Biotic-resistance
Guides
Gammarus
scuds, freshwater shrimp, sideswimmers
Gammarus is a genus of amphipod crustaceans in the family Gammaridae, containing over 200 described species and representing one of the most species-rich crustacean genera. Species occupy diverse aquatic habitats ranging from purely freshwater to estuarine and marine environments, with salinity tolerance varying markedly among species. The genus is widely distributed throughout the Holarctic region, with additional species extending into tropical Southeast Asia. Gammarus species serve important ecological functions as shredders and predators in aquatic food webs.