Puffers have loose skin lacking scales and pelvic fins and knife-edged jaws composed of left and right plates above and below.  They feed upon a variety of invertebrates and inflate themselves with water to become more difficult for predators to swallow or wedge themselves into a crevice.  Spines are reduced to tiny prickles but all parts of the fish contain deadly tetrodotoxin.  Primary locomotion is produced by sculling the dorsal, anal, and pectoral fins, reserving the tail for sudden bursts.  Porcupinefishes have stout spines or burrs and each jaw consists of a single cutting edge.

Mouth showing four teeth