A Queen Conch snail, giving us the eye

Eyes and proboscis of a Queen Conch (Strombus gigas)

by B. N. Sullivan

Conch shells, like all seashells, are created by secretions from the mantle of the snail that lives inside. This happens gradually, over the snail's lifetime.  Most people have seen empty Conch shells, yet few have seen the snails that are the natural inhabitants of those large, heavy shells.  Fewer still realize that those critters have wonderful stalked eyes.

All of the snails in the family Strombidae, to which Conchs belong, have these stalked eyes.  If you come across a live Conch shell while diving, you can see the snail's eyes for yourself if you are patient.  If you pick up the shell and turn it over, the animal inside will retract into the shell almost immediately.  Set the shell down with the glossy aperture exposed and just wait.  Eventually -- say, in five or ten minutes -- the snail will extend its eyes to look around.  If you are lucky, you also may get to see its proboscis (tubular mouth), as in the photo above.

The snail in an upended Conch shell has the ability to right itself, but to do so takes quite a bit of effort on the part of the critter.  So, if you do handle one or set it aperture side up to try and catch a glimpse of the eyes, please do return it to its natural aperture-down position before you leave it.  The photo below shows the snail's eye peeking out of the shell as it moves along the sand in its normal position.

The creature in the photos on this page is a Queen Conch (Strombus gigas), a species common to the Caribbean. I photographed this one during a night dive off the north coast of Cayman Brac.

An eye peeks out as a Queen Conch snail crawls along the sand

Leviathan cowries: Becoming scarce in Hawaii?

by B. N. Sullivan

Here is another favorite from our seashell collection. One of the larger cowries found in Hawaii, its name is apt: Leviathan (Cypraea leviathan).

This one has been in our collection for a long time. I found it in the mid-1980s at Pupukea on the north shore of the island of Oahu. This one is 6.6 cm in length (roughly 2.5 in).

We used to see Leviathan cowries quite regularly, but we haven't seen any at all in quite awhile, alive or empty. These guys live in relatively shallow water, so they are (or were) relatively easy for snorkelers, divers -- and even waders -- to spot. We fear that we're not seeing them these days because too many live ones have been taken by collectors, leaving too few to reproduce and maintain the population.

Older reference books about seashells list Leviathan cowries as endemic to Hawaii. More recently these shells have been recorded in a number of other locations in the Indo-Pacific region, so while we still can say that they are indigenous to Hawaii, they are no longer considered to be Hawaiian endemics.

Leviathan cowries are heavy shells; they definitely are not fragile. And like almost all cowries, they have a wonderful china-like look to them.

One of the distinctive features of the shells of Leviathan cowries is a row of violet teeth bordering each side of the aperture on the underside of the shell. You can see those unusual violet teeth clearly in the second photo on this page. There are several other cowries in Hawaii that have marking similar to the Leviathan, but they are smaller -- and they do not have those wonderful violet teeth!

Another distinctive feature of Leviathan cowries has nothing to do with the shell, but rather with the snail that secretes and inhabits the shell. Readers may recall the photos of a live Tiger cowrie that we posted here on The Right Blue earlier this year. When the creature's mantle was extended over the shell, you could see that it had rubbery-looking thingies sticking out all over it. Those are called papillae. Well, the papillae of Leviathan cowries are quite different. They are spiky clumps that look like little bushes!

The papillae on the mantle of the Leviathan are difficult to describe, and I don't have a photo of a live one to post. Fortunately there is a video on YouTube that shows a live Leviathan with its mantle extended over the shell. You can see the weirdly shaped papillae on the mantle.

Here is makuabob's video, Meet Cypraea leviathan:

If the video does not play or display properly above, click here to view it on YouTube.

Tiger Cowries: The largest cowries in Hawaii

by B. N. Sullivan

Tiger Cowries (Cypraea tigris) have several claims to fame in Hawaii. Two of those claims have to do with their size. The third claim to fame has to do with a traditional use for the shell. (More on that in a bit.)

Tiger Cowries live on tropical reefs in a wide range of places throughout the Indo-Pacific region. They can be found as far west as the Red Sea and the Indian Ocean, and as far south as the tropical shores of Australia. They live as well along the coasts and islands of southeast Asia, and in many locations in the tropical western Pacific. Hawaii is the northeastern-most place on the globe where Tiger Cowries are found.

