The term for a sea mammal that is often seen in aquariums is "cetacean." This classification includes whales, dolphins, and porpoises, which are known for their intelligence and social behavior. Within zoos and marine parks, dolphins are particularly popular due to their playful nature and ability to interact with humans. These mammals are adapted for life in water, possessing streamlined bodies and the ability to communicate using echolocation. Their presence in aquariums serves both educational and entertainment purposes, helping raise awareness about marine conservation and the importance of protecting their natural habitats.