Latin name

Alosa pseudoharengus

Other names

Herring, sawbelly, gray herring, grayback; French: gapareau, gaspereau; Spanish: alosa, pinchagua.

Identification

A small silvery gray with a greenish or bluish tint to its back, the alewife usually has one small dark shoulder spot. It has large eyes with well-developed fatty eyelids. Alewife can be distinguished from other herrings by their lower jaw, which visibly protrudes beyond the upper jaw.

Distribution

Distributed from Newfoundland and the Gulf of St. Lawrence to South Carolina, it has been introduced into the upper Great Lakes and many other inland waters, although some natural populations are landlocked.

Habitat

Anadromous fish, live in coastal waters, estuaries, and some inland waters, some spend their entire lives in freshwater. In shelf waters, they are caught up to 70 miles offshore.

Size

Usually averaging 6 to 12 inches in salt water and 3 to 6 inches in fresh water, they can grow up to half a pound in weight and up to 15 inches in length.

Life history and Behavior

In late April/early June, they move up freshwater rivers from the sea and spawn in lakes and sluggish sections of rivers. They move from deeper water to coastal shallows in lakes or upstream in rivers and spawn when water temperatures range from 52° to 70° F. Females lay 60,000 to 100,000 eggs in salt water and 10,000 to 12,000 eggs in fresh water. They lay eggs haphazardly, at night, leaving the eggs unattended. The fry hatch in less than a week and return to the sea or deeper waters by fall.

Food and feeding habits

Juveniles feed on small plants, animals, algae, copepods and ostracods. Adults feed on plankton, insects, shrimp, small fish, diatoms, copepods, and their eggs.

Reproduction

No information