“Cephalopods are not aliens from outer space, but they are the closest we’ve got. They’ve been on an independent evolutionary path from ours for over five hundred million years.”
Before there were mammals on land, there were dinosaurs. And before there were fish in the sea, there were cephalopods―the ancestors of modern squid and Earth’s first truly substantial animals. Cephalopods became the first creatures to rise from the seafloor, essentially inventing the act of swimming. With dozens of tentacles and formidable shells, they presided over an undersea empire for millions of years. But when fish evolved jaws, the ocean’s former top predator became its most delicious snack. Cephalopods had to step up their game.
Many species streamlined their shells and added defensive spines, but these enhancements only provided a brief advantage. Some cephalopods then abandoned the shell entirely, which opened the gates to a flood of evolutionary innovations: masterful camouflage, fin-supplemented jet propulsion, perhaps even dolphin-like intelligence.
Squid Empire is an epic adventure spanning hundreds of millions of years, from the marine life of the primordial ocean to the calamari on tonight’s menu. Anyone who enjoys the undersea world―along with all those obsessed with things prehistoric―will be interested in the sometimes enormous, often bizarre creatures that ruled the seas long before the first dinosaurs.
Danna Staaf is a freelance writer and science communicator with special expertise in cephalopods. Her writing has appeared in Science, KQED, Earther, and io9, and her first book, Squid Empire: The Rise and Fall of the Cephalopods, was named one of the best science books of 2017 by NPR. She holds a PhD in biology from Stanford University and has spoken at dozens of venues, including the Denver Museum of Nature and Science, the main Google campus in Mountain View, public libraries, universities and schools at every grade level. She lives in San Jose with her husband and an unruly collection of kids, cats, and plants.
Squid Empire: The Rise and Fall of the Cephalopods was published in November 2017 by University Press of New England. To find out more click here.
Seriously, you have to ask? All right, fine: Cephalopods are not aliens from outer space, but they are the closest we’ve got. They’ve been on an independent evolutionary path from ours for over five hundred million years. They’ve arrived in the modern world with features that seem incredibly weird to us–elastic tentacles, color-changing skin, suction cups and ink sacs–as well as features that are astonishingly convergent. An octopus eye, for example, has an iris, a lens, and a retina just like yours. Unlike yours, it has no blind spot, no color vision, and it can detect the polarization of light.
Without cephalopods, we would have just one kind of nervous system to study. A mouse, a frog, and even a fish are all so closely related to humans that you could say we all have the same kind of brain. Comparing our brain to an octopus’ brain, however, illuminates a great deal more about how nervous systems work, helping us ask new questions and look for new answers. If you’re at all interested in weird stuff, nothing beats cephalopods for raw coolness. If you’re just interested in humans and how we got to be the way we are–still, nothing beats cephalopods for a truly comparative system.
Cephalopods are remarkably intelligent. Should we feel bad about eating them?
My first impulse is to say “yes.” But that’s too glib, and I’m not into making people feel bad. I am a vegetarian, and I don’t eat cephalopods for the same reason I don’t eat cows or chickens or tuna. I don’t think they need to be considered separately from other animals in that regard. For a lucid and compassionate take on this topic, check out Barbara J. King’s “Calling Team Cephalopod: Why Octopuses Could Never Disappoint.” (link: https://www.npr.org/sections/13.7/2018/03/08/591530441/calling-team-cephalopod-why-octopuses-could-never-disappoint)
What advice would you give to a James Bond supervillain wanting to know which deadly cephalopod species they should restock their lair’s plunge pool trap with?
Blue-ringed octopuses. Despite their small size, these are the only cephalopods that have caused documented human deaths. Their venom contains a potent neurotoxin that can kill a grown human. But then I’d also say to this hypothetical supervillain: don’t bother. Don’t bother yourself, and don’t bother the poor blue-ringed octopuses. They only bite people when they feel really threatened–they’d much rather camouflage themselves and hide–and it’s shoddy supervillainy to make a bunch of innocent octopuses feel threatened all the time. Anyway, you know what’s more deadly than even a blue-ringed octopus? Water. Yeah, all the water that’s already in your plunge pool, because people can’t breathe it. Way more people die by drowning every year than by bites from any kind of wild animal. And with all the time you save by not trying to maintain a finicky venomous animal in a salt-water aquarium, you can get on with some really super supervillainy.
Why is it a big deal that nautiluses are being added to the endangered list?
Nautiluses are the only living cephalopods that still have external shells, and people have been collecting these shells and turning them into jewelry or simply displaying them for hundreds of years (at least). But eventually demand outstripped supply and now many populations of nautiluses are nearly gone. At one location in the Philippines, fishers have to set out a hundred traps to catch a single nautilus, in the same place where their grandparents would catch several nautiluses in each trap. The 2017 inclusion of nautiluses in CITES, the treaty that protects high-profile animals like elephants, is the first legal protection these strange, beautiful cephalopods have ever had. Keeping nautiluses around gives us a living window into 500 million years of evolutionary history–and also preserves the most laughably awkward yet astonishingly efficient swimmers on the planet.
