Ichthyologists James Albert and William Crampton have described a new species of apteronotid knifefish from the western Amazon of Peru and Brazil in the latest issue of the journal Systematics and Biodiversity.
The authors name the new species Samuel's ghost knifefish (Compsaraia samueli) after Samuel Albert, who presented them with the type specimens.
Samuel's ghost knifefish is distinguished from the only other species in the genus, C. compsa, in having more caudal-fin rays, a shorter caudal peduncle, a less tapering body shape in lateral profile, and a smaller maximum adult body size.
Video by PFK forum member Amiidae.
Samuel's ghost knifefish has been collected from flooded beaches and deep river channels, with mature males exhibiting extreme elongation and slenderness of the snout and jaws.
The authors observe that the males use their snout and jaws in sparring with repeated aggressive non-contact postures, usually escalating to biting and jaw-locking within minutes.
For more information, see the paper: Albert, JS and WGR Crampton (2009) A new species of electric knifefish, genus Compsaraia (Gymnotiformes: Apteronotidae) from the Amazon River, with extreme sexual dimorphism in snout and jaw length. Systematics and Biodiversity 7, pp. 81"92.