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Dolomedes Tenebrosus
''Dolomedes tenebrosus'' or dark fishing spider is a fishing spider found in the USA and Canada.Weber, Larry. (2003). ''Spiders of the North Woods.'' Duluth, MN:Kollath+Stensaas. pp. 104-105. It is able to bite humans but will run from people. In most cases, the bite is no more severe than a bee or wasp sting. Description Female bodies are 15–26 mm; males are 7–13 mm. Legs range from 50–90 mm. The spider is a pale to dark brown colour with several chevron markers and lighter stripes around its legs. It is similar to '' D. scriptus''. The legs are banded with brown/black annulations on the femora and reddish-brown/black annulations on the tibia. Habitat They are found in wooded areas and dwell on tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...s. R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicholas Marcellus Hentz
Nicholas Marcellus Hentz (July 25, 1797 – November 4, 1856) was a French American educator and arachnologist. Biography Hentz was born in Versailles, France. He was the youngest child of Charles Nicholas Arnould Hentz and Marie-Anne Therese Daubree Hentz. He studied medicine and learned the art of miniature painting in Paris. His father was an active Republican and participant in the French Revolution. Upon the restoration of the Bourbons in 1815, his father was banished from France. So, in 1816, Marcellus immigrated with his family to the United States, where they settled in Wilkes-Barre, Pennsylvania. He taught French and miniature painting in Boston, Philadelphia, and other places. He became a member of the Academy of Natural Sciences of Philadelphia (ANSP) in 1819. His illustrations were published in their journal. Among these illustrations are three well known watercolors, two of which are of freshwater fish from Alabama (painted in 1847) and one is a miniature of Hen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolomedes
''Dolomedes'' is a genus of large spiders of the family Pisauridae. 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 '' 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; like other spiders they then inject venom with their hollow jaws 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 "δολομήδης" which means wily, deceitful. There are over a hundred species of ''Dolomedes'' throughout the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Penn State College Of Agricultural Sciences
The Penn State College of Agricultural Sciences offers 17 undergraduate majors, 23 minors, and graduate programs in 18 major areas. The college awarded the nation's first baccalaureate degrees in agriculture in 1861. With 9 academic departments and 67 cooperative extension offices, one in each of Pennsylvania's counties, the college is widely recognized as one of the nation's top institutions for agricultural research and education programs. History In 1855, before the Penn State College of Agricultural Sciences, it was a high school known as The Farmer's High School run by Evan Pugh. Pugh helped to transform the Farmer's High School into the Penn State College of Agricultural Sciences by supporting Congress to pass the Morrill Land-Grant Act. The only land-grant university in Pennsylvania, Penn State became one of the nation's very first when President Abraham Lincoln signed the Morrill Act into law in 1862. As a result, government receives money from the sales of land to h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dark Fishing Spider (Dolomedes Tenebrosus)
Darkness, the direct opposite of lightness, is defined as a lack of illumination, an absence of visible light, or a surface that absorbs light, such as black or brown. Human vision is unable to distinguish colors in conditions of very low luminance. This is because the hue sensitive photoreceptor cells on the retina are inactive when light levels are insufficient, in the range of visual perception referred to as scotopic vision. The emotional response to darkness has generated metaphorical usages of the term in many cultures, often used to describe an unhappy or foreboding feeling. Referring to a time of day, complete darkness occurs when the Sun is more than 18° below the horizon, without the effects of twilight on the night sky. Scientific Perception The perception of darkness differs from the mere absence of light due to the effects of after images on perception. In perceiving, the eye is active, and the part of the retina that is unstimulated produces a complemen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolomedes Tenebrosus Eyeset
''Dolomedes'' is a genus of large spiders of the family Pisauridae. 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 '' 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; like other spiders they then inject venom with their hollow jaws 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 "δολομήδης" which means wily, deceitful. There are over a hundred species of ''Dolomedes'' throughout the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolomedes Scriptus
