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Today on Animal Fact Files we’re discussing river dolphins. Also known as freshwater dolphins, river dolphins can be found in Asia, South America, and arguably Africa. However, these groups aren’t closely related. An Amazon river dolphin is more closely related to an oceanic dolphin than to a Ganges river dolphin. Though they look similar with their rotund bodies, flexible bodies and their long snouts, this is an example of convergent evolution which is when two distantly related species display similar characteristics.

Like oceanic dolphins, river dolphins are mammals. They give birth to live young which they nourish with milk. River dolphins have smaller eyes than their marine counterparts. They live in murky water and don’t depend on their eyes for hunting. River dolphins also lack a distinct dorsal fin when compared to many oceanic dolphins. Oceanic dolphins tend to travel in groups called pods while river dolphins may live in smaller groups or even on their own.

River dolphins have long beaks that can reach four times the length of an oceanic dolphin’s nose. Plus, river dolphins are more flexible than their ocean dwelling relatives. Oceanic dolphins are built for stronger swimming while river dolphins aren’t as active and seek out their prey along the bottom of freshwater systems. Prey to river dolphins includes freshwater fish and crustaceans. In turn, their young may be taken by large predators like caimans, jaguars, or anacondas, however, the biggest threat to river dolphins are humans.

Depending on who you ask, there are six living species of river dolphin. In South America, there is the iconic Amazon River dolphin, also known as the pink dolphin for its coloration! There may be two other species who look pink, though it’s currently debated if these should be considered separate species from the Amazon River dolphin. Next is the franciscana, a dolphin that lives in coastal waters as well as rivers. This dolphin has a more pronounced dorsal fin but also sports the long beak seen in fully freshwater dolphins. Another contender is the tucuxi, a freshwater dolphin that looks more like an oceanic dolphin and can enter saltwater but prefers not to.

Moving away from South America, while there may not be true river dolphins in Africa, it’s worth mentioning that the Atlantic humpbacked dolphin lives along the coast of west Africa and spends some of its time in freshwater rivers. Finally, in Asia, there are the Ganges River dolphin and the Indus River dolphin, though some sources don’t classify these as separate species. The Chinese river dolphin may also be listed, but the species is considered functionally extinct as of 2006. All river dolphin species are threatened with extinction. They face water pollution, run ins with boats and fishing gear, habitat destruction, and population separation due to dams. Without conservation efforts, all river dolphins face the same fate as the Chinese river dolphin.

In size, river dolphins range from the Amazon and Ganges River dolphins at over eight feet (2.4m) long, to the franciscana at just over four feet (1.2m) long. If they can avoid threats, something that becomes more and more difficult for them each year, river dolphins can live to be decades old.

For more facts on river dolphins, check out the links below. Give a thumbs up if you learned something new today. Thank you to our Patrons SpikeSpiegel93, Dad, and everyone else for their support of this channel! Thanks to these people for today’s request! And thank you for watching Animal Fact Files!