A Squid-tastic Night Out
How do you fossilize a squishy squid? Do octopuses see in color, and do they have arms or tentacles? Which came first, the hard-shelled nautilus or the soft-bodied octopus, squid, or cuttlefish? And what does ‘cephalopod’ mean, anyhow?
This week, Ira ventured to the Maritime Aquarium in Norwalk, Connecticut for a special Cephalopod Week celebration. He was joined by experts Barrett Christie, the director of animal husbandry for the Maritime Aquarium, and Christopher Whalen, a postdoctoral researcher and invertebrate paleontologist at the American Museum of Natural History in New York.
They also discussed the challenges of caring for cephalopods in an aquarium environment, some of the amazing abilities of these animals, and what it’s like to discover a previously unknown cephalopod genus and species in fossilized material stored in museum archives. Together, they tackled audience cephalopod questions large, small, and multi-armed.
You can listen to a full version of the Q&A with the experts at the event below.
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Barrett Christie is Director of Animal Husbandry at The Maritime Aquarium in Norwalk, Connecticut.
Christopher Whalen is a postdoctoral researcher and invertebrate paleontologist at the American Museum of Natural History in New York, New York.
IRA FLATOW: This is Science Friday. I’m Ira Flatow. We’re coming to you from a Cephalopod Week celebration at the Maritime Aquarium in Norwalk, Connecticut. Hey! Thank you, all!
Let me Welcome my guests. Our first guest, he’s the director of animal husbandry here at the Maritime Aquarium. He’s going to tell us what it’s like to work with octopuses. He’s written the go-to manual on cephalopod care. Please welcome, Barrett Christie.
My next guest, he’s a post-doctoral researcher and invertebrate paleontologist at the American Museum of Natural History, down the road of piece in New York City. And earlier this year, he described a whole new cephalopod found in fossil records. Please welcome, Christopher Whalen.
Thank you both for being with us today. First question to Barrett– tell us a bit about what you do at the aquarium. What does it mean to be the director of animal husbandry?
BARRETT CHRISTIE: Yeah, sure thing. So here at the Maritime Aquarium, we have a very diverse collection of animals. We have 20-some-odd biologists that have different specialties. And we manage them in order to care for the huge variety of animals here at the aquarium– almost 6,000 individual animals, representing 370-some-odd different species, ranging from corals and sponges, all the way up to the cephalopods, of course fishes. You guys may have seen the harbor seals out there. It takes a lot of care to keep this collection going.
IRA FLATOW: What surprises you most about your job?
BARRETT CHRISTIE: The thing that never fails to surprise me about this job, I would say more than anything, just how destructive animals can be and how much they can always lay your best plans to waste. You can never predict what a common day is going to be like here in the aquarium. And that’s kind of the beauty of working in this field is you learn something different every single day. And there’s always a new challenge and a new opportunity.
IRA FLATOW: We’ve talked about cephalopods for years on end, here. And we’re always fascinated by the octopuses, about how clever and smart they are. Tell us about how you’ve learned about that?
BARRETT CHRISTIE: That’s a great example. Everybody knows cephalopods are smart, especially the octopods. They tend to be, in my opinion, anecdotally at least, the most intelligent of all the cephalopods. They can unlock these amazing prey puzzles. We saw some of the arms reaching in and grabbing a food item.
Everybody knows the classic experiment. An octopus can easily open a jar. I’ve even worked with some that can learn to discriminate sound. Now, they hear at a very low frequency, less than 20 hertz, which is 20 vibrations per second. But they can even discriminate the tune of a song slowed down to less than 20 hertz, to know when it’s time to feed.
They can recognize their individual caretakers. So if I work with an animal every single day, that octopus will recognize me, even through the water as it looks up when I come for feeding time. And if I’m off– if it’s a holiday, and somebody is filling in– they’ll actually recognize that, hey, that’s not my caretaker. That’s not my feeder. So certainly, absolutely the most intelligent of all of the invertebrates, hands down.
IRA FLATOW: Wow. Now, Chris, tell us about this new species of extinct–
CHRISTOPHER WHALEN: Genus and species, yes.
IRA FLATOW: And it had 10 arms, is that correct?
CHRISTOPHER WHALEN: Yeah.
