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Pachychilus Laevisimus
''Pachychilus laevissimus'' is a species of freshwater snail with an operculum, an aquatic gastropod mollusk in the family Pachychilidae. Distribution This species occurs in Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th .... References External links laevisimus Gastropods described in 1824 Molluscs of Venezuela {{Pachychilidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastropod Shell
The gastropod shell is part of the body of a Gastropoda, gastropod or snail, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium storage. Some gastropods appear shell-less (slugs) but may have a remnant within the mantle, or in some cases the shell is reduced such that the body cannot be retracted within it (semi-slug). Some snails also possess an operculum that seals the opening of the shell, known as the Aperture (mollusc), aperture, which provides further protection. The study of mollusc shells is known as conchology. The biological study of gastropods, and other molluscs in general, is malacology. Shell morphology terms vary by species group. Shell layers The gastropod shell has three major layers secreted by the Mantle (mollusc), mantle. The calcareous central layer, tracum, is typically made of calcium carbonate precipitated into an organic matrix known as c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Brettingham Sowerby I
George Brettingham Sowerby I (12 August 1788 – 26 July 1854) was a British naturalist, illustrator and conchologist. Life He was the second son of James Sowerby. George was educated at home under private tutors, and afterwards assisted his father in the production of illustrated works on natural history. On the latter's death in 1822, he and his brother James De Carle Sowerby continued their father's work on fossil shells, publishing the latter parts of the ''Mineral Conchology of Great Britain''. He published about 50 papers on molluscs and started several comprehensive, illustrated books on the subject, the most important the ''Thesaurus Conchyliorum'', a work that was continued by his son, George Brettingham Sowerby II and his grandson George Brettingham Sowerby III. One of his first works was the cataloguing of the collection of the Earl of Tankerville. He also dealt in shells and natural history objects, his place of business being first in King Street, Covent Garden, ... [...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] |
Freshwater Snail
Freshwater snails are gastropod mollusks which live in fresh water. There are many different families. They are found throughout the world in various habitats, ranging from ephemeral pools to the largest lakes, and from small seeps and springs to major rivers. The great majority of freshwater gastropods have a shell, with very few exceptions. Some groups of snails that live in freshwater respire using gills, whereas other groups need to reach the surface to breathe air. In addition, some are amphibious and have both gills and a lung (e.g. ''Ampullariidae''). Most feed on algae, but many are detritivores and some are filter feeders. According to a 2008 review of the taxonomy, there are about 4,000 species of freshwater gastropods (3,795–3,972). At least 33–38 independent lineages of gastropods have successfully colonized freshwater environments. It is not possible to quantify the exact number of these lineages yet, because they have yet to be clarified within the Cerit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 which a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquatic Animal
An aquatic animal is any animal, whether invertebrate or vertebrate, that lives in water for most or all of its lifetime. Many insects such as mosquitoes, mayflies, dragonflies and caddisflies have aquatic larvae, with winged adults. Aquatic animals may breathe air or extract oxygen from water through specialised organs called gills, or directly through the skin. Natural environments and the animals that live in them can be categorized as aquatic (water) or terrestrial (land). This designation is polyphyletic. Description The term aquatic can be applied to animals that live in either fresh water or salt water. However, the adjective marine is most commonly used for animals that live in saltwater, i.e. in oceans, seas, etc. Aquatic animals (especially freshwater animals) are often of special concern to conservationists because of the fragility of their environments. Aquatic animals are subject to pressure from overfishing, destructive fishing, marine pollution, hunting, and cli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastropod
