noun
winged argonaut; paper nautilus (Argonauta hians)
A species of pelagic octopus known for the paper-thin shell secreted by the female. The Japanese name literally means 'ship octopus'.
See also: 蛸船
フネダコは薄い貝殻のようなものを作るタコの仲間です。
The winged argonaut is a type of octopus that creates a thin, shell-like structure.
水族館でフネダコの標本を見ました。
I saw a specimen of a winged argonaut at the aquarium.
Compound of 船 (fune, 'ship') and 蛸 (tako, 'octopus'), referring to the shell-like structure that resembles a tiny ship. The exact historical derivation is uncertain.