Answering Common Seashell Questions

seashell collection identification

While I write often about the seashells and sea snails I encounter on my travels, I sometimes forget what people really want to know about seashells. On this page I will answer some common seashell questions. I’m not a scientist, so my answers are simple and come from my own observations and research.

  • How do I identify my seashell?

To identify a seashell you’ve found, first you must know if it’s a gastropod or bivalve. This greatly narrows down options. Does your shell come as one piece or two? Spiral shells are gastropods (one-piece) and clams and scallops, as an example, are bivalves. Bivalves were created as two halves even though we most often find only one of the halves.

A shell that can be tricky is the slipper snail shell. For a long time I assumed it was a bivalve, but it is a gastropod because it is made in one piece.

The Slipper Snail is a Gastropod

Next, search for shells that are found locally wherever you found your shell. Even if it’s an uncommon shell, chances are that someone before you has collected the same type of shell. Search blogs, forums, and books that mention shells found in that area of the world. The Bailey-Matthews National Shell Museum is a good place to search.

Also, know seashell lingo. Along with the size, a shell is often described by mentioning the aperture (opening), body, whorls, lip, tooth, columella, hinge, etc. Color is important too, but sometimes the same types of shells can vary widely in color. Here is an excellent page, and site, to direct Florida shell collectors to identifying their shells.

  • What lives inside a shell?

Snails live inside shells. They create the shell as they grow. There are land snails and sea snails. Mollusks are snails of the sea and they make hard coverings (the shell) to conceal their soft bodies. However, once the mollusk dies and leaves an empty shell behind, other creatures can move in. Namely, hermit crabs. Where I live, I find lots of hermit crabs living inside shells.

Other living things can attach themselves to shells also and they don’t really care who is living inside the shell. See the barnacles on the shells below.

  • Are starfish (sea stars) and sand dollars considered to be seashells?

No, sea stars and sand dollars are echinoderms. There is no snail living inside them and they are completely different from snails that build shells. People do tend to call them “shells” mainly because they are found on the beach.

I rarely see sand dollars or sea stars, but I was lucky enough to come across this very tiny sea star on one of our boating trips.

  • How are seashells made? Where do seashells come from?

The snail creates the shell from what it eats and minerals it takes in during it’s life. The snail secretes a substance to build the shell around it and expand upon it’s home as it grows. The shell color also comes from what it eats.

Baby snails hatch from casings left by the parent snail. They begin very small and usually thousands of babies inhabit the casings because it’s so tough to survive in their habitat. This is a good place to mention that you should never collect a living seashell, or shells that have anything living inside or attached to the outside of the shell.

Egg Cases From Two Types of Sea Snail

On the left, the shark’s eye snail made this round, rubber ring that holds babies waiting to hatch. The egg case on the right belongs to some sort of whelk, but I’m not sure which. I’m holding a little Cerith shell next to it for size comparison.

My Interest in Seashells

I don’t know what it would be like to live far from an ocean. I grew up in Massachusetts, but even then I visited Wells Beach in Maine in summer, or went to Hampton Beach in New Hampshire with friends.

I wasn’t paying much attention to seashells back then. Being young, I was focused on more important things. Then, I lived in Florida for most of my adult life. The east coast beaches were only about thirty minutes away and we took the kids to the beach often. Now, the beach is even closer to my house. The point is that an ocean beach has always been within driving distance in my life.

Now that I am older, I prefer to scour the sand for interesting wildlife, plants, and shells that have washed up. At this point, it’s my favorite part of Florida. The crowds of people that have infiltrated this state have made enjoying natural Florida nearly impossible. So, we get on our boat and go off into the rarely visited waterways that snake through the Mosquito Lagoon estuary. My son fishes, and I walk the low-tide sand bars and mangrove island beaches.

Whenever I find something unusual I get photos and add them to my blog. I write about what I see, and the research I do is to inform myself and others. I hope that this will enlighten readers to the amazing world of sea snails and the shells they create. Knowing is appreciating.

I’m very lucky to be able to get out and view this nature for myself. All photography on this page is my own, as is most of the photography on this site. I use some of my photos for the design work I do and sell postcards, paper, puzzles and other products in my online store Seashells by Millhill.

I don’t have a problem with people collecting empty shells, but I am against buying shells from shops. It’s a money-making venture, which causes the death of living sea snails.

Do you have a seashell question? Leave it in the comments and I’ll try to answer it.


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6 thoughts on “Answering Common Seashell Questions

  1. Cheryl

    My family just returned from a trip to Long Island Bahamas. On a tour we were given a queen conch shell to bring home. I am torn about how to clean the outside, there is a layer on the outside that I believe might be called the periostracum. It is brownish and gives the conch more color so my daughter wants it left on. It’s pealing off in places and I wonder if the conch would look better with it removed? Do most people remove this?

    1. Pam

      I’ve never found a queen conch, so I don’t know specifically about that shell. I have had horse conchs and other shells with periostracum, which was dark brown. I’ve found that it eventually flakes off on it’s own, although I do have one horse conch which is still partially covered. I think is looks fine. I like to leave the shells looking natural. Maybe just leave your shell as it is and see what happens, but that is up to you. The sun will help it to dry and flake off, but sun also fades shells! I honestly don’t know what most people do, but maybe they will chime in.

  2. BoardNH

    Great post Mummy! Very informative. I don’t think many of us give a second thought as to how sea shells are made, or where they come from. It’s amazing that these tiny creatures grow their own shells and essentially their own homes. I wish more people stopped, even if only for a second, to appreciate the creatures, big and small, that live in this world. It’s an important message to get out to tourists not to buy seashells from the store. They were once living, and lost their lives for a few dollars. It’s so sad.

    On a happier note, that baby starfish is so cute! 🙂 I couldn’t imagine not living within driving distance from the ocean. It’s such a magical place, with so much to explore and much to learn about. Keep educating people. It’s a great way to initiate change, and help people understand why even the smallest creatures are so vital to our world! 🙂 xoxoxo

    1. Pam

      Thanks for reading honey, and the encouraging words. Sometimes people just need a wake-up call. At least a lot of what I find (like the sea star) is away from crowds of people so no one will mess with it. 🐚

    1. Pam

      Not at all Emma! I never thought about what made shells until just a few years ago! Sometimes we just need the info.

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