Astyanax (fish)

Template:Short description Template:Automatic taxobox

Astyanax is a genus of freshwater ray-finned fishes belonging to the family Acestrorhamphidae, the American characins.<ref name="Cof family">Template:Cof family</ref> 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,<ref name="FB">{{#invoke:Cite taxon|main|fishbase|genus=|species=|subspecies=}}</ref> 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 taxonomic position is disputed: Some recognize it as part of the Mexican tetra (A. mexicanus) and this is supported by phylogenetic evidence,<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref><ref>Template:Cite journal</ref><ref>Template:Cite journal</ref><ref name="Keene2016">Template:Cite book</ref> but others recognize the cave form as a separate species, A. jordani.<ref name=FB/>

The type species is A. argentatus,<ref name = "Cof family"/> which was formerly regarded as a synonym of A. mexicanus.<ref name = "Cof genus"/> The generic name comes from Astyanax, a character in Greek mythology, who was the son of Hector of Troy; a reference to the large silver scales of the type species, resembling armor.<ref name = ETYFish>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Taxonomy and systematics

This genus is more or less defined as in 1917 by Carl H. Eigenmann. The lack of comprehensive phylogenetic analyses dealing with this genus is hindering a thorough review and the relationships remain as indeterminate as the monophyly is doubtful. The results of 2020 study using a combination of molecular and morphological data appeared to confirm that Astyanax is not monophyletic and suggested the creation of two new genera and the resurrection of Psalidodon.<ref>Template:Cite journal</ref>