Lampreys
There are 3 forms of these secretive creatures,river and brook with the largest being the sea lamprey. Lampreys live in coastal and freshwater in temperate regions. Eel-like, scaleless animals, they are 6 – 40 in. (15 – 100 cm) long. Lampreys have well-developed eyes, a single nostril on top of the head, a cartilaginous skeleton, and a sucking mouth with horny teeth surrounding the round opening. They spend years as burrowing larvae; adults of most species move into the sea. They attach to fish with their mouth and feed on their host's blood and tissues.
Most adult lampreys are parasitic, sucking the blood of other fishes. The horny teeth, set in the circular, jawless mouth, attach to the prey and the lamprey feeds as it is carried along. Lampreys have an anticoagulant in the saliva that keeps the blood of the victim fluid. Some freshwater lampreys eat flesh as well as blood.
Lampreys resemble eels in external appearance and, although not related to the true eels, are sometimes called lamprey eels. When not attached to prey, they swim with undulating movements. The marine lampreys normally migrate into freshwater to spawn, and some populations have become landlocked in freshwater.
