Feared Extinct, The ‘Mekong Ghost’ Resurfaces

An adult giant salmon carp, a fish species that can grow as large as 66 pounds (30 kilograms), has been documented in the Mekong River for the first time in 18 years. Photo Chhut Chheana

One of the world’s most threatened fish species has been unexpectedly re-discovered in northern Cambodia.  No adult giant salmon carp (Aaptosyax grypus) had been officially recorded since 2004, but earlier this year a 13-pound specimen was reported from a local wet market along the Mekong River, the only river system on Earth where the species lives.

So rare is the giant salmon carp, it has been referred to as a “Mekong Ghost.” It is listed as critically endangered on the IUCN Red List of Threatened Species. Although the fish was not found alive — with the cause of death unknown — its discovery has raised hope that the species still prevails in the Mekong.

“After more than two decades of working on this topic, I’m so happy to confirm the existence of this unique animal,” said Mr. Chan Sokheng, a biologist with the Cambodian Fisheries Administration.

“This year has been a grand slam for wildlife surprises on the Mekong, but the game is far from over and victories for biodiversity are still hard to come by,” said Zeb Hogan, a University of Nevada, Reno fish biologist who leads the USAID-funded Wonders of the Mekong research project.  

The Mekong River, which runs through six Asian countries, is a global biodiversity hotspot and home to almost 1,000 different species of fish, including some of the world’s largest freshwater fishes. But the river and its many tributaries, which sustain the livelihoods of tens of millions of people, have come under increasing pressure in recent years from dam building, overfishing, and climate change, with the largest fish species at particular risk.

“The recent discoveries along the Mekong have been the result of outreach to local people, many of whom have a deep knowledge and dependence on the river and its wild creatures", said Ms. Chea Seila, Wonders of the Mekong project manager.

The salmon carp's revival was confirmed after the three-foot-long specimen appeared in the market. The merchant then contacted Sokheng and from the photos, Sokheng was able to identify it as a giant salmon carp based on its sharply curved jaw, yellow stripe on its head, and fusiform shape reminiscent of a salmon. Scientists will use the DNA of the dead fish to develop various tools for studying the distribution of the species. They also hope to find more specimens alive that can be tagged and released for further study.

“The discovery of yet another amazing, but highly endangered animal, in an area that supports the livelihoods and food security of millions of people, shows plain as day the urgent need for conservation programs and the potential benefits of government, scientists, and local communities coming together to safeguard the wonders of the Mekong,” said Hogan.

Media Contacts:

Ms. Chea Seila

Project Manager, Wonders of the Mekong

+ 855 77 555 804

[email protected]

Dr. Zeb Hogan

Project Lead, Wonders of the Mekong

+ 1 530 219 0942

[email protected]

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