Pyramidellidae

Taxobox
name = Pyramidellidae


image_width = 240px
image_caption =
regnum = Animalia
phylum = Mollusca
classis = Gastropoda
subclassis = Orthogastropoda
superordo = Heterobranchia
ordo = Heterostropha
superfamilia = Pyramidelloidea
familia = Pyramidellidae
familia_authority = J.E. Gray, 1840
subdivision_ranks = subfamilies
subdivision = See text.

Pyramidellidae, common name the pyram family, or pyramid shells, is a voluminous taxonomic family of mostly small and minute parasitic sea snails, marine heterobranch gastropod molluscs or micromolluscs.

The pyram family comprises more than 6,000 species in more than 350 genera cite journal | author=Schander C.; Halanych K.M.; Dahlgren T.; Sundberg P| title=Test of the monophyly of Odostomiinae and Turbonilliinae (Gastropoda, Heterobranchia, Pyramidellidae) based on 16S mtDNA sequences| journal=Zoologica Scripta| month=May | year=2003| volume=32| issue=3| url=http://www.ingentaconnect.com/content/bsc/zsc/2003/00000032/00000003/art00003| pages=243–254| doi=10.1046/j.1463-6409.2003.00112.x] . This family of micromollusks has been little studied and the phylogenetic relationships within the family are not well worked out. It is currently divided into 11 subfamilies (Ponder & Lindberg 1997). An alternative interpretation is that the family Pyramidellidae is but one of six families within the superfamily Pyramidelloidea (Schander, van Aartsen & Corgan 1999).

ubfamilies in the family Pyramidellidae

Taxonomy of Ponder & Lindberg (1997)

* Chrysallidinae Saurin, 1958
* Cingulininae Saurin, 1959
* Cyclostremellinae Moore, 1966
* Eulimellinae Saurin, 1958
* Odostomellinae Saurin, 1959
* Odostomiinae Pelseneer, 1928
* Pyramidellinae J.E. Gray, 1840
* Sayellinae Wise, 1996
* Syrnolinae Saurin, 1958
* Tiberiinae Saurin, 1958
* Turbonillinae Bronn, 1849

Taxonomy of Schander, Van Aartsen & Corgan (1999)

*Superfamily Pyramidelloidea Gray, 1840
**Family Amathinidae Ponder, 1987
**Family Ebalidae Warén, 1994 = Anisocyclidae van Aartsen, 1995
**Family Odostomiidae Pelseneer, 1928
***Subfamily Odostomiinae Pelseneer, 1928
***Subfamily Chrysallidinae Saurin, 1958
***Subfamily Odostomellinae Saurin, 1958
***Subfamily Cyclostremellinae Moore, 1966
**Family Pyramidellidae J.E. Gray, 1840
***Subfamily Pyramidellinae J.E. Gray, 1840
***Subfamily Sayellinae Wise, 1996
**Family Syrnolidae Saurin, 1958
***Subfamily Syrnolinae Saurin, 1958
***Subfamily Tiberiinae Saurin, 1958
**Family Turbonillidae Bronn, 1849
***Subfamily Turbonillinae Bronn, 1849
***Subfamily Eulimellinae Saurin, 1958
***Subfamily Cingulininae Saurin, 1959

Taxonomy of Bouchet & Rocroi (2005)

*Subfamily Pyramidellinae Gray, 1840
**Tribe Pyramidellini Gray, 1840
**Tribe Sayellini Wise, 1996 (formerly subfamily Sayellinae)
*Subfamily Odostomiinae Pelseneer, 1928
**Tribe Odostomiini Pelseneer, 1928
**Tribe Chrysallidini Saurin, 1958 (formerly subfamily Chrysallidinae)
**Tribe Cyclostremellini D.R. Moore, 1966 (formerly subfamily Cyclostremellinae)
**Tribe Odostomellini Saurin, 1959 (formerly subfamily Odostomellinae)
*Subfamily Syrnolinae Saurin, 1958 (formerly subfamily Syrnolinae)
**Tribe Syrnolini Saurin, 1958
**Tribe Tiberiini Saurin, 1958 (formerly subfamily Tiberiinae)
*Subfamily Turbonillinae Bronn, 1849
**Tribe Turbonillini Bronn, 1849
**Tribe Cingulinini Saurin, 1958 (formerly subfamily Cingulininae)
**Tribe Eulimellini Saurin, 1958 (formerly subfamily Eulimellinae)

Problematic genera

The following genera are currently difficult to place within existing subtaxa of the Pyramidellidae.
* Contraxalia Laseron, 1956
* Cossmannica Dall & Bartsch, 1904
* Eulimotibera Nomura, 1939
* Morrisonetta Brandt, 1968
* Peristicha Dall, 1889
* Ulfa Dall & Bartsch, 1904
* Vagna Dall & Bartsch, 1904

Distribution

This family is found worldwide.

hell description

The shell of these snails has a blunt, heterostrophic protoconch, which is often pointed sideways or wrapped up.

