Clockwise from top left: Strombus gigas, Telescopium telescopium, Chlamys senatoria,
and Harpa articularis. The shells, which are not shown to scale, are from the private
collection of Imelda and Edwin.
Shells: Jewels of the Sea
Seashells -- the hard, calcified outer skeleton of many mollusks, including snails, abalone, limpets, conch, nautilus, clams, oysters, scallops, and mussels -- are a world of their own. It was in the mid-1980s when we first became fascinated with these fabulous treasures from the deep. We fondly recall the days when we would pass by this nondescript handicraft factory near our former home in Manila in the Philippines. Workers at the factory would often spread an assortment of newly cleaned shells to dry by the roadside, waiting to be transformed into works of art. What caught our attention was not merely the art but the science of conchology. The beauty and variety of these shells were absolutely amazing!
With Tita Naty Somera and her sons Niño (far left) and Vladimir
(far right) during Imelda and Edwin’s visit to the Philippines in 2006.
We then became frequent visitors to Tribesmen Products, as this handicraft factory is known, and later became good friends with its owner, Naty Somera, and her husband, Joe. Tita Naty and Uncle Joe, as we fondly call them, would tolerate our forays to their warehouse, rummaging through newly arrived sacks of shells brought in by fishermen from all over the country. Tita Naty was especially helpful in supporting our growing interest by giving us deep discounts on our purchases. After all, she knew we were just students at the time. Finding a gem-quality specimen in the unattractive, often smelly, sacks was like finding a priceless treasure at an archeological dig. The stench of decaying mollusks still inside the shells could really be offensive, so the first thing we had to do every time we come home from our treasure hunt would be to take a long shower.
What was magical was that after we cleaned the raw shells, their true inner beauty was revealed. And to think that the animals that created these shells did it to protect their soft, fragile bodies. The forms, patterns, textures, and colors of the shells are mainly for camouflage and defense, but looking at them, one would say that they are indeed works of art in their own right.
Imelda and Edwin's collection in Manila, Philippines, in the late 1980s.
In 1995, after we moved to the U.S. East Coast, we joined the Boston Malacological Club, a non-profit organization of shell enthusiasts founded in 1910. Club members meet eight times a year, from October to May, at Harvard University's Museum of Comparative Zoology in Cambridge to catch up on the latest news, swap stories on shelling trips to Florida and the Caribbean, hold shell giveaways and auctions, and, most importantly, listen to talks by artists and renowned shell experts and researchers. Past speakers and guests included renowned malacologists and authors R. Tucker Abbott and S. Peter Dance, as well as Gary Rosenberg, the Associate Curator and Chair of the Malacology Department of Philadelphia's Academy of Natural Sciences, and the late Harvard zoology professor and invertebrate paleontologist Stephen Jay Gould.
It was our dear friends and fellow shell lovers Owen Gingerich and his wife, Miriam, who invited us to join the "Mal Club." Uncle Owen, as we affectionately call him, is Professor Emeritus of Astronomy and of the History of Science at Harvard and a senior astronomer emeritus at the Smithsonian Astrophysical Observatory. He is also a world-recognized authority on Copernicus and Kepler, and an avid collector of rare astronomical books and manuscripts. Uncle Owen and Aunt Miriam over the years have accumulated an impressive collection of Fusinus seashells.
Top row (from left); Cypraea guttata and Siratus alabaster. Middle row: Charonia tritonis,
Argonauta argo, and Nautilus pompilius. Bottom row: Tibia fusus fusus. The shells, which
are not shown to scale, are from the private collection of Imelda and Edwin.
A Growing Collection
We now have about 2,000 specimens in our shell collection. Most are from the Philippines. The bulk belongs to the Cypraeidae (cowrie) and Conidae (cone) families, though we do have quite a few from the Muricidae (murex), Cassidae (helmet), Strombidae (conch), Ranellidae (triton), Volutidae (volute), Spondylidae (thorny oyster), Harpidae (harp), Nautilidae (nautilus), and other families. (We photographed all the shells shown in this page using a homemade tabletop studio we had set up in our garage.)
