There a number of fish in Minecraft, found in oceans, the mobs also has an item equivalent. Not included in this list are dolphins and turtles which are mammals, not fish.
While they count as a single mob type, they actually come in 2,700 possible combinations, which raise our total mob count below. If you want experiment with summoning different tropical fish try the apps/minecraft/tropical fish generator
How many fish mobs are there in Minecraft
4 mobs according to our database selection.