Predatory fishes prey most often on weak members of an animal population. They select weak, ill, injured, or dying prey because it is easier to catch. They strain plankton from the water with gill rakers. Some bony fishes are quite specialized for feeding. When an unsuspecting animal swims by, the stonefish swiftly gulps it.
Some fishes produce strong electric current to stun prey.
A species'particular mouth shape and teeth are adapted to accommodate a particular diet. These fish are herbivores that eat the algae within the coral. In the process, they grind the coral's hard exoskeleton and defecate sand. D. Fish as biological control agents. Bony fishes have been used to control undesirable organisms.