gastropodoista

Gastropoda, commonly known as gastropods, are a large and diverse group of mollusks characterized by their single, spiral shell. They are one of the most successful and widespread groups of invertebrates, with over 80,000 known species. Gastropods are found in various habitats, including marine, freshwater, and terrestrial environments. They exhibit a wide range of sizes, from microscopic to large, with some species reaching lengths of over a meter.

Gastropods are bilaterally symmetrical and have a distinct head, foot, and visceral mass. The head is typically retractable into the shell, and the foot is used for locomotion and manipulation. The visceral mass contains the internal organs, including the digestive system, reproductive organs, and nervous system. Gastropods are hermaphroditic, meaning they possess both male and female reproductive organs, although they may not be functional at the same time.

The shell of gastropods is typically coiled in a spiral, with the apex pointing forward. The shell is composed of calcium carbonate and is secreted by the mantle, a fold of tissue that lines the inner surface of the shell. The shell serves as a protective covering and provides buoyancy in aquatic environments. Some gastropods, such as the nudibranchs, have lost their shell entirely.

Gastropods play important roles in various ecosystems. They are a significant food source for many animals, including birds, fish, and mammals. Some species are also used as food by humans. Gastropods are also important in scientific research, as they provide valuable insights into the evolution of mollusks and the development of complex body plans.