''Odostomia'' is the most speciose

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

of minute sea snails, pyramidellid 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 ...

s. This genus is placed 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 ...

Pyramidellidae Pyramidellidae, common name the pyram family, or pyramid shells, is a voluminous taxonomic family of mostly small and minute ectoparasitic sea snails, marine heterobranch gastropod molluscs. The great majority of species of pyrams are micr ...

in the subfamily Odostomiinae. There are several hundred species in this diverse genus ( Schander et al. 1999) Bouchet, P.; Gofas, S. (2011). Odostomia Fleming, 1813. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=138413 on 3 June 2012 Most of the description of species in the genus ''Odostomia'' was carried out by Dall & Bartsch in 1909. Many of the described species are however suspected of being synonyms, or are proven synonyms. The genus ''Odostomia'' Fleming, 1813 was used by 19th century authors, particularly in the European literature, for most of the smaller

. It is still a catchall for most small pyramidellids lacking both axial and spiral sculpture. Some authors, e.g. Høisæter (2014), Peñas, Rolán & Swinnen (2014) and Giannuzzi-Savelli et al. (2014) who are here followed have attempted to redistribute some of the species, but there are still many species remaining unduly under ''Odostomia''. For these, the database

WoRMS Worms may refer to: *Worm, an invertebrate animal with a tube-like body and no limbs Places *Worms, Germany, a city ** Worms (electoral district) * Worms, Nebraska, U.S. *Worms im Veltlintal, the German name for Bormio, Italy Arts and entertai ...

has refrained from making new combinations not backed by (or implicit from) a published source but, unless otherwise noted, the species that were already "accepted" under a subgenus now raised to full genus have been marked as "accepted" under that full genus. The European and American species of ''Odostomia'' differ in several anatomical and shell characteristics. They are therefore likely to be assigned to different genera.

Distribution

The genus ''Odostomia'' is common in all oceans from the tropics to the polar regions. It is mainly known from coastal areas and sandy shores, and is less common in the

deep sea The deep sea is broadly defined as the ocean depth where light begins to fade, at an approximate depth of 200 metres (656 feet) or the point of transition from continental shelves to continental slopes. Conditions within the deep sea are a combin ...

Description

There is little known about their life histories. Most species are only known from their shells. Most species have a white of yellowish, minute, conical to ovate-conical shell, usually between 2 mm and 5 mm. The apex is rather obtuse or nipple-shaped, sinistrally or dextrally oriented to the teloconch. 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 ...

is usually deeply immersed in the first of the succeeding turns. The shells are variously sculptured, usually with a microsculpture. The

teleoconch The gastropod shell is part of the body of a gastropod or snail, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium storage. So ...

contains in most cases between 4 and 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. The body whorl is usually large, comprising 50-60% of the total length. 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 ...

is suboval to ovate with the

peristome Peristome (from the Greek ''peri'', meaning 'around' or 'about', and ''stoma'', 'mouth') is an anatomical feature that surrounds an opening to an organ or structure. Some plants, fungi, and shelled gastropods have peristomes. In mosses In mosses, ...

incomplete behind. There is usually a tooth-like fold on 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 ...

. The shells usually have a small umbilicus or none at all.

Life habits

The members of ''Odostomia'' are

ectoparasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson ha ...

s on other molluscs, and polychaetes. First they pierce the body wall with the buccal stylet and then feed on them by sucking blood with their buccal pump. They have become a pest of

oyster Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but not a ...

mussel Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, whic ...

scallop Scallop () is a common name that encompasses various species of marine bivalve mollusks in the taxonomic family Pectinidae, the scallops. However, the common name "scallop" is also sometimes applied to species in other closely related familie ...

s and

slipper limpet The Calyptraeidae are a family of small to medium-sized marine prosobranch gastropods. MolluscaBase. Calyptraeidae Lamarck, 1809. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=141 o ...

s. Most of the Odostomia species are host-specific, only a few are not. ''Odostomia scalaris'' MacGillivray, 1843 is an ectoparasite on a wide range of hosts but especially known as a pest of mussels. ''Odostomia turrita'' Hanley, 1844 has been found on the European lobster ''Homarus gammarus'' (Linnaeus, 1758).Sneli, J.-A. (1972). Odostomia turrita found on Homarus gammarus Nautilus: Maandblad van het Koninklijk Belgisch Zeemanscollege = Nautilus: Revue mensuelle du Collège Royal Maritime Belge 86(1): 23

Species

References

* * * Fretter, V. M., and A. Graham. 1949. The structure and mode of life of the Pyramidellidae, parasitic opisthobranchs. J. Mar. Biol. Assoc. U.K. 28: 493-532 * Boss, K. J., and A. S. Merrill. 1965. Degree of host specificity in two species of ''Odostomia'' (Pyramidellidae: Gastropoda). Proc. Malacol. Sot. London 36: 349–355. * Vaught, K.C. (1989). ''A classification of the living Mollusca''. American Malacologists: Melbourne, FL (USA). . XII, 195 pp * Gofas, S.; Le Renard, J.; Bouchet, P. (2001). Mollusca, in: Costello, M.J. et al. (Ed.) (2001). ''European register of marine species: a check-list of the marine species in Europe and a bibliography of guides to their identification''. Collection Patrimoines Naturels, 50: pp. 180–213 * Spencer, H.; Marshall. B. (2009). ''All Mollusca except Opisthobranchia''. In: Gordon, D. (Ed.) (2009). New Zealand Inventory of Biodiversity. Volume One: Kingdom Animalia. 584 pp

External links

To Discoverlife

To GenBank

To ITIS

To World Register of Marine Species
{{Use dmy dates, date=May 2017 Pyramidellidae