The Florida Rock Snail
The Florida Rock Snail, Stramonita haemastoma floridana (Conrad, 1837), although relatively common in other parts of Florida, is locally uncommon. This happens because populations of the species need ample rock areas to thrive, and rocks are not prevalent on the barrier islands of Southwest Florida. Rock Snails in the genus Stramonita are known to feed on Oysters and Mussels and may be able to “attack” those prey in groups, to maximize feeding efficiency. Their feeding behaviors include chipping away at the shell margins of Oysters and Mussels using their teeth (called radula) and acid secretions. Rock Snail egg capsules are column-shaped, measuring about 3/8 inch. “Spent” egg capsules typically show a purplish color, a leftover from the liquid surrounding the embryonic snails.
The Florida Rock Snail, Stramonita haemastoma floridana, shell and (on right) empty egg capsules.