''Tritia corniculum'', common name the horn nassa, is a
species
In biology, a species is the basic unit of Taxonomy (biology), 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 ...
of
sea snail, a marine
gastropod 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 es ...
in the
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
Nassariidae
The Nassariidae, Nassa mud snails (USA), or dog whelks (UK), are a taxonomic family of small to medium-sized sea snails, marine gastropod mollusks in the clade Neogastropoda.
"Dog whelk" also refers to '' Nucella lapillus''.
Shell descripti ...
, the Nassa mud snails or dog whelks.
[Marshall, B. (2016). Tritia cornicula (Olivi, 1792). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=876831 on 2016-05-18]
Spelling
Originally introduced in the binomen ''Buccinum corniculum'', the specific
epithet
An epithet (, ), also byname, is a descriptive term (word or phrase) known for accompanying or occurring in place of a name and having entered common usage. It has various shades of meaning when applied to seemingly real or fictitious people, di ...
is to be considered a noun (meaning "a small horn on a soldier's helmet") and is invariant.
Description
The ovate, conical shell is thick, smooth, and pointed at its summit. Length varies between and . 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. Spires are ...
is composed of six or seven slightly distinct
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 flo ...
s. The suture is moderately deep. There are a few transverse striae at the base of the
body whorl. The
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 ...
is pretty large, ovate, violet-colored or chestnut, and dilated towards the middle. The outer
lip is sharp and denticulated within. The left lip is thick and partially covers the
columella
Lucius Junius Moderatus Columella (; Arabic: , 4 – ) was a prominent writer on agriculture in the Roman Empire.
His ' in twelve volumes has been completely preserved and forms an important source on Roman agriculture, together with the ...
in its whole extent. The epidermis is thin, of a greenish- or reddish-brown, and beneath are perceived transverse zones, with spots of a slate- or violet-gray color, along with a decurrent white band, articulated with brown or bay-colored spots upon the suture.
[Kiener (1840). General species and iconography of recent shells : comprising the Massena Museum, the collection of Lamarck, the collection of the Museum of Natural History, and the recent discoveries of travellers; Boston :W.D. Ticknor,1837](_blank)
(described as ''Buccinum fasciolatum'')
Distribution
This species occurs in 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 north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ...
and in the Atlantic Ocean off
West Africa
West Africa or Western Africa is the westernmost region of Africa. The United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Mali, Mau ...
and the
Azores
)
, motto=
( en, "Rather die free than subjected in peace")
, anthem=( en, "Anthem of the Azores")
, image_map=Locator_map_of_Azores_in_EU.svg
, map_alt=Location of the Azores within the European Union
, map_caption=Location of the Azores wi ...
.
''Tritia corniculum'' var. ''minor''
File:Tritia corniculum var. minor 02.JPG, Brown form
File:Tritia corniculum var. minor 01.JPG, Spotted form
References
* Cernohorsky W. O. (1984). ''Systematics of the family Nassariidae (Mollusca: Gastropoda).'' Bulletin of the Auckland Institute and Museum 14: 1–356
* Gofas, S.; Le Renard, J.; Bouchet, P. (2001). Mollusca, in: Costello, M.J. et al. (Ed.) (2001). ''European register of marine species: a check-list of the marine species in Europe and a bibliography of guides to their identification''. Collection Patrimoines Naturels, 50: pp. 180–213
External links
*
{{DEFAULTSORT:Tritia corniculum
corniculum
Gastropods described in 1792