The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. There are many thousands of species of sea snails and slugs, as well as freshwater snails, freshwater limpets, and land snails and slugs. The class Gastropoda contains a vast total of named species, second only to the insects in overall number. The fossil history of this class goes back to the Late Cambrian. , 721 families of gastropods are known, of which 245 are extinct and appear only in the fossil record, while 476 are currently extant with or without a fossil record. Gastropoda (previously known as univalves and sometimes spelled "Gasteropoda") are a major part of the phylum Mollusca, and are the most highly diversified class in the phylum, with 65,000 to 80,000 living snail and slug species. The anatomy, behavior, feeding, and re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusk
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known invertebrate species. The gas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pachychilidae
Pachychilidae, common name pachychilids, is a taxonomic family of freshwater snails, gastropod molluscs in the clade Sorbeoconcha.Gofas, S. (2014). Pachychilidae. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=411651 on 2014-11-20 Distribution Pachychilids are freshwater snails with a worldwide distribution in the tropics. Representatives are found in South and Central America, Africa, Madagascar, South and South-east Asia and tropical Australia (Queensland: Torres Strait Islands). Description Pachychilids have an operculum, which is concentric and multispiral. Ecology All species in the family inhabit freshwater except '' Faunus ater'', which is a brackish water snail found in estuaries and other coastal habitats. Pachychilids are either oviparous (lay eggs), ovoviviparous or viviparous (retain developing eggs and youngs in special incubatory structures). Notes on the taxonomy The name is derived from a co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Non-marine Molluscs Of Venezuela
The non-marine molluscs of Venezuela are a part of the molluscan fauna of Venezuela (which is part of the wildlife of Venezuela). Non-marine molluscs are the snails, clams and mussels that live in freshwater habitats, and the snails and slugs that live on land. Sea-dwelling molluscs are not included in this list. A number of species of non-marine molluscs are found in the wild in Venezuela. Historical background Studies on the knowledge of the Venezuelan malacofauna begin in the nineteenth century with the work of German malacologist Eduard von Martens around 1873 who published the first list of the mollusks Venezuela. Three years later the German-Venezuelan Adolfo Ernst, taking as its starting point and extending Martens list, published a second list in 1876. Subsequent to these two pioneering nineteenth century works, only sporadic descriptions were published in foreign publications. It took about half a century for new listings of malacofauna of Venezuela to be published, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pachychilus
''Pachychilus'', common name the jute snails, is a genus of freshwater snails with an operculum, aquatic gastropod mollusk in the family Pachychilidae. ''Pachychilus'' is the type genus of the family Pachychilidae. Distribution The distribution of species in the genus ''Pachychilus'' includes: * Cuba (2 species), Venezuela, Belize, Mexico, and others. Species Species within the genus ''Pachychilus'' include: * † ''Pachychilus anagrammatus'' Dall, 1913 * ''Pachychilus apheles'' F. G. Thompson, 1967 * ''Pachychilus apis'' (I. Lea & H. C. Lea, 1851) * ''Pachychilus atratus'' Pilsbry & Hinkley, 1910 * † ''Pachychilus caboblanquensis'' Weisbord, 1962 * † ''Pachychilus cancelloides'' (Aldrich, 1911) * † ''Pachychilus canoasensis'' Olsson, 1931 * ''Pachychilus chrysalis'' (Brot, 1872) * ''Pachychilus cinereus'' (Morelet, 1849) * ''Pachychilus conicus'' (d'Orbigny, 1842) * ''Pachychilus corpulentus'' F. G. Thompson, 1967 * '' Pachychilus corvinus'' (Morelet, 1849) * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastropods Described In 1824
The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. There are many thousands of species of sea snails and slugs, as well as freshwater snails, freshwater limpets, and land snails and slugs. The class Gastropoda contains a vast total of named species, second only to the insects in overall number. The fossil history of this class goes back to the Late Cambrian. , 721 families of gastropods are known, of which 245 are extinct and appear only in the fossil record, while 476 are currently extant with or without a fossil record. Gastropoda (previously known as univalves and sometimes spelled "Gasteropoda") are a major part of the phylum Mollusca, and are the most highly diversified class in the phylum, with 65,000 to 80,000 living snail and slug species. The anatomy, behavior, feeding, and reproduct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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