Octopuses are found in every ocean in the world and there are about three hundred known species. They only live in salt water. Octopuses who live in warm water are usually smaller than the species who live in cold water. The largest species of octopus is the Giant Pacific Octopus. The largest one ever caught weighed approximately what a brown bear weighs. Octopuses have eight arms. They are attached to its head near the mouth. Along the arms there are suckers which are used to grab as well as taste and feel. An octopus has three hearts and is the most intelligent of invertebrates. Their blood is a light blue color. They also have outstanding eyesight but are deaf. They get around by swimming, crawling or jet propulsion. Jet propulsion is the fastest of the three and allows them to travel over long distances.
One of the most interesting things about octopuses is the way in which they defend themselves against predators. Octopuses, like chameleons, are able to change their color and even their skin texture to blend into their surroundings so their enemies can’t see them. Such enemies include sharks, dolphins and eels. Octopuses can further obscure themselves by squirting ink at an attacker. This dark ink makes an attacker unable to see the octopus, allowing the octopus time to get away from the threat. Further, the ink interferes with the predator’s ability to smell, which can further throw off predators, like sharks, who rely on their sense of smell to hunt. Because octopuses have no bones, they are able to squeeze their bodies through tiny openings, such as between rocks, that their enemies can’t fit into. This is a great means of escape for them. Their final defense mechanism is that if a predator grabs one of its arms, an octopus can detach itself from its arm and get away. The octopus will later regrow the limb, with no lasting ill effects.
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 humans. Before going after its prey, an octopus may spray its ink to disorient them. Octopuses eat shellfish, such as crabs, as well as mollusks and hunt mostly at night. Octopuses 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.
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 learn next to nothing from their parents.