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Stygobromus Kenki
''Stygobromus kenki'' is a rare species of Amphipoda, amphipod, a crustacean. Its common names include Kenk's amphipod, Rock Creek groundwater amphipod, and Rock Creek stygobromid. This species lives only in Washington, D.C., the Calvert Formation in Virginia and Montgomery County, Maryland, in the United States. It can be found only in the Potomac River Drainage basin, watershed. Its entire range is less than 40 square miles. It has only been found at five sites at springs or seeps in the local waterways.USFWSKenk's amphipod (''Stygobromus kenki'') Spotlight Species Action Plan./ref> This species is small, the largest female measuring about 5.5 mm in length and the largest male about 3.7 mm. It can only be identified by microscopic examination, which requires that the specimen be killed; therefore, scientists prefer not to attempt identification of these rare amphipods. The species lives in and near water in freshwater habitat. It can be found in detritus and sediment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphipoda
Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods range in size from and are mostly detritivores or scavengers. There are more than 9,900 amphipod species so far described. They are mostly marine animals, but are found in almost all aquatic environments. Some 1,900 species live in fresh water, and the order also includes the terrestrial sandhoppers such as ''Talitrus saltator''. Etymology and names The name ''Amphipoda'' comes, via New Latin ', from the Greek roots 'on both/all sides' and 'foot'. This contrasts with the related Isopoda, which have a single kind of thoracic leg. Particularly among anglers, amphipods are known as ''freshwater shrimp'', ''scuds'', or ''sideswimmers''. Description Anatomy The body of an amphipod is divided into 13 segments, which can be grouped into a head, a thorax and an abdomen. The head is fused to the thorax, and bears two pairs of antennae and one pair of s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustacean
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can be treated as a subphylum under the clade Mandibulata. It is now well accepted that the hexapods emerged deep in the Crustacean group, with the completed group referred to as Pancrustacea. Some crustaceans (Remipedia, Cephalocarida, Branchiopoda) are more closely related to insects and the other hexapods than they are to certain other crustaceans. The 67,000 described species range in size from '' Stygotantulus stocki'' at , to the Japanese spider crab with a leg span of up to and a mass of . Like other arthropods, crustaceans have an exoskeleton, which they moult to grow. They are distinguished from other groups of arthropods, such as insects, myriapods and chelicerates, by the possession of biramous (two-parted) limbs, and by th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Washington, D
Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered on Washington, D.C. * George Washington (1732–1799), the first president of the United States Washington may also refer to: Places England * Washington, Tyne and Wear, a town in the City of Sunderland metropolitan borough ** Washington Old Hall, ancestral home of the family of George Washington * Washington, West Sussex, a village and civil parish Greenland * Cape Washington, Greenland * Washington Land Philippines *New Washington, Aklan, a municipality *Washington, a barangay in Catarman, Northern Samar *Washington, a barangay in Escalante, Negros Occidental *Washington, a barangay in San Jacinto, Masbate *Washington, a barangay in Surigao City United States * Washington, Wisconsin (other) * Fort Washington (other) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calvert Formation
The Calvert Formation is a geologic formation in Maryland, Virginia, and Delaware. It preserves fossils dating back to the early to middle Miocene epoch of the Neogene period. The formation is a destination for amateur fossil hunters as well as professional paleontologists. It is one of the three formations which make up the Calvert Cliffs, all of which are part of the Chesapeake Group. Fossils The Calvert Formation is extremely fossiliferous. Some of the fossil species represented include the following: Sharks * ''Otodus megalodon'' * ''Otodus chubutensis'' * ''Carcharodon hastalis'' * '' Isurus oxyrhincus'' * '' Physogaleus contortus'' * '' Physogaleus hemmooriensis'' * ''Galeocerdo aduncus'' * '' Carcharhinus'' * ''Hemipristis serra'' * '' Squatina sp.'' * ''Squalus sp.'' * '' Echinorhinus blakei'' * '' Notorhyncus cepedianus'' * '' Hexanchus gigas'' * '' Carcharias'' * ''Carcharoides catticus'' * '' Isurus retroflexus'' * '' Parotodus benedeni'' * ''Alopias vulpinus'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virginia
Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the Atlantic Coast and the Appalachian Mountains. The geography and climate of the Commonwealth are shaped by the Blue Ridge Mountains and the Chesapeake Bay, which provide habitat for much of its flora and fauna. The capital of the Commonwealth is Richmond; Virginia Beach is the most-populous city, and Fairfax County is the most-populous political subdivision. The Commonwealth's population was over 8.65million, with 36% of them living in the Baltimore–Washington metropolitan area. The area's history begins with several indigenous groups, including the Powhatan. In 1607, the London Company established the Colony of Virginia as the first permanent English colony in the New World. Virginia's state nickname, the Old Dominion, is a reference to this status. Slave labor and land acquired from displaced native tribes fueled the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Montgomery County, Maryland
