Aspredinids are found throughout the major tropical rivers of South America (e.g., Magdalena, Orinoco, Amazon, São Francisco, Paraguay-Paraná, and Uruguay).

[4] Sexual dimorphism is exhibited in most species in that mature females are typically larger than males; this is, however, reversed in Hoplomyzon sexpapilostoma.

[4] Aspredinids live in a variety of habitats ranging from shallow backwaters to deep river channels to tidal estuaries.

[4] A peculiarity of the catfishes in the subfamily Aspredininae is that after the female's eggs are fertilised by the male, she attaches them to her belly and carries them to shallow water to hatch.

[11] Accounts of reproduction in Bunocephalus vary; some sources state that they are egg-scatterers without any parental care, while others note them to build a depression for a nest and guard the eggs.

Their requirements are similar to those of other tropical South American fish, preferring slightly acidic, not too hard water maintained at 20–25 °C (68–77 °F).