What is a sea animal that swims and hunts alone?

There are many sea animals that swim and hunt alone! To give you a more specific answer, I need some more information.

Could you tell me:

* What kind of sea animal are you looking for? (e.g., fish, mammal, reptile, invertebrate)

* What size are you interested in? (e.g., small, medium, large)

* Where does it live? (e.g., tropical reefs, deep ocean, open ocean)

For example, you could be thinking of:

* A shark: Many shark species are solitary hunters.

* A tuna: Tuna are powerful swimmers that hunt alone.

* A squid: Some squid species are solitary predators.

* A sea turtle: Sea turtles are typically solitary, especially when hunting.

Once I know more about what you're looking for, I can give you a more specific answer!