Tiger Cowries are the largest of the many species of cowries found in Hawaii. Not only that, those in Hawaii grow larger than Tiger Cowries found anywhere else in the world. In Hawaii, Tiger Cowries can grow to nearly 15 cm (about 6 in). Elsewhere, they rarely grow bigger than 10 cm (about 4 in).

Hawaiian Tiger Cowries occur in reef areas at depths from about 4 m to 40 m (about 10 ft to 130 ft). This depth range is another thing that sets them apart from Tiger Cowries found elsewhere. Outside of Hawaii, the species usually is found only in shallow waters, including the inter-tidal zone.

Snorkelers and divers sometimes get to see these shells during the day. Tiger Cowrie shells are very beautiful: they are white or creamy ivory, and covered with irregular dark spots. The spots are mostly brown, but some individuals have a mixture of brown and bluish gray spots. The elaborate pattern of spots on each shell is unique.

The snails usually stay tucked up inside their shells during the day and forage at night, so you have to find one after dark to see evidence of the gray snail that lives inside. At night the animal emerges and crawls along the reef, carrying its shell on its back.

The first photo on this page is a head-on shot of a Tiger Cowrie snail poking out of its shell. If you look closely, you can make out the snail's proboscis and tentacles. It uses these organs to 'sniff' for food and gather it into to its mouth. Tiger Cowrie snails are herbivores -- that is, they eat seaweed and algae.

As the snail moves along to graze at night, it extends its mantle up over the shell. The mantle, with its prickly looking papillae, acts like camouflage when it covers the shell. The snail secretes a mucus that not only facilitates sliding the mantle over the shell, it also keeps the surface of the shell polished and shiny, looking like glazed china or porcelain.

In the second photo on this page, the snail is just beginning to slide its mantle up the side of the shell. In the third photo, the mantle has extended almost completely.

Now, about that third claim to fame. Tiger Cowrie snails are a favorite food of octopus. This was a fact well-known to traditional Hawaiian fishermen, who made lures from Tiger Cowrie shells to attract 'tako' (as octopus is called here in the islands).

Some Hawaii fishermen still use these lures to fish for tako. Writer Jim Rizzuto, well-known in Hawaii for his books and newspaper columns about fishing, discusses these lures and explains how they are made in his book Fishing Hawaii Style, Volume 2 (Honolulu: Hawaii Fishing News, 1987). He notes that the local Tiger Cowrie shell "is easy for the tako to see and is irresistible."

If you would like to try your hand at making a traditional tako lure from a Tiger Cowrie shell, here is a a link to a document from the University of Hawaii at Hilo that tells how to do it: Create a Hawaiian Tako Lure (11-page 'pdf' file).

About the photos: All of the photos on this page are of the same individual. I took these photos during a night dive at Paniau, at the southern end of Puako reef, which is on the western coast of Hawaii's Big Island. Click on any of the photos for a larger view.

Every Seashell Has a Story: The Mole Cowrie

by B. N. Sullivan

Cowrie shells are prized by collectors for their shiny china-like surface, and beautiful colors. Hawaii has many cowrie species. Some are endemic -- found only in Hawaii -- while others are more widely distributed around the Indo-Pacific region. Curiously, though, a number of the cowrie species that are found elsewhere as well as in Hawaii happen to grow to a larger size in Hawaii. One of those is the Mole Cowrie (Cypraea talpa), pictured at left.

Decades ago, on an early dive trip to the Red Sea, I had found a small Mole Cowrie shell and added it to the collection. Back home in Hawaii, we found pieces of broken Mole Cowrie shells with maddening frequency, so we knew they were around, but for the longest time we never could find a whole Mole Cowrie -- dead or alive.

One day, finally, we saw a large Mole Cowrie shell, all by itself on the surface of the sand. We hurried toward it, anxious to pick it up and examine it to see if it was alive. But before we reached it, a Spotted Eagle Ray appeared out of nowhere, swooped down, and snatched the Mole Cowrie from the sand. The ray quickly swam off, still munching its snack, and expelling sand and broken pieces of shell through its gill slits! Of all the nerve!

This time our disappointment was short lived. Just a few weeks later we were heading back to the reef after another deep dive out on the sand flat at Puako. We began to gradually ascend as we swam shoreward. As we passed over a large boulder that we used as a landmark on our route, I was amazed to see beside it a large, whole Mole Cowrie shell. Since we had begun our ascent, we were already a good 5 meters above the rock, but I couldn't resist dropping back down to check out the Mole Cowrie.

