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Great Raft Spider
The great raft spider or fen raft spider (''Dolomedes plantarius'') is a European species of spider in the family Dolomedidae. Like other ''Dolomedes'' spiders, it is semiaquatic, hunting its prey on the surface of water. It occurs mainly in neutral to alkaline, unpolluted water of fens and grazing marsh. Taxonomy The species was first described by arachnologist Carl Alexander Clerck in 1757 as ''Araneus plantarius''. Its genus was reclassified by Pierre André Latreille in 1804 to ''Dolomedes''. The species has also been described under the name ''Aranea viridata'' by Müller and as ''Dolomedes riparius'' by Hahn. The species is currently recognised as ''Dolomedes plantarius'' and has two widely recognised common names: the great raft spider and the fen raft spider. Morphology ''D. plantarius'' is a large species within its range. Adult females can have bodies of slightly over 20mm in length with a span of 70mm including their legs. It is typically black or brown in col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Alexander Clerck
Carl Alexander Clerck (1709 – 22 July 1765) was a Sweden, Swedish entomologist and arachnology, arachnologist. Clerck came from a family in the petty Swedish nobility, nobility and entered the University of Uppsala in 1726. Little is known of his studies; although a contemporary of Carl Linnaeus, Linnaeus, it is unknown whether he had any contact with him during his time in Uppsala. His limited means forced him to leave university early and enter into government service, later ending up working in the administration of the City of Stockholm. His interest in natural history appears to have come at a more mature age, influenced by a lecture of Linnaeus he attended in Stockholm in 1739. In the following years he collected and categorized many spiders, published together with more general observations on the morphology and behaviour of spiders, in his ''Svenska Spindlar'' ("Swedish spiders", 1757, also known by its Latin subtitle, ''Aranei Suecici''). He also started the publication ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dragonfly
A dragonfly is a flying insect belonging to the infraorder Anisoptera below the order Odonata. About 3,000 extant species of dragonflies are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threatens dragonfly populations around the world. Adult dragonflies are characterised by a pair of large, multifaceted, compound eyes, two pairs of strong, transparent wings, sometimes with coloured patches, and an elongated body. Many dragonflies have brilliant iridescent or metallic colours produced by structural coloration, making them conspicuous in flight. An adult dragonfly's compound eyes have nearly 24,000 ommatidia each. Dragonflies can be mistaken for the closely related damselflies, which make up the other odonatan infraorder ( Zygoptera) and are similar in body plan, though usually lighter in build; however, the wings of most dragonflies are held flat and away from the body, while damselflies hold their wings folded at rest, al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulgaria
Bulgaria, officially the Republic of Bulgaria, is a country in Southeast Europe. It is situated on the eastern portion of the Balkans directly south of the Danube river and west of the Black Sea. Bulgaria is bordered by Greece and Turkey to the south, Serbia and North Macedonia to the west, and Romania to the north. It covers a territory of and is the tenth largest within the European Union and the List of European countries by area, sixteenth-largest country in Europe by area. Sofia is the nation's capital and List of cities and towns in Bulgaria, largest city; other major cities include Burgas, Plovdiv, and Varna, Bulgaria, Varna. One of the earliest societies in the lands of modern-day Bulgaria was the Karanovo culture (6,500 BC). In the 6th to 3rd century BC, the region was a battleground for ancient Thracians, Persians, Celts and Ancient Macedonians, Macedonians; stability came when the Roman Empire conquered the region in AD 45. After the Roman state splintered, trib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belgium
Belgium, officially the Kingdom of Belgium, is a country in Northwestern Europe. Situated in a coastal lowland region known as the Low Countries, it is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to the south, and the North Sea to the west. Belgium covers an area of and has a population of more than 11.8 million; its population density of ranks List of countries and dependencies by population density, 22nd in the world and Area and population of European countries, sixth in Europe. The capital and Metropolitan areas in Belgium, largest metropolitan region is City of Brussels, Brussels; other major cities are Antwerp, Ghent, Charleroi, Liège, Bruges, Namur, and Leuven. Belgium is a parliamentary system, parliamentary constitutional monarchy with a complex Federation, federal system structured on regional and linguistic grounds. The country is divided into three highly autonomous Communities, regions and language areas o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belarus
Belarus, officially the Republic of Belarus, is a landlocked country in Eastern Europe. It is bordered by Russia to the east and northeast, Ukraine to the south, Poland to the west, and Lithuania and Latvia to the northwest. Belarus spans an area of with a population of . The country has a hemiboreal climate and is administratively divided into Regions of Belarus, six regions. Minsk is the capital and List of cities and largest towns in Belarus, largest city; it is administered separately as a city with special status. For most of the medieval period, the lands of modern-day Belarus was ruled by independent city-states such as the Principality of Polotsk. Around 1300 these lands came fully under the Grand Duchy of Lithuania and subsequently by the Polish–Lithuanian Commonwealth; this period lasted for 500 years until the Partitions of Poland, 1792-1795 partitions of Poland-Lithuania placed Belarus within the Belarusian history in the Russian Empire, Russian Empire for the fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Austria
