Sea lampreys are anadromous, and migration is triggered by changes in water temperature. In general, they prefer shallow coastal areas, though they are found at depths between 0.91 and 4.57 m. Young lampreys are hatched in gravel or rock beds in small, freshwater streams and rivers. After the larval stage, they migrate into saltwater ocean habitats. They return to freshwater to lay their eggs. Sea lampreys thrive in systems where the following are present: 1) waterways lacking obstructions (like dams or waterfalls) with clean sand and gravel areas for spawning; 2) sand beds free of pollutants with a large supply of organic matter for their developing young; and 3) large waterways with a plentiful supply of fish to serve as hosts for their fully developed offspring.
Range depth: 0.91 to 4.57 m.
Habitat Regions: saltwater or marine ; freshwater
Aquatic Biomes: lakes and ponds; rivers and streams; coastal