Octopus Chromatophores

AAAS: “Octopus’ quick costume changes are costly affairs.” Cephalopods may make their rapid changes in colorful camouflage seem effortless, ‘but according to a new study published today in the Proceedings of the National Academy of Sciences, it takes a lot of energy.’ Many of these creatures can change from mottled brown to magenta + various other hues in the blink of an eye, either for confusing predators or sneaking up on unsuspecting prey. “Curious about the metabolic costs of these illusory abilities, two researchers at Walla Walla University took 17 skin samples from ruby octopuses (Octopus rubescens, seen above) and exposed them to flashing blue light, causing their chromatophores — pigment-containing cells — to expand and contract.” A custommade respirometer was used to measure the amount of oxygen used by these cells, as a proxy metric for the metabolic energy required. If you need a hard number: “They estimated that a ruby octopus weighing 100 grams uses 219 micromoles of oxygen per hour to achieve a full-body makeover, almost the same as its resting metabolic rate of 237 micromoles per hour,” essentially doubling their efforts. “The hefty price of color camouflage may explain why many octopuses spend so much time hiding in dens, and why deep-sea octopuses — who live in extremely dark waters — have less vibrant chromatophore systems.” So, for all those of you who have been saying ‘octopi’ as the plural all this time, fess up now + get on board with ‘octopuses’ because it has Greek, not Latin roots. So there.