The Octopus posesses a highly developed nervous system and they are the most intelligent of all the vertibrates.
Although they are deaf, they have excellent eyesight (with the resolution being nearly the same as that of a human eye) and this enables them to comprehend visual tasks, learn from experience and to store knowledge.
These are amazing abilities for a member of the mollusk family, of which there are over 100 different species of the order Octopoda. Their name means eight feet and their sizes range from The Giant Octopus who can grow to a whopping 7m from arm tip to arm tip right down to the tiny Californian Octopus that measures a mere 1cm long.
The Octopus has a soft body and eight tentacle arms. There are two rows of suction cups that run down each arm and if the octopus sufferers the loss of an arm, it will re grow one back over a period of time.
Octopuses can change color in the blink of an eye, blending so well with their backgrounds they're nearly invisible. This is a defense mechanism and works because the animals outer surface is dotted with a number of pigment cells that he can adjust to his surrounding area if he is suddenly disturbed of alarmed by a predator or he is stalking his prey.
They move about by sucking water into their body and then pushing it out, shooting the octopus backwwards.
Octopuses hunt mainly at night and its diet comprises of small crabs, clams, cockles and scallops, plus some types of snail, fish, turtles, and shrimp. It will also attack and eat other octopuses and scavenge dead material also.
The octopus will only usually emerge from its abode if it is hungry and will wait for an unsuspecting victim to come into its range of vision and will then hurry out, enveloping the prey with its web of arms. If no ready meal swims into view, then the octopus will actively search among the rocks with the tips of its arms, which are flexible enough to get into the smallest crevice or hole.
Octopuses have an "intelligent" sense of touch. The suction cups that run down each arm are equipped with chemoreceptors. This means that that the octopus can essentially taste whatever it touches. They use their arms to catch their prey and once they have decided that it feels good to eat, they kill it by biting it with their tough beak, and paralyzing their hapless prey with a nerve poison that also serves to liquefy the muscle tissue.
Once he has caught enough food, the octopus will go back to its lair and then wait 20 minutes to feed, probably because it may not wish to be harmed by its own poison. They feed by either sucking out the flesh or biting it into small manageable pieces, drawing the food into its mouth with its tooth covered tongue.
The partially digested food is combined with a proteolytic (digestive) enzyme so that the indigestible material can be discarded much the same way as a spider.
A 1 ounce Australian blue-ringed octopus has enough poison to completely paralyze 10 average size people. This poison is called tetrodotoxin and is incredibly toxic. It is the same type that can be found in the puffer fish, served in Japan as fagu.
The Octopus will protect its lair by piling rocks to block the front of it. They can live in any space under the rocks or crevices on the sea floor.
The den will provide a home that protects them from predators and the eggs that are laid by the mother octopus who does not eat for the entire incubation period and who will die shortly after their birth.
The numbers of these intelligent creatures are become extremely low, and in particular the Pacific Northwest tree octopus (Octopus paxarbolis) is being lobbied to be added to the Endangered Species list due to the destruction of its natural habitat by humans.
This includes the decimation of habitat by logging, suburban development and the transportation systems that effectively cut off access to the water. Predators such as house cats and natural predators, including the bald eagle also contribute towards the waning numbers of this beleaguered species.