“Head-turning intelligence is turning out to be far less rare in the animal world than we once presumed (which makes us the dummies for assuming we were the only ones with any wherewithal at all.” (Courage, 119)
I recently read Octopus! by Katherine Harmon Courage. Already one of my favorite animals for their intelligence and camouflage abilities, I loved delving into the lives of these cephalopods. I could have done without the chapters on eating octopus, as they are off my list of edibles due to their intelligence and charisma, but with over 250,000 tons caught annually, I understand why she included information about the importance of the octopus catch and octopus cuisine. (Especially as we exhaust fisheries and begin eating our way down the marine food web, with species depleted quickly in many regions.)
But the book really gets going after that portion. I could nerd out about all of the octopus facts, and the remarkable diversity of octopuses (e.g., blanket octopuses, venomous blue-ringed octopuses, or the Giant Pacific Octopus) but I want to provide a brief overview of their camouflage tricks and encourage you to read the book.
Octopuses are considered to be the smartest invertebrate. Oddly enough for solitary animals, they learn well through observation, while also engaging in complex behaviors that were not taught (like tool use). They are able to change color, texture, and reflectivity in well under a second to blend in with their background. How do they change so fast? According to Courage, “Teams of researchers and millions of dollars have not yet been able to fully understand or even begin to replicate it” (83). We don’t know how they deal with all of the environmental stimuli, as light scatters everywhere underwater and the ocean bottom is a festival of textures and colors. To hide in plain sight, they use chromatophores to change color, iridophores to change reflectivity and hue, leucophores to adjust white coloring, and muscles to create texture. It’s still not clear how they ‘know’ what to shift to. Scientists think that they may be processing the input locally and instantly, without involving their central nervous system. Not bad for a creature that Aristotle deemed stupid.