How do archer fishes use their mouths differently from most other perciform fishes?

While many perciform fishes possess specialized jaw structures for capturing prey—such as protrusible mouths for suction feeding or specialized teeth for piercing or crushing—the archer fish (family Toxotidae) utilizes a unique anatomical modification to hunt.12

Unlike most other perciforms, the archer fish has a mouth modified to form a groove along the roof of its palate. By pressing its tongue against this groove, the fish creates a tube that allows it to "shoot" or eject drops of water with high accuracy. This behavior enables the fish to knock insect prey off overhanging vegetation, causing the insects to fall into the water where they can be consumed. While some other species, such as the butterfly fish, exhibit similar but less powerful squirting behavior, this mechanism is a distinct departure from the typical predatory strategies—such as ambush, pursuit, or suction feeding—employed by the broader order of perciform fishes.231