About Seashells

About Seashells

Seashells belong the kingdom Mollusca. Most Mollusca are soft fleshy slug like creatures that have an hard external skeleton type structure to help protect them. Mollusca can be found in both salt and fresh water, as well as on the land (snails). In the oceans, this structure is known as a seashell. There are over 60,000 known species of Mollusca. Mollusks are adapted to live practically anywhere. From the most barren sand bottom to the most elaborate coral reef. Shells have been in existence for millions of years and have been recorded in history in almost every journal. Sanibel Island is one of the best places to gather seashells on the beach in the world.

Seashells are technically just the outer exoskeletons of a large varied group of animals called mollusks.  Similar to a human skeleton growing along with us, a seashell grows with the mollusk inside.  The animals form protein and mineral based secretions that when secreted a thin layer is added to the seashell.  Just like a human is unable to shed their skeleton, a seashell cannot also.  As the mollusk grows the seashell must grow to accommodate it.  They are made mostly of calcium carbonate.  Sometimes you will find a seashells with a Hermit Crab inside.  This is not the actual creator of the shell but a creature and inhabited it after the mollusk inside died