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Treasures of the Sea:

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Shells of the Turks and Caicos Islands
Story and Photos by Richard Ground

Among the many exciting things about holidaying on a tropical island are the strange and beautiful shells that you can find on the beach or when out snorkeling. The Turks & Caicos Islands are no exception, and observant visitors will find a rich and wonderful world awaiting exploration. The serious collector needs a good field guide, and several are available on-island, but for those who just want an overview, this is the first of three articles about the shells of the Turks & Caicos Islands (TCI).

Seashells are produced by molluscs, and for the casual collector there are two main types, gastropods and bivalves. The gastropods are sea snails, and they produce the familiar spiraling shells. The bi-valves, on the other hand, are composed of two flat shells held together by a ligament, and their remains are often found on the beach as single, flat valves. Of course, as with everything, there are exceptions. Limpets, those conical shells which cling tightly to rocks, are really primitive gastropods which have not yet begun to grow their shell in the spiral tube typical of the class. In this article, I will begin exploring some of the typical gastropods of the TCI, grouping the shells according to their families.

Conch shells

The most obvious group are the Conchs, which are members of the Strombidae family. Everyone is familiar with the huge Queen Conch (Strombus gigas) [see cover photo], and a local treat is eating it in one of the many delicious ways that it can be prepared for the table. But there are four other species which inhabit our waters, and all are much smaller. The Milk Conch (Strombus costatus) is half the size of the Queen Conch, and its interior and lip are a pure, milky white. The Hawk Wing Conch (Strombus raninus) is only three inches at most. From the back it looks a little like a frog (indeed its scientific name derives from the Latin word for frog), and from the front its flaring lip gives it a harp shape. The Rooster Tail Conch (Strombus gallus) gets its name from the upward extension of its flared lip, which can add an inch to its three to four inch shell. The Fighting Conch (Strombus pugilis) occurs in the Caicos Islands, and is the same species as that found in Florida.

Helmet shells

Another spectacular family of large shells is the Helmet family (Cassidae). The larger species are often about the same size as Queen Conchs, and are sometimes mistakenly referred to as “Conchs,” but they are quite different. They do not have the flaring outer lip, so typical of members of the conch family, but instead have a thick, glossy “shield” on the inside of the aperture on the bottom of the shell. This can be carved into cameos, and so they are sometimes called “cameo shells.”

cowrieThere are three species of the larger helmets in the Caribbean, all of which can be found in the TCI. In diminishing order of maximum size they are: the Emperor Helmet (Cassis madagascarensis), which can reach 14 inches; the King Helmet (Cassis tuberosa); and the Princess or Flame Helmet (Cassis flammea). Three species of smaller Helmets, often called “Bonnets,” are also found in the TCI — the handsome Reticulated Cowrie-Helmet (Cypraecassis testiculus); the smooth form of the Scotch Bonnet (Phalium cicatricosum); and the small Woodlouse (Morum oniscus).

Cone shells

For me, the most magical of the shells found here are the Cones. They are aptly named, for the spiraling tube of the shell is flattened to create a perfect cone, with the opening running all along one side. They are predators that catch their prey by injecting them with poison, and the sting of some species in the Indo-Pacific region can be fatal to humans. While ours are not lethal, two of the larger species — the Crown Cone (Conus regius) and the Alphabet Cone (Conus spurius) are said to be able to inflict a painful wound. You are not likely to find either on the beach — the Crown Cone lives out on the reef, while the Alphabet Cone is rather rare here (although common in Florida).

What you will find on the beach in great numbers are small white cones, some of which are smooth while others are covered in warty lumps. These are two forms of Conus jaspideus. You may also find the Mouse Cone (Conus mus) — when fresh this is a beautiful olive green, but those that have been on the beach for a while turn pink. If you are really lucky you may find the small Conus jucundus, whose glossy, inch-long shell is mottled brown and white, with a purple aperture. And that is not all . . . mysteries lurk in these waters, and the small, pale-yellow cone that occasionally washes up on one special beach in Grand Turk may well be a new and previously unknown species.

Olive shells

Olive Shells are a bit like Cones, in that they are elongated and have the aperture down one side. We only have two species — the Netted Olive (Oliva reticularis) and the tiny Common Rice Olive (Olivella floralia). Olives live in the sand, and have a beautiful, highly polished gloss to their shells. In the Caicos Islands, the Netted Olive (which is about an inch and a half long) lives up to its name, having a brown net-like pattern on the shell, but in the Turks Islands the common form is a brilliant, pure white. This form is uncommon elsewhere, and is sometimes called the Pearl Olive, because of its beauty. The Rice Olives are abundant, and look just like grains of rice. They are never more than half an inch long.

