MOLLUSKS- seashellsSeashells 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.