger genera (particularly Typhlops), based on shared morphological features such as the number of lateral and transverse scale rows, supralabial imbrication patterns, hemipenial morphology, and lung architecture. The differences between these groups suggested that current taxonomic arrangements did not describe monophyletic genera. This suspicion was confirmed by recent molecular phylogenetic analyses, which revealed that numerous taxonomic problems existed within Typhlopidae, and that previous nomenclature did not reflect monophyletic groups revealed in the available phylogenies. The morphological distinction between Ramphotyphlops and Typhlops was not corroborated by molecular evidence, and species from these and other genera interdigitated with each other in molecular phylogenies.

In a new paper Pyron et al. (2014) provide a systematic revision based on molecular phylogenetic analyses and some morphology and present a preliminary solution to the non-monophyly of many previously recognized genera. They also found additional clarification is needed regarding the recognition of some species and genera. They rectify these problems in a new paper with a new molecular phylogenetic analysis that includes 95 of the 275 currently recognized, extant typhlopoids, incorporating both nuclear and mitochondrial loci. They supplement this with data on the external, visceral, and hemipenial morphology of nearly all species to generate a revised classification for Typhlopoidea. Based on morphological data, the re-assign Cathetorhinus from Typhlopidae to Gerrhopilidae. Xenotyphlopidae maintains its current contents (Xenotyphlops). In Typhlopidae, one monotypic genus is synonymized with its larger sister-group as it cannot be unambiguously diagnosed morphologically (Sundatyphlops with Anilios), and two genera are synonymized with Typhlops (Antillotyphlops and Cubatyphlops), as they are not reciprocally monophyletic. The genus Asiatyphylops is renamed Argyrophis, the senior synonym for the group. They also erect one new genus (Lemuriatyphlops) for a phylogenetically distinct species-group in Asiatyphlopinae. Fourteen of eighteen recognized typhlopid genera are maintained in four subfamilies: Afrotyphlopinae (Afrotyphlops, Grypotyphlops [re-assigned from Asiatyphlopinae], Letheobia, and Rhinotyphlops), Asiatyphlopinae (Acutotyphlops, Anilios, Cyclotyphlops, Indotyphlops, Malayotyphlops, Ramphotyphlops, and Xerotyphlops), Madatyphlopinae (Madatyphlops), and Typhlopinae (Amerotyphlops and Typhlops), some with altered contents. Diagnoses based on morphology are provided for all 19 typhlopoid genera, accounting for all 275 species. This taxonomy provides a robust platform for future revisions and description of new species.

Citation
Pyron, R. A., Wallach, V., & Press, M. (2014). Systematics of the blindsnakes (Serpentes: Scolecophidia: Typhlopoidea) based on molecular and morphological evidence. Zootaxa3829(1), 001-081.

Thursday, July 10, 2014

Two new montane rattlesnakes from Mexico


Members of the Mexican dusky rattlesnake species group (Crotalus triseriatus Group) are widely distributed across the highlands of Mexico and the southwestern USA. Currently the group contains five species. The nominate species, C. triseriatus, contains the subspecies C. t. triseriatus and C. t. armstrongi, which inhabit mixed pine-oak forests across the Trans-Mexican Volcanic Belt. Crotalus pusillus ranges across the highlands of the Sierra de Coalcomán and the western portion of the Trans-Mexican Volcanic Belt. Crotalus aquilus, previously considered a subspecies of C. triseriatus, occurs north of the Trans-Mexican Volcanic Belt along the Central Mexican Plateau in mixed pine-oak and rocky mesquite grasslands. Crotalus lepidus is the widest ranging species in the group. It contains four subspecies distributed across a variety of habitats in northern Mexico and southwestern USA. Crotalus l. lepidus occurs in rocky regions of the Chihuahuan Desert and adjacent uplands, C. l. klauberi inhabits the Sierra Madre Occidental and sky islands of the southwestern USA and northern Mexico, C. l. morulus occurs in the northern Sierra Madre Oriental, and C. l. maculosus occupies the Pacific slopes of the southern Sierra Madre Occidental. Crotalus ravus was recently added to the C. triseriatus group and it includes three subspecies, C. r. ravus, C. r. brunneus, and C. r. exiguus, found along the eastern slopes of the Trans-Mexican Volcanic Belt and Sierra Madre del Sur. Species composition of the C. triseriatus group has changed several times over the past 70 years. The most recent molecular studies of the group found strong support for a monophyletic assemblage that includes C. triseriatus, C. pusillus, C. aquilus, C. lepidus, and C. ravus. One of these studies also found evidence that C. triseriatus and C. lepidus are paraphyletic and that at least one cryptic species was present within the C. triseriatus group. Although this study extensively sampled the geographic range of the C. triseriatus group, analyses reconstructed matrilineal relationships only because of a reliance on mitochondrial DNA.

