Laonidae is a family of small marine snails belonging to the superfamily Philinoidea,[1][2] though Laonidae and Philinoidea are genetically distinct.[3] They are monophyletic, meaning they are developed from a single ancestor.[4] 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 Loana, A.Adams 1865.[5]

Laonidae
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Heterobranchia
Infraclass: Euthyneura
Superfamily: Philinoidea
Family: Laonidae
Pruvot-Fol, 1954
Synonyms

Laoninae Pruvot-Fol, 1954 (original rank)

Genera:[1]

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 edit

Shell edit

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.[6] The pigmented bands on their shells are not a characteristic of any other family under Philinoidea.[7] Most shells will only grow to a maximum of 10mm.[8] 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.[6]

Locomotion edit

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.[9]

Digestion edit

Digestion involved salivary and digestive glands that release digestive enzymes. These animals have a "non-muscularized" gizzard and lack gizzard plates:[6] 3 hardened plates inside the muscular esophageal crop (or gizzard) to help crush the shells of prey, found in Cephalaspidean gastropods.[10] 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.[11] 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.[7] 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.[12]

Respiration and circulation edit

They have an open circulatory system and a dorsal muscular heart that pumps blood to all tissues.[13]

Reproduction edit

As opithsobranchs, these species are simultaneous hermaphrodites, meaning they have both sets of reproductive organs within one individual at the same time.[14]

Diet edit

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.[15]

Geographic distribution edit

Many species of Laonidae are found on Atlantic coastlines, such as the Eastern United States and Western Europe.[16] 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.[15] Within the water column, species in this family are mostly found in soft-bottoms of sand or mud and sometimes near seagrass or algae.[15]

References edit

  1. ^ a b "Laonidae". www.gbif.org. Retrieved 15 June 2021.
  2. ^ 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
  3. ^ Valdés, Ángel; Cadien, Donald B.; Gosliner, Terrence M. (2016-08-08). "Philinidae, Laonidae and Philinorbidae (Gastropoda: Cephalaspidea: Philinoidea) from the northeastern Pacific Ocean and the Beaufort Sea (Arctic Ocean)". Zootaxa. 4147 (5): 501–537. doi:10.11646/zootaxa.4147.5.1. ISSN 1175-5334. PMID 27515632.
  4. ^ Oskars, Trond R.; Bouchet, Philippe; Malaquias, Manuel António E. (2015-08-01). "A new phylogeny of the Cephalaspidea (Gastropoda: Heterobranchia) based on expanded taxon sampling and gene markers". Molecular Phylogenetics and Evolution. 89: 130–150. doi:10.1016/j.ympev.2015.04.011. hdl:1956/10087. ISSN 1055-7903. PMID 25916189.
  5. ^ "WoRMS - World Register of Marine Species - Laonidae Pruvot-Fol, 1954". www.marinespecies.org. Retrieved 2022-04-25.
  6. ^ a b c Oskars, Trond R.; Bouchet, Philippe; Malaquias, Manuel António E. (2015-08-01). "A new phylogeny of the Cephalaspidea (Gastropoda: Heterobranchia) based on expanded taxon sampling and gene markers". Molecular Phylogenetics and Evolution. 89: 130–150. doi:10.1016/j.ympev.2015.04.011. hdl:1956/10087. ISSN 1055-7903. PMID 25916189.
  7. ^ a b Valdés, Ángel; Cadien, Donald B.; Gosliner, Terrence M. (2016-08-08). "Philinidae, Laonidae and Philinorbidae (Gastropoda: Cephalaspidea: Philinoidea) from the northeastern Pacific Ocean and the Beaufort Sea (Arctic Ocean)". Zootaxa. 4147 (5): 501–537. doi:10.11646/zootaxa.4147.5.1. ISSN 1175-5334. PMID 27515632.
  8. ^ Pruvot-Fol, Alice (1954). Mollusques opisthobranches. Lechevalier. OCLC 310086440.
  9. ^ Iwamoto, Mayuko; Ueyama, Daishin; Kobayashi, Ryo (2014-07-21). "The advantage of mucus for adhesive locomotion in gastropods". Journal of Theoretical Biology. 353: 133–141. Bibcode:2014JThBi.353..133I. doi:10.1016/j.jtbi.2014.02.024. ISSN 0022-5193. PMID 24631870.
  10. ^ Shepelenko, Margarita; Brumfeld, Vlad; Cohen, Sidney R.; Klein, Eugenia; Lubinevsky, Hadas; Addadi, Lia; Weiner, Steve (2015-12-10). "The gizzard plates in the Cephalaspidean gastropod Philine quadripartita: Analysis of structure and function". Quaternary International. Malacological Studies from the Past and Present\: A Special Volume in Honor of Henk K. Mienis. 390: 4–14. Bibcode:2015QuInt.390....4S. doi:10.1016/j.quaint.2015.04.060. ISSN 1040-6182.
  11. ^ Gorb, Stanislav N.; Krings, Wencke (2021-10-15). "Mechanical property gradients of taenioglossan radular teeth are associated with specific function and ecological niche in Paludomidae (Gastropoda: Mollusca)". Acta Biomaterialia. 134: 513–530. doi:10.1016/j.actbio.2021.07.057. ISSN 1742-7061. PMID 34329785. S2CID 236530705.
  12. ^ Gajera, Niyati; Vakani, Bhavik; Kundu, Rahul (2022). "Radular Morphology and Relationship Between Shell Size and Radula Size of Few Dominating Intertidal Gastropod Mollusks of Veraval Coast, Gujarat". Frontiers in Marine Science. 9. doi:10.3389/fmars.2022.657124. ISSN 2296-7745.
  13. ^ Charles F. Sturm; Timothy A. Pearce; Ángel Valdés, eds. (2006). The mollusks: a guide to their study, collection, and preservation. Boca Raton, FL: Universal Publishers. ISBN 1-58112-930-0. OCLC 69028066.
  14. ^ "6. The Planktonic Nudibranchs: Swimming Sea Slugs", Pelagic Snails, Stanford University Press, pp. 214–238, 1989-03-01, doi:10.1515/9781503623088-008, ISBN 978-1-5036-2308-8, S2CID 246181411
  15. ^ a b c Oskars, Trond R.; Bouchet, Philippe; Malaquias, Manuel António E. (2015-08-01). "A new phylogeny of the Cephalaspidea (Gastropoda: Heterobranchia) based on expanded taxon sampling and gene markers". Molecular Phylogenetics and Evolution. 89: 130–150. doi:10.1016/j.ympev.2015.04.011. hdl:1956/10087. ISSN 1055-7903. PMID 25916189.
  16. ^ "Laonidae". www.gbif.org. Retrieved 15 June 2021.

External links edit