Operculum (gastropod)
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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. The shape of the operculum varies greatly from one family of gastropods to another. It is fairly often circular, or more or less oval in shape. In species where the operculum fits snugly, its outline corresponds exactly to the shape of the aperture of the shell and it serves to seal the entrance of the shell. Many families have opercula that are reduced in size, and whi ...
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Lunella (Ninella) Torquata 002
''Lunella'' is a genus of sea snails, marine gastropod mollusks in the family Turbinidae, the turban snails. The Australian Faunal Directory classifies ''Lunella'' as ''Turbo (Lunella)'' Röding, 1798 Species Species within the genus ''Lunella'' include: * ''Lunella cinerea'' (Born, 1778) * '' Lunella coronata'' (Gmelin, 1791) * '' Lunella correensis'' (Récluz, 1853) * '' Lunella granulata'' (Gmelin, 1791) * '' Lunella jungi'' (Lai, 2006) * '' Lunella moniliformis'' Röding, 1798 * '' Lunella ogasawarana'' Tomoyulo Nakano, Kyoko Takashashi & Tomowo Ozawa, 2007 * '' Lunella smaragda'' (Gmelin, 1791) * ''Lunella torquata'' (Gmelin, 1791) * ''Lunella undulata ''Lunella undulata'', common name the common warrener or the lightning turban, is a species of sea snail, marine gastropod mollusk in the family Turbinidae. Description The size of the shell varies between 33 mm and 75 mm. The sol ...'' (Lightfoot, 1786) * '' Lunella viridicallus'' (Jousseaume, 1898) Ref ...
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Amphiboloidea
Amphiboloidea is a taxonomic superfamily of air-breathing land snails. Distribution Amphibolids are found in Indo-Pacific intertidal mangrove, saltmarsh and estuarine mudflat habitats. Taxonomy 2005 taxonomy According to the taxonomy of the Gastropoda (Bouchet & Rocroi, 2005), it is a superfamily in the informal group Basommatophora, within the Pulmonata. This superfamily has contained only one family, the Amphibolidae. 2007 taxonomy Golding et al. (2007)Golding R. E., Ponder W. F. & Byrne M. (2007). "Taxonomy and anatomy of Amphiboloidea (Gastropoda: Heterobranchia: Archaeopulmonata)". ''Zootaxa'' 1476: 1-50abstract have established new families: * Maningrididae Golding, Ponder & Byrne, 2007 - with the only species ''Maningrida arnhemensis'' * Phallomedusidae Golding, Ponder & Byrne, 2007 2010 taxonomy Basommatophora ( Siphonarioidea and Amphiboloidea and Hygrophila) have been found polyphyletic and so Jörger et al. (2010)Jörger K. M., Stöger I., Kano Y., Fuku ...
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Epithelial Cell
Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellular matrix. Epithelial tissues line the outer surfaces of organs and blood vessels throughout the body, as well as the inner surfaces of cavities in many internal organs. An example is the epidermis, the outermost layer of the skin. There are three principal shapes of epithelial cell: squamous (scaly), columnar, and cuboidal. These can be arranged in a singular layer of cells as simple epithelium, either squamous, columnar, or cuboidal, or in layers of two or more cells deep as stratified (layered), or ''compound'', either squamous, columnar or cuboidal. In some tissues, a layer of columnar cells may appear to be stratified due to the placement of the nuclei. This sort of tissue is called pseudostratified. All glands are made up of epith ...
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Buccinum
''Buccinum'' is a genus of medium-sized sea snails, marine gastropod molluscs in the family Buccinidae, the true whelks.Gofas, S.; Bouchet, P. (2014). Buccinum Linnaeus, 1758. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=137701 on 2015-02-18 Snails in this genus are commonly called ''whelks'', a name shared with several related and unrelated species. The common whelk ''Buccinum undatum'' is the most common representative of the genus in the northern Atlantic Ocean. Description The shell is ovate or ovate-conical and elongated. The spire is moderate and pointed. The aperture is oval or oblong with a deep notch anteriorly and without a siphonal canal. The columella is plain, not flattened, swollen above, and often covered with a wide and flattened calcareous callosity, of more diaphanous substance. There sometimes exists a fold at the base of the columella. The outer lip is plain, quite thin, sometimes recurved, ...
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Columella (gastropod)
The columella (meaning "little column") or (in older texts) pillar is a central anatomical feature of a coiled snail shell, a gastropod shell. The columella is often only clearly visible as a structure when the shell is broken, sliced in half vertically, or viewed as an X-ray image. The columella runs from the apex of the shell to the midpoint of the undersurface of the shell, or the tip of the siphonal canal in those shells which have a siphonal canal. If a snail shell is visualized as a cone of shelly material which is wrapped around a central axis, then the columella more or less coincides spatially with the central axis of the shell. In the case of shells that have an umbilicus, the columella is a hollow structure. The columella of some groups of gastropod shells can have a number of plications or folds (the columellar fold, plaits or plicae), which are usually visible when looking to the inner lip into the aperture of the shell. These folds can be wide or narrow, prominen ...
