10 Facts About Seashells

10 Facts about Seashells

A brief introduction.

What is the difference between malacology and conchology? The study of a mollusk-animal creates its shell is called malacology; while conchology is one division of malacology that study of mollusk shells. Some mollusks have no shells. There are five main classes of marine mollusks: Bivalves (two valves), Gastropods (generally coiled shells), Polyplacophora (chitons), Scaphopods (tusk-shaped shells) and Cephalopods (octopuses, squids & cuttlefishes).  Say the number of all different species are somewhere between 50 – 70 thousands.

1. The Purple Sails and Murex Shells

The Purple Sails and Murex Shells

 In ancient times, the Phoenicians from Tyre city in the east Mediterranean discovered how to get a natural purple dye. Murexes as Bolinus brandaris, Hexaplex trunculus, and Thais haemastoma became a source for making the rich purple dye. These mollusks were abundant along the coastline of Phoenicia (Lebanon these days). The whole process of producing the dye took over 10 days and had a few stages. To get 1 pound of the dye it needed 60 thousands of murex mollusks. Huge mounds of crushed murex shells between Mount Carmel and Sidon (Lebanon) are still the evidence from that epoch. Although other Mediterranean countries tried to know the secret of the Tyrian purple dye, they couldn’t do it. Only royalty was able to use Tyrian purple. It said Cleopatra’s flagship had the purple sails.

2. Cowries and Porcelain

Cypraea lurida

Cypraea lurida.

 Cypraea pantherina

 Cypraea pantherina.

 Cypraea or Cowries are recognized marine mollusks for their super-smooth, glossy egg-shaped shell. Archaeologists found Cypraea lurida and Cypraea pantherina – the panther cowry in Egyptian pyramids and in the ruins of ancient Pompeii.  In the earliest European cultures, people used them as ornaments and as religious symbols.  Ancient Romans called cowries Porculi (Little pigs). Centuries later, they were named Porceletta or Porcelana shells in Europe. When Marco Polo brought delicate glossy porcelain ware from China in the 13th century, its surface reminded of porcelain shells. The fact, in France, cowries are called Porcelaines nowadays.

3. Many bills have been paid out with the Money Cowries

Money Cowries

 Different seashells served people as currencies in the many parts of the world for many centuries. Two species of the Cypraeadae family – Cypraea moneta and Cypraea annulus or Monetaria annulus (more known as the Money Cowries) could be called the “international” currency. These small, glossy and smooth seashells first came into use as money in a few regions of modern China, about 2000 B.C. Then, centuries later, some Chinese metal coins had a shape of a Cowry shell as well. A main, natural “mint” of money Cowries came from the Maldive Islands which are placed to the south-west of India.

Cypraea moneta

Cypraea moneta.

There Cypraea moneta dwells in a great number. It was easy to collect millions and millions of Maldives’ cowries.  Since the 9th century, Arab merchants used this natural currency in their deals in India, China, and Africa. Slaves, Ivory and even gold were purchased for cowries in Africa. By the middle of the 17th century, the Europeans controlled all the trade on the sea. Their ships sailed from India through the Maldives to take tons (millions) of the free money Cowries. The idea was, to load the shells instead of the ship’s ballast. And then they spent that “money” ballast on slaves on the west coast of Africa. Shortly afterward, however, a “hyperinflation” destroyed the money Cowries value in Africa. A funny fact, at the beginning of the 19th century an Englishman living at Cuttack in the north-east of India paid out for the erection for his bungalow in cowries; 6 million ones were required. Furthermore, 1 church built in India, costing 160 million cowries.  It was the equivalent of £4000 sterling at that time.   It is noteworthy some other seashell species were used as money in different countries too.

4. Bulikula and Cannibals

Cypraea aurantium

Cypraea aurantium.

 Captain Cook’s circumstances became a “fresh breeze” for conchologists. New, unknown seashells were brought back to England. Before, Cook’s epic voyages European collectors knew shells transported from the East and West Indian waters. They knew nothing about the Pacific Ocean species. A few specimens of Cypraea aurantium or Golden or Orange Cowry were exchanged by Cook’s crew-members from the natives in Tahiti.  Each of those Golden Cowries has a small bored hole in one side. The natives of Tahiti decorated their dresses with these beautiful shells and highly prized them. They said all these Cowries were found far away from their home Island; they meant the Fiji Islands which were inhabited by “ferocious” cannibals of those seas. So, Captain Cook and his people had to be content with these boring ones. For many years after Cook, most Cypraea aurantium specimens reaching collectors had holes.

Fijians called this orange cowry ‘Bulikula’.  Only high-ranking chiefs were allowed to wear the necklace of a single Bulikula and the necklace with two Bulikulas. For ordinary islanders this sea’s treasure was taboo. A much more poetic name for Cypraea aurantium is the Morning Dawn Cowry. And it is probably right (the author’s opinion).

5. Left-handed, sacred Indian Chank or a seashell that worth its weight in gold

Turbinella pyrum

Turbinella pyrum.

