Hawaiian Shells and Cowrie Currency
Money cowries (Cypraea moneta) are small mollusks that live in the tropical waters of the Indian and Pacific Oceans. Their beautiful shells have been featured in ritual practices and incorporated into clothing and jewelry for thousands of years in African and South Asian cultures. Symbolically they were often associated with notions of womanhood, fertility, birth, and wealth. The Egyptians considered them to be magical agents and also used them as currency in foreign exchange transactions. Archaeologists have excavated millions of them in the tombs of the Pharaohs. In the thirteenth century, cowrie shells were brought to Africa from the Maldives in the Indian Ocean. They showed up in Egypt, then across the Sahara in the western Sudan region. Later, they were brought in by Dutch and English traders through the Guinea Coast ports of West Africa. The Europeans were astonished that the Africans preferred cowrie shells to gold coin.
Cowries were used in many other ways like bride wealth, payments for fines, divination, initiation into secret societies, and funerals. They were an important part of burial rituals in ancient China. When an emperor of China was buried, his mouth was stuffed with nine cowries. Feudal lords had seven, high officers five, and ordinary officers three. Common people generally had their mouths stuffed with rice, but if a commoner had some wealth, the last molar of each side of the mouth was supported by a small money cowry. This was to ensure that the dead had plenty to eat and spend in the afterlife.
Hawaiian Shells and Influence
Mollusks first made their appearance 500 million years ago, and their shells have played an important role in many cultures throughout the world. They have influenced man in art, architecture, trade, music, medicine, communication, and religion. They have been weighed, measured, sliced and cataloged by scientists. And archeologists have shown us how shells were used for containers, tools, ornaments, currency, and jewelry.
Shells were the earliest forms of currency used in many countries. The Chinese were the first people to use the cowrie shell as currency. Examples of other country’s native money-strands are found in New Guinea, the Melanesian islands, and Africa. The acceptance of this shell as a type of currency was so strong that the first oval metal coin minted in the Greek colony of Lydia around 670 B.C. was modeled after the cowrie. Hard clamshells and whelks were the shells used to make North American Indian wampum. Eastern Indians also used the tusk shell as a trade shell. Beads and other ornaments were traded all over the Andean region. Chumash Indians of California also made shell beads that they used as money. The name “Chumash” literally translates ‘bead money makers’.
Man has long been inspired by the graceful symmetry and beauty of shells. Archaeological diggings at many ancient sites have produced shells and artifacts in the design of shells. Phoenicians, Greeks, and Romans used the shell’s shape as part of their building design and decor. Architecture has been profoundly influenced by the symmetry of molluscs, with the Guggenheim Museum being a classic example. Many great artists were so inspired by the beauty, diversity and design of the shell, that they incorporated them into their masterpieces.
Hawaiian Shells and Shape
The mantle helps in the formation of the shell’s external features, such as ribs, spines, and grooves. For some species, these features provide protection from predators, added strength, or assist in burrowing. Shells of creatures like the nautilus have complex internal structures, such as multiple chambers containing water and gas that allow the creature to adjust its buoyancy. Most gastropods have coiled shells in the form of a logarithmic spiral, the only form of a coil that can both increase in size and retain its shape. Such an architecture is an efficient way to maintain strength while retaining the compactness of the shell. Some mollusks cement old discarded shells and other sea floor debris to their own shells. They use this technique as a means to camouflage themselves from predators, and to prevent sinking into soft sand or mud. While many mollusks have shells for protection from predators and environmental stresses, shells also have their disadvantages. Shells are permanent structures that mollusks must carry around for the rest of their lives, and its weight could slow the creature down. Some mollusks, such as the squid and octopus, have evolved by eliminating shells altogether.
Shell shape is a product of evolution which is greatly influenced by local environment and type of sea floor. A shell that is low and wide might indicate strong waves or many predators. A thinner, more spherical shell probably comes from deep water, or areas around the north and south pole that are poor in calcium (unlike rich tropical waters). On hard sea floors, crawling gastropods have coiled shells or flat, saucer-like shell cases that allow them to retreat into the shell when in danger. On a sandy or rubble strewn surface, shells have expanded shell edges that help stabilize the mollusk with its opening facing down. In calmer waters, sculpted features such as spines increase the volume of the shell, making the mollusk look more formidable against predators. This also increases the surface area of the shell, allowing other marine organisms to settle on the mollusk’s shell surface, serving as a physical and chemical camouflage. For burrowing in soft muddy or sandy surfaces, some mollusks have evolved smooth, long, tapering shells. Many molluscs are able to withdraw far enough into their shells to be beyond the reach of predators. Others are able to block their apertures with a hardened plug called an operculum.
Environmental changes, injuries, or abnormal conditions of the mantle are often reflected in the shell they form. When the animal encounters harsh conditions which limit its food supply or otherwise cause it to become dormant for a while, the mantle often ceases to produce the shell substance. When conditions improve again and the mantle resumes its task, a ‘growth line’ is produced extending the entire length of the shell. Patterns and colors on the shell after these dormant periods are sometimes quite different from previous colors and patterns. Each species of mollusk will build the external shell in a genetically predetermined shape, pattern, ornamentation, and color, while at the same time, giving itself a look all its own.
Hawaiian Shells and Formation
Appreciation of a shell’s beauty can only be enhanced by understanding a shell’s formation. The blood of a mollusk is rich in a liquid form of calcium. A soft, outer organ called the ‘mantle’ concentrates the calcium in areas where it can separate out from the blood, forming calcium carbonate crystals. The mantle continues depositing sheets of the crystal in varying thickness, shape, and orientation. Adjacent layers are often deposited with their crystal planes at right angles to each other greatly increasing the strength of the shell. The shell grows as the animal inside adds its building material to the leading edge near the opening. This causes the shell to become longer, wider, and stronger to better accommodate the growing animal inside.
The mantle orchestrates the designs and colors of the shell. Production of new shell material is influenced by several factors: sexual hormones, intrinsic rhythms, diet, acidity and temperature of water. Colors in shells are derived from organic pigments found in their food. Glandular cells collect these pigments, mix them with fluid calcite, and set this substance into the outer shell before it hardens. There are four main pigments that produce the many colors seen in shells: yellow carotenoids, black melanins, green porphyrins, and blue and red indigoids. Most color cells are located along the front edge of the mantle where new shell material is added. A straight color line or ray is formed when the color cells remain in the same position as the shell grows out. If color pigment production continually starts and stops, a pattern of dots or dashes is drawn on the shell. If the color cells actually migrate to one side, a slanting trail of color is produced. Other kinds of behavior by color cells can produce circles, triangles, and other shapes. Mollusks within a particular species have basic colors and patterns that are genetically inherited, but natural variation, like different hair color among people, gives each shell a character of its own.
