Callichthys Dianema Hoplosternum Lepthoplosternum Megalechis Aspidoras Corydoras (including Brochis) Gastrodermus Hoplisoma Osteogaster Scleromystax Callichthyidae is a family of catfishes (order Siluriformes), called armored catfishes due to the two rows of bony plates (or scutes) along the lengths of their bodies.

[2] Callichthyidae is one of six families in the superfamily Loricarioidea, and is sister to a clade formed by Scoloplacidae, Astroblepidae, and Loricariidae.

[8] In a 2004 study, different relationships among the callichthyines were found: Dianema and Hoplosternum form the most basal clade, and Callichthys is sister to Lepthoplosternum and Megalechis.

[5] It also suggests an earlier differentiation of loricarioids in comparison to other catfishes, or a lack of older fossils of other Neotropical groups.

[12] The Neotropical family Callichthyidae is found in most South American river drainages (Paraná-Paraguay, São Francisco, Atlantic Coastal basins in Brazil, Amazon, Orinoco, Maracaibo, Magdalena).

Callichthyidae present the highest species richness in the headwaters of the Amazonas drainage and those rivers draining the Guiana Shield.

[3] The subfamily Corydoradinae is found east of the Andes and north of the Rio de La Plata system.

The upper row of lateral scutes may either meet on the back or a narrow bare area may be filled with small oval or roundish bony platelets.

Species of the Corydoradinae are of small size (maximum about 9 cm (3.5 in) in standard length) and are easily distinguished from other callichthyids by their deep bodies and short maxillary barbels.

Callichthyids inhabit a wide range of habitats, from small, swift, oxygen-rich creeks to big rivers and flooded areas.

[3] Some callichthyids are able to absorb air through their hind guts to move short distances on land.