An amphipod is a type of small, shrimp-like crustacean found in various aquatic environments, including oceans, rivers, and lakes. They belong to the order Amphipoda and are characterized by their laterally compressed bodies, which allow them to swim efficiently. Amphipods play a crucial role in the food web, serving as a food source for many fish and other marine animals. These creatures typically range in size from 1 to 10 centimeters and exhibit a variety of colors and shapes. Some well-known examples of amphipods include the sand flea and the deep-sea amphipod, which can thrive in extreme ocean depths. Their adaptability makes them important indicators of environmental health.