''Neverita duplicata'',

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often con ...

the shark eye, 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), ...

predatory Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill ...

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 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 ...

Naticidae Naticidae, common name moon snails or necklace shells, is a family (biology), family of medium to large-sized predatory sea snails, marine (ocean), marine gastropod molluscs in the clade Littorinimorpha. The shells of the species in this family a ...

, the moon snails. In 2006, a paper was published which made it clear that a second, very similar, species with a smaller range of distribution also lives in part of the range inhabited by ''Neverita duplicata''. The second species had previously been considered to be simply a form of ''N. duplicata'', but it is now recognized as '' Neverita delessertiana''.Huelsken, T. ''et al.'' (2006) ''Neverita delessertiana'' (Recluz in Chenu, 1843): a naticid species (Gastropoda:

Caenogastropoda Caenogastropoda is a taxonomic subclass of molluscs in the class Gastropoda. It is a large diverse group which are mostly sea snails and other marine gastropod mollusks, but also includes some freshwater snails and some land snails. The subcla ...

) distinct from ''Neverita duplicata'' (Say, 1822) based on molecular data, morphological characters, and geographical distribution. ''

Zootaxa ''Zootaxa'' is a peer-reviewed scientific mega journal for animal taxonomists. It is published by Magnolia Press (Auckland, New Zealand). The journal was established by Zhi-Qiang Zhang in 2001 and new issues are published multiple times a week ...

'', 1-25
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Distribution

This is a common western

Atlantic The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for se ...

species. It is found from

Massachusetts Massachusetts ( ; ), officially the Commonwealth of Massachusetts, is a U.S. state, state in the New England region of the Northeastern United States. It borders the Atlantic Ocean and the Gulf of Maine to its east, Connecticut and Rhode ...

and other parts of

New England New England is a region consisting of six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York (state), New York to the west and by the ...

, south to

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 ...

and other states on 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 ...

, south to

Honduras Honduras, officially the Republic of Honduras, is a country in Central America. It is bordered to the west by Guatemala, to the southwest by El Salvador, to the southeast by Nicaragua, to the south by the Pacific Ocean at the Gulf of Fonseca, ...

Description

The shell has a flattened globular shape, and reaches about in maximum dimension. The color of the shell is variable, but is often a greyish brown. The central

apex The apex is the highest point of something. The word may also refer to: Arts and media Fictional entities * Apex (comics) A-Bomb Abomination Absorbing Man Abraxas Abyss Abyss is the name of two characters appearing in Ameri ...

of the shell is often a dark blue in fresh shells, which can make the shell somewhat resemble an

eye An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the ey ...

. On the underside, there is a large brown

callus A callus (: calluses) is an area of thickened and sometimes hardened skin that forms as a response to repeated friction, pressure, or other irritation. Since repeated contact is required, calluses are most often found on the feet and hands, b ...

which partly blocks the

umbilicus Umbilicus may refer to: *The navel or belly button *Umbilicus (mollusc), a feature of gastropod, Nautilus and Ammonite shell anatomy *Umbilicus (plant), ''Umbilicus'' (plant), a genus of over ninety species of perennial flowering plants *Umbilicus ...

of the shell. 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 82 mm.Welch J. J. (2010). "The "Island Rule" and Deep-Sea Gastropods: Re-Examining the Evidence". '' PLoS ONE'' 5(1): e8776. .

Habitat

This moon snail is found on sandy shores just below the low tide line. In most of its range, the empty shell is very commonly washed up on beaches, as also is the operculum and the

sand collar Sand collars are the characteristic egg masses of one family of sea snails, the moon snails, marine (ocean), marine gastropod mollusks in the family (biology), family Naticidae. These egg masses are often found washed up either whole, or sometime ...

. The minimum recorded depth for this species is 0 m; the maximum recorded depth is 58 m.

Feeding habits

The shark eye (like all moon snails) is

predator Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...

y, feeding mainly on

bivalves Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed by a calcified exoskeleton consis ...

buried in the sand. This snail drills a neat " countersunk" circular hole through the shell of its prey species, and then feeds on the soft tissue within.

Gallery

File:Atlantic Moon Snail 001.jpg, A model of a live individual of ''Neverita duplicata'' File:Neverita duplicata 003.jpg, Apical view of ''Neverita duplicata'' File:Neverita duplicata 002.jpg, Lateral view of the same shell File:Neverita duplicata 001.jpg, Umbilical view of the same shell File:Neverita_duplicata_01.JPG, Fossil ''Neverita duplicata'' from the Pliocene of Florida

References

External links

''Neverita duplicata'' at Jax Shells

''Neverita duplicata''
Gastropods.com, accessed 16 January 2011 {{Taxonbar, from=Q3175328 Naticidae Gastropods described in 1822