A seashell or sea shell, also known simply as a shell, is a hard, protective outer layer usually created by an animal that lives in the sea.
Most shells come from soft-bodied mollusks. Snails, clams, oysters, and others need the hard protection of their shells. This tough outer covering protects the tasty body hiding inside. Other animals, such as crabs and lobsters, also make a tough outer covering, but here we focus on mollusk shells.
Seashells may be univalved (as in snails) or bivalved (as in clams), or they may be composed of a series of plates (as in chitons).
A shell is composed largely of calcium carbonate secreted by the mantle, a skinlike tissue in the mollusk’s body wall.
Specialized cells in the mantle build the shell using proteins and minerals. These are secreted—released into the space outside the cells. There, the proteins create a framework that provides support for the growing shell. The proteins in the framework also determine which minerals are used in specific parts of the shell.
Shells have been around for more than 500 million years.
Shell collecting is a practice of finding and usually identifying the shells of mollusks, a popular avocation, or hobby, in many parts of the world. These shells, because of their bright colours, rich variety of shapes and designs, and abundance along seashores, have long been used for ornaments, tools, and coins. Aristotle and Pliny the Elder wrote extensively about them. In the ruins of ancient Pompeii and in a crypt in a Mayan pyramid in Yucatán, shells were found that may be the remains of ancient collections.
When it comes to the largest seashell in the world – the Australian Trumpet is said to be the largest. They are created by gigantic sea snails from the Gastropod mollusk family, Turbinellidae. These incredible creatures have been roaming the ocean waters since the 1600s and are highly sought after by collectors everywhere. This is because of their unique shapes, colouring, and sizes. Their shells are known to grow up to 91 cm (or 35 inches) in length and weigh around an impressive 18 kg. These are massive measurements when it comes to some of the more traditional seashells found around beaches.
A newly discovered snail species is the smallest yet found on land – Angustopila psammion, discovered in cave sediment in northern Vietnam, has a shell just 0.48 millimetres high and a shell volume of only 0.036 cubic millimetres.
The rarest seashell in the world is the white-toothed cowry. It is known from just two specimens, the second of which turned up in 1960, and is thus the most coveted species among conchologists. Its only recorded locality is the Philippines’ Sulu Sea, where a fish was caught during the 1960s whose stomach was later found to contain a white-toothed cowry.
The regal Queen Conch Shell has long been considered one of the most beautiful types of shells. Growing up to 10 inches in length, the Queen Conch is one of the largest seashell species in existence and comes from the Strombidae family of shells which are native to the Caribbean Sea.
Of the more than 100,000 known species of shells, one of the most rare and the most valuable for many years was Conus goriamaris, the glory of the sea cone shell. Like many cone shells, this large, slender cone shell is found in the Pacific and Indian Oceans. Fine, chestnut heiroglyphic-like markings cover the shell of this animal in two or three bands.
In 1969, the habitat of conus gloriamaris was discovered, and since then hundreds have been collected. The value of the shell has dropped significantly since then, and it is no longer the world’s most expensive shell. However, the glory of the sea is still highly collectible, both for its shape and coloring and also for its history.
The world’s best beach for finding shells is situated on L’Haridon Bight in Shark Bay – Shell Beach in Western Australia is home to billions of tiny coquina bivalve shells, deposited here over 4,000 years ago. The result is a sixty-kilometre long snow-white beach, lapped by an aqua blue sea, covered in shells that go down 6 to 10 metres.
The largest human image of a seashell has 1,093 participants, and was achieved by The Beaches of Fort Myers & Sanibel (USA) as part of National Seashell Day at the Outrigger Beach Resort on Fort Myers Beach, Florida, USA, on 21 June 2018. The final seashell measured approximately 49.27 m (161 ft 8 in) long by 22.25 m (73 ft) wide. The gathering for National Seashell Day also functioned as a non-perishable food drive. The United Way of Lee, Hendry, Glades and Okeechobee Counties collected over 129.27 kg (285 lb) of food, which was donated to the InterFaith United Way House.
Seashell is an off-white color that resembles some of the very pale pinkish tones that are common in many seashells. The first recorded use of seashell as a color name in English was in 1926. In 1987, “seashell” was included as one of the X11 colors.