Living Sanibel: Lettered olive and apple murex
Lettered olive
The best location to find a living lettered or golden olive is along the beaches and near the sandy bottoms of the passes and shoals. Named for is dark surface markings that vaguely resemble blurry cuneiform writing, this shell is a highly prized find. Although it might appear that the olives you find at a shell shop have been mechanically polished, this process is done by the shellfish itself. When moving, the fleshy mantle of the live animals extends around the outside of the shell to protect it. This constant rubbing of the outer surface, coupled with the tiny fragments of sand and grit between the shell and the living organism, serve to polish the shell over time.
The far more uncommon golden olive, which is a color variant of the lettered olive, can also be found along the surf line. If the water is calm enough, you can track either of them by following their trail through the soft sand. It is in this surf zone where they feed on coquinas, small clams and other shellfish. Olives, like many gastropods, are carnivores. Because they are so attractive, the Calusa as well as many Native American tribes, used lettered olives to make jewelry and other decorative objects. A handful of birds are able to take and eat olives as are stingrays, sharks and other predatory gastropods.
Apple murex
Ranging from North Carolina to Brazil, the apple murex is one of the most abundant murex shells found in Florida and the West Indies. It feeds predominately on the common Eastern oyster, boring almost perfectly round holes into its shells. Given a thick enough oyster, this slow drilling may take the apple murex weeks to complete but this pales in comparison with some species of South Pacific drills.
Scientists have now determined that some small drills, dining on much larger and thicker clams and oysters, may take up to eight months to drill through the shell and into the soft, edible parts of the animal! Imagine waiting more than six months, without appetizers, for your dinner.
Although this is a fairly common shell to find washed up along the beach, it is nowhere near as easy to find alive. Look for it beyond the surf zone, preferably with a mask and snorkel, in water from three to ten feet. Finding one will probably be more related to water clarity than to any other factor.
The apple murex is preyed upon by other carnivorous gastropods, including other murex species. It is also eaten by rays and sharks.
This is an excerpt from The Living Gulf Coast – A Nature Guide to Southwest Florida by Charles Sobczak. The book is available at all the Island bookstores, Baileys, Jerry’s and your favorite online sites.