Calyptraea chinensis
Encyclopedia
Calyptraea chinensis, common name
the Chinese hat snail or Chinese hat shell, is a species
of small sea snail
, a marine gastropod mollusk in the family
Calyptraeidae
, the slipper snails or slipper limpets, cup-and-saucer snails, and Chinese hat snails.
of this species has the shape of an almost symmetrical cone (like a Chinese hat or conical Asian hat), 7 mm high and 15 – 21 mm wide. The internal partition has a spirally curved edge which runs running from the apex
to the margin of the shell, and partly covers the aperture
. The presence of this internal shelf distinguishes this species easily from the true limpets. The aperture is round and adapted to the substrate. The shell is creamy white, and glossy on the inside.
Calyptraea chinensis is a filter feeder
, binding fine food particles with mucus
. Like all slipper limpets, this species is a protandrous
hermaphrodite
, but the stages of change from male to female have not been clearly defined. Unlike Crepidula fornicata (the American slipper limpet), this species does not form stacks. The males and females only come together for copulation. The species does not have a pelagic larval phase. The veliger
stage is passed in capsules fixed to the substrate
, and guarded under the shell of the parent. The young hatch as crawling post-veliger larvæ.
, the Black Sea
and the Atlantic Ocean
. These small snails can be found in the littoral and sublittoral zones along sheltered, rocky shores and on muddy or silty areas as long as they can cling to a hard substrate such as stones, living oysters and other shells. The species also occurs on the northern and western coasts of Britain and Ireland, but is absent from the North Sea
and the English Channel
.
Calyptraea chinensis is known in fossil state from the Pliocene
and the Early Pleistocene
.
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
the Chinese hat snail or Chinese hat shell, is a species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of small sea snail
Sea snail
Sea snail is a common name for those snails that normally live in saltwater, marine gastropod molluscs....
, a marine gastropod mollusk in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Calyptraeidae
Calyptraeidae
Calyptraeidae, common name the slipper snails or slipper limpets, cup-and-saucer snails, and Chinese hat snails are a family of small to medium-sized marine prosobranch gastropods...
, the slipper snails or slipper limpets, cup-and-saucer snails, and Chinese hat snails.
Description
The thin shellGastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...
of this species has the shape of an almost symmetrical cone (like a Chinese hat or conical Asian hat), 7 mm high and 15 – 21 mm wide. The internal partition has a spirally curved edge which runs running from the apex
Apex (mollusc)
Apex is an anatomical term for the tip of the mollusc shell of a gastropod, scaphopod, or cephalopod mollusc.-Gastropods:The word "apex" is most often used to mean the tip of the spire of the shell of a gastropod...
to the margin of the shell, and partly covers the aperture
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....
. The presence of this internal shelf distinguishes this species easily from the true limpets. The aperture is round and adapted to the substrate. The shell is creamy white, and glossy on the inside.
Calyptraea chinensis is a filter feeder
Filter feeder
Filter feeders are animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feeding are clams, krill, sponges, baleen whales, and many fish and some sharks. Some birds,...
, binding fine food particles with mucus
Mucus
In vertebrates, mucus is a slippery secretion produced by, and covering, mucous membranes. Mucous fluid is typically produced from mucous cells found in mucous glands. Mucous cells secrete products that are rich in glycoproteins and water. Mucous fluid may also originate from mixed glands, which...
. Like all slipper limpets, this species is a protandrous
Dichogamy
Sequential hermaphroditism is a type of hermaphroditism that occurs in many fish, gastropods and plants. Here, the individual is born one sex and changes sex at some point in their life. They can change from a male to female , or from female to male...
hermaphrodite
Hermaphrodite
In biology, a hermaphrodite is an organism that has reproductive organs normally associated with both male and female sexes.Many taxonomic groups of animals do not have separate sexes. In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which both...
, but the stages of change from male to female have not been clearly defined. Unlike Crepidula fornicata (the American slipper limpet), this species does not form stacks. The males and females only come together for copulation. The species does not have a pelagic larval phase. The veliger
Veliger
A veliger is the planktonic larva of many kinds of marine and freshwater gastropod molluscs, as well as most bivalve mollusks.- Description :...
stage is passed in capsules fixed to the substrate
Substrate (biology)
In biology a substrate is the surface a plant or animal lives upon and grows on. A substrate can include biotic or abiotic materials and animals. For example, encrusting algae that lives on a rock can be substrate for another animal that lives on top of the algae. See also substrate .-External...
, and guarded under the shell of the parent. The young hatch as crawling post-veliger larvæ.
Distribution
Calyptraea chinensis occurs in North-West Africa, in the Mediterranean, the North SeaNorth Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...
, the Black Sea
Black Sea
The Black Sea is bounded by Europe, Anatolia and the Caucasus and is ultimately connected to the Atlantic Ocean via the Mediterranean and the Aegean seas and various straits. The Bosphorus strait connects it to the Sea of Marmara, and the strait of the Dardanelles connects that sea to the Aegean...
and the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
. These small snails can be found in the littoral and sublittoral zones along sheltered, rocky shores and on muddy or silty areas as long as they can cling to a hard substrate such as stones, living oysters and other shells. The species also occurs on the northern and western coasts of Britain and Ireland, but is absent from the North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...
and the English Channel
English Channel
The English Channel , often referred to simply as the Channel, is an arm of the Atlantic Ocean that separates southern England from northern France, and joins the North Sea to the Atlantic. It is about long and varies in width from at its widest to in the Strait of Dover...
.
Calyptraea chinensis is known in fossil state from the Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
and the Early Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
.