What fish have gills or lungs?

This is a tricky question because it depends on how we define "lungs."

* Fish with gills: All fish have gills, which are the primary organs for breathing underwater. Gills extract oxygen from the water and release carbon dioxide.

* Fish with "lungs" (actually swim bladders): Some fish have a modified swim bladder called a lung, which allows them to breathe air. These fish are called lungfish. Lungfish are a very ancient group, and they represent a transition from aquatic to terrestrial life. They live in environments where water levels can fluctuate, and they can use their lung to survive when the water dries up.

* Fish with lungs (true lungs): Technically, no fish have true lungs like land animals. Lungs evolved from swim bladders, and fish like lungfish have only one lung.

Here's a summary:

* All fish have gills.

* Lungfish have modified swim bladders that function as lungs.

* No fish have true lungs like land animals.

So, while lungfish have lungs, they are not the same as the lungs of land animals.