Despite seven decades of systematic study, no study has tested species limits in the C. triseriatus group. Species within the group were recognized and classified long ago based on morphology alone. Recent research has focused on reconstructing phylogenies or on using phylogenies to address evolutionary and biogeographic questions.

In a new study Bryson and colleagues (2014) use data from seven nuclear loci to test competing models of species delimitation in the C. triseriatus group. They tested different models of species delimitation using the recently developed Bayes factor delimitation (BFD) method, and compare models that reflect historical taxonomy against models that reflect phylogeographic structure and contain cryptic species. They also examined museum specimens for morphological congruence to cryptic species along the Trans-Mexican Volcanic Belt hypothesized in a previous study.

They find strong support for a nine-species model and genetic and morphological evidence for recognizing two new species within the group, which are formally describe. The results suggest that the current taxonomy of the C. triseriatus species group does not reflect evolutionary history.

Crotalus tlaloci sp. nova is described based on 11 specimens. It was named after the Aztec god of rain and inhabits open areas in cloud forest and humid oak-pine forest along the lower slopes of the Trans-Mexican Volcanic Belt. Although one record in the Sierra de Taxco (“Arroyo las Damas”) is at 1850 m  most records are between 2000–2400 m asl. This species is known from the states of Guerrero, Estado de México, Michoacán, and Morelos, and may range into western Puebla. The Tlaloci rattlesnake uses broad-leaf oak forest with dense undergrowth, a habitat that is distinctly different than the drier pine-oak forest inhabited by C. triseriatus. The distribution of C. tlaloci overlaps the ranges of two alligator lizards, Barisia herrerae and B. rudicollis. Interestingly, both of these alligator lizards occur in similar humid forest habitat at elevations of 2000–2500 m asl, and appear ecologically isolated from B. imbricata, which inhabits the surrounding drier pine-oak forest. Specimens of C. tlaloci are generally found in rocky open forest breaks and edges of cloud or humid oak-pine forest.

Crotalus campbelli sp. Nova was named in honor of Johnathan Campbell and is based upon six specimens. It occurs in rocky, open breaks within montane forest along the far western regions of the Trans-Mexican Volcanic Belt. Much of this forest is covered with remnant patches of cloud forest. This species is known from western Jalisco and the Sierra de Manantlán in southern Jalisco/northwestern Colima. A narrow low-elevation valley appears to separate the range of C. campbelli from C. armstrongi to the east.

Citation

Bryson, R. W., C. W. Linkem, M. E. Dorcas, A. Lathrop, J. M. Jones, J. Alvarado-Díaz, C. I. Grünwald, and R. W. Murphy. 2014. Multilocus species delimitation in the Crotalus triseriatus species group (Serpentes: Viperidae: Crotalinae), with the description of two new species. Zootaxa 3826: 475-496.

Frog adaptations to an invasive crayfish

The common frog is one of the amphibians with the highest distribution in the Iberian Peninsula. It reproduces preferably in permanent areas of water where it comes into contact with the red swamp crayfish, which preys on its larvae. Research carried out by the Spaniard Germán Orizaola from the University of Uppsala (Sweden) confirms that the larvae of these frogs have developed a defensive response to the invasive species. They also have deeper tails and larger bodies if they co-exist with the crayfish.

