The world’s largest amphibian should have been easy to find.
While most salamanders are the size of your finger, Chinese giant salamanders can be as big as your entire body. Even average individuals can grow to Labrador size. Their heads are broad and flattened, their eyes are small and lidless, and their bodies look like something you might find left behind in a toilet. Their skin has the color of a brownie and the texture of a wet prune. When disturbed, they make a noise that sounds uncannily like a crying baby; in Chinese, their common name translates to “infant fish.”
In five years of searching, Andrew Cunningham and his 80-strong team of surveyors barely heard that noise. In what is possibly the largest wildlife survey ever conducted in China, they scoured 50 sites in the Chinese provinces where these behemoths once thrived. They swept rivers and streams with their headlamps. They flipped over rock after rock. They put out bait. But after all that effort, they found just 24 individuals. And genetic analyses suggest that most of these—maybe even all—had escaped or been released from farms.
The team can’t be sure if any wild individuals still exist. “It’s awful,” Cunningham says. “It’s a really sad story.”
These giants are part of the oldest lineage of salamanders, which separated from the others around 170 million years ago—a time before flowers and birds, before Brontosaurus and Stegosaurus. There are only two other surviving species from this ancient lineage: one from Japan, and the hellbender salamander from the eastern United States. All of them are in decline, but the Chinese giant salamander is especially so.
In past surveys, it took an hour of searching to find one Japanese giant salamander, and two hours to find a hellbender. By contrast, it took Cunningham’s team 16 weeks to find each Chinese giant salamander. The team interviewed more than 2,800 people who live in what should be salamander habitat, and most hadn’t seen the animals for decades.
This tragedy is even greater than it first seems. Based on analyses of the salamanders’ DNA, the team thinks that it’s not just one species, but five. They all look superficially similar, but they’ve been evolving separately for between 4 and 10 million years. And now, all five of them face imminent extinction in the wild.
Until the 1970s, the salamander was common throughout China’s Qinling Mountains. Thanks to its baby-like cry, local people thought that eating it would bring bad luck. But immigrants from the south, arriving in the wake of the Cultural Revolution, had no such compunctions. They harvested the salamander in huge numbers, often using toxic insecticides to immobilize the creature. And when natural populations plummeted, they started farming it, for use in soups, stews, and several other dishes. There’s even a salamander jelly.
From 2004 onward, the number of farms grew rapidly. The government encouraged them as a way of boosting the fortunes of otherwise poor rural areas. Official licenses were issued, but many farms ran illicitly. By 2011, they held around 2.6 million salamanders between them. In some counties, salamander farming became the main industry.
Bizarrely, only 3 percent of the animals raised by the farms are eventually sold to restaurants. The rest are sold to more start-up farms. This absurd amphibian Ponzi scheme so inflated the worth of the salamanders that a small, 2-kilogram individual could sell for around $1,500. As a result, people began supplementing the farmed stock by illegally collecting the animals from the wild. “The high prices created a sort of salamander rush,” says Jing Che from the Kunming Institute of Zoology, who was involved in the recent study.
Many of these details only came to light after a 2010 workshop, in which Chinese and Western conservationists jointly realized that they knew very little about the burgeoning industry. By the time they learned just how massive it was, it was already too late, as evidenced by the mostly fruitless nature of their subsequent five-year survey.
To make matters worse, they simultaneously realized that the vanishing species was actually five. The Canadian researcher Robert Murphy found hints of this diversity back in 1991, but due to limited funding and restrictions on foreign researchers, he couldn’t follow up on them. Almost 20 years later, he teamed up with Che and others to collect tissue samples over 1,000 salamanders, and analyze their DNA. They found that these animals belonged to at least five separate lineages, and perhaps eight or more. According to the team, all five are distinct enough to qualify for species status.
There’s no settled way of defining what a species is, let alone how different two lineages have to be to count as distinct species. But Samuel Turvey from the Zoological Society of London, who worked on the study, says that “the level of genetic differentiation between the Chinese giant salamander lineages is comparable to that seen between other closely related amphibian species.”
Each of the five lineages also inhabits a separate river system, and since these animals don’t move very far, they’ve all been evolving independently for between 4 and 10 million years. “It always seemed possible that multiple species might exist,” says Che.
“This is very common with amphibians,” says Ariadne Angulo, who co-chairs the amphibian group of the International Union for the Conservation of Nature. There are many other cases where a single, wide-ranging species turned out to be several hidden ones. Those differences have big implications. When conservationists try to predict an animal’s fate, and thus how much effort should be put into saving it, “it’s based on the premise that you’re assessing one species,” says Angulo. “If it’s actually five, obviously their extinction risk is going to be very different.”
“With millions of years of divergence between the groups, my expectation is that these animals have adapted to their surroundings,” says Amy McMillan from Buffalo State University, who studies the related hellbenders. “If we mix them up with other genetic lines, we don’t really understand what that would do.”
The farms have essentially done that experiment: By trading giant salamanders across their entire range, they’ve created millions of hybrids. Thousands of these have made their way into the wild because the Chinese government, in a bid to conserve the species, pays farmers to release some of their stock. “They do that without knowledge of where the salamanders have come from, or of their genetics,” Cunningham says. “Their heart is in the right place but the methodology is very flawed.”
“Farms are releasing salamanders from the north, which gets very cold winters, into the south, which is subtropical,” adds Che. “It’s possible that cold-adapted genes from the north will be maladaptive in the south.” The various populations might also cross-breed, homogenizing the salamander gene pool and driving some lineages to extinction. This is already happening: All the individuals that the team recently caught from the Pearl and Yangtze rivers carry the DNA of the northern Yellow River lineage, rather than the indigenous salamanders that once lived in those waters.
As a group, amphibians aren’t doing very well. Of the 7,000 known species in the world, around a third are threatened and almost half are in decline, thanks to shrinking habitats, changing climates, and a killer fungus. “The dogma is that there are no amphibian declines anywhere in Asia,” says Karen Lips from the University of Maryland. “But I think that’s because people haven’t gone out and done the work. This [salamander study] clearly shows a pretty massive decline across very large scales.”
Why should anyone care? “This is a top predator in the freshwater ecosystems of China—a country that has problems with providing enough fresh water for its growing population,” says Cunningham. “We don’t yet know what the salamander’s removal will do, but it will do something.”
He notes that there are still plenty of individuals in farms, but they aren’t the answer to the species’ woes. Around 72,000 have already been released, and there’s no evidence that they are thriving in the wild. The captive populations might not be around for long either. Many are riddled with disease. Second-generation individuals don’t seem to breed in captivity, possibly because they weren’t reared properly. And many farms are closing down because the salamander pyramid scheme collapsed a year or two ago.
Che still hopes that the remaining farms can do some good. “We believe they should breed and release the local species only,” he says. “It’s also important to engage local people in conservation efforts to slow the poaching.”
But Cunningham is not optimistic. “Just one conservation breeding program is a huge ask, but to do one for each of the five species?” he says. “We’ve got to try but it’ll be extremely difficult. And even if we get down that route, I think hand on heart, we can’t say what the ecological needs of these lineages are unless we can find them in the wild.”