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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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicella Obvia1
''Helicella'' is a genus of small to medium-sized, air-breathing land snails, terrestrial pulmonate gastropod mollusks in the subfamily Helicellinae of the family Geomitridae, the hairy snails and their allies. MolluscaBase eds. (2021). MolluscaBase. Helicella A. Férussac, 1821. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=153980 on 2021-02-01 Species Species within the genus ''Helicella'' include: , accessed 29 June 2010. * '' Helicella bolenensis'' < ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of Taxonomy (biology), 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 reproduction, produce Fertility, fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology (biology), 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 binomial nomenclature, 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 specifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nautilus Umbilicus- Allonautilus Scrobiculatus
The nautilus (, ) is a pelagic marine mollusc of the cephalopod family Nautilidae. The nautilus is the sole extant family of the superfamily Nautilaceae and of its smaller but near equal suborder, Nautilina. It comprises six living species in two genera, the type of which is the genus ''Nautilus''. Though it more specifically refers to species ''Nautilus pompilius'', the name chambered nautilus is also used for any of the Nautilidae. All are protected under CITES Appendix II. Depending on species, adult shell diameter is between 4 and 10 inches. Nautilidae, both extant and extinct, are characterized by involute or more or less convolute shells that are generally smooth, with compressed or depressed whorl sections, straight to sinuous sutures, and a tubular, generally central siphuncle.Kümmel, B. 1964. Nautiloidae-Nautilida, in the Treatise on Invertebrate Paleontology, Geological Society of America and Univ of Kansas Press, Teichert and Moore eds. Having survived relatively un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1212amma
1 (one, unit, unity) is a number representing a single or the only entity. 1 is also a numerical digit and represents a single unit of counting or measurement. For example, a line segment of ''unit length'' is a line segment of length 1. In conventions of sign where zero is considered neither positive nor negative, 1 is the first and smallest positive integer. It is also sometimes considered the first of the infinite sequence of natural numbers, followed by 2, although by other definitions 1 is the second natural number, following 0. The fundamental mathematical property of 1 is to be a multiplicative identity, meaning that any number multiplied by 1 equals the same number. Most if not all properties of 1 can be deduced from this. In advanced mathematics, a multiplicative identity is often denoted 1, even if it is not a number. 1 is by convention not considered a prime number; this was not universally accepted until the mid-20th century. Additionally, 1 is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neverita Josephinia 000
''Neverita'' is a genus of medium-sized to large sea snails, marine gastropod molluscs in the subfamily Polinicinae of the family Naticidae, the moon snails Bouchet, P.; Gofas, S. (2012). Neverita. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=138241 on 2012-07-12 The type species of this genus is '' Neverita josephinia'' Risso, 1826. Species Species within the genus ''Neverita'' include: * † '' Neverita amerrukensis'' Pacaud & Lebrun, 2019 * '' Neverita aulacoglossa'' (Pilsbry & Vanatta, 1909) * '' Neverita delessertiana'' ( Recluz in Chenu, 1843) Huelsken T. et al. 2006''Neverita delessertiana (Recluz in Chenu, 1843): a naticid species (Gastropoda: Caenogastropoda) distinct from Neverita duplicata (Say, 1822) based on molecular data, morphological characters, and geographical distribution'' Zootaxa, 1257:1-25. * '' Neverita didyma'' (Röding, 1798) * '' ''Neverita duplicata'''' ( Say, 1822) * '' Neverita j ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cittarium Pica Umbilicus
''Cittarium'' is a genus of a sea snails, a marine gastropod mollusk in the family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ... Tegulidae.Rosenberg, G. (2013). Cittarium Philippi, 1847. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=413476 on 2013-12-10 Species There are two species in the genus ''Cittarium'': * † '' Cittarium maestratii'' Lozouet, 2002 * '' Cittarium pica'' (Linnaeus, 1758) References * Williams S.T., Karube S. & Ozawa T. (2008) ''Molecular systematics of Vetigastropoda: Trochidae, Turbinidae and Trochoidea redefined.'' Zoologica Scripta 37: 483–506. External links Philippi, R. A. (1847). Versuch einer systematischen Eintheilung des Geschlechtes Trochus. Zeitschrift für Malakozoologie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discus Rotundatus
''Discus rotundatus'', common name rotund disc, is a species of small, air-breathing, land snail, a terrestrial pulmonate gastropod mollusk in the family Discidae, the disk snails. Description The shells of ''Discus rotundatus'' in the adult stage measure in diameter and in height. Shells are reddish brown with darker cross bands, flat and densely ribbed. The umbilicus is quite wide, reaching about 1/3 of the shell diameter. Among the species of ''Discus'' in Europe and North America, ''Discus rotundatus'' is recognized by the alternating pattern of reddish brown spots, tight coiling of the whorls and broad and shallow umbilicus. The body of this gastropod is bluish black on the upperside, while the lower side is greyish white. They mainly feed on plant debris, humus, algae and fungi. Cycle of life These snails, like most terrestrial gastropods, are hermaphrodite. The reproductive season last from May to October. Usually they lay 20-50 eggs in rotting wood or below decay ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petasina Unidentata
''Petasina unidentata'' is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Hygromiidae Hygromiidae is a taxonomic family of small to medium-sized air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Helicoidea. Helicellidae Ihering, 1909 Anatomy Some snails in genera within this family create a ..., the hairy snails and their allies. Shell description File:Petasina unidentata shell 2.jpg, apical view File:Petasina unidentata shell.jpg, apertural view File:Petasina unidentata shell 3.jpg, basal view References Petasina Gastropods described in 1805 {{Hygromiidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicella Itala
''Helicella itala'' is a species of medium-sized, air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Geomitridae, the hairy snails and their allies. MolluscaBase eds. (2021). MolluscaBase. Helicella itala (Linnaeus, 1758). Accessed through: World Register of Marine Species at: http://marinespecies.org/aphia.php?p=taxdetails&id=426387 on 2021-02-01 English common name is Heath snail. ;Subspecies: * ''Helicella itala itala'' (Linnaeus, 1758) * ''Helicella itala pampelonensis'' (A. Schmidt, 1855) Life cycle The size of the egg is 1.5 mm.Heller J.: ''Life History Strategies''. in Barker G. M. (ed.): The biology of terrestrial molluscs'. CABI Publishing, Oxon, UK, 2001, . 1-146, cited page: 428. This species of snail makes and uses love darts during mating. Description The 12–20 mm. shell is broad and very depressed with an open coil forming a convex, low spire. The umbilicus is very wide. The whorls are slightly convex and have sha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columella (mollusc)
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] |
Mollusc Shell
The mollusc (or molluskOften spelled mollusk shell in the USA; the spelling "mollusc" are preferred by ) shell is typically a calcareous exoskeleton which encloses, supports and protects the soft parts of an animal in the phylum Mollusca, which includes snails, clams, tusk shells, and several other classes. Not all shelled molluscs live in the sea; many live on the land and in freshwater. The ancestral mollusc is thought to have had a shell, but this has subsequently been lost or reduced on some families, such as the squid, octopus, and some smaller groups such as the caudofoveata and neomeniomorpha, solenogastres. Today, over 100,000 living species bear a shell; there is some dispute as to whether these shell-bearing molluscs form a monophyletic group (conchifera) or whether shell-less molluscs are interleaved into their family tree. Malacology, the scientific study of molluscs as living organisms, has a branch devoted to the study of shells, and this is called conchology—al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columella (mollusc)
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] |
