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New Zealand Mud Snail
The New Zealand mud snail (''Potamopyrgus antipodarum'') is a species of very small freshwater snail with a gill and an operculum. This aquatic gastropod mollusk is in the family Tateidae. It is native to New Zealand, where it is found throughout the country, but it has been introduced to many other countries, where it is often considered an invasive species because populations of the snail can reach very high densities. Shell description The shell of ''Potamopyrgus antipodarum'' is elongated and has dextral coiling, with 7 to 8 whorls. Between whorls are deep grooves. Shell colors vary from gray and dark brown to light brown. The average height of the shell is approximately 5 mm (\begin \frac \end in); maximum size is approximately 12 mm (\begin \frac \end in). The snail is usually 4–6 mm in length in the Great Lakes, but grows to 12 mm in its native range. It is an operculate snail, with a 'lid' that can seal the opening of its shell. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Edward Gray
John Edward Gray, FRS (12 February 1800 – 7 March 1875) was a British zoologist. He was the elder brother of zoologist George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray (1766–1828). The same is used for a zoological name. Gray was keeper of zoology at the British Museum in London from 1840 until Christmas 1874, before the natural history holdings were split off to the Natural History Museum. He published several catalogues of the museum collections that included comprehensive discussions of animal groups and descriptions of new species. He improved the zoological collections to make them amongst the best in the world. Biography Gray was born in Walsall, but his family soon moved to London, where Gray studied medicine. He assisted his father in writing ''The Natural Arrangement of British Plants'' (1821). After being blackballed by the Linnean Society of London, Gray shifted his interest from botany to zoology. He began his zoologica ... [...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] |
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] |
Black Sea
The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Romania, Russia, Turkey, and Ukraine. The Black Sea is supplied by major rivers, principally the Danube, Dnieper, and Don. Consequently, while six countries have a coastline on the sea, its drainage basin includes parts of 24 countries in Europe. The Black Sea covers (not including the Sea of Azov), has a maximum depth of , and a volume of . Most of its coasts ascend rapidly. These rises are the Pontic Mountains to the south, bar the southwest-facing peninsulas, the Caucasus Mountains to the east, and the Crimean Mountains to the mid-north. In the west, the coast is generally small floodplains below foothills such as the Strandzha; Cape Emine, a dwindling of the east end of the Balkan Mountains; and the Dobruja Plateau considerably farth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Non-marine Molluscs Of Poland
There are approximately 265 species of non-marine molluscs living in the wild in Poland. Systematic list The list is in zoological order rather than alphabetical order. The Polish common name (where one exists) of each mollusc is given first, in parentheses, and then the scientific name. The source for the non-marine species on this list isCLECOM-PROJECT: Checklist of species-group taxa of continental Mollusca living in the Netherlands (CLECOM Section I) 14-07-2002with changes. Gastropoda Neritidae * (rozdepka rzeczna) '' Theodoxus fluviatilis fluviatilis'' (Linnaeus, 1758) ** '' Theodoxus fluviatilis littoralis'' (Linnaeus, 1758) Aciculidae * (igliczek karpacki) ''Acicula parcelineata'' (Clessin, 1911) * (igliczek lśniący) ''Platyla polita'' (Hartmann, 1840) Viviparidae * (żyworódka pospolita) ''Viviparus viviparus'' (Linnaeus, 1758) * (żyworódka rzeczna) ''Viviparus contectus'' (Millet, 1813) Bithyniidae * (zagrzebka pospolita) '' Bithynia tentaculata'' (Linnaeu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Non-marine Molluscs Of Germany
This list of non-marine molluscs of Germany is a list of the molluscs that live in Germany, except for the marine (saltwater) species. In other words, this list includes the land snails and slugs, the freshwater snails and the freshwater clams and mussels. There are 390 species (including subspecies) of molluscs living in the wild in Germany. In addition there is at least 1 gastropod species that lives only in greenhouses. There are ??? species of gastropods (69 species of freshwater gastropods, ??? species of land gastropods) and 36 species of bivalves living in the wild. There are 8 introduced species of gastropods (7 freshwater and 1 land species) and 1 species of non-indigenous bivalve living in the wild in Germany. That makes a total of 8 freshwater non-indigenous species of wild molluscs. ;Summary table of number of species There are only orders, families and species in the list. The German name is in brackets. Non-indigenous species only occurring greenhouses in Ger ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Non-marine Molluscs Of Great Britain
This list comprises 231 species of non-marine molluscs that have been recorded in the scientific literature as part of the fauna of the island of Great Britain; this total excludes species found only in hothouses and aquaria. The list includes terrestrial and aquatic gastropods, and aquatic bivalves. Molluscs that are fully marine (adapted to live in the sea) are not included here, except for two marine pulmonate snails. In other words, this list includes land snails and slugs, and freshwater and brackish water snails. It also includes freshwater mussels and clams, including some that can tolerate brackish water. Great Britain is a European island in the northeastern Atlantic, comprising the contiguous countries of England, Scotland and Wales. (Great Britain is not the same entity as the United Kingdom of Great Britain and Northern Ireland; for more information on the complex nomenclature of this area, please see terminology of the British Isles.) The mollusc fauna of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Non-marine Molluscs Of Ireland
This list of the non-marine molluscs of Ireland comprises 165 species of non-marine molluscs which have been recorded as part of the fauna of Ireland. These are terrestrial and aquatic gastropods, and bivalves; the list does not include species of molluscs which are considered to be fully marine. In other words: this list includes land snails and slugs, and freshwater and brackish water snails. It also includes freshwater mussels and freshwater clams, including some that can tolerate brackish water. Molluscs that are fully adapted to live in the sea are not included here. Ireland is an island in the northeastern Atlantic. It consists of the Republic of Ireland, also known simply as Ireland (or in the Irish language ''Éire''), and Northern Ireland, which is part of the United Kingdom. The mollusc fauna of the island of Ireland has not been as thoroughly researched as that of the island of Great Britain, and therefore it is possible that some uncommon and local species (whether ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naturalisation (biology)
Naturalisation (or naturalization) is the ecological phenomenon through which a species, taxon, or population of exotic (as opposed to native) origin integrates into a given ecosystem, becoming capable of reproducing and growing in it, and proceeds to disseminate spontaneously. In some instances, the presence of a species in a given ecosystem is so ancient that it cannot be presupposed whether it is native or introduced. Generally, any introduced species may (in the wild) either go extinct or naturalise in its new environment. Some populations do not sustain themselves reproductively, but exist because of continued influx from elsewhere. Such a non-sustaining population, or the individuals within it, are said to be adventive. Cultivated plants are a major source of adventive populations. The above refers to ''naturalize'' as an intransitive verb, as in, "The species naturalized". In North America it is common to use ''naturalize'' as a transitive verb, as in, "City staff nat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island country by area, covering . New Zealand is about east of Australia across the Tasman Sea and south of the islands of New Caledonia, Fiji, and Tonga. The country's varied topography and sharp mountain peaks, including the Southern Alps, owe much to tectonic uplift and volcanic eruptions. New Zealand's capital city is Wellington, and its most populous city is Auckland. The islands of New Zealand were the last large habitable land to be settled by humans. Between about 1280 and 1350, Polynesians began to settle in the islands and then developed a distinctive Māori culture. In 1642, the Dutch explorer Abel Tasman became the first European to sight and record New Zealand. In 1840, representatives of the United Kingdom and Māori chiefs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemism
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example '' Cytisus aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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