A snail is 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.
Gastropods, commonly known as slugs and snails, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda.
The radula is an anatomical structure used by mollusks for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus. The radula is unique to the mollusks, and is found in every class of mollusk except the bivalves, which instead use cilia, waving filaments that bring minute organisms to the mouth.
Banana slugs (Ariolimax) are a genus of North American terrestrial slugs in the family Ariolimacidae.
Sea slug is a common name for some marine invertebrates with varying levels of resemblance to terrestrial slugs. Most creatures known as sea slugs are gastropods, i.e. they are sea snails that, over evolutionary time, have either entirely lost their shells or have seemingly lost their shells due to having a significantly reduced or internal shell. The name "sea slug" is often applied to nudibranchs and a paraphyletic set of other marine gastropods without apparent shells.
The black slug, Arion ater, is a large terrestrial gastropod mollusk in the family Arionidae, the round back slugs. Many land slugs lack external shells, having a vestigial shell. Most slugs retain a remnant of their shell, which is usually internalized, unlike other terrestrial mollusks which have external shells. Without such shells, slugs produce mucus, that may also contain toxins—to deter predators. Terrestrial slugs produce two other forms of mucus that facilitate locomotion and prevent death from drying. Such mollusks are hermaphroditic. Slugs most often function as decomposers but are also often omnivores. Arion ater is one such slug, decomposing organic matter, preying on other organisms, and consuming vegetative matter including agricultural crops. Native to Europe, the black slug is an invasive species in Australia, Canada, and the United States.
A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. Land snail is the common name for terrestrial gastropod mollusks that have shells. However, it is not always easy to say which species are terrestrial, because some are more or less amphibious between land and fresh water, and others are relatively amphibious between land and salt water.
Philomycidae are a family of air-breathing land slugs. They are terrestrial pulmonate gastropod mollusks in the superfamily Arionoidea.
Aeolidia papillosa, known as the common grey sea slug, is a species of nudibranch in the family Aeolidiidae.
Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc. The word slug is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a small internal shell, particularly sea slugs and semi-slugs.
A love dart is a sharp, calcareous or chitinous dart which some hermaphroditic land snails and slugs create. Love darts are both formed and stored internally in a dart sac. These darts are made in sexually mature animals only, and are used as part of the sequence of events during courtship, before actual mating takes place. Darts are quite large compared to the size of the animal: in the case of the semi-slug genus Parmarion, the length of a dart can be up to one fifth that of the semi-slug's foot.
Philomycus togatus, also known as the toga mantleslug, is a species of land slug, a terrestrial pulmonate gastropod mollusk in the family Philomycidae.
Elysia pusilla is a species of small sea slug, a marine gastropod mollusk in the family Plakobranchidae. It is a sacoglossan.
Philomycus is a genus of air-breathing land slugs in the family Philomycidae, the mantleslugs.
Philomycus virginicus, common name Virginia mantleslug, is a species of air-breathing land slug, a terrestrial pulmonate gastropod mollusk in the family Philomycidae.
The reproductive system of gastropods varies greatly from one group to another within this very large and diverse taxonomic class of animals. Their reproductive strategies also vary greatly.
Pontohedyle is a genus of sea slugs, acochlidians, shell-less marine gastropod mollusks in the family Parhedylidae. Sea slugs in this genus are highly simplified and uniform.
The mating of gastropods is a vast and varied topic, because the taxonomic class Gastropoda is very large and diverse, a group comprising sea snails and sea slugs, freshwater snails and land snails and slugs. Gastropods are second only to the class Insecta in terms of total number of species. Some gastropods have separate sexes, others are hermaphroditic. Some hermaphroditic groups have simultaneous hermaphroditism, whereas some sequential hermaphroditism. In addition, numerous very different mating strategies are used within different taxa.
Rathouisia pantherina is a species of carnivorous air-breathing land slug, terrestrial pulmonate gastropod mollusk in the family Rathouisiidae.