Since I had my camera in hand, the first thing I did was take a photo of the Mole Cowrie where it sat on the sand, without distrubing it. That's it in the photo on this page. A nasty looking Viper Moray eel that was hiding in a crevice near the base of the big rock poked its head out as I snapped the photo of the cowrie shell. The eel -- mouth open, eyes glaring -- looked right at me as I reached for the shell. I wondered if the eel would grab the shell, just as the Eagle Ray had done weeks before. But no, the eel tucked itself back into its crevice, so I picked up the shell. As I picked it up, I could tell that it was very light: it was empty!

I looked up at Jerry who was still hovering 5 meters above where I knelt and gave him the 'okay' sign. I popped the shell into my trusty little mesh bag and we swam back to shore with our new treasure.

Like most cowries, the Mole Cowrie forages at night. When the snail is active, it slides its fleshy mantle up over the outside of the shell until it is completely covered. The secretions from the mantle are what keep the surface of the shell so smooth and shiny. Here is a link to a photo of a live Mole Cowrie with the mantle extended, so you can see what it looks like.

Every Seashell Has a Story: Hawaiian Stromb, a Very Rare Find

by B. N. Sullivan

Over the years we have become quite adept at finding shells underwater, but some species that we wanted for our collection were elusive for a long time. There were some we had seen in books or displays that we just never came across in the ocean. In other cases we had found the shell, sometimes on numerous occasions, but only ones that still had the critter living inside.

As I mentioned in an earlier post about shell collecting and diving, we do not take live shells that we find in the ocean, so we are especially delighted when we come across an uncommon or particularly beautiful shell that also happens to be empty.  In the previous post, we told the story of finding an Arabian Cowrie in the Red Sea.  In this post and the next, we'll tell the stories of a few more very special seashell finds.

The shell on this page is a Hawaiian Stromb (Strombus vomer hawaiensis),  a very rare Stromb subspecies endemic to Hawaii.   [Click on the photos for a larger view.]  Not only does it exist only in Hawaiian waters, the Hawaiian Stromb only dwells at depths below 25 meters (more than 80 ft), so the likelihood of finding it on a beach is nil, and snorkelers will never get to see it in the water, either.

The find was quite accidental: we weren't even looking for shells at the time.  We were doing a deep dive -- on a mission to photograph some cerianthid tube anemones that lived on a sand flat at Puako at a depth of about 40 meters (around 130 ft) and below.  Not wanting to rack up any more decompression time than we had planned and prepared for, we had descended quickly to the sand flat, and we were hustling to the spot where we knew the anemones lived.

The surface of that particular sand flat is relatively barren terrain, with very few rocks or other features -- just hard-packed sand and mud, gently sloping into the deep for as far as the eye can see.  For that reason, things that stick up out of the sand -- even small things like the cerianthids we were there to photograph -- are relatively easy to spot.  In this instance, what Jerry spotted as he swam along was the pointy tip of the Hawaiian Stromb shell protruding from  the sand.

As Jerry tells it, he recognized immediately that it was a piece of shell, but he figured it probably was a broken shell.  He dug it up, curious to see what kind of shell it might be, way out there in the middle of nowhere.  I watched him uncover what turned out to be a whole shell, not a fragment.  

When Jerry picked it up and brushed the sand away with his glove, I heard him shriek and saw his eyes widen behind the faceplate of his dive mask.  He held out the shell to me, and it was my turn to shriek when I realized what species it was.  The aperature of the shell was packed with sand, indicating that there was no animal inside.  What an exciting find!

This Hawaiian Stromb was a bit crusty from having been buried in the sand for who knows how long, but it cleaned up very nicely.  Our specimen is 7 cm (2.8 in) long.  It has become one of the greatest treasures in our seashell collection.

More seashell stories to come, after Wordless/Watery Wednesday...

Every Seashell Has a Story: The Arabian Cowrie

by B. N. Sullivan

Here's a special cowrie shell from our collection. The shell pictured at right is an Arabian Cowrie (Cypraea arabica). Jerry found this one in the Red Sea many years ago, and it is the only one we've ever seen, except in pictures.