Cowrie and Trivia shells

Cowries have a particular tropical lure to them. Magically glossy, Native Americans treasured them; Mediterranean specimens have turned up in bronze age graves in Britain; and some Pacific Islanders have used them as currency.

cowtriThere are three species in the TCI. The large Measled Cowrie (Cypraea zebra) is (at three to four inches long) the most spectacular, and the rarest, but the smaller inch-long Yellow Cowrie (Cypraea spurca) and Atlantic Gray Cowrie (Cypraea cinerea) are more common. All live on shallow coral reefs.

Much commoner, and also much smaller, are the tiny Trivia. Although a different family from the cowries, they have the same shape and toothed aperture. It requires a sharp eye to spot the quarter inch Four-spotted Trivia (Trivia quadripunctata), although its lovely, bright pink colour helps catch the attention. The Coffee Bean Trivia (Trivia pediculus), is larger, at half-an-inch, and looks remarkably like its namesake.

The Common Atlantic Bubble (Bulla striata) also resembles a Cowrie from the back, but its aperture is not toothed, being smooth on the inside and having a thin outer rim. This mottled brown, unprepossessing shell is abundant on our beaches.

Murex shells

Murex Shells were famous in antiquity for producing purple dye for the ceremonial robes of Roman emperors. All are highly carnivorous and prey on other mollusks, drilling through their shells with their radula, which is a sort of hardened tongue.

Common in the TCI, the Apple Murex (Phyllonotus pomum), has a robust, thick shell, which can reach five inches long. Fresh specimens are usually heavily encrusted with marine growths, but underneath the shell is a mottled brown, with delicate scales and fluted spines. They last a long time on beaches, where they eventually fade to white.

A smaller, more delicate Murex is the Hexagonal Murex (Muricopsis oxytatus), a spiny little shell of about an inch. The Little Aspella (Dermomurex paupercula) is about the same size, but it lacks the spines and tends to be covered in encrustations. The Blackberry Drupe (Morula nodulosa) look just like its namesake, but is only about half-an-inch long.

shell11Murex & Rock shells

The Rock Shells are a distinct sub-family of the Murex. The largest is the spectacular Wide-mouthed Purpura (Purpura patula), which lives attached to cliff faces around the tide line. Outside it is worn and dull, but its huge aperture (used to accommodate a large foot to anchor it firmly) is a glossy, salmon pink. The two other Rock Shells, the Rustic Rock Shell (Thais rustica) and the Deltoid Rock Shell (Thais deltoidea) can both attain two inches, but are usually smaller, and covered in encrustations.

Triton shells

Tritons belong to the family Ranellidae (which means “frog-like”), and they tend to be smallish, warty brown shells. The exception is Triton’s Trumpet (Charonia variegata) which is smooth and pointed, and can reach 18 inches in length. At that size it is the largest shell found in the TCI. However, you would be lucky to find something that big, with six inches being the average. If the tip is cut off they can be blown like a trumpet, and if you go to the Trevi fountain in Rome you can see the sea god, Triton, blowing one (hence the name). But the Arawak Indians, who were the earliest inhabitants of these islands, also used them in that way, and a perfect example of this, nearly 1,000 years old, was found in an excavation on Grand Turk (see Times of the Islands, Winter 2003/04).

The other Tritons are smaller — the Hairy Triton (Cymatium pileare) can reach three inches, and gets its name from the hair-like frills on its periostracum (which is a soft, outer covering which some shells have when alive). The smaller Dwarf Hairy Triton (Cymatium vespaceum) is more inflated and inhabits deeper waters. The common Gold-mouthed Triton (Cymatium nicobaricum) is a mottled white, but has a gorgeous golden-red aperture. The Knobbed Triton (Cymatium muricinum) is brown, with a great smear of creamy white enamel, like glazing on a cake, around its aperture. Its empty shell is a great favourite of land hermit crabs. The Neapolitan Triton (Cymatium parthenopeum) looks similar from above, but at over two inches is larger, and is distinguished by a long siphonal canal, which is the “snout” that protrudes from the front of some shells.

