Rhabdolichops is a genus of weakly electric glass knifefish (family Sternopygidae, order Gymnotiformes) found in the main channels and larger tributaries of Amazon-basin and neighboring river systems - the atlas's 10 species draw on Brazil, Venezuela, Colombia, Peru, Ecuador, and French Guiana. It shows the classic gymnotiform body plan: elongated and laterally compressed, tapering to a whip-like point without a caudal fin, propelled by undulating a long anal fin rather than flexing the body, which lets it hold position or reverse direction with equal ease in open water. Rhabdolichops runs larger than most of its knifefish relatives, with atlas species reaching 5.5–19.5 in.
Outside a handful of trade staples like the black ghost knife and generic glass knifefish, most gymnotiforms have little presence in the aquarium hobby, and Rhabdolichops is no exception - it is known chiefly through ichthyological river surveys and studies of electric-organ-discharge diversity in open-channel electric fish. The conservation picture is comparatively reassuring, with 8 of the 10 atlas species rated Least Concern, consistent with a genus of wide-ranging, big-river specialists rather than narrow-endemic pool or headwater fish.