Also known as White Fin and White-fin Dolphin, it belongs to the Platanistidae family of Cetacea order, with the Latin scientific name of Lipotes uexillifer, and the English name, Baiji, Chinese river or white-fin dolphin.     

White-fin Dolphin is a mammal similar to dolphins, living in fresh water of rivers. Its body is in the shape of spindle. The skin of the whole body is bare and hairless, with long snout. The eyes are small and degenerated. Its sonar system is especially sensitive, able to detect and identify objects in water. Its back fin is in obtuse triangle, with fin limbs and tail fin all stretching in horizontal direction. It has steel gray back and white belly. The body color of the newborn dolphin is deeper than that of the adult. By far, the largest female individual ever found is 253 centimeters in length and 237 kilograms in weight, while the largest male individual is 216 centimeters in length, and 125 kilograms in weight.  

White-fin Dolphin lives in middle and lower reaches of the Yangtze River, near areas with many shoals, side beaches, and large or small tributaries and mainstreams. It prefers living in groups generally of 2 to 6; its collective behaviors are more distinct especially in mating season in spring. It has comparatively high requirements for hydrological condition, often staying for a period at one fixed area; and when the hydrological condition changes, it moves to another area. It feeds on fishes. White-fin Dolphin breeds once in two years, and baby dolphins are born in March to August, one baby per pregnancy; at birth the body length is about 80 centimeters. The female dolphin is mature at the age of 6 (the length from head to tail is over 200 centimeters); and the male dolphin is mature at the age of 4 (the length from head to tail is about 180 centimeters).  

Endemic to China, it is limited to the middle and lower reaches of the Yangtze River. It needs urgent protection since the existing amount is only about 100 heads.