Numerous invasive organisms are currently spreading outside of their natural habitat at an unprecedented rate, mainly due to human actions. As a result of this spread, various ecosystems have been altered and this fact seriously affects the balance of biodiversity.

More specifically, the spread of exotic predators is considered to be one of the major causes of population decline and species extinction on a global scale.

This is the case of the red swamp crayfish (Procambarus clarkii), a species native to the south of the USA and north Mexico, deliberately introduced by humans in several areas on all continents, including the Iberian Peninsula. "The first records of this invasive species were located in Extremadura and Andalusia in the seventies. From this date on, they have spread due to the number of wetland areas, to practically the whole of the Peninsula. P. clarkii is an active predator of numerous aquatic organisms, including amphibian larvae," the Spanish researcher Germán Orizaola from the University of Uppsala (Sweden) said, having published a study in the journal Ecology on the interaction between the two species.

The aim of his study was to examine whether the period of co-existence with the red swamp crayfish could influence in the type of defensive response developed by the larvae of the common frog (Pelophylax perezi).
An adult and larva of the Common Frog, Pelophylax perezi
Photo credit: David Perez.

"The study involved collecting recently laid P. perezi frogspawn in five locations in the south of Portugal. In two of them P. perezi has been co-existing with the red swamp crayfish for more than 30 years (populations of long-term coexistence), in another they have been sharing a habitat for 20 years (population of short-term coexistence), while the last two populations are found in an area which has not yet been colonized by the exotic predator (populations without coexistence)," adds the scientist.

The study consisted of an experiment developed in the Centre for Environmental Biology in Grândola (Portugal), where the larvae of the five populations were raised from tadpoles to metamorphosis in the presence or absence of the red swamp crayfish.

"We held them in aquariums with a compartment into which a red swamp crayfish was introduced, or it was left predator-less. We also fed the predators in these compartments with larvae so that they produced chemical signals indicative of predation which could be detected by the larvae in the experiment," Orizaola explains. Using this design of experiment, they analyzed the response, both of the behavior and the morphology of the P. perezi frogspawn in the presence and absence of the predator.

According to the scientist, the results reveal that the populations of these amphibians with a tradition of coexisting with the predator for 30 years (between 10 and 15 generations of frogs) present a pattern of activity that is totally different from the populations with less coexistence or no coexistence with the red swamp crayfish.

"A long coexistence with the predator generated extraordinarily reduced patterns of activity, even in the absence of the predator. This would help the larvae to go unnoticed, which would help to increase its chances of survival," Orizaola points out. On the other hand, the other populations were five times more active.

Bigger tails and bodies In terms of their morphology, the larvae of populations which have coexisted with the red swamp crayfish had deeper tails and bigger body volumes than the rest.

The researcher emphasizes that "these two responses would allow them on the one hand to direct the attacks of the predator to less vulnerable areas of their body like the tail fin and, at the same time, maintain a larger digestive area to counteract the potential negative effects of lowered activity."

This indicates that the presence of exotic predators can induce a rapid process of evolutionary change in invaded ecosystems. Until recently, it was considered that such evolutionary processes would only happen through slow accumulation of changes over exceptionally long periods of time.

Lastly, not all amphibians behave in the same way. Recent research reveals that various endemic species to the Iberian Peninsula, such as the Iberian Parsley Frog (Pelodytes ibericus), are incapable of responding to the presence of the red swamp crayfish, which increases its risk of extinction.

"Better knowledge of the magnitude and time scale of the evolutionary changes is the key to properly understanding the biological processes and for correct development of efficient conservation measures," concludes Orizaola.

