The shipworm, also known as the ship chiseling shell. Mollusks. Shaped like a worm, elongated body, burrowing in wood. There are two small symmetrical white shells at the front of the body, and a very thin white calcareous tube encasing the rest of the body. At the end of the body there is an entry pipe and a drain. At the base of the water pipe there is an armor shaped like a small shovel, in case of enemies, the water pipe retracted, with the armor to block the hole. Widely spread in the world's oceans, the marine docks, wooden piles and wooden boats and other wooden equipment to destroy serious.