Crepidula fornicata (Linnaeus, 1758) - common Atlantic slipper snails in Florida, USA (December 2013).

The gastropods (snails & slugs) are a group of molluscs that occupy marine, freshwater, and terrestrial environments. Most gastropods have a calcareous external shell (the snails). Some lack a shell completely, or have reduced internal shells (the slugs & sea slugs & pteropods). Most members of the Gastropoda are marine. Most marine snails are herbivores (algae grazers) or predators/carnivores.

Shown above are common Atlantic slipper snails that are attached to a fighting conch, Strombus alatus. Slipper snails are unusual gastropods in that they lack a conical, strongly coiled shell. They are also famous for their odd reproductive behavior - they are often found in mating stacks (see above left). Large stacks have the oldest, largest females at the bottom and a young male at the top. After another slipper snail is added to a stack, the top male morphs into a female (sequential hermaphrodism).

Many misperceive the species name "fornicata" as being a reference to the mating stacks. The root word of "fornicata" is Latin for "arch", and actually refers to the strongly convex, arched shape of the shell. "Fornicate" means what it does today because prostitutes in ancient Rome often loitered under city arches.

Classification: Animalia, Mollusca, Gastropoda, Calyptraeidae

Locality: marine beach near the southern end of the western shoreline of Cayo Costa Island, Gulf of Mexico coast of southwestern Florida, USA (vicinity of 26° 36' 51.30" North latitude, 82° 13' 24.39" West longitude)

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