Xenotoca is a genus of fish in the family Goodeidae from Mexico, where found in a wide range of habitats, from rivers and creeks to pools and lakes, in the LermaGrande de Santiago, Panuco, Cuitzeo and other basins of the Mesa Central. While no goodeid is a very common aquarium fish, the redtail splitfin (X. eiseni), is one of the most common aquarium goodeids. Its relatively bright colors offset its reputation for being aggressive towards tankmates, occasionally even killing them.[2] Similarly to that species, two species described in 2016 have males with red-orange tails, but this feature is not shared by the remaining members of the genus.[3] The Xenotoca species are small, reaching up to 9 cm (4 in) in standard length.[4]

Xenotoca
Xenotoca eiseni
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cyprinodontiformes
Family: Goodeidae
Subfamily: Goodeinae
Genus: Xenotoca
C. L. Hubbs & C. L. Turner, 1939
Type species
Characodon variatus
Bean, 1887[1]

Species edit

X. doadrioi was only scientifically described in 2016 (it was formerly considerec a variant of X. eiseni). Like the other "redtails", only the male has a red-orange tail

There are currently five recognized species in this genus,[3][5] but two possibly undescribed species, tentatively referred to as Xenotoca cf. melanosoma and Xenotoca cf. variata, are known.[6][7]

Genetic work has shown that the genus, as currently defined, is not monophyletic: The type species X. variata is distantly related to the remaining, which eventually will be reallocated to their own genus.[3] Phylogenic research by Shane Webb showed that the closest relative of X. variata is the butterfly goodeid, Ameca splendens.[8]

References edit

  1. ^ Eschmeyer, William N.; Fricke, Ron & van der Laan, Richard (eds.). "Xenotoca". Catalog of Fishes. California Academy of Sciences. Retrieved 22 September 2019.
  2. ^ "Xenotoca eiseni". SeriouslyFish. Retrieved 16 February 2016.
  3. ^ a b c Domínguez-Domínguez, O.; Bernal-Zuñiga, D.M.; Piller, K.R. (2016). "Two new species of the genus Xenotoca Hubbs and Turner, 1939 (Teleostei, Goodeidae) from central-western Mexico". Zootaxa. 4189 (1): 81–98. doi:10.11646/zootaxa.4189.1.3. PMID 27988757.
  4. ^ "Xenotoca variata". Goodeid Working Group. Retrieved 24 September 2018.
  5. ^ Froese, Rainer and Pauly, Daniel, eds. (2012). Species of Xenotoca in FishBase. August 2012 version.
  6. ^ ""Xenotoca" cf. melanosoma". Goodeid Working Group. Retrieved 24 September 2018.
  7. ^ ""Xenotoca" cf. variata". Goodeid Working Group. Retrieved 24 September 2018.
  8. ^ Webb, Shane A.; Graves, Jefferson A.; Macias-Garcia, Constantino; Magurran, Anne E.; Foighill, Diarmaid O.; Ritchie, Michael G. (March 2004). "Molecular phylogeny of the livebearing Goodeidae (Cyprinodontiformes)". Molecular Phylogenetics and Evolution. 30 (3): 527–544. doi:10.1016/S1055-7903(03)00257-4. PMID 15012937. Retrieved 2023-06-01.