I know this is probably extremly late in the discussion, but I am absolutely fascinated with this whole thread! I've been interested in marine life since I was a kid and I've always loved cephalopods the most. I guess I'll fill all that in when I fix up my profile.
To get to my point. I currently work for an aquatics distributor, and previously I worked in a aquatics retail store. When I worked at the store we came across the well known blue ring...pymgy variety. My boss, knowing my love for cephs, and also knowing the dangers involved with this particular species knew I was distraught since my little buddy, an unidentified octopus a customer brought in, was murdered by two crabs. (I think an associate of mine did it to spite me) We constructed a tank for the blue ring, of course making sure it was safe where no one could touch it.
To get to the point, even though it was a pygmy, it's ability to change shape, more pointedly to extend it's body to almost the size of my hand shows that it was a master of mimicry. Also for any who may not know, Blue Rings generally do not look like their famous relative in Double O 7 ^_^. When feeding, it (I do not know enough to determine male from female >_