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Alvania Kwandangensis
''Alvania kwandangensis'' is a species of small sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae.MolluscaBase eds. (2024). MolluscaBase. Alvania kwandangensis (Schepman, 1909). Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=1617832 on 2024-01-24 Description The length of the shell attains 2.5 mm, its diameter 1.25 mm. (Original description) The small, conic-oval shell is solid and opaque. It contains about 6, slightly convex, whorls, separated by a deep suture. The colour of the shell is whitish, with spiral rows of purple-brown spots. The whorls of the protoconch are smooth. The sculpture of the subsequent whorls consists of rather thin, straight ribs, about 18 on the body whorl. They are crossed by spiral ridges, of which there are 6 on the penultimate whorl and 11 on the last one, the sixth running just in a channel above the suture. This sculpture renders the shell cancell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mattheus Marinus Schepman
Mattheus Marinus Schepman (17 August 1847 – 19 November 1919) was a Dutch malacologist. He was one of the foremost collectors of mollusc shells in the Netherlands, and was also high on the overall list of European collectors. Dutch collectors developed an interest in natural history specimens that were collected on worldwide expeditions since the 16th century. An interest in conchology led to numerous shell publications. In 1934 the Nederlandse Malacologische Vereniging (Netherlands Malacological Society) was founded. In commemoration of its 75th anniversary, a book honoring in detail the work of Mattheus Schepman was published. His research Schepman was both a collector and a methodical scientist, which combination "made his collection of great value to the entire malacological community." He was given the opportunity to study a collection by Max Carl Wilhelm Weber, Director of the Zoölogisch Museum Amsterdam (ZMA). Many of the specimens he studied and collected were gathe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protoconch
A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also called "nucleus". The protoconch may sometimes consist of several whorl (mollusc), whorls, but when this is the case, the whorls show no growth lines. The whorls of the adult shell, which are formed after the protoconch, are known as the teleoconch. The teleoconch starts forming when the larval gastropod becomes a juvenile, and the protoconch may dissolve. Quite often there is a visible line of demarcation where the protoconch ends and the teleoconch begins, and there may be a noticeable change in Sculpture (mollusc), sculpture, or a sudden appearance of sculpture at that point. In some gastropod groups (such as the Architectonicidae), the teleoconch whorls spiral in the opposite direction to the protoconch. In those cases, the shell is called ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulawesi
Sulawesi ( ), also known as Celebes ( ), is an island in Indonesia. One of the four Greater Sunda Islands, and the List of islands by area, world's 11th-largest island, it is situated east of Borneo, west of the Maluku Islands, and south of Mindanao and the Sulu Archipelago. Within Indonesia, only Sumatra, Borneo, and New Guinea, Papua are larger in territory, and only Java and Sumatra are more populous. The landmass of Sulawesi includes four peninsulas: the northern Minahasa Peninsula, the East Peninsula, Sulawesi, East Peninsula, the South Peninsula, Sulawesi, South Peninsula, and the Southeast Peninsula, Sulawesi, Southeast Peninsula. Three gulfs separate these peninsulas: the Gulf of Tomini between the northern Minahasa and East peninsulas, the Tolo Gulf between the East and Southeast peninsulas, and the Bone Gulf between the South and Southeast peninsulas. The Strait of Makassar runs along the western side of the island and separates the island from Borneo. Etymology The n ... [...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 (mollusc), 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 (mollusc), aperture of the shell. These ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Varix (mollusc)
A varix (: varices) is an anatomical feature of the gastropod shell, shell of certain sea snails, marine (ocean), marine gastropod molluscs. Gastropods whose shells have varices are primarily families and species within the Taxonomy (biology), taxonomic groups Littorinimorpha and Neogastropoda. The varix is a thickened axial ridge, a subcylindrical protrusion, in the Exoskeleton, shell which exists in some families of marine gastropods. It is an important shell character in generic classification. A varix is located at intervals around the Whorl (mollusc), whorl, and is formed by considerable thickening of the outer lip during a resting stage in the growth of the shell. In other words, in gastropods whose shells have varices, the shells are characterised by episodic growth - the shell grows in spurts, and during the resting phase the varix forms. In many gastropod whose shells have varices, for example the Cassinae, the varix is essentially merely a thickening and swelling of ... [...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 (bivalve), 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 (mollusc), apex of the shell is called an orifice, and in the Haliotidae (abalone) where the row of respiratory openings in the shell are also called orifices. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Body Whorl
The body whorl is part of the morphology (biology), morphology of the gastropod shell, 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 (mollusc), whorl (or revolution) of a spiral or Helix, helical Gastropod shell, shell, terminating in the Aperture (mollusc), 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 Spire (mollusc), spired. The shell of the abalone is a good example of this kind of shell. The opposite ... [...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 sculp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral or whorled 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 Cone (geometry), conical tube, the growth of which is coiled into an overall Helix, 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 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
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. It is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. Other ways of defining species include their karyotype, DNA sequence, morphology (biology), morphology, behaviour, or ecological niche. In addition, palaeontologists 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. About 14% of these had been described by 2011. All species (except viruses) are given a binomial nomenclature, two-part name, a "binomen". The first part of a binomen is the name of a genus to which the species belongs. The second part is called the specific name (zoology), specific name or the specific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rissoidae
Rissoidae is a large family of sea snails. Members of the Rissoidae are very small in size and possess an operculum. Distribution and habitat Rissoidae are found worldwide. They live on sandy or gravel bottoms among algae or marine plants. They are also found under rocks in crevices or other sheltered places. Subfamilies The following subfamilies were recognized in the taxonomy of Bouchet & Rocroi of 2005: * Rissoinae Gray, 1847 * Rissoininae Stimpson, 1865 In 2013 the subfamily Rissoininae was elevated to the rank of family Rissoinidae by Criscione F. & Ponder W.F. Genera Genera within Rissoidae include: Powell A. W. B., ''New Zealand Mollusca'', William Collins Publishers Ltd, Auckland, New Zealand 1979 * '' Alvania'' Risso, 1826 * '' Amphirissoa'' Dautzenberg & Fischer, 1897 * '' Archaschenia'' Zhgenti, 1981 † * '' Benthonella'' Dall, 1889 * '' Benthonellania'' Lozouet, 1990 * '' Boreocingula'' Golikov and Kussakin, 1974 * '' Boreomica'' Guzhov, 2017 † * '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family (, : ) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". The delineation of what constitutes a family—or whether a described family should be acknowledged—is established and decided upon by active taxonomists. There are not strict regulations for outlining or acknowledging a family, yet in the realm of plants, these classifications often rely on both the vegetative and reproductive characteristics of plant species. Taxonomists frequently hold varying perspectives on these descriptions, leading to a lack of widespread consensus within the scientific community ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
