The capture was part of a plan to trap up to 28 of the rare fish in an effort to study how the 25-billion dollar dam, the world's largest hydro-electric project, will affect the sturgeon's survival, the China Daily reported.

On Thursday, researchers took eggs from the captured fish and plan to artificially propagate the species, it said.

The three captured fish each weigh between 280 and 340 kilograms (616 and 748 pounds).

Pictures showed scientists measuring one of the fish which appeared to be up to four meters (13 feet) long.

The three fish were captured near the Gezhouba Dam, down river from the Three Gorges Dam and near the city of Yichang, Hubei province.

The Yangtze River sturgeon has existed for nearly 140 million years and is one of the world's most ancient species.

The fish is known to migrate some 3,500 kilometers (2,100 miles) along the river to the sea where it matures.

TERRA.WIRE