Cuttlefish Are Adorable When They Try to Imitate Hermit Crabs

The pharaoh cuttlefish... cute, unless you happen to be its prey. Wiki Commons

Pharaoh cuttlefish are cute, eccentric little cephalopods that might be some of nature's greatest actors. Thanks to their malleable soft bodies and phenomenal color-changing abilities (they possess 200 specialized pigmented cells, called chromatophores, per square millimeter), they are capable of mimicking everything from the shapes and colors of rocks to other creatures.

When they mimic hermit crabs, it's pure adorableness.

A series of videos recently released as part of a study by scientists at the University of Ryukyus in Japan showcases cuttlefish exhibiting this curious behavior, reports National Geographic. You can view some of the footage yourself right here:

As shown in the video, the cuttlefish display arm movements that look just like the finicky leg gestures made by hermit crabs. It's a convincing impression, and pretty darn cute to witness. That is, unless you happen to be cuttlefish prey...

Lead researcher Kohei Okamoto and colleagues hypothesize that the cuttlefish may be emulating hermit crabs in a devious plot to inconspicuously approach their prey. The study found that the cuttlefish that were pretending to be crabs snagged twice as many fish as those that were employing some other tactic.

It's a clever strategy. Hermit crabs are filter feeders, so they don't pose a threat to animals that the cuttlefish like to hunt. Fish and other prey therefore don't give a second thought to the approaching crab-shaped cuttlefish. The strategy might also help to protect the cuttlefish from predators of their own, since hard-shelled hermit crabs don't usually top the list of desirable quarry for many creatures.

The complex behavior also comes with some mystery attached. The cuttlefish in the study were hatched in the lab, so they have never actually encountered any hermit crabs. How, then, did they learn how to act like crabs?

“Are they learning from actual direct observation or is this programmed into genetics? [This] kind of brings up an interesting question about intelligence and complex behaviors,” said researcher Ryuta Nakajima.

The circumstance would seem to suggest that this behavior is programmed in, but researchers are also considering the possibility that cuttlefish can learn from observations they make while still in an embryonic stage of development. Either way, it's amusing conduct.

The study was published in the Journal of Ethology Ethology.