The Ayeyarwady pit viper, a brand new species found in Myanmar by Dr. Chan Kin Onn, illustrates the complexities of species differentiation in pit vipers. This species, which shows traits of each the redtail and mangrove pit vipers, was initially regarded as a hybrid however was confirmed as distinct by means of genomic evaluation. Credit: Wolfgang Wüster
Finding and describing new species is usually a difficult endeavor. Scientists sometimes search for distinctive characters that may differentiate one species from one other. However, variation is a continuum that isn’t at all times simple to quantify. At one excessive, a number of species can look alike though they’re totally different species—these are often known as cryptic species. At the opposite excessive, a single species may be extremely variable, creating an phantasm of being totally different species. But what occurs once you encounter each extremes concurrently?
Herpetologist Dr Chan Kin Onn (beforehand on the Lee Kong Chian Natural History Museum, Singapore, now with the University of Kansas Biodiversity Institute and Natural History Museum, USA) led a examine describing a brand new species of pit viper from Myanmar that’s each related and totally different from its sister species. The discovery is revealed within 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 are saying.
The redtail pit viper (Trimeresurus erythrurus) happens alongside the northern coast of Myanmar and is invariably inexperienced with no markings on its physique. A distinct species referred to as the mangrove pit viper (Trimeresurus purpureomaculatus) happens in southern Myanmar. This species sometimes has distinct dorsal blotches, and extremely variable dorsal coloration together with grey, yellow, brown, and black, however by no means inexperienced. Interestingly, in central Myanmar, sandwiched between the distribution of the redtail pit viper and the mangrove pit viper, a novel inhabitants exists that’s inexperienced with various levels of blotchiness, which seems to be a mix 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 stated. In a separate paper, Dr Chan used fashionable genomic strategies and decided that the inhabitants in central Myanmar was truly a definite species and never a hybrid inhabitants.
But this was not the top of the story. The researchers found one other shock after they examined the snake’s morphological options: they discovered that the brand new species was additionally extremely variable. Certain populations are darkish inexperienced with distinct blotches, simply distinguishable from its closest relative, the redtail pit viper, which is vibrant inexperienced with no blotches. However, some populations of the brand new species are vibrant inexperienced with no blotches and look just about similar 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 known as the Ayeyarwady pit viper (Trimeresurus ayeyarwadyensis) in reference to the Ayeyarwady River, which is the most important and some of the essential rivers in Myanmar. The river kinds an expansive delta that’s bounded by the Pathein River to the west and the Yangon River to the east. These rivers and their related basins additionally 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
