腹足纲, or Gastropoda, is a large class of mollusks that includes snails and slugs. These creatures are characterized by their soft bodies, which are often protected by a coiled shell, although some species, like slugs, lack a shell. They are found in a variety of habitats, including oceans, freshwater, and terrestrial environments. Gastropods exhibit a unique form of movement using a muscular foot located on their underside. They are known for their diverse feeding habits, with some being herbivores, while others are carnivorous or detritivores. This class plays a significant role in ecosystems, contributing to nutrient cycling and serving as food for various predators.