I am looking for a source that reveals the origin of the name "Crasssostrea gigas". This is an oyster also known under the common names giant oyster, Japanese oyster, Pacific oyster and Portuguese oyster (amongst others).

What I've looked into so far

WoRMS and molluscabase both refer to "Thunberg 1793" page 140, but that refers to Ostrea gigas:

OSTREA gigas description in Swedish?

I did find information on the recent change from Crassostrea to Magallana (https://doi.org/10.2983/035.036.0301), but that does not refer to the origin of the Crassostrea gigas.


What is the origin of the name "Crasssostrea gigas"?

  • $\begingroup$ Are you interested in the etymology of Crasssostrea? $\endgroup$
    – kmm
    Commented Jul 28, 2023 at 15:52
  • 2
    $\begingroup$ Well, would be interesting as well, but ultimately I am looking for a reference where the name is used to describe this specific oyster. I.e. how "Ostrea edulis" has a reference to Linnaeus 1758, p. 699 $\endgroup$ Commented Jul 28, 2023 at 15:55
  • 1
    $\begingroup$ Etymology. From Latin crassus (“thick”) + ostrea (“oyster”). Genus: Crassostrea; Sacco, 1897 $\endgroup$ Commented Jul 28, 2023 at 19:13

2 Answers 2


As I see it, it went down like this:

1753: Linné describes the genus Ostrea

1793: Thunberg describes an Oyster as gigas and puts it in that genus -> Ostrea gigas (Thunberg, 1793) That is the original description and should be the original name of the type specimen.

Over a hundred years later...

1897: Frederico Sacco forms a subgenus (sottogenere) Crassostrea in the Genus Ostrea (Linné, 1753). It is not considered a subgenus anymore, today it has the rank of a genus.

So at some point, Ostrea gigas was taken out of Ostrea (this genus still exists) and into the Genus Crassostrea (or maybe into the Subgenus Ostrea (Crassostrea)). It says here that Crassostrea gigas is a homotypic synonym of Ostrea gigas, so that also backs up that it was "just" a matter of nomenclature.

I could not find the original source that describes the basis of changing the genus. The earliest source I found mentioning Crassostrea gigas is from 1952, Adresses delivered at the Convention of the National Shellfisheries Association (page 82) and there is a reference to findings of Schaefer 1937. So if you look for that you might be able to go back and pinpoint the origin of it at some point.

The entire new Magallana Genus from 2016 (Crassostrea gigas Thunberg, 1793 is its type taxon) is also an interesting read, it seemed to have evoked quite a spat amongst malacologists.

Maybe you can find something in the Biodiversity Heritage Library that helps with your question.


@nika identifies the original description of the species as Ostrea gigas Thunberg 1793. They also identify creation of the subgenus Crassostrea Sacco 1897, which I believe, according to the rules of zoological nomenclature, simultaneously created the genus Crassostrea.

Ostrea gigas was placed in the genus Crassostrea by Gunter (1950). Previous authors had recognized O. gigas as part of the subgenus Crassostrea, but it looks like Gunter is the first to recognize Crassostrea gigas (Thunberg 1793) as belonging to a separate genus.

  • $\begingroup$ Awesome, thanks! It was fun looking into Crassostrea's history and it bugged me that I didn´t find the complete answer $\endgroup$
    – nika
    Commented Aug 6, 2023 at 22:45

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .