''Munditia meridionalis'' 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 ...

of small

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 Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

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 ...

Liotiidae Liotiidae is a family of small sea snails, marine gastropod mollusks in the clade Vetigastropoda (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).Gofas, S. (2013). Liotiidae Gray, 1850. Accessed through: World Register of ...

.Bouchet, P. (2013). ''Munditia meridionalis'' (Melvill & Standen, 1912). Retrieved through:

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms. Content The content of the registry is edited and maintained by scientific specialist ...

at http://www.marinespecies.org/aphia.php?p=taxdetails&id=197289 on 3 September 2013

Description

The height of this minute shell attains 0.75 mm and its diameter 0.50 mm. The delicate, white-gray shell has a depressed trochoidal shape and is deeply umbilicate. it contains 4

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. The nuclear whorls are slightly nepionic, and shapelessly turgid, but the penultimate and

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 ...

are very well sculptured and defined, being acutely spirally bicarinate. 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 opt ...

is round. The peristome is continuous. It is slightly thickened at the base around the umbilicus. Around the umbilicus, likewise, a third keel, crenulate, and not so acute, revolves. The dark red-brown operculum is multispiral with a not quite central nucleus. A pale straw-coloured

epidermis The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water rele ...

covers the whole surface uniformly.Melvill & Standen (1912), The Marine Mollusca of the Scottish National Antarctic Expedition. Transactions of the Royal Society of Edinburgh. v.48 (1912)
(described as ''Cyclostrema meridionale'')

Distribution

This species occurs in subantarctic waters off the

South Orkney Islands The South Orkney Islands are a group of islands in the Southern Ocean, about north-east of the tip of the Antarctic Peninsula South Shetland Islands The South Shetland Islands are a group of Antarctic islands with a total area of . They lie about north of the Antarctic Peninsula, and between southwest of the nearest point of the South Orkney Islands. By the Antarctic Treaty of 195 ...

at depths between 16 m and 18 m.

References

External links

World Register of Marine Species
{{Taxonbar, from=Q6935827 meridionalis Gastropods described in 1912