Undersea Odyssey: Squid vs. Octopus

Eyewire, citizen science, octopus, squid, Undersea Odyssey, marine biology

Since ocean exploration first began, the almost unearthly qualities of marine life have captured our imagination. Strange shapes, bizarre abilities… and some animals that exemplify these are two distinct cousins in the invertebrate phylum Mollusca, class Cephalopoda. Let’s give a salute to the weird, wild, wonderful squids and octopodes! But though they may seem like tentacular twins, they’re actually built rather differently from one another, and their behaviors vary as a result.


  • Ten limbs total, but only two actual tentacles! These long, suckered limbs grab prey, while the other eight limbs are shorter arms without suckers
  • Two fins, located on their heads
  • Eats fish or shrimp, so the open water is a squid’s preferred habitat
  • Sometimes solitary, but many species form schools, probably a safety move because of where they hang out


  • Eight limbs, all of which are used for locomotion and capturing prey alike… but among scientists they aren’t considered tentacles either, because their suckers don’t cover the full length of the arm!
  • Usually no fins!
  • Eats bottom feeders, so an octopus typically makes its home in a little den somewhere on the sea floor, whether in deep or shallow waters
  • Definitely the more introverted critter; octopodes always live alone

If you had to choose, which of these cephalopods would you like to be? This throwdown starts at 11:00 AM EST on 2/19 and goes for 24 hours! Usual VS bonuses apply.

Swag (generously sponsored by @susi): The top scoring player on the winning team wins a tote bag! Another tote bag and 3 sticker sheets will be raffled among the top 50% of players on the winning team, too.

Artwork by Daniela Gamba