The sea lamprey is one of the most primitive freshwater fishes existing in New York. This fish, because of its eel-like shape, is sometimes called a lamprey eel, but it is not an eel at all.
Lampreys have no jaws, and their skeleton is cartilaginous.
The sea-run form of the lamprey is found regularly and extensively in the Hudson, Delaware, and lower St. Lawrence rivers. It also occurs on the periphery of Long Island. Inland, it is present in Lake Ontario, Lake Champlain, Oneida Lake, Cayuga Lake, and Seneca Lake. A key characteristic of this fish is its round, suckerlike mouth, lined with concentric rings of teeth. Its tongue also has raspy teeth.