A seashell or sea shell, also known simply as a shell, is a hard, protective outer layer usually created by an animal that lives in the sea. The shell is part of the body of the animal. Empty seashells are often found washed up on beaches by beachcombers. The shells are empty because the animal has died and the soft parts have been eaten by another animal or have decomposed.
The gastropods, commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda.
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 actually gastropods, i.e. they are sea snails 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.
Heterobranchia, the heterobranchs, is a taxonomic clade of snails and slugs, which includes marine, aquatic and terrestrial gastropod mollusks.
Triplofusus papillosus, previously known as Pleuroploca gigantea, common name the Florida horse conch, is a species of extremely large predatory subtropical and tropical sea snail, a marine gastropod mollusc in the family Fasciolariidae, the spindle snails, tulip snails and their allies.
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the ammonites.
Philinoidea is a taxonomic superfamily of sea slugs, specifically headshield slugs, marine gastropod mollusks in the clade Cephalaspidea.
Struthiolariidae is a family of small to medium-sized sea snails, marine gastropod molluscs in the superfamily Stromboidea.
The Vermetidae, the worm snails or worm shells, are a taxonomic family of small to medium-sized sea snails, marine gastropod molluscs in the clade Littorinimorpha. The shells of species in the family Vermetidae are extremely irregular, and do not resemble the average snail shell, hence the common name "worm shells" or "worm snails".
A micromollusk is a shelled mollusk which is extremely small, even at full adult size. The word is usually, but not exclusively, applied to marine mollusks, although in addition, numerous species of land snails and freshwater mollusks also reach adult size at very small dimensions.
Turritellidae, common name the "tower shells" or "tower snails", is a taxonomic family of small to medium-sized sea snails, marine gastropod molluscs in the clade Sorbeoconcha.
Dotidae are a taxonomic family of small sea slugs, nudibranchs, shell-less marine gastropod molluscs formerly assigned to the order Opisthobranchia, but now considered to belong to the clade Dexiarchia. This family is unassigned to a superfamily.
Peltospiridae is a small family of gastropods that used to belong to the clade Vetigastropoda, but is now included in the clade Neomphalina
Solariellidae is a family of small sea snails, marine gastropod mollusks in the superfamily Trochoidea.
Vetigastropoda is a major taxonomic group of sea snails, marine gastropod mollusks that form a very ancient lineage. Taxonomically the Vetigastropoda are sometimes treated as an order, although they are treated as an unranked clade in Bouchet and Rocroi, 2005.
The Cladobranchia are a taxonomic clade of nudibranchs, sea slugs, marine gastropod molluscs in the clade Dexiarchia.
Costellariidae sometimes called the "ribbed miters" is a taxonomic family of minute to medium-sized predatory sea snails, marine gastropod mollusks. This family of snails is also sometimes referred to as Vexillum miters. The main family of miter shells however is Mitridae, a closely related group.
Freshwater snails are gastropod mollusks which live in fresh water. There are many different families. They are found throughout the world in various habitats, ranging from ephemeral pools to the largest lakes, and from small seeps and springs to major rivers. The great majority of freshwater gastropods have a shell, with very few exceptions. Some groups of snails that live in freshwater respire using gills, whereas other groups need to reach the surface to breathe air. In addition, some are amphibious and have both gills and a lung. Most feed on algae, but many are detritivores and some are filter feeders.
Strioturbonilla sigmoidea is a species of sea snail, a marine gastropod mollusk in the family Pyramidellidae, the pyrams and their allies.
Turbonilla nicholsi is a species of sea snail, a marine gastropod mollusk in the family Pyramidellidae, the pyrams and their allies.