The smallest of the Tritons is the tiny Lip Triton (Cymatium labiosum), while the largest of the knobby ones is the Angular Triton (Cymatium femorale) which can attain a spectacular eight inches. It has a triangular aperture and a pagoda-like spire, and is a beautiful dark brown, marked with white. It is much sought after, but rarely found whole. It seems to fracture easily, and while fragments are common on beaches fringed by Turtle Grass beds, complete shells are exceptional.

coralsnailsCoral snails & Frog-shells

Similar in appearance to Tritons are the Frog Shells, of which only the St. Thomas Frog Shell (Bursa thomae) is found regularly in the TCI. It has a pointed spire, which is laterally flattened, and a distinctive lavender aperture, the rim of which projects slightly like a calcareous frill. The larger Granular Frog Shell (Bursa granularis) is similar in shape, but lacks the colourful aperture.

Coral Snail shells

The Coral Snails also have colourful apertures. The Caribbean Coral Snail (Coralliophila caribbaea) has a deep violet aperture, while that of the Short Coral Snail (Coralliophila abbreviata) is a creamy orange. However, these small shells (which live and feed on Sea Fans) are usually heavily covered in limey encrustations.

Tulip and Latirus shells

The family Fasciolariidae includes the showy Tulips and the knobby Latirus shells. A large Tulip can exceed six inches, and has a variegated exterior patterned in brown or gray and a glossy, light orange interior. The animal is highly predaceous, and cannibalism on its own species is common.

latriusThe Latirus shells are smaller, and usually knobby or ridged. The largest, at up to three inches, is the Carinated Latirus (Latirus cariniferus) which is a deep yellow, with brown stripes in the valleys between raised ribs. The White-spotted Latirus (Leucozonia ocellata) has a similar shape, but averages around one inch, and is a light brown with white knobs. The Chestnut Latirus (Leucozonia nassa) is a deep chestnut brown, with yellowish knobs, but in the Turks Islands the dominant form is entirely smooth and fairly small, at around one inch. The baby of the family is the tiny Key West Latirus (Dolicholatirus cayohuesonicus), which is a uniform tan brown, rarely exceeding half an inch.

To be continued in Summer 2004 Times of the Islands.

CLEANING YOUR SHELLS

shellcollectionThe richness and diversity of the shells of the TCI can seem endless, as can the task of sorting and cleaning those you collect! Many that you find on beaches will be worn and sun-bleached, while fresher ones may still be covered in the calcareous concretions that cover some species in life. This can be removed using a dental pick or similar instrument and I find a small hobbyist’s drill useful.

Often shells will be covered in green algae, which can even grow in the fabric of the shell itself. A short soaking in a weak bleach solution will remove that and generally freshen up the shell. In some cases, a quick dip in 10% muriatic acid will revive a dull looking shell, but you need to be careful for the acid eats away both encrustation and shell indiscriminately.

Once you have the shell clean, rub it with mineral oil or a household polish such as Pledge, which is light and penetrating, to bring out the colours and preserve the shine. All this can be hard and painstaking work, but it is worth persevering, because by cleaning and then identifying your finds, you can turn a heap of old shells into a meaningful and beautiful collection.

Richard Ground has been Chief Justice of the Turks & Caicos Islands since 1998, recently leaving to take up an appointment as Chief Justice of Bermuda. When not at work, his main interest is wildlife photography, with an emphasis on birds. Shells are a new departure; describing himself as an insatiable collector and cataloguer, he says it was not long before he was sorting his finds and searching for rarer and more beautiful specimens.



2 Comments

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Clinton Care
Jul 10, 2010 2:14

Hi Richard,
I been looking for a seashell shop that sell seashells in Turks & Caicos Islands, but I find it difficult to find the shop by email address.
Can you please help me by send me the email address of a seashell shop that sell seashells in Turks & Caicos Islands, to other countries as New Zealand.
I lives in New Zealand and I am interested in buy the helmet seashells and triton seashells from Turks & Caicos Islands.

My email address: subtropicalslorikeet@hotmail.com

Please reply

Yours Sincerely

Clinton Care.

liz kofsky
Dec 19, 2013 11:51

What is the best beach for shelling. Going in 2 weeks on a cruise to Turks and Caicos?

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Marta Morton, owner/operator of Harbour Club Villas (www.harbourclubvillas.com) took this photo of the native Turks & Caicos rock iguana on Bay Cay. This endemic animal is being threatened by the invasive green iguana. See article on page 36.

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