Comprehensive DescriptionRead full entry
Rosen’s Tube Snout Electric Knifefish (Sternarchorhynchus roseni) lives primarily in the deep waters of the main channels of rivers in the Orinoco River system of northern South America. It is a member of the Electric Knifefish family Apteronotidae, which is part of the order Gymnotiformes. The most famous member of this order is the Electric Eel (Electrophorus electricus), which can (as indicated by its name) generate a strong electrical discharge, delivering a potent shock that can stun prey. Although no other member of the order can deliver such shocks, all of them, including Rosen’s Tube Snout Electric Knifefish, generate and receive weak electrical signals. These function in communication using electrical signals (electrocommunication), facilitate information exchange between potential mates, and provide a way to detect other organisms and items in surrounding waters (electroreception). Rosen’s Tube Snout Electric Knifefish uses its electrical sensory system to locate small prey items, usually insects, hiding in mud and in the debris at the bottom of major rivers. It then uses the pincer-like jaws at the end of its long snout to pull the prey from its hiding place and suck it into the mouth.
During certain times of the year, the males of this species produce very well developed teeth at the end of the lower jaw. These teeth are presumably used in confrontations during breeding contests.
de Santana and Vari (2010) provide a technical morphological description and diagnosis.