Rock oyster

Rock oyster
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Order: Ostreida
Superfamily: Ostreoidea
Family: Ostreidae
Genus: Saccostrea
Dollfus & Dautzenberg, 1920
Type species
† Ostrea saccellus
Dujardin, 1837
Synonyms
  • Ostrea (Saccostrea) Dollfus & Dautzenberg, 1920
  • Parastriostrea Harry, 1985
  • Saxostrea Iredale, 1936

Rock oysters are true oysters of the genus Saccostrea, belonging to the subfamily Saccostreinae of the family Ostreidae. Depending on the environmental factors and the substrates it is found in, individuals can vary greatly in size. They feed on phytoplankton and detritus.

Probably the best-known species is the Sydney rock oyster (Saccostrea glomerata).

Distribution

They are widely distributed in tropical and subtropical regions. They are common along the rocky shores of the Indo-Pacific region. Their range includes East Africa, Japan, Taiwan, China, Vietnam, Singapore, Australia and New Zealand.

Taxonomy

Saccostrea is a genus which belongs to the subfamily Saccostreinae which further belongs to the family Ostreidae (rock oysters). Other genera within this family include Ostrea and Lopha of the subfamily Ostreinae and Crassostrea of the subfamily Crassostreinae.

The taxonomic classification and phylogenetic relationships of oyster species is not exactly known and this is particularly true for this genus. This uncertainty is due to the morphological plasticity members of this genus show along with significantly differing shell morphology based on its life stage and habitat condition. Traditional methods of figuring out its taxonomy are difficult. These methods can only recognize one species within the Indo-Pacific region (S. cucullata) with S. kegaki being the only species readily distinguished.

Phylogeny

Current work suggests that this genus contains two major lineages. The first is the S. cucullata complex. Included in this complex is S. kegaki and S. glomerata. The second lineage is the S. mordax complex.

Taxonomic history

Saccostrea has been placed in either the subfamily Ostreinae or Crassostreinae. However a new subfamily was erected by Salvi et al. (2014) named Saccostreinae which also tentatively included Striostrea as a member (it would later be placed within its own subfamily Striostreinae by Raith et al. 2015).

Species

The World Register of Marine Species lists these species:

Synonyms

References

  1. 1 2 3 MolluscaBase eds. (2022). MolluscaBase. Saccostrea Dollfus & Dautzenberg, 1920. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=138300 on 2022-04-27
  2. ↑ "https://invasions.si.edu/nemesis/species_summary/-725". invasions.si.edu. Retrieved 2026-03-04. {{cite web}}: External link in |title= (help)
  3. 1 2 3 Xie, Dansheng; Li, Fengping; Liu, Mingjie; Fan, Likai; Guo, Xingchen; Wang, Aimin; Liu, Chunsheng; Gu, Zhifeng; Yang, Yi (2026). "New mitochondrial genomes of Saccostrea (Mollusca, Ostreidae) specimens from Hainan Island". ZooKeys (1270): 19–31. Bibcode:2026ZooK.1270...19X. doi:10.3897/zookeys.1270.170554. ISSN 1313-2989. PMC 12936720. PMID 41768311.
  4. 1 2 Katherine Lam, Brian Morton, Morphological and mitochondrial-DNA analysis of the Indo-West Pacific rock oysters (Ostreidae: Saccostrea species) , Journal of Molluscan Studies, Volume 72, Issue 3, August 2006, Pages 235–245, https://doi.org/10.1093/mollus/eyl002
  5. ↑ Salvi, Daniele; Macali, Armando; Mariottini, Paolo (2014-09-24). "Molecular Phylogenetics and Systematics of the Bivalve Family Ostreidae Based on rRNA Sequence-Structure Models and Multilocus Species Tree". PLOS ONE. 9 (9) e108696. Bibcode:2014PLoSO...9j8696S. doi:10.1371/journal.pone.0108696. ISSN 1932-6203. PMC 4177229. PMID 25250663.

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