Imagine boating down one of the longest rivers in the world, the Amazon River, minding your own business — calmly keeping an eye out for alarmingly large anacondas — and a curious pink dolphin appears to swim alongside. While this may seem like a mythical creature, pink dolphins do exist in the Amazon region.
The Amazon river dolphin (Inia geoffrensis), also known as a boto, is a giant among its genus. It can measure up to 8 feet (2 meters) long and weigh around 450 pounds (204 kilograms) — as much as three full kegs of beer! Size isn't the only thing that sets the Amazon river dolphin apart; this freshwater dolphin, which thrives in South American rivers and temporary lakes caused by seasonal flooding, is sometimes ... shockingly pink.
Although born gray, males of the species are easily identified as they enter adulthood by a decisive pink hue. Their unusual coloring, which is sometimes wholly pink and sometimes mottled with gray undertones, is believed to be the result of scar tissue from dolphin rumbles — whether playfighting or a serious bid for a mate. The richer the rosé, the more attractive the males are believed to be, and the older the male, the more the pink he will have.
There's also a theory that salmon-colored dolphins more readily blend in with their surroundings. During heavy rains, rivers along the Amazon rainforest turn a murky red/pink hue, and with their pink coloring, male dolphins are more easily camouflaged.
The Amazon's pink river dolphins are one of five dolphin species that live in freshwater rivers; they are distantly related to saltwater-adapted ocean dolphins. In addition to their distinctive pink color, the Amazon's pink river dolphins have another feature that sets them apart from their saltwater cousins. Unlike oceanic dolphins, which have a dorsal fin that protrudes from their backs, pink river dolphins have a hump instead.
The Amazonian wetland system, fed by the Amazon River, is a crucial place for pink dolphins to breed, and since 2018 has been granted internationally protected status. The area is home to an astounding variety of rare species. It includes hundreds of plant, bird, reptile, mammal and amphibian species that have thus far been cataloged.