Mastiglanis asopos is a species of three-barbeled catfish.

It spends the daytime buried in the top layer of sand.

As an ambush predator, when foraging, it poises in the streamlet channel where water is flowing, supported by a tripod formed by its pelvic and anal fins, spreading both its very long barbels and the filamentous dorsal and pectoral-fin rays, thus forming a kind of "drift-trap".

When the fish intercepts food, it will lunge at these food particles; after lunging for a short distance, it will return to its previous hunting spot.

[1] Small trichopteran larvae (ingested with the sand cases) and ephemeropterans constituted a considerable portion of the gut contents in a study of Mastiglanis asopos, but their foraging behavior allows a varied diet which includes large chironomid larvae and small adult beetles that would not be consumed by other sand-dwelling animals.