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Sphaerium Nucleus
''Sphaerium nucleus'' is a freshwater bivalve of the family Sphaeriidae. It has been often confused with ''Sphaerium corneum'' and is consequently quite poorly known. Description ''Sphaerium nucleus'' is a very small bivalve which may grow up to 8mm in width and length. It differs from ''Sphaerium corneum'' only in details. Like almost all bivalves, it is a filter-feeder. Taxonomy ''Sphaerium nucleus'' was described by Studer 1820, who placed it in the genus ''Cyclas''. It was later thought to be a subspecies of ''Sphaerium corneum''. Subsequently it was raised to a full species again as ''Sphaerium nucleus'' (Studer, 1820) due to its having a different form of kidney, and the shell having a broad hinge plate, dense porosity and more tumid shells with broad umbones. Unlike ''S. corneum'' it has a preference for temporary habitats. Distribution ''S. nucleus'' occurs widely in Europe, from Spain to Ukraine. It appears to be absent from Russia. * Austria * Britain and Ireland (b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Samuel Emanuel Studer
Samuel Emanuel Studer (1757–1834) was a Swiss malacologist. He named various taxa of molluscs including: * The land snail genus ''Pomatias ''Pomatias'' is a genus of small operculate land snails, terrestrial gastropod mollusks in the family Pomatiidae. MolluscaBase eds. (2022). MolluscaBase. Pomatias S. Studer, 1789. Accessed through: World Register of Marine Species at: https://m ...'' Studer, 1789 Works *Studer, S. 1820. Kurzes Verzeichniss der bis jetzt in unserm Vaterlande entdeckten Conchylien.'' Naturwissenschaftlicher Anzeiger der Allgemeinen Schweizerischen Gesellschaft für die Gesammten Naturwissenschaften'' 3 (11): 83-90, 91-94. Bern. *contributions to Coxe, W, 1789. ''Travels in Switzerland, in a series of letters to William Melmoth, Esq''. In three volumes. Vol. III. - pp. I-VIII 1-8 I-IV 1-4 1-446. London. (Cadell). References * 2,400 years of Malacology at Further reading * L. Forcart, 1957. Ipsa Studeri Conchylia. ''Professor Samuel Studer (1757-1834), se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bivalve
Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater 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, cockles, mussels, scallops, and numerous other 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 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 swim. The shipworms bore into wood, clay, or stone and live inside these substances. The shell of a bivalve is composed of calc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') 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". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphaeriidae
Sphaeriidae is a family of small to minute freshwater bivalve molluscs in the order Sphaeriida. In the US, they are commonly known as pea clams or fingernail clams. Heard, William H. 1977. Reproduction of fingernail clams (Sphaeriidae: ''Sphaerium'' and ''Musculium''). Malacologia, 16: 421-455. Genera Genera: * Euperinae ** '' Byssanodonta'' d'Orbigny, 1846 ** ''Eupera'' Bourguignat, 1854 * Sphaeriinae ** ''Afropisidium'' Kuiper, 1962 ** ''Euglesa'' Jenyns, 1832 ** ''Musculium'' Link, 1807 ** '' Odhneripisidium'' Kuiper, 1962 ** ''Pisidium'' C. Pfeiffer, 1821 ** ''Sphaerium'' Scopoli, 1777 * fossils ** †'' Megasphaerioides'' Komatsu, J.-H. Chen & Q.-F. Wang, 2003 ** †'' Protosphaerium'' Hocknull, 2000 ** †'' Sphaericoncha'' Kolesnikov, 1980 Biology and ecology Sphaeriidae are hermaphrodites with internal fertilization. Developing young are incubated within their mother (ovoviviparity), and newborn clams look like miniature copies of the adults. Parasites and/or predat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphaerium Corneum
''Sphaerium corneum'', also known as the European fingernailclam, is a very small freshwater clam, an aquatic bivalve mollusk in the family Sphaeriidae, the fingernail clams. Description The shell is fairly globular and can grow up to 9–13.5 mm in size. The color of the shell is usually a brown to gray with the juveniles being a yellow color. Their shells exhibit striae, thin parallel rows of elevated lines. Revisiondate: 3/23/2007 Ecology These small clams are found in shallow, freshwater habitats with slow moving waters, including freshwater lakes, rivers and creeks. As with most bivalves, ''Sphaerium corneum'' is mainly a filter feeder and thus prefers more eutrophic waters that provide a greater food source. These clams have exhibited a unique ability to climb up plants and structures around their habitat to find more optimal locations for feeding. They also are known to deposit feed in times of low current or food availability. This species has shown a preference ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species have subspecies, but for those that do there must be at least two. Subspecies is abbreviated subsp. or ssp. and the singular and plural forms are the same ("the subspecies is" or "the subspecies are"). In zoology, under the International Code of Zoological Nomenclature, the subspecies is the only taxonomic rank below that of species that can receive a name. In botany and mycology, under the International Code of Nomenclature for algae, fungi, and plants, other infraspecific ranks, such as variety, may be named. In bacteriology and virology, under standard bacterial nomenclature and virus nomenclature, there are recommendations but not strict requirements for recognizing other important infraspecific ranks. A taxonomist decides whether ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species Problem
