Alewife and Similar Species
Alosa pseudoharengus
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Open the appSeveral fish can be confused with Alewife. Here are the key differences.
Species often confused with {name}
Blueback Herring
Alosa aestivalis
Key differences: Blueback Herring typically have a darker, bluish back, smaller eyes relative to head length, and a dark peritoneum (lining of the body cavity) compared to the Alewife's pale peritoneum. The dark spot behind the operculum is usually less distinct or absent in Blueback Herring. Spawning runs often occur slightly later than Alewives.
Atlantic Herring
Clupea harengus
Key differences: Atlantic Herring are generally more slender and elongated than Alewives, lack the distinct dark spot behind the operculum, and do not possess the sharp, saw-toothed ventral keel. They are primarily marine and do not undertake extensive freshwater spawning migrations.
American Shad
Alosa sapidissima
Key differences: American Shad are significantly larger than Alewives, have a more elongated body, and typically have a series of 1-4 dark spots along their sides behind the operculum (though these can be faint). Their scales are also larger and less easily dislodged than those of Alewives.
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