Laonidae

{{Short description|Family of snails}} {{Automatic taxobox |image = |image_caption = |taxon = Laonidae |authority = Pruvot-Fol, 1954 |synonyms= Laoninae Pruvot-Fol, 1954 (original rank) |display_parents= 3 }}

'''Laonidae''' is a family of small marine snails belonging to the superfamily Philinoidea,<ref name="GBIF2">{{cite web |title=Laonidae |url=https://www.gbif.org/species/8103756 |access-date=15 June 2021 |website=www.gbif.org |language=en}}</ref><ref name="WoRMS2">MolluscaBase eds. (2021). MolluscaBase. Laonidae Pruvot-Fol, 1954. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=848158 on 2021-06-17</ref> though Laonidae and Philinoidea are genetically distinct.<ref name=":0">{{Cite journal |last1=Valdés |first1=Ángel |last2=Cadien |first2=Donald B. |last3=Gosliner |first3=Terrence M. |date=2016-08-08 |title=Philinidae, Laonidae and Philinorbidae (Gastropoda: Cephalaspidea: Philinoidea) from the northeastern Pacific Ocean and the Beaufort Sea (Arctic Ocean) |journal=Zootaxa |volume=4147 |issue=5 |pages=501–537 |doi=10.11646/zootaxa.4147.5.1 |pmid=27515632 |issn=1175-5334}}</ref> They are monophyletic, meaning they are developed from a single ancestor.<ref name=":1">{{Cite journal |last1=Oskars |first1=Trond R. |last2=Bouchet |first2=Philippe |last3=Malaquias |first3=Manuel António E. |date=2015-08-01 |title=A new phylogeny of the Cephalaspidea (Gastropoda: Heterobranchia) based on expanded taxon sampling and gene markers |journal=Molecular Phylogenetics and Evolution |language=en |volume=89 |pages=130–150 |doi=10.1016/j.ympev.2015.04.011 |doi-access=free |pmid=25916189 |issn=1055-7903|hdl=1956/10087 |hdl-access=free }}</ref> Laonidae also has the synonymised name Laoninae, which is largely unaccepted in the modern day scientific community. The name Laoninae is introduced by Alice Pruvot-Fol who proposes it as the subfamily to the genea Laona, A.Adams 1865.<ref>{{Cite web |title=WoRMS - World Register of Marine Species - Laonidae Pruvot-Fol, 1954 |url=https://www.marinespecies.org/aphia.php?p=taxdetails&id=848158 |access-date=2022-04-25 |website=www.marinespecies.org |language=en}}</ref>

Genera:<ref name="GBIF2" />

* ''Laona'' A.Adams, 1865 * ''Retusophiline'' Nordsieck, 1972

; Genera brought into synonymy

* ''Ossiania'' Monterosato, 1884: synonym of ''Laona'' A. Adams, 1865 * ''Praephiline'' Chaban & Soldatenko, 2009: synonym of ''Laona'' A. Adams, 1865 * ''Rhinodiaphana'' Lemche, 1967: synonym of ''Laona'' A. Adams, 1865 * ''Utriculopsis'' M. Sars, 1870: synonym of ''Laona'' A. Adams, 1865

== Anatomy ==

=== Shell === Most species of Laonidae have umbilicated shells with a net-like pattern or smooth surface. The only exception to this is the species P. quadrata. This species has a non-umbilicated, quadrangular shell with chain-like spiral lines.<ref name=":12">{{Cite journal |last1=Oskars |first1=Trond R. |last2=Bouchet |first2=Philippe |last3=Malaquias |first3=Manuel António E. |date=2015-08-01 |title=A new phylogeny of the Cephalaspidea (Gastropoda: Heterobranchia) based on expanded taxon sampling and gene markers |journal=Molecular Phylogenetics and Evolution |language=en |volume=89 |pages=130–150 |doi=10.1016/j.ympev.2015.04.011 |doi-access=free |pmid=25916189 |issn=1055-7903|hdl=1956/10087 |hdl-access=free }}</ref> The pigmented bands on their shells are not a characteristic of any other family under Philinoidea.<ref name=":02">{{Cite journal |last1=Valdés |first1=Ángel |last2=Cadien |first2=Donald B. |last3=Gosliner |first3=Terrence M. |date=2016-08-08 |title=Philinidae, Laonidae and Philinorbidae (Gastropoda: Cephalaspidea: Philinoidea) from the northeastern Pacific Ocean and the Beaufort Sea (Arctic Ocean) |journal=Zootaxa |volume=4147 |issue=5 |pages=501–537 |doi=10.11646/zootaxa.4147.5.1 |pmid=27515632 |issn=1175-5334}}</ref> Most shells will only grow to a maximum of 10mm.<ref>{{Cite book |first=Alice |last=Pruvot-Fol |title=Mollusques opisthobranches |date=1954 |publisher=Lechevalier |oclc=310086440}}</ref> Like other sea snails, animals in the Laonidae family have calcareous shells secreted by a mantle which covers the body. Laonidae specifically have a parietal wall extending into the posterior of their shell aperture.<ref name=":12" />

=== Locomotion === A ventral muscular foot aids in locomotion by using periodic muscular waves along the foot to move the animals across a surface. These waves attach to the substrate with a thin layer of pedal mucus. The adhesion provided by the mucus is the key to Gastropod locomotion.<ref>{{Cite journal |last1=Iwamoto |first1=Mayuko |last2=Ueyama |first2=Daishin |last3=Kobayashi |first3=Ryo |date=2014-07-21 |title=The advantage of mucus for adhesive locomotion in gastropods |journal=Journal of Theoretical Biology |language=en |volume=353 |pages=133–141 |doi=10.1016/j.jtbi.2014.02.024 |issn=0022-5193|doi-access=free |pmid=24631870 |bibcode=2014JThBi.353..133I }}</ref>

