Pulmonates

Pulmonates are a large, informal group of air-breathing gastropods within the class Gastropoda, comprising most land snails and slugs as well as several freshwater snails. They are characterized by a lung-like mantle cavity that functions as a vascularized pneumostome, enabling respiration with air rather than gills. Gas exchange occurs through this opening, and the mantle cavity forms a dedicated lung in most species.

Taxonomically, Pulmonata was historically treated as a subclass or order of Gastropoda. Modern classifications often regard the traditional Pulmonata as paraphyletic, using clades such as Eupulmonata to reflect evolutionary relationships more accurately. As a result, the term Pulmonata is commonly used in informal or historical contexts rather than as a formal taxonomic grouping.

Anatomy and diversity vary widely within pulmonates. Many land-dwelling species (the typical "land snails" and many slugs) have reduced or absent shells, while freshwater pulmonates include species with external shells. Planorbidae (ram’s horn snails) are a notable freshwater familia with planispiral shells. Slugs lack an external shell or possess only a vestigial one. Most pulmonates are hermaphroditic, and mating routines can be elaborate; reproduction typically involves laying eggs in moist soil or leaf litter, though some species give birth to young.

Habitat and ecology cover terrestrial and freshwater environments, with a general preference for moist conditions. Diets are mainly herbivorous or detritivorous, feeding on plant material, fungi, and decomposing matter; some species may be omnivorous or opportunistic.

Pulmonates play significant ecological roles as herbivores and detritivores, contribute to nutrient cycling, and serve as prey for various predators. They also include several species that are agricultural pests and others used as bioindicators of environmental moisture and habitat quality.