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.
No comments:
Post a Comment