include shrimps, crabs, lobsters, crayfish, copepods, and barnacles. There are about 26,000 species alive today.
They have adapted to most types of food sources.
Their appendages can be modified into a variety of forms.
Some are very small aquatic animals (such as fairy shrimp and copepods)
which are important in aquatic food chains.
Sowbugs are crustaceans often found under rotting logs.
The largest crustaceans in