The length of the slender, elongated (turreted or conical) shells varies between 0.5 mm and 3.5 cm, but most species in the family have shells which are smaller than 13 mm.

The texture of these shells is smooth or sculptured in various forms such as ribs and spirals. Their color is mostly white, cream or yellowish, sometimes with red or brown lines.

The teleoconch is coiled, but the larval shells are . This results in a sinistrally coiled protoconch.

The columella has usually one, but sometimes several, spiral folds. The aperture is closed by an operculum.

Life habits

The Pyramidellidae are ectoparasites, feeding mainly on other molluscs and on annelid worms, but some are known to feed on peanut worms and crustaceans (e.g. Sneli, 1972, Robertson & Mau-Lastovicka, 1979).

They do not have a radula. Instead their long proboscis is used to pierce the skin of its prey and suck up its fluids and soft tissues. The eyes on the grooved tentacles are situated toward the base of the tentacles. Between the head and the foot, a lobed process called the mentum ( = thin projection) is visible.

These molluscs are hermaphrodites, laying eggs in jelly-like masses on the shell of its host. Some species have spermatophores (Høisaeter, 1965, Robertson, 1967, Schander, Hori & Lundberg, 1999)

Notes

References

* cite journal
author = Bouchet, P. & Rocroi, J.-P.
year = 2005
date=
title = Classification and Nomenclator of Gastropod Families
journal = Malacologia
volume =47
issue = 1-2
pages = 1–397
issn =
doi =
*cite book
last = Gray
first = J. E.
title = Synopsis of the contents of the British Museum, 42th edition
publisher = London
year = 1840
pages =370 pp
month =
isbn =
* cite journal
author = Høisæter, T.
year = 1965
date=
title = Spermatophores in Chrysallida obtusa (Brown) (Opisthobranchia, Pyramidellidae)
journal = Sarsia
volume =18
issue =
pages = 63–68
issn =
doi =
* cite journal
author = Ponder, W.F. & Lindberg, D. R.
year = 1997
date=
title = Towards a phylogeny of gastropod molluscs: an analysis using morphological characters
journal = Zoological Journal of the Linnean Society
volume =119
issue =
pages = 88–265
issn =
doi =
* cite journal
author = Robertson, R.
year = 1967
date=
title = The life history of Odostomia bisuturalis and Odostomia spermatophores (Gastropoda: Pyramidellidae)
journal =American Philosophical Society Yearbook
volume =1967
issue =
pages = 368–370
issn =
doi =
* cite journal
author = Robertson, R.
year = 1979
date=
title = The ectoparasitism of Boonea and Fargoa (Gastropoda: Pyramidellidae)
journal = Biological Bulletin
volume = 157
issue =
pages = 320–333
issn =
doi =
* cite journal
author = Schander, C., van Aartsen, J. J., Corgan, J. C.
year = 1999
date=
title = Families and genera of the Pyramidelloidea (Mollusca: Gastropoda)
journal = Bollettino Malacologico
volume =34
issue = 9-12
pages = 145–166
issn =
doi =
* cite journal
author = Schander, C., Hori, S., Lundberg, J.
year = 1999
date=
title = Anatomy, Phylogeny and biology of Odostomella and Herviera, with the description of a new species of Odostomella (Mollusca, Heterostropha, Pyramidellidae)
journal = Ophelia
volume =51
issue = 1
pages = 39–76
issn =
doi =
* cite journal
author = Sneli, J.-A.
year = 1972
date=
title = Odostomia turrita found on Hommarus gammarus
journal = Nautilus
volume =86
issue = 1
pages = 23–24
issn =
doi =

External links

*
* Gallery of pyramidellids [http://www.conchology.be/en/availableshells/searchresultsgallery.php?family=pyramidellidae&species=&locality=&size=&operculum=&uniquenumber=&sort_by=family&response=SearchResultsGallery.php&Search=Search]