If grey area is
not all filled in to show entire puzzle... center the
puzzle in your screen, then hit your browser's RELOAD.
Return to Education homepage
Return to the Columbia River Fisheries Program homepage
Three lamprey species including the Pacific lamprey (Lampetra tridentata), western brook lamprey (L. richardsoni), and river lamprey (L. ayresi) are found in the Columbia River Basin. Lampreys are an ecologically, economically, and culturally valuable species. Pacific lamprey populations in the Columbia River Basin have declined and the status of western brook and river lampreys is unknown.
The Pacific lamprey ranges from southern California to Alaska. They are found in Washington, Oregon, Idaho, California, Alaska, and British Columbia. They were once abundant in streams in the Columbia River but their distribution has been significantly reduced.
The Pacific lamprey is a very primitive, eel-like fish. The Pacific lamprey lives in the ocean as adults where they feed on the blood and bodily fluids of marine mammals and fish. Pacific lampreys are anadromous, meaning that they live in both fresh and salt water. After about two years in the ocean, the Pacific lamprey return to fresh water streams to spawn. Upon entering freshwater the adult lampreys stop feeding and spawn or over-winter and spawn the following spring. Lampreys construct nests in small gravel where they lay their eggs. Like salmon, lamprey die soon after spawning. Eggs hatch after several weeks and the blind larvae are called ammocoetes. Ammocoetes live in fine sediment filter feeding algae and detritus. After 4 to 6 years as an ammocoete, Pacific lampreys metamorphose to a second juvenile life stage called macropthalmia. The macropthalmia stage migrates out to the ocean and begins a parasitic lifestyle as an adult growing to about 2 feet in length.
The lamprey were once an integral part of the Columbia and Snake River tribal cultures. They were harvested for subsistence, ceremonial, and medicinal purposes. Today, lamprey are used for scientific research, educational purposes, vitamin oil, and anti-cooagulants. Their spawned out carcasses provide a source of nutrients to the freshwater streams.
Pacific lamprey are vulnerable to many of the same threats that have reduced salmon populations. These threats include poor habitat conditions, water pollution, and dam passage.
Pacific lamprey were listed by the
State of Oregon as a sensitive species in 1993 and were given further legal
protected status in 1996. Four species of lamprey, including the Pacific lamprey
were petitioned for listing under the Endangered Species Act in January 2003.
The western brook lamprey lives only in freshwater streams. Smaller than Pacific lamprey, western brook lampreys reach 8 inches in length. Western brook lampreys are non-parasitic and do not feed as adults. The larvae behave similarly to the larvae of the Pacific lamprey.
The river lamprey is anadromous and like the Pacific lamprey adults, are parasitic on marine fish. Little is known about the biology of the river lamprey.
Take a quiz on what you learned about lamprey.
Return to top