Cephalopods

I can't stop thinking about Cephalopods.

It's ever since watching a programme on Channel 4 - Inside Nature's Giants: the Giant Squid.  The whole series has been utterly fascinating - one of my very favourite things on TV.

Whoops ... I've just lost half my readers.

"We want more Wormwood", they cry.

To which I can only respond "Patience, patience - this is high-quality stuff you're getting here"

So Cephalopods - octopus, squid, and cuttlefish. They're remarkable creatures. If there was ever a candidate for an alien lifeform,  you couldn't do much better than choose a squid (or maybe a nautilus)

Setting aside the fact that they use water to give a degree of rigidity to their bodies and discretely passing over the details of their bizarre sex lives,  the thing I find utterly wonderful about cephalopods is their ability to manipulate their appearance using both the colour and the texture of their skin.

Watch this, for example:



The sheer versatilty with which a cephalopod can change it's appearance is a marvel in itself but what I find really intriguing is how they work out what pattern to display. Do they have a look around and have a think about it?

They do have very advanced eyes (or some of them do at least) but they also have light-sensitive cells on their skin which raises the intriguing possibility that these sensors might be wired-up more or less directly to the cells responsible for changing colour. After all, why burden the brain with the task of maintaining an internal model of the body when you have a real body that can do the job directly?

So it seems plausible that cuttlefish might have light-sensitive cells on the underside of their bodies that control the variable-colour cells on their uppersides - more or less directly. But I have no idea whether or not this is true. If you're a cephalopod specialist and you happen to be reading this, please feel free to put me right.

And then there's the other thing: when a squid or an octopus is not pretending to look like the sea-bed it can use its body to display vivid patterns conveying aggression or sexual attraction. So assuming the camouflage function is more or less involuntary it must be capable of being overridden by an impulse to display something quite different.

The natural assumption would be to imagine that these kinds of impulses originate in the brain; but the cephalopod brain - or at least the bundle of tissue that scientists label as such - is a fairly insignificant affair. Could it be that in cephalopods the distinction between brain and body is somewhat blurred and that the functions - both voluntary and involuntary - that we normally associate with the brain are distributed throughout their entire bodies?

Challenging questions indeed; questions from which most people might quite understandably flinch; but no more challenging - let me assure you - than those tackled every single day here at the Omnivorist Institute.