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Stygobromus Dejectus
''Stygobromus dejectus'', commonly called Cascade Cave amphipod, is a troglomorphic species of amphipod in family Crangonyctidae. It is endemic to Texas in the United States. See also * Cascade Caverns Cascade Caverns is a historically, geologically, and biologically important limestone solutional cave south of Boerne, Texas, United States, on 226 Cascade Caverns Road, in Kendall County. It has been commercially operated as a show cave and o ... References Freshwater crustaceans of North America Crustaceans described in 1967 Cave crustaceans dejectus Endemic fauna of Texas {{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] |
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 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Texas
Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by both List of U.S. states and territories by area, area (after Alaska) and List of U.S. states and territories by population, population (after California). Texas shares borders with the states of Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the west, and the Mexico, Mexican States of Mexico, states of Chihuahua (state), Chihuahua, Coahuila, Nuevo León, and Tamaulipas to the south and southwest; and has a coastline with the Gulf of Mexico to the southeast. Houston is the List of cities in Texas by population, most populous city in Texas and the List of United States cities by population, fourth-largest in the U.S., while San Antonio is the second most pop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cascade Caverns
Cascade Caverns is a historically, geologically, and biologically important limestone solutional cave south of Boerne, Texas, United States, on 226 Cascade Caverns Road, in Kendall County. It has been commercially operated as a show cave and open for public tours since 1932. Informal tours were run as far back as 1875, when Dr. Benjamin Hester owned the cave property. The cave was known by the native Lipan Apache people who lived in the area prior to 1800. History Cascade Caverns is part of the Glen Rose Formation, a shallow marine to shoreline geological formation from the Lower Cretaceous period. This formation has been exposed in a large area beginning in South-central Texas, running north through the Texas Hill Country, ending up in North-central Texas. The cave has been open to the environment for many tens of thousands of years, as evidenced by prehistoric animal finds and Lipan Apache artifacts from the 1700s. In the mid-19th century, various legends existed about a ... [...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] |
Crustaceans Described In 1967
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 their ... [...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] |
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 areas which were not covered by the Laurentide Ice Sheet, although a few species seem to have survived under the ice. A number of species are on the IUCN Red List as endangered species (EN) or vulnerable species (VU); all the listed species are endemic to the United States. One species, '' S. lucifugus'', is extinct. ''Stygobromus'' includes the following species: *''Stygobromus abditus'' Holsinger, 1978 (Virginia) *''Stygobromus ackerlyi'' Holsinger, 1978 (Georgia) *''Stygobromus alabamensis'' (Stout, 1911) *''Stygobromus albapinus'' Taylor & Holsinger, 2011 (Nevada) *''Stygobromus allegheniensis'' (Holsinger, 1967) (New York to West Virginia) *''Stygobromus ambulans'' (F. Müller, 1846) *''Stygobromus anastasiae'' Sidorov, Holsinger et T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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