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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 elongated rostra, which are thought to enhance electroreception to detect prey. Paddlefish have been referred to as " primitive fish" because the Acipenseriformes are among the earliest diverging lineages of ray-finned fish, having diverged from all other living groups over 300 million years ago. Both living and fossil paddlefish are found almost exclusively in North America and China. Eight species are known: Six of those species are extinct, and known only from fossils (five from North America, one from China), one of the extant species, the American paddlefish (''Polyodon spathula''), is native to the Mississippi River basin in the U.S. The other is the Chinese paddlefish (''Psephurus gladius''), which was declared extinct in 2022 following a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Paddlefish
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 last 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 rel ... [...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 List of largest fish, largest species of 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, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acipenseriformes
Acipenseriformes is an order (biology), order of basal (phylogenetics), basal Actinopterygii, ray-finned fishes that includes living and fossil sturgeons and paddlefishes (Acipenseroidei), as well as the extinct family (biology), 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 Primitive (phylogenetics), derived, having only weakly Ossification, 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. While larvae and early juvenile acipenseriforms have teeth, the adult ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yangtze River Basin
The Yangtze or Yangzi ( or ) is the longest river in Eurasia and the list of rivers by length, third-longest in the world. It rises at Jari Hill in the Tanggula Mountains of the Tibetan Plateau and flows including Dangqu, Dam Qu River the longest source of the Yangtze, in a generally easterly direction to the East China Sea. It is the List of rivers by discharge, fifth-largest primary 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 Yangtze Delta generates as much as 20% of historical GDP of China, China's GDP, and the Three Gorges Dam on the Yangtze is the list of largest hydroelec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protopsephurus
''Protopsephurus'' is an extinct genus of paddlefish containing the single species ''Protopsephurus liui,'' known from the Yixian, Jiufotang and Huajiying formations in Liaoning, northern China from the Barremian to Aptian ages of the Early Cretaceous period around 125-120 million years ago. It is currently the oldest and most basal paddlefish known. Description The species is known from numerous specimens ranging up to about long. The snout is shorter than that in any other known paddlefish, and is more sturgeon-like. The morphology of the skull roof is also more archaic than any other paddlefish. The axial skeleton is poorly ossified. Like other extinct polyodontids, it also has tiny non-interlocking scales approximately 1 mm in diameter called denticles that cover the trunk, which bear a fringe of spikes. Diet ''Protopsephurus'' is thought to have been piscivorous, feeding on smaller fish. One adult specimen of ''Protopsephurus'' has been observed with a specimen of '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ray-finned Fish
Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of skin supported by radially extended thin bony spines called '' lepidotrichia'', as opposed to the bulkier, fleshy lobed fins of the sister clade Sarcopterygii (lobe-finned fish). Resembling folding fans, the actinopterygian fins can easily change shape and wetted area, providing superior thrust-to-weight ratios per movement compared to sarcopterygian and chondrichthyian fins. The fin rays attach directly to the proximal or basal skeletal elements, the radials, which represent the articulation between these fins and the internal skeleton (e.g., pelvic and pectoral girdles). The vast majority of actinopterygians are teleosts. By species count, they dominate the subphylum Vertebrata, and constitute nearly 99% of the over 30,000 extant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parapsephurus
''Parapsephurus'' is an extinct genus of paddlefish in the family Polyodontidae. Currently the only known species in this genus is the type species, ''Parapsephurus willybemisi.'' ''P. willybemisi'' is known a nearly complete specimen from the Tanis locality of the Hell Creek Formation in North Dakota, USA, which dates to the late Maastrichtian stage of the Late Cretaceous, approximately 66 million years ago. The name ''Parapsephurus'' refers to the similarities between the short gill arches of this genus and the more recently extinct paddlefish '' Psephurus,'' also known as the Chinese paddlefish. The type species, ''P. willybemisi'', is named in honor of William E. Bemis, a professor of ecology and evolutionary biology and curator of fishes at Cornell University, who has conducted extensive research on paddlefish. The rostrum of the holotype specimen is around in length, with a total body length of around . The species is placed in the clade Polyodonti, which includes all pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crossopholis