I had to tell about this one today, since I'm writing this on Easter.  As it happened, we had gone on a dive trip to the Red Sea over the Spring holidays one year, and Jerry found this shell on Easter Sunday. We always joked that the Easter Bunny must have put this egg-shaped cowrie shell there for him to find that morning.

As cowrie shells go, this is a fairly large species.  The Arabian Cowrie shell pictured here is 6.5 cm (about 2.5 in) long.

The first photo shows a dorsal view of the shell.  Below are two more views of the same shell, so you can see its interesting markings.  First is a side view:

And here is what the base of the shell looks like:

Here is a link to a photo of a live Arabian Cowrie on Wikipedia. You can see the pale colored mantle of the snail that manufactures the shell and lives inside.  There was no snail inside the Arabian Cowrie shell that Jerry found.

Conus striatus - A fish-eating cone shell

by B. N. Sullivan

In a recent post, we introduced our readers to Cone Shells, and the snails that make those shells and live in them.  We mentioned that the Cone Shell snails  have a venomous sting, making them potentially dangerous to handle when they are alive.  

Unlike some other mollusks, which eat algae, the animals that inhabit Cone Shells are carnivorous , and they use their venom, which is a neurotoxin, to immobilize or kill their prey.  Some Cone Shell snails eat other mollusks, while others eat marine worms.  A few Cone Shell species, like the one on this page, actually eat fish!

This is the Striated Cone (Conus striatus), a relatively large Cone Shell species.  The one pictured here is from our shell collection.  We found it in a sandy patch at a depth of about 6 meters (20 ft) off the coast of Puako, Hawaii.  It is  10.4 cm in length (about 4.25 in).  The Striated Cone is uncommon -- that is, it is not abundant in most locations.  At the same time, though, it is widely distributed.  It can be found in many different locations around the Indo-Pacific region, from the Red Sea all the way to Hawaii.

The Striated Cone is one of the Cone Shell species considered to be potentially dangerous to humans.  For one thing, its venom is among the most potent.  For another, the snail is amazingly flexible and agile.  Its siphon and proboscis (where the stinging radula teeth are located)  can be extended nearly the length of its shell.  Thus, even if you are careful to hold a live Striated Cone Shell by the widest end, it still may be possible for it to sting you.

The Striated Cone snail hunts primarily at night.  A wily predator, its method is to sneak up on a  small fish that is 'sleeping' on the bottom and sting it, injecting it with venom.  The neurotoxic venom paralyzes the little fishy.  Once the prey is thus immobilized, the snail literally engulfs it.

You might imagine that it would take quite awhile for a snail to engulf a fish.  In fact, the snail's proboscis (mouth) expands and it hoovers in the prey in a remarkably short time, swallowing it whole.

Don't believe me?  Have a look at this video of  Striated Cone Shell snail attacking and consuming a little fish: .

If the video does not play or display properly above, click here to view it on YouTube.

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NOTE: This post was included in the Carnival of the Blue 23 over at Deep Sea News. (Thanks, Kevin.) We invite all of our readers to drop by the Carnival for more wonderful articles about the sea and its fascinating inhabitants.

Hawaiian Spindle Shell

What: A Hawaiian Spindle (Fusinus sandvicensis) from our shell collection.

The shell is 15.6 cm long (about 6.25 in).

Where: I found this shell while diving near Puako, Hawaii

at a depth of about 115 feet (35 m).

Click on the photos to enlarge.

Leopard Cone - The largest cone shell in Hawaii

by B. N. Sullivan

We promised to show our readers some of the shells we have collected over our many years of diving.  All of the shells in our collection were found by us; none were purchased.  Some of the shells in our collection were found while beachcombing, but most were found underwater.

The Leopard Cone (Conus leopardus), pictured on this page, is the largest Cone Shell in our collection.   In fact, the Leopard Cone happens to be the largest Cone Shell species found in Hawaii.  According to E. Alison Kay's authoritative book, Hawaiian Marine Shells*, Leopard Cones grow to a length of about 140 mm (5 in), and a diameter of 80 mm (about 3.5 in).  Our specimen is 105 mm (about 4.25 in) in length, with a diameter of 60 mm (2.75 in) at the widest part.

