Knifefish

Knifefish may refer to several knife-shaped fishes:

• The Neotropical or weakly electric knifefishes, order Gymnotiformes, containing five families:
  • Family Gymnotidae (banded knifefishes and the electric eel)
  • Family Rhamphichthyidae (sand knifefishes)
  • Family Hypopomidae (bluntnose knifefishes)
  • Family Sternopygidae (glass and rat-tail knifefishes)
  • Family Apteronotidae (ghost knifefishes)
• The featherbacks, family Notopteridae.
• The aba, Gymnarchus niloticus
• Four other unrelated fish species not in any of the above families:
  • Grey knifefish, Bathystethus cultratus.
  • Blue knifefish, Labracoglossa nitida.
  • Collared knifefish or finscale razorfish, Cymolutes torquatus.
  • Jack-knifefish, Equetus lanceolatus.