Parasitic fish are a type of fish that feed off of other fish by attaching themselves to them and sucking out their bodily fluids. The most common example of this type of fish is the LAMPREY, which has seven letters in its name. Lampreys are eel-like creatures that have a round, disk-shaped mouth with sharp teeth that they use to attach themselves to other fish. They are found in both fresh and saltwater habitats and can be found in many parts of the world.