 The lamprey's classification: Order: Lamprey Family: Petromyzontidae The sea lamprey is a parasitic fish, not an eel, and is native to the northern and western Atlantic Ocean. It is one of the most primitive vertebrate species. The fish invaded the Great Lakes in the early 20th century through the St. Lawrence River and various shipping canals. Lampreys lack scales, fins, and gill covers. Like sharks, their skeletons are made of cartilage. They breathe through a distinctive row of seven pairs of tiny gill openings located behind their mouths and eyes. Sharp teeth surround a rasp-like tongue at the centre of a large sucker mouth. 
 The lamprey uses its suction-cup mouth full of sharp teeth to latch on to a fish. It then uses its rough tongue to rasp away the fish's flesh so it can feed on its fish's blood and body fluids. One lamprey kills about 40 pounds of fish every year.Lamprey live part of their lives in salt water, but have adapted to living invasively in fresh water in the Great Lakes. As adults, they spawn in rivers and streams, and their bottom-feeding larvae transform into adult parasites that migrate into lakes. Only one in seven fish attacked by sea lamprey survive. In the five Great Lakes the lamprey preys on commercially important fishes, including trout, whitefish, perch, and sturgeon. In the past fifty years the trout fishery has completely collapsed, largely due to the lamprey's unchecked spread. 
Today, the Great Lakes Fishery Commission coordinates control of sea lampreys in the lakes, which is conducted by the U.S. Fish and Wildlife Service and Fisheries and Oceans Canada. Biologists set up barriers and traps in the streams that feed the lakes, to prevent the lamprey moving upstream, and apply chemicals called lampricides that target lamprey larvae, but are harmless to other water creatures. New techniques to control sea lampreys are always being developed. For example, since lampreys use odours with pheromones to communicate, scientists have reproduced these odours to help control lamprey populations. |