''Raphitoma bracteata'' 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 ...
Raphitomidae
Raphitomidae is a family of small to medium-sized sea snails, marine gastropod mollusks in the superfamily Conoidea.Bouchet P. & Rocroi J.-P. (Ed.) (2005). "Classification and nomenclator of gastropod families". '' Malacologia'' 47(1-2). . 3 ...
.
Description
The shell reaches a length of 13 mm, and a diameter of 6 mm.
The subfusiform, turreted, white shell has a pointed
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 ...
. It contains 6
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, of which only 1½ whorl in the
protoconch
A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also calle ...
. The subsequent whorls are convex with axial, close and elevated ribs and elevated, decurrent, parallel threads, forming nodules on the cross-points. The suture is impressed. The
body whorl is ventrose. The subovate
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 ...
measures half the length of the shell. 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 ...
is slightly twisted at its base. The open
siphonal canal
The siphonal canal is an anatomical feature of the shells of certain groups of sea snails within the clade Neogastropoda. Some sea marine gastropods have a soft tubular anterior extension of the mantle called a siphon through which water ...
is very short. The outer lip is rounded, very convex, incrassate inwards and ending in a V-shape sinus at its top.
Distribution
The holotype of this marine species was found off
Tunisia
)
, image_map = Tunisia location (orthographic projection).svg
, map_caption = Location of Tunisia in northern Africa
, image_map2 =
, capital = Tunis
, largest_city = capital
, ...
.
References
* Gofas, S.; Le Renard, J.; Bouchet, P. (2001). Mollusca. in: Costello, M.J. et al. (eds), European Register of Marine Species: a check-list of the marine species in Europe and a bibliography of guides to their identification. Patrimoines Naturels. 50: 180-213
* Giannuzzi-Savelli R., Pusateri F. & Bartolini S. (2018). A revision of the Mediterranean Raphitomidae (Gastropoda: Conoidea) 5: loss of planktotrophy and pairs of species, with the description of four new species. Bollettino Malacologico. 54, supplement 11: 1-77
External links
Pallary P. (1904-1906). Addition à la faune malacologique du Golfe de Gabès. Journal de Conchyliologie. 52: 212-248, pl. 7
54: 77-124, pl. 4">904">Pallary P. (1904-1906). Addition à la faune malacologique du Golfe de Gabès. Journal de Conchyliologie. 52: 212-248, pl. 7 [1904 54: 77-124, pl. 4*
{{DEFAULTSORT:Raphitoma Bracteata
bracteata
Gastropods described in 1904">Raphitoma">bracteata
Gastropods described in 1904