IRA FLATOW: Because that’s not something we have today.
CHRISTOPHER WHALEN: Well we have 10 arms with squids and cuttlefish today, right. But the unique thing about this fossil is, it’s the oldest relative of octopuses, which of course, by name, all have eight arms.
So the vampire squid is sort of a living fossil to understand early octopuses. And they also have eight arms. But in addition to that, they have these two thin filaments. Those filaments have always been thought to be the vestigial remnants of an additional two-arm pair– the same arms that we see in squids. But we’ve never had a fossil that could actually demonstrate that before. So this is a pretty exciting find, to be able to prove something that we’ve thought we’ve understood for a long time.
IRA FLATOW: Wow. And did you give it a name?
CHRISTOPHER WHALEN: Yeah, we named it Syllipsimopodi bideni.
IRA FLATOW: And how do you take that name apart? Why did you name it?
CHRISTOPHER WHALEN: So the genus, Syllipsimopodi, it means prehensile foot, which is because the arms of a cephalopod are modifications of the molluscan foot. So this is that organ you see at the bottom of a snail. It’s the same structure there that you’re seeing in cephalopod arms. And prehensile because in addition to having 10 arms, like you mentioned, this is also the oldest fossil we have to preserve suckers on those arms, which is pretty rare for a fossil. There’s only a handful of those known. But this is the oldest.
IRA FLATOW: I’m wondering how you get a fossil if it’s such squishy material to begin with. How does it get fossilized?
CHRISTOPHER WHALEN: Yeah. So we have a lot of fossil cephalopods, but most of them, you’re right, are the hard materials– the shells or the gladius, which is this chitinous remnant of a shell. The soft tissues themselves, you only get in these exceptional localities, typically characterized by having no oxygen in the area for some short interval of time.
So an animal swims into this deoxygenated zone. Or the zone moves into the area where the animal is. They die. They suffocate. But also, they can’t be scavenged by any predators. And it’s difficult for them to decompose because of the lack of oxygen. So then they can settle down. And if you have a very gentle environment– low current, fine-grained mud, not rocky– then the animal can lay there, get buried, and you’ve got a fossil.
IRA FLATOW: Now, Barrett, I know, as I said before, you helped write the animal care manual for giant Pacific octopus. Is octopuses and octopi same thing? Can you say either way? Or is it octopuses?
BARRETT CHRISTIE: According to Merriam-Webster, you can use octopi. The traditional plural is octopuses. Technically, it’s octopodes, because it derives from–
IRA FLATOW: It’s what?
BARRETT CHRISTIE: Octopodes, because it derives from the Latin not the Greek. Nobody says octopodes. Only real nerds say that.
IRA FLATOW: After tonight everybody’s going to be going home saying–
BARRETT CHRISTIE: Octopuses if you’re referring to more than one animal of an octopus, could be multiple species. Or octopods, I like to use, if you’re referring to multiple different species within the order Octopoda.
IRA FLATOW: Octopoda.
BARRETT CHRISTIE: Octopoda.
IRA FLATOW: OK. Now you write a manual, if I open up the chapters of your manual on Octopoda care, what am I going to see in there? What are some of the clues and the hints you’ll tell me about taking care of the octopuses?
BARRETT CHRISTIE: So these things are amazing predators that have evolved metabolisms higher than anything else we keep in aquariums. The metabolism in an octopus is actually multiple times higher than the most energetic fishes. Think mako sharks, and albacore tunas, and all these– marlin, high-performance swimming machines. An octopus– the lowly, common octopus– has an order of magnitude higher metabolism than many of those species.
So they’ve got to eat a lot. We know that from the science. They have to eat a lot. They have to eat pure protein because they actually don’t have the emulsifiers in their gut to absorb things like lipids and fats and oils. They can’t take those in. So they need a very lean protein source. And they need a whole lot of it. But also, their water temperature– they have extremely sensitive water temperature requirements.
Cephalopods in general are some of the– if not the– most sensitive animals we keep in aquariums, because their skin is what we call a microvillous epidermis. It’s a single cell layer thick. So any contaminant in that water immediately gets transferred into their bloodstream. We have a pretty good integument. Our skin is pretty thick and good at keeping things out. Fishes have skin and scales. Octopus don’t have that.
