''Micropleurotoma melvilli'' 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 in the family

Horaiclavidae Horaiclavidae is a family of predatory sea snails, marine gastropod mollusks in the superfamily Conoidea. In 2011 this family was split off from the family Pseudomelatomidae (formerly the subfamily Crassispirinae McLean, 1971) by Bouchet P., Ka ...

Description

The length of the shell attains 6 mm, its diameter 2.6 mm. (Original description) The spire of the small, elongate, shell is well raised, varying a good deal in the relative proportions of length and breadth. The colour is hyaline white. 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 floral ...

s, turreted, carinated, regularly but slowly increasing. The suture is well marked, with a small strap-like rim below it. 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 ...

is large, white, smooth and elevated. The remaining whorls are marked by a strong spiral keel, which is either smooth or bears acute nodules lines of growth well marked. The aperture is fairly broad. The columella is twisted at the base. Sykes E. R. (1906). "On the Mollusca procured during the "Porcupine" Expeditions 1869–1870. Supplemental notes, part 3". ''Proceedings of the Malacological Society of London'' 7: 173–190.(described as ''Spirotropis melvilli'')

Distribution

This species occurs in the demersal zone of the Atlantic Ocean off Portugal at depths between 1340 m and 2000 m.

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

External links

Rex, Michael A., et al. "A source-sink hypothesis for abyssal biodiversity." The American Naturalist 165.2 (2004): 163–178.

Olabarria, Celia. "Faunal change and bathymetric diversity gradient in deep-sea prosobranchs from Northeastern Atlantic." Marine, Freshwater, and Wetlands Biodiversity Conservation. Springer Netherlands, 2006. 317–334.

Bouchet, Philippe, and Marco Taviani. "The Mediterranean deep-sea fauna: pseudopopulations of Atlantic species?." Deep Sea Research Part A. Oceanographic Research Papers 39.2 (1992): 169–184.
{{DEFAULTSORT:Micropleurotoma Melvilli melvilli Gastropods described in 1906