Octopus :252 species of marine molluscs in 26 genera of the octopus family. It is the largest family of cephalopods and can be divided into the bathypolypodinae subfamily, the eledoninae subfamily, the graneledoninae subfamily and the octopodinae. The body is ovate or ovate, muscular, the mantle cavity is narrowly open, and the body surface is generally free of water holes. Wrist suction cups 1 or 2 columns. Males have left or right 3rd carpal stemming, with a seminal groove on the ventral margin of the wrist and a spoon-shaped tongue leaf at the end; the stemmed wrist cannot self-break. Funnel coat lock degenerate. With 1 pair of vestigial needle-like inner shells or no inner shells. If there is a toothed tongue, the lateral teeth of the tooth tongue are generally single-pointed. The stomach and cecum are located behind the digestive glands.
This family is an important commercial cephalopod, and there are certain productions of true slugs (common octopus) along the southern coast of China and short slugs along the northern coast. The dried products of the grubs are called "eight dried slugs" or "dried octopus", in addition to eating, in medicine, there are still blood tonic qi, astringent muscle effect.
It is a temperate mollusk, living underwater, adapting to water temperature can not be less than 7 ° C, the proportion of seawater 1.021 is the most suitable, and the environment with low salinity will die. It can feed on large animal plankton and grow. It is widely distributed in the tropical and temperate waters of the world's oceans.
There are more than 252 species of marine molluscs in 26 genera in the octopus family, and their sizes vary greatly. The octopus body is short ovoid, sac-shaped, without fins; the division between the head and the body is not obvious, the octopus has a head carcass of about 7-9.5 cm, and has a large compound eye and 8 retractable wrists on the head. Each wrist has two rows of fleshy suction cups, the wrist length of the short slug is about 12 cm, the wrist length of the long slug is about 48.5 cm, and the wrist length of the true slug is about 32.5 cm. Usually crawling with the wrist, sometimes using the inter-carpal membrane to stretch and contract to swim, can hold other objects strongly, and spray water with the funnel in the lower part of the head for a quick retreat. The base of the wrist is connected to a web-like tissue called a skirt, which has an opening in the center. The mouth has a pair of sharp palates and a file-like tooth tongue that is used to drill through the shell and scrape its flesh.
The most well-known octopus in this family is the common octopus (o. vulgaris ) is medium in size , widely distributed in tropical and temperate waters around the world , inhabiting caves or crevices on the rocky seabed . This species is considered to be the most intelligent of the invertebrates, with highly developed pigmented cells that can change body color extremely rapidly. The smallest octopus is the Atlantic pygmy octubini ,about 14 cm long; the Atlantic pygmy octopus is powerful, and a suction cup of about 2.5 mm in diameter on the wrist can hold objects weighing 48 grams. The largest octopus is the North Pacific giant octopus dofleini, which in February 1973 was caught by a diver in Washington's Shahoud Canal, which reached a diameter of 15.6 meters and weighed 53.6 kilograms when the brachiopods were unfolded. The octopus is 1.5-2 meters long, the suction cup diameter is about 6 mm, and the suction gravity is more than 100 grams. They can often tow large stones that are 5, 10, or even 20 times heavier than they are.
Not only can an octopus spray ink six times in a row, but like the most flexible chameleon, it can change its color and structure like a stone covered with algae, and then suddenly pounce on its prey, which has no time to realize what is happening. Octopuses can use flexible brachiopods to crawl between reef rocks, crevices and seabeds, sometimes disguised themselves as a bunch of coral, and sometimes as a pile of shiny gravel. Mark Norman of the University of Melbourne, Australia, discovered in 1998 an octopus in the estuarine waters near the Indonesian island of Sulawesi that can quickly mimic poisonous creatures such as sea snakes, lionfish and jellyfish to avoid attack.
Octopus is a temperate mollusk, living underwater, adapting to water temperature can not be less than 7 ° C, the proportion of seawater 1.021 is the most suitable, low salinity environment will die. The bottom of the sea area is preferably a gravel zone, the water temperature is above 12 ° C, the total length of the hatchlings is about 3 mm, it can feed on large animal plankton and grow, after 45 days, when it is 10-13 mm long, it settles in the benthic life of the submarine camp, and if there is no ceramic clay pot conch shell to be used as a living room, it will build the house by yourself.
food
Carnivorous, feeding on gills and crustaceans (shrimp, crabs, etc.), some species eat plankton. It's not a matter of whether it likes it or not, because stable structural myoglobin is a necessary condition for octopus to survive in the deep sea, and it fights with lobsters to fight for astaxanthin (astaxanthin in English, referred to asta) resources, astaxanthin is the strongest antioxidant, is a necessary condition to ensure that the structure of myoglobin is stable and not oxidized. According to Professor Francesco Buda and his experimental team members at Leiden University in the Netherlands in 2008, through accurate quantum computing, it was found that cooked shrimp, crabs, salmon as representative fish showed a seductive bright red color, because shrimp, crabs, salmon as representative fish are rich in astaxanthin, and the natural red substance of cooked shrimp, crabs, salmon as representative fish is astaxanthin.
behavior
The octopus sucks water into the mantle membrane and after breathing, expels the water through a short funnel-shaped body tube. Most octopuses crawl along the coastal bottom with suction cups, but when frightened, they will spew water streams from the body tube, and the water jet is strong, so that they quickly move in the opposite direction. When encountering danger, an ink-like substance is sprayed out as a smoke screen. Some species produce substances that paralyze the sensory organs of the attacker.
