The Octopus is a very unique animal. The word Octopus actually means 'eight feet'. The octopus has eight tentacles dangling from its body. It has large eyes. There are about 150 to 200 species of octopuses. Octopuses have short lives. Many live one year or less. Only the largest species live about three years. Mostly, its habitat is in rocky, sandy or muddy bottoms in oceans throughout the world. The other remaining octopuses live deep beneath the sea level. The octopuses have many different sizes. The giants weigh about 110 pounds and measures more than 20 feet. They are found in the Pacific Ocean. The tiny ones are greatly found in the Indian Ocean. They are only 1 inch tall and they weigh less than 1 ounce. There is a special kind of octopus that is called the Blue-Ringed octopus. It is the only type of poisonous octopus and it lives in the tropical areas.
Octopuses have blue blood. The blood is blue because they use an oxygen-carrying molecule in their blood that contains copper. That is really amazing. The body of an octopus is soft and boneless. A fleshy covering, called the mantle, surrounds the main part of the body. It forms a cavity that protects the gills. An octopus breathes by drawing water into the cavity. The circulation of water gives oxygen for the gills. The mantle then forces the water out through a tube called the funnel or it is also named siphon. An octopus has three hearts. Two hearts are combined with the gills and are called the gill hearts.
The two eyes of an octopus are on each side of the head. They are the same as the eyes of human beings and gives marvelous vision. Eight arms stretch from the head of an octopus. At their base, a membrane web unites the arms. At the bottom of each arm, there are muscular suckers. The common octopus has about 240 suckers on each arm. They work like small suction cups. The really good thing is that if an octopus loses an arm, a new one grows at the same place.
An octopus's mouth is located under the head at the base of the arms. When an octopus leaves its den to hunt for food it uses its keen, sharp eyes. The octopus sometimes crawls on the rocks and suckers helping it to push forward looking for something to eat. It may also jet through the water by shooting out water from a tube, the funnel. A unique way the octopus captures its prey is when the octopus waits in its den and if it sees a meal passing by, it will grab it. When the octopus has almost caught its prey, it will float down and wraps itself around its prey using its arms. Octopuses mostly eat crabs, clams, and snails. Many species also eat other octopuses! The octopus holds its food with the suckers and looks at it to make sure it is all right. The octopus then carries its food to the mouth. The octopus has a curved beak inside the mouth and the octopus uses it to crack the shell of its catch. Afterward, the octopus injects a poison from an organ of its mouth. This will make it much easier for the octopus to eat its prey. When the animal is fully paralyzed or dead it devourers its food. To drink water, it will take in water into the cavity of the mantle, remember that it will also use it to get air.
Lots of sea animals, especially seals, whales, fish and moray eels prey on octopuses. Even many species of birds capture octopuses to eat. An octopus has many ways of escaping from predators. The octopus does not have bones or a hard shell, so it can easily squeeze itself into a very tiny space between rocks to avoid its predators. If it is not near a rock, it is in trouble. But still the octopus may let out inky fluid to hide itself. Sometimes, the shape and the smell of the ink cloud could be the same of the octopus so it will trick the predator. When that happens, the animal will attack the fluid. By then the octopus would have swam quickly backward by forcing a powerful jet of water through its funnel. This is called propulsion. An octopus can also defend itself by camouflaging. An octopus can escape danger from its enemies by quickly changing colors to confuse the predator. Its skin contains of special cells called chromatophores. Each cell has one color. When an octopus is frightened, these cells expand so the skin color changes and by that it can shock its predators by blending in with its surroundings. Colors might also show according to their feelings. Like angry ones turn red and frightened ones turn really pale. Another way it can camouflage is when its skin changes compared to its surroundings. Like if it is on seaweed, its skin will be bumpy and if it on the sea bottom, the skin will probably turn soft. Octopuses are also a main source of food to humans. The main places to harvest octopuses are off Japan, the Mediterranean and off the coast of Africa. They sometimes use the octopuses' ink to color black pasta.
Octopuses reproduce sexually. Octopuses, like humans, mate any time of the year. The female octopus can lay more than 100,000 eggs. When a mother lays her eggs, she lets them hang off from the roof. It looks like bunch of grapes hanging off of a tree. While the eggs slowly grow, the mother never eats or rests. She cares about the eggs until they hatch into tiny octopuses. After the eggs turn into little babies, the mother dies. The young swim at or near the surface of the water for several weeks like plankton. Many of the young are eaten by fish and other marine animals. The remaining young octopuses go to bottom of the ocean and develop into adult octopuses. Some species lay very large eggs. Due to this, the young babies in those species instantly go to the ocean bottom after hatching.
Octopus plays a dominant role in the environment. Since octopus takes different kinds of food it does not cause extinction of a particular species. Also not a single predator in the ocean is solely dependent on octopus for its food. Thus octopus plays an active role in the ocean.
Whew, good adventure, was it not? That was really cool. I learned tons of great stuff. That was really cool. Now we know that the wondrous sea has the most interesting animal, the amazing OCTOPUS!