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Seguenzia Dautzenbergi
''Seguenzia dautzenbergi'' is a species of extremely small deep water sea snail, a marine gastropod mollusk in the family Seguenziidae.WoRMS (2013). ''Seguenzia dautzenbergi'' Schepman, 1909. Retrieved through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=492448 on 2013-06-10 Description (Original description by M. Schepman) The height of this whitish-yellow shell attains 4¼ mm. The rather small, umbilicate shell has a spire forming a short gradated cone. The shell contains 7 whorls of which the uppermost forms the smooth nucleus, followed by about 2 whorls with a submedian keel and displaying a cancellated appearance by the intercrossing of subequal spiral and radiating riblets. The other whorls have each 3 spirals, of which the uppermost runs at a little distance from the suture. The next one is the strongest. It renders the whorls carinate about halfway, and a third which seems to run just in the rather conspicuous suture. M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sculpture (mollusc)
Sculpture is a feature of many of the shells of mollusks. It is three-dimensional ornamentation on the outer surface of the shell, as distinct from either the basic shape of the shell itself or the pattern of colouration, if any. Sculpture is a feature found in the shells of gastropods, bivalves, and scaphopods. The word "sculpture" is also applied to surface features of the aptychus of ammonites, and to the outer surface of some calcareous opercula of marine gastropods such as some species in the family Trochidae. Sculpture can be concave or convex, incised into the surface or raised from it. Sometimes the sculpture has microscopic detailing. The term "sculpture" refers only to the calcareous outer layer of shell, and does not include the proteinaceous periostracum, which is in some cases textured even when the underlying shell surface is smooth. In many taxa, there is no sculpture on the shell surface at all, apart from the presence of fine growth lines. The sculpture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceram Sea
The Seram Sea or Ceram Sea ( id, Laut Seram) is one of several small seas between the scattered islands of Indonesia. It is a section of the Pacific Ocean with an area of approximately located between Buru and Seram, which are two of the islands once called the South Moluccas. These islands are the native habitat of plants long coveted for their use as spices, such as nutmeg, cloves, and black peppercorns, and the seas surrounding them were busy shipping routes. The Seram Sea is also the habitat of several species of tropical goby and many other fish. Like many other small Indonesian seas, the Seram Sea is rocky and very tectonically active. Extent The International Hydrographic Organization (IHO) defines the Seram Sea as being one of the waters of the East Indian Archipelago. The IHO defines its limits as follows: ''On the North and Northeast.'' A line from Tanjong Dehekolano, the Eastern extreme of the Soela Sula.html"_;"title="Sula_Islands.html"_;"title="/nowiki>Sula_Isla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Banda Sea
The Banda Sea ( id, Laut Banda, pt, Mar de Banda, tet, Tasi Banda) is one of four seas that surround the Maluku Islands of Indonesia, connected to the Pacific Ocean, but surrounded by hundreds of islands, including Timor, as well as the Halmahera and Ceram Seas. It is about 1000 km (600 mi) east to west, and about 500 km (300 mi) north to south. Extent The International Hydrographic Organization (IHO) defines the Banda Sea as being one of the waters of the East Indian Archipelago. The IHO defines its limits as follows: ''On the North'' The Southern limits of the Molukka Sea and the Western and Southern limits of the Ceram Sea. ''On the East.'' From Tg Borang, the Northern point of Noehoe Tjoet Kai_Besar">/nowiki>Kai_Besar.html" ;"title="Kai_Besar.html" ;"title="/nowiki>Kai Besar">/nowiki>Kai Besar">Kai_Besar.html" ;"title="/nowiki>Kai Besar">/nowiki>Kai Besar/nowiki>, through this island to its Southern point, thence a line to the Northeast point of F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Makassar Strait
Makassar Strait is a strait between the islands of Borneo and Sulawesi in Indonesia. To the north it joins the Celebes Sea, while to the south it meets the Java Sea. To the northeast, it forms the Sangkulirang Bay south of the Mangkalihat Peninsula. The strait is an important regional shipping route in Southeast Asia. The Mahakam River and Karangan River of Borneo empty into the strait. Ports along the strait include Balikpapan and Bontang in Borneo, and Makassar, Palu, and Parepare in Sulawesi. The city of Samarinda is 48 km (30 mi) from the strait, along the Mahakam. Extent The International Hydrographic Organization (IHO) defines the Makassar Strait as being one of the waters of the East Indian Archipelago. The IHO defines its limits as follows: The channel between the East coast of Borneo and the West coast of Celebes _Sulawesi.html" ;"title="/nowiki> Sulawesi">/nowiki> Sulawesi/nowiki>, is bounded: ''On the North.'' By a line joining Tanjong Mangkalih ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where the head-foot part of the body of the animal emerges for locomotion, feeding, etc. The term ''aperture'' is used for the main opening in gastropod shells, scaphopod shells, and also for ''Nautilus'' and ammonite shells. The word is not used to describe bivalve shells, where a natural opening between the two shell valves in the closed position is usually called a ''gape''. Scaphopod shells are tubular, and thus they have two openings: a main anterior aperture and a smaller posterior aperture. As well as the aperture, some gastropod shells have additional openings in their shells for respiration; this is the case in some Fissurellidae (keyhole limpets) where the central smaller opening at the apex of the shell is called an orifice, and in the Haliotidae (abalones) where the row of respiratory openings in the shell are also called orifices. In gastropods In some prosobranch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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, prominent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Umbilicus (mollusc)
