(See Fish Gallery Below) Lamprey are primitive eel-like fishes that lack jaws, scales, paired fins, and bone (the skeleton is composed of cartilage). Nineteen species of lamprey are found in freshwater streams and lakes in North America, most along the Atlantic and Pacific Coasts and in the Mississippi River system. Six species are found in Virginia. Lamprey are river spawning fish that swim upstream to lay eggs (spawn) in nests that they excavate by removing stones to create a pit in the stream bottom. The young hatch into blind larvae called ammocetes which burrow into stream mud and remain for 3-8 years, feeding by filtering organisms from the water. Eventually they metamorphose to the parasitic adult form with rasping teeth, suctorial mouth, and eyes. Some species do not feed as adults (are non-parasitic) and spawn after metamorphosis. Most species do not have a strong effect on host populations, but sea lamprey nearly exterminated the lake trout and whitefish from the Great Lakes.