''Anatoma crispata'' 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 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 ...

micromollusk A micromollusc is a shelled mollusc which is extremely small, even at full adult size. The word is usually, but not exclusively, applied to marine molluscs, although in addition, numerous species of land snails and freshwater molluscs also ...

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 ...

Anatomidae Anatomidae is a family of small sea snails, marine gastropod mollusks in the clade Vetigastropoda Vetigastropoda is a major taxonomic group of sea snails, marine gastropod mollusks that form a very ancient lineage. Taxonomically the Vetig ...

Description

The length of the shell varies between 1 mm and 4 mm. The globose, pearly white shell slopes toward the periphery. It is delicate, semitransparent, and glossy. The

sculpture Sculpture is the branch of the visual arts that operates in three dimensions. Sculpture is the three-dimensional art work which is physically presented in the dimensions of height, width and depth. It is one of the plastic arts. Durable sc ...

consists of numerous fine, curved, longitudinal ribs, interrupted by the slit fasciole, closer on the base, intersected by minute spiral striae in the interstices. The thin epidermis is caducous, and pale yellowish-brown. The

spire A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spire ...

is usually rather depressed, but variable. The four ;

whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). In nature File:Photograph and axial plane floral diagra ...

s are flattened above, rapidly enlarging. The slit is long and narrow, nearly central. The slit fasciole is deep, striated across. The edges are somewhat thick, sharp, and prominent . The rounded

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

is oblique. The

peristome Peristome (from the Greek language, Greek ''peri'', meaning 'around' or 'about', and ''stoma'', 'mouth') is an anatomical feature that surrounds an opening to an organ or structure. Some plants, fungi, and shelled gastropods have peristomes. In mo ...

is continuous. The outer

lip The lips are a horizontal pair of soft appendages attached to the jaws and are the most visible part of the mouth of many animals, including humans. Mammal lips are soft, movable and serve to facilitate the ingestion of food (e.g. sucklin ...

is thin. The inner lip is folded back on the

columella Lucius Junius Moderatus Columella (, Arabic: ) was a prominent Roman writer on agriculture in the Roman Empire. His in twelve volumes has been completely preserved and forms an important source on Roman agriculture and ancient Roman cuisin ...

. 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 ...

is deep, but exposing only the

body whorl The body whorl is part of the morphology (biology), morphology of the gastropod shell, shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk ...

. The operculum is very delicate, with numerous whorls, the last large.

Distribution

This species has a wide distribution. It occurs in circumarctic waters (

Greenland Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenlan ...

, Canada,

Baffin Island Baffin Island (formerly Baffin Land), in the Canadian territory of Nunavut, is the largest island in Canada, the second-largest island in the Americas (behind Greenland), and the fifth-largest island in the world. Its area is (slightly smal ...

, Queen Elisabeth Islands,

Labrador Labrador () is a geographic and cultural region within the Canadian province of Newfoundland and Labrador. It is the primarily continental portion of the province and constitutes 71% of the province's area but is home to only 6% of its populatio ...

), in European waters, the

Mediterranean Sea The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern Eur ...

, in the Atlantic Ocean off the

Azores The Azores ( , , ; , ), officially the Autonomous Region of the Azores (), is one of the two autonomous regions of Portugal (along with Madeira). It is an archipelago composed of nine volcanic islands in the Macaronesia region of the North Atl ...

Cape Verde Cape Verde or Cabo Verde, officially the Republic of Cabo Verde, is an island country and archipelagic state of West Africa in the central Atlantic Ocean, consisting of ten volcanic islands with a combined land area of about . These islands ...

, Angola; in the Northwest Atlantic Ocean (

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 ...

, the

Bahamas The Bahamas, officially the Commonwealth of The Bahamas, is an archipelagic and island country within the Lucayan Archipelago of the Atlantic Ocean. It contains 97 per cent of the archipelago's land area and 88 per cent of its population. ...

), in the

West Indies The West Indies is an island subregion of the Americas, surrounded by the Atlantic Ocean, North Atlantic Ocean and the Caribbean Sea, which comprises 13 independent island country, island countries and 19 dependent territory, dependencies in thr ...

, in the Pacific Ocean off

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

and Japan. This species has been cited from multiple localities throughout the North Atlantic, but most records are inaccurate due to confusion with Anatoma aspera (mostly), A. tenuisculpta and A. orbiculata. Therefore, records which are not backed by an illustration or a specimen should be disregarded.

References

* Geiger, D.L. (2012). Monograph of the little slit shells. Volume 1. Introduction, Scissurellidae. pp. 1–728. Volume 2. Anatomidae, Larocheidae, Depressizonidae, Sutilizonidae, Temnocinclidae. pp. 729–1291. Santa Barbara Museum of Natural History Monographs. Number 7

External links

*
Fleming, J. (1828). A history of British animals, exhibiting the descriptive characters and systematical arrangement of the genera and species of quadrupeds, birds, reptiles, fishes, Mollusca, and Radiata of the United Kingdom; including the indigenous, extirpated, and extinct kinds, together with periodical and occasional visitants. Edinburgh, Bell & Bradfute / London, James Duncan. Pp. i–xxii, 1–565

Høisæter T. & Geiger D.L. (2011) Species of Anatoma (Gastropoda: Anatomidae) in Norwegian and adjacent waters, with the description of two new species. The Nautilus 125(3): 89–112

Lovén, S. L. (1846). Index Molluscorum litora Scandinaviae occidentalia habitantium. Öfversigt af Kongliga Vetenskaps Akademiens Förhandlingar. (1846): 134–160, 182–204

Micali P. & Geiger D.L. (2015). Additions and corrections to the Scissurellidae and Anatomidae (Gastropoda Vetigastropoda) of the Mediterranean Sea, with first record of Sinezona semicostata Burnay et Rolán, 1990. Biodiversity Journal. 6(3): 703–708

Nekhaev, I. O.; Krol, E. N. (2020). A review of the genus Anatoma in the Eurasian Arctic seas (Gastropoda: Vetigastropoda: Anatomidae). Zoosystematica Rossica, (Zoosyst. Rossica). 29(1): 128–137
{{DEFAULTSORT:Anatoma Crispata Anatoma Gastropods described in 1828 Molluscs of the Atlantic Ocean Molluscs of the Pacific Ocean Molluscs of the Mediterranean Sea