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Rhachistia Aldabrae
''Rhachistia aldabrae'', the Aldabra banded snail, is a species of air-breathing land snail, a pulmonate gastropod mollusc in the family Cerastidae. The species lives on one atoll in the Seychelles Islands, Indian Ocean, and is easily recognizable for its purplish-blue banded gastropod shell, shell. The species was thought to have died out because of climate change, but was rediscovered in 2014. Description The shell of this snail is very unusual in its coloring: purple, indigo blue, and orange, and this makes the snail very easy to recognize and identify. The Aldabra snail grazes on algae, and thus it is very low on the food chain. The shell of this species is oblong, ovate-conical, rather thick, slightly striated, glossy, in the upper part is pale, in the lower part it is black brown. The shell has seven slightly curved and regularly increasing whorl (mollusc), whorls. The upper 3-4 whorls are blackish, the following are dim bluish. Distribution The Aldabra banded snail i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eduard Von Martens
Eduard von Martens (18 April 1831 – 14 August 1904) also known as ''Carl'' or ''Karl Eduard von Martens'', was a German zoologist. Born in Stuttgart in 1831, von Martens attended university in University of Tübingen, Tübingen, where he graduated in 1855. He then moved to Berlin, where he would be based for the remainder of his career, both at the Zoological Museum of the Berlin University (from 1855) and, from 1859 on, at the . In 1860, he embarked on the ''Thetis'' expedition of the Prussian expedition to Eastern Asia. When the expedition returned to Europe in 1862, von Martens continued to travel around Maritime Southeast Asia for 15 months. He published the results of the "Thetis" expedition in two volumes, constituting the Zoologischer Theil of the "Preussische Expedition nach Ost-Asien." Vol. ii, consisting of 447 pages and 22 plates, contained a very full account of the land molluscs. Back in Berlin, von Martens was curator of the malacological and other invertebrate ... [...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] |
Extinction
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. More than 99% of all species that ever lived on Earth, amounting to over five billion species, are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryote globally, and possibly many times more if microorganisms, like bacteria, are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, dodos, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulletin Of The British Museum
''Bulletin of the Natural History Museum'', formerly known as ''Bulletin of the British Museum (Natural History)'' is a series of scientific journals published by the British Museum, and later by the Natural History Museum of London. Titles in the series included *''Bulletin of the British Museum (Natural History), Botany Series'' *''Bulletin of the British Museum (Natural History), Entomology Series'' *''Bulletin of the British Museum (Natural History), Geology Series'' *''Bulletin of the British Museum (Natural History), Historical Series'' *''Bulletin of the British Museum (Natural History), Mineralogy Series'' *''Bulletin of the British Museum (Natural History), Zoology Series'' Upon transfer to the Natural History Museum, the journals were known as *''Bulletin of the Natural History Museum, Botany Series'' *''Bulletin of the Natural History Museum, Entomology Series'' *''Bulletin of the Natural History Museum, Historical Series'' *''Bulletin of the Natural History Museum, Geol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aldabra
Aldabra is the world's second-largest coral atoll, lying south-east of the continent of Africa. It is part of the Aldabra Group of islands in the Indian Ocean that are part of the Outer Islands of the Seychelles, with a distance of 1,120 km (700 mi) southwest of the capital, Victoria on Mahé Island. History The name Aldabra, originally Al-Hadra or Al-Khadra (with several variants), was given by Arab seafarers for "the atoll’s harsh, sun-baked environment"; this name was included in the Portuguese maps of the 16th century. The islands were already known to the Persians and Arabs, from whom they got their name. They had named the Indian Ocean as Bahr-el zanj. It was visited by Portuguese navigators in 1511. In the middle of the 18th century, the atoll became a dependency of the French colony of Réunion, from where expeditions were made for the capture of the Aldabra giant tortoises. As there are no surface freshwater sources on Aldabra, the interests of the explor ... [...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] |
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral 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 conical tube, the growth of which is coiled into an overall 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 shell has numerous whorls. When the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhachistia Aldabrae Type Description
''Rhachistia'' is a genus of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Cerastidae. MolluscaBase eds. (2022). MolluscaBase. Rhachistia Connolly, 1925. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=818528 on 2022-04-09 The genus ''Rhachistia'' is found in Eastern Africa and Asia. Species Species in the genus ''Rhachistia'' include: * '' Rhachistia adumbratus'' (L. Pfeiffer, 1855) * '' Rhachistia aldabrae'' (von Martens, 1898) - Aldabra banded snail - assumed extinct since 2000, small population found 2014 * '' Rhachistia bengalensis'' (Lamarck, 1822) * '' Rhachistia boehmi'' (E. von Martens, 1895) * '' Rhachistia braunsii'' (von Martens, 1869) (synonym: ''Rhachidina braunsi'' (von Martens, 1869)) * '' Rhachistia catenata'' (E. von Martens, 1860) * '' Rhachistia chiradzuluensis'' (E.A. Smith, 1899) * '' Rhachistia conformalis'' Sutcharit, Naggs & Panha, 2010 * '' Rhachistia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biology Letters
''Biology Letters'' is a peer-reviewed, biological, scientific journal published by the Royal Society. It focuses on the rapid publication of short high quality research articles, reviews and opinion pieces across the biological sciences. ''Biology Letters'' has an average turnaround time of twenty four days from submission to a first decision. The editor-in-chief is Professor David Beerling FRS (University of Sheffield) who is supported by an international Editorial Board of practising scientists. Contents and themes As well as the conventional, short research articles, ''Biology Letters'' has recently published Special Features and Mini Series. While Special Features are a collection of up to 20 articles on a specific theme and published across multiple issues, Mini Series include up to six articles that are published in one issue. Examples of topics in these formats include ocean acidification, fossils, extinction, enhanced rock weathering and the evolutionary ecology of sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climate Change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global average temperature is more rapid than previous changes, and is primarily caused by humans burning fossil fuels. Fossil fuel use, deforestation, and some agricultural and industrial practices increase greenhouse gases, notably carbon dioxide and methane. Greenhouse gases absorb some of the heat that the Earth radiates after it warms from sunlight. Larger amounts of these gases trap more heat in Earth's lower atmosphere, causing global warming. Due to climate change, deserts are expanding, while heat waves and wildfires are becoming more common. Increased warming in the Arctic has contributed to melting permafrost, glacial retreat and sea ice loss. Higher temperatures are also causing m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indian Ocean
The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by the Southern Ocean or Antarctica, depending on the definition in use. Along its core, the Indian Ocean has some large marginal or regional seas such as the Arabian Sea, Laccadive Sea, Bay of Bengal, and Andaman Sea. Etymology The Indian Ocean has been known by its present name since at least 1515 when the Latin form ''Oceanus Orientalis Indicus'' ("Indian Eastern Ocean") is attested, named after Indian subcontinent, India, which projects into it. It was earlier known as the ''Eastern Ocean'', a term that was still in use during the mid-18th century (see map), as opposed to the ''Western Ocean'' (Atlantic Ocean, Atlantic) before the Pacific Ocean, Pacific was surmised. Conversely, Ming treasure voyages, Chinese explorers in the Indian Oce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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