Features: The Northern Brook Lamprey (Ichthyomyzon fossor) has the characteristic features of lampreys -- a round mouth and teeth arranged in a circle -- but this species is non- parasitic and the larvae feed on diatoms and protozoans. This species is small (9-16 cm long) and is easily confused with other native lampreys. As indicated by its common name, this species lives in small rivers. Adults spawn in gravelly riffles and then die. Individuals can lay over 1,000 eggs. When the larvae (called ammocoetes) hatch they make burrows in soft mud and spend six years growing. Then they metamorphose into an immature adult stage which lasts over winter (about 8 months) and then they develop sexual maturity quickly, emerge from the mud and disperse as adults to the spawning grounds. Adults never feed and live for about a year before dying.

Status: Special Concern Provincially and Nationally

Range: The Northern Brook Lamprey lives in the eastern United States in the upper Mississippi and southern Hudson Bay drainages, ranging from Manitoba and the Great Lakes region south to Missouri, east to the St. Lawrence River. In Ontario, it lives in rivers draining into Lakes Superior, Huron and Erie, and in the Ottawa and St. Lawrence Rivers. Range Maps

Threats: The Northern Brook Lamprey prefers warm water and it may never have been common here. Ontario populations have declined because of the application of non-selective chemicals in streams to control the introduced Sea Lamprey, which is a parasitic species and a threat to Great Lakes fisheries. The species persists in untreated streams, above barriers and in backwater areas, which are not affected by the treatments. Water drawdowns and siltation are also potential threats.

Protection: The species has the general protection given by habitat sections of the Fisheries Act.

Text Sources: COSEWIC 2007; Lanteigne 1991

Last Modified Date: May 2008