Alewife - Alosa pseudoharengus


The herring family, related to the anchovies, has about 180 species world-wide. Six species are common in Massachusetts: three species found only in coastal waters (Hickory Shad, Atlantic Herring, and Atlantic Menhaden) and three anadromous species (American Shad, Alewife, and Blueback Herring). Of these three, two species (Alewife and American Shad) were found historically in the Assabet River. Alewife and blueback herring, collectively referred to as river herring, are relatively small members of the herring family.

Habitat requirements and life history: Alewifes and American Shad are similar looking, but the Alewife are generally smaller (10-12 inches vs. 17-24 inches).

Alewifes are anadromous, spending most of their adult life in the ocean waters near their natal river and returning to freshwaters to spawn. In the spring, when water temperatures reach about 52 degrees F, schools of Alewife swim upstream spawning numerous times over several days. They spawn in the slow-moving, shallow backwaters of streams and in lakes and then swim back downstream passing other schools on their way upstream. After hatching, schools of the young herring work their way slowly downstream. Alewife become sexually mature in three years and may live up to nine years making the trip upstream to spawn multiple times in their lives. Adult Alewifes feed on zooplankton, small fishes, and crustaceans. Young-of-the-year feed on zooplankton. (Sources: Hartel, Halliwell, and Launer, 2002. "Inland Fishes of Massachusetts")

Also see USFW description

Photo credit: US Fish and Wildlife

Total length: 10-12 inches (range 9-15 inches).