MEKONG GIANT CATFISH
The Mekong giant catfish (Pangasianodon gigas) it is the world’s largest catfish fish and a candidate for the world’s largest freshwater fish. Reaching three meters (10 feet) in length and weighing almost 650 pounds (295 kilograms), its lives mainly in the lower half of the Mekong River system, in Cambodia, Laos, Thailand, and Vietnam.
The Mekong giant catfish (pla buek) takes between six years and 12 years to reach full size. According to National Geographic: They "have very low-set eyes and are silvery to dark gray on top and whitish to yellow on the bottom. They are toothless herbivores who live off the plants and algae in the river. Juveniles wear the characteristic catfish “whiskers,” called barbels, but these features shrink as they age. Average life span in the wild: More than 60 years. [Source: National Geographic website]
“Highly migratory creatures, giant catfish require large stretches of river for their seasonal journeys and specific environmental conditions in their spawning and breeding areas. They are thought to rear primarily in Cambodia’s Tonle Sap lake and migrate hundreds of miles north to spawning grounds in Thailand. Dams and human encroachment, however, have severely disrupted their lifecycle.
Eleanor J. Sterling and Merry D. Camhi wrote in Natural History magazine, The Mekong giant catfish, is just one of the region’s struggling, overfished residents. With such grand proportions, a jackpot of succulent flesh that once sold at a premium to urban restaurants, the giant catfish was a fisherman’s prize catch. In the mid-twentieth century, hundreds of giant catfish---a naturally rare species---were caught each year, but recently the annual catch has declined to fewer than ten. Overfishing is the main cause of the decline, but habitat fragmentation and alteration of spawning grounds by dams and navigation projects also contribute. Today, the giant catfish is critically endangered, its range is greatly restricted, and the average size of individuals is declining. In recent years, Cambodia, Laos, and Thailand have outlawed catching the giant catfish. But the species is migratory, so a regional agreement may be necessary to prevent its demise. [Source: Eleanor J. Sterling and Merry D. Camhi, Natural History magazine, December 2007]
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Catching a Mekong Giant Catfish
In 1969, Thai fishermen near the Burmese border caught 69 giant catfish, In 1998 they caught one. In Thailand it has been several years since one has been caught. In Cambodia only about five fish are caught a year. When one is caught in Cambodia conservationist often rush to the scene and buy it from the fishermen, then weigh and tag the fish and release it. The money the fishermen get is often equal to a decades worth of pay.
The best place to catch pla buek is a stretch of the Mekong between northen Thailand and Laos near the Huay Xai, The fish is caught in April and May when river levels are low and the fish migrate to Lake Tali in Yunnan Province in China to spawn. Local fishermen sacrifice a chicken and spill its blood into the river as an offering to the river spirit who protect the catfish. The fish are caught with special nets strong enough to hold them
The pla buek is regarded as a delicacy in Thailand. The flesh is said to have a taste similar tuna and swordfish A single fish can fetch $5,000 at a market in Bangkok and ate sought after by gastronomes. Fishermen can only take 50 or 60 a year.
Fishermen Catch 293-Kilogram Mekong Catfish and Eat It
The largest freshwater fish ever recorded was a Mekong giant catfish caught in northern Thailand in 2005. It was nearly 2.7 meters (nine feet) long and weighed 293 kilograms (646 pounds). According to news reports: “Thai fishermen caught a 646-pound catfish believed to have been the world's largest freshwater fish ever recorded, a researcher said. The 8.9 foot long Mekong giant catfish was the heaviest recorded fish since Thailand started keeping records in 1981. The villagers had hoped to sell the fish to environmental groups, which planned to release it to spawn upriver, but it died before it could be handed over. The catfish was later sold in pieces to villagers to be eaten.”
