Megathura crenulata: Difference between revisions

'''''Megathura crenulata''''' is a northeastern [[Pacific Ocean]] species of [[limpet]] in the family [[Fissurellidae]]<ref name=worms>Rosenberg, G. (2015). [http://www.marinespecies.org/aphia.php?p=taxdetails&id=527885 ''Megathura crenulata'' (Sowerby I, 1825).] ''In'': MolluscaBase (2015). Accessed through: World Register of Marine Species on 16 February 2016.</ref> known commonly as the '''great keyhole limpet'''<ref name=hardy>[http://www.gastropods.com/2/Shell_4152.shtml ''Megathura crenulata''.] Hardy's Internet Guide to Marine Gastropods.</ref> or '''giant keyhole limpet'''.<ref name=slb>[http://www.sealifebase.org/summary/Megathura-crenulata.html ''Megathura crenulata''.] SeaLifeBase.</ref> ''Megathura'' is a monotypic genus; in other words, this is the only species in that genus. This species occurs along the rocky coast of western North America, its distribution extending from [[Southern California]] to the [[Baja California peninsula]] in [[Mexico]]. It is found in the [[intertidal zone]] and in the sea up to a depth of 33 meters.<ref name=slb/>

Limpets of this family have a hole at the top of the shell, the portal through which waste products are released. This makes them different from the [[Patellogastropoda|true limpets]], which release waste from the mantle beneath the shell. This species is one of the largest keyhole limpets. <ref>[http://shells.tricity.wsu.edu/ArcherdShellCollection/Gastropoda/Fissurellidae.html Family: Fissurellidae (Keyhole Limpets).] Gladys Archerd Shell Collection, Washington State University Tri-Cities Natural History Museum.</ref>

This species consumes a varied diet of plant, animal, protist, and algal material. It has been noted to consume filamentous [[cyanobacteria]], [[diatom]]s, [[brown algae|brown]] and [[red algae]]s such as [[seaweed]]s, [[seagrass]], [[foraminifera|forams]], [[hydrozoa]]ns, [[bryozoa]]ns, [[nematode]]s, [[bivalvia|bivalves]], [[gastropoda|gastropods]], [[crustacean]]s, and [[tunicate]]s. The larger part of its diet is composed of brown and red algae, tunicates, hydrozoans of the genus ''[[Eudendrium]]'' and bryozoans of the genus ''[[Crisia]]''.<ref>Mazariegos-Villarreal, A., et al. (2013). [http://www.bioone.org/doi/abs/10.2983/035.032.0208 Diet of the keyhole limpet ''Megathura crenulata'' (Mollusca: Gastropoda) in subtropical rocky reefs.] ''Journal of Shellfish Research'', 32(2), 297-303297–303.</ref>

{{mainMain|Keyhole limpet hemocyanin}}

[[Keyhole limpet hemocyanin]] from ''Megathura crenulata'' is used as [[vaccine]] [[carrier protein]]. Keyhole limpet hemocyanin (KLH) is a copper containing respiratory protein, similar to hemoglobin in humans. KLH is a large protein that acts as the hapten carrier part of the vaccine component, and is so far thought to be non-toxic. The major potential use of KLH is for bladder carcinoma by stimulating a specific immune response, but there are many other medical uses such as stress assessment, understanding inflammatory conditions, and treating drug addiction. Vaccines and other KLH uses are in the research or trial phases. A liter of blood from a keyhole limpet will produce 20 grams of protein, which can be worth as much as $100,000.<ref>Harris, J. R. & Markl, J. (1999). [http://www.upch.edu.pe/facien/fc/dbmbqf/zimic/cursos/modelamiento%202005/articulos/25%20Proteinas%20de%20fusi%C3%B3n%20y%20vacunas/KHL%20sdarticle.pdf Keyhole limpet hemocyanin (KLH): a biomedical review.] {{webarchive|url=https://web.archive.org/web/20160224121918/http://www.upch.edu.pe/facien/fc/dbmbqf/zimic/cursos/modelamiento%202005/articulos/25%20Proteinas%20de%20fusi%C3%B3n%20y%20vacunas/KHL%20sdarticle.pdf |date=2016-02-24 }} ''Micron'', 30(6), 597-623597–623.</ref><ref>Sommer, L. [httphttps://spectrum.ieee.org/podcast/biomedical/devices/harvesting-blood-from-limpets-for-a-cancer-vaccine Harvesting blood from limpets for a cancer vaccine.] ''IEEE Spectrum'' 28 September 2012.</ref><ref>Roudman, S. [http://www.popsci.com/science/article/2011-11/how-mollusk-blood-could-cause-cancer How mollusk blood could cure cancer.] ''Popular Science'' 30 December 2011.</ref>

{{commonscatReflist}}

*Beninger, P. G., et al. (2001). [https://archive.org/stream/cbarchive_41113_reproductivecharacteristicsoft1981/reproductivecharacteristicsoft1981#page/n1/mode/2up Reproductive characteristics of the archaeogastropod ''Megathura crenulata''.] ''Journal of Shellfish Research'', 20(1), 301-307301–307.