The specimen pictured on this page is a little battered, but it is the only one we ever have found that was not alive, and also not broken.  We found it about 25 years ago while diving on the north shore of the island of O'ahu, in an area known as Pupukea.  The Leopard Cone is fairly common in Hawaiian waters, but it also can be found elsewhere in the western and south Pacific [Click on the photos for an enlarged view.]

Kay describes the Leopard Cone shell as "cream white with many (18 or more) spiral rows of blue-brown to black spots, which are often more pronounced in smaller individuals."  Like many shells, live Leopard Cones are covered with a thin coating called periostracum.  The periostracum is somewhat sticky, so it's not unusual to see one of these guys on the sand with algae and sand grains stuck all over it.  

The Leopard Cone snail is light tan or yellowish, mottled with brown.  This species eats marine worms.

Last week I posted an article about collecting Cone Shells, and the care that is required when handling them.  Live ones can be dangerous, because the snail inside is venomous and its sting can cause pain, paralysis, and even death.  If you are interested in collecting shells while diving or at the beach, you may want to have a look at that article.

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* If you are interested in identifying and learning about marine shells from Hawaii, there probably is no source more comprehensive than E. Alison Kay's Hawaiian Marine Shells:  Reef and Shore Fauna of Hawaii, Section 4: Mollusca (Honolulu: Bishop Museum Press, 1979). Of course, since it was published thirty years ago, it does not include marine mollusks discovered and identified since then. Still, it is a remarkable piece of scholarship that has enduring value. I believe the book is now out of print, but it still is available in libraries and some second-hand bookstores -- and on my bookshelf!

Dr. Kay, who passed away last June, probably knew more about marine mollusks in the Pacific than anyone on the planet. Originally from Kauai, Dr. Kay earned an M.A. at Cambridge University as a Fulbright scholar before returning to the University of Hawaii for her Ph.D. Her 1957 doctoral dissertation was on cowrie shells, and years later, a cowrie shell was named after her (Cypraea alisonae). She had a long career as a Professor at the University of Hawaii, and also worked with the Bishop Museum in Honolulu.

Collecting Cone Shells: Special Handling Required

by B. N. Sullivan

In the last several posts we have been talking about collecting sea shells, and how divers can find shells underwater.

We strongly discourage the taking of live shells from their habitat. Taking live shells depletes populations by preventing the creatures living inside from reproducing. It also can disrupt the ecological balance of the habitat, since these creatures have roles as both predators and prey.

Previously, we offered a few tips on how to figure out if there are creatures living inside a shell. Today we would like to add a word of caution, particularly in regard to Cone Shells (Conidae).

There are hundreds of species of Cone Shells. The shells are attractive, and popular with collectors, but you should know that the snails that build and inhabit Cone Shells are venomous. Handling a live Cone Shell can result in being stung.

The Cone Shell snails are carnivores: some prey on other mollusks, others eat worms, and still others actually prey on fish! The snails have a structure that works a bit like a hypodermic syringe. They produce a venom that contains neurotoxins. They inject the venom into their prey through hollow stingers. (Technically, the 'stingers' are tiny, harpoon-like radula teeth.) Depending on the species, the venom either kills or immobilizes the prey.

There have been numerous cases documenting Cone Shell envenomation in humans. Depending, again, on the Cone Shell species, and also on the site of the sting, the result can range from pain, to paralysis, to death! So, if you see a Cone Shell in the water, understand that it is a venomous creature, and approach it accordingly.

If you are going to handle a Cone Shell to see if it is alive, pick it up carefully by the crown -- that is, the broad end of the cone. The stinging part is in the proboscis, which is at the 'nose' of the cone. Better yet, use something inanimate as a tool to flip over the shell so that its aperture faces upward. You may immediately see some part of the snail, but even if you don't, you should wait for awhile to see if the animal appears and tries to right itself.

If you find shells -- including Cone Shells -- while diving, it's convenient to carry them in a small mesh bag that you can clip to a D-ring on the outside of your vest. In any event, do NOT put a cone shell into your pocket or carry it in your hand, even if you think it is empty -- just in case!

We recommend that divers (and others) who are interested in collecting shells learn something about the creatures that formed the shells and live inside them. An understanding of how and where they live, what they eat -- and what eats them -- not only facilitates knowing where to look for them, it also provides the collector with a better appreciation of how the creature fits into the ecosystem. Today we add another item to this list of reasons to learn something about these creatures: your own self-protection.

