 Trumpetfish is a largely piscivorous ambush predator which is known to hide among shoals of large herbivorous fish, shadowing the fish until it is close enough to a prey item to strike.It will also hang vertically among gorgonians or drift with the current, capturing any prey that swim underneath it by sucking them into the mouth which has elastic tissues to allow it to open as wide as the diameter of its body.The sudden opening of the mouth creates a vacuum which pulls prey into the mouth.