 Turbinella pyrum a common name is Chank shell has been used to serve to gods and people for millenniums. In India, it’s known as the Shankha. In Tibet, it’s named as “Dung-Dkar”. Hindus Lord Vishnu holds the sacred, left-handed Shankha shell in one of his left hands.


Vishnu uses shankha as the trumpet, as a sort of the “acoustic” weapon against demons. He also blows this shell trumpet to declare the victory of good over evil. When two Hindus marry, the bride has to put on a couple of Chank bangles instead of a wedding ring. Also, Chank trumpets are blown on a Hindus marriage to announce the event. At birth, a Hindu babe is presented with a necklace or a bangle-making of the Chank shell. In many cases, Chanks are still utilized by people too in many ways. Usually, a shell spiral is clockwise coil or “right-handed”, but sometimes, a shell has a counter-clockwise spiral or “left-handed”. Most specimens of Turbinella pyrum are heavy, thick and right-handed shells. The left-handed ones occur very rarely. Something like 1 by 100000-150000 thousand ones. So, this is a reason why every left-handed Chank is worth its own weight in gold.

6. Sea killers and savers for many people

 Conus marmoreus

Conus marmoreus.

Conus geographus

Conus geographus.

There are more than 500 species of the Cones or – Cone shells living in the tropical and sub-tropical seas. Collectors like these shells for their delightful patterns and colors. However, several species are deadly for men.  A mollusk has a harpoon-like tooth and manufactures a potent poison for the hunting of fish or other mollusks. So, human hands or feet can be an object for a cone’s attack. In most cases, people survive after this. But some cases ended fatally. Probably, Conus marmoreus and Conus geographus are the most poisonous among the Cones. Poison of the Cones has begun to be used in pharmacology. For example, Prialt (Ziconotide) is a powerful drug against chronic pains that helps humans.

7. The wonder shell and architecture

Thatcheria mirabilis

Thatcheria mirabilis.

Thatcheria mirabilis or just the Wonder shell was first brought to England from Japan by Charles Thatcher in 1897. Most expert conchologists at the time defended it as a nice fake. In their view, the shell had an unbelievable geometrical form as for a natural object. They were wrong. However, only in the 1930s, more specimens of T. mirabilis came to Europe. One of these beautiful seashells impressed Frank Lloyd Wright to design some of his famous buildings.

8. A Killer clam and the largest pearl in the world

 Tridacna gigas

 Tridacna gigas.

 Tridacna gigas is the biggest species of living bivalves in the sea. This giant clam can weigh up to 500 pounds and reach a length over 50 inches. Does Tridacna gigas really kills divers? There are different stories about careless divers whose feet or hands were caught by huge valves of this mollusk. However, we have no proof of this. Tridacna’s valves close slowly for this killing trick.

One interesting fact, the Pearl of Allah or the Pearl of Lao Tzu is the largest pearl in the world. Having a length of 9.4 inches and weighing 14 pounds, it was collected from the big Tridacna.

The Pearl of Allah or the Pearl of Lao Tzu.

One interesting fact, the Pearl of Allah or the Pearl of Lao Tzu is the largest pearl in the world. Having a length of 9.4 inches and weighing 14 pounds, it was collected from the big Tridacna.

9. Some collectors defeated by their priceless collections

Some collectors defeated by their priceless collections.

In the 17 – 19 centuries, being a shell collector meaning to be a very wealthy person. At that time, owning a seashell collection was like owning a full garage of sports cars these days. There was a fashion for polished sea shells in Europe in the 18 century. A shell polisher was the high-paid profession. Well, “Polished” even is not a very accurate term because many rare, prized specimens were “polished” almost beyond recognition.  A polisher rubbed/cut out a layer by a layer from a shell surface until its pearly gleam. After this sort of “deep cleaning”, seashells lost their natural beauty. Today removing a mollusk out of its shell and then cleaning the shell off the marine growths is a common practice for collectors.  However, any “deep cleaning” is a crazy idea for serious conchologists. Yes, polished shells are still selling as nice sea souvenirs for tourists. Anyway, these ones cannot be called ‘collecting specimens’.  On the contrary to Europeans and Americans, many Japanese collectors prefer to keep seashells in their very “natural” state. They just remove the mollusk but keep all marine growths adhering to the shell.

10. The largest two seashells in the world

Syrinx aruanus

Syrinx aruanus.

Tridacna gigas

Tridacna gigas.

The biggest of Bivalve is Tridacna gigas. The world-recorded specimen is 54 inches. The largest of Gastropod is Syrinx aruanus – the Australian trumpet or false trumpet. The world-recorded specimen measures about 36 inches (91cm) in length.

11. Bonus but no fact

In spring of AD 40, the 3rd Emperor of the Roman Empire Gaius (known as Caligula) was going to conquer Britannia. When his troops reached the English Channel, the Emperor ordered soldiers to collect seashells as “spoils of the sea” and then to bring them to Rome. Historians have had a lot of theories what Caligula’s order was about really. But maybe the Emperor was the first crazy seashell collector? Who knows?