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Percina Shumardi
''Percina shumardi'' (river darter) is a benthic species of freshwater ray-finned fish, a darter from the subfamily Etheostomatinae, part of the family Percidae, which also contains the perches, ruffes and pikeperches. It is native to North America. It is an inhabitant of small and medium rivers where it occurs in rocky riffles with clear, fast-flowing water. The river darter can reach up to 7.3 cm in length and has an average lifespan of three years. It can be distinguished from other darters by its unique front and rear spots on the dorsal fin. Geographic distribution The river darter is a species native only to the United States and Canada. Within Canada, the river darter is native to southern regions including the Hudson Bay basin, Ontario, and Manitoba. Within the United States, the river darter is native to a band that starts northward in Canada and extends into Minnesota and North Dakota and continues to the Gulf drainages in Alabama and Texas. The river darter is th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Frédéric Girard
Charles Frédéric Girard (8 March 1822 – 29 January 1895) was a French biologist specializing in ichthyology and herpetology. Born in Mulhouse, France, he studied at the College of Neuchâtel, Switzerland, as a student of Louis Agassiz. In 1847, he accompanied Agassiz as his assistant to Harvard University. Three years later, Spencer Fullerton Baird called him to the Smithsonian Institution to work on its growing collection of North American reptiles, amphibians and fishes. He worked at the museum for the next ten years and published numerous papers, many in collaboration with Baird. In 1854, he was naturalized as a U.S. citizen. Besides his work at the Smithsonian, he managed to earn an M.D. from Georgetown University in Washington, D.C. in 1856. In 1859 he returned to France and was awarded the Cuvier Prize by the Institute of France for his work on the North American reptiles and fishes two years later. When the American Civil War broke out, he joined the Confederate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alabama
(We dare defend our rights) , anthem = "Alabama (state song), Alabama" , image_map = Alabama in United States.svg , seat = Montgomery, Alabama, Montgomery , LargestCity = Huntsville, Alabama, Huntsville , LargestCounty = Baldwin County, Alabama, Baldwin County , LargestMetro = Birmingham metropolitan area, Alabama, Greater Birmingham , area_total_km2 = 135,765 , area_total_sq_mi = 52,419 , area_land_km2 = 131,426 , area_land_sq_mi = 50,744 , area_water_km2 = 4,338 , area_water_sq_mi = 1,675 , area_water_percent = 3.2 , area_rank = 30th , length_km = 531 , length_mi = 330 , width_km = 305 , width_mi = 190 , Latitude = 30°11' N to 35° N , Longitude = 84°53' W to 88°28' W , elevation_m = 150 , elevation_ft = 500 , elevation_max_m = 735.5 , elevation_max_ft = 2,413 , elevation_max_point = Mount Cheaha , elevation_min_m = 0 , elevation_min_ft = 0 , elevation_min_point = Gulf of Mexico , OfficialLang = English language, English , Languages = * English ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Invertivore
Feeding is the process by which organisms, typically animals, obtain food. Terminology often uses either the suffixes -vore, -vory, or -vorous from Latin ''vorare'', meaning "to devour", or -phage, -phagy, or -phagous from Greek φαγεῖν (), meaning "to eat". Evolutionary history The evolution of feeding is varied with some feeding strategies evolving several times in independent lineages. In terrestrial vertebrates, the earliest forms were large amphibious piscivores 400 million years ago. While amphibians continued to feed on fish and later insects, reptiles began exploring two new food types, other tetrapods (carnivory), and later, plants (herbivory). Carnivory was a natural transition from insectivory for medium and large tetrapods, requiring minimal adaptation (in contrast, a complex set of adaptations was necessary for feeding on highly fibrous plant materials). Evolutionary adaptations The specialization of organisms towards specific food sources is one of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbidity
Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality. Fluids can contain suspended solid matter consisting of particles of many different sizes. While some suspended material will be large enough and heavy enough to settle rapidly to the bottom of the container if a liquid sample is left to stand (the settable solids), very small particles will settle only very slowly or not at all if the sample is regularly agitated or the particles are colloidal. These small solid particles cause the liquid to appear turbid. Turbidity (or haze) is also applied to transparent solids such as glass or plastic. In plastic production, haze is defined as the percentage of light that is deflected more than 2.5° from the incoming light direction. Causes and effects Turbidity in open water may be caused by growth of phyto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lotic
River ecosystems are flowing waters that drain the landscape, and include the Biotic component, biotic (living) interactions amongst plants, animals and micro-organisms, as well as abiotic (nonliving) physical and chemical interactions of its many parts.Angelier, E. 2003. Ecology of Streams and Rivers. Science Publishers, Inc., Enfield. Pp. 215.”Biology Concepts & Connections Sixth Edition”, Campbell, Neil A. (2009), page 2, 3 and G-9. Retrieved 2010-06-14. River Ecosystem, ecosystems are part of larger Drainage basin, watershed networks or catchments, where smaller headwater streams drain into mid-size streams, which progressively drain into larger river networks. The major zones in river ecosystems are determined by the river bed's gradient or by the velocity of the current. Faster moving turbulent water typically contains greater concentrations of Oxygen saturation, dissolved oxygen, which supports greater biodiversity than the slow-moving water of pools. These distinctio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pectoral Fins