Reporting from Hat Khrai, Thailand, Seth Mydans wrote in the International Herald Tribune, “The monster fish announced itself with four resounding whacks of its tail, thrashing against the net that had trapped it in the pale brown water of the Mekong River. It was a fish called the giant catfish and it was the size of a grizzly bear, taking five boatmen an hour to pull it in and 10 men to lift it when they reached the shore in this remote village in northern Thailand. It was only after their catch had been chopped into pieces and sold that they learned how special it was. At 2.7 meters, or 9 feet, long and weighing 293 kilograms, or 646 pounds, it may be the biggest freshwater fish ever recorded. [Source: Seth Mydans, International Herald Tribune, August 25, 2005]
“Before he headed out, one of the fishermen, Thirayuth Panthayom, made sure luck would be on his side. He said he prayed at the shrine to the God of Catfish and begged his boat to help him: "Please, Miss Boat, let me catch something today and I'll sacrifice a chicken for you." He had only been out for 15 minutes when, he said, he saw the fish smack the water four times with its tail - "Pung! Pung! Pung! Pung!" It took his crew an hour to pull it in. His father, as owner of the boat, earned nearly 80,000 baht, or about $2,000, for the fish from the village fishing association, a fortune in rural Thailand. Thirayuth, like each of the other four members of the crew, got 7,000 baht of this, which he said he gave right back to his father.
As part of its permit to fish for these endangered catfish, the village association then sold the fish to the Department of Fisheries, which harvests their eggs and sperm as part of a captive breeding program. After that, the fish are to be returned to the river. But, as usually happens, this fish, a female, did not survive the harvesting procedure, in which its belly is vigorously massaged and manipulated. In the end, the men of the village cut it into giant steaks and sold it. When he tried a bit, Thirayuth said, it tasted soft and sweet and mild. "It's hard to describe," he said. "You have to try it yourself."
Is the Mekong Catfish, the World’s Largest Freshwater Fish?
According to the Guinness Book of Records, the largest specimen freshwater fish ever caught was a pla buk netted in the River Ba Mee Noi, a tributary of the Mekong. The monster was reportedly 9 feet and 10¼ inches long and weighed 242 kilograms (533½ pounds). There have also been reports of fish larger than 295 kilograms (650 pounds).
Seth Mydans wrote in the International Herald Tribune, “In one of the world's more surprising mysteries, nobody really knows which is the biggest species of fish lurking in the waters of the Mekong or the Amazon or the Yangtze or the Congo or the Colorado or Lake Baikal. When the giant catfish was caught in May 2005 [near Hat Khrai, Thailand] ,Zeb Hogan, a biologist, rushed here from an expedition in Mongolia to take a look. It was his first trophy in a project to identify and study the world's largest freshwater fish in the hope of protecting their habitats and slowing their extinction. “[Source: Seth Mydans, International Herald Tribune, August 25, 2005]
Sponsored by the National Geographic Society and the World Wildlife Fund, Hogan has embarked on an 18-month expedition that will take him to five continents and more than a dozen rivers. Some species may already be too rare to study, but he has started with the Mekong, which he said had seven species of huge fish, more than any other river, along with at least 750 other species. The Mekong giant catfish may be the first to disappear from the river, he said. The few that remain can be spotted now only in central Cambodia and here, just below the Golden Triangle, where northern Thailand, Laos and Myanmar meet.
So far, Hogan said, no one has made a credible claim to top this year's trophy. It is five times the size of the biggest catfish recorded in the United States, a 121-pound Mississippi River fish that was also caught in May. "I keep expecting people to send me photos or records of larger fish, but nobody has," he said. The candidate species must grow to at least 200 pounds or longer than 6 feet - fish like sturgeon, lungfish, gars, stingrays, carp, salmon, perch and paddlefish.
Already Hogan has a collection of unconfirmed fish stories - 3-meter catfish in Bulgaria, 500-kilogram stingrays in Southeast Asia and 5-meter arapaima in the Amazon, none of them well documented. "A lot of people say the arapaima is the largest freshwater fish, but when you look at the records, there's no reliable record of any over 200 kilograms, and certainly not over 300 kilograms," he said. Hogan has his own personal candidates, the Chinese paddlefish in the Yangtze and the giant stingray here in the Mekong.
