China released 120,000 endangered Chinese sturgeons into the Yangtze River on Thursday in a latest move to boost the species' flagging number in the wild.

The prehistoric sturgeons, along with 2,000 rare mullets, were set free in the river's section at Yichang City of central China's Hubei province, where the world's largest hydroelectric project, the Three Gorges Project is located.

The fish, 16 centimeters long on average, were raised in captivity by the Chinese Sturgeon Research Institute, under the China Three Gorges Project Corporation.

The institute was founded in 1982 to study the artificial propagation of the Chinese sturgeon, which is believed to be on the verge of extinction. Since then, five million such fish have been released to the Yangtze River.

Xiao Hui, chief engineer at the institute, said the fish freed Thursday were hatched in November last year and the timing of the release determined by a group of experts would maximize the fish's viability in the wild.

The institute would release more sturgeons in April, with an average length of 30 centimeters, Xiao added.

The Chinese sturgeon is known as "living fossil" because it is one of the world's oldest vertebrates -- dating back to 140 million years ago.

Less than 300 wild sturgeons are reported to live in the Yangtze River. They can reach up to five meters and weigh up to 500 kilograms.

The fish's decline has been largely due to pollution and illegal fishing. The fish usually gather at the mouth of the Yangtze River in east China and every Spring swim upstream to spawn.

(Xinhua News Agency March 13, 2009)