Amphipods are small, shrimp-like crustaceans found in various aquatic environments, including oceans, rivers, and lakes. They typically measure between 1 to 10 centimeters in length and have a laterally compressed body, which helps them 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 are known for their diverse habitats, ranging from deep-sea environments to coastal areas and even freshwater ecosystems. Some species, like the Gammarus, are commonly found in freshwater, while others inhabit the deep ocean, contributing to the overall biodiversity of their ecosystems.