“Child with crayfish” by USFWS Headquarters is licensed under CC BY 2.0

Crayfish and shrimp are some of the crustaceans that can live in a coldwater stream. Both kinds of animals have five pairs of legs. But crayfish look a lot like mini-lobsters—they usually have claws, and they use their tails to swim backwards. Freshwater shrimp are often smaller than crayfish. Their bodies can be curved, and they are very thin animals.