A few months ago a friend sent me a button-pin that says "Cthulhuists Do It Tendrilly"---in a kind of Valentine's Day motif (the Cthuluh are fictional characters authored by HP Lovecraft; they have a beard-like mass of cephalopodic tendrils hanging from their faces, and have become adored by cultists---the story says their ET ancestors colonized the deep ocean, and have been awaiting the opportunity to emerge.) Purely by coincidence I'd been watching YouTube vids of cuttlefish, phylogenic relatives of nautiluses; and then, also coincidentally, I watched the old scifi-horror classic "The Fly" (starring Vincent Price).
You can probably see where I'm going here: hybridizing the YouTube vids and "The Fly", I ended up with a creature whose transported molecules get mixed up with a cuttlefish's, yielding a human body with a cuttlefish head. Trippy! It looks just like a Cthuluh!
Anyways, it occurred that the link between cephalopod skin and brains is the functional product of the analogue- computer of evolution that also could function as a repurposed information collection, storage, access and communication vehicle, one without compare anywhere on the planet (excepting of course those who believe in Cthuluh).
Everybody's been impressed by cephalopod camouflage capability, most by cephalopod intelligence, much fewer by cephalopod use of skin colour-texture-control to communicate, and fewer still by the incredible and mysterious cephalopod ability to learn. One might say these ancient creatures ( today's squids, octopuses, cuttlefish and nautiluses) were the first truly intelligent beings on Earth. How is it they can learn complex behaviour in such a short lifespan---only a couple years for cuttlefish which demonstrate the most colourful and complex skin phenomenon of all cephalopods...how do they do it? Like their skin, their brains seem to have exceptional properties.
The skin colour-texture-changing mechanism is remarkable. All skins are naturally fascinating, but cephalopod skin takes the cake: a hierarchy of coloured pigments blinds embedded in translucent tissue and muscularly controlled with almost instant responsiveness by prodigious brains and eyes to produce infinite shades of vivid colour and texture. It boggles the scientific mind as to how these coordinated faculties evolved. No wonder fanciful fiction speculates and ET role.
With today's technology, the neural networking of biochemicals, the genetic encoding of such faculties and its potential for repurposing for human benefit, and any comprehension of this highly evolved complexity has awesome potential in fields from medicine to communications---totally awesome!
But, science and technology aside, all one has to do is look into a cephalopod eye (cuttlefish, you might have guessed, are my favourite peepers) to marvel at its beauty, and feel the sense that it is carefully looking back and thinking, and learning. Just by looking.
My favourite demonstration of cephalopod smarts is the famous security-cam capture of an octopus leaving its lab tank, sliming its way several feet across the floor, up onto the table with another aquarium tank on it, and into the tank where there was an edible creature---that got eaten by the sneaky octopus. It then returned to its own tank---and nobody would have believed, marine biology experts all, an octopus could even plan something like that, let alone do it, out of water too. Like, did it somehow calculate how long it could survive out of water? Couldn't it have safely waited in its own tank for breakfast? Was the laboratory menu that bad that it had to dine out?
I once found a bunch of dying paper Nautilii washed up on a beach after a storm.
I had to walk 4 days with a bag of their shells suspended from my neck down the front of my chest. Most uncomfortable walk I ever did.