Malacological Wonders of the Shell Museum Piran

Explore the part of the collection of the only shell museum in Slovenia

Tridacna gigasMagical World of Shells Museum

Let’s start with the largest

Tridacna gigas is the world’s largest clam – it can grow up to 1, 5 meters and weigh over 300 kilograms (661 pounds). Its shell is so large that it was used for christening babies, who can lay comfortably in the large shell.

These shells live from the eastern Indian Ocean to the western Pacific Ocean. Our Lisa, as we named her, is almost 1 meter and weighs a stunning 150 kg (330 pounds).

Pearl Puerto Princessa - replicaMagical World of Shells Museum

Puerto Princessa Pearl

Replica of the biggest pearl in the world. The story that is woven around this pearl is very adventurous, but most likely just a figment of the imagination.

In 2006 a Filipino fisherman’s anchor got stuck in the shell of a giant clam. As he was trying to get out the anchor he found inside the shell a big white stone. But the fisherman did not know that he had found an extremely valuable thing. 

He put the stone under the bed and touched it for good luck every time he went to sea. After some time he moved to another location and left the rock. Upon inspection, they found that the fisherman had left behind a pearl worth 100 million euros!

Syrinx aruanus periostracumMagical World of Shells Museum

Largest snail in the world is really hairy!

Syrinx aruanus is the largest living species of snail in the world. The largest specimen found so far measures 77.2 cm and is on display at the HMNS (Houston Museum of Natural Science). 

Composed of a type of protein known as conchiolin. It plays a big role in shell formation.

This furry coat on him is the outer layer of the shell - periostracum. 

Syrinx aruanusMagical World of Shells Museum

Syrinx aruanus (Australian Trumpet)

This species of snails can be found in the seas around Australia. The snail's shell is so large, hard and thick that it was used by the natives to transport water.

Monetaria moneta – Money cowryMagical World of Shells Museum

The most ancient currency of the world - this small snail!

It was used as a currency in Africa, China and India. Even its Latin name (Monetaria moneta) is linked to its use - moneta meaning 'money' in Latin. 

It cost 20.000 cowries to buy a slave in Borneo, while a vassal of great Burkina Faso king Moro-Nabe paid the annual tax of 1.000.000 cowries.

Monetaria annulus and Monetaria monetaMagical World of Shells Museum

Monetaria annulus

This is the second most sought after shell for trading – right after the money cowry. 

They strongly resemble in their appearance but can easily be distinguished by a yellow ring on the shells of Cypraea annulus. Cypraea annulus come largely from the islands on the east coast of Africa (Zanzibar and Pemba).

Monetaria annulus - bunnyMagical World of Shells Museum

The island of Pemba in the east coast of Africa is an interesting spot, where Cypraea annulus with extended mouth live. Because of the shapes of extensions, which are rabbit-ear like, they got their common name - rabbits.

CowriesMagical World of Shells Museum

Cypraeidae or cowries are a large taxonomic family with over 250 species. Members of the Cypraeidae family are night predators and spend their days hiding. The typical feature of all the cowries is their smooth and shiny shell. Cowries take care of their glossy shell themselves – their daily routine includes the polishing of the shell with their mantle.

Leporicypraea mappaMagical World of Shells Museum

Leporicypraea mappa (map cowrie)

All shells of L. mappa have a very interesting pattern. 

Pattern on mappa shells resembles old medieval maps with rivers and land.

Barycypraea fultoni massieri dorsalMagical World of Shells Museum

Barycypraea fultoni massieri

This is one of the rarest cowries in the world. It lives in deep waters around Mozambique and for some time it was only found by fishermen in fish stomachs.

Barycypraea fultoni massieri ventralMagical World of Shells Museum

Mona Lisa smile

Because of its inaccessible habitat it’s life and behaviour still remain something of a mystery until today.

Xenophora pallidula dorsalMagical World of Shells Museum

Xenophora pallidula

Xenophoras or carrier shells are not a large taxonomic family and only contain 22 species. 

These unusual marine snails have an interesting way of hiding in their environment - the animal cements small stones or shells located around its proximity to the edge of the shell as it grows.  Some snails get so »carried away« with collecting other stones and shells that one individual can be adorned by over 10 other species.

Xenophora mekranensis konoi ventralMagical World of Shells Museum

From the top, this shell does not resemble a snail, but when we turn the shell around, the structure of the snail shell is easily recognised and the mouth where the snail comes out of his/her/their shell. 

