Friday Cephalopod: Octopus in disguise

Knobby Argonaut, Argonauta nodosa

Knobby Argonaut, Argonauta nodosa

Also, what’s Brian Switek doing, writing about cephalopods? He’s supposed to be writing about dinosaurs!

But first impressions can be deceiving. In truth, as I later learned from Klug, the paper nautilus is not a close relative of today’s pearly nautilus, nor is it an echo of the long-lost ammonoids. The creature that had ensnared my mind is totally different.

The argonaut is an octopus, and its prehistoric look is created by the way the squishy creature reproduces. The “shell,” Klug says, “is actually an egg case secreted by two specialized arms,” and made of the mineral calcite. As she swims, a female argonaut cuddles her eggs in the shell-like cases pressed against her sides. Lacking cases, male argonauts just look like itty-bitty octopuses.


  1. Becca Stareyes says

    Ah, what a pretty cephalopod.

    (I usually end up thinking that every Friday, but today I’m saying it.)

  2. F.O. says

    That the female of the paper nautilus produces her how shell was the discovery of a female scientist, Jeanne Villepreux-Power inventor of the glass acquarium and anointed “mother of aquariophily” by Richard Owen.