Two new pit vipers discovered from Qinghai-Tibet Plateau

Two new species of venomous snakes were just added to Asia’s fauna – the Nujiang pit viper (Gloydius lipipengi) from Zayu, Tibet, and the Glacier pit viper (G. swild) found west of the Nujiang River and Heishui, Sichuan, east of the Qinghai-Tibet Plateau. Our team of researchers from the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences and Bangor University published the discovery in the open-access journal ZooKeys. In this study, we performed a new molecular phylogenetic analysis of the Asian pit vipers.

Guest blog post by Jingsong Shi

Two new species of venomous snakes were just added to Asia’s fauna – the Nujiang pit viper (Gloydius lipipengi) from Zayu, Tibet, and the Glacier pit viper (G. swild) found west of the Nujiang River and Heishui, Sichuan, east of the Qinghai-Tibet Plateau. Our team of researchers from the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences and Bangor University published the discovery in the open-access journal ZooKeys. In this study, we performed a new molecular phylogenetic analysis of the Asian pit vipers.

Glacier pit viper (Gloydius swild)

The Nujiang pit viper has a greyish brown back with irregular black ring-shaped crossbands, wide, greyish-brown stripes behind the eyes, and relativity short fangs, while the Glacier pit viper is blueish-grey, with zigzag stripes on its back, and has relatively narrow stripes behind its eyes.

Nujiang pit viper (Gloydius lipipengi)

Interestingly, the Glacier pit viper was found under the Dagu Holy-glacier National Park: the glacier lake lies 2000 meters higher than the habitat of the snakes, at more than 4,880 m above sea level. This discovery suggests that the glaciers might be a key factor to the isolation and speciation of alpine pit vipers in southwest China.

The stories behind the snakes’ scientific names are interesting too: with the new species from Tibet, Gloydius lipipengi, the name is dedicated to my Master’s supervisor, Professor Pi-Peng Li from the Institute of Herpetology at Shenyang Normal University, just in time for Li’s sixtieth birthday. Prof. Li has devoted himself to the study of the herpetological diversity of the Qinghai-Tibet Plateau, and it was under his guidance that I became an Asian pit viper enthusiast and professional herpetological researcher. 

Gloydius swild, the new species from Heishui, Sichuan, is in turn named after the SWILD Group, which studies the fauna and biodiversity of southewst China. They discovered and collected the snake during an expedition to the Dagu Holy-glacier.

A misty morning near the habitat of Glacier pit viper.

We are equally impressed by the sceneries we encountered during our field work: throughout our journey, we got to look at sacred, crystal-like glacier lakes embraced by the mountains, morning mist falling over the village, and colorful broadleaf-conifer forests. During our expedition, we met a lot of hospitable Tibetan inhabitants and enjoyed their kindness and treats, which made the expedition all the more unforgettable.

Research article:

Shi J-S, Liu J-C, Giri R, Owens JB, Santra V, Kuttalam S, Selvan M, Guo K-J, Malhotra A (2021) Molecular phylogenetic analysis of the genus Gloydius (Squamata, Viperidae, Crotalinae), with description of two new alpine species from Qinghai-Tibet Plateau, China. ZooKeys 1061: 87-108. https://doi.org/10.3897/zookeys.1061.70420

Guest blog post: Unique feeding behaviour of Asian kukri snakes gutting frogs and toads

Guest blog post by Henrik Bringsøe

In September 2020, we reported the first evidence for a newly discovered behaviour in snakes, as we provided extensive photographic documentation, demonstrating a macabre feeding strategy of Asian kukri snakes of the species Oligodon fasciolatus, the Small-banded Kukri Snake: a snake cutting open the abdomen of a toad, inserting its head and pulling out the toad’s organs which are then swallowed.

A Small-banded Kukri Snake attacking a Painted Burrowing Frog, which is inflating its lungs. The snake makes rotations about its own longitudinal body axis (“death rolls”), as it is biting and holding the belly of the frog. Video by Navapol Komanasin.

This is done while the toad is alive and it may take several hours before it dies! We have now provided new evidence that two other species of kukri snakes also exhibit this highly unusual behaviour: Oligodon formosanus, the Taiwanese Kukri Snake, and Oligodon ocellatus, the Ocellated Kukri Snake. These three species are closely-related and belong to the same species group in the genus Oligodon.

On two occasions in Hong Kong, a Taiwanese Kukri Snake was observed eviscerating frogs of the species Kaloula pulchra, the Painted Burrowing Frog or Banded Bullfrog. In one case, the snake had cut open the belly of the frog and inserted its head deep into the frog’s abdomen. In this position, the snake performed repeated rotations about its own longitudinal body axis, also called “death rolls”! We believe that the purpose of these death rolls was to tear out organs to be subsequently swallowed. In the other case, the organs of the frog had been forced out of its abdomen.

A Taiwanese Kukri Snake with its head buried deep into the abdomen of a Painted Burrowing Frog. Initially, the frog moves its long fourth toe of the left hind foot up and down 21 times. During the subsequent active struggle, the snake makes three “death rolls”. Video by Jonathan Rotbart.

A Small-banded Kukri Snake was also observed eating a Painted Burrowing Frog in Northeast Thailand, but it swallowed the frog whole. That snake also performed death rolls, although we have never before seen that behaviour in this species of kukri snake (this species was treated in our 2020 paper). This frog is not considered toxic and is also eaten by other snakes. We believe that prey size is crucial in determining whether the gape width allows large prey to be swallowed whole by kukri snakes. If the prey is too large, the snake may eviscerate a frog or toad, in order to swallow the organs. Afterwards, the snake will perhaps be able to swallow the rest of the frog or toad.

In another new paper, we describe and illustrate the Ocellated Kukri Snake eating the toxic toad Asian Black-spotted Toad (Duttaphrynus melanostictus) in Vietnam. Initially, the large snake’s head was buried past its eyes into the abdomen of the toad, but eventually the snake swallowed the toad whole despite its toxicity. We interpret this behaviour that kukri snakes are in fact resistant to the toads’ cardiac glycoside toxins. Furthermore, toads are only eviscerated if they prove too large to be swallowed whole.

An Ocellated Kukri Snake first pierced this poisonous Asian common toad and buried its head deeply into the abdomen of the amphibian, as it was probably eating the organs. However, as seen in the photo, the kukri snake proceeded to swallow the toad whole. 
Photo by James Holden.

We suggest that the unique behaviour of eviscerating frogs and toads and eating their organs may have evolved specifically in a group of kukri snakes named the Oligodon cyclurus group or clade because it has now been recorded in three of its species, namely Oligodon fasciolatus, Oligodon formosanus and Oligodon ocellatus. We hope that future observations may uncover additional aspects of the fascinating feeding habits of kukri snakes though we may indeed call them gruesome.

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See more video recordings of the snakes’ unique, even if quite gruesome, behaviours provided as supplementary files to one of the discussed research papers.

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Research papers: 

Bringsøe H, Suthanthangjai M, Suthanthangjai W, Lodder J, Komanasin N (2021) Gruesome twosome kukri rippers: Oligodon formosanus (Günther, 1872) and O. fasciolatus (Günther, 1864) eat Kaloula pulchra Gray, 1831 either by eviscerating or swallowing whole. Herpetozoa 34: 49-55. https://doi.org/10.3897/herpetozoa.34.e62688

Bringsøe H, Holden J (2021) Yet another kukri snake piercing an anuran abdomen: Oligodon ocellatus (Morice, 1875) eats Duttaphrynus melanostictus (Schneider, 1799) in Vietnam. Herpetozoa 34: 57-59. https://doi.org/10.3897/herpetozoa.34.e62689