Gastrodermus is one of the genus-level lineages split out from the traditional, broadly defined Corydoras in the 2024 taxonomic revision of the group (family Callichthyidae). Judging by the species placed here in the atlas - the dwarf corydoras (hastatus), pygmy cory (pygmaeus), little corydoras (nanus), elegant cory (elegans), and shy cory (gracilis) among them - this lineage corresponds to what hobbyists have long informally called the dwarf or 'elegans-group' corydoras. The atlas covers 15 species at 1–2 in, among the smallest armored catfish in the family, native to Amazon and adjacent river systems across Brazil, Bolivia, Argentina, Colombia, Ecuador, Paraguay, Peru, and French Guiana. Because the split is recent, most species in this grouping are still catalogued individually under the older name Corydoras, alongside a few already updated, such as Gastrodermus nijsseni and G. pauciradiatus.
This lineage includes some of the most popular dwarf catfish in the freshwater hobby: the pygmy cory, dwarf corydoras, and elegant cory are nano- and planted-tank staples, valued for their small adult size, peaceful shoaling behavior, and tolerance of a wide range of water conditions - a contrast to some of the larger, more specialized corydoras elsewhere in the atlas. Conservation status leans favorable where assessed, with 8 of the 15 species Least Concern, though 4 Data Deficient and 3 Not Evaluated listings show that even well-loved aquarium species in this group still carry real gaps in formal wild-population assessment.