In order to avoid the hunting of "predators", in addition to the well-known mimetic camouflage and "wrist" self-preservation technique, American scientists have also found "high-IQ" octopuses that can use bipedal "walking" to escape in the Indian Ocean. Christine Hefard of the University of California, Berkeley, and her research team photographed an octopus called Marginettes in tropical Waters, about the size of an apple, and when faced with danger or encountering a diver, the octopus would bend six of the eight "claws" upwards and fold upwards to make the appearance of a coconut shell, while the remaining two "claws" would stand on the ground on the seabed, secretly moving backwards, like a small coconut that would move, fleeing in a backward stride, and the posture was very funny.
Another walnut-sized Akulettes octopus also walks on two legs, although the other six legs stretch outwards to simulate the appearance of seaweed. The team found that walking with brachiopods far exceeded that of octopus, with the former having a maximum speed of about 0.14 meters per second.
hobby
Octopuses have a penchant for utensils and are eager to hide in hollow vessels. The octopus not only loves to drill bottles and cans, but every container, it loves to burrow into and shelter. A large bottle with a volume of 9 liters and a diameter of less than 5 centimeters was found in the English Channel, and an octopus more than 30 centimeters thick was found inside; in the cargo compartment of an ancient Greek shipwreck found not far from Marseille, France, it was filled with amphora and large water tanks for noodles, and almost every one of them contained an octopus. The collapse of the 3-story ship provided thousands of good homes for the octopus. For more than 2,000 years, octopuses have lived in such shipwrecks for generations. After the crashed plane sank to the bottom of the sea, the gasoline tank also provided shelter for the clever octopus. Even the skulls of people fished out of the Mediterranean harbor an octopus.
In view of the octopus's penchant for drilling utensils, people often catch octopus with crock pots, bottles and fishing gear. Japanese fishermen sink clay pots of various shapes to the bottom of the sea every morning on long ropes. After a while, the fishermen will bring up the clay pots, and at this time, as long as a little salt is sprinkled into the jars, the octopus that stubbornly refuses to come out of the jar will come out. Indian fishermen take the same approach using large conch shells. They often weave eight or nine hundred large sea snail shells into a catch net, and can catch two or three hundred octopuses a day. Cuban fishermen use wind snail shells to trap octopuses. Tunisian fishermen throw drainage pipes to the bottom of the sea and can catch octopuses.
mimicry
On the surface of the octopus is a type of cell called chromatophores. Each pigment cell contains one of four natural pigments: yellow, red, brown, or melanin. These pigments can only be seen if the pigment cells contract. Octopuses can change their color by shrinking only one type of pigment cell at a time. It can also dodge predators in camouflage, and can also catch prey by taking on the same color as clear water, sandy seabeds, or black rock crevices. When an enemy is approaching, the octopus will turn dark pink, release a cloud of black ink (called sepia) from the ink sac, then fade in color and quickly flee. [6]
thinking
Jim Cosgrove, an expert on octopus research for many years, points out that octopuses have a "conceptual mindset" and can solve complex problems on their own, and it is this ability to walk on two legs. Jim Cosgrove wrote in the French magazine Figaro that octopuses are one of the most different creatures that have ever appeared on Earth that is different from humans. The octopus has very developed eyes, which is the only similarity it has with humans. It is very different from humans in other ways: octopus has three hearts, two memory systems (one is the brain memory system, the other is directly connected to the suction cup), the octopus brain has 500 million neurons, and some very sensitive chemical and tactile receptors. This unique neural structure gives it a thinking ability that exceeds that of ordinary animals.
Scientists once tested octopus: scientists put a glass bottle containing lobsters into the water, but the bottle mouth was blocked by a cork. The octopus circles the bottle a few times and then wraps it around with its tentacles, and then through various angles, uses the tentacles to tease the cork and finally successfully pulls it off, allowing for a full meal. The study believes that the experiment shows that octopuses are able to solve complex problems on their own, that is, have what is called "conceptual intelligence". After further research, the scientists also found that octopuses have lived alone since they were born. Small octopuses can learn their skills in a very short time, and unlike most animals, the learning of small octopuses is not based on the teachings of their elders. Although their parents have inherited some abilities, the baby octopus develops its ability to solve new problems by learning to hunt, camouflage, and find better shelter on its own.
The "brainy" octopus has also caused uneasiness among scientists. "This discovery greatly enriches the human understanding of octopus behavior, and it is also very enlightening, because it proves that it is entirely possible that octopuses can walk in other ways, or that there are other animals on the seabed that can also walk on two feet," Hefad said. Scientists in Australia have confirmed that the eight-legged species is capable of moving coconut shells and using them as their own armor. This is the first case of invertebrates using tools. Understanding exactly how octopuses control and coordinate the other eight soft brachiopods can help engineers design more agile robotic arms or brainless robots.
The breeding time of octopus in the ocean is generally concentrated in the spring and autumn, and the water temperature in the spring and autumn is about 16 °C. Octopus likes to spawn in the shell of the snail, so it can be used to sink into the seabed through the red shell with a rope and be retrieved and caught on time. In autumn and winter, they often burrow in the sediment of deeper seas.
Octopus hermaphrodite. The male has a specialized wrist, called a stem wrist or handover wrist, to place the spermatozoic directly into the female's coat cavity.
During the breeding season, female octopuses spawn, about 0.3 cm long and totaling more than 100,000, under rocks or in holes. During incubation, the female guards the egg, cleans the eggs with suction cups, and stirs the eggs with water. Female octopuses need to hatch after 4-8 weeks after one-time spawning. The juvenile octopus is shaped like an adult and small, and after hatching, it needs to drift with plankton for several weeks before sinking to the bottom of the water for concealment.