Callichthys callichthys

Callichthys callichthys, the cascarudo, armored catfish, bubblenest catfish, hassar, or mailed catfish, is a subtropical freshwater fish belonging to the subfamily Callichthyinae of the family Callichthyidae. It was originally described as Silurus callichthys by Linnaeus in 1758. It is likely to represent a species complex. C. callichthys is distributed in all major river drainages of South America. It is very wide-ranging, extending from Trinidad to Buenos Aires, Argentina, including the upper Amazon River and Paraguay River systems.