Main

  • Seashell

    Seashell


    • A seashell or sea shell, also known simply as a shell, is a hard, protective outer layer created by an animal that lives in the sea. The shell is part of the body of the animal. Empty seashells are often found washed up on beaches by beachcombers. The shells are empty because the animal has died and the soft parts have been eaten by another animal or have rotted out.

      The term seashell usually refers to the exoskeleton of an invertebrate (an animal without a backbone). Most shells that are found on beaches are the shells of marine mollusks, partly because many of these shells endure better than other seashells.

      Apart from mollusk shells, other shells that can be found on beaches are those of barnacles, horseshoe crabs and brachiopods. Marine annelid worms in the family Serpulidae create shells which are tubes made of calcium carbonate that are cemented onto other surfaces. The shells of sea urchins are called tests, and the moulted shells of crabs and lobsters are called exuviae. While most seashells are external, some cephalopods have internal shells.

      Seashells have been used by humans for many different purposes throughout history and pre-history. However, seashells are not the only kind of shells; in various habitats, there are shells from freshwater animals such as freshwater mussels and freshwater snails, and shells of land snails.



      Some hermit crab species live on land and may be found quite some distance from the sea, including those in the tropical genus Coenobita.
      • Carrier shells in the family Xenophoridae are marine shelled gastropods, fairly large sea snails. Most species of xenophorids cement a series of objects to the rim of their shells as they grow. These objects are sometimes small pebbles or other hard detritus. Very often shells of bivalves or smaller gastropods are used, depending on what is available on the particular substrate where the snail itself lives. It is not clear whether these shell attachments serve as camouflage, or whether they are intended to help prevent the shell sinking into a soft substrate.
      • Small octopuses sometimes use an empty shell as a sort of cave to hide in, or hold seashells around themselves as a form of protection like a temporary fortress.
      • Almost all genera of hermit crabs use or "wear" empty marine gastropod shells throughout their lifespan, in order to protect their soft abdomens, and in order to have a strong shell to withdraw into if attacked by a predator. Each individual hermit crab is forced to find another gastropod shell on a regular basis, whenever it grows too large for the one it is currently using.
      • The most common species of shells to be used as currency have been Monetaria moneta, the "money cowry", and certain dentalium tusk shells, used in North Western North America for many centuries.
      • Many of the tribes and nations all across the continent of Africa have historically used the cowry as their media of exchange. The cowry circulated, historically, alongside metal coins and goods, and foreign currencies. Being durable and easy to carry the cowry made a very favorable currency.
      • Some tribes of the indigenous peoples of the Americas used shells for wampum and hair pipes. The Native American wampum belts were made of the shell of the quahog clam.
      • Giant clams (Family Tridacnidae) have been used as bowls, and when big enough, even as bathtubs and baptismal fonts.
      • Melo melo, the "bailer volute", is so named because Native Australians used it to bail out their canoes.
      • Many different species of bivalves have been used as scrapers, blades, clasps, and other such tools, due to their shape.
      • Some marine gastropods have been used for oil lamps, the oil being poured in the aperture of the shell, and the siphonal canal serving as a holder for the wick.
      • In Christianity, the scallop shell is considered to be the symbol of Saint James the Great, see Pecten jacobaeus.
      • In Hinduism left-handed shells of Turbinella pyrum (the sacred shankha) are considered to be sacred to the god Vishnu. The person who finds a left-handed chank shell (one that coils to the left) is sacred to Vishnu, as well. The chank shell also plays an important role in Buddhism.
      • Cowries have often been considered to be symbols of female fertility. They were often treated as actual fertility charms. The dorsum of the shell resembles a pregnant belly, and the underside of the shell resembles a vulva. In the South Indian state of Kerala, cowries are used for making astrological predictions.
      • In the Santería religion, shells are used for divination.
      • The Moche culture of ancient Peru worshipped animals and the sea, and often depicted shells in their art.
      • In Christianity, the top of the Sand Dollar represents the Star of Bethlehem that led the Wise Men to the manger of Christ. Outside the "star" you will see the Easter Lily, a sign of Jesus' Resurrection. There are four holes that represent the holes in the Lord's hands and feet. The center hole is the Wound to His Sacred Heart by the spear of Longinus. On the other side of the sand dollar, you will see Poinsettia. Lastly, if you break open the sand dollar, five doves will come out, the doves of Peace and Joy.
      • Shell necklaces have been found in Stone Age graves as far inland as the Dordogne Valley in France.
      • Seashells are often used whole and drilled, so that they can be threaded like beads, or cut into pieces of various shapes. Sometimes shells can be found that are already "drilled" by predatory snails of the family Naticidae. Fine whole shell necklaces were made by Tasmanian Aboriginal women for more than 2,600 years. The necklaces represent a significant cultural tradition which is still practised by Palawa women elders. The shells used include pearly green and blue-green maireener (rainbow kelp) shells, brown and white rice shells, black cats' teeth shells and pink button shells.
      • Naturally-occurring, beachworn, cone shell "tops" (the broken-off spire of the shell, which often has a hole worn at the tip) can function as beads without any further modification. In Hawaii these natural beads were traditionally collected from the beach drift in order to make puka shell jewelry. Since it is hard to obtain large quantities of naturally-occurring beachworn cone tops, almost all modern puka shell jewelry uses cheaper imitations, cut from thin shells of other species of mollusk, or even made of plastic.
      • Shells historically have been and still are made into, or incorporated into, necklaces, pendants, beads, earrings, buttons, brooches, rings, hair combs, belt buckles and other uses.
      • The shell of the large "bullmouth helmet" sea snail, scientific name Cypraecassis rufa, was historically, and still is, used to make valuable cameos.
      • Mother of pearl from many seashells including species in the family Trochidae, Turbinidae, Haliotidae, and various pearly bivalves, has often been used in jewelry, buttons, etc.
      • In London, Pearly Kings and Queens traditionally wear clothing covered in patterns made up of hundreds of "pearl buttons", in other words, buttons made of mother-of-pearl or nacre. In recent years however, the majority of "pearl buttons" are imitations that are made of pearlescent plastic.
      • Abbott R. Tucker & S. Peter Dance, 1982, Compendium of Seashells, A full color guide to more than 4,200 of the World's Marine shells, E.P. Dutton, Inc, New York, .
      • Abbott R. Tucker, 1985, Seashells of the World: a guide to the better-known species, 1985, Golden Press, New York, .
      • Abbott, R. Tucker, 1986, Seashells of North America, St. Martin's Press, New York, .
      • Abbott, R. Tucker, 1974, American Seashells, Second edition, Van Nostrand Rheinhold, New York, .
    Wikipedia
  • What Else?

    • Seashell

Extras