Plesiocystiscus is a
genus of minute
predatory 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,
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 ...
mollusks or
micromollusk
A micromollusk is a shelled mollusk which is extremely small, even at full adult size. The word is usually, but not exclusively, applied to marine mollusks, although in addition, numerous species of land snails and freshwater mollusks also ...
s in the family
Cystiscidae
Cystiscidae is a taxonomic family of minute sea snails, marine gastropod mollusks or micromollusks.
Description
The shell is minute to large, either white, uniformly colored, or patterned; the surface is smooth, sculptured, or axially costate; ...
.
Etymology
The genus name is derived from the
Greek ''plesios'', near, in the sense of plesiomorphic, of characters near the ancestor, combined with ''Cystiscus'' the name of another closely related genus. This indicates the relationship to the genus ''Cystiscus'', type genus of the family. The gender of the name is masculine.
Taxonomy
Sometimes this
genus is simply left in the larger family
Marginellidae. The type species is ''Marginella jewettii'' Carpenter, 1857.
(Note: Gastropod
taxonomy has been in flux for more than half a century, and this is especially true currently, because of new research in
molecular
A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioche ...
phylogeny. Because of all the ongoing changes, different reliable sources can yield very different classifications).
Shell description
Shell minute to small (adult length 1,5 to 6.0 mm). Color white, hyaline; surface smooth, glossy. Shape cylindrical, elliptic, or obovate; weakly to distinctly shouldered.
Suture rapidly descending on last half of last whorl, then abruptly sweeping upward just before lip, giving characteristic shape to adult shell.
Spire nearly flat to low.
Aperture moderately narrow, broader anteriorly. Lip thin anteriorly, gradually thickening tower shoulder, smooth, lacking denticulation or
lira
Lira is the name of several currency units. It is the current currency of Turkey and also the local name of the currencies of Lebanon and of Syria. It is also the name of several former currencies, including those of Italy, Malta and Israe ...
e, external
varix
A varix (pl. varices) is an abnormally dilated vessel with a tortuous course. Varices usually occur in the venous system, but may also occur in arterial or lymphatic vessels.
Examples of varices include:
* Varicose veins, large tortuous veins usua ...
absent. Siphonal notch and posterior notch absent. Shell often with a weak parietal callus wash or weak parietal callus deposits. Columella multiplicate, with combined total of 3-8 plications, usually occupying less than half to slightly more than half the aperture length. Shell with cystiscid internal
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.
Anatomy
The triserial radula, found in many other cystiscids, is the most primitive in this family. This is the only genus of marginelliform gastropods with a triserial
radula
The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food ...
. This group is considered to be the most primitive in the family based on the radula and type of animal. The radular and shell features, including the presence of odontophoral cartilage hoods, possession of cystiscid internal whorls, and lack of an external varix, place this group in the Cystiscidae.
Ecology
Habitat
This genus lives from the
intertidal zone
The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species o ...
to 80 m in depth.
Fossil record
This genus is found in the
Eocene of
France, the
Miocene and
Pliocene of
Florida, and the
Pleistocene of
California, to the Recent.
Species
Species within the genus ''Plesiocystiscus'' include:
* ''
Plesiocystiscus abbotti''
(de Jong & Coomans, 1988)
* ''
Plesiocystiscus alfiopivai''
Espinosa & Ortea, 2002
* ''
Plesiocystiscus alfredensis
''Plesiocystiscus alfredensis'', common name the blue oval marginella, is a species of very small sea snail, a marine gastropod mollusk in the family Cystiscidae
Cystiscidae is a taxonomic family of minute sea snails, marine gastropod mollu ...
''
(Bartsch, 1915)
* ''
Plesiocystiscus aphanospira
''Plesiocystiscus aphanospira'' is a species of sea snail, a marine gastropod mollusk, in the family Cystiscidae
Cystiscidae is a taxonomic family of minute sea snails, marine gastropod mollusks or micromollusks.
Description
The shell is mi ...
''
(Tomlin, 1913)
* ''
Plesiocystiscus atomus''
(E.A. Smith, 1890)
* ''
Plesiocystiscus bavayi
''Plesiocystiscus bavayi'' is a species of very small sea snail, a marine gastropod mollusc or micromollusc in the family Cystiscidae.
