Scents and Sensibility: Cuttlefish Can Distinguish Between Senses

Cuttlefish can remember whether they previously encountered an item through smell or sight up to 3 hours later.

Sepia officinalis. Credit: Gerrit Huurman

Cuttlefish are known to have advanced cognitive abilities; they communicate with each other visually by changing the colour and texture of their skin, as well as through posture and movement, and they even signal to other species. They were also the first invertebrates known to have episodic memory: they adapt their foraging behaviour according to what they ate where and when, that is, they can remember the context of an event as well as the event itself.

Researchers from the EthoS (Animal & Human Ethology) research group in France were keen to work out if the cuttlefish could use this episodic memory to recall what sense they had experienced a stimulus with. The team trained European cuttlefish to associate 3 different panels with different experimental conditions - smell, see and control. During the tests, a glass tube and a beaker of seawater were then placed in the tank, with a visual stimulus in the tube, an olfactory stimulus in the beaker or neither (the control).

After training on familiar stimuli of shrimp and crabs (a cuttlefish's favourite treats), they were introduced to other delicious stimuli like mussels, snails and seaweed. These were placed in the tank either as a visual stimulus or olfactory stimulus and the panels placed in the tank for the cuttlefish to choose between. The cuttlefish chose the correct panels whether they were placed in the tank straight away or after a 1- or 3-hour delay, showing, as the scientists had hoped to prove, that not only could they tell what the stimulus had been at the time, but they could retrieve this information later.

According to the authors, this is the first example of an animal showing the ability to discriminate between senses, and they hope the experimental design in particular will help identify other species that might also display this ability.

https://doi.org/10.1038/s41598-020-62335-x

Billard, P., Clayton, N.S. & Jozet-Alves, C. Cuttlefish retrieve whether they smelt or saw a previously encountered item.Sci Rep 10, 5413 (2020)