The umbilicus of a shell is the axially aligned, hollow cone-shaped space within the whorls of a coiled mollusc shell. The term umbilicus is often used in descriptions of gastropod shells, i.e. it is a feature present on the ventral (or under) side of many (but not all) snail shells, including some species of sea snails, land snails, and freshwater snails. The word is also applied to the depressed central area on the planispiral coiled shells of ''Nautilus'' species and fossil ammonites. (These are not gastropods, but shelled cephalopods.) In gastropods The spirally coiled whorls of gastropod shells frequently connect to each other by their inner sides, during the natural course of its formation. This results in a more or less solid central axial pillar, known as the columella. The more intimate the contact between the concave side of the whorls is, the more solid the columella becomes. On the other hand, if this connection is less intense, a hollow space inside the whorls may re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Body Whorl
The body whorl is part of the morphology of the shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk. In gastropods In gastropods, the body whorl, or last whorl, is the most recently formed and largest whorl (or revolution) of a spiral or helical shell, terminating in the aperture. It is called the "body whorl" because most of the body of the soft parts of the animal fits into this whorl. The proportional size of the body whorl in gastropod shells differs greatly according to the actual shell morphology. For shells in which the rate of whorl expansion of each revolution around the axis is very high, the aperture and the body whorl are large, and the shell tends to be low spired. The shell of the abalone is a good example of this kind of shell. The opposite tendency can sometimes create a high spire with very little whorl increase per revolution. In these instances, e.g. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suture (anatomy)
In anatomy, a suture is a fairly rigid joint between two or more hard elements of an organism, with or without significant overlap of the elements. Sutures are found in the skeletons or exoskeletons of a wide range of animals, in both invertebrates and vertebrates. Sutures are found in animals with hard parts from the Cambrian period to the present day. Sutures were and are formed by several different methods, and they exist between hard parts that are made from several different materials. Vertebrate skeletons The skeletons of vertebrate animals (fish, amphibians, reptiles, birds, and mammals) are made of bone, in which the main rigid ingredient is calcium phosphate. Cranial sutures The skulls of most vertebrates consist of sets of bony plates held together by cranial sutures. These sutures are held together mainly by Sharpey's fibers which grow from each bone into the adjoining one. Sutures in the ankles of land vertebrates In the type of crurotarsal ankle which is found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Snail
Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the absence of a visible shell. Definition Determining whether some gastropods should be called sea snails is not always easy. Some species that live in brackish water (such as certain neritids) can be listed as either freshwater snails or marine snails, and some species that live at or just above the high tide level (for example species in the genus '' Truncatella'') are sometimes considered to be sea snails and sometimes listed as land snails. Anatomy Sea snails are a very large group of animals and a very diverse one. Most snails that live in salt water respire using a gill or gills; a few species, though, have a lung, are intertidal, and are active only at low tide when they can move around in the air. These air-breathing species includ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whorl (mollusc)
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. A spiral shell can be visualized as consisting of a long conical tube, the growth of which is coiled into an overall helical or planispiral shape, for reasons of both strength and compactness. The number of whorls which exist in an adult shell of a particular species depends on mathematical factors in the geometric growth, as described in D'Arcy Wentworth Thompson's classic 1917 book ''On Growth and Form'', and by David Raup. The main factor is how rapidly the conical tube expands (or flares-out) over time. When the rate of expansion is low, such that each subsequent whorl is not that much wider than the previous one, then the adult shell has numerous whorls. When the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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