Look into the waters of some of the world's biggest rivers, and you might see a strange sight-dolphins. These aren't the same type of dolphins that swim in the ocean, but they do share some similarities. River dolphins have long beaks lined with teeth that stab into prey, and they show intelligence when hunting by swimming in clever positions. These creatures live at a slower pace than saltwater dolphins, usually swimming just one mile per hour.
Beak Full: Most river dolphins have extra-long beaks that hold from 100 to 230 sharp teeth. The creatures clamp these jaws around fish, impaling victims to make quick kills.
Changeup: The Amazon river dolphin can actually change the color of its skin. The aquatic mammal is dark when relaxed, but lightens to a pinkish color when excited and moving quickly as blood flows faster near the surface of its skin.
Smarties[]
River dolphins find prey on river bottoms by stirring up sand with their tails.
Like dolphins that live out at sea, river dolphins have also come up with some smart ways to hunt their prey. Many species have wide cheeks that prevent them from seeing what's directly beneath them in the water, so they swim on their side and even upside down when looking for a meal. Indus and Ganges river dolphins in India are even known to drag their tails through the river bottom to uncover freshwater crabs and other crustaceans that burrow into the mud.
Not Good Looking: River dolphins have small eyes and poor eyesight. One species, the Ganges river dolphin, lacks lenses on its eyes and is completely blind. Like oceanic dolphins and bats, the animals navigate and hunt by echolocation.
Take it Easy: Unlike their saltwater cousins, most river dolphins are slow movers. They normally cruise through the river at one mile per hour, but can swim at six miles per hour for short distances when necessary.
Distant Cousins[]
Scientists have found fossils of ancient river dolphins that date back as far as 24 million years ago. The ancient species look much like modern river dolphins, and are even classified in the same family. Scientists believe that river dolphins and oceanic dolphins evolved from common ancestors, but the modern animals are not closely related to each other.
Trading Card[]
Trivia[]
- The knowledge card says River Dolphins. The trading card says River Dolphin.
- The species mentioned on the card are the Amazon river dolphin (Inia geoffrensis), the Ganges river dolphin (Platanista gangetica gangetica), and the Indus river dolphin (Platanista minor). It is hard to tell which of the three, if any, is used in the featured illustration.
- While not having its own card in the series, the aforementioned Amazon river dolphin is used on the Bottlenose Dolphin card's Creature Comparison in Wildlife Explorer.
- The river dolphin is the only modern freshwater cetacean featured in the series, and one of two modern cetaceans not in Monsters of the Deep, alongside the Bottlenose Dolphin.
- Counting the Ambulocetus, it is one of two freshwater cetaceans.
- While not explicitly named on the Weird n' Wild card itself, the Wildlife Explorer card confirms the corpse on the King Vulture's knowledge card is a river dolphin.
- The river dolphin is featured in It's All Relative! on Monster Mania 98.