''Iothia emarginuloides'' 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 sea snail, a true limpet, 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 e ...

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 ...

Lepetidae Lepetidae is a family of sea snails or small, deep-water true limpets, marine gastropod molluscs in the clade Patellogastropoda the true limpets. Taxonomy This family consists of the two following subfamilies (according to the taxonomy ...

, one of the families of true limpets. This species was previously known as ''Iothia coppingeri''.

Taxonomy

The type specimens of ''I. emarginuloides'' (Philippi, 1868) and ''I. coppingeri'' (E.A. Smith, 1881) are very similar in

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines * Morphology (archaeology), study of the shapes or forms of artifacts * Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies ...

, and were collected only apart; as long ago as 1908 this led to the recognition that they were probably the same species. Despite this, they continued to be treated as two separate species until 2011, when Nakano et al. researched the genus and brought them into

synonymy A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

. ''I. emarginuloides'' was described before ''I. coppingeri'', so by the rules of zoological nomenclature, the earlier name took priority.

Description

''I. emarginuloides'' is a small, broadly ovate, cap-shaped limpet, with a length of about and width of . The apex of the shell is towards the anterior end, and is rather acute, but does not curl over. The shell is thin, and has fine sculptured lines radiating from the apex which formed the basis for the species' descriptive name, ''emarginuloides'', "as if minutely emarginate, or finely notched". There are also irregular, concentric growth rings. The margin is smooth apart from the fine crenelations produced by the radial sculpture. The shell is a "dirty white" colour, with a few greyish concentric bands. Although limpets in the family

are commonly known as "blind limpets", both this species and the closely related '' Iothia fulva'' have small, black-pigmented eyes, situated close to the base of the tentacles.

Distribution

''I. emarginuloides'' is known from Antarctica (the

Weddell Sea The Weddell Sea is part of the Southern Ocean and contains the Weddell Gyre. Its land boundaries are defined by the bay formed from the coasts of Coats Land and the Antarctic Peninsula. The easternmost point is Cape Norvegia at Princess Martha ...

) and southern Chile. Its distribution is probably circum-Antarctic, with its known range extending from the Kerguelen Islands to the Strait of Magellan area. All records are from water shallower than . It is the commonest animal found living on the red alga '' Phyllophora antarctica'' under the sea ice in the vicinity of the

Vestfold Hills The Vestfold Hills are rounded, rocky, coastal hills, in extent, on the north side of Sorsdal Glacier on the Ingrid Christensen Coast of Princess Elizabeth Land, Antarctica. The hills are subdivided by three west-trending peninsulas bounded by n ...

, Antarctica.

References

* Linse K. (2002). The shelled Magellanic Mollusca: with special reference to biogeography relations in the Southern Ocean. Theses Zoologicae. 34: 1–252 * Warén A., Nakano T. & Sellanes J. (2011) A new species of Iothia (Gastropoda: Lepetidae) from Chilean methane seeps, with comments on the accompanying gastropod fauna. The Nautilus 125(1): 1-14 * Engl, W. (2012). Shells of Antarctica. Hackenheim: Conchbooks. 402 pp. * Güller M. & Zelaya D.G. (2016). Species of Iothia (Gastropoda: Lepetidae) from shallow waters of the Magellan Region. Malacologia. 59(2): 321–330.

External links

{{Taxonbar, from=Q13367694 Lepetidae Gastropods described in 1868 Taxa named by Rodolfo Amando Philippi