Sub-surface flies are designed to resemble a wide variety of prey including aquatic insect larvae, nymphs and pupae, baitfish, crayfish, leeches, worms, etc.

They feed on aquatic insect larvae and on terrestrial insects they catch on the water surface.

As aquatic insect larvae hatch in the course of the summer, fish become more prominent in the diet.

The juveniles feed mostly on shrimps and aquatic insect larvae; larger individuals about 17 cm long also take small cichlids, minnows, and labeos.

The adult diet consists of aquatic insect larvae (mayflies, caddisflies, dragonflies), but can also include crayfish, leeches, snails, and other small fish.