Spondylus — Spondylus
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Shell · Genus

Spondylus

Thorny oysters

Thorny oysters (Spondylus) are bivalves cemented to the reef and covered in long spines, in red, orange and purple; Spondylus americanus and the Pacific Spondylus princeps are the showpieces, and a specimen with all spines intact and no encrustation is hard to obtain. Diver-collected, cleaned Spondylus are moderately expensive. They are unrelated to true oysters despite the name.

HabitatCemented to rock and coral, shallow tropical water
RegionsIndo-Pacific, Caribbean, Eastern Pacific, Mediterranean
FamilySpondylidae
Authority (WoRMS)Linnaeus, 1758· WoRMS / MolluscaBase
Status (WoRMS)accepted· WoRMS / MolluscaBase
Extinct (WoRMS)no· WoRMS / MolluscaBase
Classification (WoRMS)Animalia › Mollusca › Bivalvia › Pectinida › Spondylidae· WoRMS / MolluscaBase

CITES and protection

Not CITES-listed; Spondylus was ceremonial currency in Andean cultures and Ecuador regulates harvest.

Care (Byne's disease)

The spines trap salt and dirt; clean before storage.

Elsewhere

Cite this article

Stratum Study. "Spondylus" (Shell family). Stratum Study pack 2026.09, as of 2026-09-19. https://stratum.black/study/shells/spondylus. Accessed 2026-09-20.

@misc{stratum-spondylus,
  title        = {Spondylus},
  author       = {{Stratum Study}},
  howpublished = {\url{https://stratum.black/study/shells/spondylus}},
  year         = {2026},
  note         = {Shell family article, Stratum Study pack 2026.09, as of 2026-09-19; sources: stratum, worms, wikidata, commons, smithsonian. Accessed 2026-09-20.}
}

Citations carry the pack version and the article's as-of date so they resolve to the same text later. The facts themselves belong to the sources listed below; cite those for the science.