Answer: in water
Step-by-step explanation:
Crustaceans are very successful arthropods, including marine, freshwater and terrestrial animals, popularly known as crabs, lobsters, crayfish, hermit crabs and a large number of species known as shrimps. As a group, crustaceans are primitive and predominantly marine: of the approximately 39,000 known species, 84% live in salty or brackish waters, 13% live in freshwater and only 3% have adapted to the terrestrial environment.