The tally resulted from a project on human, ecosystem and reasonable use of natural resources in the Mekong River and Chao Phraya basin region, funded by NEF.

Among 540 fish species found in the Mekong River basin, 67 species were discovered living there for the first time, while 21 other species had never been seen previously.

The species are divided into three kinds including giant fish species, tiny species and popular species. Of these, the giant fish species are facing the risk of extinction.

According to NEF, from the end of 2007 to 2010, the project was launched and carried out in four Mekong River Commission member countries, namely Thailand, Laos, Cambodia and Vietnam to protect the giant fish species from the risk of extinction.