Río Biobío
Diplomystids are generalized carnivores that consume annelids, mollusks, and arthropods. Specimens of "D. nahuelbutaensis" from fast-flowing, moderate-elevation (370–520 m) tributaries of the Bío Bío River had eaten aquatic insect larvae, especially chironomids, and the relatively large decapod crustacean "Aegla".