Argonauta — Argonauta
Argonauta Original uploader was Bernd Hofmann at de.wikipedia, Wikimedia Commons, CC BY SA 2.0

Shell · Genus

Argonauta

Paper nautilus

The paper nautilus (Argonauta) is an octopus whose female secretes a thin, ribbed, boat-shaped egg case that is often mistaken for a true nautilus shell; Argonauta argo, A. hians and A. nodosa are the collected species. Egg cases are fragile and light, and complete large ones are worth a few hundred dollars. It is not the chambered nautilus and needs no CITES permit.

HabitatPelagic, open warm oceans; the female secretes the egg case
RegionsWorldwide warm oceans, Mediterranean, Australia, Japan
FamilyArgonautidae
Authority (WoRMS)G. Karsten in A. Engler & K. Prantl, 1928· WoRMS / MolluscaBase
Status (WoRMS)accepted· WoRMS / MolluscaBase
Classification (WoRMS)Chromista › Heterokontophyta › Bacillariophyceae· WoRMS / MolluscaBase

CITES and protection

Not CITES-listed (unlike the true Nautilus); some Australian and Japanese beaches see mass strandings.

Care (Byne's disease)

The egg case is paper-thin calcite; store in a rigid box and never in wooden drawers.

Elsewhere

Cite this article

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

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

Sources for this article: Stratum editorial (Stratum editorial);WoRMS / MolluscaBase (CC-BY-4.0);Wikidata (CC0);Wikimedia Commons (CC-BY-4.0). As of 2026-09-19; Study pack 2026.09. Data reproduced under the licences shown; text in Stratum's own words unless a section names its source.

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