Measuring 1.8 meters (6 feet) in length and weighing 63 kilograms (140 pounds), the Chinese giant salamander’s ancestors have roamed the Earth for the last 170 million years. Today's species (Andrias davidianus) was once plentiful across the country, but now it could very well be on its way to extinction.
The docile amphibian is the largest on Earth and, until recent history, they were left pretty much alone. A demand for salamander meat in the 1970s paired with the destruction of their habitat has caused an estimated 80 percent population decline in the last 50 years.
"The overexploitation of these incredible animals for human consumption has had a catastrophic effect on their numbers in the wild over an amazingly short time span," said Samuel Turvey with the Zoological Society of London in a statement.
Researchers surveyed 97 sites over the course of four years and were unable to confirm any wild salamanders at any survey site. What they did find is more disheartening: Nearly a quarter of the sites had evidence of illegal traps, bow hooks, and evidence of electro-fishing and poison.
In a second study, researchers used tissue samples and genetic analyses to determine that China’s giant salamander is not one species but at least five. Unfortunately, the measures meant to save the species could be contributing to their extinction. China has taken to commercial farming to replenish, grow, and ultimately reintroduce the giants to their historic numbers, but they didn’t account for these other species. Despite best intentions, conservationists were likely breeding the Yellow River species with local populations, hybridizing and homogenizing the species.
The results weren’t totally unexpected. Andrias davidianus can’t move across land and living in different unconnected river systems gave them the opportunity to diverge over time.
“We were not surprised to discover more than one species, as an earlier study suggested, but the extent of diversity – perhaps up to eight species –uncovered by the analyses sat us back in our chairs," said Jing Che from the Kunming Institute of Zoology, Chinese Academy of Sciences. "This was not expected."
Some of the five species may already be extinct in the wild. Researchers say their discovery highlights the importance of properly identifying species, especially when it comes to breeding and reintroducing other endangered species. Going forward, advances in genetic testing, classification, and technological differentiation could save other at-risk species.
But whether it’s too late for the giant salamanders remains to be seen. The researchers say maintaining Chinese giant salamander populations under current management is unlikely, but immediate protections and enforcements are equally unlikely.
Both studies were published in Current Biology.
3
