A porcupine amidst fish

• A porcupine amidst fish (porcupine fish (Diodon hystrix))

The spiny puffer, or burr fish, has a unique defensive mechanism that protects it from predators. They mostly live in tropical seas, but a few occur in fresh or brackish waters.  Puffers are usually about 45 cm (about 18 in) long, although some species are larger. When threatened, the spiny puffer inflates its body with water or air, which causes the numerous long spines covering the body to be erected. The inflated body and the sharp spines make it difficult for a predator to ingest the puffer. After the danger has passed, the puffer slowly deflates itself and resumes a more normal shape. Also called blowfish and globefish, they are named for their habit of inflating themselves with water or air when threatened.Then it appears like Durion fruit. Puffers are used as food fishes, but some species are very poisonous unless prepared properly.