An order of teleost fishes composed of about 257 species, most of which have a small mouth at the end of a long tubular snout and body armor of dermal plates or bony rings. They are further identified by the absence of supramaxillary, orbitosphenoid and basisphenoid bones; and a pelvic girdle that is not connected to the cleithra. Gasterosteiforms are carnivorous predators, feeding chiefly on crustaceans, which they siphon from the water with their tubelike mouthparts. Large species such as trumpetfishes and cornetfishes are primarily piscivorous. Sticklebacks, pipefishes, and seahorses are popular aquarium fishes.