13 May 2025
Cuttlefish are solitary creatures so researchers were surprised to discover that the animals routinely use complex arm gestures when they see another cuttlefish.
Sometimes they’d raise a pair of arms, almost as if waving, which the team dubbed the “up” sign. At other times, the animals swept all their arms to one side (“side”), folded them beneath their heads (“roll”), and touched just the tips of them together (“crown”).
— Science Magazine: Watch cuttlefish communicate—with enthusiastic gestures
To confirm that common cuttlefish (Sepia officinalis) keyed on each other’s gestures, researchers played videos of a gesturing animal to one in the tank. The tank cuttlefish responded with more gestures, not merely mimicking (mirroring) the video.
The gestures generate sound/pressure waves that cuttlefish respond to even when they can’t see the animal who is gesturing:
The scientists observed the cuttlefish “signing” this way when they couldn’t see each other, so they used a hydrophone to capture the pressure waves produced from each sign. When the researchers then played back this sound for the animals without any visual cues, the cuttlefish often responded by signing—particularly right by the hydrophone, the researchers noted to Live Science.
— Science Magazine: Watch cuttlefish communicate—with enthusiastic gestures
See gesturing cuttlefish respond to these cues in the video below. (If the narration is difficult to understand, turn down the sound and read the text.)
The next step will be to figure out if this is cuttlefish sign language.
Read more at Science Magazine: Watch cuttlefish communicate—with enthusiastic gestures.
For a deeper dive into the intelligence of cuttlefish see this 10-minute video about delayed gratification. It includes cute kids doing a similar delayed gratification experiment + speculation on why cuttlefish can wait for prey to become available.