Symbolic Mekong Endemic Fish Species Rediscovered in Cambodia

The giant salmon carp (Aaptosyax grypus), a symbolic Mekong endemic fish species, has been rediscovered in Cambodia.

According to the Wonders of the Mekong project, for the last few decades, people in Cambodia have been unable to catch the elusive giant salmon carp (Aaptosyax grypus). In fact, most people thought that the species had completely disappeared from the Mekong region, especially in the Mekong River in Cambodia. However, on June 28, 2022, a six-kilogramme giant salmon carp, with a standard body length of 74cm and a total body length of 88cm, was caught by a fisherman in the upper part of the Sesan 2 hydropower reservoir.

The giant salmon carp (Aaptosyax grypus) is a unique fish species that lives primarily in deep pools in the Mekong River in central Thailand and Laos. In Cambodia, the giant salmon carp, known in Khmer as “Trey Pasanak”, lives in the upper part of the Mekong River in Kratie and Stung Treng provinces.

“The Trey Pasanak is a rare and endangered fish species that is under-researched, and its numbers are poorly recorded because it is not a target fish for fishermen. Its presence is surprising and very interesting to me,” said Dr. Chaiwut Grudpan, from the Department of Fisheries of Obun Ratchathani University, Thailand, who specialises in identifying fish in the Mekong region.

“We have not seen this fish species since about 2002. This is the first time we have encountered it. Although the Trey Pasanak is a rare species, the discovery shows that it is still present in Cambodia. This means that the Mekong or Tonle Sap is still home to endangered species, rare fish and other freshwater fish,” Mr. Thach Phanara, Head of the Laboratory Division at the Inland Fisheries Research and Development Institute and a Mekong Conservation Hero told AKP recently.

Mr. Chan Sokheng, Deputy Director of the Fisheries Technology Research Office of the Inland Fisheries Research and Development Institute of the Fisheries Administration and the author of the book “Freshwater Fish in the Kingdom of Cambodia (Characteristics and Brief Biology)” which contains information on a total of 388 species of fish, including brackish water fish species, expressed his excitement with the presence of Trey Pasanak as he has been tracking the fish species in Cambodia for 30 years. “I look forward to working with the Wonders of the Mekong project to conduct research that informs effective conservation of this endangered species,” he said.

In Cambodia, the giant salmon carp, or Trey Pasanak, is found in the upper Mekong River. Because it is very rare, most Cambodians have never seen or heard about the fish species. Trey Pasanaks can grow very large, up to a maximum standard body length of 130 cm and a maximum weight of 30 kg. The fish has scales covering its elongated body, and a peculiar knob on its lower jaw. The giant salmon carp is a fast-swimming predator that feeds on other fishes. The giant salmon carp is classified as “Critically Endangered” on the IUCN Red List of Threatened Species.

Source: Agency Kampuchea Press