American Shad - Alosa sapidissima

American Shad - Photo credit: US Fish and Wildlife

Habitat requirements and life history: From USFW description "American shad (shad) is the largest member of the herring family, averaging between 17 and 24 inches in length and between 3 and 6 pounds in weight at sexual maturity. It is a schooling species and highly migratory. Shad are found along the Atlantic seaboard from Labrador to Florida. Most abundant on the East Coast from Connecticut to North Carolina, shad have spawned, historically, in almost every major river along the Atlantic Coast. Shad are river-specific; each major river along the Atlantic Coast appears to have a discrete spawning stock."

Like Alewife, American Shad are anadromous fish, breeding in freshwater streams. In Massachusetts, shad spawning runs generally occur in May. They spawn in the late afternoon or evening in shallow areas with sand or gravel bottoms. The young form schools and feed in the river until they are about four inches. Out migration to the sea takes place in September to early November when water temperatures drop to 66 degrees (F).

During the summer, adults that survive spawning along with subadults migrate to the Gulf of Maine (or Nantucket Shoals for southern populations) and remain there throughout the summer and early fall. Most move out of the Gulf of Maine in fall as water temperatures decline. During the winter they congregate offshore, between southern Long Island and Nantucket Shoals.

Adult shad are largely filter feeders, gathering zooplankton on their gill rakers, but they will also feed on shrimp and small fishes. The young-of-the-year feed on small zooplankton and insects. (Sources: Hartel, Halliwell, and Launer, 2002. "Inland Fishes of Massachusetts"; Massachusetts Wildlife No. 2, 2000, Special Fishing Issue; U.S. Fish and Wildlife Service, June 1985, Biological Report #82(10.88) Habitat Suitability Index Models and Instream Flow Suitability Curves: American Shad)

Total Length: usually 17-24 inches (can grow larger).