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Osteoglossiform
Osteoglossiformes , meaning "bony tongues" in Ancient Greek, is a relatively primitive order (biology), order of ray-finned fish that contains two sub-orders, the Osteoglossoidei and the Notopteroidei. All of at least 245 living species inhabit freshwater. They are found in South America, Africa, Australia and southern Asia, having first evolved in Gondwana before that continent broke up. In 2008, several new species of marine life, marine osteoglossiforms were described from the Danish Eocene Fur Formation, dramatically increasing the diversity of this group. This implies that the Osteoglossomorpha is not a primary freshwater fish group with the osteoglossiforms having a typical Gondwana distribution. The Gymnarchidae (the only species being ''Gymnarchus niloticus'', the African knifefish) and the Mormyridae are weakly electric fish able to sense their prey using electric fields. The mooneyes (Hiodontidae) are often classified here, but may also be placed in a separate order, Hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteoglossidae
Osteoglossidae is a family of large-sized freshwater fish, which includes the arowanas. They are commonly known as bonytongues. The family has been regarded as containing two extant subfamilies Arapaiminae and Osteoglossinae, with a total of five living genera, but these are regarded as valid families in '' Eschmeyer's Catalog of Fishes'' The extinct Phareodontinae are known from worldwide during the Late Cretaceous and Paleogene; they are generally considered to be crown group osteoglossids that are more closely related to one of the extant osteoglossid subfamilies than the other, though their exact position varies. Evolution Osteoglossids are basal teleosts that originated during the Cretaceous, and are placed in the actinopterygian order Osteoglossiformes. The traditionally defined wider family includes several extant species from South America, one from Africa, two from Asia, and two from Australia. The earliest known osteoglossid is '' Cretophareodus'' from the mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pantodontidae
Pantodontidae is a Family (biology), family of ray-finned fish in the order Osteoglossiformes. It contains the living freshwater butterflyfish (''Pantodon buchholzi'') of Africa, as well as several extinct marine species from the Late Cretaceous (Cenomanian) of the Sannine Formation in Lebanon. Taxonomy The Cretaceous marine pantodontids are among the earliest known marine Osteoglossomorpha, osteoglossomorph genera. They physically differ greatly from ''Pantodon'', to the extent that some of them were previously considered either ancestral Codlet, codlets or crestfish, but they all share specific cranial elements with the extant ''Pantodon'', supporting their relationship to it. They seem to form a grade leading to the extant ''Freshwater butterflyfish, Pantodon'', where ''Capassopiscis'' appears to be the most Basal (phylogenetics), basal genus, while ''Palaeopantodon'' appears to be the Sister group, sister genus to ''Pantodon'', with the rest occupying successive positions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Notopteridae
The family Notopteridae contains 11 species of osteoglossiform (bony-tongued) fishes, commonly known as featherbacks and knifefishes. These fishes live in freshwater or brackish environments in Africa and West, South, East and Southeast Asia. With the denotation of "knifefish", the notopterids should not be confused with Gymnotiformes, the electric knifefishes from South and Central America. Although their manner of swimming is similar and they are superficially similar in appearance, the two groups are not closely related. A few of the larger species, especially ''Chitala ornata'', are food fish and occasionally aquarium pets. The name is from Greek ''noton'' meaning "back" and ''pteron'' meaning "fin". Fossils The earliest fossil of this family is otolith of '' Notopteridarum'' from the Late Cretaceous of India, about 70.6 to 66 million years ago. Description Featherbacks have slender, elongated, bodies, giving them a knife-like appearance. The caudal fin is small and fus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fur Formation
The Fur Formation is a marine geological formation of Ypresian ( Lower Eocene Epoch, c. 56.0-54.5 Ma) age which crops out in the Limfjord region of northern Denmark from Silstrup via Mors and Fur to Ertebølle, and can be seen in many cliffs and quarries in the area. The Diatomite Cliffs (''moler'' in Danish) is on the Danish list of tentative candidates for World Heritage and may become a World Heritage site. Fossils found in the Fur Formation are primarily housed at the Fossil and Mo-clay Museum on Mors Island, the Fur Museum on Fur Island, and the Natural History Museum of Denmark (formerly named Geological Museum) in Copenhagen. Geology The Fur Formation is a unit of diatomitic sediment approximately 60 meters thick consisting of diatoms and clay minerals with up to 180 layers of volcanic ash. In Danish literature the formation has informally been referred to as the ''moler'' (''Ler'' means clay). The diatomite comprises 2/3 opal tests of diatoms and 1/3 clay, interbedded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteoglossum Bicirrhosum
The silver arowana (''Osteoglossum bicirrhosum'') is a South American freshwater bony fish of the family Osteoglossidae. Silver arowanas are sometimes kept in aquariums, but they are predatory and require a very large tank. The generic name ''Osteoglossum'' means "bone-tongued" and the specific name ''bicirrhosum'' means "two barbels" (from the Greek language). Range and habitat This South American species is native to the Amazon, Essequibo and Oyapock basins. It is absent from the Rio Negro basin, except the Branco River, which is inhabited by both silver and black arowanas. The silver arowana occurs in both black- and whitewater habitats, including flooded forests. Description This fish has relatively large scales, a long body, and a tapered tail, with the dorsal and anal fins extending all the way to the small caudal fin, with which they are nearly fused. Its maximum total length is typically considered to be , but there are reports of individuals up to . Unlike the bla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primary Freshwater Fish
