The octopus (plural octopuses) is a soft-bodied, eight-limbed mollusk of the order Octopoda. Eight-armed mollusks, which include about 300 species. They are two-sidedly symmetrical animals, they have two eyes, a beak and a mouth located in a central point in relation to the arms. Their flexible body has great range of motion. To travel by retreat, the animal uses a siphon through which it ejects water; the head while swimming is in the front, raised. The siphon is also used for gas exchange. Octopuses have a complex nervous system, and most species have great eyesight. They are also among the most intelligent invertebrates, exhibiting the most complex behaviors.
They inhabit diverse regions of the oceans, including coral reefs, oceanic waters, and the seabed. Most species are characterized by rapid individual growth, early maturation, and short life. During the breeding season, the male fertilizes the female, then ages and dies. The female lays the fertilized eggs in the burrow and cares for them until the young hatch, after which she also dies.
Predator defense strategies include: sepia shedding, camouflage, and prevention, use of jet motion, and stealth. All octopuses have venom, but only Hapalochlaena can kill a person.
The giant Pacific octopus (Enteroctopus dofleini) is often cited as the largest known octopus’ species. Adults usually weigh around 15 kg (33 lb.), with an arm span of up to 4.3 m (14 ft).The largest specimen of this species to be scientifically documented was an animal with a live mass of 71 kg (156.5 lb.). Much larger sizes have been claimed for the giant Pacific octopus: one specimen was recorded as 272 kg (600 lb.) with an arm span of 9 m (30 ft).A carcass of the seven-arm octopus, Haliphron atlanticus, weighed 61 kg (134 lb.) and was estimated to have had a live mass of 75 kg (165 lb.).The smallest species is Octopus wolfi, which is around 2.5 cm (1 in) and weighs less than 1 g (0.035 oz).
*Fun Facts about Octopus*
- Octopuses have three hearts. One of them deals with pumping blood throughout the body. The second pumps blood through the gills. The third stops working when it is swimming. Because of this, octopuses tire quickly and prefer to crawl.
- About 300 species of octopus have been discovered so far.
- A newborn octopus is about the size of a flea.
- The oldest octopus fossil discovered is 296 million years old.
- Wrestling with octopus was a popular sport in the 1960s. The competition was based on a diver’s fight with an octopus in shallow water. There was even a world championship in this discipline in the United States.
- Live octopus is eaten in Korea. This “delicacy” is called sannakya.
- They do not have 8 arms at all, but 6 arms and 2 legs.
- Hapalochlaena is the most dangerous type of octopus. They can kill a person with a single prick.
- Octopuses prove that it is not size that matters. Their brain size is comparable to that of a walnut. They are considered the most intelligent invertebrates.
- A hungry octopus can eat its own arms.
- They live relatively shortly. Some species only reach six months of age. The largest ones can survive 5 years.
- The mimetic octopus can look like 15 other marine animals, such as snakes and rays. It was discovered in the mid-1980s by photographers.
- They move with elegance, but unlike most animals, their movements do not have a rhythm.
- The largest documented octopus weighed 71 kg.
- Large octopuses can catch and kill certain types of sharks.
- Animals have chemoreceptors in their suction cups. Thanks to them, they can feel the taste when touched.
- Octopus skin can change its color 177 times an hour.
- All species of octopus are poisonous to humans. Only one of them is a deadly threat.
- One method of defending against a threat is blending into the environment. Another skill is changing the color or spraying a black substance.
- The giant octopus is the largest species. Its tentacles are up to 4 meters long.
- The taste of octopus is like that of chicken meat.
- Octopuses are cephalopods with eight arms
- The first octopuses appeared on earth about 323 million years ago.
- Due to the soft body of these organisms, not many octopus’ fossils are found.
- Octopuses live in every ocean.
- They live in different habitats depending on the species. Some of the octopuses live in the deep ocean and can be found at depths of 1,000 meters. Others, in turn, inhabit coral reefs or shallow tidal pools.
- Most octopuses have great eyesight. Octopuses have two eyes, one on each symmetrical body part. The color differentiation of these animals varies from species to species.
- There are octopus’ species that are practically blind. Individuals with this trait are, for example, representatives of the species Cirrothauma murrayi.
- There are round suckers on the inner surfaces of the octopus’ arms. They use the phenomenon of adhesion to grasp objects or manipulate them.
- In both octopuses and cuttlefish, the ratio of the weight of the brain to the rest of the body is the highest among all invertebrates.
- 2/3 of the octopus’ neurons are in the nerves of the animal’s arms.
- The motor skills of these cephalopods are not managed by the brain, but by their unique nervous system located in the legs.
- Octopuses have 3 hearts. Their circulatory system is a closed system in which there is one systemic (main) heart, pumping blood through the animal’s body, and 2 gill hearts, which are used to pump blood through the gills. The octopus’s systemic heart consists of one chamber and two atria.
- During swimming, the systemic heart stops working. This causes the octopus to tire quickly and therefore these organisms prefer to move along the bottom with their arms.
- Octopuses have the so-called siphon, i.e. the body responsible for gas exchange, removal of metabolic waste and the release of ink.
- Octopuses swim, throwing water under pressure through the siphon.
