''Odostomia'' is the most speciose genus of minute

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 ...

s, pyramidellid

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 ...

mollusks. This genus is placed in the family Pyramidellidae in the subfamily

Odostomiinae Odostomiinae, ''Odostomia'' snails and their allies, is a taxonomic subfamily of minute parasitic sea snails. These are marine heterobranch gastropod mollusks, or micromollusks, in the family Pyramidellidae. Taxonomy The subfamily Odostomiinae h ...

. There are several hundred species in this diverse genus (

Schander Carl Fredrik Christoffer Schander (21 May 1960 – 21 February 2012) was a professor in marine biology at the University of Bergen, Norway. He was also a thematic leader at the Centre of Excellence in Geobiology. His doctoral thesis (1997, Univ ...

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 Pyramidellidae. 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 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.

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 called ...

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

s. 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 ...

is usually large, comprising 50-60% of the total length. The aperture is suboval to ovate with the peristome incomplete behind. There is usually a tooth-like fold on the columella. 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 has ...

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 oysters,

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

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 families ...

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