Vetigastropoda
| Vetigastropoda Temporal range:
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| Variousshellsof Vetigastropoda | |
Scientific classification
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Subclass: | Vetigastropoda Salvini-Plawen, 1989 |
| Superfamilies | |
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See text | |
| Diversity[2] | |
| 3,700 extant species | |
Vetigastropodais a majortaxonomicgroup ofsea snails,marinegastropodmollusksthat form a very ancientlineage.Taxonomically the Vetigastropoda are sometimes treated as anorder,although they are treated as an unrankedcladeinBouchet and Rocroi, 2005.
Vetigastropods are considered to be among the most primitive living gastropods,[3]and are widely distributed in alloceansof the world. Their habitats range from thedeep seatointertidal zones.Many haveshellswith slits or other secondary openings. One of their main characteristics is the presence of intersected crossed platy shell structure.[4]Most vetigastropods have some bilateral asymmetry of theirorgansystems.[5]
Description
[edit]Vetigastropods range in size from approximately 0.08 in (2 mm) long in the case ofScissurelloideaorSkeneoidea,to more than 11.8 in (300 mm) in length, as with theHaliotoidea.External colours and patterns are typically drab, but such groups as theTricolioideaand someTrochoideaandPleurotomarioideahave bright colours and glossy shells. The clade is characterized by having an intersected crossed platy shell structure.[4]
Shells range from elongate turret-shaped structures, to near-spherical. Shell sculpture varies greatly from simple concentric growth lines, which may or may not be barely visible on the shell surface, to heavy radial and axial ribbing. The shell aperture is normally oval, and often tangential to the coiling axis. Most species have anoperculum(a small lid-like organ). Within the shell, Vetigastropods have a single pair of cephalic tentacles, and a distinct snout containing the mouth. The lateral sides of the body typically have sensory epipodial tentacles.[6]
Distribution
[edit]Vetigastropods are found throughout all oceans of the world from shallow coastal waters to deep-sea environments, includingtropicalareas, temperate regions, and underpolar ice.
Habitat
[edit]Vetigastropods are present in most marine environments from intertidal zones to the deep sea. Many vetigastropods have adapted to specific ecological niches within their marine environments. They exist on rocky substrates, in soft sediments, and some have been found at deep-seahydrothermal ventsand cold seeps.
Behaviour
[edit]Most vetigastropods aredioecious,although some deep-sea varieties arehermaphrodites.Vetigastropods usually eject their gametes directly into the sea for fertilization, thus there is no courtship or mating between individuals for most species.
Diet
[edit]Vetigastropods typically feed on such organisms asbryozoans,tunicates,andsponges.Several species such asHaliotoideaandTrochoideahave evolved to feed directly on such plant material asalgaeand marineangiosperms.Deep-sea vetigastropods typically consume sediment.[7]
Reproduction
[edit]Vetigastropods typically have separate sexes, with individuals being either male or female. Fertilization usually occurs externally, and they lay eggs that develop into free-swimming larvae before settling as young adults. They normally have very small eggs that producelecithotrophic(yolk feeding) or non-feedinglarvae.Many vetigastropods secreteeggenvelopes and have glandular pallial structures that produce masses of jelly-coated eggs.
Larger species typically have yearly cycles of spawning, and produce millions of eggs per reproductive season. Smaller species produce fewer eggs, but can spawn year round.
Taxonomy
[edit]The Vetigastropoda have been referred to as a superorder as recently as at least 2007, by M. Harzhauser[8]and in 2005 by D. Heidelberger and L. Koch[9]followingPonder & Lindberg, 1997,althoughBouchet & Rocroi, 2005refer to this group simply as a clade, leaving taxonomic determination as a future option. The World Register of Marine Species (WoRMS) follows Bouchet & Rocroi regarding the taxonomic content of the Gastropoda but gives ranks to the higher taxa and defines Vetigastropoda as a subclass.[10]
Bouchet & Rocroi, 2005treats the Vetigastropoda as a major clade and as a sister clade to theCaenogastropodabut includes the Vetigastropoda in what are referred to as Basal taxa that are certainly Gastropoda. Ponder & Lindberg, 1997 previously assigned the Vetigastropoda, as a superorder, to the SubclassOrthogastropoda.Phylogeneticanalysis indicates that thistaxonis one of the four natural groups within the Gastropoda: Vetigastropoda,Caenogastropoda,Patellogastropoda,andHeterobranchia.Research on themitochondrialgenomearrangement has shown that the Vetigastropoda (and Caenogastropoda) mostly retain the ancestralgenearrangement.[11]
Superfamilies
[edit]Superfamilies within the Vetigastropoda include:
- Not assigned to a superfamily within Vetigastropoda are:
- the families:AtaphridaeCossmann, 1915,PendromidaeWarén, 1991(synonym: TrachysmatidaeThiele, 1925), †Schizogoniidae
- the genera:SahlingiaWarén & Bouchet, 2001
- Superfamily †Amberleyoidea
- SuperfamilyAngarioidea(created as a new superfamily by Williams et al. (2008).[12])
- Superfamily †Eotomarioidea
- SuperfamilyFissurelloideaFlemming, 1822- keyhole limpets
- SuperfamilyHaliotoideaRafinesque,1815- abalones[13]
- SuperfamilyLepetelloidea
- SuperfamilyLepetodriloideaMcLean, 1988- hydrothermal vent limpets
- Superfamily †Murchisonioidea
- SuperfamilyNeomphaloidea:belongs in its own independent clade, the Neomphalina, outside the Vetigastropoda[14]
- SuperfamilyPleurotomarioideaSwainson,1840- slit snails: a sister clade to Neomphalina[14]
- Superfamily †Porcellioidea
- SuperfamilyScissurelloidea
- SuperfamilySeguenzioideaVerrill, 1884
- SuperfamilyTrochoideaRafinesque,1815- top snails
- SuperfamilyTurbinoidea- turban snails - In 2008 this superfamily has been split into Trochoidea and Phasianelloidea
References
[edit]- ^Frýda, Jiří (1997). "Oldest Representatives of the Superfamily Cirroidea (Vetigastropoda) with Notes on Early Phylogeny".Journal of Paleontology.71(5): 839–847.doi:10.1017/s0022336000035782.JSTOR1306561.S2CID130637321.
