January 5, 2012
Mimic Octopus Finds Mimicking Partner
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The remarkable mimic octopus (Thaumoctopus mimicus), inhabiting the coast of Sulawesi in Indonesia, swims with relatively little fear of predators in the ocean with its remarkable ability to shift its shape, movements and colors to impersonate toxic lionfish, flatfish and even sea snakes.
This fish would not be remarkable if not for a surprise discovery of a previously unknown ability.
During a diving trip in Indonesia in July, researcher Godehard Kopp of the University of Gottingen in Germany filmed a partnership between the pair of animals, reports Choi.
Kopp saw what appeared to be a black-marble jawfish closely tagging behind the octopus as it moved across the sandy seafloor. The jawfish, with brown-and-white markings similar to ones on the octopus it was following made it difficult to spot among its many arms and the octopus did not seem to notice the fellow traveler at all.
“It´s a pretty unique observation of mimicry – most of the time, a mimicking animal doesn´t actually follow the model it is mimicking,” Rocha told LiveScience. “But the mimicry wouldn´t work otherwise for this jawfish.”
It was suggested that the jawfish rides along with the octopus in order to safely venture away from its burrow to look for food. “The jawfish found a way to get around in the open and not get eaten by anything else,” Rocha said. “It´s not a good swimmer, so any grouper or snapper or predatory fish would easily grab it otherwise.”
Rocha proposes that this jawfish evolved its brown-and-white coloration first and then later discovered the advantage of sticking close to the octopus.
“Those jawfish that did gain this advantage survived more often and got more offspring, so this behavior spread throughout the population,” Rocha explained.
“Unfortunately, reefs in the Coral Triangle area of southeast Asia are rapidly declining mostly due to harmful human activities. We may lose species involved in unique interactions like this even before we get to know them.”
Rocha, Kopp and their colleague Rich Ross detailed their findings in the December issue of the journal Coral Reefs.
Image 2: The jawfish mimics Thaumoctopus mimicus, an octopus that mimics fish. Credit: Godehard Kopp
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