Astyanax jordani

{{Short description|Species of fish}}

{{Speciesbox

| image = Astyanax jordani Tétra aveugle Aquarium Liège 30012016 01.jpg

| image_caption =

| status = EN

| status_system = IUCN3.1

| status_ref = {{cite iucn|author = Ornelas García, P. |year=2019 |title= Astyanax jordani |page= e.T191201A1972594 |doi=10.2305/IUCN.UK.2019-3.RLTS.T191201A1972594.en |access-date=6 May 2024}}

| taxon = Astyanax jordani

| authority = (C. L. Hubbs & Innes, 1936)Hubbs, C. L. and W. T. Innes. 1936. "The first known blind fish of the family Characidae: a new genus from Mexico"; Occ. Pap. Mus. Zoo. 342: 1-7. University of Michigan.

| synonyms_ref =

| synonyms = Anoptichthys jordani

Anoptichthys antrobius

}}

Astyanax jordani is a freshwater fish of the characin family (family Characidae) of

order Characiformes, native to Mexico.{{FishBase|genus=Astyanax|species=jordani|year=2015|month=October}}{{ITIS |id=639371 |taxon=Astyanax jordani |accessdate=1 July 2006}} It is sometimes called the cave tetra, or by its local Spanish name sardina ciega.

A blind cave fish, A. jordani is very closely related to the Mexican tetra (A. mexicanus) and their taxonomy is disputed. Some treat the two as variants of a single species (in which case A. jordani is a junior synonym of A. mexicanus) and this is supported by phylogenetic evidence,Jeffery, W. (2009). Regressive evolution in Astyanax cavefish. Annu. Rev. Genet. 43, 25–47.Bradic, M., Beerli, P., Garcia-de Leon, F. J., Esquivel-Bobadilla, S. & Borowsky, R. L. (2012). Gene flow and population structure in the Mexican blind cavefish complex (Astyanax mexicanus). BMC. Evol. Biol. 12, 9.Dowling, T. E., Martasian, D. P. & Jeffery, W. R. (2002). Evidence for multiple genetic forms with similar eyeless phenotypes in the blind cavefish, Astyanax mexicanus. Mol. Biol. Evol. 19, 446–455.Strecker, U., Faúndez, V. H. & Wilkens, H. (2004). Phylogeography of surface and cave Astyanax (Teleostei) from Central and North America based on cytochrome b sequence data. Mol. Phylogenet. Evol. 33, 469–481.{{cite book | author=Keene | author2=Yoshizawa | author3=McGaugh | name-list-style=amp | title=Biology and Evolution of the Mexican Cavefish | year=2016 | pages=77–87 | publisher=Elsevier Science | isbn=978-0-12-802148-4}} but others continue to recognize the two as separate species.{{FishBase_genus | genus=Astyanax | year=2017 | month=April}}

A. jordani is listed on the IUCN Red List as Endangered on the basis of a dwindling population and an acutely-restricted, highly variable habitat. It is fairly resilient, however, having a population doubling time of 15 months.

The fish was named in honor of C. Basil Jordan of the Texas Aquaria Fish Company (Dallas, Texas), who donated the first type specimens and documented and observed the first wild blind characins known to science.{{cite web | url = https://etyfish.org/stethaprioninae/ | title = Family CHARACIDAE: Subfamily STETHAPRIONINAE Eigenmann 1907 (American Tetras) | access-date= 6 May 2024 | author1 = Christopher Scharpf | author2 = Kenneth J. Lazara | name-list-style = amp | work = The ETYFish Project Fish Name Etymology Database | publisher = Christopher Scharpf and Kenneth J. Lazara | date = 15 April 2024}}

It reportedly has been introduced to the Philippines.