Tennessee Wildlife Resources Agency

TWRA's Region 4 - East Tennessee

Reservoir Fisheries Management Program

Alewife - Alosa pseudoharengus

(This page was last updated - 06/11/2007)

Scientific name: Alosa pseudoharengus (pseudo "false", harengus "herring")

Common names: Alewife, Alewives, River Herring, Sawbelly, Gaspereau, Golden Shad, Gray Herring

Alewife
Alewife
Watts Bar and Norris Reservoir alewife - photo by Jim Negus

Species Overview

Alewife can be found in most East Tennessee reservoirs with the exception of Douglas, Calderwood, and Chilhowee. They are one of two "river herring" native to the Atlantic Coast that supported one of the oldest U.S. commercial fisheries until its decline in the 1970's. They are eaten fresh, dried, smoked, or fried and their eggs (roe) are considered a delicacy.

Alewife were introduced into Watauga and Dale Hollow Reservoirs by the TWRA in 1976. This species has since expanded its range via downstream migration and "bait bucket" introductions. They were introduced to provide additional forage in cool water reservoirs that typically experience winter die-offs of threadfin shad. Biologists have come to regret the introduction, however, because they have adversely affected the natural reproductive capabilities of walleye.

 

Shad ID
Key to east Tennessee clupeids - by Jim Negus

Identification

Alewife are separated from their cousins, threadfin and gizzard shad, by not having an elongated dorsal fin ray. It is very difficult to separate alewife from blueback herring without dissecting the abdominal cavity. The peritoneum lining of an alewife is pale to lightly pigmented while that of a blueback's is jet black.

Alewife look very similar to young skipjack herring, however the lower jaw of an adult skipjack extends much farther beyond the upper. Skipjack also reach considerably larger size than do either alewife or blueback herring. Skipjack have the same peritoneum characteristics as alewife.

 

River Herring Key
Peritoneum characteristics of blueback herring and alewife - by Jim Negus

Habits

Alewife prefer cooler water than gizzard or threadifn shad and are typically found along or below the thermocline in the summer. They are also found in tailwaters throughout the year. Adults can withstand temperatures up to 77 F while young-of-the-year can live in waters up to 86 F. They are light sensitive and tend to be in deeper water during the day. Adults are piscivorous (fish eaters), but young and adults feed primarily on zooplankton strained from the water with their gill rakers.

Alewife Close-up
Facial characteristics of an alewife - photo by Jim Negus

Life Cycle

Spawning occurs in shallow water from April to May. They swim to the surface in contact with each other, releasing eggs and milt, creating considerable surface disruption. Females produce 10-22,000 adhesive eggs that sink (demersal eggs) and temporarily attach to plants or rocks, but later settle to the substrate. Alewife may live up to 5-6 years in our reservoirs and reach 14-inches, but individuals greater than 6-inches are rare.

References

Etnier, D. and W. Starnes. 1993. The Fishes of Tennessee. The University of Tennessee Press.

 

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