 Several species of wrasse hold bivalves (scallops, clams and urchins) in their mouth and smash them against the surface of a rock (an "anvil") to break them up.This behaviour in an orange-dotted tuskfish ("Choerodon anchorago") has been filmed; the fish fans sand to unearth the bivalve, takes it into its mouth, swims several metres to a rock which it uses as an anvil by smashing the mollusc apart with sideward thrashes of the head.Archerfish (family Toxotidae) squirt jets of water at insects on plants above the surface to knock them into the water; they can adjust the size of the squirts to the size of the insect prey and learn to shoot at moving targets.