Japanese giant salamanders have survived unchanged for millions of years. But these living dinosaurs face an uncertain future says Annisa Benrahal
Surely this doesn’t actually exist?” thought my nine-year-old self. I was at primary school, head down in an assignment to research and write about ‘an animal in which we were particularly interested’.
At nine, I was interested in nothing besides Pokémon, and that duly formed the basis of my research. I was going to study an animal as close to a Pokémon character as possible, and I knew exactly which one: the cute, charming, ‘fire-type’ known as Charmander.
That was how I came to find myself searching for images of giant salamanders – enormous, lizard-like amphibians with long bodies and short limbs, which I was convinced were actually Charmanders deep down. They were the strangest and most captivating creatures I had ever seen.
From my research, I concluded that ‘my’ Charmander lived in Japan, though back then I had no idea where Japan was. I printed out my pictures and presented them to my class, but nobody – not even the teacher – believed that something so prehistoric in appearance could still be inhabiting the Earth.
Fifteen years on and I’m wading through a cold, fast-flowing stream in the mountains of Tottori Prefecture in Japan. It is dark and my senses are suitably confused. My body is filled with adrenaline as I scramble over wet boulders, and the same thought from all those years ago is going through my mind: “Surely this doesn’t actually exist?”
It’s getting late, and given the recent spate of heavy rain, my tour-group members and I have yet to see any sign of the legendary creature we are hunting for. However, our guide, Richard Pearce, is confident that it is just a matter of time.
Sure enough, a few minutes later, I hear a cry of joy and I’m urged to hurry up. I stride through the water to catch up, then my body freezes and my mind recalls the same pictures I saw on my computer screen all those years ago. Nestled in the clear water, I see the huge body, the distinctively shaped feet, and the orange-and-brown camouflage colouration that almost causes us to miss the whole experience.
I’m staring down at the Japanese giant salamander, a creature so legendary that it was declared a Special Natural Monument of Japan in 1952). “It really does exist,” I thought.
What is the Japanese giant salamander?
Also known as the Japanese river monster, The Japanese giant salamander is a fully aquatic species and the second-largest amphibian in the world, after the Chinese giant salamanders.
Together with the hellbender in North America, they make up the Cryptobranchidae family.
How big are Japanese giant salamanders and how long do they live?
A cryptic nocturnal creature, the Japanese giant salamander can grow up to 1.5m in length and clock up a weight of 25kg, with a lifespan of up to 100 years.
Where do Japanese giant salamander live?
As its name suggests, the species is endemic to Japan, inhabiting the Chūgoku, Chūbu and Kinki regions of central and western Honshū, as well as Shikoku and north-eastern Kyūshū, where it makes a home in large rivers and their smaller tributaries, and shelters in holes in the riverbank or under rocks.
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How many Japanese giant salamanders are there in the wild?
Estimating Japanese giant salamander populations is difficult as data is thin on the ground, but one thing we do know is that this prehistoric giant has remained virtually unchanged for 23 million years. Search for any image of primitive amphibians and you’ll be astonished by the resemblance to these modern creatures.
What do Japanese giant salamanders eat?
Japanese giant salamanders are sit-and-wait predators. They lurk in the shallows, waiting for passing prey to stumble along, then employ the hunting method of suction-feeding. I was lucky enough to witness this first-hand during my tour – an unwitting fish headed straight for the salamander’s jaws and vanished in the blink of an eye.
These are clever feeders indeed, well-adapted to bag themselves a meal with precious little effort. They can detect when prey is approaching thanks to sensory cells on their skin that pick up vibrations in the water, and their vast mouths can suck in fish, crabs or even small mammals, which are simply gulped down whole. What’s more, the left and right sides of a salamander’s jaws can move independently, allowing these amphibians to efficiently capture and manipulate prey. No other species on Earth shares this unique feeding strategy.
How do Japanese giant salamanders mate?
When breeding season rolls in, both males and females move upstream. Large dominant males, known as ‘den masters,’ establish nest-sites to entice a mate, keeping these lairs meticulously clean and protected from rival males. A female attracted to a nest will enter and lay her eggs, while the resident male releases his sperm.
Why male Japanese giant salamanders make excellent fathers
Male Japanese giant salamanders make excellent fathers. In most salamander species, parental duties are usually performed by the females. However, even the toughest and fiercest male Japanese giant salamander may spend up to seven months of the year caring for his offspring. In addition to guarding the nest, he fans the eggs with his tail to maintain constant oxygen flow, and eats any dead eggs, preventing the contamination of his healthy offspring.
