Corydoras is a genus of freshwater catfish in the family Callichthyidae and subfamily Corydoradinae. The species usually have more restricted areas of endemism than other callichthyids, but the area of distribution of the entire genus almost equals the area of distribution of the family, except for Panama where Corydoras is not present. Corydoras species are distributed in South America where they can be found from the east of the Andes to the Atlantic coast, from Trinidad to the Río de la Plata drainage in northern Argentina. Species assigned to Corydoras display a broad diversity of body shapes and coloration. Corydoras are small fish, ranging from in SL., and are protected from predators by their body armor and by their sharp, typically venomous spines. Taxonomy The name Corydoras is derived from the Greek kory (helmet) and doras (skin). Corydoras is by far the largest genus of Neotropical fishes with more than 160 species. It is the sole genus in the tribe Corydoradini. C. difluviatilis is recognized as the basalmost species of Corydoradini, exhibiting several plesiomorphic features compared to the other species of Corydoras. The type species for this genus is Corydoras geoffroy. Several hundred species are not yet classified, but kept by aquarists. These species are given 'C-numbers', originally devised by Hans-Georg Evers for the German fishkeeping magazine DATZ in 1993. In 2006, 153 C-numbers had been assigned, of which 32 had been assigned appropriate scientific names. The species C. barbatus, C. macropterus and C. prionotos have been reclassified into the genus Scleromystax. Brochis had been differentiated from Corydoras due to the higher number of dorsal fin rays; however, Brochis has recently been suggested to be a synonym of Corydoras. This is contested and has not been universally accepted. The sixray corydoras belongs in Aspidoras. Brochis Brochis is a formerly recognized genus of catfish. Between one and three fish of the Callichthyidae in the Siluriformes order are referred to as Brochis, however following recent classification these three species have been grouped in the genus Corydoras. The genus is considered defunct by most scientific authorities, or as a junior synonym or subgenus of Corydoras. Consequently, it is an example of Obsolete taxa Despite being considered defunct, there are several morphological differences that fish formerly classified in the genus Brochis have. These include a noticeably larger body, a more lyre-like tail and most decisively, the extended dorsal fins that have more rays than