Feelers said:And this doesnt explain how a blind octopus can match its surroundings. Also I was under the impression that a severed arm would also match its' surroundings, not sure on either of these facts,(I read them somewhere) can anyone confirm if they are true?
Jean said:From what I understand, although most cephs can't see colour, they can discriminate (to a very fine degree) the differences between hue and colour intensity (and patterns but that's another story!). I watched a Discovery doco which had John Forsythe demonstrating that a cuttle can match patterns based on colours of different intensity BUT when he put the cuttle in a tank with a substrate of yellow tiles and green pebbles which had the same intensity the cuttle didn't change. The other was put in a tank with (I think) red tiles and blue pebbles and the cuttle opted for a checkerboard pattern. The tanks were then filmed in black and white and to our eyes (well mine anyway!) the red and blue were different shades of grey and the yellow and green were all one shade of grey! So cephs may have a better ability to match based on tone, hue and intensity.