If you could vacation in and around a prehistoric sea, when and where would you go?
I’d have to go to the Ordovician, about 470 million years ago, to see giant straight-shelled cephalopods–the planet’s very first monsters, who ruled the seas long before dinosaurs evolved! The arrangement of the continents was so dramatically different back then that it’s hard to describe exactly “where” I would go. This was pre-Pangaea; most land was glommed together in the southern hemisphere so I guess I’d plop myself somewhere in the watery northern hemisphere and hope for the best.
To be clear, “best” means that I would get to see Cameroceras, a horizonal ice-cream cone over twenty feet long, close enough to count its tentacles, look it in the eye, and find out whether or not it had a beak. Does that mean my vacation would be cut short by entering the digestive system of the earliest giant cephalopod? Maybe, but time machines are notoriously unreliable, and death by Cameroceras could be a better end than trying to make it back home.
If you could Jurrasic Park an extinct species of cephalopod which would you bring back to life?
Nice verbing! I’d bring back one of the heteromorph ammonites for sure. The heteromorphs were a bizarre and diverse group of cephalopods with external shells that lived in the Cretaceous. Most ammonites had spiral shells that looked superficially similar to modern nautilus shells, but heteromorphs broke all the rules. There were heteromorphs with corkscrew shells and totally straight shells, with shells bent like paper clips and shells twisted into knots. No one really knows how or why their shells grew in such strange shapes. I’d probably pick Nipponites, because seriously, friend, what are you doing with a shell like that? (link: https://en.wikipedia.org/wiki/Nipponites)
You’re an expert writing for a lay audience. What’s the biggest tip you have for someone attempting to persuade others of the value of their particular field of specialist study?
Let your enthusiasm show.
You write about the individual scientists who inspired you in your early career. Who are you most excited by today? What are they working on?
Last summer I visited Robyn Crook’s lab at San Francisco State University and was completely captivated. (link: http://crooklab.org/) She and her students study pain in cephalopods, which might sound awful, like poking squid with sticks. But in fact, they were able to use noninvasive techniques to find the first evidence that cephalopod anesthesia actually cuts off sensation, instead of simply immobilizing the animals–a pretty important thing to know for ethical research! Crook is the one who turned me on to the idea of cephalopods as the only truly comparative systems for vertebrates. Since the perception of pain evolved separately in cephalopods, they provide an opportunity to study the evolutionary roots of this sensation, the ways in which it’s useful and the ways in which it can be problematic.
I’m also fascinated by the work of Bret Grasse and his team at the Marine Biological Laboratory in Woods Hole. (link: http://www.mbl.edu/cephalopod-program/) Grasse pioneered the aquaculture of pajama squid and flamboyant cuttlefish at the Monterey Bay Aquarium, and now he’s working with a tremendous array of cephalopod species at Woods Hole to make them available for all kinds of research. I admire his team’s focus on the welfare of the animals, and I can’t wait to see what unexpected discoveries will come from scientists being able to work with so many cephalopods that were considered too finicky to handle before. It may seem weird to make such a big deal out of these “niche” animals, but we should remember that modern neuroscience grew almost entirely from breakthrough research on the giant axon of squid. Cephalopods really do offer unique research opportunities, not just in neuroscience but in robotics (all those flexible arms!), medicine (all those arms can regenerate!) and more.
Where is the best place to go diving with cephalopods?
One of my fellow squid scientists once saw six different cephalopod species while snorkeling off Okinawa–so that’s now on my dream dive list! I’ve always wanted to see the giant cuttlefish matting off Southern Australia, too, and then there are the sites off Seattle where you can see giant Pacific octopus (just don’t try to hunt them, link: https://www.nytimes.com/2013/10/20/magazine/the-octopus-that-almost-ate-seattle.html). One of my favorite cephalopods to watch underwater is the Caribbean reef squid, which can be seen in many places throughout the Caribbean, even just snorkeling. They’re relatively easy to find and follow around, so scientists use them for a lot of the most interesting research on cephalopod communication and social behavior.
Whats next for you?
I wrote a couple of essays for an anthology coming out in October called Putting the Science in Fiction: Expert Advice for Writing with Authenticity in Science Fiction, Fantasy, & Other Genres (link: https://pages.e2ma.net/pages/1887808/9576). It’ll have lots more useful information for that Bond supervillain! I’m also finishing up a novel set in a post-sea level rise future where squid racing has replaced horse racing as a high-stakes, high-adrenaline jockey sport. And of course, I’m always writing short science stories here, there, and everywhere.
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