Permanent grin

The freshwater porpoise with no dorsal fin is native to China. They only live in the central and eastern parts of the 6,300-kilometer Yangtze－including Dongting and Poyang lakes－according to conservationists.

With its mouth fixed in a permanent grin, the rotund finless porpoise is adored in China as a "smiling angel". But after living in the waters for some 25 million years, the species is now fighting for its very survival.

The riverbank of the Yangtze used to be studded with steel mills and petrochemical factories that took advantage of cheap water transport, causing its water quality to deteriorate.

"Unsustainable fishing, which reduced its natural prey, collisions with ships and water pollution have all had an impact on the porpoise's health, making it critically endangered," Jiang said.

The extinction of the baiji stung the collective conscience of the Chinese people.

"We cannot afford to let the 'smiling angel' go extinct," Jiang said. "Its fate foreshadows the health of the whole river ecosystem. So the crisis is also our own."

The finless porpoise requires healthy river ecosystems, and so do the millions of people who live in the Yangtze River basin. Protecting the creature will also help alleviate China's food and water security issues, said Karin Krchnak, director of the World Wildlife Fund's freshwater program.

"Fortunately, people have awakened and are racing to save them," Jiang said.