While they are both part of the natural world, ocean dolphins and rivers are very different and don't share many similarities.
Here's why:
* Ocean dolphins are mammals: They breathe air, give birth to live young, and nurse their babies.
* Rivers are bodies of water: They are flowing systems of freshwater.
Perhaps you were thinking of river dolphins? These are a specific type of dolphin that live in freshwater rivers like the Amazon and Ganges.
If you're interested in the similarities between river dolphins and ocean dolphins, here are some:
* Both are marine mammals: They share the same basic physical characteristics, like streamlined bodies, flippers, and blowholes.
* Both are highly intelligent: Dolphins are known for their complex communication and social interactions.
* Both are adapted to their environments: Ocean dolphins have evolved for life in the ocean, while river dolphins have adapted to the specific conditions of rivers.
Let me know if you'd like to learn more about river dolphins or any other type of animal!