A 291-kilogram wounded Chinese sturgeon has been doing well after 12 days of treatment in a temporary breeding base in Shanghai, protection workers said on Sunday.

The 3.37-meter Chinese sturgeon, which was caught by fishermen in the Jinhui port in Shanghai, is recovering well from its multiple lacerations and gores, though it has not yet taken food, said a worker with the Shanghai Yangtze Estuary Chinese Sturgeon Conservation Office.

The sturgeon is now being treated in the Jiading Chinese Sturgeon Temporary Breeding Base, where workers are trying to let him enjoy a "cool summer" with air conditioners and ice as outside temperature has remained above 37 degrees Celsius in the past few days.

"Four more air conditioners will be installed at the four corners of the wounded sturgeon's swimming pool-like 'sickroom' to ensure its water temperature stands at 23 to 24 degrees Celsius," said a worker.

The Chinese sturgeon, known as a living fossil because it is one of the oldest vertebrates in the world, has existed for more than 200 million years.

Scientists with the Yangtze River Fisheries Research Institute said the number of Chinese sturgeon that migrate to the Yangtze River each year to spawn has dropped from more than 2,000 in the 1980s to just 500 now.

Since last November, 11 adult Chinese sturgeons have been found dead, most by ship propellers, and some died after being electrified by fishing nets, according to the office.