Waterfowl-food
Guides
Hyalella azteca
scud, freshwater scud
Hyalella azteca is a widespread and abundant amphipod crustacean in North America, reaching 3–8 mm in length. It inhabits fresh and brackish waters across a broad geographic range from Central America to the Arctic tree line. The species is a significant food source for waterfowl and serves as a standard test organism in aquatic ecotoxicology and sediment toxicity assessments.