Endangered Mekong Giant Catfish
The Mekong giant catfish is considered among the world's most threatened catfish species due to dam construction and habitat degradation along the Mekong river. The fish has been disappearing fast, from more than 60 a year caught in northern Thailand in the early 1990s to just a few today. According to National Geographic only 11 and eight fish were caught in 2001 and 2002 respectively. In 2003, fishermen captured six giant catfish in Cambodia, all of which were released as part of the Mekong Fish Conservation Project
According to National Geographic: “The world’s largest scaleless freshwater fish lives a tenuous existence in the murky brown waters of Southeast Asia’s Mekong River. Once plentiful throughout the Mekong basin, population numbers have dropped by some 95 percent over the past century, and this critically endangered behemoth now teeters on the brink of extinction. Overfishing is the primary culprit in the giant catfish’s decline, but damming of Mekong tributaries, destruction of spawning and breeding grounds, and siltation have taken a huge toll. Some experts think there may only be a few hundred adults left. [Source: National Geographic website]
Seth Mydans wrote in the International Herald Tribune, “Their decline coincides with the completion of the first of a series of dams being built upriver in southern China. Many fish cue their migrations to the rise and fall of the water, Hogan said. The giant catfish are caught in April and May when they swim upriver to spawn just north of here. "The damming and the blasting of rapids have changed the habitat and the river flow," Boonluen Chinarath, the village chief in Hat Khrai, told the New York Times. He had caught as many as 100 giant catfish in nearly a half-century of fishing. "The river rises and falls more quickly than before," he said. "Maybe it's up today and maybe it's down tomorrow." [Source: Seth Mydans, International Herald Tribune, August 25, 2005]
Mekong Giant Catfish Conservation
International efforts are under way to save the species. Authorities in Laos and Thailand now limit total catches to four a year. In Thailand, a group of fishermen pledged to stop catching giant catfish to honor the king’s 60th year on the throne. However, enforcement of fishing restrictions in many isolated villages along the Mekong is nearly impossible, and illicit and bycatch takings continue. [Source: National Geographic website]
Between 2000 and the 2025, Cambodia's Fisheries Administration (CFA) and researchers have tagged and released around 100 giant catfish. The organization also runs a conservation program that encourages fishermen to report catches of rare species and release them. Conservationists said the recent giant catfish catches mark "a new era of conservation" and "new hope for the survival of a species that has become increasingly rare in much of its native habitat". [Source: AFP, December 13, 2024]
Aniruddha Ghosal of Associated Press wrote: Much is still unknown about the giant fish, but over the past two decades a joint conservation program by the Wonders of the Mekong and the Cambodian Fisheries Administration has caught, tagged and released around 100 of them, gaining insights into how the catfish migrate, where they live and the health of the species.“This information is used to establish migration corridors and protect habitats to try to help these fish survive in the future,” said Hogan. [Source: Aniruddha Ghosal, Associated Press, December 13, 2024]
In 2005, four giant catfish were released into the Mekong River after seven years of captivity Calling the rare fish "an omen of luck and prosperity," their owner, Ing Vannath, said he wanted to repay that good fortune "by returning them to their natural habitat to allow them the chance to swim freely," according to a statement from the World Wildlife Fund. Associated Press reported: The four adult fish weighed between 99 pounds and 110 pounds each and measured about nearly five feet long. [Source: Associated Press, June 15, 2005]
Ing Vannath said he bought 13 baby catfish from a fisherman in 1997, unaware they were an endangered species. Seven died in his pond and he donated two to a Buddhist pagoda. He handed the remaining four to the World Wildlife Fund in 2004 "I decided to hand over the fish to WWF because I thought they will die if I keep raising them by myself," Ing Vannath said as conservationists released the fish into the Mekong and one of its tributaries, the Tonle Sap, in the capital of Phnom Penh. Concerned that the fish may have trouble adapting to life in their natural habitat, the WWF fitted them with tags to warn fishermen they must be released back into the river. "Subsequent capture and release may demonstrate that the fish have not only been able to survive but have also managed to retain their instinct to migrate to reproduce," said WWF Director-General Claude Martin. There is no penalty in Cambodian law for keeping the fish in captivity.
