This is a picture of my spiny jewelbox seashells. I don’t have many and they are simply call Spiny Jewelbox (Arcinella cornuta). They are white with spikes or ridges (if the spikes have worn down) and the inside is pinkish. These are found on both Florida coasts, but mainly along the Gulf Coast area. Many may not have spines as they are broken and worn by the sea. Continue reading The Jewelbox Seashells Are Leafy, Spiny and Corrugated
Sometimes a shell, living in the wild, will look very different than when it’s washed up empty on the beach. In the case of the Flamingo Tongue (Cyphoma gibbosum) snail, the coloring belongs to the animal while it’s alive. The mantle, or fleshy, cape-like covering, is what you are looking at in this picture, and it contains the pretty roundish spots that are yellow-orange, outlined in a darker color.
It is not a large shell, measuring at most about 1.5 inches and you will probably only see one living if you are snorkeling or swimming since they live on sea fans and feed off of coral in shallow ocean water.
Although this looks like a beautiful shell to add to your collection, the shell itself, which is hidden from view by the mantle, is mostly white with a bit of a yellowish tint. The outstanding characteristic of the shell is the ridge that you can see crossing the center of the shell.
Don’t be fooled into thinking you have found an amazing spotted seashell, if you see this little guy. Collecting it will kill the animal and the shell will not have spots. You will both lose.
In my Florida life, a seashell was a seashell. Some were prettier than others, some were larger and I just called them shells and never knew they were actually mollusks. In fact, when I found a nice shell, I never gave much thought to what had once lived inside.
Now I have learned to speak seashell. At least to the degree that I know the difference between a gastropod and a bivalve and that animals in the phylum mollusca inhabit most every area of the earth, although I write about the marine mollusks, the ocean-dwelling ones. (In England mollusk is spelled “mollusc”.)
Mollusks are invertebrate animals and I am mostly interested in the ones that live inside their shell homes, but some mollusks don’t have shells (squid, cuttlefish and octopus). They consist of single shells that are all in one piece – gastropods or univalves, and shells that are hinged, or two pieces – bivalves. They all live in ocean water or brackish water, which is less salty as it is combined with fresh water.
I mainly use the common names of the shells when describing them, but the scientific names are important and each shell will have two parts to it’s name and it is always italicized with the first part being capitalized and the second is not. I don’t know why, and forgive me if I sometimes don’t include the scientific name, but searching for information about a certain shell is easier when using it. That is when you will come across the more scientific sites – which this blog is not.
When reading the descriptions of a gastropod on a more scientific site, you will read about the spire (top part of the shell), whorl (the way it twists), aperture (opening), lips (edges of the opening), canal, and operculum which seals the “door” when the animal retreats inside it’s shell. The bivalve descriptions could include describing the umbones, ligament and hinge teeth. Most descriptions will include colors and characteristics unique to that shell and the inside color along with the size and where it can be found.
It is difficult to find a lot of information and good photos online, and if you really want to study seashells, I suggest buying a book about shells in the area you plan to be beachcombing.
I have collected some shells and pieces of shells that are full of holes or have crazy lines etched in the top. Sometime a shell will have a perfect hole all the way through it, just as if it was meant to be hung on a wire to make a pretty necklace. I never knew what caused these phenomenons until I read about “Shell Wars” in my new reference book, “Florida’s Living Beaches, A Guide For the Curious Beachcomber” by Blair and Don Witherington. In the mollusk section of the book they explain how some gastropods will bore holes through the shells of others to feed on them. In doing so, they leave a hole, or sometimes lots of holes as in the case of boring sponges that use acid to digest shells and actually leave them looking like a sponge – full of holes.
You can see in my picture on the left that one of the cockle shells has a hole at the top and in the photo on the right there are plenty of examples of shells that have been changed into porous looking shapes and no longer resemble seashells.
When you find a beautiful shell on the beach, do you ever think about the creature that used to live inside? If you are like me, probably not. At least, I never did until I began to study seashells. I will never look at shell collecting the same way now that I can imagine the snail like animal moving about the ocean floor carrying his shell along, searching for food. Sometimes that food is another mollusk.
The frog shell is not extremely pretty as it tends to be covered in “limy deposits”. The St. Thomas Frog Shell (Bursa thomae) got it’s name because it was first discovered in St. Thomas in the Virgin Islands. It’s a small shell, growing only to a little over an inch long.
Another frog shell – the California Frog Shell (Bursa californica) is commonly found in Baja California where it is frequently pulled up in crab and lobster traps. This species is larger and can be up to 5 inches in length.
Info taken from National Audubon Society’s Field Guide to Shells
See another photo of a frog shell – The Yellow Mouthed – here.
I am not in love with science. I call my shells by their common names and pay little attention to the Latin names and don’t really care which “family” they belong to, but I realize that some people might.
So this is my attempt to explain the classification of seashells, beginning with the “Class”.
The variety of sea shells is amazingly huge. I can’t imagine having to organize shells into groups and since the same types can look very different depending on their colors, size and age, but each type has been assigned a “class”.
The class is fairly simple to figure out since each has it’s obvious differences.
Gastropods : Snail type shells that curl around and are all in one piece (univalves).
Bivalves: Shells that come in two parts, such as a clams and oysters.
Cephalopods: Mollusks without shells (mostly – the nautilus is a cephalopod), such as the squid and octopus.
Tusk Shells or Scaphopods: tusk or tooth looking shells.
Chitons: Flattened and plated, very primitive looking.
Sand dollars, sea urchins and sea cucumbers are Echinoderms and not mollusks or seashells.
A mollusk is the animal living inside a shell. All mollusks begin as tiny creatures with genetic programming telling it how it will look – basically. Just like we have characteristics of our parents, the shell begins life looking like it’s ancestors.
As the snail inside grows, the mantle continues to add calcium carbonate and conchiolin to the outer surface of the shell to expand it. Because the mantle is constantly rubbing the surface of the shell it becomes smooth and sometimes very shiny. The shells hardness and colors come from the calcium layers deposited by the mantle. The mantle is also responsible for creating the shape, spines and grooves in the shell.
The mollusks choice of food and habitat also may contribute to it’s coloring. As it grows and moves about feeding and doing what mollusks do, it is all the while creating a beautiful work of art unlike any we could ever duplicate.
Please respect all living mollusks and observe them in their habit, but leave them alone – as I’ve said in a previous post, take your camera to the beach.
Reference: Sanibel Seashells Blog