About the photos: I took these macro photos of a live Mediterranean Cone Shell (Conus mediterraneus) on a sand flat off the coast of Dhekelia, Cyprus. As far as I know, this is the only Cone Shell species native to the Mediterranean Sea. The shell is relatively small -- about 3 cm (1.25 in). By the way, despite its appearance, that brownish structure sticking out near the wide end of the shell in the second photo is not the 'stinger'. It is the snail's operculum - a sort of lid that the snail uses to close over the shell aperture for protection when it retracts into the shell. The operculum is hard, made of material similar to our fingernails.

Curiously, we have never found an empty Mediterranean Cone Shell, so we have no examples of this shell in our collection. Fortunately, we do have several nice photos of the living species. Some long-time readers of The Right Blue may recall another post featuring this species, from 2007: Muck diving - The tale of the cross-eyed cone shell

Queen Conch - What strange eyes you have!

What: Queen Conch (Strombus gigas).

Click here to learn about the Queen Conch.

Where: I took these photos of the Queen Conch's eyes at Radar Reef,

on the north shore of Cayman Brac.

Click on the photos to enlarge.

Finding Shells Underwater

by B. N. Sullivan

I have been collecting seashells since I was a little girl. Early on, my collecting was limited to shells I found washed up on a beach somewhere, but once I learned to dive, I began looking for shells underwater. Later, when Jerry and I began to dive together, he took up the hobby, too, and over the years, we have amassed quite a respectable shell collection.

We are purists about shell collecting. As I mentioned in the previous post about shell collecting and diving, we do not buy shells, and we do not sell them, or even trade them with other collectors. All of the shells in our collection have been found by one of us.

We also are purists in another sense: we do not take 'live' shells -- that is, shells still occupied by anything living, whether it is the snail that originally secreted the shell, or a hermit crab that has adopted the shell as a home. I cannot say that we never have been tempted to take a live shell; of course we have been. But we don't do it because, over the decades that we have spent in the ocean as divers, we have witnessed a noticeable decline in the number of shells that we see. We know that one of the reasons is that collectors -- and dealers catering to collectors -- have repeatedly harvested live shells before the critters that live in them have had a chance to reproduce.

Many popular dive areas around the world officially prohibit the taking of shells, live or otherwise. There was a time when this kind of rule was encountered only in officially protected areas, such as marine parks or preserves. Nowadays, many dive operators and resorts (and even some municipalities) prohibit divers from collecting any shells, including empties. These 'no-take' rules may seem extreme to some, but in many cases they have arisen because divers (and other people) were taking shells indiscriminately, including those still occupied by their natural residents, and populations were becoming seriously depleted. If you dive in an area that prohibits shell collecting, do follow those rules.

Shell collectors should be conservation-minded, even in areas where collecting is not officially prohibited. We have witnessed plenty of instances of egregious over-collecting. For example, one time we saw a diver climb aboard a boat, carrying twenty-some Marlinspike Augurs (like the shells in the photos on this page). He proudly announced that he had spent his whole dive digging in the sand for them. All of them were alive. Another time, a diver waded ashore with a very large glob of mucus oozing out of the pocket of his BC vest. It turned out that he had collected several large, live cowries and had stowed them in the pocket. In both of those cases, other divers in the party confronted the poachers. The man with the Marlinspike Augurs tossed all but three overboard; the man with the cowries kept his shells, casually announcing to us that "the animals are probably dead by now anyway."

Divers are not the only ones who sometimes engage in excessive collecting. Early one morning as we were preparing to enter the water for a shore dive, we saw a woman sitting near the edge of the water beside a plastic bucket. As we walked past, we were horrified to see that the bucket was half full of assorted cowries. We asked what she was planning to do with all those cowries. She told us she was waiting for the sun to kill them so she could "scrape the muck out of them" with a penknife. She said she had collected them the evening before, while wading in the shallows. It turned out she was a tourist, staying at nearby vacation rental cottage. She told us she did this every year when she visited Hawaii, because she liked to take the shells home to her friends as souvenirs.

As collectors ourselves, we obviously have no quarrel with taking shells, but we do promote prudence in collecting. Don't take live shells; and learn to be satisfied with collecting one or two examples of a given species. If you find a handsome shell that is occupied, do photograph it, but please don't deprive the poor little guy inside of its home.