Citation
 Nunes AL, Orizaola G, Laurila A, Rebelo R. Rapid evolution of constitutive and inducible defences against an invasive predatorEcology, 2014, 95 (5) DOI: 10.180/13-1380.1



Saturday, July 5, 2014

A Kuroiwa's leopard gecko subspecies described post-extinction

A member of the Goniurisaurus kuroiwae Group
Kuroiwa’s Leopard Gecko, Goniurosaurus kuroiwae is a eublepharid gecko endemic to the central part of the Ryukyu Archipelago of Japan, in the subtropical northwestern Pacific. It is isolated from the rest of its congeners occurring in southeastern continental China, northern Vietnam, and adjacent coastal islands, and the species represents the easternmost Old World member of the family. Because this species (or species complex) consists of a number of allopatric and apparently diagnosable divergent insular populations, and its classification has been controversal.

In the latest revision, its populations were combined into a single species comprising five extant subspecies: G. k. kuroiwae; G. k. orientalis; G. k. splendens; G. k. toyamai; and G. k. yamashinae. Grismer et al. (1999, 2002), adopted the evolutionary species concept, referred to each of these taxa as full species, and this taxonomic treatment has been widely accepted in the context of the recent trend of disuse of the subspecies rank by herpetologists.

However, Nakamura et al. (2014) believe that such changes in taxonomic rank are premature, because diagnostic characters originally proposed to define each of these taxa are few in number and, moreover, include those with highly variable character states. For example, yellow-brown to gold iris color was considered as one of the character states that discriminates G. k. yamashinae from the other subspecies whose irises are blood-red in color, but G. k. kuroiwae populations from Okinawajima and adjacent islets also include individuals with more or less yellow irises. They therefore prefer to take a conservative stance with respect to the taxonomic treatment of G. kuroiwae sensu lato by maintaining the framework of Grismer et al. (1994).

In a new paper Nakamura and colleagues (2014) describe a new subspecies of the Kuroiwa’s Leopard Gecko, Goniurosaurus kuroiwae yunnu, based upon remains from a midden after the population has apparently become extinct. The new taxon differs from the other conspecific subspecies in having a unique combination of osteological character states: in particular, the maxilla contains a posteriorly extended maxillary shelf and a scarcely inclined lateral wall above the posterior tooth row, and the frontal contains a widened anterior section and a laterally overhanging anterior part of lateral prefrontal facet, both of which differentiate this new subspecies from the morphologically most similar G. k. kuroiwae. The new subspecies, endemic to Yoronjima Island, may have gone extinct, together with several other amphibians and reptiles on the island. The extinction was most likely due to human-related deforestation and increased predation pressure from introduced weasels.

Citations
Grismer, L.L., Ota, H., Tanaka, S. (1994): Phylogeny, classification, and biogeography of Goniurosaurus kuroiwae (Squamata: Eublepharidae) from the Ryukyu Archipelago, Japan, with description of a new subspecies. Zool. Sci. 11: 319-335.

Grismer, L.L., Viets, B.E., Boyle, L.J. (1999): Two new continental species of Goniurosaurus (Squamata: Eublepharidae) with a phylogeny and evolutionary classification of the genus. J. Herpetol. 33: 382-393.

Grismer, L.L., Shi, H., Orlov, N.L., Ananjeva, N.B. (2002): A new species of Goniurosaurus (Squamata: Eublepharidae) from Hainan Island, China. J. Herpetol. 36: 217-224.


Nakamura, Y., Takahashi, A., & Ota, H. (2013). Recent cryptic extinction of squamate reptiles on Yoronjima Island of the Ryukyu Archipelago, Japan, inferred from garbage dump remains. Acta Herpetologica, 8(1), 19-34.

Skull morphology of some highly aquatic South American xenodontines

In all recently published molecular phylogenies, the South American Xenodontinae form a clade that comprises
several monophyletic units (tribes), one of which consists of the three genera of the tribe Hydropsini (Helicops,
Hydrops and Pseudoeryx. Complete information on the bony skull is available for nearly a third (29 genera) of the Dipsadidae genera, whereas fragmentary descriptions were published for an additional 29 genera. Information on the bony skull of Hydropsini is more complete, since descriptions are available for Helicops carinicaudus, H. infrataeniatus, Hydrops marti, H. triangularis, and Pseudoeryx plicatilis.

