SCIENCE LAB SCHEME : FISH REDISCOVERED

 

This ' ghost ' fish seemed extinct - but it had other ideas : The Mekong giant salmon carp is so elusive - recorded only 30 times by scientists - that they nicknamed it the '' Mekong ghost '' for the Southeast Asian river that was its habitat.

The evolutionary distinct carp species, which is not a salmon, but has a salmon like appearance, had not in fact been spotted by anyone since 2005. Researchers feared the species, which can grow to four feet long [ 1.2 meters ] and weighs 66 pounds [ 30 kilograms ], was extinct.

But one man kept looking : Chan Sokheng, who had a nearly 30-year career in the Fisheries Administration in Cambodia, and died last year.

In 2020, according to conservation colleagues he worked with, he received the call he had been hoping for : A fisherman in northern Cambodia had captured a fish with a sleek silver back, a bolt of yellow across its eye and a pronounced curved jaw. It was the Mekong ghost.

That fish was sold to traders in Vietnam, but other fishermen in the same part of the country reported their own sightings in 2022 and 2023.

Mr. Sokheng was able to collect those two animals for study, which were found farther downstream in the Mekong watershed than the salmon carp had been discovered before, according to a paper published in the Journal Biological Conservation informed by Mr. Sokheng's work that announced the species rediscovery.

Originating in China and winding through 2,700 miles [ 4,300 kilometers ] of Southeast Asia the Mekong River is the world's third most biodiverse waterway.

But like many other freshwater ecosystems, it faces threats, like upriver dams in China, Thailand and Laos as well as overfishing and pollution. [ Rachel Nuwer ]