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Livebearer
Livebearers are fish that retain their eggs inside the body and give birth to live, free-swimming young. They are especially prized by aquarium owners. Among aquarium fish, livebearers are nearly all members of the family Poeciliidae and include: guppy, molly, platy, endler’s and swordtails. The advantages of livebearing to the aquarist are that the newborn juvenile fish are larger than newly-hatched fry, have a lower chance of mortality and are easier to care for. Unusual livebearers include seahorses and pipefish, where the males care for the young, and certain cichlids that are mouthbrooders, with the parent incubating the eggs in the buccal cavity. Common aquarium livebearers Species of interest to aquarists are almost always members of the family Poeciliidae, most commonly guppies, mollies, platies, swordtails, Endler's livebearer, and mosquitofish. Most of these are ovoviviparous, with the developing embryos receiving no nourishment from the parent fish, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poecilia Wingei
''Poecilia wingei'', known to aquarists as Endlers or Endler's livebearer, in the genus ''Poecilia'', is a small fish native to the Paria Peninsula in Venezuela. They are prolific breeders and often hybridize with guppy, guppies. These very colorful hybrids are the easiest to find being offered in pet-shops, typically under the name Endler's guppy. History ''Poecilia wingei'' is a very colorful guppy species, similar to the fancy guppy often found in pet shops. The species was first collected from Laguna de Patos in Venezuela by Franklyn F. Bond in 1937, and rediscovered by Dr. John Endler in 1975. The latter were the first examples of this fish to make it to the aquarium trade. More have been collected since then, notably by Armando Pou, to expand the captive breeding stock. The original Laguna de Patos population is threatened by runoff from a municipal garbage dump. Though it is rare in Pet store, pet shops, this species is seen occasionally in the aquaria of enthusiasts. In 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poecilia Reticulata Fry DSC04357 Nevit
''Poecilia'' is a genus of fishes in the family Poeciliidae of the order Cyprinodontiformes. These livebearers are native to fresh, brackish water, brackish and salt water in the Americas, and some species in the genus are euryhaline. A few have adapted to living in waters that contain high levels of toxic hydrogen sulfide () and a population of ''Poecilia mexicana, P. mexicana'' lives Cavefish, in caves (other populations of this species are surface-living). Some common and widespread species are often kept as live-bearing aquarium fish, aquarium fish, while other have very small ranges and are seriously Threatened species, threatened. Species in ''Poecilia'' are called ''mollies'' (e. g. ''Poecilia sphenops, P. sphenops'') or ''guppies'' (e. g. ''Poecilia reticulata, P. reticulata'') depending on body shape. ''Micropoecilia'' has been proposed to be included as a subgenus of ''Poecilia''. Taxonomy and etymology ''Poecilia'' was first proposed as a genus in 1801 by the German n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platies
Platy is a common name of freshwater fish in the genus ''Xiphophorus'' that lack a "sword" at the bottom of their tails. This species is a livebearer, similar to other fish of the family Poeciliidae, such as the guppy and molly. Platies are native to the east coast of Central America and southern Mexico. The two species, the southern platyfish and the variatus platy, have been interbred to the point where they are difficult to distinguish. Most platies now sold in aquariums are hybrids of both species. Platy The platy (''Xiphophorus maculatus'') grows to a maximum overall length of . Sexual dimorphism is slight, the male's caudal fin being more pointed. The anal fin of the male fish has evolved into a gonopodium, a stick-shaped organ used for reproduction. The female southern platyfish's anal fin is fan-shaped. Wild varieties are drab in coloration, lacking the distinctive dark lateral line common to many ''Xiphophorus'' species. Platies can have from 20–50 fry (baby f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platy (fish)
Platy is a common name of freshwater fish, freshwater fish in the genus ''Xiphophorus'' that lack a "sword" at the bottom of their tails. This species is a Live-bearing aquarium fish, livebearer, similar to other fish of the family Poeciliidae, such as the guppy and Poecilia, molly. Platies are native to the east coast of Central America and southern Mexico. The two species, the southern platyfish and the variatus platy, have been interbred to the point where they are difficult to distinguish. Most platies now sold in aquariums are hybrids of both species. Platy The platy (''Xiphophorus maculatus'') grows to a maximum overall length of . Sexual dimorphism is slight, the male's caudal fin being more pointed. The anal fin of the male fish has evolved into a gonopodium, a stick-shaped organ used for reproduction. The female southern platyfish's anal fin is fan-shaped. Wild varieties are drab in coloration, lacking the distinctive dark lateral line common to many ''Xiphophorus'' spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swordtail
''Xiphophorus'' is a genus of euryhaline and freshwater fishes in the family Poeciliidae of order Cyprinodontiformes, native to Mexico and northern Central America. ''Xiphophorus'' species can be divided into three groups based on their evolutionary relationships: platyfish (or platies), northern swordtails, and southern swordtails. Platyfish formerly were classified in another genus, ''Platypoecilus'', which is now obsolete. The type species is ''X. hellerii,'' the green swordtail. Like most other new world Poeciliids, platies and swordtails are live-bearers that use internal fertilization and give birth to live young instead of laying eggs like the bulk of the world's fishes. The name ''Xiphophorus'' derives from the Greek words ξίφος (dagger) and φόρος (bearer), referring to the gonopodium on the males. All are relatively small fishes, which reach a maximum length of depending on the exact species involved. Distribution and conservation status The various ''Xi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xiphophorus
