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Polyodon
The American paddlefish (''Polyodon spathula,'' also known as a Mississippi paddlefish, spoon-billed cat, or spoonbill) is a species of ray-finned fish. It is the only extant taxon, living species of paddlefish (Polyodontidae). This family is most closely related to the sturgeons; together they make up the order (biology), order Acipenseriformes, which are one of the most Basal (phylogenetics), primitive living groups of ray-finned fish. Fossil records of other paddlefish species date back 125 million years to the Early Cretaceous, with records of ''Polyodon'' extending back 65 million years to the early Paleocene. The American paddlefish is a smooth-skinned freshwater fish with an almost entirely cartilage, cartilaginous skeleton and a paddle-shaped rostrum (anatomy), rostrum (snout), which extends nearly one-third its body length. It has been referred to as a freshwater shark because of its heterocercal tail or caudal fin resembling that of sharks, though it is not closely rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paddlefish
Paddlefish (family Polyodontidae) are a family of ray-finned fish belonging to order Acipenseriformes, and one of two living groups of the order alongside sturgeons (Acipenseridae). They are distinguished from other fish by their titular elonglated rostrums, which are thought to enhance electroreception to detect prey. Paddlefish have been referred to as "primitive fish" because Acipenseriformes are amongst the earliest diverging lineages of ray-finned fish, having diverged from all other living groups over 300 million years ago. Paddlefish are almost exclusively North American and Chinese, both extant and in the fossil record. There are six known species: four extinct species known only from fossil remains (three from western North America, one from China), one extant species, the American paddlefish (''Polyodon spathula'') which is native to the Mississippi River basin in the U.S., and the Chinese paddlefish (''Psephurus gladius''), declared extinct in 2022 following a 2019 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinese Paddlefish
The Chinese paddlefish (''Psephurus gladius''; : literal translation: "white sturgeon"), also known as the Chinese swordfish, is an Extinction, extinct species of fish that was formerly native to the Yangtze and Yellow River basins in China. With records of specimens over and possibly in length, it was one of the largest species of Fresh water, freshwater fish. It was the only species in the genus ''Psephurus'' and one of two Holocene, recent species of paddlefish (Polyodontidae), the other being the American paddlefish (''Polyodon spathula''). It was an anadromous species, meaning that it spent part of its adult life at sea, while migrating upriver to Spawn (biology), spawn. The Chinese paddlefish was officially declared extinct in 2022, with an estimated time of extinction to be by 2005, and no later than 2010, although it had become functionally extinct by 1993. The main cause of its extinction was the construction of the Gezhouba Dam, Gezhouba and Three Gorges Dam, Three Go ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acipenseriformes
Acipenseriformes is an order of basal ray-finned fishes that includes living and fossil sturgeons and paddlefishes (Acipenseroidei), as well as the extinct families Chondrosteidae and Peipiaosteidae. They are the second earliest diverging group of living ray-finned fish after the bichirs. Despite being early diverging, they are highly derived, having only weakly ossified skeletons that are mostly made of cartilage, and in modern representatives highly modified skulls. Description The axial skeleton of Acipenseriformes is only partially ossified, with the majority of the bones being replaced with cartilage. The notochord, usually only found in fish embryos, is unconstricted and retained throughout life. The premaxilla and maxilla bones of the skull present in other vertebrates have been lost. The infraorbital nerve is carried by a series of separate canals, rather than being within the circumorbital bones. The palatoquadrate bones of the skull possess a cartilagi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sturgeon
Sturgeon is the common name for the 27 species of fish belonging to the family Acipenseridae. The earliest sturgeon fossils date to the Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ..., and are descended from other, earlier Acipenseriformes, acipenseriform fish, which date back to the Early Jurassic period, some 174 to 201 million years ago. They are one of two living families of the Acipenseriformes alongside paddlefish (Polyodontidae). The family is grouped into four genera: ''Acipenser'' (which is paraphyletic, containing many distantly related sturgeon species), ''Huso'', ''Scaphirhynchus,'' and ''Pseudoscaphirhynchus''. Two species (''Adriatic sturgeon, A. naccarii'' and ''Dabry's sturgeon, A. dabryanus'') may be extinct in the wild, and one (''Syr Darya s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rostrum (anatomy)
Rostrum (from Latin ', meaning ''beak'') is a term used in anatomy for a number of phylogenetically unrelated structures in different groups of animals. Invertebrates * In crustaceans, the rostrum is the forward extension of the carapace in front of the eyes. It is generally a rigid structure, but can be connected by a hinged joint, as seen in Leptostraca. * Among insects, the rostrum is the name for the piercing mouthparts of the order Hemiptera as well as those of the snow scorpionflies, among many others. The long snout of weevils is also called a rostrum. * Gastropod molluscs have a rostrum or proboscis. * Cephalopod molluscs have hard beak-like mouthparts referred to as the rostrum. File:Washington DC Zoo - Macrobrachium rosenbergii 6.jpg, Crustacean: the rostrum of the shrimp ''Macrobrachium rosenbergii'' is serrated along both edges. File:Gminatus australis with Beetle.jpg, Insect: assassin bug piercing its prey with its rostrum File:Architeuthis beak.jpg, Cephalopod: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxbow Lake
