Small crustaceans are tiny aquatic animals that belong to the class Crustacea. They typically have a hard exoskeleton, jointed legs, and segmented bodies. Common examples include shrimp, crabs, and copepods. These creatures can be found in various environments, from oceans and rivers to ponds and marshes. These crustaceans play essential roles in their ecosystems, serving as both predators and prey. They are important food sources for larger animals, including fish and birds. Additionally, small crustaceans contribute to the breakdown of organic matter, helping to maintain the health of aquatic habitats.