''Entemnotrochus adansonianus'', common name Adanson's slit shell, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

, a marine

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Pleurotomariidae Pleurotomariidae, common name the "slit snails", is a family of large marine gastropods in the superfamily Pleurotomarioidea of the subclass Vetigastropoda. This family is a very ancient lineage; there were numerous species in the geological pas ...

. ;Subspecies: * ''Entemnotrochus adansonianus adansonianus'' (

Crosse Crosse is a surname, and may refer to: * Andrew Crosse (1784–1855), British amateur scientist * Charles Crosse, British rugby * Charles G. Crosse, American physician and politician * Edmond Francis Crosse (1858-1941), first Archdeacon of Cheste ...

Fischer Fischer is a German occupational surname, meaning fisherman. The name Fischer is the fourth most common German surname. The English version is Fisher. People with the surname A * Abraham Fischer (1850–1913) South African public official * Ad ...

, 1861) * ''Entemnotrochus adansonianus bermudensis'' Okutani & Goto, 1983

Description

The length of the shell varies between 80 mm and 190 mm. This attractive species has a pale yellowish-fleshy color with numerous, irregular, reddish spots, sometimes vivid, sometimes more or less effaced. The shell has a trochiform shape above, but is plano-convex beneath and concave in the middle. It is concentrically costate-sulcate with granulose ribs. It has many longitudinal wrinkles. The acuminate apex is smooth and yellowish. The 11

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). Whorls in nature File:Photograph and axial plane floral ...

s increase slowly and are rather planulate at the sutures. The shell is unequally divided by the slit fasciole. Below it is traversed by 7 to 8 spiral granose ribs, above it with longitudinal, oblique, rather separated striae and two spiral, slightly marked series of granules; The

body whorl The body whorl is part of the morphology of the 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. In gastropods In gastropods, the b ...

is obtusely bicarinate. The slit fascicle has a semicircular, delicate, impressed stride. It has a round and very deep, pervious umbilicus. The species has a (thin yellow in juvenile examples) operculum that completely seals the subquadrate

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An opt ...

. The shell is pearly within.

Distribution

''E. adansonianus'' is endemic to the

West Indies The West Indies is a subregion of North America, surrounded by the North Atlantic Ocean and the Caribbean Sea that includes 13 independent island countries and 18 dependencies and other territories in three major archipelagos: the Greater A ...

and

Caribbean The Caribbean (, ) ( es, El Caribe; french: la Caraïbe; ht, Karayib; nl, De Caraïben) is a region of the Americas that consists of the Caribbean Sea, its islands (some surrounded by the Caribbean Sea and some bordering both the Caribbean Se ...

region.Oliver, A.P.H. (2004). ''Guide to Seashells of the World.'' Buffalo: Firefly Books. 17. A very few of these rare slit shells that reside at depths between 150–240 metres have been dredged and (crabbed examples) trapped. This species also occurs on the

Mid-Atlantic Ridge The Mid-Atlantic Ridge is a mid-ocean ridge (a divergent or constructive plate boundary) located along the floor of the Atlantic Ocean, and part of the longest mountain range in the world. In the North Atlantic, the ridge separates the North Ame ...

References

* Crosse, H. & Fischer, P., 1861. ''Observation sur le genre Pleurotomaire, et description d'une deuxième espèce vivante appartenant au même genre.'' Journal de Conchyliologie 9: 155–167 * Fischer-Piette, E., 1950. ''Listes des types décrits dans le Journal de Conchyliologie et conservés dans la collection de ce journal.'' Journal de Conchyliologie 90: 8–23 * F. R. Woodward, 1989. ''Samuel Archer and ''Entemnotrochus adansoniana'' (formerly ''Pleurotomaria adansoniana'').'' Proceedings of the Birmingham Natural History Society 26 (1): 25–28 upplement to Woodward, 1963 * Turgeon, D.D., et al. 1998. ''Common and scientific names of aquatic invertebrates of the United States and Canada''. American Fisheries Society Special Publication 26 page(s): 57 * Williams S.T., Karube S. & Ozawa T. (2008) M''olecular systematics of Vetigastropoda: Trochidae, Turbinidae and Trochoidea redefined.'' Zoologica Scripta 37: 483–506 * Rosenberg, G., F. Moretzsohn, and E. F. García. 2009. ''Gastropoda (Mollusca) of the Gulf of Mexico'', Pp. 579–699 in Felder, D.L. and D.K. Camp (eds.), Gulf of Mexico–Origins, Waters, and Biota. Biodiversity. Texas A&M Press, College Station, Texas.

External links

*
MNHN, Paris: holotype
{{DEFAULTSORT:Entemnotrochus Adansonianus Pleurotomariidae Gastropods described in 1861