A snail is, in loose terms, a shelled gastropod. The name is most often applied to land snails, terrestrial pulmonate gastropod molluscs. However, the common name snail is also used for most of the members of the molluscan class Gastropoda that have a coiled shell that is large enough for the animal to retract completely into. When the word "snail" is used in this most general sense, it includes not just land snails but also numerous species of sea snails and freshwater snails. Gastropods that naturally lack a shell, or have only an internal shell, are mostly called slugs, and land snails that have only a very small shell are often called semi-slugs.
The gastropods, more commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca, called Gastropoda. This class comprises snails and slugs from saltwater, from freshwater, and from the land. There are many thousands of species of sea snails and slugs, as well as freshwater snails, freshwater limpets, and land snails and slugs.
Powelliphanta is a genus of large, air-breathing land snails, pulmonate gastropods in the family Rhytididae, found only in New Zealand. They are carnivorous, eating invertebrates, mostly native earthworms. Often restricted to very small areas of moist forest, they are prey to introduced mammalian predators, and many species are threatened or endangered.
The grove snail or brown-lipped snail is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusc. It is one of the most common species of land snail in Europe, and has been introduced to North America.
Sea snail is a common name for snails that normally live in salt water, in other words marine gastropods. The taxonomic class Gastropoda also includes snails that live in other habitats, such as land snails and freshwater snails. Many species of sea snails are edible and exploited as food sources by humans.
The gastropod shell is part of the body of a gastropod or snail, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium storage. Some gastropods appear shell-less (slugs) but may have a remnant within the mantle, or the shell is reduced such that the body cannot be retracted within (semi-slug). Some snails also possess an operculum that seals the opening of the shell, known as the aperture, which provides further protection. The study of mollusc shells is known as conchology. The biological study of gastropods, and other molluscs in general, is malacology. Shell morphology terms vary by species group. An excellent source for terminology of the gastropod shell is "How to Know the Eastern Land Snails" by John B. Burch now freely available at the Hathi Trust Digital Library.
Arianta arbustorum is a medium-sized species of land snail, sometimes known as the "copse snail", a terrestrial pulmonate gastropod mollusk in the family Helicidae.
Physidae, common name the bladder snails, is a monophyletic taxonomic family of small air-breathing freshwater snails, aquatic pulmonate gastropod molluscs in the clade Hygrophila.
Amphidromus is a genus of tropical air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Camaenidae. The shells of Amphidromus are relatively large, from 25 mm (0.98 in) to 75 mm (3.0 in) in maximum dimension, and particularly colorful. During the 18th century, they were among the first Indonesian land snail shells brought to Europe by travelers and explorers. Since then, the genus has been extensively studied: several comprehensive monographs and catalogs were authored by naturalists and zoologists during the time period from the early 19th to the mid 20th centuries. Modern studies have focused on better understanding the evolutionary relationships within the group, as well as solving taxonomic problems.
Opisthostoma mirabile is a species of air-breathing land snail with an operculum, a terrestrial gastropod mollusk in the family Diplommatinidae.
Camaenidae is a family of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Helicoidea, the typical snails and their allies. This is one of the most diverse families in the clade Stylommatophora.
Opisthostoma everettii is a species of air-breathing land snail with an operculum, a terrestrial gastropod mollusk in the family Diplommatinidae.
Opisthostoma stellasubis is a species of land snail with an operculum, a terrestrial gastropod mollusk in the family Diplommatinidae.
Opisthostoma shelfordi is a species of air-breathing land snail with an operculum, a terrestrial gastropod mollusk in the family Diplommatinidae.
Opisthostoma lituus is a species of air-breathing land snail with an operculum, a terrestrial gastropod mollusk in the family Diplommatinidae.
Opisthostoma pulchellum is a species of air-breathing land snail with an operculum, a terrestrial gastropod mollusk in the family Diplommatinidae.
Opisthostoma hosei is a species of air-breathing land snail with an operculum, a terrestrial gastropod mollusk in the family Diplommatinidae.
Opisthostoma grandispinosum is a species of air-breathing land snail with an operculum, a terrestrial gastropod mollusk in the family Diplommatinidae.
In the shell of gastropod mollusks, the lip is the free margin of the peristome or aperture of the gastropod shell.
