Diodon

Porcupinefishes or balloonfishes are any of the various species of the genus Diodon, the type genus of Diodontidae.

==Distinguishing features== Fish of the genus Diodon have: two-rooted, movable spines (which are derived from modified scales) distributed over their bodies. beak-like jaws, used to crush their hard-shelled prey (crustaceans and molluscs). They differ from the swelltoads and burrfishes (genera Cyclichthys and Chilomycterus, respectively), which, in contrast, have fixed, rigid spines.