The ripsaw catfish (Oxydoras niger) or cuiu cuiu is a species of thorny catfish native to the tropical river basins of South America being found in Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru and Venezuela. This species grows to a length of 100.0 centimetres (39.4 in) SL and weights up to 13 kilograms (29 lb). This species is a minor component of local commercial fisheries. Has lateral thorns that can damage a potential predator or handler. It feeds by...