Pharaoh Cuttlefish Pretending to be a Hermit Crab

by spotmydive

Kohei Okamoto and his team, Japanese scientists from Ryukyus University in Okinawa, discovered a behavior for the least surprising in the Pharaoh cuttlefish.
By feeding them, the observed they disguised in hermit crab, little crustacean with crab legs, who, to protect his soft stomach, squat the shells of gastropods. The researchers saw them assembled their tentacles, and as they possessed articulations, stand some of them and fold other, and then move them independently. They also observe that some parts of their skin have become darker. The scientists filmed them and the videos are astonishing, the behavior and the transformation of the cuttlefish are such that we have the impression to have hermit crab right under your eyes!
This behavior also happen when the mollusks have been transferred in biggest ponds.

Cuttlefish and behavior imitation

For what reasons the cephalopods disguised themselves? The scientists make two assumptions :

  • The hermit crab is not a hunter, he feed himself with only remains of animals or plants, so he is inoffensive for the cuttlefish’s preys. By imitating him, the mollusk can approach the prey without any problem. Besides the team observed that the Pharaoh cuttlefish, which imitate the crustacean, catch twice as more fishes.
  • Crab and hermit crab possess a shell to protect them which is not the case of the cuttlefish. By taking their aspect, it’s very likely that he protect himself from his predators by having them believe his body his protected.

All cuttlefish of the study were born in a laboratory and so they never seen a hermit crab. How can they imitate them? “[that] raises a very interesting question about the animal intelligence and the complex behaviors”, declared Nakajima. According to him, a theory is the cuttlefish have observe crustacean and have learn from this behavior during her embryonic phase.

To confirm that it is a volunteer imitation, the researchers will have to continue their observations. We will have to wait to know a little more.