Excerpts from Jim Conrad's
from the February 15, 2015 Newsletter issued from Río Lagartos, on the north-central coast of Yucatán, MÉXICO
APPLE MUREX SEASHELL
An interesting gastropod-type, sea-snail-sort of seashell had washed onto the Gulf of Mexico beach, more ornamented than most, as shown above. Several kinds of shells more or less like this one wash onto our beaches but this one was distinctive because of the sides of its slender neck, which flare outwards into wavy wings. Below, a shot from below provides another view:
Volunteer identifier Bea in snowy Ontario quickly identified this as the Apple Murex, PHYLLONOTUS POMUM, a species whose shells on living beings are more colorful and more ornamented with warty ridges, wrinkles, concentric rings and such. You might enjoy seeing a variety of shells of this species at http://www.gastropods.com/6/Shell_1416.shtml.
Apple Murexes occupy shallow waters of the western Atlantic from North Carolina in the US south through the Gulf of Mexico and the Caribbean to northern Brazil. A website in Venezuela says that the local people there harvest Apple Murexes by diving. They eat the shells'contents and sell the prettier shells to tourists. Ours is a small one; in some places they grow to a height of five inches (13cm).
During low tides Apple Murexes bury themselves in the sand. If you happen to be on a beach exposed at low tide as the tide starts returning, they "pop from the sand," as beachwalkers like to say.
They make their living by drilling holes in oysters and eating the contents.