Rhamphichthyidae Explained

Sand knifefish are freshwater electric fish of the family Rhamphichthyidae, from freshwater habitats in South America.

Just like most part of the members of the Gymnotiformes group, they also have elongated and compressed bodies and electric organs. The long anal fin actually extends from before the pectoral fins to the tip of the tail. There is no dorsal fin. Teeth are absent in the oral jaws and the snout is very long and tubular. The nostrils are very close together. This group is sometimes known as the tubesnout knifefishes for this reason.^[1]

They are nocturnal and burrow in the sand during the day.

Genera

According to FishBase there are only three genera in this family, but a comprehensive molecular study from 2015 showed that two additional genera belong here (formerly in Hypopomidae, marked with stars* in list),^[2] and this has been followed by recent authorities.^{[3] [4] [5]}

• Gymnorhamphichthys
• Hypopygus
  • Iracema
• Rhamphichthys
• Steatogenys

See also

• List of fish families

Notes and References

1. Book: Nelson, Joseph, S. . Fishes of the World . John Wiley & Sons, Inc. . 2006 . 0-471-25031-7.
2. Tagliacollo, V.A. . Bernt, M.J. . Craig, J.M. . Oliviera, C. . Albert, J.S. . 2015 . Model-based Total Evidence phylogeny of Neotropical electric knifefishes (Teleostei, Gymnotiformes) . Mol Phylogenet Evol . 95 . 20–33 . 10.1016/j.ympev.2015.11.007 . 26616344 . free . 11449/168204 . free .
3. Ferraris Jr, C.J. . C.D. de Santana . R.P. Vari . 2017 . Checklist of Gymnotiformes (Osteichthyes: Ostariophysi) and catalogue of primary types . Neotrop. Ichthyol. . 15 . 1 . 10.1590/1982-0224-20160067 . free .
4. Book: van der Sleen, P. . J.S. Albert . 2017 . Field Guide to the Fishes of the Amazon, Orinoco, and Guianas . Princeton University Press . 337–341 . 978-0691170749 .
5. Web site: Eschmeyer, W.N. . R. Fricke . R. van der Laan . 12 May 2018 . Catalog of Fishes . California Academy of Sciences . 12 May 2018 .