Amphibians
Chinese Giant Salamander
Andrias davidianus · also called Chinese giant salamander, infant fish, wa wa yu
The Chinese giant salamander is the biggest amphibian alive — a metre or more of flat-headed, wrinkled, slow-moving predator that lives on the bottom of cold mountain streams and has done so, almost unchanged, since before the end of the age of dinosaurs. It is also one of the most endangered animals on Earth, hunted to the edge of extinction for a luxury food market.
Overview
The species historically lived in clear, cold, fast-flowing rivers and streams in the mountains of central and southern China, in the drainages of the Yangtze, Yellow, and Pearl rivers, from the lowlands up to about 1,500 metres. It is entirely aquatic, sheltering by day in underwater cavities and rock crevices and emerging at night to hunt. It needs water that is cool and highly oxygenated, because it breathes largely through its skin.
A giant that breathes through its skin
The giant salamander has small, weak lungs and instead absorbs most of its oxygen across the frilled folds of skin running along each side of its body, which increase the surface area in contact with the water. It moves the folds gently to keep fresh water flowing over them. This makes the animal utterly dependent on cold, clean, moving water — warm or stagnant or silty water suffocates it, which is one reason dams and pollution have been so devastating.
Hunting in the dark
With tiny eyes set on top of a broad head, the giant salamander is nearly blind and hunts by other means. It detects prey by smell and by a network of sensory nodes across its skin that register the faint water movements made by a passing fish or crab. When something comes within range it makes a sudden sideways lunge and snaps, gulping the prey whole with a mouth that spans the full width of its head. It eats fish, crustaceans, amphibians, insects, and smaller salamanders.
A living fossil
The giant salamander family has existed for roughly 170 million years, and its members have kept the same basic form throughout. Fossil relatives are known from Europe and North America; one, described in the 1700s, was famously mistaken for the skeleton of a human drowned in the biblical flood. Today the family is down to the Chinese and Japanese giant salamanders and the hellbender.
An animal being eaten to extinction
The Chinese giant salamander is Critically Endangered. It is prized as a delicacy and a supposed health food, and decades of hunting stripped it from most rivers. A large farming industry now supplies the food market, but this has not saved the wild animal: farms draw on wild-caught stock, releases have spread a lethal iridovirus and scrambled the genetics of local populations, and recent studies show that what was called one species is in fact several, some possibly already gone from the wild. Saving it now depends on protecting the few genuinely wild populations that remain and keeping farm and wild animals apart.
Chinese Giant Salamander: common questions
How big is the Chinese giant salamander?
It is the largest amphibian in the world. Most adults are around a metre long, but the largest reliably reported individuals reached about 1.8 metres and roughly 60 kilograms — the size of an adult person. It has a broad, flattened head, tiny lidless eyes, a paddle-like tail, and heavily wrinkled skin. Its close relative the Japanese giant salamander is slightly smaller, and the North American hellbender, in the same family, tops out at about 70 centimetres.
Why is the Chinese giant salamander called a living fossil?
Its family, Cryptobranchidae, appears in the fossil record largely unchanged for around 170 million years, meaning the giant salamanders of today look much like their relatives did when dinosaurs such as Stegosaurus were alive. The body plan — large, flat-headed, fully aquatic, skin-breathing — has worked without major modification for an immense span of time, which is why biologists use the "living fossil" label, even though the animals have of course continued to evolve in smaller ways.
Why is it Critically Endangered when there are millions on farms?
China has a large industry farming giant salamanders for luxury food, and well over a million animals may be in captivity. But wild populations have collapsed from overhunting, dam building, pollution, and habitat loss, and surveys across huge areas of former range now find almost no wild salamanders at all. Farm releases have spread disease and mixed together animals from different regions, and recent genetic work shows the "Chinese giant salamander" is actually several distinct species, at least one of which may already be extinct in the wild.
Is the Chinese giant salamander dangerous to people?
Not seriously. It has a wide mouth and can deliver a strong, surprising bite if grabbed or stepped on, and its skin secretes a sticky, irritating mucus as a defence, but it is not venomous and it does not hunt anything remotely person-sized. The far greater danger runs the other way — the species' decline is driven almost entirely by human demand for it as food.