Pink dolphins can be found in pink, light gray or brown colors but we don't really know why they are pink.  It could be an adaptation to living in a river, or could be because their blood capillaries are near the surface of the skin. Additionally, pink dolphins get pinker when they are excited or surprised, just like how humans blush.

The Amazon River dolphin is between six and eight feet long, and weighs between 185 and 355 pounds when it is fully grown.

River dolphins are typically smaller than sea dolphins but they have longer snouts, which is how they are able to hunt at the bottom of the river. River dolphins also tend to have more pointy teeth than sea dolphins.

Most species of river dolphins are almost blind, due to navigating muddy waters, but their brains are extremely large and well developed.

Unlike sea dolphins, river dolphins have what resembles fingers on the ends of their flippers, and their dorsal fins are much smaller than that of sea dolphins or even have humpbacks instead of dorsal fins like the pink river dolphin.