Excerpt:

>The argonaut octopus, of the family Argonautidae, belongs to a group of pale pink-spotted octopuses. Unlike the heroes that sailed the Argo, these octopuses are known for traversing the open ocean by way of a delicate, curved, creamy white vessel—an external casing, often referred to as a “shell,” that gave them their common nickname, the “paper nautilus.”

>These creatures baffled naturalists and philosophers for two millennia, even fooling Aristotle, who believed that they used their large pair of webbed dorsal arms as “a sail” to catch the briny breeze and floated across the ocean’s surface like paper boats.

>“It uses [the thin webs], when a breeze is blowing, for a sail, and lets down some of its feelers alongside as rudder-oars,” Aristotle wrote of the paper nautilus.

>These myths carried weight for centuries, even among naturalists in the 19th century.

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>It wasn’t until the early 1830s when self-taught French naturalist, Jeanne Villepreux-Power began researching the Argonauta argo, or the greater argonaut, that we learned the true origins of their “shells.”

>In the 1800s, most scientists believed that the shell was made by another animal—that argonauts lived in them the same way that a hermit crab will go find a snail shell or a mollusk shell to live in, Finn says. Once the octopus grew too large for the shell, it would abandon the shelter and either search, steal, or kill the original inhabitant for a larger shell.

>But, Jeanne Villepreux-Power sided with the opposite side of the debate: The argonauts were the builders of their cases.

Lauren J. Young, June 20, 2018