ScienceDaily (Aug. 25, 2010) — Paul the Octopus -- the eight-legged oracle who made international headlines with his amazingly accurate football forecasting -- isn't the only talented cephalopod in the sea. The Indonesian mimic octopus, which can impersonate flatfish and sea snakes to dupe potential predators, may well give Paul a run for his money when it comes to "see-worthy" skills.
By creatively configuring its limbs, adopting characteristic undulating movements, and displaying conspicuous color patterns, the mimic octopus (Thaumoctopus mimicus) can successfully pass for a number of different creatures that share its habitat, several of which are toxic. Now, scientists from the California Academy of Sciences and Conservation International Indonesia have conducted DNA analysis to determine how this remarkable adaptation evolved. The research is reported in the September 2010 issue of the Biological Journal of the Linnean Society.
Like its relatives, the mimic octopus is very capable of hiding from hungry predators by blending into its background. However, this talented species often chooses to make itself more conspicuous to predators by mimicking flatfish, lionfish or sea snakes that display high-contrast color patterns. This daredevil maneuver is thought to help T. mimicus confuse or scare away predators. Because it is relatively rare for an animal to develop such a high-risk, conspicuous defense strategy, the authors of the recent study hoped to gain insight into the evolutionary forces that fueled this behavior by conducting genetic research on the mimic octopus and its relatives. They focused on the mimic's ability to flatten its arms and head and swim along the sea floor like a flatfish, while simultaneously exhibiting a bold, brown-and-white color pattern.
Using DNA sequences to construct a genealogy for the mimic octopus and more than 35 of its relatives, the researchers ascertained the order in which the T. mimicus lineage evolved several key traits: 1) First, T. mimicus ancestors evolved the use of bold, brown-and-white color displays, employed as a secondary "shock" defense to surprise predators if camouflage fails. 2) Next, they developed the flatfish swimming technique and the long arms that facilitate this motion. 3) Finally, T. mimcus began displaying bold color patterns while impersonating a flatfish -- both during daily forays away from its den and at rest. In evolutionary terms, this last step represents an extremely risky shift in defense strategy.
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http://www.sciencedaily.com/releases/2010/08/100826093208.htm