“Baffling” New Species of Snake Discovered in Myanmar

Scitech Daily ^ | JANUARY 28, 2024 | PENSOFT PUBLISHERS

[Red Badger]

The Ayeyarwady pit viper, a new species discovered in Myanmar by Dr. Chan Kin Onn, illustrates the complexities of species differentiation in pit vipers. This species, which displays traits of both the redtail and mangrove pit vipers, was initially thought to be a hybrid but was confirmed as distinct through genomic analysis. Credit: Wolfgang Wüster

Finding and describing new species can be a tricky endeavor. Scientists typically look for distinctive characters that can differentiate one species from another. However, variation is a continuum that is not always easy to quantify. At one extreme, multiple species can look alike even though they are different species—these are known as cryptic species. At the other extreme, a single species can be highly variable, creating an illusion of being different species. But what happens when you encounter both extremes simultaneously?

Herpetologist Dr Chan Kin Onn (previously at the Lee Kong Chian Natural History Museum, Singapore, now with the University of Kansas Biodiversity Institute and Natural History Museum, USA) led a study describing a new species of pit viper from Myanmar that is both similar and different from its sister species. The discovery is published in the open-access journal ZooKeys.

Challenges in Differentiating Asian Pit Vipers “Asian pit vipers of the genus Trimeresurus are notoriously difficult to tell apart, because they run the gamut of morphological variation. Some groups contain multiple species that look alike, while others may look very different but are actually the same species,” they say.

The redtail pit viper (Trimeresurus erythrurus) occurs along the northern coast of Myanmar and is invariably green with no markings on its body. A different species called the mangrove pit viper (Trimeresurus purpureomaculatus) occurs in southern Myanmar. This species typically has distinct dorsal blotches, and incredibly variable dorsal coloration including gray, yellow, brown, and black, but never green. Interestingly, in central Myanmar, sandwiched between the distribution of the redtail pit viper and the mangrove pit viper, a unique population exists that is green with varying degrees of blotchiness, which appears to be a blend between the redtail pit viper and the mangrove pit viper.

A specimen of Trimeresurus ayeyarwadyensis from Meinmahla Kyun Wildlife Sanctuary, Pyapon District, Ayeyarwady Region in Myanmar. Credit: Hla tun

Initial Hypothesis and Genomic Revelation “This mysterious population in central Myanmar baffled us and we initially thought that it could be a hybrid population,” the researchers said. In a separate paper, Dr Chan used modern genomic techniques and determined that the population in central Myanmar was actually a distinct species and not a hybrid population.

But this was not the end of the story. The researchers discovered another surprise when they examined the snake’s morphological features: they found that the new species was also highly variable. Certain populations are dark green with distinct blotches, easily distinguishable from its closest relative, the redtail pit viper, which is bright green with no blotches. However, some populations of the new species are bright green with no blotches and look virtually identical to the redtail pit viper.

“This is an interesting phenomenon, where one species is simultaneously similar and different from its closest relative (the redtail pit viper). We think that at some point in the past, the new species may have exchanged genes with the redtail pit viper from the north and the mangrove pit viper from the south,” says Dr Chan.

The new species is called the Ayeyarwady pit viper (Trimeresurus ayeyarwadyensis) in reference to the Ayeyarwady River, which is the largest and one of the most important rivers in Myanmar. The river forms an expansive delta that is bounded by the Pathein River to the west and the Yangon River to the east. These rivers and their associated basins also mark the westernmost and easternmost distribution boundaries of the Ayeyarwady pit viper.

References:

“A new species of pit-viper from the Ayeyarwady and Yangon regions in Myanmar (Viperidae, Trimeresurus)” by Kin Onn Chan, Shahrul Anuar, Ananthanarayanan Sankar, Ingg Thong Law, Ing Sind Law, Rasu Shivaram, Ching Christian, Daniel G. Mulcahy and Anita Malhotra, 13 December 2023, ZooKeys.

DOI: 10.3897/zookeys.1186.110422

“The Artefactual Branch Effect and Phylogenetic Conflict: Species Delimitation with Gene Flow in Mangrove Pit Vipers (Trimeresurus purpureomaculatus-erythrurus Complex)” by Kin Onn Chan, Daniel G Mulcahy and Shahrul Anuar, 21 July 2023, Systematic Biology.

DOI: 10.1093/sysbio/syad043

[Zhang Fei]

There are probably downsides，but some animals are resistant to snake venom

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[Drabeck wasn’t surprised by these mutations, but she was surprised when she compared the honey badger’s tweaks to those found in other mammals. These tweaks had evolved independently in at least four species: honey badgers, mongooses, hedgehogs, and pigs. The hedgehog—which loves to eat venomous snakes—wasn’t a surprise. But the pig? “We were pretty excited by that,” says Drabeck. She hadn’t expected pigs to have molecular defenses against venom; biologists knew wild pigs could survive snakebites but assumed that was because their thick skin and fat acts like armor against fangs. But wild pigs, like honey badgers, have long shared the same parts of the world as venomous snakes—giving them an incentive to evolve venom resistance. And that in turn has given the snakes an incentive to evolve more toxic venom.]

[READINABLUESTATE]

Sorry, I was just referring to the bitey ones.

[thesligoduffyflynns]

you must know your snakes well!

ok, heres my question obviously, theres mmore than one snake in this group, but what is it that classifies them as “ pit”? ,
ive never heard of that & would like to expand my knowledge bank🙋

[Olog-hai]

Well, pit vipers have little heat-sensing “pits” on either side of their face; on this rattlesnake, the pit is visible on the lower part of the face between the eye and the nostril. The snake uses them to detect body heat from prey or possible threats.

[RitchieAprile]

Looks like a vambu viper..

[Salamander]

God made a new snek.
Film at 11.

[SunkenCiv]

Thanks Red Badger. Apparently this viper had dodged identification until recently.

[Red Badger]

[ComputerGuy]

My family was stationed in Bangkok in the early sixties. Around our house we had Russell’s Vipers, Banded Kraits and Cobras.

[Texan5]

That is a beautiful snake-but I will only admire it from a distance-preferably in a zoo...

[Red Badger]

behind thick glass.....................