Porcupinefish is a family of fishes of the order of Needlefish (Tetraodontiformes). The body is short, covered with elongated and movable spines. Can inflate into a ball, with spines raised and sticking out in all directions, in the usual state adjacent to the body. Includes 7 genera and 19 species. The best known is the hedgehog fish (Diodon hystrix), lo 90 cm long, living in tropical and subtropical waters of the coastal zone. Poor swimmers. Feed on a variety of invertebrates. Of local commercial importance.
In these fish, the fused teeth in each jaw form continuous cutting plates, not separated in front. Their shortened body, covered with spines, is able to inflate in the form of a ball, and in some species, while the dorsal and anal fins are pulled under the skin. Spines covering the body, short and immobile, but in the genera Diodon and Atopomycterus, they are strongly elongated and mobile at the base: when the air sacs folded adjacent to the body, and when inflated fish stand stick out, giving it such a peculiar appearance. Spines of the fish-eater intended for defense, do not have poisonous glands.