More strange facts about octopuses

From the Guardian 16th May: by Ian Sample, edited by me:

Octopuses can regrow limbs lopped off by predators and mean scientists.

"~But for all their impressive feats, the octopus's walnut-sized brain cannot keep track of what its eight arms are doing. The problem is too hard. Since each arm is studded with suckers that act on contact, the mystery is this: how do octopuses not get tangled up in knots?

Researchers in Israel set out to answer that questions in a series of experiments that grew steadily more gruesome..

The limbs are intriguing for roboticists, because they are autonomous: none knows what the others are doing, and they make many of their own decisions. Of the octopus's 500 million nerve cells, more than half are in their arms.

...The arms can survive for around an hour after being amputated. Lone limbs have been seen to grab food and even pass morsels to where the arm thinks its owner's mouth must be.

It was a student of Hochner's who first noticed octopus suckers attached everything but octopus skin. ... On more that 30 occasions, Hochner noticed that amputated arms never latched on to themselves. ... The only time one amputated arm grabbed old of another was when the latter was peeled. [Urggghh]

Presented with dismembered arms, some octopuses grabbed them as if they were lumps of food , and brought them to their mouths. They were less likely to do so if the amputated arm was one of their own.

The scientists now want to learn which chemical is responsible for blocking the suckers, and how the animals can tell their own flesh from that of others.

Under water to get out of the Rain part 3 - Fishing for Octopus

did 4 lesson plans today and I am now confused as to which class is going to learn what and which books are involved. So back to reading for light relief.

The octopus has a flair for inciting repugnance. It changes its texture and colour to impersonate boulders or weed or a slither of slime without substance. Even slime doesn't take this as a compliment. ... Quick as a whip, its arm embraced me, then another and yet more. they could do eight unpleasant things at one. Pulling them off felt as if they were taking my flesh with them.

The octopus is an Einstein among invertebrates. Even hardened researchers recount that they are quick to learn, they come to be fed and their gaze follows you around the room. At least, one of their eyes does because some are right-eyed, others left-eyed. The structure of the octopus eye is almost exactly the same as ours and it is difficult to gaze into it without thinking that a human being is trapped inside. It has the look of sad acceptance of someone transformed into a bag of jelly by witchery and condemned to unhappy octopusdom for ever. 

..He inserted the wire into its mouth and out through the top of its head. It stared at me in sad surprise, as if asking what was I going to do about it. Eventually, seven or eight were skewered on the wire, stacked one about the other, still half alive and pathetically waving goodbye.

This is another creature: the mimic octopus, which I found just now on YouTube. I had never heard of it before; it is very gifted and talented.