Notopteridae

Featherbacks
Chitala chitala
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Osteoglossiformes
Family:	Notopteridae
Genera
Chitala Notopterus Papyrocranus Xenomystus

The family Notopteridae contains eight species of osteoglossiform (bony-tongued) fishes, commonly known as featherbacks and knifefishes. They are small fishes living in freshwater or brackish environments in Africa and South-east Asia.

With the denotation of "knifefish", the Notopterids should not be confused with Gymnotiforms, the electric knifefishes. Although their manner of swimming is similar, the two groups are not closely related.

A few of the larger species, especially Chitala chitala, are food fish and occasionally aquarium pets. The name is from Greek noton meaning "back" and pteron meaning "fin".

Description

Featherbacks have slender, elongated, bodies, giving them a knife-like appearance. The caudal fin is small and fused with the anal fin, which runs most of the length of the body. Where present, the dorsal fin is small and narrow, giving rise to the common name of "featherback". The fish swims by holding its body rigid and rippling the anal fin to propel itself forward or backwards.^[1]

Notopterids have specialized swim bladders. The organ extends throughout the body and even into the fins in some cases. Although the swim bladder is not highly vascularised, it can absorb oxygen from air and also functions to produce sound by squeezing air through a narrow passage into the pharynx.^[1]

At least some species prepare nests and guard the eggs until they hatch.^[1]

Species

There are ten species in four genera:^[2]

Family Notopteridae

• Genus Chitala
  • Indochina featherback, Chitala blanci (d'Aubenton, 1965).
  • Chitala borneensis
  • Clown knifefish, Chitala chitala (Hamilton, 1822).
  • Chitala hypselonotus
  • Giant featherback, Chitala lopis (Bleeker, 1851).
  • Clown featherback, Chitala ornata (Gray, 1831).
• Genus Notopterus
  • Bronze featherback, Notopterus notopterus (Pallas, 1769).
• Genus Papyrocranus
  • Reticulate knifefish, Papyrocranus afer (Günther, 1868).
  • Papyrocranus congoensis (Nichols & La Monte, 1932).
• Genus Xenomystus
  • African knifefish, Xenomystus nigri (Günther, 1868).

References

• Berra, Tim M. (2001). Freshwater Fish Distribution. San Diego: Academic Press. ISBN 0-12-093156-7
• "Notopteridae". FishBase. Ed. Rainer Froese and Daniel Pauly. January 2006 version. N.p.: FishBase, 2006.
• The historical biogeography of the freshwater knifefishes.