Montgomery County is the most populous county in the state of Maryland. As of the 2020 census, the county's population was 1,062,061, increasing by 9.3% from 2010. The county seat and largest municipality is Rockville, although the census-designated place of Germantown is the most populous place within the county. Montgomery County, which adjoins Washington, D.C., is part of the Washington–Arlington–Alexandria, DC–VA–MD–WV metropolitan statistical area, which in turn forms part of the Baltimore–Washington combined statistical area. Most of the county's residents live in unincorporated locales, of which the most urban are Silver Spring and Bethesda, although the incorporated cities of Rockville and Gaithersburg are also large population centers, as are many smaller but significant places. The average household income in Montgomery County is among the highest in the United States. It has the highest percentage (29.2%) of residents over 25 years of age who hold po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potomac River
The Potomac River () drains the Mid-Atlantic United States, flowing from the Potomac Highlands into Chesapeake Bay. It is long,U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map. Retrieved August 15, 2011 with a drainage area of 14,700 square miles (38,000 km2), and is the fourth-largest river along the East Coast of the United States and the 21st-largest in the United States. Over 5 million people live within its watershed. The river forms part of the borders between Maryland and Washington, D.C. on the left descending bank and between West Virginia and Virginia on the right descending bank. Except for a small portion of its headwaters in West Virginia, the North Branch Potomac River is considered part of Maryland to the low-water mark on the opposite bank. The South Branch Potomac River lies completely within the state of West Virginia except for its headwaters, which lie in Virginia. Course The Potomac River runs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drainage Basin
A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, the '' drainage divide'', made up of a succession of elevated features, such as ridges and hills. A basin may consist of smaller basins that merge at river confluences, forming a hierarchical pattern. Other terms for a drainage basin are catchment area, catchment basin, drainage area, river basin, water basin, and impluvium. In North America, they are commonly called a watershed, though in other English-speaking places, "watershed" is used only in its original sense, that of a drainage divide. In a closed drainage basin, or endorheic basin, the water converges to a single point inside the basin, known as a sink, which may be a permanent lake, a dry lake, or a point where surface water is lost underground. Drainage basins are similar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rock Creek Park
Rock Creek Park is a large urban park that bisects the Northwest quadrant of Washington, D.C. The park was created by an Act of Congress in 1890 and today is administered by the National Park Service. In addition to the park proper, the Rock Creek administrative unit of the National Park Service administers various other federally owned properties in the District of Columbia located to the north and west of the National Mall, including Meridian Hill Park on 16th Street, N.W., the Old Stone House in Georgetown, and certain of the Fort Circle Parks, a series of batteries and forts encircling the District of Columbia for its defense during the U.S. Civil War. History Rock Creek Park was established by an act of Congress signed into law by President Benjamin Harrison on September 27, 1890, following active advocacy by Charles C. Glover and other civic leaders and in the wake of the creation of the National Zoo the preceding year. It was only the third national park estab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roman Kenk
Roman Kenk (November 25, 1898 – October 2, 1988) was a Slovenian, later American, zoologist. Life Roman Kenk was born in Ljubljana and baptized ''Roman Marija Kenk''. He received his PhD in zoology at the University of Graz, Austria, in 1921, and worked at the University of Ljubljana. From 1931 to 1932, and again in the summer of 1933, Kenk stayed at the University of Virginia in the United States, where he met Ada Antonio Blanco, who had come from Puerto Rico. They married in 1933 and returned to Ljubljana, where they stayed for 5 years and then moved to Puerto Rico. Four years later, in 1942, Kenk became a naturalized American citizen. From 1948 to 1965, Kenk was employed at the Library of Congress. Later, he became a research associate at the Department of Invertebrate Zoology of the Smithsonian Institution, Washington, D. C., where he worked until his death in 1988.Faubel, AnnoMemories, Biographies and Bibliographies of Famous Turbellariologists Kenk's life was ded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus comes above species and below family (taxonomy), family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stygobromus Hayi
''Stygobromus hayi'' is a rare species of crustacean known by the common name Hay's Spring amphipod. It is endemic to the District of Columbia in the United States, where it occurs only in Rock Creek, a tributary of the Potomac River.Pavek, DUrban refuge for rare amphipods in the National Capital Region.Natural Resource Year in Review 2001. National Park Service. It is a federally listed endangered species, is listed as ''Endangered'' on the IUCN Red List, and as '' Critically Imperiled'' by NatureServe. One of three amphipods that are found only in the District of Columbia, this species has been called "Washington D.C.'s most famous endemic."''Stygobromus hayi''. The Nature Conservancy. Hay's spring amphipod lives in five [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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