Why Can We Hear The Sound Of The Ocean When We Hold A Dry Seashell To Our Ear ?
Seashell A seashell is a protective outer layer usually created by an animal or organism that lives in the sea. They use mollusks to make shells to protect their soft insides. [14] You can see empty seashells washed up on beaches by beachcombers. The shells are empty because the animal has died, and the soft parts have decomposed or eaten by another organism. A seashell is usually the exoskeleton of an invertebrate (an animal without a backbone) and is typically composed of calcium carbonate[14] or chitin. Most shells on beaches are the shells of marine mollusks, made of calcium carbonate, and endure better than shells made of chitin. Apart from mollusk shells, other shells on beaches are those of barnacles, horseshoe crabs, and brachiopods. Marine annelid worms in the family Serpulidae create shells made of calcium carbonate cemented onto other surfaces. The shells of sea urchins are called tests, and the molted shells of crabs and lobsters are exuviae. While most seashells are extern