Scientists in Colombia and the USA have described a new species of ghost knifefish.
The new species, named Apteronotus galvisi, after the prominent Colombian ichthyologist German Galvis, is described from the Ro Meta drainage in Colombia by Carlos de Santana, Javier Maldonado-Ocampo and William Crampton in a paper published in the latest issue of the journal Ichthyological Exploration of Freshwaters.
Apteronotus galvisi can be distinguished from other members of the genus in having the following combination of characters: hypermorphosis of the sphenoid region of the neurocranium in both males and females, ossified lateral ethmoid, uniformly brown body coloration except for white or yellow band on the chin and mid-dorsal surfaces of the head and body, and an unpigmented band encircling the base of the caudal fin.
Males of A. galvisi differ from males of A. macrostomus in having a shorter, narrower and more slender head, and a shorter snout.
When compared to males of A. leptorhychus, males of A. galvisi have a shorter anal-fin base and a shorter, narrower and more slender head. The new species was collected from typical piedmont rivers with clear waters, a rocky bottom and a strong current.
There are 17 valid species of Apteronotus recognized, with the new species and four other species (A. leptorhynchus, A. rostratus, A. spurrellii and A. macrostomus) thought to belong to a monophyletic group diagnosed within the Apteronotidae by the following: hypermorphosis of the sphenoid region of the neurocranium in both males and females, uniformly brown body coloration except for white or yellow band on the chin and mid-dorsal surfaces of the head and body, an unpigmented band encircling the base of the caudal fin, and the mouth extending posteriorly beyond the vertical through the posterior margin of the eye.
For more information, see the paper: de Santana, CD, JA Maldonado-Ocampo and WGR Crampton (2007) Apteronotus galvisi, a new species of electric ghost knifefish from the Ro Meta basin, Colombia (Gymnotiformes: Apteronotidae). Ichthyological Exploration of Freshwaters 18, 117"124.