ShellSanibel
Read the beach.
Apple murex
Phyllonotus pomum
fairly common · 2–4 in (5–10 cm)
How to tell it
Knobbly and rugged, with three heavy flanged varices running down the body and a rough, frilled texture. Brown and cream, often with a stained-looking aperture.
What it gets confused with
Other murexes are spinier and less common here. Worn apple murex can lose most of its frilling and read as a generic lump.
Where it turns up
Around structure and the passes more than the open beach.
Alive or empty
A drill — it bores neat round holes in bivalves. Frequently found alive.
Worth knowing
Those tidy circular holes in other shells on the beach are murex and moon-snail work.
Taking live shells is prohibited in Lee County
That includes anything with the animal still in it, and sand dollars, sea stars and urchins whether or not they look alive. If it moves, if it closes, if it is anchored to the sand — put it back where you found it, the right way up.
A shell with an animal in it is not a souvenir that has been left out. It is the animal’s house, and the beach is not producing spares.