Sucker it and see: how the octopus uses ‘tentacles’ to taste its food

Researchers found that marine invertebrates triggered differing responses on receptors in the molluscs’ suckers

Octopuses are able to taste their food through the suction-cup-like suckers along their eight tentacles, with new research showing that the molluscs can distinguish between potentially toxic prey and a tasty dinner.

Research published in the journal Cell, suggests that chemicals known as terpenoids – produced by many marine invertebrates in a warning signal – trigger differing responses on the octopuses' receptors and sensory cells in their suckers.

Initially a study into the California two-spot octopus by Nicholas Bellono, a molecular and cellular biologist from Harvard University, and his team found that the animal’s suckers reacted differently when it touched prey compared to something else. The study confirmed the idea that the suckers have a “taste-touch" capacity.

"We also showed that separate and distinct chemo- and mechanosensory cells express specific receptors and exhibit discrete electrical activities to encode chemical and touch information, respectively," Dr Bellono said.

"Our results demonstrate that the peripherally distributed octopus nervous system exhibits exceptional signal filtering properties that are mediated by highly specialised sensory receptors."

The researchers cautioned, however, that many other unknown substances may set off different responses in broadly the same way.