How Are Shells Created?

Along the beaches of the world, many people spend time combing the shoreline in search of seashells. These shells are typically the former exoskeletons of mollusk creatures like clams, mussels, snails and other shell fish. Shells are created from proteins and calcium carbonate in association with their mollusk counterparts.

  1. Exoskeletons

    • Seashells are actually the exoskeletons of many sea creatures in the mollusk family, according to the Scientific American website. The website states that seashells differ from the shells of a turtle because they grow outside the mollusk's body, while turtle shells are part of the turtle's skeleton.

    Components

    • Seashells are made primarily from calcium carbonate ions and a small amount of protein. They are formed as the minerals of the calcium grow over the protein later, according to the Scientific American website.

    Growth

    • As a mollusk's body grows, its shell must also grow to accompany the interior body. Some animals, like hermit crabs, transfer from one shell to another as they grow. However, most mollusks stay in the same shell for life. According to the Seashell World website, shells grow from the mantle of the mollusk. This layer secretes new proteins which bond with calcium carbonate to grow both outward and upward. The growth pattern of two shells is never exactly the same.

    Color and Pattern

    • Shells come in a wide array of colors and patterns, according to the Seashell World's website. This is primarily due to the diet of their animal counterparts. Mollusks' diets vary depending on water temperature. Warmer water is typically home to more colorful, patterned animals. This is due to the variety of food available in warmer climates. As a mollusk eats, pigments from the food are absorbed into the mantle layer. Cold water mollusks typically live in dark-colored shells

    Function

    • Seashells serve a variety of purposes for mollusks. Many ocean mollusks use their shells for protection and housing, according to the Seashell World website. Many land mollusks live in shells to help prevent water loss, which can lead to death. Other mollusks use shells as a tool for opening items and to help with movement, swimming and floating.