To Mimic or Not to Mimic

Above is a brown mimic, a white-v (also called long-arm octopus), and then the last two shots are of a mimic showing different hues.

The best episode of mimicry I have witnessed by an octopus was actually done by a coconut octopus, copying a hermit crab, complete with the shell entrance being off-centre and the shell being larger at one end. It certainly fooled me until I got too close and the octo realized that his “walking on tip-toes hermit crab” impression wasn’t working, so it abandoned the valiant and memorable effort, “breaking character” and instantly reverting to being a coconut octopus sitting on the substrate in a lump. I had been fooled, but was simply swimming in that direction, otherwise I would never have thought otherwise. I recounted the experience to Crissy Huffard, a friend who is an octopus researcher from Berkeley and she one-upped me, reporting seeing an octopus in Fiji doing the same, but adding stripes on the legs to enhance the disguise. So perhaps the mimic just has a better press agent than his bretheren.

Personally, I feel that a wonderpus puts on a better show than a mimic as they are usually less shy. But the mimic does copy specific creatures more clearly. I have seen a mimic, all alone and not under any attention or threat, sit atop a sand mound with the outer half of each arm pointed to the surface, possibly copying a sand anemone. A sea snake impression is more obvious and understandable. Bobbing a head from a hole like a mantis shrimp along with looking like a small cuttlefish, or “being” a jellyfish up in the water column are other obvious impressions. It is natural for many creatures under threat to puff themselves up and splay their arms in order to appear larger than they are.