Mekong Giant Catfish and the People of the Mekong Region
Aniruddha Ghosal of Associated Press wrote: The Mekong giant catfish is woven into the region’s cultural fabric, depicted in 3,000-year-old cave paintings, revered in folklore and considered a symbol of the river, whose fisheries feed millions and are valued at $10 billion annually. Local communities play a crucial role in conservation. Fishermen now know about the importance of reporting accidental catches of rare and endangered species to officials, enabling researchers to reach places where fish have been captured and measure and tag them before releasing them. "Their cooperation is essential for our research and conservation efforts,” Heng Kong, director of Cambodia’s Inland Fisheries Research and Development Institute, said in a statement. [Source: Aniruddha Ghosal, Associated Press, December 13, 2024]
Harmony Patricio told mongabay.com: The Mekong giant catfish has a lot of cultural importance for the local people. There is a lot of tradition surrounding how the fish is harvested in the wild. Now the wild population of giant catfish has gotten so low that most countries have made it illegal to catch a giant catfish in the river. I've talked to older fishers in villages that historically harvested the giant catfish, and it's really a sad thing for them that their children aren't going to experience that part of their culture. It was a very communal experience with a lot of ceremony involved. [Source: Jeremy Hance, mongabay.com, April 23, 2013 |~|]
“In some places, the whole community would get together for ceremonies and prayers. You need a lot of people to catch this fish; it's really big and heavy! After a successful harvest of a big fish, people would often share the meat and have a big ceremony and celebration. This really important cultural tradition has disappeared now.” |~|
Six Mekong Giant Catfish Found in Cambodia in 2024
In December 2024, conservationists in Cambodia celebrated the discovery of six large Mekong giant catfish. Smiling Fishermen had the picture taken alongside officials from Cambodia's Fisheries Administration (CFA) as they held up the two-meter-long creatures — weighing up to 130 kilograms (287 pounds) each — before releasing them back into their river habitat.[Source: AFP, December 13, 2024]
The six giant fish were caught and released within a five day period. Associated Press reported: The first two were on the Tonle Sap river, a tributary of the Mekong not far from Cambodian capital Phnom Penh. They were given identification tags and released. Later, fishermen caught four more giant catfish including two longer than 2 meters (6.5 feet) that weighed 120 kilograms and 131 kilograms (264 pounds and 288 pounds), respectively. The captured fish were apparently migrating from their floodplain habitats near Cambodia's Tonle Sap Lake northward along the Mekong River, likely to spawning grounds in northern Cambodia, Laos or Thailand. [Source: Aniruddha Ghosal, Associated Press, December 13, 2024]
"It’s a hopeful sign that the species is not in imminent, like in the next few years, risk of extinction, which gives conservation activities time to be implemented and to continue to bend the curve away from decline and toward recovery,” said Dr. Zeb Hogan, a University of Nevada Reno research biologist who leads the U.S. Agency for International Development-funded Wonders of the Mekong project.
That four of these fish were caught and tagged in a single day is likely the “big fish story of the century for the Mekong”, said Brian Eyler, director of the Washington-based Stimson Center’s Southeast Asia Program. He said that seeing them confirms that the annual fish migration was still robust despite all the pressures facing the environment along the Mekong. “Hopefully what happened this week will show the Mekong countries and the world that the Mekong’s mighty fish population is uniquely special and needs to be conserved,” he said.
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Last updated February 2025