Definition of water shrimp in English:

water shrimp

noun

rare
  • Any of various shrimplike crustaceans living in fresh water; especially an amphipod of the genus Gammarus or family Gammaridae, as the common European Gammarus pulex (now usually called freshwater shrimp).

Origin

Mid 18th century; earliest use found in William Ellis (c1700–1758), agriculturist and writer.