Home → Fish & Wildlife → Fisheries → Species Information → Alewife
Common Name: Alewife
Other Names: Sawbelly
Scientific Name: Alosa Pseudoharengus
Adult Size: Young of the year, alewives reach a length of 2 to 3 inches by their first fall and are usually 4 to 6 inches long at maturity. Males reach sexual maturity at age 2 and females mature at age 3.
Identification: Alewives are predominantly silver, except for a grayish green back. There is also a single black spot just behind the head at eye level. The common name "sawbelly" originates from the very distinctive overlapping scales along the belly that creates a saw-like keel.
Life History: Maine alewives have two distinct life history strategies. Sea-run alewives are anadromous, spending most of their lives at sea before returning to Maine’s inland waters to spawn. Landlocked alewives complete their entire life cycle in freshwater and were first stocked in Maine lakes in 1966.