An oxbow lake is a U-shaped lake or pool that forms when a wide meander of a river is cut off, creating a free-standing body of water. In South Texas, oxbows left by the Rio Grande are called '' resacas''. In Australia, oxbow lakes are called billabongs. The word "oxbow" can also refer to a U-shaped bend in a river or stream, whether or not it is cut off from the main stream. Geology An oxbow lake forms when a meandering river erodes through the neck of one of its meanders. This takes place because meanders tend to grow and become more curved over time. The river then follows a shorter course that bypasses the meander. The entrances to the abandoned meander eventually silt up, forming an oxbow lake. Because oxbow lakes are stillwater lakes, with no current flowing through them, the entire lake gradually silts up, becoming a bog or swamp and then evaporating completely. When a river reaches a low-lying plain, often in its final course to the sea or a lake, it meanders wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yangtze River
The Yangtze or Yangzi ( or ; ) is the longest list of rivers of Asia, river in Asia, the list of rivers by length, third-longest in the world, and the longest in the world to flow entirely within one country. It rises at Jari Hill in the Tanggula Mountains (Tibetan Plateau) and flows in a generally easterly direction to the East China Sea. It is the List of rivers by discharge, seventh-largest river by discharge volume in the world. Its drainage basin comprises one-fifth of the land area of China, and is home to nearly one-third of the demographics of China, country's population. The Yangtze has played a major role in the history of China, history, culture of China, culture, and economy of China. For thousands of years, the river has been used for water, irrigation, sanitation, transportation, industry, boundary-marking, and war. The prosperous Yangtze Delta generates as much as 20% of historical GDP of China, China's GDP. The Three Gorges Dam on the Yangtze is the list ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mississippi River
The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it flows generally south for to the Mississippi River Delta in the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains all or parts of 32 U.S. states and two Canadian provinces between the Rocky and Appalachian mountains. The main stem is entirely within the United States; the total drainage basin is , of which only about one percent is in Canada. The Mississippi ranks as the thirteenth-largest river by discharge in the world. The river either borders or passes through the states of Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana. Native Americans have lived along the Mississippi River and its tributaries for thousands of years. Most were hunter-ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Braided River
A braided river, or braided channel, consists of a network of river channels separated by small, often temporary, islands called braid bars or, in English usage, ''aits'' or ''eyots''. Braided streams tend to occur in rivers with high sediment loads or coarse grain sizes, and in rivers with steeper slopes than typical rivers with straight or meandering channel patterns. They are also associated with rivers with rapid and frequent variation in the amount of water they carry, i.e., with "flashy" rivers, and with rivers with weak banks. Braided channels are found in a variety of environments all over the world, including gravelly mountain streams, sand bed rivers, on alluvial fans, on river deltas, and across depositional plains. Description A braided river consists of a network of multiple shallow channels that diverge and rejoin around ephemeral ''braid bars''. This gives the river a fancied resemblance to the interweaved strands of a braid. The braid bars, also known as channel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bernard Germain De Lacépède
Bernard-Germain-Étienne de La Ville-sur-Illon, comte de Lacépède or La Cépède (; 26 December 17566 October 1825) was a French naturalist and an active freemason. He is known for his contribution to the Comte de Buffon's great work, the ''Histoire Naturelle''. Biography Lacépède was born at Agen in Guienne. His education was carefully conducted by his father, and the early perusal of Buffon's Natural History ('' Histoire naturelle, générale et particulière'') awakened his interest in that branch of study, which absorbed his chief attention. His leisure he devoted to music, in which, besides becoming a good performer on the piano and organ, he acquired considerable mastery of composition, two of his operas (which were never published) meeting with the high approval of Gluck; in 1781–1785 he also brought out in two volumes his ''Poétique de la musique''. Meantime he wrote two treatises, ''Essai sur l'électricité'' (1781) and ''Physique générale et particuliè ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gulf Coast Of The United States
The Gulf Coast of the United States, also known as the Gulf South, is the coastline along the Southern United States where they meet the Gulf of Mexico. The coastal states that have a shoreline on the Gulf of Mexico are Texas, Louisiana, Mississippi, Alabama, and Florida, and these are known as the ''Gulf States''. The economy of the Gulf Coast area is dominated by industries related to energy, petrochemicals, fishing, aerospace, agriculture, and tourism. The large cities of the region are (from west to east) Brownsville, Corpus Christi, Houston, Galveston, Beaumont, Lake Charles, Lafayette, Baton Rouge, New Orleans, Gulfport, Biloxi, Mobile, Pensacola, Navarre, St. Petersburg, and Tampa. All are the centers or major cities of their respective metropolitan areas and many of which contain large ports. Geography The Gulf Coast is made of many inlets, bays, and lagoons. The coast is intersected by numerous rivers, the largest of which is the Mississippi River. Much of the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filter Feeder
Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feeding are clams, krill, sponges, baleen whales, and many fish (including some sharks). Some birds, such as flamingos and certain species of duck, are also filter feeders. Filter feeders can play an important role in clarifying water, and are therefore considered ecosystem engineers. They are also important in bioaccumulation and, as a result, as indicator organisms. Fish Most forage fish are filter feeders. For example, the Atlantic menhaden, a type of herring, lives on plankton caught in midwater. Adult menhaden can filter up to four gallons of water a minute and play an important role in clarifying ocean water. They are also a natural check to the deadly red tide. Extensive article on the role of menhaden in the ecosystem and possible resul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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