Editing Oyster (section)

==Types==

===True oysters===

[[True oyster]]s are members of the family [[Ostreidae]]. This family includes the edible oysters, which mainly belong to the genera ''[[Ostrea]]'', ''[[Crassostrea]]'', ''[[Magallana]]'', and ''[[Saccostrea]]''. Examples include the [[European flat oyster]], [[eastern oyster]], [[Olympia oyster]], [[Pacific oyster]], and the [[Sydney rock oyster]]. Ostreidae evolved in the [[Early Triassic]] [[epoch (geology)|epoch]]: The [[genus]] ''[[Liostrea]]'' grew on the shells of living [[ammonoids]].<ref>{{cite journal | url=https://academic.oup.com/mollus/article/83/3/253/3862014 | doi=10.1093/mollus/eyx018 | title=Geologically oldest oysters were epizoans on Early Triassic ammonoids | year=2017 | last1=Hautmann | first1=Michael | last2=Ware | first2=David | last3=Bucher | first3=Hugo | journal=Journal of Molluscan Studies | volume=83 | issue=3 | pages=253–260 | doi-access=free }}</ref>

===Pearl oysters===

[[File:Pearl Oysters.jpg|thumb|right|Removing a [[pearl]] from a pearl oyster|alt=Photo of opened oyster in bowl with person using a knife to remove the pearl]]
{{Main|Pearl oyster}}
Almost all shell-bearing mollusks can secrete pearls, yet most are not very valuable. Pearls can form in both saltwater and freshwater environments.

[[Pearl oyster]]s are not closely related to true oysters, being members of a distinct family, the feathered oysters ([[Pteriidae]]). Both [[cultured pearl]]s and [[natural pearl]]s can be extracted from pearl oysters, though other molluscs, such as the freshwater [[mussel]]s, also yield pearls of commercial value.

The largest pearl-bearing oyster is the marine ''Pinctada maxima'', which is roughly the size of a dinner plate. Not all individual oysters produce pearls.

In nature, pearl oysters produce pearls by covering a minute invasive object with [[nacre]]. Over the years, the irritating object is covered with enough layers of nacre to become a pearl. The many different types, colours and shapes of pearls depend on the natural [[pigment]] of the nacre, and the shape of the original irritant.

Pearl farmers can culture a pearl by placing a nucleus, usually a piece of polished mussel shell, inside the oyster. In three to seven years, the oyster can produce a perfect pearl. Since the beginning of the 20th century, when several researchers discovered how to produce artificial pearls, the cultured pearl market has far outgrown the natural pearl market.<ref>{{cite journal |title       = A History of the Cultured Pearl Industry
 |year = 2013
 |publisher   = [[BioOne]]
 |doi = 10.2108/zsj.30.783
 |last1 = Nagai
 |first1 = Kiyohito
 |journal = Zoological Science
 |volume = 30
 |issue = 10
 |pages = 783–793
 |pmid = 24125642
 |s2cid = 1429376
 |doi-access = free
 }}</ref>

===Other types===

A number of bivalve molluscs (other than true oysters and pearl oysters) also have common names that include the word "oyster", usually because they either taste like or look somewhat like true oysters, or because they yield noticeable pearls. Examples include:
* [[Thorny oyster]]s in the genus ''Spondylus''
* Pilgrim oyster, another term for a [[scallop]], in reference to the scallop shell of St. James
* [[Saddle oyster]]s, members of the [[Anomiidae]] family also known as jingle shells
* [[Dimyidae|Dimydarian oysters]], members of the family Dimyidae
* [[Windowpane oyster]]s

<gallery widths="175px" heights="175px">
File:Crassostrea_gigas_p1040847.jpg|[[Pacific oyster]]
File:Ostrea edulis Marennes p1050142.jpg|[[Pacific oyster]], opened
</gallery>

In the [[Philippines]], a local thorny oyster species known as [[Tikod amo]] is a favorite seafood source in the southern part of the country.<ref>{{Cite news|url=http://www.worldngayon.com/2011/12/native-oyster-species-in-surigao-del-sur-draws-attention-for-rd/|title=Native oyster species in Surigao del Sur draws attention for R&D {{!}} eVolved|date=2 December 2011|work=eVolved|access-date=12 December 2017|language=en-US}}</ref> Because of its good flavor, it commands high prices.