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Bithynia Tentaculata
''Bithynia tentaculata'', common names the mud bithynia or common bithynia, or faucet snailKipp R. M. & Benson A. (2008). ''Bithynia tentaculata''. USGS Nonindigenous Aquatic Species Database, Gainesville, FL. https://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=987 Revision Date: 2/28/2007. is a relatively small species of freshwater snail with gills and an operculum, an aquatic prosobranch gastropod mollusk in the family Bithyniidae. Taxonomy ''Bithynia tentaculata'' is the type species of the genus ''Bithynia''. Forms of ''Bithynia tentaculata'' include: * ''Bithynia tentaculata'' f. ''codia'' * ''Bithynia tentaculata'' f. ''excavata'' * ''Bithynia tentaculata'' f. ''gigas'' * ''Bithynia tentaculata'' f. ''producta'' Menke, 1828 * † ''Bithynia tentaculata tellinii'' Sacco, 1886 The variety † ''Bithynia tentaculata'' var. ''allobrogica'' Fontannes, 1881: synonym of † ''Bithynia minor'' Locard, 1878 Distribution Indigenous distribution The distribution of ''Bithy ...
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Penion Sulcatus Live3
''Penion'' is a genus of large marine snails, commonly known as siphon whelks, classified within the mollusc family Austrosiphonidae, the true whelks.MolluscaBase eds. (2021). MolluscaBase. Penion P. Fischer, 1884. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=488452 on 2021-12-24 Description Siphon whelks are large, benthic marine snails, or whelks. Powell A. W. B., ''New Zealand Mollusca'', William Collins Publishers Ltd, Auckland, New Zealand 1979 Willan, R.C., de C. Cook, S., Spencer, H.G., Creese, R.G., O’Shea, S., Jackson, G.D. Phylum Mollusca. In: de C. Cook, S.C. (eds.), ''New Zealand Coastal Marine Invertebrates 1'', 406 – 407. Canterbury University Press, Christchurch, New Zealand ''Penion'' are commonly called siphon whelks because they have a very long siphon. Species typically have a large, pointed operculum. Ponder, W.F. 1973. A review of the Australian species of ''Penion'' Fischer (Neoga ...
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Predator
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the host) and parasitoidism (which always does, eventually). It is distinct from scavenging on dead prey, though many predators also scavenge; it overlaps with herbivory, as seed predators and destructive frugivores are predators. Predators may actively search for or pursue prey or wait for it, often concealed. When prey is detected, the predator assesses whether to attack it. This may involve ambush or pursuit predation, sometimes after stalking the prey. If the attack is successful, the predator kills the prey, removes any inedible parts like the shell or spines, and eats it. Predators are adapted and often highly specialized for hunting, with acute senses such as vision, hearing, or smell. Many predatory animals, both vertebrate an ...
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Desiccation
Desiccation () is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic (attracts and holds water) substance that induces or sustains such a state in its local vicinity in a moderately sealed container. Industry Desiccation is widely employed in the oil and gas industry. These materials are obtained in a hydrated state, but the water content leads to corrosion or is incompatible with downstream processing. Removal of water is achieved by cryogenic condensation, absorption into glycols, and absorption onto desiccants such as silica gel. Laboratory A desiccator is a heavy glass or plastic container, now somewhat antiquated, used in practical chemistry for drying or keeping small amounts of materials very dry. The material is placed on a shelf, and a drying agent or ''desiccant'', such as dry silica gel or anhydrous sodium hydroxide, is placed below the shelf. Often some sort of humidity indicator is included in the desiccator to sh ...
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Bivalve
Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of marine and freshwater Mollusca, molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bivalves have no head and they lack some usual molluscan organs, like the radula and the odontophore. They include the clams, oysters, Cockle (bivalve), cockles, mussels, scallops, and numerous other family (biology), families that live in saltwater, as well as a number of families that live in freshwater. The majority are filter feeders. The gills have evolved into Ctenidium (mollusc), ctenidia, specialised organs for feeding and breathing. Most bivalves bury themselves in sediment, where they are relatively safe from predation. Others lie on the sea floor or attach themselves to rocks or other hard surfaces. Some bivalves, such as the scallops and file shells, can nekton, swim. The shipworms bore into wood, clay, or ...
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Valve (mollusc)
A valve is each articulating part of the shell of a mollusc or another multi-shelled animal such as brachiopods and some crustaceans. Each part is known as a valve or in the case of chitons, a "plate". Members of two classes of molluscs, the Bivalvia (clams) and the Polyplacophora (chitons), have valves. Species within one family of very unusual small sea snails, marine opisthobranch gastropods in the family Juliidae, also have two articulating shells or valves, which resemble those of a bivalve. This exceptional family is commonly known as the bivalved gastropods. Gastropods in general are sometimes called "univalves", because in those that have a shell, the shell is usually in one part. Chitons The valves of chitons are eight dorsal, articulated shell plates, which are frequently coloured and sculpted. After death the girdle that holds the plates together disintegrates and the plates separate. Thus individual plates can be found washed up in beach drift, as shown in t ...
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Aptychus
An aptychus is a type of marine fossil. It is a hard anatomical structure, a sort of curved shelly plate, now understood to be part of the body of an ammonite. Paired aptychi have, on rare occasions, been found at or within the aperture of ammonite shells. The aptychus was usually composed of calcite, whereas the ammonite shell was aragonite. Aptychi can be found well-preserved as fossils, but usually quite separate from ammonite shells. This circumstance led to them being initially classified as valves of bivalves (clams), which they do somewhat resemble. Aptychi are found in rocks from the Devonian period through to those of the Cretaceous period. There are many forms of aptychus, varying in shape and in the sculpture of the inner and outer surfaces. However, because they are so rarely found in position within the ammonite shell, it is often unclear which kind of aptychus belonged to which species of ammonite. When only a single plate is present, as is sometimes the case, ...
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