
Northern Moon Shell
It may seem odd to be finding seashells in the snow, but a couple of days ago, I found a Northern Moon Shell while walking along the Salt Marsh Trail off Bissett Road. It was cracked, most likely by a seagull that had broken it open, either with its bill or by smashing it on a rock.
Moon snails are carnivores that bore their way into other seashells such as clams using a rasplike tongue. If you’ve ever picked a clam shell on the beach that has a small, perfectly circular hole in it, it was likely eaten by a moon snail.
The live body of a moon snail is surprisingly large and covers most of the shell when it’s on the prowl. The shell itself can be up to 7 inches wide. Seagulls probably consider them well worth the trouble of cracking open, as their meat would provide a hearty meal.

Northern Moon Shell with shells showing bored holes
I didn’t know there was a shell called a “northern moon shell”. How cool! Seashells in the snow sound almost romantic… also didn’t know the body of a snail would be that large. I’ll bet the gulls do find that a tasty treat.
Thanks for dropping by Kathy. Before you think too much more of these shells being associated with anything romantic…
I forgot to mention that these lovely creatures are also cannibalistic. I have a small moon snail with a perfectly round hole bored through its shell. Nice.
Cannibalistic? Oh dear…forget that romantic streak! But that shell with the round hole sounds neat. You could wear it as a necklace?
Kathy, I added an image of an average sized moon shell along with a clam shell and a small moon shell showing the bored holes. I don’t think the hole in the small moon shell is placed in a good position for threading with a chain or rope but a jeweler might think otherwise.
I love moon snails! When extended, their bodies are surprisingly massive and covered in a thick slime which they often use as a defense against predatory sea stars. If something else threatens them, they can completely withdraw into their shells (which looks utterly impossible if you could see one fully extended) and close the hard, door-like operculum to protect their soft parts. Besides which they are blazingly fast in snail speeds. 😀 They are absolutely fascinating creatures. Great post!
Waven, I didn’t know they used their slime to defend themselves and I didn’t know they were so speedy. Thanks so much for the added info 🙂