The Giant Pacific Octopus


Enteroctopus dofleini


Habitat

The Giant Pacific octopus is a marine creature. It inhabits the Northern Pacific waters. As you can see in the map the region stretches from southern California  to North Korea. They prefer water temperatures of 60 degrees Fahrenheit and cooler. The water depth in which they live ranges from the shallow, coastal waters to about 330 feet deep.  They tend to live on the ocean floor. They live in little nooks that are called dens.  Dens are a very important place of shelter for these octopuses. They enjoy spending their time in areas under rock cover where they can easily camouflage themselves. They often create, or choose, a den that has many entrances. The Pacific octopus rarely lives in a single den for longer than one month, unless it’s a female with her eggs. Dens left uninhabited are frequently moved into by other giant octopuses, who then live there for another short period of time.

Fertilisation

There are two ways giant pacific octopuses can fertilise. They fertilise externally and use cross- fertilisation. The male octopus has a modified arm called the hectocotylus,( showed in the visual below) which is about a meter long and holds rows of sperm. The male octopus will either approach a friendly female and insert the arm into her oviduct OR take off the arm and give it to her to store in her mantle for later. The female stores the sperm within her body, until she is ready to lay the eggs. When eggs travel out of the female's body, they travel past the contained sperm and become fertilized. About 20,000 to 100,000 eggs, each the size of a grain of rice, will be laid. She places these eggs along the wall of a chosen den. It will take her a couple of days to lay all of them. The female meticulously cares for her eggs until they hatch. The eggs might incubate anywhere from two to 10 months, depending on the water temperature.

Development

The embryo( shown in visual below) developmet is external meaning the octopus is a oviparous animal which means they get little or no development within the mother.As you can see from the visual below the octopi are developing externally and no development is happening within the mother. The gestation period is about 150-230 days, about 6 or 7 months, for the eggs to hatch.The female will rarely leave the eggs during the entire incubation period , the mother won't even sleep or eat. After they hatch, she will blow them out of the den and into the open ocean, the offspring quickly swim to the ocean's surface.The embryo development in humans is internal and we are viviparous, which means octopuses are completely opposite to humans. However humans care for there child before it is born in the same kind of manner that female octopuses care for there eggs before they hatch.


Parental Care

For the 6-7 months of gestation the female octopus takes care of  her eggs meticulously. She takes care of them so well that she doesn't stop to eat or sleep. The female octopus blows currents over her eggs so that no fungi or bacteria gets onto them.However, when the time comes for them to hatch she will blow them away into the open ocean, which means they will be on  their own from then on wards. After that she will most likely die from fatigue and starvation. The mortality rate is unknown but octopuses generally live for 3-5 years. Octopuses are r-selection as many offspring are produced, each individual reproduces only once, they have a short life expectancy,early maturity, most individuals die within a short time but a few live much longer and  they come in a small size of organism. There is very little parental care because the only thing an octopus needs to provide for its self is food, a den to live in and they need to reproduce. Therefore, i think they get the right amount of parental care.

Interesting facts

-The common octopus has a wide array of techniques it uses to avoid or thwart attackers. Its first—and most amazing—line of defense is its ability to hide in plain sight. Using a network of pigment cells and specialized muscles in its skin, the common octopus can almost instantaneously match the colors, patterns, and even textures of its surroundings. Predators such as sharks, eels, and dolphins swim by without even noticing it.

-Octopuses have three hearts. Two pump blood through each of the two gills, while the third pumps blood through the body.

-When discovered, an octopus will release a cloud of black ink to obscure its attacker's view, giving it time to swim away. The ink even contains a substance that dulls a predator's sense of smell, making the fleeing octopus harder to track.

-If all else fails, an octopus can lose an arm to escape a predator's grasp and re-grow it later with no permanent damage.

Bibliography

By Rachel de Sousa

Comment Stream