A comparison of the cranial osteology among the three Hydropsini genera may prove useful characters to discuss the systematic value of previously studied features and to identify new ones that could unravel relationships among species within the tribe.  Di Pietro and colleagues (2014) describe the bony skull variation of Helicops
infrataeniatus, H. leopardinus, Hydrops caesurus, and Pseudoeryx plicatilis and compare it to that of Dipsadidae
species. This comprehensive comparison includes terrestrial, semi-fossorial, fossorial, semi-aquatic,
fully-aquatic, and arboreal forms of Dipsadidae.

The authors compare them with several genera of Dipsadidae and found that the unpaired foramen on the parabasisphenoid with anterior position is the only skull feature shared by all Hydropsini genera. This feature also occurs in the semi-aquatic (Erythrolamphrus semiaureus) and fully-aquatic (Farancia abacura) dipsadids. All species of Hydrops with available skull descriptions and Pseudoeryx plicatilis share four features: (1) The anterior border of the angular is higher than the posterior border of the splenial, (2) the vomerine processes of the premaxilla are long, (3) the ascending process of the premaxilla overlaps the horizontal lamina of the nasals, and (4) an anterior projection of the prefrontal is present.

All species of Helicops with available skull descriptions and Pseudoeryx plicatilis share three features: (1) A vertical
lamina of the nasal with a notch, (2) a single foramen rotundum, and (3) the presence of a ventral projection of the
transverse crista of the basioccipital. Finally, they also found small, paired parietal foramina in most of the dipsadids studied here, which are filled with a Sudan-Black-positive tissue of possible nervous origin.

The species studied here and those for which are available skull descriptions, Helicops and Hydrops share no unique features. These authors found the two genera share a long and triangular-shaped maxillary process of the palatine,
a character not found in the species of Helicops and Hydrops reported on by previous authors.

Citation

Di Pietro, D. O., Alcalde, L., & Williams, J. D. (2014). New cranial characters in the tribe Hydropsini (Serpentes: Dipsadidae: Xenodontinae). Acta Herpetologica, 9(1), 1-14.

One opinion on the ban to import five constricting snakes left out of the 2012 decision

The following is an editorial opinion from News-pess.com.
What's your reaction to taking a trip to the Everglades National Park, one of the jewels showcasing America's natural beauty, and seeing a giant constrictor snake stretched across the road in the evening light?
If it's one of revulsion and sadness that these creatures don't belong here, you might want to make your voice heard as the federal government considers expanding a ban on such snakes.
In 2012, after taking public comment and looking at business and environmental analysis, the U.S. Fish and Wildlife Service deemed only four species of constrictors — the Burmese python, yellow anaconda, and the northern and southern African pythons — to be injurious wildlife. That meant those species could not be imported or taken across state lines.
That didn't stop the nightmare in the Everglades, where Burmese pythons — which can grow to 18 feet and weight 150 pounds — already are breeding and spreading. Rabbits, raccoons, opossums, bobcats and foxes, which once were common in the Everglades, now are rarely seen. Though it's impossible to definitively blame the pythons, the conclusion is a logical one.
Astoundingly, the United States Association of Reptile Keepers sued to overturn that watered-down ban, saying it would cripple a $100 million industry in sales of constricting snakes. The outcome of that suit is pending.
Now, the Fish and Wildlife Service is again considering a ban on five snakes omitted from the 2012 decision — including the boa constrictor, green anaconda, Beni anaconda, deSchauensee's anaconda and reticulated python. The green anaconda, the largest snake in the world, already has been seen in the Everglades. The boa constructor is established in Miami-Dade County.

Those in the snake trade offer a weak argument that cold weather will restrict the giant snakes to South Florida. But a recent survey showed that mangroves, which are cold-sensitive plants, are moving up Florida's coast as the climate warms. Is it unreasonable to expect that snakes would do the same?
The public comment period for the proposed ban ends July 24. To add your voice, go to federalregister.gov/a/2014-14712. This foolishness of importing such dangerous species has to stop.