Xenophora mekranensis konoi dorsalMagical World of Shells Museum

Xenophora mekranensis konoi

Carrier snails could be called the first collectors. This one seems to be interested in corals – it has collected many solitary corals from the surroundings and cemented them into its shell to hide from predators.

Xenophora mekranensis konoi coralMagical World of Shells Museum

You can clearly see septa on this solitary coral. 

Bayerotrochus teramachiiMagical World of Shells Museum

Damaged shell?

Bayerotrochus teramachii (Teramachi's Slit Shell) Pleurotomariidae is a very ancient family, which has seen very little changes during millions of years. 

They kept some ancient features, such as the slit in the shell's last whorl. It might seem that the shell is damaged, but it is not. Through the slit visible here, the snail secretes toxins.

Lissachatina achatina dorsalMagical World of Shells Museum

Giant snails come from Africa

Lissachatina achatina (African giant snail) is the largest known land gastropod. The largest recorded specimen named Gee Geronimo measured 39.3 cm from snout to tail when fully extended, with a shell length of 27.3. It weighed 900 g (2 lb). Snail was collected in Sierra Leone in June 1976.

Lissachatina achatina ventralMagical World of Shells Museum

Like all land snails this goliath is also breathing air with simple lungs, which are placed in the snail's mantle cavity.

Papustyla pulcherrimaMagical World of Shells Museum

Green colour is rare amongst mollusc shells

Here is one amazing land snail Papustyla pulcherrima (Emerald green snail) from Island Manus in Papua New Guinea. 

Now sadly endangered due to logging and destroying of his habitat.

Livonia roadnightaeMagical World of Shells Museum

It all started with a Big Bump

This bump at the top of the shell is a huge protoconch (the first whorl snail builds in his larval stage) of about 15mm in diameter and it separates it from other volutids in genus Livonia. This marine snail is endemic to Australia. 

Livonia roadnightae (Roadnight's Volute) is carnivorous feeding on other invertebrate animals. It inhabits deep water around 20 - 350m.

Campanile lachesisMagical World of Shells Museum

Campanile lachesis - extinct heavy snail

Specimens of this size (50 cm), so well preserved, are extremely rare. The opening (where the snail crawls out of the house) ends with a beautifully preserved mouth, which is exceptionally preserved after 40 million years.

C. lachesis belongs to the family Campanilidae. This is a large family of large snails that lived in the Tethys primordial sea.

Campanile symbolicumMagical World of Shells Museum

The last survivor

Only one species of this interesting genus of giant snails (Campanile) still lives today - Campanile symbolicum. It lives in the cold shallow waters of South Australia and like its extinct relatives, feeds on algae. It grows up to 21 cm, but its shell is rough and looks as if it has already been petrified.

Aporrhais pespelicani ventralMagical World of Shells Museum

Pelican foot at the bottom of the sea?

The shape of the shell resembles a pelican's foot, hence the name pes-pelecani or the common name pelican's foot. Aporrhais pespelicani (Pelican's foot) is an endemic species of the Mediterranean Sea.

Aporrhais pespelicani dorsalMagical World of Shells Museum

Because they live on sandy seabed, they have developed long finger-like extensions, which prevent them from sagging into the soft bottom.

Aporrhais pespelicani cutMagical World of Shells Museum

When we cut open the shell we can see intricate columella – the vertical axis around which snail forms other whorls.

Pecten jacobaeus - shellsMagical World of Shells Museum

Pecten jacobaeus or Mediterranean scallop

It is native to the Mediterranean Sea, because of its size and asymmetrical shape, it makes it hard to mistake them for other species of scallops.

Pecten jacobaeus - eyesMagical World of Shells Museum

A living scallop has 20 eyes along the edge of the shell, but despite the strong »optics« it is not able to see well. It can only detect changes of light, which is sufficient for the scallop to escape. 

Pinna rudisMagical World of Shells Museum

Pinna rudis - Prepared for pandemic

Lesser known pen shell, which can be easily mixed with his bigger cousin noble pen shell (Pinna nobilis). Populations of Pinna nobilis are due to the small parasite Haplosporidium disappearing through the whole Mediterranean sea. But this species is somehow resistant to it. 

Pinna nobilis - shellsMagical World of Shells Museum

Let’s finish with an amazing clam from the Slovenian Sea!

Reaching the size of 100 cm or more, the noble pen shell (Pinna nobilis) is the largest European bivalve. 

Pen shells dig themselves 10 centimetres deep into sand and additionally attach themselves to the rocks under the sand layer with byssus threads. Because of the Haplosporidium parasite, now greatly endangered. 

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