August, 2010
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Seashells occupy a unique place in the natural world, and no other animals are as widely collected. The word seashell is most often used to mean the shells of marine mollusks, but it can also be used to mean the shells of a wide variety of other marine animals. Mollusks all have soft bodies and they have a hard, protective outer layer. In most cases the shell is the external skeleton of an animal without a backbone, an invertebrate. People have skeletons on the inside of their bodies, and mollusks have their skeletons on the outside to protect them from predators, strong currents and storms, it also helps to camouflage them. Seashells are made of calcium just like our bones.
There are 100,000 species of mollusks worldwide. Snails make up 80,000 of them. Half of them are marine snails and the others are fresh-water and land snails. Bivalves are mollusks that have two shells like clams, oysters, mussels and scallops which are less numerous than snails, only 10,000 species, but are of greater economic value. Seashells are most often found on beaches. In most places its O.K. to pick up “empty” seashells at the beach, but ask the local lifeguard to be sure. ”Empty” means the shells don’t have any creatures living in them or using them as a home. Sometimes a small snail or hermit crab or other animal will be using a larger abandoned shell as a home. If you find the shell is occupied, leave it where you found it. Infants: Seashell Mobile - Use small and medium sizes seashells with holes worn in them. Cut string into a variety of lengths. Tie one end to an embroidery hoop and the other end through hole in shell. Arrange shells so they can hit each other when hung over a crib. Encourage the infant to listen to the sound they make when you hit them. Could changing the thickness of the shells change the sound? If you do not live near the beach ask the children’s parents to bring in some shells from their vacation. Toddlers: Seashell Pets - Shells can be bought from a local craft store along with “googly eyes.” Toddlers love making these animals. Glue the eyes on the seashell. Encourage the children to make up and tell a story to go with the animals. Preschool: Seashell Collections – Have the children go on a field trip to the beach to collect seashell. Give each a collection box, (an egg carton) so that they can collect their own shells. If there is no beach near by send the collection box home and ask parents to fill it with some shells from a family vacation. When they return to the classroom have the children make a dry seashell collection in a paper egg carton, and a wet seashell collection in a Styrofoam egg carton; add some water. Observe the wet seashells. Do they sparkle? Are the colors more vivid than the dry ones? Feel the texture, are they slippery? Do they feel different than the dry ones? Have the children describe them and then write an experience chart on the comparisons. Classify and sort them according to size, color, and shape finding the biggest to smallest, and arrange the shells in size order. Seashell Rhyme – “She sells sea shells by the sea shore.” by Terry Sullivan |
