English: Crepidula fornicata (Linnaeus, 1758) - common Atlantic slipper snail shell from Florida, USA.

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.

Seen here is a common Atlantic slipper snail, Crepidula fornicata, an unusual gastropod that lacks a conical, strongly coiled shell. This animal is notable for its odd reproductive behavior - multiple individuals can be found in mating stacks (see: www.flickr.com/photos/jsjgeology/25957487582 ). 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: Marco Island, Gulf of Mexico coast of southern Florida, USA

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Info. at:

en.wikipedia.org/wiki/Common_slipper_shell