''Mitromorpha alphonsiana'' is a species of

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 ...

Mitromorphidae.

Description

The length of the shell attains 6 mm, its diameter 2.75 mm. The small shell has a biconic shape and an acuminate apex. The shell has a white color. The middle of the

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 is ornated with white and yellow dots, alternating on the ribs, below two series of granules, cut by subsutural striae. Those two rows of dots on the superior part have a violet-rose color only on the first two whorls. This color nuance changes on 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 ...

. Here the two upper rows of dots are white. The shell contains 7–8 whorls, of which 2–3 smooth and milky white whorls 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 called ...

. The others are convex with an indistinct suture. The longitudinal ribs are dense and are crossed by two transverse striae on each whorl, subsutarally sulcate and decussate by small lirae. The superior part of the narrow, oblique body whorl is slightly rounded, the inferior part attenuate and elongate. The superior part of the columella is concave, inflated at the middle. The convex outer lip is incrassate and sinuate at the suture and has a sharp margin.Hervier, J. "Le genre Columbella dans l’Archipel de la Nouvelle-Calédonie." Journal de Conchyliologie 46 (1899): 305–391
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Distribution

This marine species occurs off

New Caledonia ) , anthem = "" , image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg , map_alt = Location of New Caledonia , map_caption = Location of New Caledonia , mapsize = 290px , subdivision_type = Sovereign st ...

and the Tuamotu Islands.

References

External links

MNHN, Paris: ''Mitromorpha alphonsiana''
* *
Salvat, Bernard, and Jean Tröndlé. "Biogéographie des mollusques marins de Polynésie française." Revue d’Ecologie (Terre et Vie) 72.3 (2017): 215–257
{{DEFAULTSORT:Mitromorpha Alphonsiana alphonsiana Gastropods described in 1899