=== Digestion === Digestion involved salivary and digestive glands that release digestive enzymes. These animals have a "non-muscularized" gizzard and lack gizzard plates:<ref name=":12" /> 3 hardened plates inside the muscular esophageal crop (or gizzard) to help crush the shells of prey, found in Cephalaspidean gastropods.<ref>{{Cite journal |last1=Shepelenko |first1=Margarita |last2=Brumfeld |first2=Vlad |last3=Cohen |first3=Sidney R. |last4=Klein |first4=Eugenia |last5=Lubinevsky |first5=Hadas |last6=Addadi |first6=Lia |last7=Weiner |first7=Steve |date=2015-12-10 |title=The gizzard plates in the Cephalaspidean gastropod Philine quadripartita: Analysis of structure and function |journal=Quaternary International |series=Malacological Studies from the Past and Present\: A Special Volume in Honor of Henk K. Mienis |language=en |volume=390 |pages=4–14 |doi=10.1016/j.quaint.2015.04.060 |bibcode=2015QuInt.390....4S |issn=1040-6182}}</ref> In order to feed, Laonidae have a ribbon of small, chitinous teeth, otherwise known as a radula. The teeth are attached to a membrane pulled across a surface by inner mouth muscles. The teeth attach to that membrane then tears through the algae or seaweed on that surface and it is then brought into the mouth.<ref>{{Cite journal |last1=Gorb |first1=Stanislav N. |last2=Krings |first2=Wencke |date=2021-10-15 |title=Mechanical property gradients of taenioglossan radular teeth are associated with specific function and ecological niche in Paludomidae (Gastropoda: Mollusca) |journal=Acta Biomaterialia |language=en |volume=134 |pages=513–530 |doi=10.1016/j.actbio.2021.07.057 |pmid=34329785 |s2cid=236530705 |issn=1742-7061}}</ref> Their radula is used for a herbivorous diet, specialized to remove algae and slice seaweed. They have a 6.1.0.1.6 radular formula.<ref name=":02" /> According to the common radula formula, this means the radula has 6 marginal teeth and 1 lateral tooth on each side, and no rachidian or central tooth.<ref>{{Cite journal |last1=Gajera |first1=Niyati |last2=Vakani |first2=Bhavik |last3=Kundu |first3=Rahul |date=2022 |title=Radular Morphology and Relationship Between Shell Size and Radula Size of Few Dominating Intertidal Gastropod Mollusks of Veraval Coast, Gujarat |journal=Frontiers in Marine Science |volume=9 |doi=10.3389/fmars.2022.657124 |doi-access=free |issn=2296-7745}}</ref>

=== Respiration and circulation === They have an open circulatory system and a dorsal muscular heart that pumps blood to all tissues.<ref>{{Cite book |title=The mollusks: a guide to their study, collection, and preservation |date=2006 |publisher=Universal Publishers |editor=Charles F. Sturm |editor2=Timothy A. Pearce |editor3=Ángel Valdés |isbn=1-58112-930-0 |location=Boca Raton, FL |oclc=69028066}}</ref>

=== Reproduction === As opithsobranchs, these species are simultaneous hermaphrodites, meaning they have both sets of reproductive organs within one individual at the same time.<ref>{{Citation |title=6. The Planktonic Nudibranchs: Swimming Sea Slugs |date=1989-03-01 |doi=10.1515/9781503623088-008 |work=Pelagic Snails |pages=214–238 |publisher=Stanford University Press|isbn=978-1-5036-2308-8 |s2cid=246181411 }}</ref>

== Diet == Within the clade Cephalaspidea, there are both herbivorous and carnivorous diets. However, due to the small size of species in Laonidae, their diet most likely consists of diatoms, filamentous algae, and foraminiferans.<ref name=":13">{{Cite journal |last1=Oskars |first1=Trond R. |last2=Bouchet |first2=Philippe |last3=Malaquias |first3=Manuel António E. |date=2015-08-01 |title=A new phylogeny of the Cephalaspidea (Gastropoda: Heterobranchia) based on expanded taxon sampling and gene markers |journal=Molecular Phylogenetics and Evolution |language=en |volume=89 |pages=130–150 |doi=10.1016/j.ympev.2015.04.011 |doi-access=free |pmid=25916189 |issn=1055-7903|hdl=1956/10087 |hdl-access=free }}</ref>

== Geographic distribution == Many species of Laonidae are found on Atlantic coastlines, such as the Eastern United States and Western Europe.<ref name="GBIF3">{{cite web |title=Laonidae |url=https://www.gbif.org/species/8103756 |access-date=15 June 2021 |website=www.gbif.org |language=en}}</ref> A few species are found on the Northern California coast, like the Philine californica Willett, 1944 recently proven to be part of Laonidae. Species in the family Laonidae are typically found in shallow tropical and temperate waters, however they can be very diverse in cold waters.<ref name=":13" /> Within the water column, species in this family are mostly found in soft-bottoms of sand or mud and sometimes near seagrass or algae.<ref name=":13" />

==References== {{Reflist}}

==External links== * [https://doi.org/10.1016/j.ympev.2015.04.011 Oskars T.R., Bouchet P. & Malaquias M.A. (2015). A new phylogeny of the Cephalaspidea (Gastropoda: Heterobranchia) based on expanded taxon sampling and gene markers. Molecular Phylogenetics and Evolution. 89: 130-150]

Category:Cephalaspidea Category:Taxa named by Alice Pruvot-Fol