OxydorasOxydoras is a genus of thorny catfishes native to tropical South America.SpeciesThere are currently three recognized species in this genus:Oxydoras kneri Bleeker, 1862Oxydoras niger Oxydoras sifontesi Fernández-Yépez, 1968DescriptionOxydoras species are relatively large, reaching between 70-100 centimetres in length. O. kneri has a maximum published weight of. O. niger gets even heavier, with a maximum published weight of.