Black Ghost Knifefish

The Black Ghost knifefish, Apteronotus albifrons, is a tropical fish belonging to the ghost knifefish family (Apteronotidae). They originate in South America in the Amazon Basin in Peru and from Venezuela through Paraguay in the Paraná Rivers. They are sometimes found in aquaria. The fish is all black except for two white rings on its tail. It moves mainly by undulating a long fin on its underside. It will grow to a maximum length of 20 in (50 cm).

The Black Ghost knifefish natively lives in fast moving, sandy bottom creeks in a tropical climate. They prefer water with a 6.0 – 8.0 pH, a water hardness of 5.0 – 19.0 dGH, and a temperature range of 73-82 F (23-28 C). They are nocturnal, but they are weakly electric fish and use an electric organ and receptors distributed over the length of their body in order to find insect larvae.

Due to their electrical charge, a close, contained group of knife fish (as in an aquarium) will line up side by side.

Image Credit: Photo by and (c)2005 Derek Ramsey/Wikimedia Commons (CC BY-SA 2.5)