River dolphin

River dolphin, any of four species of freshwater whales found in the waters of South America and Asia, belonging to the family Platanistidae. River dolphins differ from marine dolphins in that they have longer snouts, more teeth, poorer vision, and a lower level of activity. They measure up to 9 ft (2.7 m) long, and can be black, white, yellow, pink, gray, or brown in color.