The world of the crustaceans is a world of bizarre shapes and adaptations. This group of animals is probably best-known for their hard outer shell. As the animal grows, this shell must be removed and discarded. Once this takes place, the new shell takes time to harden. During this period, the animal is without its primary means of protection and vulnerable to attack from predators. But they have an impressive arsenal of weapons at their disposal. The claw of many crustaceans is capable of exerting hundreds of pounds of pressure. Some even have the unique ability to produce a deafening miniature sonic boom with which they stun their prey. The mantis shrimp can even break the glass of an aquarium or split a man's thumb to the bone with one strike. But in spite of their impressive armor and fierce weaponry, the crustaceans do occasionally meet their match. The teeth of the triggerfish and the beak of the octopus can crack through the toughest shells of crabs and lobsters, making an enjoyable meal. Below is a listing of some of the more common crustaceans to be found on the reef.