- ^Geiger, D.L.; Nützel, A.; Sasaki, T. (2008). "Vetigastropoda". In Ponder, W.F.; Lindberg, D.R. (eds.).Phylogeny and evolution of the Mollusca.University of California Press. pp. 297–330.ISBN9780520250925.
- ^Robertson, R. (2003)."The edible West Indian" whelk "Cittarium pica(Gastropoda: Trochidae): Natural history with new observations ".Proceedings of the Academy of Natural Sciences of Philadelphia.153(1): 27–47.doi:10.1635/0097-3157(2003)153[0027:TEWIWC]2.0.CO;2.S2CID86363886.
- ^abHedegaard, C. (1997)."Shell structures of the recent Vetigastropoda".Journal of Molluscan Studies.63(3): 369–377.doi:10.1093/mollus/63.3.369.ISSN1464-3766.
- ^Salvini-Plawen, L.; Haszprunar, G. (1987). "The Vetigastropoda and the Systematics of Streptoneurous Gastropoda (Mollusca)".Journal of Zoology (London).211(4): 747–770.doi:10.1111/j.1469-7998.1987.tb04485.x.
- ^Haszprunar, G. (1993). "Sententia: The Archaeogastropoda: A Clade, a Grade, or What Else?".American Malacological Union Bulletin.10:165–177.
- ^Hickman, C. S. (1988). "Archaeogastropod Evolution, Phylogeny and Systematics: A Re-Evaluation".Malacological Review.Supplement 4: 17–34.
- ^Harzhauser, M. (2007)."Oligocene and Aquitanian gastropod faunas from the Sultanate of Oman and their biogeographic implications for the western Indo-Pacific".Palaeontographica Abteilung A.280:75–121.doi:10.1127/pala/280/2007/75.
- ^Heidelberger, D.; Koch, L. (2005)."Gastropoda from the Givetian" Massenkalk "of Schwelm and Hohenlimburg (Saureland, Rheinsiches Schiefergebirge, Germany)".Geologica et Palaeontologica Sonderband.4:1–107.
- ^Gofas, S. (2010). Gastropoda. World Register of Marine Species
- ^Grande C., Templado J. & Zardoya R. (2008)."Evolution of gastropod mitochondrial genome arrangements".BMC Evolutionary Biology.8(1): 61.doi:10.1186/1471-2148-8-61.PMC2291457.PMID18302768.
- ^Williams, S. T.; Karube, S.; Ozawa, T. (2008). "Molecular systematics of Vetigastropoda: Trochidae, Turbinidae and Trochoidea redefined".Zoologica Scripta.37(5): 483–506.doi:10.1111/j.1463-6409.2008.00341.x.S2CID84570997.
- ^taxonomy."ErrorTaxonomy object not found".Ncbi.nlm.nih.gov.Retrieved2013-09-28.
- ^abAktipis, Stephanie W.; Giribet, Gonzalo (2010)."A phylogeny of Vetigastropoda and other" archaeogastropods ": re-organizing old gastropod clades"(PDF).Invertebrate Biology.129(3): 220–240.doi:10.1111/j.1744-7410.2010.00198.x.
External links
[edit]
- Aktipis, S. W.; Giribet, G. (2011)."Testing relationships among the vetigastropod taxa: A molecular approach".Journal of Molluscan Studies.78:12–27.doi:10.1093/mollus/eyr023.
- Herbert D.G. (2015). An annotated catalogue and bibliography of the taxonomy, synonymy and distribution of the Recent Vetigastropoda of South Africa (Mollusca). Zootaxa. 4049(1): 1-98
- Gastropod taxonomy at Palaeos
- Gastropod reproductive behavior
- Gastropod Neuroscience
- Reconstructions of fossil gastropods
- 2004 Linnean taxonomy of gastropods