So there’s quite a bit in there about their behavior, but also their water quality needs, their temperature requirements, and the nutritional requirements, and even cephalopod medicine. Yes, it is possible. There are veterinarians, now, that specialize in cephalopod medicine. And we know which drugs we can and cannot use on these animals.
IRA FLATOW: Can you take one home and make a pet?
BARRETT CHRISTIE: I will say absolutely, with the caveat you can absolutely keep an octopus at home if you are a highly skilled aquarium keeper and you know what you’re getting into. These animals need a big amount of space compared to the size of the animal. They need very exact water quality requirements. So you need to be an accomplished saltwater reef keeper to start with. And they’re very expensive. We heard about how fast they grow. Some young octopods can grow 5% of their body weight per day. And they can eat twice that.
IRA FLATOW: That’s a big food bill.
BARRETT CHRISTIE: It’s a huge food bill.
IRA FLATOW: What’s their favorite food?
BARRETT CHRISTIE: So most octopods are going to feed predominantly on bivalves and crustaceans in the wild. So are they’re eating clams, and they’re eating crabs. About 60% for most species– 60% clam or bivalve diet, and about 40% of that is crustacean or crabs.
IRA FLATOW: Now, Chris, you spend a lot of time in what people refer to as “the stacks” in a museum, right?
CHRISTOPHER WHALEN: Yes.
IRA FLATOW: What do you do there? How exciting could that be, going through the stacks? For you, it must be very exciting.
CHRISTOPHER WHALEN: It can be exciting, yeah. It all depends what you’re looking for. The most exciting drawers, as they say, are the ones that they’re labeled “unknown” or “cephalopoda indet,” for indeterminate. So you just, when you visit a museum, if you’re a paleontologist, most of the collections are behind the scenes. On display is maybe 1% or less of what the museum’s holding. And they keep them there so people can do these types of evolutionary studies.
If you want to understand how organisms are related to one another, you can use DNA. But the other big piece of evidence you use is fossils. The problem with working on fossils is it takes a lot of time and a lot of study to become an expert in any one group.
So this fossil that we talked about earlier, for example, that was sitting at the Royal Ontario Museum for about 30 years or so before somebody– it happened to be me, but could have been any cephalopod expert– saw it and realized it was a different genus and species from something that had been described.
IRA FLATOW: Let me bring you back to that moment of discovery. Here you are in the stacks. You’re looking through fossils. And you say, oh, this looks different. Would that be an accurate way to describe it?
CHRISTOPHER WHALEN: That’s about right, but it’s always a little less glamorous than what you want to say. It’s much more like you’re looking through a dozen or so drawers, and because I was a visiting researcher there, deciding what you want to borrow. So it’s much more mechanical. Like, oh, I don’t know what that is. Let’s set that aside. And I actually, even myself, sat on it for a couple of years before doing anything with this fossil.
The real reason it ended up being a paper and a new species was because one day I happened to notice that it had those suction cups on the arms. And like I mentioned, that is very rare. So that provoked further study and further description. But, yeah, you need something to pique your interest.
IRA FLATOW: Lots of people have questions. Let’s go to our first one.
AUDIENCE: What’s the difference between a octopus and a squid?
IRA FLATOW: What’s the difference?
CHRISTOPHER WHALEN: I can take that the easy difference is the number of arms. Squids always have 10 arms, octopuses, eight arms. So if you can just count them, you can tell them apart.
IRA FLATOW: Next question, please.
AVA: Hi, I’m Ava, and I was wondering, what does the word cephalopod mean?
CHRISTOPHER WHALEN: So it means head foot. I can’t say exactly why it was given that name, but that’s what it means. And I think it’s pretty appropriate, since they’re the most intelligent mollusks by far– if you think of a clam– but also the most intelligent invertebrates.
IRA FLATOW: You’re listening to Science Friday from WNYC Studios. I’m speaking with Barrett Christie and Chris Whalen about cephalopods. Next question, over there.
AUDIENCE: Do octopuses see color differently?
IRA FLATOW: Oh. Good question.
