Natural History of the Lamprey Lamprey is a common name for about forty species of jawless, eel-like fishes. They are very smooth skinned and scaleless. Some can grow up to three feet in length, usually only in the oceans. All lampreys are dull colored, ranging from light-tan to molted-brown or bluish-black. Scientist consider the lamprey to be one of the least developed vertebrates. The lamprey has no bony skeleton. It only has a backbone like notochord that is made of cartilage. The lamprey only has fins at the top of it. On each side of the body is a row of seven respiratory openings through which the lamprey breathes. Adult forms of lampreys live on the b