Xyliphius is a genus of banjo catfish in the family Aspredinidae, found across major South American river systems from Venezuela and Colombia south through Ecuador, Peru, and Brazil, into Argentina. The atlas covers 7 species, mostly small — from about 1.5 in up to under 6 in — with the flattened head and slender, tapering tail that give banjo catfish their name and their characteristic silhouette. Like their aspredinid relatives, they are bottom-dwelling fish of sandy and silty river channels, often in areas of strong current or turbid water, and several species show reduced eyes or other adaptations associated with life on or under fine substrate.
Common names in the atlas — the Bearded banjo catfish (Xyliphius barbatus) and the Shark banjo catfish (X. lepturus) — hint at a genus that is more a curiosity for specialist catfish keepers and researchers than a mainstream aquarium fish; most species are rarely if ever collected for the trade. The genus is also poorly studied: two species in the atlas are Data Deficient and two more have not yet been formally assessed, and even the three Least Concern species mostly reflect limited survey coverage of large, silty river channels rather than confirmed abundance.