A. calvus dines on insect larvae, small crustaceans and small fry that they suck out of the crevices in the rocks. They are laterally compressed, the specialization that allows them access to these foods where other cichlids cannot. They thrive on mysis shrimp, krill, salad shrimp, flakes, pellet and brine shrimp in the aquarium. Despite their large mouth size, they should not be a threat to other adult fish in the aquarium, including adult shelldwellers.