It is interesting to note that, like all things in Nature, mollusks are not immune to certain oddities. On rare occasions, we did find a few gastropod shells that are left-handed or sinistral, that is, instead of their whorls growing clockwise (right-handed or dextral), which is the normal way, their direction of growth is counter-clockwise. Other times, we find shells that are unusually large compared to the average size for those species. Some collectors find shells in the wild that are extremely rare or world record in size. A few are lucky enough to discover those from an entirely new species!
These are what make conchology, or the study of shells and the invertebrate animals that inhabit them, such a fascinating and dynamic field. In seeing the diversity of shells, one can’t help but get into malacology, or the study of the mollusks themselves. It is important to understand the behavior of these organisms -- their distribution, evolution, and reproductive cycle -- and how human activities (particularly in terms of pollution, destruction of coral reefs, and overharvesting) are affecting them and their environment.
A live Chambered Nautilus (Nautilus pompilius) photographed in an
aquarium in California. Photo by Edwin Aguirre and Imelda Joson.
For example, mollusks such as the Chambered Nautilus (Nautilus pompilius), which are modern descendants of cephalopods that inhabited the ancient seas millions of years ago, are being harvested by man in such great numbers that if we don’t try to protect their population, they could end up extinct like their prehistoric ancestors.
Malacology and conchology are two fields of the natural sciences where one can see firsthand the urgent need to preserve and conserve the ecological balance. Like all the other living organisms on Earth (including humans), mollusks play a vital role in maintaining that delicate balance. So let us do our part in helping ensure the sustainability of our home planet so that our children and our children’s children would be able to continue to enjoy Nature's bounty and admire these magnificent creatures, not only in textbooks and museums but in their natural habitats as well.
The Allure of Cones and Cowries
Top row (from left): Cypraea mappa, Cypraea aurantium, and Cypraea valentia (juvenile).
Bottom row: Conus miles, Conus betulinus, and Conus litteratus. The shells, which are
not shown to scale, are from the private collection of Imelda and Edwin.
Cones and cowries comprise some of the rarest and most beautiful of all seashells. Their intricate patterns and colors have made them highly prized by countless generations of collectors. The Philippines, an archipelago of more than 7,100 tropical islands in the rich Indo-Pacific region, is a prime haven for these treasures of the sea. Legendary shells, such as the Glory-of-the-Sea Cone (Conus gloriamaris) and the White-Toothed Cowrie (Cypraea leucodon), which once commanded very high prices, can be found in its waters.
The famous "Glory-of-the-Sea Cone," Conus gloriamaris. From the private
collection of Imelda and Edwin.
More than 600 species of cone gastropods (snails) have been catalogued so far throughout the tropics, though some have been found in temperate waters too. Being slow moving, these predators catch their prey (usually worms, small fish, and other mollusks) by injecting them with venom to paralyze them. These neurotoxins are fast acting, and they can even be lethal to unsuspecting humans who happen to handle a live animal. Cone snails such as Conus geographus, Conus tulipa, Conus striatus, Conus textile, Conus aulicus, and Conus marmoreus are among the most poisonous in the world, and therefore should be handled with extreme care.
Dangerous beauty -- some examples of highly poisonous cone shells (from left):
Conus textile, Conus aulicus, and Conus marmoreus. The shells, which are not shown
to scale, are from the private collection of Imelda and Edwin.
Studies are currently underway to find pharmacological uses for the cone snails’ venom in humans. Compounds derived from the neurotoxins have shown promise in relieving pain, and may one day help treat Alzheimer’s disease, Parkinson’s disease, and epilepsy.
To date, more than 200 species of cowries have been identified. They are widely distributed in tropical and subtropical waters of the world, with the greatest diversity occurring in the Indo-Pacific region. Cowries feed mainly on marine vegetation, sponges, and other invertebrates, and their fossil records date back to the Lower Cretaceous Period, some 146 million years ago.
We find the rounded, glossy, porcelain-smooth shells of cowries to be very attractive to look at and very pleasing to touch and caress. In some parts of the world, certain species of cowries have been used in the past as money, and many are still being used extensively in jewelry, charms, board games, handicrafts, and for other ornamental and ceremonial purposes.
We hope this short introduction to the fascinating world of seashells will inspire you to become fellow admirers of these jewels of the sea.