Five artificially-bred Chinese sturgeons were released into Yangtze River Tuesday to increase wild stocks of the rare species.

The fish were second-generation artificially-bred sturgeons, said Guo Baifu, director of species protection department at the Chinese Sturgeon Research Institute (CSRI).

"This is the first time second-filial-generation sturgeons have been released into the wild, which means we don't have to catch wild ones for breeding," Guo said.

The CSRI would use chips and other techniques to track the sturgeons for further research.

The release would help gather information on the habitat of the species, and serve as a pilot for more releases, said Guo.

Believed to have lived at the same time as dinosaurs, the Chinese sturgeon, or "acipenser sinensis," has existed for more than 140 million years.

It is one of China's most endangered species, but lingering Yangtze River pollution and disruption from shipping have hindered conservation efforts.

The CSRI, founded in 1982, has released more than 5 million Chinese sturgeons to the wild.

(Xinhua News Agency June 23, 2010)