Three finless porpoises swim 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)