Austria, formally the Republic of Austria, is a landlocked country in Central Europe, lying in the Eastern Alps. It is a federation of nine Federal states of Austria, states, of which the capital Vienna is the List of largest cities in Austria, most populous city and state. Austria is bordered by Germany to the northwest, the Czech Republic to the north, Slovakia to the northeast, Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the west. The country occupies an area of and has Austrians, a population of around 9 million. The area of today's Austria has been inhabited since at least the Paleolithic, Paleolithic period. Around 400 BC, it was inhabited by the Celts and then annexed by the Roman Empire, Romans in the late 1st century BC. Christianization in the region began in the 4th and 5th centuries, during the late Western Roman Empire, Roman period, followed by the arrival of numerous Germanic tribes during the Migration Period. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolomedes Plantarius Spider
''Dolomedes'' is a genus of large spiders of the family Dolomedidae. They are also known as fishing spiders, raft spiders, dock spiders or wharf spiders. Almost all ''Dolomedes'' species are semiaquatic, with the exception of the tree-dwelling ''Dolomedes albineus, D. albineus'' of the southeastern United States. Many species have a striking pale stripe down each side of the body. They hunt by waiting at the edge of a pool or stream, then when they detect the ripples from prey, they run across the surface to subdue it using their foremost legs, which are tipped with small claws; then injecting venom with their hollow chelicerae to kill and digest the prey. They mainly eat insects, but some larger species are able to catch small fish. They can also climb beneath the water, when they become encased in a silvery film of air. "''Dolomedes''" is derived from the Greek word which means wily, deceitful. There are over a hundred species of ''Dolomedes'' throughout the world; examples ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suffolk Wildlife Trust
Suffolk Wildlife Trust (SWT) describes itself as the county's "nature charity – the only organisation dedicated wholly to safeguarding Suffolk's wildlife and countryside." It is a registered charity, and its headquarters is at Brooke House in Ashbocking, near Ipswich. It was founded in 1961,About us , Suffolk Wildlife Trust. Retrieved 3 March 2014. and is one of 46 wildlife trusts covering Great Britain and Northern Ireland. As of March 2017, it has 13,200 members, and it manages of land in 60 nature reserves, most of which are open to the public. It had an income of £3.9 milli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spider Web
A spider web, spiderweb, spider's web, or cobweb (from the archaic word ''Wikt:coppe, coppe'', meaning 'spider') is a structure created by a spider out of proteinaceous spider silk extruded from its spinnerets, generally meant to catch its prey. Spider webs have existed for at least 100 million years, as witnessed in a rare find of Early Cretaceous amber from Sussex, in southern England. Many spiders build webs specifically to trap and catch insects to eat. However, not all spiders catch their prey in webs, and some do not build webs at all. The term "spider web" is typically used to refer to a web that is apparently still in use (i.e., clean), whereas "cobweb" refers to a seemingly abandoned (i.e., dusty) web. However, the word "cobweb" is also used by biologists to describe the tangled three-dimensional web of some spiders of the family Theridiidae. While this large family is known as the cobweb spiders, they actually have a huge range of web architectures; other names for thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spider Silk
Spider silk is a protein fibre or silk spun by spiders. Spiders use silk to make webs or other structures that function as adhesive traps to catch prey, to entangle and restrain prey before biting, to transmit tactile information, or as nests or cocoons to protect their offspring. They can use the silk to suspend themselves from height, to float through the air, or to glide away from predators. Most spiders vary the thickness and adhesiveness of their silk according to its use. In some cases, spiders may use silk as a food source. While methods have been developed to collect silk from a spider by force, gathering silk from many spiders is more difficult than from silk-spinning organisms such as silkworms. All spiders produce silk, although some spiders do not make webs. Silk is tied to courtship and mating. Silk produced by females provides a transmission channel for male vibratory courtship signals, while webs and draglines provide a substrate for female sex pheromone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hibernation
Hibernation is a state of minimal activity and metabolic reduction entered by some animal species. Hibernation is a seasonal heterothermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It is most commonly used to pass through winter months – called overwintering. Although traditionally reserved for "deep" hibernators such as rodents, the term has been redefined to include animals such as bears and is now applied based on active metabolic suppression rather than any absolute decline in body temperature. Many experts believe that the processes of daily torpor and hibernation form a continuum and use similar mechanisms. The equivalent during the summer months is aestivation. Hibernation functions to conserve energy when sufficient food is not available. To achieve this energy saving, an endothermic animal decreases its metabolic rate and thereby its body temperature. Hibernation may last days, weeks, or months—depending on t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Tension
Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension (physics), tension is what allows objects with a higher density than water such as razor blades and insects (e.g. Gerridae, water striders) to float on a water surface without becoming even partly submerged. At liquid–air interfaces, surface tension results from the greater attraction of liquid molecules to each other (due to Cohesion (chemistry), cohesion) than to the molecules in the air (due to adhesion). There are two primary mechanisms in play. One is an inward force on the surface molecules causing the liquid to contract. Second is a tangential force parallel to the surface of the liquid. This ''tangential'' force is generally referred to as the surface tension. The net effect is the liquid behaves as if its surface were covered with a stretched elastic membrane. But this analogy must not be taken too far as the tension in an elastic membrane i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
