Cephalopod intelligence
The study of cephalopod intelligence also has an important comparative aspect in the broader understanding of animal cognition because it relies on a nervous system fundamentally different from that of vertebrates.
In spite of this, the existence of impressive spatial learning capacity, navigational abilities, and predatory techniques in cephalopods is widely acknowledged.
[7] Cephalopods have large, well-developed brains,[8][9][10] and their brain-to-body mass ratio is the largest among the invertebrates, falling between that of endothermic and ectothermic vertebrates.
[10][12] The giant nerve fibers of the cephalopod mantle have been widely used for many years as experimental material in neurophysiology; their large diameter (due to lack of myelination) makes them relatively easy to study compared with other animals.
[14] Crabs, the staple food source of most octopus species, present significant challenges with their powerful pincers and their potential to exhaust the cephalopod's respiration system from a prolonged pursuit.
At least four individuals of the veined octopus (Amphioctopus marginatus) have been observed retrieving discarded coconut shells, manipulating them, transporting them some distance, and then reassembling them for use as shelter.
[39]) Octopuses have also been known to deliberately place stones, shells, and even bits of broken bottles to form walls that constrict their den openings.
[41] Smaller individuals of the common blanket octopus (Tremoctopus violaceus) hold the tentacles of the Portuguese man o' war (whose venom they are immune to), both as means of protection and as a method of capturing prey.
[42] The highly sensitive suction cups and prehensile arms of octopuses, squid, and cuttlefish allow them to hold and manipulate objects.
However, unlike vertebrates, the motor skills of octopuses do not seem to depend upon mapping their body within their brains, as the ability to organize complex movements is not thought to be linked to particular arms.
[43] Cephalopods can solve complex puzzles requiring pushing or pulling actions, and can also unscrew the lids of containers and open the latches on acrylic boxes in order to obtain the food inside.