''Xiphophorus'' is a genus of euryhaline and freshwater fishes in the family Poeciliidae of order (biology), order Cyprinodontiformes, native to Mexico and northern Central America. ''Xiphophorus'' species can be divided into three groups based on their evolutionary relationships: platyfish (or platies), northern swordtails, and southern swordtails. Platyfish formerly were classified in another genus, ''Platypoecilus'', which is now obsolete. The type species is ''X. hellerii,'' the green swordtail. Like most other new world Poeciliids, platies and swordtails are Livebearers, live-bearers that use internal fertilization and give birth to live young instead of laying eggs like the bulk of the world's fishes. The name ''Xiphophorus'' derives from the Greek language, Greek words ξίφος (dagger) and φόρος (bearer), referring to the Fish fin#Reproduction, gonopodium on the males. All are relatively small fishes, which reach a maximum length of depending on the exact specie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fancy Molly
A fancy molly is any of the domestic strains of mollies (''Mollienesia'' subgenus of ''Poecilia''), which are livebearer fish popularly kept as aquarium pets. The origin of the fancy mollies is unclear, with '' P. sphenops'', '' P. gillii'', '' P. latipinna'', and '' P. velifera'' commonly named as parent species. Fancy mollies are widespread in pet stores across the world and commonly marketed as a good choice for aquarists, especially for beginners in the fishkeeping hobby. Origins Mollies entered the fishkeeping hobby around 1905. The identity of the species from which the fancy mollies originate is difficult to ascertain because early aquarists crossbred any mollies available to them. In 1969 Kurt Jacobs credited "Crescenty in New Orleans" with developing the black molly through seven years of selective breeding of "''Mollienesia formosa''" (today synonym for ''Poecilia formosa''). John A. Dawes considers it unlikely that the black molly is derived from ''P. formosa'' because ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homology (biology)
In biology, homology is similarity in anatomical structures or genes between organisms of different taxa due to shared ancestry, ''regardless'' of current functional differences. Evolutionary biology explains homologous structures as retained heredity from a common descent, common ancestor after having been subjected to adaptation (biology), adaptive modifications for different purposes as the result of natural selection. The term was first applied to biology in a non-evolutionary context by the anatomist Richard Owen in 1843. Homology was later explained by Charles Darwin's theory of evolution in 1859, but had been observed before this from Aristotle's biology onwards, and it was explicitly analysed by Pierre Belon in 1555. A common example of homologous structures is the forelimbs of vertebrates, where the bat wing development, wings of bats and origin of avian flight, birds, the arms of primates, the front flipper (anatomy), flippers of whales, and the forelegs of quadrupedalis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquariums
An aquarium (: aquariums or aquaria) is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. fishkeeping, Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aquatic reptiles, such as turtles, and aquatic plants. The term ''aquarium'', coined by English naturalist Philip Henry Gosse, combines the Latin root , meaning 'water', with the suffix , meaning 'a place for relating to'. The aquarium principle was fully developed in 1850 by the chemist Robert Warington, who explained that plants added to water in a container would give off enough oxygen to support animals, so long as the numbers of animals did not grow too large. The aquarium craze was launched in early Victorian era, Victorian England by Gosse, who created and stocked the first public aquarium at the London Zoo in 1853, and published the first manual, ''The Aquarium: An Unveiling of the Wonders of the Deep Sea'' in 1854. Small aquariums are k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seahorse
A seahorse (also written ''sea-horse'' and ''sea horse'') is any of 46 species of small marine Osteichthyes, bony fish in the genus ''Hippocampus''. The genus name comes from the Ancient Greek (), itself from () meaning "horse" and () meaning "sea monster" or "sea animal". Having a head and neck suggestive of a horse, seahorses also feature segmented bony armour, an upright posture and a curled prehensile tail. Along with the pipefishes and seadragons (''Phycodurus'' and ''Phyllopteryx'') they form the family Syngnathidae. Evolution and fossil record Anatomical evidence, supported by molecular, physical, and genetic evidence, demonstrates that seahorses are highly modified pipefish. The fossil record of seahorses, however, is very sparse. The best known and best studied fossils are specimens of ''Hippocampus guttulatus'' (though literature more commonly refers to them under the synonym of ''H. ramulosus''), from the Marecchia River formation of Rimini Province, Italy, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placental Mammals
Placental mammals ( infraclass Placentalia ) are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupialia. Placentalia contains the vast majority of extant mammals, which are partly distinguished from monotremes and marsupials in that the fetus is carried in the uterus of its mother to a relatively late stage of development. The name is something of a misnomer, considering that marsupials also nourish their fetuses via a placenta, though for a relatively briefer period, giving birth to less-developed young, which are then nurtured for a period inside the mother's pouch. Placentalia represents the only living group within Eutheria, which contains all mammals that are more closely related to placentals than they are to marsupials. Anatomical features Placental mammals are anatomically distinguished from other mammals by: * a sufficiently wide opening at the bottom of the pelvis to allow the birth of a large baby relative to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placenta
The placenta (: placentas or placentae) is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas, and waste exchange between the physically separate maternal and fetal circulations, and is an important endocrine organ, producing hormones that regulate both maternal and fetal physiology during pregnancy. The placenta connects to the fetus via the umbilical cord, and on the opposite aspect to the maternal uterus in a species-dependent manner. In humans, a thin layer of maternal decidual ( endometrial) tissue comes away with the placenta when it is expelled from the uterus following birth (sometimes incorrectly referred to as the 'maternal part' of the placenta). Placentas are a defining characteristic of placental mammals, but are also found in marsupials and some non-mammals with varying levels of development. Mammalian placentas probably first evolved abou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