Description
Distribution
This marine species occurs off New Caledonia
)
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''
Boyer, 2003
* ''
Plesiocystiscus bubistae
''Plesiocystiscus bubistae'' is a species of very small sea snail, a marine gastropod mollusk or micromollusk in the family (biology), family Cystiscidae.
Description
The shell size varies between 1.5 mm and 2.3 mm.
Distribution
Thi ...
''
(Fernandes, 1988)
* ''
Plesiocystiscus buzio
Plesiocystiscus is a genus of minute predatory sea snails, marine gastropod mollusks or micromollusks in the family Cystiscidae.
Etymology
The genus name is derived from the Greek ''plesios'', near, in the sense of plesiomorphic, of characte ...
''
Ortea, Moro & Espinosa, 2020
* ''
Plesiocystiscus cinereus''
(Jousseaume, 1875)
* ''
Plesiocystiscus consanguineus
''Plesiocystiscus consanguineus'' is a species of sea snail, a marine gastropod mollusk, in the family Cystiscidae
Cystiscidae is a taxonomic family of minute sea snails, marine gastropod mollusks or micromollusks.
Description
The shell ...
''
(E.A. Smith, 1890)
* ''
Plesiocystiscus elzae
''Plesiocystiscus elzae'' is a species of sea snail, a marine gastropod mollusk, in the family Cystiscidae.MolluscaBase (2018). ''Plesiocystiscus elzae'' Bozzetti, da Costa & T. Cossignani, 2010. Accessed through: World Register of Marine Species ...
''
Bozzetti, Da Costa & T. Cossignani, 2010
* ''
Plesiocystiscus fabioi
Plesiocystiscus is a genus of minute predatory sea snails, marine gastropod mollusks or micromollusks in the family Cystiscidae.
Etymology
The genus name is derived from the Greek ''plesios'', near, in the sense of plesiomorphic, of characte ...
''
T. Cossignani & Lorenz, 2020
* ''
Plesiocystiscus franki''
Espinosa & Ortea, 2019
* ''
Plesiocystiscus genecoani
''Plesiocystiscus genecoani'' is a species of very small sea snail, a marine gastropod mollusc or micromollusc in the family Cystiscidae
Cystiscidae is a taxonomic family of minute sea snails, marine gastropod mollusks or micromollusks.
D ...
''
Espinosa & Ortea, 2000
* ''
Plesiocystiscus gutta''
(Gofas & Fernandes, 1987)
* ''
Plesiocystiscus irinae
''Plesiocystiscus irinae'' is a species of sea snail, a marine gastropod mollusk, in the family Cystiscidae
Cystiscidae is a taxonomic family of minute sea snails, marine gastropod mollusks or micromollusks.
Description
The shell is minu ...
''
Bozzetti, Da Costa & T. Cossignani, 2010
* ''
Plesiocystiscus jansseni''
(de Jong & Coomans, 1988)
* ''
Plesiocystiscus janzeni''
Espinosa & Ortea, 2019
* ''
Plesiocystiscus jardonae''
Ortea & Espinosa, 2016
* ''
Plesiocystiscus jewettii
Plesiocystiscus jewettii is a species of minute predatory sea snail, a marine gastropod mollusk in the family Cystiscidae
Cystiscidae is a taxonomic family of minute sea snails, marine gastropod mollusks or micromollusks.
Description
The s ...
''
(Carpenter, 1857)
* ''
Plesiocystiscus josephinae
''Plesiocystiscus josephinae'' is a species of minute sea snail, a marine gastropod mollusk in the family Cystiscidae.
Distribution
This species is endemic to São Tomé and Príncipe
São Tomé and Príncipe (; pt, São Tomé e Prínci ...
''
(Fernandes & Rolan, 1991)
* ''
Plesiocystiscus larva''
(Bavay, 1922)
* ''
Plesiocystiscus leonorae
''Plesiocystiscus leonorae'' is a species of sea snail, a marine gastropod mollusk, in the family Cystiscidae
Cystiscidae is a taxonomic family of minute sea snails, marine gastropod mollusks or micromollusks.
Description
The shell is mi ...
''
Bozzetti, Da Costa & T. Cossignani, 2010
* ''
Plesiocystiscus luiscarlosi
''Plesiocystiscus luiscarlosi'' is a species of sea snail, a marine gastropod mollusk, in the family Cystiscidae
Cystiscidae is a taxonomic family of minute sea snails, marine gastropod mollusks or micromollusks.