- Octopuses can also breathe through their skin, which in these animals is very thin. According to research, while the octopus is resting, up to 41% of its oxygen demand can be covered by skin respiration.
- In the mouth of octopuses there is a grater called a radula. Radula is made of chitin and its task is to crush the food that has entered the mouth.
- The mouth of octopuses begins with a beak that is characteristic of these animals.
- Most octopuses are predators. They feed mainly on crustaceans and polychaetes, although they do not despise other mollusks. The octopus’ menu also includes shrimp and fish.
- The giant octopus eats mainly mussels and crabs. When hunting crustaceans, octopuses paralyze them with their saliva and then break them up with their beak.
- The protein hemocyanin is responsible for the blue color of the blood of octopuses.
- The octopus’ renal counterpart is called nephridia.
- Octopuses have a so-called blackberry pouch. This organ stores the sepia produced by a nearby gland. Octopuses use sepia to confuse the predator while escaping. Then they spray a thick, characteristic black spot.
- Most octopuses live for only a few months, usually six months. After the hatching of the offspring, the octopus dies of hunger because after the breeding period in these animals the digestive glands are deactivated.
- The life span of octopuses is directly influenced by the optic gland. During research on octopuses, their optic glands were removed, and as a result, adults stopped guarding their offspring, started eating again, and their life expectancy increased significantly.
- During mating season, octopuses may change skin color to signal their mate to mate.
- Female octopuses can lay 10,000 to 70,000 eggs after fertilization. They place them in rock crevices in the form of special egg ropes. The eggs are then guarded for approximately 160 days, when the young octopus hatch. Octopus eggs can take up to 10 months to develop in colder waters.
- Most octopuses hatch from eggs as paralarvae and function as plankton for the first weeks or months. These tiny octopuses feed on zooplankton, arthropod larvae, or copepods.
- Octopuses are highly intelligent. In studies with these animals, both short-term and long-term memory were found.
- Each octopus must gain experience on its own, because they are left by their parents immediately after hatching.
- The largest representative of the octopus is the giant octopus. It was first described in 1910. The largest of the encountered octopuses of this species weighed 272 kilograms and had 9.6 meters of arm span. The giant octopus is also one of the longest-lived octopuses, it can live up to 5 years.
- The world’s smallest octopus is the Octopus wolfi. Representatives of this species are approximately 2.5 cm long and weigh 1 gram.
- Some octopuses use the phenomenon of bioluminescence to lure their victims. To do this, they use organs called photophores, which are located inside the suckers.
- From ancient times, octopuses were considered sea monsters. They appear in Norse mythology as Kraken or Gorgons in Ancient Greece.
- Most octopuses live solitary lives, but we also find species that live in larger communities.
- Some octopus species, when attacked by a predator, may throw away the arm from their body, which by crawling along the bottom distracts its attention.
- Octopuses of the species Thaumoctopus mimicus can use their flexible body and change the color of their skin to resemble other, more dangerous marine animals.
- Octopuses of the species Amphioctopus marginatus collect coconut shells and use them to build their hiding places.
- Octopuses can camouflage themselves. Thanks to the special cells in their skin, they can, like a chameleon, adjust their skin color to the environment. Camouflage is used by these animals both for hunting and hiding from predators.
- In the Mediterranean and coastal areas of Asia, octopuses are food for humans.
- According to the Hawaiian creation myth, the modern cosmos is the last of the debris of previous universes and octopuses are the only survivors of the previous universe.
- Aristotle was already observing octopuses. He noted that they had the ability to change the color of their skin and identified their sexual organs.
- According to the World Animal Foundation, octopuses have an excellent sense of touch. Their suckers have receptors that allow octopuses to taste what they touch.
- The octopus’ ink does not hide the animal. Ink physically harms enemies. It contains a compound called tyrosinase that helps control the production of the natural pigment melanin in humans. But when it is sprayed over the eyes of a predator, tyrosinase causes a blinding irritation.
- Octopuses have blue blood. To survive in the deep ocean, octopuses have evolved. This copper base is more efficient at transporting oxygen than hemoglobin when the water temperature is exceptionally low and little oxygen is around. But this system also makes them extremely sensitive to changes in acidity.
- Most octopuses – those of the Incirrata (or Incirrina) suborder – have no internal skeletons or protective shells. Their bodies are soft, which allows them to compress into tiny cracks and crevices.
- Octopuses have a mind of their own. Two-thirds of the octopus’ neurons are in his arms, not his head.
- When an octopus is swimming, the organ that supplies blood to the organs stops beating. This exhausts the octopus, which is probably why they prefer to crawl rather than swim.
- Octopuses are highly intelligent animals, masters of camouflage, who have evolved a variety of tricks over tens of millions of years to avoid or frustrate potential attackers. They can match the colors and even the textures of their surroundings, allowing them to hide from predators. It can also get away quickly.
- Their soft bodies mean that octopuses can fit into little nooks and crannies, if the holes are not smaller than the only hard part of their bodies: their beaks.
- Octopus arms are lined with hundreds of suction cups, each of which can be moved independently thanks to a complex bundle of neurons that act like the brain, allowing the animal to touch and manipulate objects.
