Collecting Seashells: Types of Shells

I live near the East coast of Florida and go boating and fishing on the Indian River and Mosquito Lagoon area often.  Out on the river and in the backwaters is where I find the best seashells.  Often they are occupied by hermit crabs, or by the sea snail that made the shell.  But they are fun to photograph.

It can be confusing as to what is a whelk shell, and what is a conch (pronounced "Konk").  In general, a conch shell is large and heavy.  It's thicker than whelks, which are lighter, yet can still be quite large.

These are the four larger whelks you may come across in certain areas of Florida.  

The shell my son is holding is a big Lightning Whelk.  They open on the left side, which is unique for gastropods, and can grow to be over a foot in length - up to 16 inches.  When I took that photo I had no idea what type of shell he was holding, but the left side opening gives it away.

Recently, while boating, I found a partial Channeled Whelk, and I've found cute Pear Whelks but all were inhabited by hermit crabs.

The channeled whelk can be around 8 inches in length, and the pear whelk is smaller, coming in at 5.5 max, according to my Florida's Living Beaches book.  (I've linked to it further down on this page.)

All the shells you see dotting the beach were made by the creature who lives (or lived) inside.  The mollusk is a marine snail and it's life becomes a work of art in the form of it's shell. 

Mollusks can create a shell that is either all in one piece, or in two sections that are hinged together.  The snails that create one, coiled shell are called gastropods, or sometimes "univalves", while the bivalves are the ones with two separate shell parts, like clam shells.

Generally, the difference in the shells depends upon  the lifestyle of each.  Gastropods crawl along the ocean bottom or among coral using a strong "foot" in search of food, while the bivalves attach themselves to something and are stationary, grabbing food as it flows past.  My picture here of the King's Crown conch is an example of a gastropod, while clams, oysters and scallops, like the Kittenpaw shell is a bivalve.

All seashell photography on this page is my own, unless otherwise stated.  My pictures are NOT free for use by others for any reason.

I have a few good shell collecting and identifying books.  The "Florida's Living Beaches" book listed  above (the 2nd edition is shown, I have the first), by authors Blair and Dawn Witherington, is a comprehensive guide to the beaches of Florida.  

Each separate area of the book takes a close look at an aspect of seashore ecology.  It has a section with pictures of shells that are commonly found along the expansive coastline.  You will also discover the best areas of the state to find the more rare types of shells.  Any nature lover will enjoy this book.

The book includes lots more information about how beaches are created, and the ocean water that contributes to coastal habitats.  It covers dune plants, land mammals, birds, fishes, tides, and more.   Each page is packed with photos, and the writers include fun tidbits of information in the "Did You Know?" sections.

Bivalve shells are simply shells that were formed in two parts, such as the cockle shell, clam, scallop and oyster.  Each of these types of shell includes many varieties that come in many colors and sizes.

Usually you will find one part of the shell washed up on the beach as it has broken apart while being rolled in the surf. For this reason, finding both sides of a bivalve attached, is rare.

On the east coast of Florida the ark shells (pictured here) is widely found and it can be white, tan, gray, brown or any combination.

Other bivalves that are sometimes found on Florida beaches are the pen shells, angel wing, Turkey wing, cockles, scallops, telling, clams, and jewel box.

Oysters grow in shallow water and along the shores of islands in the Intracoastal Waterway.  Oyster beds filter the water and are good for the environment, but are a hazard to boaters. The shells are sharp and can damage the hull, and cut feet.

Seashells are rare if they are not often found... no kidding ...you say?  Well, that one is obvious.  But rare shells are also the ones that have been created differently than the norm.  

For instance, a knobbed whelk shell is ordinarily right-handed, with it's opening on the right.  But if a knobbed whelk mollusk gets confused, and makes it's shell backwards, then it's a rare shell.  It's a left-handed knobbed whelk, of which there are not many.

Of course in order to know which shell is not made like all the others, you need to know what the normal shell looks like.  That is why I write about shells.  I am learning along with my readers.  Believe me, I am no shell expert.  

But if you want to know what the shell experts know (the conchologists) and the big time shell collectors, you may be interested in buying the type of book they use.  I will warn you, some of them are expensive!

Unless you plan to travel to far away beaches, buy a book that identifies shells found in the area you frequent.

The more I get out on my boat and visit the backwater areas of the Indian River, the more hermit crabs I see.

I'm always on the lookout for seashells.  I enjoy collecting them, if I find something unique, but it must be empty too.  The mollusk must be gone, which is usually how you find shells washed up on the shore.  But in the case of empty shells out in the water, another type of sea life is happy to grab up that empty shell.

Hermit crabs must always carry a shell as protection.  For that reason hermit crabs in the wild will constantly be on the lookout for empty shells to call home.  As the crab outgrows his shell, he will need another bigger one.  Sometimes hermit crabs line up waiting to grab that special home.  They will fight over it!  Check out my blog post with a video of the giant horse conch eating a snail, and crabs moving in to collect that empty shell.

I find loads of seashells of all kinds on my boating trips to the shallow backwaters, but they are almost always inhabited by some sort of hermit crab.

These are the cowry, or sometimes spelled cowrie, shells. I purchased them and didn't find them on the beach. Both are quite large, with the Atlantic Deer cowry (on the left in the photo) is about four inches long.

This type of shell is coveted by collectors for it's shiny porcelain appearance.  I remember when I bought it that I wondered if it was a real shell because it seemed like it was made of glass.

Some of the cowry shells were used as currency all over the world, many years ago. They are called money cowry - appropriately enough.  In fact, I have read that in some places the shell is still used as such.

