Seen coiled around a branch in an undated picture, a new species of snake called the ruby-eyed green pit viper (Cryptelytrops rubeus) has been discovered in Southeast Asia, according to a recent study. The snake lives in forests near Ho Chi Minh City and across the low hills of southern Vietnam and eastern Cambodia's Langbian Plateau.
Scientists collected green pit vipers from Thailand, Laos, Vietnam, and Cambodia between 1999 and 2003 and examined them in the lab, using physical characteristics and genetics to identify new species.
"We know this species from only a few specimens, and very few people in the world have seen this snake," said study co-author Anita Malhotra, a molecular ecologist at Bangor University in the U.K. "We know very little about what it does, to be honest."
Malhotra and colleagues also discovered a very similar species with striking yellow eyes (not pictured) dubbed the Cardamom Mountains green pit viper (Cryptelytrops cardamomensis), which inhabits southeastern Thailand and southwestern Cambodia. Both new species were described in the January 23 issue of the journal Zootaxa.
Photograph by Jeremy Holden
Out to Lunch
A large frog proved to be more than a mouthful for a ruby-eyed green pit viper, which abandoned its meal just after this undated picture was taken. Whether the newfound snake was disturbed by the camera flash or simply bit off more than it could chew isn't known.
In general, the new species' eating preferences have been hard to uncover, scientists say.
"It's very difficult to get information on what these things eat,” study co-author Malhotra said. “Snakes are so good at digesting things, that what's left in their feces—if you can even collect any—is only a few very hard-to-digest bits, like hair from mammals or scales and claws from reptiles.
"Frogs are so easy to digest that there is literally nothing left."
Photograph by Jeremy Holden
Spot the Snake
A ruby-eyed green pit viper blends in with the vibrant jungle vegetation of Vietnam in a May 2000 picture.
Life in the trees is one reason the pit viper is so efficient at digesting its meals: A full gut would be a hindrance to movement aloft.
But the new species "do occur on the ground and often forage on the ground," study co-author Malhotra added. "And they often occur near streams, so one assumes that they do eat some high proportion of frogs.
"We also know that other related species eat small mammals, and these closely related animals are likely to be quite similar ecologically."
Photograph by Peter Paul van Dijk
A ruby-eyed green pit viper raises its head in southern Vietnam’s Cat Tien National Park in May 2000. The park is a stronghold for the new snake species, which inhabits a rather small geographic range where pressures on forests are high, Malhotra said.
It's not known how well the snake might adapt to other habitats, so it's not clear whether the ruby-eyed green pit viper should be considered an endangered species. But Malhotra and colleagues hope the snake doesn’t fall victim to status-seeking collectors of rare animals.
Rubies, as the snakes are called, "might be very vulnerable to that," she said, "because it's such a beautiful species."