What threats do Japanese giant salamanders face?
Japanese giant salamanders are deserving of their status as a national treasure, but these elusive creatures face an uncertain future. In 2022, their conservation status was upgraded by the IUCN from Near Threatened to Vulnerable.
Like a host of other river-dwelling animals, one of the main reasons for their demise is habitat fragmentation. Salamanders are being prevented from travelling upstream to breed by the construction of concrete weirs and dams, along with other human-made flood-prevention reinforcements, which block their movements upstream.
Water pollution is another threat for a creature that breathes through its skin (and thus relies on oxygen in the water), as is the increase of extreme weather events, such as rainstorms and flooding, which can sweep salamanders out of rivers and into the ocean.
As if that’s not enough, there’s the challenge posed by the introduction of a closely related species. In 1972, approximately 800 Chinese giant salamanders were brought to Japan with the intention of selling their meat as a delicacy, a practice that has been banned for its protected Japanese cousin.
Many of these newcomers ended up in river courses throughout the country, and the species is now considered invasive, with genetic studies revealing extensive crossbreeding between Chinese and Japanese populations. Research conducted from 2011 to 2013 by scientists at Hiroshima University found that 98 per cent of the giant salamanders in the Kamogawa river system in Kyoto, once a stronghold of the Japanese giant salamander, are in fact hybrids. These hybrid individuals are outcompeting the native species, which could potentially lead to its extinction.
Could the Japanese giant salamander be saved from extinction?
Despite the gloom, there is some hope for these prehistoric marvels, because they have Richard, who has devoted his life to saving these magnificent creatures and protecting their entire habitat. “We know Japanese giant salamanders are in trouble, even though we don’t have data showing the decline,”
he says. “Their situation here is dire and time is running out… I honestly feel that if I don’t do something practical, something real to save them, then no one will.”
Originally from Gloucestershire, Richard has been living in Japan for more than a decade and has witnessed the continued degradation of the salamanders’ habitat. In 2021, he set up the non-profit organisation Sustainable Daisen to raise awareness of the species’ plight in the Nawa River Basin. Richard believes that ecotourism is essential in securing the future of these special animals. He runs viewing and conservation tours – on the latter, guests accompany a leading salamander scientist and help collect data.
“People come from all over the world to see these giants,” he says. “They aren’t interested in anime, or the shrines, or anything else related to Japan. They’re only here for the salamanders”. For amphibian enthusiasts, these living dinosaurs are a bucket-list species, bringing ecotourism dollars into depressed rural areas. “Showing local people and authorities that keeping these amazing animals alive is of economic benefit may be their only and best chance of survival,” says Richard.
Seeing giant salamanders in this part of the country is special in itself. Not only is the ecology unique – nowhere else in Japan do the amphibians breed so close to the coast, and at such low altitudes (less than 100m) – but there is a huge cultural significance interwoven into the landscape.
The Nawa River Basin sits in the foothills of Mount Daisen, which, at 1,729m tall and shrouded in beech forest, is the highest peak in Tottori. As a sacred site long revered as a home of gods, the area around the peak of Daisen has been left undisturbed, its intact forests filtering water as it trickles into streams, creating the clean, oxygen-rich habitat the salamanders need.
Richard works with international researchers to collect population data, as well as record the impact of weirs and dams, and assess the quality of river water. “It is our hope that the government will start taking the problems facing the salamanders as seriously as we believe they need to, after reading our recommendations,” he says. In the meantime, with the help of volunteers and with special permission, he has built temporary bypass slopes over a number of weirs in a salamander-rich area of Daisen town, to grant the amphibians passage upstream. Ideally, these structures will become permanent in time.
I sometimes wonder, if I had to go back to my primary school days, what I would have told myself about the existence of Charmanders. Would I have let my nine-year-old self down by telling her that Pokémon characters do not exist in real life, and cannot, in fact, breathe fire? Or that Charmander is actually based on a real animal, but one that faces a high chance of becoming extinct?
On reflection, what I think I’d tell her is something more helpful. I’d tell her that there’s an even cooler creature than Charmander. It’s double the size, can suck in prey in the blink of an eye, and is a prehistoric marvel whose family is around 23 million years old. And what’s more, it really does exist.