A remarkable discovery has occurred in the Mekong River, where the giant salmon carp, a fish believed to be extinct, has been spotted three times in recent years.
“The giant salmon carp represents the Mekong region,” noted Chheana Chhut, a researcher affiliated with the Inland Fisheries Research and Development Institute located in Phnom Penh, Cambodia.

This predatory species can reach lengths of up to four feet and is characterized by a distinctive knob at the end of its lower jaw along with an eye-catching yellow patch around its large eyes.
Previously, the last confirmed sighting of this fish took place in 2005, leading scientists to believe that it had seemingly vanished from the Mekong for many years.
Chheana is a co-author of a recent study published in the journal Biological Conservation, which highlights these new sightings.

Since 2017, biologists engaged in tracking migratory fish species in Cambodia have formed partnerships with local fishing communities to keep an eye out for any unusual fish appearances.
Consequently, the three giant salmon carp discovered in the Mekong River and one of its tributaries in Cambodia between 2020 and 2023 were reported through these community connections.
“Witnessing the real fish for the first time was surprising and thrilling,” expressed Bunyeth Chan, a co-author of the study and researcher at Svay Rieng University in Cambodia.

The recent sightings offer renewed optimism regarding the future of this species. Known colloquially as the “ghost fish,” its rediscovery is generating excitement among researchers.
“This finding is incredibly uplifting,” stated Zeb Hogan, a fish biologist at the University of Nevada, Reno, who was involved in the team studying the fish.

However, the situation surrounding the giant salmon carp illuminates the broader challenges faced by migratory fish species in the Mekong River, which is significantly impacted by industrial pollution and overfishing.
Over 700 dams have been constructed along the river and its tributaries, and few functional fish passages are available to assist the species as they navigate these obstacles, according to Brian Eyler, who directs the Southeast Asia Program at the Stimson Center in Washington.

Researchers are optimistic that collaborating with local communities in nearby Thailand and Laos will provide them with further insights and help confirm whether the giant salmon carp still populates other areas of the Mekong River.