The species problem is the set of questions that arises when biologists attempt to define what a species is. Such a definition is called a species concept; there are at least 26 recognized species concepts. A species concept that works well for sexually reproducing organisms such as birds may be useless for species that reproduce asexually, such as bacteria. The scientific study of the species problem has been called microtaxonomy. One common, but sometimes difficult, question is how best to decide which species an organism belongs to, because reproductively isolated groups may not be readily recognizable, and cryptic species may be present. There is a continuum from ''reproductive isolation'' with no interbreeding, to ''panmixis'', unlimited interbreeding. Populations can move forward or backwards along this continuum, at any point meeting the criteria for one or another species concept, and failing others. Many of the debates on species touch on philosophical issues, such as no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Non-marine Molluscs Of The Czech Republic
This is a list of the non-marine molluscs of the Czech Republic. That country is land-locked and therefore it has no marine molluscs, only land and freshwater species, including snails, slugs, freshwater clams and freshwater mussels. There are 247 species of molluscs living in the wild in the Czech Republic. In addition there are at least 11 gastropod species surviving in greenhouses. There are 219 gastropod species (50 freshwater and 169 land species) and 28 bivalve species living in the wild. There are also 11 introduced gastropod species (5 freshwater and 7 land species) and 4 bivalve species living in the wild in the Czech Republic. This is a total of 9 freshwater non-indigenous species living in natural habitats. ;Summary table of number of species There are 2 endemic species of molluscs in the Czech Republic: *'' Alzoniella slovenica'' in Moravia (and in Slovakia too) *'' Bulgarica nitidosa'' in Bohemia. History Historical lists from 19th century or overviews of Czec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animalbase
AnimalBase is a project brought to life in 2004 and is maintained by the University of Göttingen, Germany. The goal of the AnimalBase project is to digitize early zoological literature, provide copyright-free open access to zoological works, and provide manually verified lists of names of zoological genera and species as a free resource for the public. AnimalBase contributed to opening up the classical taxonomic literature, which is considered as useful because access to early literature (especially for the late 18th century) can be difficult for researchers who need the old sources for their taxonomic research. AnimalBase data are public domain. The public use of AnimalBase data is not restricted or conditioned.AnimalBase Project Group, 2005-2010. AnimalBase. Early zoological literature online. World wide web electronic publication http://www.animalbase.uni-goettingen.de accessed 30 July 2010. AnimalBase covers all zoological disciplines. In the field of biodiversity informatics A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encyclopedia Of Life
The ''Encyclopedia of Life'' (''EOL'') is a free, online encyclopedia intended to document all of the 1.9 million living species known to science. It is compiled from existing trusted databases curated by experts and with the assistance of non-experts throughout the world. It aims to build one "infinitely expandable" page for each species, including video, sound, images, graphics, as well as text. In addition, the Encyclopedia incorporates content from the Biodiversity Heritage Library, which digitizes millions of pages of printed literature from the world's major natural history libraries. The project was initially backed by a US$50 million funding commitment, led by the MacArthur Foundation and the Sloan Foundation, who provided US$20 million and US$5 million, respectively. The additional US$25 million came from five cornerstone institutions—the Field Museum, Harvard University, the Marine Biological Laboratory, the Missouri Botanical Garden, and the Smithsonian Institutio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphaerium
''Sphaerium'' is a genus of very small freshwater clams, aquatic bivalve molluscs in the family Sphaeriidae, known as the fingernail clams. The small clams in this genus are unusual in that many of them, such as ''Sphaerium corneum'', can climb around underwater on aquatic plants, using their long and strong foot. Species * Subgenus ''Sphaerium'' Scopoli, 1777 :*''Sphaerium corneum'' (Linnaeus, 1758) – European fingernail clam * Subgenus ''Nucleocyclas'' Alimov & Starobogatov, 1968 :* '' Sphaerium nucleus'' (Studer, 1820) :* '' Sphaerium ovale'' ( A. Férussac, 1807) * Subgenus ''Parasphaerium'' Alimov & Starobogatov, 1968 :*'' Sphaerium nitidum'' Clessin, 1876 – Arctic fingernail clam * Subgenus ''Amesoda'' Rafinesque, 1820 :* '' Sphaerium rivicola'' (Lamarck Jean-Baptiste Pierre Antoine de Monet, chevalier de Lamarck (1 August 1744 – 18 December 1829), often known simply as Lamarck (; ), was a French naturalist, biologist, academic, and soldier. He was an early p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molluscs Of Europe
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 gastropods ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