How to Find Shells

Our success as collectors has grown from an understanding of which critters live where. If you want to collect shells, the first thing you need to do is learn something about the mollusks that create the shells. Learn which kinds live where -- in sand, in rocky rubble, among coral -- then you will know where to look for them. It also helps to learn what they eat. You won't find them where there is no supply of their preferred food.

Learn which other animals eat the snails that inhabit shells. If you discover where a mantis shrimp lives, for example, you may find a small cache of empty shells near the entrance to its burrow (although many will be broken). If you notice an octopus hunting, follow it for awhile and you might be rewarded. We once acquired a large tiger cowrie shell, compliments of an octopus. We watched as the octopus enveloped the tiger cowrie with its body, sucked out the poor snail, and then dropped the empty shell onto the sand. We still have that shell, thank you very much.

Another strategy is to take note of places where empty shells tend to collect naturally, due to the forces of waves, surge, and currents. In reef areas, small conglomerations of shells often can be found near the base of large rocks or coral heads. In inter-tidal zones, waves and surge will carry empty shells along and deposit them among the rocks. Sometimes shells are buried under a bit of sand, so a good technique to use in a likely area is to wave your hand to fan away the top layer of sand to expose the shells.

When you find a shell, how do you know for sure if it has a creature inside? Sometimes it's very easy to see if a shell is empty. If you pick it up and a lot of sand pours out of it, usually that means it is unoccupied.

If you find a shell with its opening facing upward, it probably is not alive, since mollusks and hermit crabs that live inside shells typically move along with the shell on top of them. But the aperture-up rule is not foolproof. Finding out if there's anybody home inside mostly takes patience. You need to leave the shell, aperture up, undisturbed for awhile -- sometimes for as long as 10 or 15 minutes. Wait, and eventually an animal living inside -- whether a snail or a crab -- will poke out, or even try to right itself. The second photo on this page shows that the Marlinspike Augur, which looked to be empty at first, actually had a tiny hermit crab living inside.

Coming up: more stories about certain types of shells and the creatures that live in them.

Shell Collecting and Diving

by B. N. Sullivan

Awhile back, a repairman came to our home.  As he passed through our house on his way to the offending appliance he was there to fix, he screeched to a halt beside a display case in our dining room.  Inside the display case were several hundred small seashells.

He told us he was an avid shell collector and asked if we would mind if he took a moment to look over our collection.  We told him to go right ahead.

He stood there for awhile, quietly reciting the names of the different shell species as his eyes passed over the rows in the display.  It was obvious that he knew something about shells.  At length, he looked up at us and declared, "This is a really beautiful collection!  You must have spent a fortune for these."

Jerry and I exchanged puzzled looks, and then one of us told him we had paid nothing for the shells.  We had found all of them.

The repairman's eyebrows raised in surprise.  He said, "You must be divers -- and you must do a lot of deep dives."

We acknowledged that this was so, but then asked how he knew that.  He said, "You have a lot of shells that are never found on the beach, and a lot of those only live in deep water.  If you didn't buy them, then you must do a lot of deep diving to have so many different deep water species."

Then he looked at the display case again and commented, "Funny, though.  I don't see any cowries. Most divers who collect shells have at least some cowries..."

The cowries were in the next room, we told him,  in a separate display case.  We led him there to see our cowrie collection.  His gaze zeroed in like a laser on a small cowrie in the middle of a row in the display.  He pointed to it and gasped, "You actually found this one?!"

We told him where we had found it, and he shook his head in amazement.  We took the shell out of the display case so that the repairman could have a better look.  As he turned it over in the palm of his hand,  he said he had been trying to acquire an example of that shell species for years.  Several times, he told us, he had seen one for sale at auctions, but he never could afford them.  He said they always sold for more than five hundred dollars.  

Now it was our turn to be amazed!  We never buy shells, nor do we sell them, so we never had thought of  our shells in terms of monetary value -- and the one that was supposedly worth so much wasn't even among the prettiest of our shells!  We do  have lots of very pretty shells, but the most cherished shells in our collection are those  that have a personal story attached to them. 

In the next post, we will give our readers some pointers about how to find shells while diving, and then we will tell about -- and show --  some of our favorite shells.  Stay tuned.

About the Photo: That's our friend Dan, looking for shells among the rocks in a surge area along the coast of Puako, Hawaii.

Wordless Wednesday #23 - Marlinspike Auger

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