A “mimic octopus” in the Atlantic : flatfish mimicry and camouflage by Macrotritopus defilippi

Author Posting. © Marine Biological Laboratory, 2010. This article is posted here by permission of Marine Biological Laboratory for personal use, not for redistribution. The definitive version was published in Biological Bulletin 218 (2010): 15-24.

RTH thanksthe Sholley Foundation and ONR grant N000140610202 forpartial support. ACW thanks the Our World-UnderwaterScholarship Society, and AB is grateful for funding fromPOCI 2010 and Fundo Social Europeu through the Fundac¸a˜o para a Cieˆncia e a Tecnologia, Portugal.

The sand-dwelling octopus Macrotritopus defilippi was filmed or photographed in five Caribbean locations mimicking the swimming behavior (posture, style, speed, duration) and coloration of the common, sand-dwelling flounder Bothus lunatus. Each species was exceptionally well camouflaged when stationary, and details of camouflaging techniques are described for M. defilippi. Octopuses implemented flounder mimicry only during swimming, when their movement would give away camouflage in this open sandy habitat. Thus, both camouflage and fish mimicry were used by the octopuses as a primary defense against visual predators. This is the first documentation of flounder mimicry by an Atlantic octopus, and only the fourth convincing case of mimicry for cephalopods, a taxon renowned for its polyphenism that is implemented mainly by neurally controlled skin patterning, but also—as shown here—by their soft flexible bodies.