A Monster Opportunity - Conservation International

A Monster Opportunity 

 
Japanese Giant salamander (Andrias japonicus), Japan
© PETER SCOONES / www.naturepl.com 
Rob McNeil 
 

Everything in Japan seems to exist in a sort of amplified reality—everything is a little brighter, newer and more colorful than the “western” world.

And one creature in particular does nothing to make our visit seem less like a science fiction movie. The Japanese giant salamander (Andrias japonicus), also known as the Hanzaki, is the second largest amphibian on Earth. Japanese giant salamanders regularly measure up to 1.5 meters (five feet) in length, and are second in size only to their close relation the Chinese giant salamander (Andrias davidianus). The Chinese animals can reach a colossal 1.8 meters (approximately six feet) in length and weigh up to 65 kilograms (close to 140 pounds).

As Japan prepares to host the Convention on Biological Diversity later this year—a major conference where nations will come together to try to stop the global extinction crisis by agreeing to take steps to protect the world’s declining species—few creatures could be more emblematic of Japan’s own extraordinary, fascinating and threatened biodiversity.


The Search for Salamanders

On a recent exploratory trip, Claude Gascon, Conservation international’s (CI) Executive Vice President of Field Programs, and one of the world’s leading authorities on amphibians, explains the salamanders’ importance.

“These creatures are truly prehistoric,” he says. “They are from a very ancient group called Cryptobranchidae that are known to have existed for around 160 million years—way before dinosaurs walked the Earth. Giant salamanders have powerful jaws, sharp teeth and a frighteningly quick snapping reflex. There are three types left on the planet—the Japanese and Chinese giant salamanders and a much smaller American giant salamander called the hellbender [Cryptobranchus alleganiensis].”

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CI’s search for giant salamanders began at a waterfall and monkey forest in the small town of Maniwa City, amidst a magnificent countryside of steep hills with crystal-clear streams running into plunging valleys. Although the area appears to be perfect giant salamander habitat, many of the streams have been filled with concrete—a measure to prevent flooding and erosion. And small dams have been built almost everywhere.

These changes to the flow of fresh water are having a profound effect on the landscape and biodiversity of Japan, and on the giant salamanders in particular, which need rocky streams and nooks in the riverbanks to lay their eggs and raise their young.


A Legendary History

Japan’s love for amphibians, especially giant salamanders, is quite visible in Japanese culture; pictures of the salamanders can be found carved on to stones and walls. In Maniwa City there is not only a Hanzaki Shrine, but also an annual Hanzaki festival, where the townspeople parade through the streets in special costumes, doing a Hanzaki dance and pulling enormous carnival floats decorated with giant salamander sculptures 10 meters (more than 30 feet) long.

The shrine itself is a modest wooden structure that has stood in the same place for 300 years. It was built to calm the ghost of a legendary – and enormous – salamander that rampaged through the countryside killing cattle. Next to the shrine is a small Hanzaki study centre where we find several tanks containing live specimens including a gargantuan salamander, at least 1.7 meters (nearly 6 feet) long. It has colossal jaws and rolls of grey-brown skin.

Even Gascon, who as the chair of IUCN’s Amphibian Specialist Group is among the most senior amphibian scientists in the world, is left awed.

“Most salamanders could sit in the palm of your hand,” he explains. “But this one could bite your hand right off. It’s an incredible animal. I’ve never seen anything like it.”


A Roster of Threats

But this Godzilla—which is believed to be more than 150-years-old—is not cause for celebration. It is in fact an invasive Chinese giant salamander , and a serious problem for its Japanese counterparts.

Chinese salamanders were introduced as a delicacy to Japan in the 1970s by Chinese restaurateurs trying to get around a ban on eating the Japanese ones; in China, giant salamander flesh sells for $200 per pound, and as a result the species is critically endangered in its native land. But after the consumption of Chinese giant salamanders was also banned in Japan, the imported animals were released into rivers around the city.

Gascon points out: “Chinese giant salamanders have been mating with the Japanese salamanders and creating hybrids—we simply don’t know what that will mean for the future of the Japanese giant salamander population.”


Challenges and Solutions

At the Hanzaki Centre, a centre for the study of giant salamanders in the mountains of the Hyogo region, Dr. Tochimoto has spent his life studying these fascinating creatures.

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Dr. Tochimoto reiterates the impact that concreting of riverbeds, dam construction and other changes to the landscape are having on the salamanders, but also shows us the innovative solution that the Japanese government have come up with: concrete “salamander blocks” which can be placed in suitable parts of the rivers that are being concreted, and which contain holes the salamanders can wriggle through to create their breeding dens. While the salamander blocks are clearly better than nothing, Dr. Tochimoto explains that the solution only addresses one element of the changed habitat.

Captive breeding, conducted at the Asa Zoo outside Hiroshima, is proving extremely successful. The zoo is also involved in wild salamander conservation in an attempt to address threats to the species from multiple directions. In the hills outside the city, the zoo monitors a deep concrete hole with water at the bottom and an underwater tunnel leading directly into the river. There, Gascon glimpses the first wild giant salamander of our trip—the tail of a large male who has made the artificial den his own.


A Scientific Key

Finally, Gascon stops at Kyoto University, where Dr. Matsui, Japan’s leading amphibian scientist, explains an incredible link: the singular importance of the Japanese giant salamanders in protecting global biodiversity.

He explains that the chytrid fungus (Chytridiomycosis) that has been decimating amphibian populations over the last few decades, and which has contributed to the fact that at least a third of amphibian species are now threatened with extinction, has been found on Japanese salamanders for at least a century, without any ill effects.

Dr. Matsui cannot confirm whether this finding offers a path toward tackling the fungus in other amphibians, but Gascon is clearly excited. “This could be a vital tool for protecting not only Japanese giant salamanders, but amphibian species worldwide.” Though scientific research along these lines is just beginning, CI is exploring the many ways we can help move it along. And for the salamander, it certainly provides a ray of hope.

READ MORE: Why Species Matter

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