Sea Lamprey

The sea lamprey is a jawless fish native to the coastal waters of the North Atlantic, using a circular, tooth-lined sucking mouth to attach to other fish and feed on their blood and body fluids, a habit that has earned it the nickname vampire fish. As one of the most ancient surviving fish lineages, it lacks jaws, scales, and paired fins entirely, retaining a body plan that predates most other living fish groups. Introduced into North America's Great Lakes, it became a highly destructive invasive species that devastated native fish populations before control programs brought it partly under control.