Summary ²

Family: Clupeidae

Alewives(Alosa pseudoharengus) are possibly native to Lake Ontario, but spread to the rest of the Great Lakes through the Welland Canal. They became incredibly abundant and experienced mass die-offs, resulting in millions of dead fish washing up on beaches. Their numbers are lower now, and die-offs are far less frequent and smaller in magnitude. Eat plankton and smaller organisms, including larval fishes. Alewives in turn are the favorite food of salmons. Have had a significantly negative impact on native fishes.

How to recognize: Very thin. Serrations along the belly look like a saw’s teeth. Dark blotch behind the head. An elongated scale above the fin along the belly. Does NOT have a filament extending from the fin on the back. Mouth is upturned. Up to 10 inches /25 centimeters long.

Sources and Credits

1. (c) alavire, all rights reserved
2. (c) alavire, some rights reserved (CC BY-NC)

More Info

• iNat taxon page
• Animal Diversity Web
• Biodiversity Heritage Library
• BOLD Systems BIN search
• FishBase
• FishSource
• Global Biodiversity Information Facility (GBIF)
• Maryland Biodiversity Project
• NatureServe Explorer 2.0
• VertNet
• World Register of Marine Species

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