What Happened to the Giant Mystery Fish of Malaysia?

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You may have missed this, but last summer, it was big news in Malaysia. Villagers who live along Kenyir lake reported that that its waters seemed to be inhabited by an immense predatory fish with a penchant for leaping high out of the water. Locals called it kan naga, after a mythical dragon, while the Star, an English-language Malaysian newspaper, dubbed it the “Kenyir Monster.”  One villager reportedly claimed that the creature was the size of a baby elephant, but others estimated its length at between 10 and 13 feet. There was even feverish speculation that the fish somehow had caused the June 2009 drowning deaths of two men–a local park supervisor who mysteriously fell out of his boat, and an emergency rescue worker who went into the water after him. Could they possibly have encountered the giant fish? And where had the giant suddenly come from? If you think that the 12,000-year-old Loch Ness is too new to harbor a prehistoric monster, then Kenyir, a manmade body of water that is just 25 years old, is an even more unlikely lair for some ancient throwback.

A Malaysian marine biologist, Mohd Fadzil Suhaimi Ramli, subsequently came up with a more plausible theory. The Kenyir Monster seemed to fit the description of  Arapaima gigas,  a predatory fish native to the Amazon basin in South America. Also known as the giant Arapaima, the paiche and the pirarucu, A. gigas, which has a wide, scaly gray body and a tapered head is one of the biggest, feistiest freshwater fish around. A 2003 reference book, Check List of the Freshwater Fishes of South and Central America, says that longest documented specimen was nearly 13 feet in length, and that there have been unverified reports of up to 15 feet. As the National Geographic profile of the fish notes:

Though arapaimas can stay underwater for 10 to 20 minutes, they tend to remain near the water’s surface, where they hunt and emerge often to breathe with a distinctive coughing noise. They survive mainly on fish but are known to occasionally grab birds close to the water’s surface.

That would explain the surface sightings.  Yes, and it’s also an impressive leaper. But how did it get roughly 10,000 miles from its home in the Amazon to a lake in Malaysia?

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One possible explanation: Somebody had obtained the fish from South American and, for reasons unknown, had put it in the Malaysian lake. The Star reported a bizarre secondhand anecdote:

Another villager Mohd Fahmi Mustafa, 25, said his grandfather told him that an old Chinese man appeared one day at the village in the late 70s and released two fish that resembled a dragon into the then Kenyir river.

“My grandpa said the old man had claimed that the fish were from overseas and that he had to release them as they had become too big,” he said.

That actually isn’t as strange of a scenario as it might seem. After all, according to this Straits Times article, 120 of the 382 species of freshwater fish found in Malaysia are non-indigenous species that started out as escaped farm fish or pets:

Some were released into the water system by fish enthusiasts who at some time or other had to give up their hobby. These fishes adapted and thrived in the healthy ecosystem and began breeding. Fortunately, few of these are actually harmful to the ecosystem although some of the more predatory species such as the South American Peacock Bass are frowned upon by the authorities as there is fear that it might deplete some of the valuable indigenous species and cause an inbalance in the ecosystem.

Peacock bass are one thing, but the idea that an invasive Amazonian eating machine the size of a small boat—and possibly even more than one of the creatures–was on the loose in Kenyir lake, presumably gobbling up local species, gave Malaysian fisheries officials cause for alarm. And the possibility—however remote—that the fish had caused two fatalities was not something they could afford to ignore, either, since the government has been trying to develop the lake as a tourism attraction. In July, according to this press release from the official Malaysian government news agency, fisheries officials offered a reward of 10,000 ringgits—about $3,100—for anyone who could capture the  monster.

Menteri Besar Datuk Ahmad Said said the state would allow catching of the giant fish at the lake from today until August 15, except in areas gazetted as part of Taman Negara and the Kelah Sanctuary.

“We hope the Giant Arapaimas would be caught alive because we plan to send them to the Mini Zoo and Recreation Park in Bukit Takal, Kemaman, so that it can become of the area’s main attraction,” he said here today.

According to a subsequent Star article, the bounty attracted scores of sport fishermen from as far away as Europe—probably not so much because of the money but the novelty, since A. gigas has been overfished to the brink of extinction in the Amazon, and big specimens are seldom seen anymore there.  (One reason the fish is a prized catch, according to its National Geographic profile: The arapaima has an unusual “bony” tongue fitted with a set of teeth, which some indigenous people use as a scraping tool.)

Apparently, however, the sport fishermen all came away empty-handed, because the April 15 deadline came and went without any announcement of a capture. And there haven’t been any sightings of the Kenyir Monster reported, either by the Malaysian news media or by the Malaysian Forest Explorers blog, which tracks local nature happenings.  So what happened to the giant fish? Is it still alive? If there are any Malaysian readers who know anything about it, please contact us. Inquiring minds want to know.
Btw, if you’re interested in huge freshwater fish, National Geographic grantee explorer Zeb Hogan, an aquatic zoologist, is leading the Megafishes Project, which aims to identify, document and help protect the world’s largest freshwater fishes, ranging from the Mekong giant catfish to the giant freshwater stingray. We’ll be writing more about this effort in the future.


  1. jimmyboy171
    June 30, 2010, 9:58 am

    how do they taste???anyone knows!!!

  2. Oleg Musin
    July 23, 2013, 8:29 pm

    I work in Malaysia as a lecturer of physics and have a lot of free time which I’m using for fishing – my very hobby. If somebody interested in description and exploring of Malaysian freshwater fish species you could contact me oleg.y.musin@gmail.com

  3. New Arapaima Species Described
    October 17, 2013, 2:45 pm

    […] National Geographic: Mystery Fish of Malaysia […]

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  5. DEHR thierry
    December 7, 2014, 1:43 pm

    Married to a Malaysian, I have been fishing in Kenyir dam as well as Temmengor for more than 20 years (Including many of the upper rivers which flow into them)
    I know practically every corner of those dendritic lakes.
    I am mainly a giant snake head (toman), kelah and sebarau fisherman.
    Also never recorded (I never wanted to register it to avoid swarm of fisherman on the spot)
    I probably hold the world record with a 21 kg snake head and a few 13kg taken about 15 years ago (the 2013 IGFA record stand at 11.79kg. )
    Regarding the Monster fish which made news in Malaysia recently, I give you a scoop, I can assure you that this fish do exist not only in Kenyir but in Temmengor as well.
    There are some shapes which are unmistakable for any fisherman. The arapaima is one of them. At the moment it leaps out of water you know what you have seen.
    This has occurs 4 times to me. Once in Temmengor and 3 times in kenyir.
    The first time it happened was about 15 or 18 years ago. I was sitting in my boat waiting to spot a Snake head coming to surface when I saw a huge fish leaping high out of the water just under a dead tree. At the moment it leaps out, a bird flew from the branch.
    This first time was a bit far for me to confirm it was an arapaima, but this same scenario repeated few years later. This time I could clearly see the shape, and within a second I said “arapaima”
    It was leaping at birds!!!
    I have never heard anybody catching one of them in Kenyir or Temmengor, but local aborigines have told me about huge fish roaming the lakes.
    I have noticed a strong decline on giant snake head over the years. And I would rather think that commercial fishing which started on the dam is the culprit.
    One thing is sure those lake have the capacity to hold some of the biggest arapaima ever recorded if no one have been able to catch them.