noun
eggcase of the greater argonaut
Refers specifically to the delicate, papery shell-like eggcase produced by the female greater argonaut.
See also: 貝蛸
海岸でアオイガイの卵殻を見つけた。
I found an eggcase of a greater argonaut on the beach.
noun
greater argonaut; paper nautilus
Colloquial use for the animal itself (Argonauta argo), though technically the term refers to the eggcase.
アオイガイは暖かい海に生息している。
The greater argonaut lives in warm seas.
貝蛸 is another name for the greater argonaut, but アオイガイ is more common in everyday contexts.
The name アオイガイ literally means 'hollyhock shell', from the resemblance of the eggcase to an 葵 (hollyhock) leaf.