Boto or Amazon River Dolphins are the largest freshwater dolphins alive, growing up to nine feet long and weighing roughly 300 pounds. They are often a pink color, but can also be pale blue and frequently are albino. Because they have poor eyesight, they use the echolocation-bump on their head as a sensory detector to help find food or to protect them from danger. Some reports say that they can even scare of prey with bursts of sound from the organ in their bulging forehead. They can even make the bump change shape too, from flat to spherical.