Shell · Genus
Spirula
Ram's horn squid
Spirula spirula is a small deep-sea squid whose internal, loosely coiled, chambered shell about 2 cm across washes up on tropical and subtropical beaches by the thousand. It is the closest living analogue to the internal shells of some fossil cephalopods. Beachcombers collect them free; they are useful teaching specimens for chambered shells.
| Habitat | Deep-water squid; shells float and strand on beaches |
|---|---|
| Regions | Worldwide warm oceans |
| Family | Spirulidae |
| Authority (WoRMS) | (Linnaeus, 1758)· WoRMS / MolluscaBase |
| Status (WoRMS) | accepted· WoRMS / MolluscaBase |
| Extinct (WoRMS) | no· WoRMS / MolluscaBase |
| Classification (WoRMS) | Animalia › Mollusca › Cephalopoda › Spirulida › Spirulidae· WoRMS / MolluscaBase |
CITES and protection
Not CITES-listed.
Care (Byne's disease)
Tiny chambered shells are fragile.
Elsewhere
- WoRMS AphiaID: 141548
- Wikidata: Q17302116
- WoRMS / MolluscaBase record
- CITES Appendices
- Wikipedia: Spirula
Cite this article
Stratum Strata. "Spirula" (Shell family). Stratum Strata pack 2026.09, as of 2026-09-21. https://stratum.black/strata/shells/spirula. Accessed 2026-09-21.
@misc{stratum-spirula,
title = {Spirula},
author = {{Stratum Strata}},
howpublished = {\url{https://stratum.black/strata/shells/spirula}},
year = {2026},
note = {Shell family article, Stratum Strata pack 2026.09, as of 2026-09-21; sources: stratum, worms, commons, wikidata. Accessed 2026-09-21.}
} 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.