Species contact: Bradford Chase
Scientific name: Alosa pseudoharengus
Common names: Alewife, river herring, sawbelly, freshwater herring
Size: 15 inches, averaging 10-11 inches and 8-9 ounces
Color: Grey green dorsally, fading to pale gray green on the sides and silver on the belly; dark spot directly behind the operculum (gill cover)
Body: Compressed slightly laterally, deep belly; large mouth and eyes, small head, small fins except caudal, single dorsal fin, pelvic fin directly below dorsal
Blueback herring (Alosa aestivalis), American shad (Alosa sapidissima)
Prey: small fishes, copepods, small shrimps
Predators: Large fishes, sharks, baleen whales
Alewife are a diadromous species. They live in saltwater, returning to freshwater to spawn. Spawning occurs in early spring. Females lay anywhere from 60,000 to 100,000 eggs. Eggs sink after spawning occurs and stick to anything they touch, hatching about 6 days later. Young look like adults immediately. Roughly a month after hatching, they begin to make their way to the ocean. Alewives return annually to their parent stream.
When spawning, adults go into rivers with gravel or clean sand. In open water, they are roughly 90-180 feet deep.
Western North Atlantic Ocean from Northern Nova Scotia, Canada south to North Carolina
Federal waters (3 miles to 200 miles): NOAA Fisheries based on recommendations from the New England Fishery Management Council
State waters (coast to 3 miles): Massachusetts Division of Marine Fisheries based on the requirements from the Atlantic States Marine Fisheries Commission