1. The octopus is a mollusk. It is also an invertebrate, which means it has no bones in its body. The octopus also belongs to a sub-species of mollusks called the cephalopods. This means “head to foot” and is used as the name because an octopus’ "feet" are attached to its head.
2. The octopus can only be found in salt water, but they live in all the oceans. The octopuses that live in warm waters tend to be small. The ones that live in colder waters are much larger. The octopus has a life span of 1 to 2 years.
3. There are about 300 known species of octopus.
4. The body of an octopus looks like a bag. It also has a bulbous head, large eyes, and eight arms. The arms of the octopus have suckers. The arms also have many nerves which allow the octopus to grab and taste things. The octopus has excellent eyesight, but they are deaf. The octopus has three hearts. The blood of an octopus is light blue. The octopus is considered the most intelligent of all the invertebrates. The octopus has a beak around the mouth.
5. The octopus can grow to about 4.3 feet (1.3 meters) in length and weigh up to 22 pounds (10 kilograms), although the average octopus is much smaller. The Giant Pacific Octopus lives in the coastal waters off of British Columbia and is the largest octopus in the world. The largest one caught weighed 600 pounds and its tentacles spanned 33 feet.
6. When a female octopus lays eggs, it takes about a month for the eggs to mature and hatch. The female guards her future offspring the entire time. Because she is not hunting during this time, it’s common for the female to become extremely weak and die of starvation around the time that her young are hatching. Because of the limited time spent with their parents, young octopus learns almost nothing from their parents.
7. The body of the octopus moves as the octopus breathes. The octopus moves by forcing water out of its body through a tube. The force of the water will send the octopus backwards very quickly. If they are threatened by a predator, they will force water out of this tube with a great deal of force, almost as if they have jet propulsion. The octopus can also protect itself by squirting an inky substance at a predator, temporarily blinding it. The ink also dulls the predator’s sense of smell, which makes it harder to find the fleeing octopus. The octopus can also blend into its surroundings, which allows it to hide from predators. The body of the octopus can also squeeze through very small cracks, which helps them to escape a situation that is threatening. If the octopus is caught, it can give up an arm to the predator and grow it back. The octopus also has beaklike jaws that can deliver a nasty bite. The saliva of the octopus contains venom, which makes it poisonous.
8. Some octopi will collect crustacean shells and other objects to construct fortresses, or "gardens," around their lairs.
9. The octopus preys on crabs, crayfish, and mollusks, and will sometimes use their ink to disorient their victims before attacking. They hunt mostly at night. Octopi have great problem-solving skills and can often figure out how to escape even the most secure fish tanks. They have even been known to climb on board of fishing vessels and open holds to feed on crabs.
10. The blue-ringed octopus is one of the most popular species in home aquariums because of their beauty and small size. They are also one of the most poisonous animals on earth! Though the blue-ringed octopus is merely the size of a golf ball, its venom can kill a human being. humans.