[1] 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.

[3] Corydoras are small fish, ranging from 2.5 to 12 cm (1.0 to 4.7 in) in SL.,[2] and are protected from predators by their body armor and by their sharp, typically venomous spines.

These species are given 'C-numbers', originally devised by Hans-Georg Evers for the German fishkeeping magazine DATZ in 1993.

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.

[10] 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.

[13] Corydoras are generally found in smaller-sized streams, along the margins of larger rivers, in marshes, and in ponds.

[2] They are native to slow-moving and almost still (but seldom stagnant) streams and small rivers of South America, where the water is shallow and very murky.

The frequency of this air breathing behavior increases when Corydoras are exposed to water with low oxygen availability, allowing them to tolerate periods of aquatic hypoxia.

Their feeding method is to search the bottom with their sensory barbels and suck up food items with their mouth, often burying their snout up to their eyes.

[15] In several species of Corydoras, it has been observed that the fishes, after initial evasive reaction to threat, lie still; this is suggested to be a form of cryptic behavior.

However, it is also argued that most species do not have cryptic coloration nor freezing behavior and continue to exist,[2] likely due to their armor and venom.

The female will attach her mouth to the male's genital opening, creating the well-known "T-position" many Corydoras exhibit during courtship.

The sperm rapidly moves through her intestines and is discharged together with her eggs into a pouch formed by her pelvic fins.

Corydoras are mostly bottom feeders, so they should be offered sinking pellets as well as supplements of live and frozen foods.