An octopus can taste what it touches

When an octopus runs an arm across rock, hundreds of suckers gather more than texture. Researchers have identified specialised receptors in sucker cells that respond to poorly soluble molecules on surfaces. Those signals help the animal examine a crevice without placing its mouth—or even its eyes—near whatever is hiding there. Touch and chemical sensing arrive together.

Calling this “tasting with its arms” is useful shorthand, not a claim that a sucker experiences flavour as a human tongue does. The experiments characterised receptor families and cell responses in octopus species; they did not translate subjective experience. What they show is stranger and firmer: an arm’s contact with the seafloor can carry chemical information into a highly distributed nervous system.