''Dolomedes scriptus'' is a fishing spider found in the United States and Canada, known as the striped fishing spider.Weber, Larry. (2003) Spiders of the North Woods. Duluth, MN:Kollath+Stensaas, 106-107. Female spiders can grow to be over 6 cm in legspan. The spider is a pale brown colour with lighter stripes around its legs and a stripe down each side of the body. It is similar to '' D. tenebrosus''. References Further reading''Dolomedes scriptus'' The Nearctic Spider Database, GBIF *Bishop, S. C. 1924. A revision of the Pisauridae of the United States. ''New York St. Mus. Bull.'' 252: 1-140. *Carico, J. E. 1973. The Nearctic species of the genus Dolomedes (Araneae: Pisauridae). ''Bull. Mus. comp. Zool. Harv''. 144: 435-488. *Carico, J. E. & P. C. Holt. 1964. A comparative study of the female copulatory apparatus of certain species in the spider genus Dolomedes (Pisauridae: Araneae). ''Tech. Bull. agric. Exp. Stat. Blacksburg Virg''. 172: 1-27. *Comstock, J. H. 1940. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annulation
In organic chemistry annulation (from the Latin ''anellus'' for "little ring"; occasionally annelation) is a chemical reaction in which a new ring is constructed on a molecule. : Examples are the Robinson annulation, Danheiser annulation and certain cycloadditions. Annular molecules are constructed from side-on condensed cyclic segments, for example helicenes and acenes. In transannulation a bicyclic molecule is created by intramolecular carbon-carbon bond formation in a large monocyclic ring. An example is the samarium(II) iodide induced ketone - alkene cyclization of ''5-methylenecyclooctanone'' which proceeds through a ketyl intermediate: : Benzannulation The term benzannulated compounds refers to derivatives of cyclic compounds (usually aromatic) which are fused to a benzene ring. Examples are listed in the table below: In contemporary chemical literature, the term benzannulation also means "construction of benzene rings from acyclic precursors". upright=1.4, Protonati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Femora
The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with the tibia (shinbone) and patella (kneecap), forming the knee joint. By most measures the two (left and right) femurs are the strongest bones of the body, and in humans, the largest and thickest. Structure The femur is the only bone in the upper leg. The two femurs converge medially toward the knees, where they articulate with the proximal ends of the tibiae. The angle of convergence of the femora is a major factor in determining the femoral-tibial angle. Human females have thicker pelvic bones, causing their femora to converge more than in males. In the condition ''genu valgum'' (knock knee) the femurs converge so much that the knees touch one another. The opposite extreme is ''genu varum'' (bow-leggedness). In the general population ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tibia
The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects the knee with the ankle. The tibia is found on the medial side of the leg next to the fibula and closer to the median plane. The tibia is connected to the fibula by the interosseous membrane of leg, forming a type of fibrous joint called a syndesmosis with very little movement. The tibia is named for the flute '' tibia''. It is the second largest bone in the human body, after the femur. The leg bones are the strongest long bones as they support the rest of the body. Structure In human anatomy, the tibia is the second largest bone next to the femur. As in other vertebrates the tibia is one of two bones in the lower leg, the other being the fibula, and is a component of the knee and ankle joints. The ossification or formation of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tree
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height. In wider definitions, the taller palms, tree ferns, bananas, and bamboos are also trees. Trees are not a taxonomic group but include a variety of plant species that have independently evolved a trunk and branches as a way to tower above other plants to compete for sunlight. The majority of tree species are angiosperms or hardwoods; of the rest, many are gymnosperms or softwoods. Trees tend to be long-lived, some reaching several thousand years old. Trees have been in existence for 370 million years. It is estimated that there are some three trillion mature trees in the world. A tree typically has many secondary branches supported clear of the ground by the trunk. This trunk typicall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiders Of North America
Spiders (order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species diversity among all orders of organisms. Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every land habitat. , 50,356 spider species in 132 families have been recorded by taxonomists. However, there has been debate among scientists about how families should be classified, with over 20 different classifications proposed since 1900. Anatomically, spiders (as with all arachnids) differ from other arthropods in that the usual body segments are fused into two tagmata, the cephalothorax or prosoma, and the opisthosoma, or abdomen, and joined by a small, cylindrical pedicel, however, as there is currently neither paleontological nor embryological evidence that spiders ever had a separ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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