Wiktionary
n. Any of a genus (taxlink Corydoras genus noshow=1) of small freshwater tropical catfish often kept in aquariums.
Wikipedia
Corydoras is a genus of freshwater catfish in the family Callichthyidae and subfamily Corydoradinae. The species are 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 found 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.