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Astyanax (fish)
''Astyanax'' is a genus of freshwater fish in the family (biology), family Acestrorhamphidae of the order (biology), order Characiformes. Some of these fish, like many of their relatives, are kept as aquarium pets and known collectively as tetras. With around 150 described species and new ones being described yearly, this genus is among the largest of the entire order; ''Hyphessobrycon'' also has more than 145 species and which one is larger at any one time depends on whether more species have been recently described in one or the other. The blind and colorless cave tetra of Mexico is a famous member of the genus, but its Taxonomy (biology), taxonomic position is disputed: Some recognize it as Mexican tetra#Blind cave form, part of the Mexican tetra (''A. mexicanus'') and this is supported by phylogenetic evidence, but others recognize the cave form as a separate species, ''Astyanax jordani, A. jordani''. The type species is ''A. argentatus'', now regarded as a form of the Mexican ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astyanax Mexicanus
The Mexican tetra (''Astyanax mexicanus''), also known as the blind cave fish, blind cave characin or the blind cave tetra, is a freshwater fish in the Characidae family (tetras and relatives) of the order Characiformes. The type species of its genus, it is native to the Nearctic realm, originating in the lower Rio Grande, and the Neueces and Pecos Rivers in Texas, into the Central Plateau and eastern states of Mexico. Maturing at a total length of about , the Mexican tetra is of typical characin form, albeit with silvery, unremarkable scalation, likely an evolutionary adaptation to its natural environment. By comparison, the species' blind "cave" form has scales which evolved a pale, pinkish-white color, somewhat resembling an albino, as it inhabits pitch-black caverns and subterranean streams and has no need for a colorful appearance (i.e. for attracting mates). Likewise, the blind cave tetra has fully "devolved" (lost) the use of its eyes by living in an environment compl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic
In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical data and observed heritable traits of DNA sequences, protein amino acid sequences, and morphology. The results are a phylogenetic tree—a diagram depicting the hypothetical relationships among the organisms, reflecting their inferred evolutionary history. The tips of a phylogenetic tree represent the observed entities, which can be living taxa or fossils. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the taxa represented on the tree. An unrooted tree diagram (a network) makes no assumption about directionality of character state transformation, and does not show the origin or "root" of the taxa in question. In addition to their use for inferring phylogenetic pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astyanax Argyrimarginatus
''Astyanax argyrimarginatus'' is a small species of freshwater fish native to various river basins in Brazil. Originally thought to be restricted to the Tocantins-Araguaia river system, a study in 2012 expanded its range to include the Rio Xingu, as well. Specific biotope preferences are unknown, but it is mostly collected from clearwater streams in fairly good health. Its relative abundance and presence in some protected locales means that it is not endangered. This species is a part of a complex centered around congener ''Astyanax bimaculatus''. Visually, it bears similarities to other species also within the complex, including reddish fins and a dark humeral spot, but its most distinguishing feature is a black lateral stripe with bright-silver edges. This stripe is the origin of its scientific name, which means "silver border". Taxonomy ''Astyanax argyrimarginatus'' was originally described in 1999 by Brazilian ichthyologist Valdener Garutti. Given morphological similaritie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astyanax Abramis FishBase
In Greek mythology, Astyanax (; ''Astyánax'', "lord of the city") was the son of Hector, the crown prince of Troy, and of his wife, Princess Andromache of Cilician Thebe."Astyanax". ''Oxford Classical Dictionary''. Oxford, 1949, p. 101 (''s.v.'' "Ἀνδρομάχη"). His birth name was Scamandrius (in Greek: Σκαμάνδριος Skamandrios, after the river Scamander''A Classical Manual: Being a Mythological, Historical, and Geographical Commentary on Pope's Homer and Dryden's Aeneid of Virgil''. J. Murray, 1833, p. 189.), but the people of Troy nicknamed him Astyanax (i.e. high king, or overlord of the city), because he was the son of the city's great defender (''Iliad'' VI, 403) and the heir apparent's firstborn son. During the Trojan War, Andromache hid the child in Hector's tomb, but the child was discovered. His fate was debated by the Greeks, for if he were allowed to live, it was feared he would avenge his father and rebuild Troy. In the version given by the ''Littl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
