Two Yangtze finless porpoises are seen surfing and frolicking in the waters near Gezhouba Dam in Yichang, Hubei Province. The Yangtze finless porpoise, famous for its playful smile and intelligence comparable to that of a 3-4-year-old child, is a small mammal native to China's Yangtze River. As a top-level protected species, it serves as a unique symbol of the river and a key indicator of its health. (Photo: pic.hubeidaily.net / Wu Chengzhong)