Smaller versions of this shell are often used to make jewelry, and often times people will own a cowry necklace.

Florida has many miles of beaches, but for the serious shell collector, the Gulf coastline is the best  place to do some beach-combing.

The beaches of Sanibel Island are known as one of the best places in the world for shell collecting - coming in at #3 - for it's shell abundance and variety.  It's the place where you could find a Junonia (pictured) which would be a treat, as finding one in great condition is rare.

Florida gastropods you may find on both the East and West (Gulf) sides of the state include the following:

• Slippersnail or Slipper shells (1-2 inches)
• Shark's Eye (max 3 inches)
• Fighting Conch (max 4 inches)
• Worm Snail (length varies)
• Cerith (about 1 inch)
• Scotch Bonnet (max 4 inches)
• Nutmeg (less than 2 inches)
• Tulips (can be 4-5 inches)
• Whelk shells (Lighting - see below, Pear and Knobbed)
• Lettered Olive shells 

The large and small shells pictured in the photos below are shells I've had for years.   Although I recognized the big one as a lighting whelk, the identity of the small one eluded me.

As I was going through my seashell collection one day, I looked more closely at the little one and it dawned on me!  It was a juvenile lighting whelk!  I guess an expert would have known right away, but besides the fact that it is shaped the same, and the coloring of dark lines over white is similar, it's opening is on the left side!

Lightning whelks are sinistral, or left-handed shells, meaning that when you hold them by the tip, or bottom, the aperture will be on the left as opposed to the right (dextral) like most gastropods. 

My photo here shows the lighting whelk (right) with the strawberry conch.  If you happen to find a lighting whelk with the opening on the right, you've found a rare shell!

Be aware that some shells, like the pear whelk, look a lot like a lightning whelk, and they open on the right.

The colors of shells are determined by their species and heredity mostly, but also by what the mollusk (animal inside) eats.

They have a fleshy mantle, or "cape", that may either partially, or totally, cover the outside of the shell and it secretes a calcium solution which grows the shell larger while creating the colorful patterns and ridges.  (The Flamingo Tongue shell is totally covered by a pretty, spotted mantle which is not part of it's shell.)

The mantle also polishes the part of the shell it touches and that is why some shells are very shiny. The coloring can also add hardness and be a camouflage to predators.  A good example of the use of shell camouflage, called countershading, is the Chambered Nautilus.

The shape and type of shell produced will have to do with how and where the animal lives and hunts for food. If the shell has spines, like the murex, it may be to discourage predators, and if it's long and coiled, like the olive shell, it is useful for burrowing through sand.

Sealife is amazing and diverse.

Every shell is unique and beautiful in it's own way and if you can get past the "bigger (shell) is better" mentality, you will discover some wonderful shells right under your feet.  In Florida the coquina clams are abundant and can make a colorful collection.  Conquinas can be just about any color and they live right along the wave line.  In fact when you see shore birds feeding in that area, they are probably eating coquinas.  Since they are so abundant, finding empty coquina shells are easy.  In fact I don't have many in my collection because they were so common to see on the Florida coast, I just did not collect them.

Other commonly found (in certain areas) small bivalves include jingle shells, kitten's paw, oyster and scallop shells.  (The purple and pink splotched shells in this photo are calico scallops).

LIttle gastropods (coiled shells in one piece) can be a great find with bumps and swirls of color, such as the Common nutmeg, moon snail and cowrie.  And remember that the large shells will begin as juveniles and sometimes tiny versions of a magnificent shell can be found.

Small empty (dead) seashells can be collected and used for crafts or decorating so don't overlook the little shells.

(Photo of tropical shells by P. Carter)

Ask anyone what they would love to find while visiting the ocean and they will probably say a starfish or a sand dollar.

Sea stars (commonly called starfish) and sand dollars are not really shells.  They are echinoderms and if you find a dead one, you are seeing the exoskeleton of the once living animal. 

Sand dollars live on the sandy ocean floor and sea stars are also ocean dwelling, either moving over the bottom or clinging to coral and sea fans.  

They don't come up on shore unless they have been washed up by a storm.   Living ones will not look like the one in this photo.  If you find a white sand dollar on the beach, it has died and been bleached white by the sun.

The sea urchin also belongs to this group, and all of these treasures will be more fragile than seashells and will break easily.

Seashells will be empty if they are "dead" and okay to collect.  If there is something protruding from the opening, or you see a hard cover over the opening, that means it is still occupied.  Starfish and sand dollars will be bleached white or whitish by the sun and will be brittle.  Anything washed up on shore is probably dead.

If you come across something living, take a photo - don't take the shell!   

This horse conch I found was empty, but there were living things (those big bumps, which I think are coral) attached to the outside.  So I took some pictures and put it back in the water.

A tropical beach vacation is something many people plan all winter long so don't let your lack of knowledge get you into trouble. 

In many areas taking live seashells from their habitat is illegal.  Also disturbing dunes and especially turtle nests (pictured) can get you into trouble.  Be aware of the rules and laws wherever you visit or vacation and don't disturb or collect wildlife.

If you do take living sand dollars or seashells, you will be sorry when the animal dies and begins to stink.

Swim where lifeguards are present, and check the conditions as there can often be riptides or strong undertow conditions.  Sometimes jellyfish are dead on the beach, which means there could be some in the water too.

Also be aware that hurricane season in Florida runs from June 1st through November 30th with August and September being the two most active months.  You can't help it if a hurricane forms while you are on vacation, but knowing about evacuation proceedures and what to expect ahead of time is a good idea.

(Photo: Sea turtle nest marker.  Credit:Morguefile)