Scientists have discovered a new species of giant salamander, believed to be the world’s largest amphibian.
Chinese giant salamanders, which are critically endangered and can grow to nearly 2m long, were previously thought to be of a single species until new research revealed not one, but three different genetic lineages.
The three varieties – Andrias davidianus, Andrias sligoi and another new discovery yet to be named – are genetically different enough to represent separate species, analysis by the Zoological Society of London (ZSL) and Natural History Museum found.
A. davidianus is the species previously known to science, while A. sligoi is a newly-differentiated variety. Analysis of a 74-year-old A. sligoi specimen that once lived at London Zoo revealed its distinct genetic code and it is this species that is thought to be the largest of the three.
Sixteen other specimens collected in the early 20th century were also examined.
“It’s amazing in this day and age that it took until now to work out what the world’s largest amphibian is,” the study’s lead author Samuel Turvey, a conservation scientist at ZSL, told National Geographic.
Giant salamanders, which typically live in rocky, mountainous river systems, were once widespread across central, southern and eastern China.
Scientists concluded that Chinese giant salamanders diverged into three distinct species between 3.1 and 2.4 million years ago, which coincides with a period of mountain formation when the Tibetan plateau rose rapidly.
But their meat is considered a delicacy in China and they have historically been used for medicinal purposes, which has created a vast farming industry. Habitat loss and poaching also pose severe threats.
While millions are now kept on farms, these appear to overwhelmingly be members of the most common species, while wild populations are at great risk of extinction.
“These findings come at a time where urgent interventions are required to save Chinese giant salamanders in the wild,” said Melissa Marr, a PhD researcher at the Natural History Museum.
The new discoveries shed light on the possibility that previous conservation efforts to release farmed salamanders into the wild would have had a negative impact upon wild populations of the other species, increasing the risk of disease, competition and genetic hybridisation.
“Our results indicate that tailored conservation measures should be put in place that preserve the genetic integrity of each distinct species,” Ms Marr said.
In 2016, London Zoo welcomed four young giant salamanders seized by border police after someone tried to illegally import them into the UK.
Three are still being cared for behind the scenes while one, named Professor Lew, can be seen by the public. Zookeepers hope to one day introduce another animal to Professor Lew as a mate.
Scientists believe that in light of the recent study, published on Monday in Ecology and Evolution, future conservation efforts could involve screening farmed giant salamanders to determine their species before encouraging them to mate and reintroducing them into the wild among their own species.
Dr Turvey added: “We hope that this new understanding of their species diversity has arrived in time to support their successful conservation, but urgent measures are required to protect any viable giant salamander populations that might remain.”
Additional reporting by PA
