The discovery of a Yangtze sturgeon in Hubei province has ignited hope that the species, which was believed to be extinct in the wild, will be able to restore its population in nature.

A large sturgeon was found in shallow water in the Yangtze, Asia's longest river, by a resident in Tuanfeng county, Hubei province, on Wednesday. Officials from the local fishery administration arrived at the site soon after they were notified.

The fish, which was some 96 centimeters in length and weighed 4 kilograms, was recognized as a Yangtze sturgeon.

In July, the International Union for Conservation of Nature and Natural Resources announced the extinction of the wild Yangtze sturgeon in its updated Red List of Threatened Species.

Tao Di, a law enforcement officer with the administration, said on Thursday that the Yangtze sturgeon was released on Wednesday afternoon after researchers had collected some samples from the fish.

"It was stranded with slight injuries when found," he said. "It had renewed vigor after being treated. We wanted to release it as soon as possible so that it can resume eating."

A species endemic to China, the Yangtze sturgeon, which is under first-class State protection, was once distributed in the upper and middle reaches of the Yangtze, said Du Hao, a researcher at the Yangtze River Fisheries Research Institute in Wuhan, the capital of Hubei. Du helped identify the fish on the basis of videos and photos.

They can live 20 to 30 years in the wild, said Du, whose team has conducted research on rare and endangered fish species in the Yangtze for a long time. Monitoring has shown that the Yangtze sturgeon had stopped its natural reproduction around the year 2000.

For years, authorities along the Yangtze have made consistent efforts to help restore the Yangtze sturgeon's wild population by releasing fry bred in captivity. In October, for example, 50,000 Yangtze sturgeons, each with a length of about 30 centimeters, were released in the Yangtze section in Yibin, Sichuan province.

In a move to help aquatic species recover, the Chinese government placed all natural waterways of the Yangtze under a 10-year fishing moratorium on Jan 1 last year.

Du estimated that the Yangtze sturgeon found in Tuanfeng was 5 to 6 years old. Du added that he was not sure whether it was bred in captivity.

"But I can tell that it has lived in the wild for a long time, and it's in healthy condition," he said, adding that it's highly possible that it will mature in two to three years. "If the number of mature Yangtze sturgeons can further grow, a new breeding area for the fish may come into being in the middle reaches of the Yangtze."