Dr. Teresa Iglesias is the team leader for cephalopod support in the Animal Resources Section at the Okinawa Institute of Science and Technology Graduate University (OIST). Cephalopods, which include octopus, cuttlefish, and squid, are known for their amazing color change abilities and cheeky antics.
In the most recent episode of the OIST podcast, science communicator Lucy Dickie caught up with Dr. Iglesias to hear about her research on the sleep-like state that has been observed in cephalopods and the crazy, interesting and fun experiences that have occurred during her career working with these critters.
“It was a group of squid, you know how they swim in formation, and they were all facing me,” said Dr. Iglesias, when asked about the first time she saw cephalopods in the wild. “And I had never interacted with cephalopods before, this was years ago. And I knew they talk with their arms, so I started to move my fingers a bit, pointed at them, raising my pinky and my index finger up towards them and they all started to change colors.”
Dr. Teresa Iglesias at OIST’s Marine Science Station. She says about studying animals, “I think it makes it a much more interesting world.” Photos by Keishu Asada, composite by Teresa Iglesias.
“And now, I think I know better, that raising those two outer arms can be an indicator of annoyance or fear or just, kind of, being on edge. So, potentially, I don’t know if I was communicating to them ‘hey, I’m on edge because you’re looking at me’ or if they were kind of going ‘well, maybe we should be on edge too.’ It could be some sort of response that they have to that kind of gesture that maybe induces some sort of fear response.”
Dr Iglesias studies the interesting sleep-like state that cephalopods exhibit. She explained how, when they seem to be in this sleep-like state, they have very dramatic colors changes, combined with texture changes, eye movement, and arm twitches, and, all of that together had reminiscence of humans’ and mammals’ rapid eye movement (REM) sleep. Some of Dr. Iglesias research with cephalopods involves trying to determine whether this sleep-like state can be classed as the two-stage sleep that mammals, birds, and reptiles have.
A 3-month old cuttlefish (Sepia latimanus) in the active sleep-like state. Photo by Teresa Iglesias.
Cephalopods are useful models to study questions like this because their skin is connected to their brain, so, when they change color, it’s actually an indication of brain activity. “And one of the things we know about REM sleep is that the brain activity mostly looks like awake brain activity.”
Dr. Iglesias cited feeling more connected to nature and to the animals around us as one of the reasons that exploring these questions is important. “We’re human animals, we’re not separate,” she explained. “We’re a little bit different but we’re not separate. And by learning about the animals around us we can, self-centeredly, learn more about ourselves but we can also just learn more about them. There are all these assumptions about the creatures around us that I think are not accurate. And I think it’s a much more interesting world to challenge those assumptions and to make these discoveries about what these creatures around us are doing and experiencing.”
“I think it makes it a much more interesting world.”