Northeastern University student Aidan Sasser has learned that when 15 research subjects look identical, it’s their personalities that distinguish them — even when they’re octopuses.
Sasser, a fourth-year student, recently completed a co-op at the Marine Biological Laboratory in Woods Hole, Massachusetts, where he conducted research on how octopuses manipulate objects with the suckers on their arms.
Sasser did this by training California two-spot octopuses — which can curl up into a coffee mug or spread out to the size of a dinner plate — to reach into a series of boxes to interact with agarose discs embedded with prey extract.
The procedure is filmed so that researchers can then analyze patterns of how the octopuses recruit other suckers to help manipulate the “prey” with their suckers. These sucker recruitment sequences enable researchers to determine the path of the neurological signals traveling from sucker to sucker on the octopuses’ arms.
“Nobody knew how these suckers are communicating with one another and what neural pathways were involved — how independent of the central brain are these arm suckers?” Sasser says.
And although he could not divulge much until the research is published, Sasser says “we have a good idea of how this works now.”
This could have benefits far beyond the world of cephalopods..
“Sucker attachment patterns could provide inspiration as a model for soft robotics to create better ways for robots to explore and interact with the environment around them,” Sasser says. “The versatility offered by the octopus arm is unique in nature, and engineers have been interested in applying it to robotics.”
But the co-op is not all research.
Sasser is also the caretaker of the octopuses, around 50 adult cuttlefish also used in other experiments and 40 juvenile cuttlefish to be used in future experiments.
“It’s a lot of animals,” Sasser says. “Definitely, over half my day is spent taking care of animals.”
But his interest in marine biology, as well as a previous co-op in animal husbandry at the New England Aquarium, prepared Sasser well for these tasks.
And while he may not be able to tell them apart by sight, Sasser’s constant interactions with the animals let him distinguish them by other means.
Nori, for instance, was particularly difficult to work with, but was often interacting with objects floating in the tank,” Sasser says.
Mustang, meanwhile, is a large octopus that was strangely interactive with a floating toy strawberry.
Then there is Joe “the abnormally friendly cuttlefish.”
Such strong behavioral differences can have consequences, however.
“A lot of these behavioral experiments take a long time, particularly with octopuses because they often outsmart the experimenter,” says Kendra Buresch, a lab manager at the biological lab.
Sasser agrees.
“They are extremely clever and adaptive, and they often accomplish new tasks in novel ways that are outside of the experimental protocol,” Sasser says. “But they are fascinating creatures to work with.”