This family includes the candiru fish (Vandellia cirrhosa), feared by some people for its alleged habit of entering into the urethra of humans.

[7] Subfamilies and genera include:[1] Trichomycteridae has the greatest distribution of any catfish family.

Miniaturization occurs in many of the trichomycterid subfamilies, including Trichomycterinae, Glanapteryginae, Vandelliinae (in Paravandellia), Tridentinae, and Sarcoglanidinae.

[9] Only the two subfamilies Vandelliinae and Stegophilinae and Tridensimilis of Tridentinae are considered to be parasitic fishes, including the infamous candirú or vampire catfish, feared by some people for its habit of entering into the urethra of humans.

[10] Apart from the free-living, generalized predators of small invertebrates, trophic modes represented by trichomycterids include the hematophagy (feeding on blood) in Vandelliinae, the lepidophagy (scales) and mucophagy (mucus) in some Stegophilinae and necrophagy (carrion) in others, and partial algivory (algae) in Copiondontinae.

Such species include Ituglanis bambui, I. epikarsticus, I. passensis, I. ramiroi, and Silvinichthys bortayro.