Light micrograph of a common freshwater shrimp (Gammarus pulex). This amphipod crustacean is found in streams, rivers, and other aquatic habitats throughout Europe and northern Asia. It is an important part of the food chain in freshwater ecosystems, serving as a food source for a variety of fish, birds, and other aquatic organisms. It has a hard exoskeleton and jointed legs, which allow it to move and swim in the water. The body is typically brown or green in colour, with a mottled appearance that provides camouflage in its natural habitat.