Freshwater fish are fish species that spend some or all of their lives in bodies of fresh water such as rivers, lakes, ponds and inland wetlands, where the salinity is less than 1.05%. These environments differ from marine habitats in many ways, especially the difference in levels of osmolarity. To survive in fresh water, fish need a range of physiological adaptations. 41.24% of all known species of fish are found in fresh water. This is primarily due to the rapid speciation that the scattered habitats make possible. When dealing with ponds and lakes, one might use the same basic models of speciation as when studying island biogeography. Physiology Freshwater fish differ physiologically from saltwater fish in several respects. Their gills must be able to diffuse dissolved gases while keeping the electrolytes in the body fluids inside. Their scales reduce water diffusion through the skin: freshwater fish that have suffered too much scale loss will die. They also have well-deve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gondwana
Gondwana ( ; ) was a large landmass, sometimes referred to as a supercontinent. The remnants of Gondwana make up around two-thirds of today's continental area, including South America, Africa, Antarctica, Australia (continent), Australia, Zealandia, Arabian Peninsula, Arabia, and the Indian subcontinent. Gondwana was formed by the Accretion (geology), accretion of several cratons (large stable blocks of the Earth's crust), beginning with the East African Orogeny, the collision of India and Geography of Madagascar, Madagascar with East Africa, and culminating in with the overlapping Brasiliano orogeny, Brasiliano and Kuunga orogeny, Kuunga orogenies, the collision of South America with Africa, and the addition of Australia and Antarctica, respectively. Eventually, Gondwana became the largest piece of continental crust of the Paleozoic Era, covering an area of some , about one-fifth of the Earth's surface. It fused with Laurasia during the Carboniferous to form Pan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Life
Marine life, sea life or ocean life is the collective ecological communities that encompass all aquatic animals, aquatic plant, plants, algae, marine fungi, fungi, marine protists, protists, single-celled marine microorganisms, microorganisms and associated marine virus, viruses living in the saline water of marine habitats, either the sea water of marginal seas and oceans, or the brackish water of coastal wetlands, lagoons, estuary, estuaries and inland seas. , more than 242,000 marine species have been documented, and perhaps two million marine species are yet to be documented. An average of 2,332 new species per year are being described. Marine life is studied scientifically in both marine biology and in biological oceanography. By volume, oceans provide about 90% of the living space on Earth, and served as the cradle of life and vital biotic sanctuaries throughout Earth's geological history. The earliest known life forms evolved as anaerobe, anaerobic prokaryotes (archaea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes from the Ancient Greek (''Ēṓs'', 'Eos, Dawn') and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch.See: *Letter from William Whewell to Charles Lyell dated 31 January 1831 in: * From p. 55: "The period next antecedent we shall call Eocene, from ήως, aurora, and χαινος, recens, because the extremely small proportion of living species contained in these strata, indicates what may be considered the first commencement, or ''dawn'', of the existing state of the animate creation." The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isoto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weakly Electric Fish
An electric fish is any fish that can Bioelectrogenesis, generate electric fields, whether to sense things around them, for defence, or to stun prey. Most fish able to produce shocks are also electroreceptive, meaning that they can sense electric fields. The only exception is the Uranoscopidae, stargazer family (Uranoscopidae). Electric fish, although a small minority of all fishes, include both oceanic and freshwater species, and both cartilaginous and bony fishes. Electric fish produce their electrical fields from an Electric organ (biology), electric organ. This is made up of electrocytes, modified muscle or nerve cells, specialized for producing strong electric fields, used to locate prey, for Anti-predator adaptation, defence against predators, and for Signalling theory, signalling, such as in courtship. Electric organ discharges are two types, pulse and wave, and vary both by species and by function. Electric fish have evolved many specialised behaviours. The predatory Cla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gymnarchus Niloticus
The African knifefish, ''Gymnarchus niloticus'' – also called the ''aba aba'' – is an electric fish, living at the bottoms of rivers and lakes. It is the only species in the genus ''Gymnarchus'' and the family Gymnarchidae, within the order Osteoglossiformes. It is a long slender fish with no pelvic or anal fins, and a tail fin shaped like a rat's tail. It swims using its elongated dorsal fin, allowing it to keep its body straight while it moves. This in turn enables it to produce a steady but weak electric field, which it uses to locate its prey. It is large for a river fish; adults can reach 1.6 m (5.2 ft) in length and 19 kg (42 lb) in weight. In 1950, Hans Lissmann noticed that the fish could swim equally well forwards or backwards, clearly relying on a sense other than vision. He demonstrated that it could locate prey by electroreception, making it the first fish known to have this ability. The fish is considered good to eat in West Africa, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Order (biology)
Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. An immediately higher rank, superorder, is sometimes added directly above order, with suborder directly beneath order. An order can also be defined as a group of related families. What does and does not belong to each order is determined by a taxonomist, as is whether a particular order should be recognized at all. Often there is no exact agreement, with different taxonomists each taking a different position. There are no hard rules that a taxonomist needs to follow in describing or recognizing an order. Some taxa are accepted almost universally, while others are recognized only rarely. The name of an order is usually written with a capital letter. For some groups of organisms, their orders may follow consist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
