|
Eobothus
''Eobothus'' ('Dawn flounder') is an extinct genus of flatfish from the Eocene epoch of China, India and Europe. ''Eobothus'' is significant as one of the earliest genera of flatfish, one of the last major fish groups to evolve. It closely resembled modern flatfish, with an oval-shaped body about long, surrounded by elongated dorsal and anal fins. In the adult, the eyes were both located on the left side of the head, as in modern species, and the fish would have lain flat against the seafloor on its right side. This was an evolutionary advance from still earlier flatfish, such as ''Heteronectes ''Heteronectes chaneti'' is a fossil fish which has been identified as a primitive flatfish, dating to the early Eocene (Lutetian stage) of France. ''Heteronectes'' is reported to be a transitional fossil. In a typical modern flatfish, the head ...'', in which the eyes only partially migrated. References Eocene fish of Asia Eocene fish of Europe Pleuronectiformes Prehistori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flatfish
A flatfish is a member of the Ray-finned fish, ray-finned demersal fish order (biology), order Pleuronectiformes, also called the Heterosomata, sometimes classified as a suborder of Perciformes. In many species, both eyes lie on one side of the head, one or the other migrating through or around the head during development. Some species face their left sides upward, some face their right sides upward, and others face either side upward. Many important food fish are in this order, including the flounders, sole (fish), soles, turbot, plaice, and halibut. Some flatfish can camouflage themselves on the ocean floor. Taxonomy Over 800 described species are placed into 16 families. Broadly, the flatfishes are divided into two suborders, Psettodoidei and Pleuronectoidei, with > 99% of the species diversity found within the Pleuronectoidei. The largest families are Soleidae, Bothidae and Tonguefish, Cynoglossidae with more than 150 species each. There also exist two monotypic families (P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleuronectiformes
A flatfish is a member of the ray-finned demersal fish order Pleuronectiformes, also called the Heterosomata, sometimes classified as a suborder of Perciformes. In many species, both eyes lie on one side of the head, one or the other migrating through or around the head during development. Some species face their left sides upward, some face their right sides upward, and others face either side upward. Many important food fish are in this order, including the flounders, soles, turbot, plaice, and halibut. Some flatfish can camouflage themselves on the ocean floor. Taxonomy Over 800 described species are placed into 16 families. Broadly, the flatfishes are divided into two suborders, Psettodoidei and Pleuronectoidei, with > 99% of the species diversity found within the Pleuronectoidei. The largest families are Soleidae, Bothidae and Cynoglossidae with more than 150 species each. There also exist two monotypic families (Paralichthodidae and Oncopteridae). Some families are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flounder
Flounders are a group of flatfish species. They are demersal fish, found at the bottom of oceans around the world; some species will also enter estuaries. Taxonomy The name "flounder" is used for several only distantly related species, though all are in the suborder Pleuronectoidei (families Achiropsettidae, Bothidae, Pleuronectidae, Paralichthyidae, and Samaridae). Some of the better known species that are important in fisheries are: * Western Atlantic ** Gulf flounder – ''Paralichthys albigutta'' ** Southern flounder – ''Paralichthys lethostigma'' ** Summer flounder (also known as ''fluke'') – ''Paralichthys dentatus'' ** Winter flounder – ''Pseudopleuronectes americanus'' * European waters **European flounder – ''Platichthys flesus'' ** Witch flounder – ''Glyptocephalus cynoglossus'' * North Pacific ** Halibut – ''Hippoglossus stenolepis'' ** Olive flounder – ''Paralichthys olivaceus'' Eye migration Larval flounder are born with one eye on each side o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus comes above species and below family (taxonomy), family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). 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'', "dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. 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 isotope Carbon-13, 13C in the atmosphere was exceptionally low in comparison with the more common isotope Carbon-12, 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Popigai impact structure, Siberia and in what is now ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorsal Fin
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 rollin ... [...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] |
Heteronectes
''Heteronectes chaneti'' is a fossil fish which has been identified as a primitive flatfish, dating to the early Eocene (Lutetian stage) of France. ''Heteronectes'' is reported to be a transitional fossil. In a typical modern flatfish, the head is asymmetric with both eyes on one side of the head. In ''Heteronectes'', the transition from the typical symmetric head of a vertebrate is incomplete, with one eye positioned near the top of the head, very similar (but less so) to its Italian relative '' Amphistium''. The rest of the skeleton also has some primitive features in common with other Percomorph groups, but absent in living flatfishes.Friedman M (2008). “The evolutionary origin of flatfish asymmetry”, ''Nature'' 454(7201): p. 209-212: The condition in modern, bottom-dwelling flatfish with both eyes on the same side of the head was cited by St. George Jackson Mivart as difficult to imagine how it could have evolved in a gradual fashion by natural selection, as proposed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene Fish Of Asia
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. 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 isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. As with other geologic periods, the strata that define the start and end of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene Fish Of Europe
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. 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 isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. As with other geologic periods, the strata that define the start and end of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.png "Click for more on -> Anal Fin")