Thursday, July 3, 2014

Chironius phylogeny

Chironius carinatus. JCM
Fourteen colubrid genera are known from South America: including  Chironius Fitzinger, 1826. This is one of the largest genera, with 16 species known to date. Its distribution ranges from the northern coast of Honduras to Uruguay and northeastern Argentina; and they are present in the Lesser Antilles. Chironius are long, slender, oviparous snakes that are mostly diurnal racers of terrestrial and arboreal habits. Most species inhabit lowland tropical rainforests, but also include humid montane forests and open formations. Dixon et al. (1993) made an extensive revision of Chironius and proposed the first morphological phylogeny of the genus, based mostly on hemipenial and external morphology. Their tree topology was not obtained using computer-based techniques, and no outgroup taxa were included in the study. Nevertheless, they discussed the affinities of Chironius with the other South American colubrid snakes, suggesting that Dendrophidion represents the sister-group.

Klaczko and colleagues present a phylogenetic hypothesis for 14species of the genus Chironius based on a combined molecular and morphological data matrix that includes one nuclear (c-mos) and two mitochondrial (12S and 16S) genes, and 37 morphological characters retrieved from scale, skull, and hemipenial features. They test the monophyly of the genus and provide additional evidence for its sister-group relationship within the South American radiation of colubrid snakes.

Phylogenetic relationships were inferred using maximum parsimony (MP) and maximum likelihood (ML). Their combined morphological and molecular analyses strongly support the monophyly of the genus Chironius and its sister-group relationship with a clade formed by the genera Dendrophidion and Drymobius. Phylogenetic relationships within the genus Chironius is still controversial, although five clades are retrieved with medium to strong support.

Their results corroborate three of the clades suggested by Dixon et al. (1993) (i.e. C. scurrulus and C. laevicollis; C. bicarinatus and C. flavolineatus; C. foveatus, C. multiventris, and C. laurenti). But, Dixon et al. (1993) retrieved the clade formed by C. scurrulus and C. laevicollis in the least inclusive position in their tree, whereas the combined analyses of Klaczko et al. reached the opposite result, with this clade in a basal position within the genus. Chironius laevicollis and C. scurrulus form a well-supported clade that corresponds to the most basal clade within Chironius in the MP combined analysis, and to the second most basal clade (including C. fuscus as their sister species) in the ML combined analysis. This clade is supported by seven unambiguous molecular synapomorphies, by the presence of lobular calyces in the hemipenis that gradually decrease towards the base of the organ, and by the absence of a bandeddorsal pattern in juveniles. The clade formed by C. vincenti, C. bicarinatus, and C. flavolineatus received only very low support values, but is corroborated by two unambiguous morphological synapomorphies: a Meckelian fossa delimited by the dentary and the splenial bones, and an anterior extension of the supratemporal that overlaps the parietal–prootic suture. Chironius bicarinatus and C. flavolineatus also form a poorly supported clade) defined exclusively by two unambiguous morphological synapomorphies: presence of apical pits restricted to the neck; and absence of a medial process in the prefrontal. Chironius laurenti, C. multiventris, and C. foveatus form a moderately supported clade defined exclusively by eight molecular unambiguous synapomorphies, whereas C. multiventris + C. foveatu form a clade supported by three molecular and one morphological synapomorphies.

Relationships with the genus Chironius remain controversial and more work needs to done on these interesting and widespread snakes.


Citations
Dixon JR, Wiest JA, Cei JM. 1993. Revision of Neotropical snake genus Chironius Fitzinger (Serpentes, Colubridae). Monografie XIII. Torino: Museo Regionale di Scienze Naturali.

Klaczko, J., Montingelli, G. G., & Zaher, H. (2014). A combined morphological and molecular phylogeny of the genus Chironius Fitzinger, 1826 (Serpentes: Colubridae). Zoological Journal of the Linnean Society. doi: 10.1111/zoj.12147.