Tamer Wang Zhiyuan trains a finless porpoise named as Duoduo at the Institute of Hydrobiology under Chinese Academy of Sciences in Wuhan, central China's Hubei Province, Oct. 23, 2016. There are only around 1,000 finless porpoises, a dolphin-like freshwater mammal with iconic "grins" on the face, in the Yangtze River and two lakes that are linked to the busy waterway. (Photo/Xinhua)
