Porcupine fish, which number about fifteen species, resemble puffers. They occur throughout the world in shallow, tropical seas. The family of porcupine fish is distinguished by its crushing upper and lower jaws. A bristling ball of spines is produced when the porcupine inflates itself by swallowing water or air. The larvae of all species go through oddly shaped forms in their development. Porcupine fish are usually cream, yellow, or greenish with striking black and brown stripes and spots. Each species possesses a distinct pattern.