Things I Learned from Cephalopod Week

Do not taunt the octopus
Do not taunt the octopus
Did you know this week is Cephalopod Week? Me neither. That is, until the wonderful world that is Twitter let me know of this glorious occasion. In the spirit of the much-adored Shark Week, Science Friday declared this week to be the one to celebrate all things tentacled. According to Wikipedia, cephalopods are “exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles (muscular hydrostats) modified from the primitive molluscan foot.”

In my opinion, cephalopods are way cooler than sharks, so I will take Cephalopod Week over Shark Week any week. And to my delight, I have learned more than I ever have about our cephalopodic friends. Despite my love for tentacled creatures, I’ll admit with my English degree with Geology as my obligatory science credit that I didn’t know about of cephalopods prior to this week, so without further adieu, here’s some fun facts I learned this week:

Did you know the plural of octopus is NOT octopi?
This blew my mind, but octopuses is the correct pluralization of octopus, according to Smithsonian’s 10 Curious Facts About Octopuses. Despite the Latin classes of my youth, I had not realized that octopus actually has Greek roots, and NOT Latin roots. Thank goodness octopussies is not the correct pluralization either.

Octopus arms can’t get tangled!
You would think with having 8 arms, there’s a chance an octopus could tie itself into a knot. Fortunately for our tentacled friends, this is not the case. Octopuses seem to secrete an extract that its suckers do not identify as something to attach themselves to. According to this article, octopus extract will stop sucker action where fish extract will not.

Not very vampire-ish
Vampire Squid!
There is such a thing as a Vampire Squid
Let’s hope that the vampire squid does not sparkle if one is washed ashore. Lame Twilight jokes aside, the vampire squid does not actually drink blood. It named as such because of the color of its skin and its resemblance to blood. Vampire squids swim at the deepest depths of the ocean, and as such, the dark color of their skin help ward off predators that may be lurking along the ocean floor.

In fact, vampire squids do not have ink sacs like their other cephalopod kin. Instead, they ward off predators with bioluminescent mucus that takes on a blue hue. Check out this video and learn that despite the translation of its binomial name, vampire squids are actually benevolent creatures. Courtesy of Science Friday:

Cephalopods have been around a long time
They have a long and storied past and have survived numerous extinctions. Numerous! Currently, there are over 800 cephalopod species lurking and swimming in the oceans. In fact, those vampire squids that I mentioned above are in fact descended from a line of cephalopods that have origins prior to the octopuses and squids we know today. According to this blog dedicated solely to vampire squids, the origins of vampire squids puzzled scientists for quite some time.

So many hearts!
So many hearts!
3 Hearts Beat as 1
Cephalopods have multiple hearts — squids, octopuses, and cuttlefish all have 3. Yes, 3! These additional hearts are called branchial hearts, which pump blood out of the “main” (or in proper science terms, systemic) heart to the creatures’ gills. This is in part due to the complexity of cephalopods’ circulatory systems.

For further elaboration, here’s an excerpt from this website: “the blood vascular system [of cephalopods] is closed. There is a striking convergence between the aorta of the cephalopod and vertebrate heart, notably in its structure and the employment of elastic proteins. In addition, similar to the vertebrate vascular system, the cephalopod heart operates a dual system whereby blood pumped to the gills is separate from the system that distributes blood to the rest of the body.”

Cephalopods are quite intelligent creatures
Behind their tentacles lies quite an intelligent brain with a great capacity for memory. In fact, cephalopodic intelligence is the highest of invertebrate intelligence. Cephalopods have demonstrated a great capacity for spatial learning, navigation, and predatory behaviors. Octopuses in particular are known for their dexterity, as they have shown behaviors that include throwing rocks and smashing glass in an aquarium environment.

Do you know your squid facts?
Fact: Squids have bioluminescent organs
Fact: Squids are often mistaken for octopuses (C’mon guys!)
Fact: Squids are some of the speediest invertebrates in the entire world
Fact: More than 300 known species of squid are out there in the ocean
Fact: Squids have such a complex reproduction process that many only mate once in their lifetime
Fact: Average lifespan for a squid is about a year
Fact: Squids are “loners.” They don’t travel in schools and rarely found in groups.
Fact: Some squids are able to live as far as or even more than 13,000 feet deep in the ocean
Fact: We actually don’t know that much about squids because of their preferred hangout of the ocean floor and live far too deep for humans to venture!

Look at this amazing picture of the bobtail squid
Seriously. Look at it! Bobtail squid are kin of the fellow cephalopodic cuttlefish and tend to hang out in the shallow waters of the Indian and Pacific Oceans.

Credit: Todd Bretl at
Credit: Todd Bretl at

Want to know more about Cephalopod Week?
Check out Science Friday’s Twitter. Credit goes to them for the awesome featured image as well as the jumping off point for many of the facts I found.