HomeFreshwater aquarium fishCatfish & plecosRock-bacu Rock-bacu (Lithodoras dorsalis) Scientific name: Lithodoras dorsalis Valenciennes, 1840 The Rock-bacu (Lithodoras dorsalis) is a freshwater fish of the family Doradidae. Native range: South America, Amazon River basin and estuary near Cayenne, French Guiana. BiologyDorsal spines (total): 1; Dorsal soft rays (total): 6; Anal soft rays: 13 - 14. Body elongated, without scales, almost covered with bony plaque, ventrally flattened in adults. Terminal mouth has three pairs of barbels. Lower jaw is shorter than the upper jaw. Eyes small.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameLithodoras dorsalisFamilyDoradidae (Thorny catfishes)OrderSiluriformes (Catfish)ClassActinopterygii (Ray-finned fishes)Maximum length100.0EnvironmentFreshwater; demersal; potamodromousClimateTropicalDistributionSouth America: Amazon River basin and estuary near Cayenne, French Guiana.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessUsesFisheries: minor commercial; aquarium: commercialResilienceLow, minimum population doubling time 4.5 - 14 years (Preliminary K or Fecundity.) More catfish & plecosAmazon sailfin catfishPterygoplichthys pardalisMystus tengaraChannel catfishIctalurus punctatusPhilippine catfishClarias batrachusSuckermouth catfishHypostomus plecostomusGhost CatfishKryptopterus minorSee all catfish & plecos SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026