A seashell or sea shell, also known simply as a shell, is a hard, protective outer layer usually created by an animal or organism 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 decomposed or been eaten by another animal.
Conch is a common name of a number of different medium-to-large-sized sea snails. Conch shells typically have a high spire and a noticeable siphonal canal.
Sinistral and dextral, in some scientific fields, are the two types of chirality ("handedness") or relative direction. The terms are derived from the Latin words for "left" (sinister) and "right" (dexter). Other disciplines use different terms or simply use left and right.
A spire is a part of the coiled shell of molluscs. The spire consists of all of the whorls except for the body whorl. Each spire whorl represents a rotation of 360°. A spire is part of the shell of a snail, a gastropod mollusc, a gastropod shell, and also the whorls of the shell in ammonites, which are fossil shelled cephalopods.
The operculum is a corneous or calcareous anatomical structure like a trapdoor that exists in many 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.
Dakshinavarti shankha, also referred to as Valampuri shankhu and Sri Lakshmi shankha is a sacred Hindu conch. It refers to the shell of a large sea snail from the Indian Ocean, but one that has a rare reverse-turning spiral.
A shankha has religious ritual importance in Hinduism.
Turbonillinae is a subfamily of mostly minute parasitic sea snails, marine gastropod molluscs in the family Pyramidellidae, the pyrams and their allies.
Odostomellini is a taxonomic tribe of minute sea snails, marine gastropod molluscs within the family Pyramidellidae the pyrams and their allies.
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 in some cases the shell is reduced such that the body cannot be retracted within it (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.
Planorbidae, common name the ramshorn snails or ram's horn snails, is a family of air-breathing freshwater snails, aquatic pulmonate gastropod molluscs. Unlike most molluscs, the blood of ram's horn snails contains iron-based hemoglobin instead of copper-based hemocyanin. As a result, planorbids are able to breathe oxygen more efficiently than other molluscs. The presence of hemoglobin gives the body a reddish colour. This is especially apparent in albino animals.
Planorbarius corneus, common name the great ramshorn, is a relatively large species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails, or planorbids, which all have sinistral or left-coiling shells.
Neoplanorbis is a genus of small, freshwater, air-breathing snails. They are aquatic pulmonate gastropod mollusks in the family Planorbidae, the ram's horn snails.
Turbinella is a genus of very large sea snails with an operculum, marine gastropod mollusks in the subfamily Turbinellinae of the family Turbinellidae.
Melo melo, common name the Indian volute or bailer shell, is a very large edible sea snail, a marine gastropod mollusc in the family Volutidae, the volutes.
Conch, or conque, also known as a "seashell horn" or "shell trumpet", is a wind instrument that is made from a conch, the shell of several different kinds of sea snails. Their natural conical bore is used to produce a musical tone. Conch shell trumpets have been played in many Pacific Island countries, as well as South America and Southern Asia.
Turbinella angulata, common name the West Indian chank shell or Lamp Shell, is a species of very large tropical sea snail with a gill and an operculum, a marine gastropod mollusk in the family Turbinellidae.
Volema pyrum is a species of sea snail, a marine gastropod mollusk in the family Melongenidae, the crown conches and their allies.
Volema is a genus of sea snails, marine gastropod molluscs in the family Melongenidae, the crown conches and their allies.
Left-right asymmetry is the process in early embryonic development that breaks the normal symmetry in the bilateral embryo. In vertebrates, left-right asymmetry is established early in development at a structure called the left-right organizer and leads to activation of different signalling pathways on the left and right of the embryo. This in turn cause several organs in adults to develop LR asymmetry, such as the tilt of the heart, the different number lung lobes on each side of the body and the position of the stomach and spleen on the right side of the body. If this process does not occur correctly in humans it can result in the syndromes heterotaxy or situs inversus.
