Photograph courtesy Zeb Hogan

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A boy poses with a giant barb on the Tonle Sap River near Phnom Penh, Cambodia. The fish, landed as bycatch by a local fishing operation, was tagged and released as part of a study of large freshwater species in the Mekong River Basin.

Photograph courtesy Zeb Hogan


Giant barb

The giant barb, also known as the Siamese carp, has a storied history in its native Southeast Asia. In Cambodia, it appears in ancient temple carvings at Angkor and has been named the national fish. Found in the Mekong, Chao Phraya, and Maeklong river basins, giant barbs often frequent deep pools along the river’s edge, but they can also move seasonally into canals or floodplains in search of food.

Appearance and diet

Known to reach 660 pounds, it’s the largest carp species in the world, earning it the nickname “king of fish” in Southeast Asia. With a massive head and thick, blubbery lips, the giant barb has scales almost the size of a human palm.

Slow-moving and almost exclusively vegetarian, these giant fish feed on phytoplankton, as well as algae, seaweed, and fruits of submerged terrestrial plants.


The giant barb was once an important food fish, with its meat popular to eat and pickle among people in Cambodia, Thailand, and Laos. In the late 20th century, however, its numbers dropped dramatically, mainly due to overfishing. It’s considered critically endangered, and scientists fear that populations have declined to the point where few giant barbs survive to reach the age of reproduction.

While the species is protected in Cambodia and Vietnam, illegal fishing of the species still continues, with the fish sought after by Vietnamese restaurants. A very large catch may sell for as much as $10,000, though some fishers are reluctant to target the giant barb because of its cultural and religious significance.


With wild barb numbers declining, governments in the region have focused on captive breeding in an attempt to save the iconic fish. Young giant barbs can relatively easily become acclimated to pond life, making the species suitable for farming, and more of them are now believed to live in captivity than in the wild. The maximum weight of the species in captivity, however, seldom exceeds 20 pounds.

The giant barb has also become a popular target of sport anglers, especially from Europe where carp fishing is common, and several artificial lakes in Southeast Asia stock giant barb for sport fishing.