notaspidea

{{Taxobox

| name = Notaspidea

| image = Pleurobranchaea meckelii.jpg

| image_caption = A live individual of Pleurobranchaea meckelii; the gill (or ctenidium) is visible in this view of the right-hand side of the animal

| regnum = Animalia

| phylum = Mollusca

| classis = Gastropoda

| subclassis = Orthogastropoda (older classification)
Heterobranchia (new classification)

| ordo = Opisthobranchia (older classification)

| subordo = Notaspidea

| subordo_authority = P. Fischer, 1883

}}

Notaspidea, also known as the sidegill slugs, is an artificial grouping of sea slugs which is now split into two unrelated groups, the Umbraculida and the Pleurobranchomorpha.Gofas, S. (2014). Notaspidea. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=1754 on 2015-02-12

Taxonomic history

Notaspidea, also known as the sidegill slugs, was a suborder which included both sea slugs and sea snails or false limpets, marine opisthobranch gastropod molluscs in the subclass Orthogastropoda.

However, in the newer taxonomy of Bouchet & Rocroi (2005), the families Umbraculidae and Tylodinidae belong to the superfamily Umbraculoidea Dall, 1889, part of the clade Umbraculida. Grande et al. (2004) found Umbraculoidea to be a sister clade to the Cephalaspidea (Acteonoidea excluded).{{cite journal |author1=Grande C. |author2=J. Templado |author3=J.L. Cervera |author4=R. Zardoya | title=Phylogenetic relationships among Opisthobranchia (Mollusca, Gastropoda) based on mitochondrial cox1, tmV, and rmL genes| journal=Molecular Phylogenetics and Evolution| year=2004| volume=33| pages=378–388| doi=10.1016/j.ympev.2004.06.008 | pmid=15336672 | issue=2}}

The families Tylodinidae and Umbraculidae have large limpet-like external shells and a small mantle, while the species in the family Pleurobranchidae have a prominent mantle and an internal shell that becomes reduced or is lost in adults.{{cite journal | author=R. Willan| title=Phylogenetic systematics of the Notaspidea (Opisthobranchia) with a reappraisal of families and genera| journal=Am. Malacol. Bull.| year=1987| volume=5| pages=215–241}} Many species produce mantle secretions as a chemical defense against predators {{cite journal |author1=Aldo Spinella |author2=Ernesto Mollo |author3=Enrico Trivellone |author4=Guido Cimino | title=Testudinariol A and B, two unusual triterpenoids from the skin and the mucus of the marine mollusc Pleurobrancus testudinarius.| journal=Tetrahedron|date=December 1997| volume=53| issue=49| pages=16891–16896| doi=10.1016/S0040-4020(97)10124-7| doi-access=free}}

Families

Pleurobranchidae Menke, 1828
Tylodinidae Gray, 1847
Umbraculidae Dall, 1889

Notes

References

{{ITIS |id=78119 |taxon=Notaspidea}}
Powell A. W. B., New Zealand Mollusca, William Collins Publishers Ltd, Auckland, New Zealand 1979 {{ISBN|0-00-216906-1}}

Category:Obsolete gastropod taxa