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as seen in sharks. Apart from the tail or caudal fin, fish fins have no direct connection with the spine and are supported only by muscles. Their principal function is to help the fish swim. Fins located in different places on the fish serve different purposes such as moving forward, turning, keeping an upright position or stopping. Most fish use fins when swimming, flying fish use pectoral fins for gliding, and frogfish use them for crawling. Fins can also be used for other purposes; male sharks and mosquitofish use a modified fin to deliver sperm, thresher sharks use their caudal fin to stun prey, reef stonefish have spines in their dorsal fins that inject venom, anglerfish use the first spine of their dorsal fin like a fishing rod to lu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Substratum
In linguistics, a stratum (Latin for "layer") or strate is a language that influences or is influenced by another through contact. A substratum or substrate is a language that has lower power or prestige than another, while a superstratum or superstrate is the language that has higher power or prestige. Both substratum and superstratum languages influence each other, but in different ways. An adstratum or adstrate is a language that is in contact with another language in a neighbor population without having identifiably higher or lower prestige. The notion of "strata" was first developed by the Italian linguist Graziadio Isaia Ascoli (1829–1907), and became known in the English-speaking world through the work of two different authors in 1932. Thus, both concepts apply to a situation where an intrusive language establishes itself in the territory of another, typically as the result of migration. Whether the superstratum case (the local language persists and the intrusive languag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Riffles
A riffle is a shallow landform in a flowing channel. Colloquially, it is a shallow place in a river where water flows quickly past rocks. However, in geology a riffle has specific characteristics. Topographic, sedimentary and hydraulic indicators Riffles are almost always found to have a very low discharge compared to the flow that fills the channel (approximately 10–20%), and as a result the water moving over a riffle appears shallow and fast, with a wavy, disturbed water surface. The water's surface over a riffle at low flow also has a much steeper slope than that over other in-channel landforms. Channel sections with a mean water surface slope of roughly 0.1 to 0.5% exhibit riffles, though they can occur in steeper or gentler sloping channels with coarser or finer bed materials, respectively. Except in the period after a flood (when fresh material is deposited on a riffle), the sediment on the riverbed in a riffle is usually much coarser than on that in any other in-chann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meander
A meander is one of a series of regular sinuous curves in the channel of a river or other watercourse. It is produced as a watercourse erodes the sediments of an outer, concave bank ( cut bank) and deposits sediments on an inner, convex bank which is typically a point bar. The result of this coupled erosion and sedimentation is the formation of a sinuous course as the channel migrates back and forth across the axis of a floodplain. The zone within which a meandering stream periodically shifts its channel is known as a meander belt. It typically ranges from 15 to 18 times the width of the channel. Over time, meanders migrate downstream, sometimes in such a short time as to create civil engineering challenges for local municipalities attempting to maintain stable roads and bridges.Neuendorf, K.K.E., J.P. Mehl Jr., and J.A. Jackson, J.A., eds. (2005) ''Glossary of Geology'' (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. Charlton, R., 2007. ''Fundamentals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tributaries
A tributary, or affluent, is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drainage basin of its surface water and groundwater, leading the water out into an ocean. The Irtysh is a chief tributary of the Ob river and is also the longest tributary river in the world with a length of . The Madeira River is the largest tributary river by volume in the world with an average discharge of . A confluence, where two or more bodies of water meet, usually refers to the joining of tributaries. The opposite to a tributary is a distributary, a river or stream that branches off from and flows away from the main stream. PhysicalGeography.net, Michael Pidwirny & Scott ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anal Fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as seen in sharks. Apart from the tail or caudal fin, fish fins have no direct connection with the spine and are supported only by muscles. Their principal function is to help the fish swim. Fins located in different places on the fish serve different purposes such as moving forward, turning, keeping an upright position or stopping. Most fish use fins when swimming, flying fish use pectoral fins for gliding, and frogfish use them for crawling. Fins can also be used for other purposes; male sharks and mosquitofish use a modified fin to deliver sperm, thresher sharks use their caudal fin to stun prey, reef stonefish have spines in their dorsal fins that inject venom, anglerfish use the first spine of their dorsal fin like a fishing rod to lu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorsal Fins
A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through convergent evolution they have independently evolved external superficial fish-like body plans adapted to their marine environments, including most numerously fish, but also mammals such as cetaceans (whales, dolphins, and porpoises), and even extinct ancient marine reptiles such as various known species of ichthyosaurs. Most species have only one dorsal fin, but some have two or three. Wildlife biologists often use the distinctive nicks and wear patterns which develop on the dorsal fins of large cetaceans to identify individuals in the field. The bony or cartilaginous bones that support the base of the dorsal fin in fish are called ''pterygiophores''. Functions The main purpose of the dorsal fin is to stabilize the animal against rolling an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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