A Fish Once Thought Extinct, the ‘Mekong Ghost’ Is Rediscovered

A giant salmon carp found in 2022.

A giant salmon carp found in 2022. Wonders of the Mekong

Recent sightings of the “Mekong ghost” fish in Cambodia offer hope for a creature once presumed extinct.

The giant salmon carp, so named because it resembles a large salmon, had not been documented by science since 2005. But scientists have now confirmed that three fish caught between 2020 and 2023 in the Mekong and Sesan rivers are members of this elusive species.

Giant salmon carp can measure up to 4 feet long and weigh more than 60 pounds, making them a type of “megafish.” The carp are in good company in the Mekong basin, which is home to some of the largest freshwater fish on the planet, including the giant catfish and giant freshwater stingray. Such creatures have been victims of excessive fishing, pollution, and the construction of massive dams.

In the new study, published in Biological Conservation, scientists call for scanning river waters for giant salmon carp DNA and for working with local fishers to track its potential whereabouts — first steps, they say, toward protecting the imperiled species.

Study coauthor Heng Kong, director of the Inland Fisheries Research Institute in Cambodia, said, “Species like the giant salmon carp are irreplaceable, and without concerted action, they could disappear forever.”

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