Fish: This is the largest group of sea vertebrates. They include:
* Bony fish: Like tuna, salmon, cod, and goldfish.
* Cartilaginous fish: Like sharks, rays, and skates.
Reptiles: These include sea turtles, sea snakes, and marine iguanas.
Mammals: These are warm-blooded and breathe air. They include:
* Cetaceans: Whales, dolphins, and porpoises.
* Sirenians: Manatees and dugongs.
* Pinnipeds: Seals, sea lions, and walruses.
Birds: Some birds are adapted to life at sea. These include:
* Seabirds: Albatrosses, penguins, gulls, and puffins.
Other:
* Amphibians: There are very few amphibians that live in the sea, but some frogs and salamanders can tolerate saltwater environments.
It's important to remember that the classification of these animals is constantly being updated as new research emerges!