Octopuses can determine which food sources are good to eat and which have gone bad just by touching them. A new study found that this is due to the surface microbiomes and the octopuses’ highly sensitive suckers. The study was conducted by a team from the lab of Nick Bellono, a Harvard biologist who specializes in molecular adaptation.
It was found that octopuses have chemical sensors located in the suckers on their eight arms. These sensors let them “taste by touching.”
The team’s new findings provide further insight into how octopuses perceive their environment. They are especially adept at distinguishing between healthy and unhealthy compounds.
Margaret McFall-Ngai, a physiologist and biochemist at Caltech who was not part of the research, said the study was “the most breathtaking paper I’ve read in a long time.
Bellono and postdoctoral researcher Rebecka Sepela observed that mother octopuses would often select certain eggs from their clutches and discard them. When they looked at the discarded eggs under a scanning electron microscope, they found that the eggs were covered in microbes. This led the researchers to grow nearly 300 strains of microbes.
They wanted to see how the chemicals the microbes make could activate the octopuses’ chemical sensors. “The idea was, if a microbial strain could activate a receptor, then it could generate a neural signal that tells the octopus: This is something I care about,” Sepela explained. Sepela and her team did find specific compounds that triggered the sucker-based receptors.
For example, they discovered that the bacterial species Vibrio alginolyticus makes a chemical called H3C on the decaying shells of dead crabs.
Octopus’ chemical sensing abilities
When the researchers put that chemical on plastic toy crabs, the octopuses avoided those crabs.
They preferred the non-tainted versions. The team also found that another microbe, Vibrio mediterranei, showed up on octopus eggshells. It produced a compound called LUM when the eggs were not viable.
When the team created fake gel-based eggs coated with the substance, the octopuses discarded them. They chose to take care of the microbe-free eggs instead. “The microbiome is acting almost like a chemical translator,” said Sepela.
It integrates environmental signals – like changes in temperature or nutrient levels – and outputs molecules that inform the octopus how to behave.
This study uncovered more information about octopuses. However, the researchers believe their findings could also help us understand how microbiomes affect the behavior of other species. We already know how human internal microbiomes can shape behavior.
The team is interested in exploring how external microbial communities may influence animal behavior in the wild. The octopus gives us a way to study cross-kingdom communication with reduced complexity,” Bellono said. “It’s a system where we can link a microbial signal directly to a behavior – whether that’s predation or parental care.”
The study has been published in the journal Science.
Kirstie a technology news reporter at DevX. She reports on emerging technologies and startups waiting to skyrocket.