Description
The shell is ...
''
Bozzetti, Da Costa & T. Cossignani, 2010
* ''
Plesiocystiscus luteopunctatus''
Ortea, Moro & Espinosa, 2020
* ''
Plesiocystiscus mariae
''Plesiocystiscus mariae'' is a species of sea snail, a marine (ocean), marine gastropod mollusk, in the family (biology), family Cystiscidae.MolluscaBase (2018). ''Plesiocystiscus mariae'' (Espinosa & Ortea, 2014). Accessed through: World Regist ...
''
(Espinosa & Ortea, 2014)
* ''
Plesiocystiscus mongei
Plesiocystiscus is a genus of minute predatory sea snails, marine gastropod mollusks or micromollusks in the family Cystiscidae.
Etymology
The genus name is derived from the Greek ''plesios'', near, in the sense of plesiomorphic, of characte ...
''
Espinosa & Ortea, 2019
* ''
Plesiocystiscus ovatus
''Plesiocystiscus ovatus'' is a species of very small sea snail, a marine gastropod mollusc or micromollusc in the family Cystiscidae
Cystiscidae is a taxonomic family of minute sea snails, marine gastropod mollusks or micromollusks.
Desc ...
''
Lussi & Smith, 1998
* ''
Plesiocystiscus palantirulus''
(Roth & Coan, 1968)
* ''
Plesiocystiscus politulus
''Plesiocystiscus politulus'' is a species of sea snail, a marine gastropod mollusk, in the family Cystiscidae
Cystiscidae is a taxonomic family of minute sea snails, marine gastropod mollusks or micromollusks.
Description
The shell is m ...
''
( Dall, 1919)
* ''
Plesiocystiscus pseudogranulina''
Lussi & Smith, 1998
* ''
Plesiocystiscus thalia
''Plesiocystiscus thalia'' is a species of sea snail, a marine gastropod mollusk, in the family Cystiscidae.MolluscaBase (2018). ''Plesiocystiscus thalia'' (W. Turton, 1932). Accessed through: World Register of Marine Species at: http://www.ma ...
''
(Turton, 1932)
* ''
Plesiocystiscus tomlini
Plesiocystiscus is a genus of minute predatory sea snails, marine gastropod mollusks or micromollusks in the family Cystiscidae.
Etymology
The genus name is derived from the Greek ''plesios'', near, in the sense of plesiomorphic, of characte ...
''
(Bavay, 1917)
* ''
Plesiocystiscus valae
''Plesiocystiscus valae'' is a species of very small sea snail, a marine gastropod mollusc or micromollusc in the family Cystiscidae
Cystiscidae is a taxonomic family of minute sea snails, marine gastropod mollusks or micromollusks.
Descr ...
''
Lussi & Smith, 1998
* ''
Plesiocystiscus variegatus
''Plesiocystiscus variegatus'' is a species of very small sea snail, a marine gastropod mollusc or micromollusc in the family Cystiscidae
Cystiscidae is a taxonomic family of minute sea snails, marine gastropod mollusks or micromollusks.
De ...
''
Lussi & Smith, 1998
* ''
Plesiocystiscus violaceus''
Rolán E. & Gori S. 2014
* ''
Plesiocystiscus watanuensis''
Cossignani, 2001
;Synonyms:
* ''Plesiocystiscus bocasensis''
(Olsson & McGinty, 1958): synonym of ''Plesiocystiscus larva''
(Bavay, 1922)
References
Footnotes
* Espinosa & Ortea (2000). "Descripción de un género y once especies nuevas de Cystiscidae y Marginellidae (Mollusca: Neogastropoda) del Caribe de Costa Rica". ''Aviccenia'' 12/13: 95-114.
* Espinosa & Ortea (2002). "Nuevas especies de margineliformes de Cuba, Bahamas y el Mar Caribe de Costa Rica". ''Avicennia'' 15: 101-128.
* Bozzetti L., Da Costa D. & Cossignani, T. (2010) ''Quattro nuovi Plesiocystiscus dal Mozambico (Gastropoda: Prosobranchia, Cystiscidae).'' Malacologia Mostra Mondiale 69:16-18.
External links
Coovert G.A. & Coovert H.K. (1995) Revision of the supraspecific classification of marginelliform gastropods. The Nautilus 109(2-3): 43-110
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