''Crepidula ustulatulina'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of small

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

, a slipper snail, a marine

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Calyptraeidae The Calyptraeidae are a family of small to medium-sized marine prosobranch gastropods.MolluscaBase. Calyptraeidae Lamarck, 1809. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=141 on ...

, the slipper snails or slipper limpets, cup-and-saucer snails, and Chinese hat snails. This species occurs in the Western

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

Distribution

This recently named species is known to occur in the

Gulf of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...

and the east coast of

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

Description

''Crepidula ustulatulina'' can be distinguished from other species of ''Crepidula'' by the following suite of characters. The shell is small (usually less than 1.5 cm), smooth, and convex. It is often cream with distinct chestnut brown spots or streaks, sometimes it is brown overall with darker spots or streaks. The internal septum is flat and white, and the animal's left side usually extends somewhat farther forward than does the right side. The margin is straight or slightly bowed. There is an oval muscle scar just anterior to the shelf on the animal's right side. The small apex is usually directly posterior and is slightly rostrate in animals living on small snails but not in those from flat substrates. The external body color is light to dark gray with opaque white or cream on the tips of the tentacles and the lips. There are usually large yellow pigment splotches on the mantle, neck and sometimes foot, visible only in life. The maximum recorded

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses Science Biology * Seashell, a hard outer layer of a marine ani ...

length is 13.2 mm. The shell is usually cream with brown mottling. The visible soft parts are mostly grey.

Habitat

''Crepidula ustulatulina'' is common in the low intertidal and shallow subtidal, often on dead clam shells and on columbellids and cerithids in or near sea grass. Those living on large flat substrates are oval in shape but those on small snails have highly arched and often compressed on the left side. Minimum recorded depth is 0 m. Maximum recorded depth is 1 m.

Development

The large eggs (300-340

μm The micrometre (Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a unit of length in the International System ...

) produce direct developing embryos with a smooth shell, and an average length of 744 μm at hatching. The large embryonic velum is not absorbed prior to hatching and the embryo hatches as a swimming pediveliger. The non-feeding larvae settle within an hour of hatching. There are between 3 and 16 eggs in each capsule and the number of eggs per capsule increases with female size.

References

* Say, T. 1822. An account of the marine shells of the United States. J. Acad. Nat. Sci. Philadelphia 2: 221–227.

External links

Info from the Smithsonian Marine Station at Fort Pierce website, a detailed report by the author of the species, R. Collin of the Smithsonian Tropical Research Institute

Malacolog info on this species
* http://stri.si.edu/sites/collinlab/tree_species/details.php?id=2 * C. ustulatulina in the Indian River Lagoon BioInventory {{Taxonbar, from=Q5184270 Calyptraeidae Gastropods described in 2002