Which fish does not float?

This is a bit of a trick question! All fish float, otherwise, they would sink to the bottom of the ocean or lake.

Fish float using a variety of mechanisms, including:

* Swim bladder: This is a gas-filled sac that helps fish control their buoyancy.

* Body shape: Fish are often streamlined, which reduces drag and allows them to float more easily.

* Fins: Fins help fish to maneuver and stabilize themselves in the water, which also contributes to their ability to float.

Let me know if you'd like to know more about how fish float!