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Stygobromus Pizzinii
''Stygobromus pizzinii'', commonly called Pizzini's cave amphipod, is a troglomorphic species of amphipod in family Crangonyctidae Crangonyctidae is a family of cave-dwelling freshwater amphipod crustaceans. It contains the following genera: *'' Amurocrangonyx'' Sidorov & Holsinger, 2007 *'' Bactrurus'' Hay, 1902 *'' Crangonyx'' Bate, 1859 *'' Lyurella'' Derzhavin, .... It is native to District of Columbia, Maryland, Pennsylvania and Virginia in the United States. References Freshwater crustaceans of North America Cave crustaceans Crustaceans described in 1938 pizzinii {{Amphipod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Troglomorphic
Troglomorphism is the morphological adaptation of an animal to living in the constant darkness of caves, characterised by features such as loss of pigment, reduced eyesight or blindness, and frequently with attenuated bodies and/or appendages. The terms troglobitic, stygobitic, stygofauna, troglofauna, and hypogean or hypogeic, are often used for cave-dwelling organisms. A 2012 study by a team from the National University of Singapore found that reductive changes in freshwater cave crabs evolved at the same rate as constructive changes. This shows that both selection and evolution have a role in advancing reductive changes (e.g smaller eyes) and constructive changes (e.g larger claws), making troglomorphic adaptations subject to strong factors that affect an organism's morphology. Troglomorphism occurs in molluscs, velvet worms, arachnids, myriapods, crustaceans, insects, fish, amphibians (notably cave salamanders) and reptiles. To date no mammals or birds have been foun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphipod
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 o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crangonyctidae
Crangonyctidae is a family of cave-dwelling freshwater amphipod crustaceans. It contains the following genera: *'' Amurocrangonyx'' Sidorov & Holsinger, 2007 *'' Bactrurus'' Hay, 1902 *'' Crangonyx'' Bate, 1859 *'' Lyurella'' Derzhavin, 1939 *† '' Palaeogammarus'' Zaddach, 1864 *''Stygobromus ''Stygobromus'' is a genus of amphipod crustaceans that live in subterranean habitats. As well as a large number of species in North America, a smaller number of species are also known from Eurasia. Most of the North American species live in area ...'' Cope, 1872 *'' Stygonyx'' Bousfield & Holsinger, 1989 References Gammaridea Amphipod families {{amphipod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Washington, DC
) , image_skyline = , image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan, National Cathedral , image_flag = Flag of the District of Columbia.svg , image_seal = Seal of the District of Columbia.svg , nickname = D.C., The District , image_map = , map_caption = Interactive map of Washington, D.C. , coordinates = , subdivision_type = Country , subdivision_name = , established_title = Residence Act , established_date = 1790 , named_for = George Washington, Christopher Columbus , established_title1 = Organized , established_date1 = 1801 , established_title2 = Consolidated , established_date2 = 1871 , established_title3 = Home Rule Act ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maryland
Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to its east. Baltimore is the largest city in the state, and the capital is Annapolis, Maryland, Annapolis. Among its occasional nicknames are ''Maryland 400, Old Line State'', the ''Free State'', and the ''Chesapeake Bay State''. It is named after Henrietta Maria, the French-born queen of England, Scotland, and Ireland, who was known then in England as Mary. Before its coastline was explored by Europeans in the 16th century, Maryland was inhabited by several groups of Native Americans – mostly by Algonquian peoples and, to a lesser degree, Iroquoian peoples, Iroquoian and Siouan languages, Siouan. As one of the original Thirteen Colonies of England, Maryland was founded by George Calvert, 1st Baron Ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pennsylvania
Pennsylvania (; (Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, Maryland to its south, West Virginia to its southwest, Ohio to its west, Lake Erie and the Canadian province of Ontario to its northwest, New York to its north, and the Delaware River and New Jersey to its east. Pennsylvania is the List of U.S. states and territories by population, fifth-most populous state in the nation with over 13 million residents 2020 United States census, as of 2020. It is the List of U.S. states and territories by area, 33rd-largest state by area and ranks List of states and territories of the United States by population density, ninth among all states in population density. The southeastern Delaware Valley metropolitan area comprises and surrounds Philadelphia, the state's List of cities in Pennsylvania, largest ... [...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 East Coast of the United States, Atlantic Coast and the Appalachian Mountains. The geography and climate of the Commonwealth (U.S. state), 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, Richmond; Virginia Beach, Virginia, Virginia Beach is the most-populous city, and Fairfax County, Virginia, 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 Native American tribes in Virginia, several indigenous groups, including the Powhatan. In 1607, the London Company established the Colony of Virginia as the first permanent English overseas posse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freshwater Crustaceans Of North America
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include non- salty mineral-rich waters such as chalybeate springs. Fresh water may encompass frozen and meltwater in ice sheets, ice caps, glaciers, snowfields and icebergs, natural precipitations such as rainfall, snowfall, hail/ sleet and graupel, and surface runoffs that form inland bodies of water such as wetlands, ponds, lakes, rivers, streams, as well as groundwater contained in aquifers, subterranean rivers and lakes. Fresh water is the water resource that is of the most and immediate use to humans. Water is critical to the survival of all living organisms. Many organisms can thrive on salt water, but the great majority of higher plants and most insects, amphibians, reptiles, mammals and birds need fresh water to survive. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cave Crustaceans
A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea caves, rock shelters, and grottos, that extend a relatively short distance into the rock and they are called ''exogene'' caves. Caves which extend further underground than the opening is wide are called ''endogene'' caves. Speleology is the science of exploration and study of all aspects of caves and the cave environment. Visiting or exploring caves for recreation may be called ''caving'', ''potholing'', or ''spelunking''. Formation types The formation and development of caves is known as '' speleogenesis''; it can occur over the course of millions of years. Caves can range widely in size, and are formed by various geological processes. These may involve a combination of chemical processes, erosion by water, tectonic forces, microorgan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustaceans Described In 1938
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) lim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
