Operculum (gastropod)The operculum (; ) is a corneous or calcareous anatomical structure like a trapdoor that exists in many (but not all) groups of sea snails and freshwater snails, and also in a few groups of land snails; the structure is found in some marine and freshwater gastropods, and in a minority of terrestrial gastropods, including the families Helicinidae, Cyclophoridae, Aciculidae, Maizaniidae, Pomatiidae, etc. The operculum is attached to the upper surface of the foot and in its most complete state, it serves as a sort of "trapdoor" to close the aperture of the shell when the soft parts of the animal are retracted.
Sea slugSea 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 (marine gastropod mollusks) that over evolutionary time have either completely lost their shells, or have seemingly lost their shells due to having a greatly reduced or internal shell. The name "sea slug" is most often applied to nudibranchs, as well as to a paraphyletic set of other marine gastropods without obvious shells.
Terrestrial molluscTerrestrial molluscs or land molluscs (mollusks) are an ecological group that includes all molluscs that live on land in contrast to freshwater and marine molluscs. They probably first occurred in the Carboniferous, arising from freshwater ones. This group includes land snails and land slugs. Loss of the shell has taken place many times in different groups that are not evolutionarily closely related, and land snails and slugs are most often treated together as a single group in specialized malacological literature.
ScleriteA sclerite (Greek σκληρός, sklēros, meaning "hard") is a hardened body part. In various branches of biology the term is applied to various structures, but not as a rule to vertebrate anatomical features such as bones and teeth. Instead it refers most commonly to the hardened parts of arthropod exoskeletons and the internal spicules of invertebrates such as certain sponges and soft corals. In paleontology, a scleritome is the complete set of sclerites of an organism, often all that is known from fossil invertebrates.
Cornu aspersumCornu aspersum (syn. Cryptomphalus aspersus), known by the common name garden snail, is a species of land snail in the family Helicidae, which includes some of the most familiar land snails. Of all terrestrial molluscs, this species may well be the most widely known. It was classified under the name Helix aspersa for over two centuries, but the prevailing classification now places it in the genus Cornu.
Helix pomatiaHelix pomatia, common names the Roman snail, Burgundy snail, or escargot, is a species of large, air-breathing stylommatophoran land snail native to Europe. It is characterized by globular brown shell. It is an edible species. Helix pomatia commonly occurs synanthropically througout its range. The present distribution is considerably affected by dispersion by human and synanthropic occurrences. The northern limits of natural distribution run presumably through central Germany and southern Poland, eastern range limits run through western-most Ukraine and Moldova/Romania to Bulgaria.
Siphon (mollusc)A siphon is an anatomical structure which is part of the body of aquatic molluscs in three classes: Gastropoda, Bivalvia and Cephalopoda (members of these classes include saltwater and freshwater snails, clams, octopus, squid and relatives). Siphons in molluscs are tube-like structures in which water (or, more rarely, air) flows. The water flow is used for one or more purposes such as locomotion, feeding, respiration, and reproduction. The siphon is part of the mantle of the mollusc, and the water flow is directed to (or from) the mantle cavity.
GonochorismIn biology, gonochorism is a sexual system where there are only two sexes and each individual organism is either male or female. The term gonochorism is usually applied in animal species, the vast majority of which are gonochoric. Gonochorism contrasts with simultaneous hermaphroditism but it may be hard to tell if a species is gonochoric or sequentially hermaphroditic. (e.g. Parrotfish, Patella ferruginea). However, in gonochoric species individuals remain either male or female throughout their lives.
Sphincterochila zonata zonataSphincterochila zonata zonata is a subspecies of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Sphincterochilidae. This species lives in deserts in Israel and Egypt. Helix boissieri is the type species of the genus Sphincterochila. The type species was subsequently designated by Henry Augustus Pilsbry in 1895. It is named after botanist Pierre Edmond Boissier. Sphincterochila zonata zonata lives in the Negev desert (Israel), and the Sinai desert in the Sinai Peninsula (Egypt).
CowrieCowrie or cowry () is the common name for a group of small to large sea snails, marine gastropod mollusks in the family Cypraeidae, the cowries. The term porcelain derives from the old Italian term for the cowrie shell (porcellana) due to their similar appearance. The cowrie was the shell most widely used worldwide as shell money. It is most abundant in the Indian Ocean, and was collected in the Maldive Islands, in Sri Lanka, along the Indian Malabar coast, in Borneo and on other East Indian islands, in Maluku in the Pacific, and in various parts of the African coast from Ras Hafun to Mozambique.