''Crossopholis'' is an extinct fish known from the early Eocene (Ypresian) of North America, approximately 52 million years ago. It is a close relative of the contemporary American paddlefish, belonging to the paddlefish family Polyodontidae. History of discovery First described by Edward Drinker Cope in 1883, the first specimen consisted of an incomplete section of the fish's body and tail. In 1886, a partial skull was recovered by Cope. A nearly complete fossil wasn't recorded until 1980. This was due, in part, to the comparative rarity of the fossil as well as the similarities to other species found within the site. Classification A member of the family Polyodontidae, ''Crossopholis'' is most closely related to the American paddlefish. ''Crossopholis'' means "fringed scales"; a reference to the thousands of tiny (less than 0.5mm) scales which covered the body of the animal. Relationships of recent and fossil paddlefish genera, after Grande ''et al.'' (2002). Paleobiology T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleopsephurus
''Paleopsephurus'' is an extinct genus of paddlefish (Polyodontidae). At present the genus contains the single species ''Paleopsephurus wilsoni''. The genus is known from the Late Cretaceous (Maastrichtian) aged Hell Creek Formation of Montana. History and classification The genus was described from three partial specimens currently residing in the collections of the University of Michigan Museum of Paleontology in Ann Arbor, Michigan, USA. Specimen number '' 22206 U.M.'' is a complete and well preserved skull with some denticles, pectoral girdle and pectoral fins. The second and third specimens were found in a block of matrix from the same location as ''2226 U.M.''. Specimen ''22207 U.M.'' is a portion of the caudal region of a paddlefish, while ''22208 U.M.'' is a partial shoulder with associated pectoral fin. While the specimens were found close to each other, it is impossible to determine if they represent a single individual, and as such were described as three separ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mississippi River
The Mississippi River is the main stem, primary river of the largest drainage basin in the United States. It is the second-longest river in the United States, behind only the Missouri River, Missouri. 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 Drainage basin, watershed drains all or parts of 32 U.S. states and two Canadian provinces between the Rocky Mountains, Rocky and Appalachian Mountains, Appalachian mountains. The river either borders or passes through the states of Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana. 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 world's List of rivers by discharge, tenth-largest river by discharge flow, and the largest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sturgeon
Sturgeon (from Old English ultimately from Proto-Indo-European language, Proto-Indo-European *''str̥(Hx)yón''-) is the common name for the 27 species of fish belonging to the family Acipenseridae. The earliest sturgeon fossils date to the Late Cretaceous, 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 five genera: ''Acipenser'', ''Huso'', ''Scaphirhynchus,'' ''Sinosturio'', and ''Pseudoscaphirhynchus''. Two species (''Adriatic sturgeon, H. naccarii'' and ''Dabry's sturgeon, S. dabryanus'') may be extinct in the wild, and one (''Syr Darya sturgeon, P. fedtschenkoi'') may be entirely extinct. Sturgeons are native to subtropical, temperate and sub-Arctic rivers, lakes and coastlines of Eurasia and North America. A Maastrichtian-age fossil found i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electroreception
Electroreception and electrogenesis are the closely related biological abilities to perceive electrical stimuli and to generate electric fields. Both are used to locate prey; stronger electric discharges are used in a few groups of fishes, such as the electric eel, to stun prey. The capabilities are found almost exclusively in aquatic or amphibious animals, since water is a much better Conductor (material), conductor of electricity than air. In passive electrolocation, objects such as prey are detected by sensing the electric fields they create. In active electrolocation, fish generate a weak electric field and sense the different distortions of that field created by objects that conduct or resist electricity. Active electrolocation is practised by two groups of weakly electric fish, the order Gymnotiformes (knifefishes) and family Mormyridae (elephantfishes), and by the monotypic genus ''Gymnarchus'' (African knifefish). An electric fish generates an electric field using an Elect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
