Alaska Department of Fish and Game
Secondary Site Navigation
Did You Know?
Juvenile lamprey lack eyes or the disk-like mouths of adult lamprey
The Arctic lamprey is a small eel-like fish up to 15 inches in total length. Arctic lampreys are distinguished from other Alaska lampreys by two large teeth on the supraoral bar and the presence of a row of posterial teeth.
Adult Arctic lampreys are blue-black to dark brown on the dorsal side and yellow to light brown on the ventral side with light tan to gray fins. Adult Arctic lampreys have a dark blotch on the posterior dorsal fin and the tail. The body of juvenile Arctic lamprey is usually gray above and lighter below. The anal fin of the female Arctic lamprey is noticeably larger than that of a male, while female Arctic lampreys lack urogenital papilla.
Growth and Reproduction
Arctic lampreys are anadromous, which means it spends part of its life in the ocean and part of its life in fresh water. Anadromous Arctic lampreys may spend months moving to the cool, clear headwaters of streams to make their nest or redds. Both males and females participate in redd building in stream riffles by removing small rocks with their mouths and fanning smaller particles with their tails. Males and females intertwine while simultaneously depositing sperm and eggs into the redd. Depending on her size, a single female can release up to 100,000 eggs. The adults die soon after egg fertilization. The eggs hatch in freshwater in 7 to 14 days depending on the water temperature. Larval forms of lampreys, referred to as ammocoetes, are born without eyes and lack sucking mouthparts. Lampreys remain at this stage for three to seven years before metamorphosing in adults, which includes the development of a sucking mouth, eyes, and teeth.
Ammocoetes burrow into the silt or mud of shallow pools and eddies of clear streams and feed by filtering microorganisms, algae, and detritus from the water. Anadromous adult lampreys parasitize other organisms such as other species of fish or even marine mammals by using their sucking mouthparts to attach themselves to the host's body. They then use their teeth to cut through the scales and skin to get to the host's blood and body fluid.
Parasitic adult lampreys migrate to the sea after metamorphosing into adults and tend to spend one to four years in the marine environment before returning to freshwater to eventually spawn. Anadromous lampreys return to fresh water in the fall and overwinter until spring when they spawn. Lampreys tend to migrate upstream in large groups and once upstream migration commences lampreys do not feed.
Range and Habitat
In Alaska, Arctic lampreys are found from the Kenai Peninsula north along Bering Sea drainages and east along the Arctic coast to the Anderson River. Arctic lampreys also occur in the Yukon, Kuskokwim, and Tanana river drainages and around St. Lawrence Island.
Status, Trends, and Threats
Population discreteness for Arctic lampreys within and among river systems in Alaska is unknown, as very little information exists on Arctic lampreys in general. It is clear that an understanding of Arctic lamprey genetic population structure is necessary to identify appropriate management units for maintenance of biodiversity and productivity.
Overall strength of Arctic lamprey returns varies across the state by year and location. Why run strength remains strong in some areas while weak in other areas is unclear.
Potential overharvest from commercial, personal use or subsistence fisheries is the main threat to the resource.
The Arctic lamprey is a small fish known to reach a length of over 15 inches, but generally smaller.
From the Kenai Peninsula north along Bering Sea drainages and east along Arctic Ocean drainage as far as the Anderson River.
Juveniles are filter feeders of microorganisms and organic matter from the sediment. Adults feed by attaching parasitically to various species of fish such as salmon or sharks.
A variety of fishes, birds, and river otters.
Female Arctic lamprey can produce up to 100,000 eggs and die after spawning.
Managed by the Alaska Department of Fish & Game in Alaska state waters.