The octopus belongs to a subclass of cephalopods. They are symmetric, with two eyes and four pairs of the arms (the reason they have got the title octopus, which means eight). Despite the fact that the octopus is a cephalopod, it’s very different from its relatives such as oysters and snails. It’s more closely related to the squid.
The octopus doesn’t have a shell; it has a hard beak, with its mouth in the centre. As they don’t have a skeleton they can squeeze through narrow places and their favorite location is coral reefs.
If you meet an octopus under the water, then move away as quickly as possible. They might not look dangerous, but there is one type of octopus, the blue ringed octopus, which can be deadly. The octopus can change its color from red to gray, yellow, dark or greenish. At their back they have a type of muscular siphon. Water comes in the siphon, and the octopus takes the oxygen from it. The octopus expels a strong jet of water, which helps it to bounce back. In that manner, the octopus can run away from a predator which has come too close.
The octopus moves by swimming and crawling. When they would like to travel slowly, they tend to crawl with a pool. When they are helped by the jet propulsionthey move really quickly, but even then they use swimming and walking.
When they crawl, they actually walk their arms. Normally they use many legs at once, on soft and solid surfaces. Recent study from 2005 revealed that some octopus can walk on two arms.
This way of moving (locomotion) helps octopus to flee from a potential predator. However, moving helps the octopus to capture its prey also. The octopus eats mainly fish and goats, but when it’s hungry it catches everything.
For ingestion, the octopus uses its powerful jaws, which resembles the beak of a parrot. It can bite strongly and at precisely the exact same time that it injects its poison. The poisonous liquid helps it in disabling its prey and its long arms, although they make the octopus look unusual with its suck holes, it is with these it grabs its prey and squeezes it securely.