As for the females, they can lay up to , eggs, which they obsessively guard and tend to. Prioritizing their motherly duties, females stop eating. Her body undertakes a cascade of cellular suicide, starting from the optic glands and rippling outward through her tissues and organs until she dies. Check out Octopus! Octopus has been a popular food item in East Asia, Spain, Greece and other countries for centuries, and recently, it has gained popularity in the U.
Today, Koreans consume the most octopus. But that popularity has had an impact on octopus stocks in oceans around the world. In Japan, for example, octopus catches plummeted by 50 percent between the s and the s. The international demand for octopus inspired North and West African fisheries to start targeting the animals in the 80s, although recently demand has taken a toll on those waters as well, shifting fisheries from Morocco to Mauritania and, more recently, Senegal.
According to the U. Food and Agriculture Organization , around , tons of octopus is imported by various countries around the world each year.
The third heart called the systemic heart , then pumps the oxygenated blood through the rest of the body. Each heart of the octopus is not like a substitute or reserve heart. The three hearts actually work at the same time to pump blood through each the gills and around the body. Regardless of this, the octopus does not need all three hearts to survive. It can live with less than all three of its hearts.
Exactly how many of the three hearts can an octopus survive on? Can an octopus survive if one heart is bad? The answer depends on one which of the three hearts is not working. Remember, the octopus has one heart near each of its two gills that pump blood through the gills. The two gills are like human lungs, and when blood passes through them, the blood absorbs oxygen from the gills. Even humans can survive on one lung.
Add to this the fact that an octopus also absorbs oxygen through its thin skin. An octopus with two hearts may be a lot less active than normal, but it will survive.
That said, if the octopus loses its systemic heart, which pumps blood around the body, it is as good as dead. That is very doubtful. Losing two out of its three hearts means it has either lost both branchial hearts or one branchial heart and its main systemic heart.
Losing both branchial hearts means the octopus cannot get blood through the gills to be oxygenated. An octopus would die if it lost two hearts, it cannot live with just one heart. An octopus has two hearts that are located right next to the two gills that it uses for respiration. The hearts are called branchial because they contract to pump blood up through the gills of the octopus. There are about species of octopuses all over the world.
Some are so small you can hold them on your palm, like the Atlantic pygmy octopus. While others, like the giant Pacific octopus, can grow to about 16 feet. Because of this, the size of their hearts, are different for each type of octopus.
The systemic heart of the octopus is the main heart of the octopus. This deep-sea octopus was observed brooding her clutch of eggs for 53 months - that's nearly four and a half years.
It's the longest brooding period known for any animal. During the course of 18 dives to the depths of Monterey Canyon, California, the researchers never saw the female leave her eggs or eat anything, not even crabs or shrimp that wandered close by.
Instead, the researchers saw the female fading away - she lost weight, her skin became loose and pale, and her eyes grew cloudy. Her astounding self-sacrifice gave her offspring time to reach an advanced stage of development. On the researchers' final visit, the eggs had hatched and the female was gone. Although no other octopus is known to look after their eggs for such a long time, virtually all share the same fate: inevitable death.
Since male octopuses don't survive for long after sex, the sea is full of little orphan octopuses. Jon explains, 'Thousands of specialised cells under their skin, called chromatophores, help them to change colour in an instant. In addition, they have papilli - tiny areas of skin that they can expand or retract to rapidly change the texture of their skin to match their surroundings.
Inspired by the phenomenal camouflage ability of octopuses and cuttlefish , researchers have recently engineered a synthetic skin that mimics the function and design of the papillae, creating a stretchy material that can be programmed to transform into 3D shapes. Perhaps the most impressive of all self-concealers is the mimic octopus Thaumoctopus mimicus. Discovered in in Indonesia, this octopus doesn't copy surrounding rocks, reefs and seaweed like other octopuses, but instead disguises itself as other animals that predators tend to avoid.
By contorting its body, arranging its arms and modifying its behaviour, it can seemingly turn into a wide variety of venomous animals. Lionfish, banded sole and sea snakes are among those it impersonates.
Jon says 'Plenty of other creatures pretend to be other animals, but the mimic octopus is the only one that we know about that can impersonate so many different species.
It's a true shape-shifter. Mimic octopuses can flee from danger while disguised. This octopus is imitating a venomous banded sole. It even copies the swimming style of the flatfish. Scientists even suspect that the mimic octopus selects a creature to impersonate based on what's living in the area, choosing one that represents the greatest threat to its potential predator.
When a mimic octopus was attacked by territorial damselfishes, for example, it disguised itself as one of their predators, a banded sea snake. In , researchers reported another cunning solution for moving away from danger without breaking the camouflage illusion: walking away on two legs well, arms.
In the first example of bipedal locomotion under the sea, two tropical octopuses were found to lift up six of their arms and walk backwards on the other two.
This allowed the algae octopus Abdopus aculeatus to keep its other arms extended and maintain its appearance of algae even while moving. Meanwhile, the veined octopus Amphioctopus marginatus walked with six of its arms curled under its body, possibly to appear like a coconut rolling along the seafloor.
Both were able to move faster than their usual many-armed crawl. Take a look at the unusual locomotion in this SciFri video featuring researcher Dr Christine Huffard:. But in , scientists made a surprising discovery in Jervis Bay, Australia: the supposedly solitary gloomy octopus Octopus tetricus actually builds underwater cities.
Congregations of dens are formed from rock outcrops and discarded piles of shells from the clams and scallops the octopuses had feasted on. Population sizes certainly aren't up to London standards, with only around 15 occupants living in Octopolis, as it was dubbed, and Octlantis - a second, nearby octopus commune studied in But they are far higher than scientists anticipated based on the loner reputation of O.
City living has its advantages and drawbacks, as we all know. Frequent aggression, chases and even den evictions were observed among the octopuses living at Octlantis.
The researchers say they're not sure what the benefits of living in a densely populated settlement are for these octopuses, but it may just be a case of necessity, with limited den spaces available in the otherwise flat and featureless area. Well, the blue blood is because the protein, haemocyanin, which carries oxygen around the octopus's body, contains copper rather than iron like we have in our own haemoglobin.
The copper-based protein is more efficient at transporting oxygen molecules in cold and low-oxygen conditions, so is ideal for life in the ocean.
If the blood called haemolymph in invertebrates becomes deoxygenated - when the animal dies, for example - it loses its blue colour and turns clear instead. An octopus's three hearts have slightly different roles. One heart circulates blood around the body, while the other two pump it past the gills, to pick up oxygen.
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