Octopuses use their arms to sense and respond to microbiomes on the seafloor

From the beginning of life on Earth, microbes, small but influential single-celled organisms, have shaped the environment that animals must adapt to in order to survive. Distinct microbial populations, known as microbiomes, inhabit nearly every surface on Earth. Now scientists have found that octopuses can detect signals from the microbiomes they encounter, revealing one of the ways these cephalopods navigate their environment.

Humans can also detect signs of microbial activity, such as when we smell that meat has gone bad or milk has spoiled. But we can’t sense those microbes by touch. Octopuses, on the other hand, touch and taste the world with their arms, which collectively have more neurons than their central brain.

Those arms are also lined with chemotactile receptors, which enable them to reflexively react to specific chemical signals from microbiomes as they explore their environment, according to research published recently in Cell. The California two-spot octopus (Octopus bimaculoides). Photo by Anik Grearson. Microbes have long been known to influence internal animal development, disease, and digestion.

To explore whether the microbiomes in our environment also shape external animal behavior, a team led by biologist Rebecka Sepela, a postdoctoral fellow at Harvard University in Cambridge, Massachusetts, chose as their subject the octopus — an animal that does a lot of exploring by touch. “There s a huge interest in this right now. From human biology to animal biology, from agriculture to medicine,” said Spencer Nyholm, an invertebrate zoologist and microbiologist at the University of Connecticut, who was not involved...This article was originally published on Mongabay