BARRETT CHRISTIE: That’s another excellent question. So octopuses have the same range of color that we see. So they can see all of the colors represented here in the room. But they can’t tell the colors apart. So functionally, yes, they are color blind. But they’re not like a lot of species that are color blind, where they don’t see red or they don’t see blue at the other end of the spectrum. They can actually see all these colors, it just looks black and white.
However, the super interesting thing is they also see polarized light, like you would see through polarized sunglasses. And we’re seeing some recent literature– I say recent. Past 10 years, we’re seeing some literature that the cuttlefishes and the squids can actually communicate with each other using polarized light. So they can make patterns on their bodies and send a signal to each other– like, hey, back off, or, hey, I want to mate with you– that we can’t even see with the naked eye. Only they can see it, because it’s only represented in polarized light.
IRA FLATOW: OK. Next question.
VALERIE: Hi, I’m Valerie. I’m a science teacher from Woodbridge, Connecticut. And I’m curious about the relationship between the nautilus and the nonshelled cephalopods. Is the nautilus the ancestor of the squid, the octopus, and the cuttlefish? And which one came first? Like when the shell, if the shell was discarded and we had evolution–
IRA FLATOW: Yeah, why does not have a shell? When– yeah.
CHRISTOPHER WHALEN: Yeah, so all mollusks, ancestrally, have a shell. And that includes cephalopods. And most of the fossil record we have of these are their fossil shells. This is an active debate. Nautilus split from other cephalopods at a minimum 400 million years ago, alternatively, more like 500 million years ago. And this is an active debate. But those early relatives of squids and octopuses would have also had an external shell.
And then around 380 million years ago, that external shell becomes internalized, more or less like your bones. And most cephalopods today still have either that internal shell or a remnant of that internal shell. So nautilus is a good way to understand what the ancestors of the other cephalopods looked like. But it is not itself an ancestor of those cephalopods, if that makes sense.
And it has some unique characteristics that are just a nautiloid innovation, like the number of arms. If you look at a nautilus, they have something like 90 appendages. And that’s not the ancestral condition. That is a unique innervation of that group of animals.
IRA FLATOW: 90 appendages.
CHRISTOPHER WHALEN: Something like that, yeah. I don’t know the exact count. I don’t know if–
IRA FLATOW: That’s close enough for government work. OK, next question.
PAUL: Hi, my name’s Paul. Would you say that cephalopods are the smartest animals in the ocean or certainly one of them?
CHRISTOPHER WHALEN: Probably not the smartest animals in the ocean, but one of them, because you’ve got to remember you’ve got dolphins in the ocean, too, which are, I think, usually considered the smartest animals besides primates.
BARRETT CHRISTIE: Yeah, I would say that they are by far the most intelligent invertebrate. But remember, whenever you hear people talk about cephalopods, you always hear that qualifier– invertebrate. There are far more fishes, dolphins, marine mammals, that are just an order of magnitude more intelligent.
Your dog at home or even pigs– pigs are highly intelligent animals– dogs and pigs are way more intelligent than cephalopods. Which doesn’t diminish how amazing they are. They’re by far the most intelligent invertebrate. But they don’t really rank up there with the dolphins.
IRA FLATOW: Wow.
CHRISTOPHER WHALEN: They’re cooler than dolphins.
IRA FLATOW: They’re cooler.
CHRISTOPHER WHALEN: They’re just not more intelligent than dolphins.
IRA FLATOW: They’re cooler. All right. I think we have set the record for the number of questions from the audience in a Science Friday segment. Thank you, all.
I want to thank our guests, Barrett Christie, Director of Animal Husbandry at the Maritime Aquarium here in Norwalk, Christopher Whalen, Postdoctoral Research and Invertebrate Paleontologist at the American Museum of Natural History in New York City. Thank you, both, so much for being here this evening. And also, thanks to our partners for tonight’s events, Connecticut Public and the Maritime Aquarium. Thank you, all, here, for taking time to be with us.
And as we say on Science Friday, that’s about all the time we have for today. If you missed any part of this program or you would like to hear it again, subscribe to our podcast or ask your smart speaker to play Science Friday. You can say hi to us all week on social media– Facebook, Twitter, Instagram. Happy Cephalopod Week to everybody. Have a great weekend. I’m Ira Flatow.