YICHANG, Hubei, May 6 -- Artificially-bred Chinese sturgeons, a rare fish that has lived since the dinosaur age, have completed a 1,600-km migratory trip along China's longest river to the sea, scientists said on Tuesday.

Jiang Wei, a senior engineer with the Chinese Sturgeons Research Institute (CSRI), said that its scientists have monitored signals from transponders and sonar emitters implanted in the fish to trace their journey. A shoal of over 2,000 artificially-bred sturgeons were released into the Yangtze River from Yichang City on April 13.

Yichang in central China's Hubei Province is in the upper reaches of the Yangtze. It is home to the world's largest hydropower project, the Three Gorges Dam. The multi-functional water control system has been blamed for obstructing the fish's migratory route and reducing their chances of survival in the wild.

Chinese sturgeons, nicknamed "aquatic pandas", are listed as a wild creature under state protection.

Researchers with CSRI succeeded in artificially inseminating and spawning a culture of sturgeons in 2009. Since then fish have been released into the river every year to save the species from extinction. However, there are still concerns whether the artificially-bred fish can pass on the species' natural genes.

This was the first time scientists have obtained firm evidence showing that the artificially-bred fish have inherited natural migratory habits from the wild fish, and can survive in the wild.

Jiang said the school of fish released for the research were all second-generation artificially-bred sturgeons that have grown to over 70 cm long.

He said some of the fish reached Chongming Island of Shanghai, at the Yangtze's estuary, on May 3.

There are fish still in the river sections in Hubei, Jiangxi and Jiangsu provinces downstream, he said.

CSRI will continue to research the fish's migration.

Founded in 1982, CSRI is affiliated to China Three Gorges Corporation. It is the only research institution for Chinese sturgeons in the country.