A Salute to the Octopus

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Octopus. Read the word and you’re drawn amongst eight writhing arms into an alien world.  A world of surprising intelligence and the ability to navigate a maze2 or open a jar without hands or a backbone5. The octopus is more than meets the eye, and the more one studies it the more surprises surface.

The cuttlefish, a cephalopod like the octopus.

The squid, another cephalopod.

Octopuses (and this is the correct way to pluralize octopus despite its awkwardness – though some accept octopi as well1) are members of the Cephalopod class along with cuttlefish and squid5, and are in the Octopoda order. Octopuses go back at least 296 million years to the Carboniferous period, which is the time from which their earliest fossil remains date. The animals already had eight arms before the existence of true dinosaurs2.

Anatomy and Physiology

An octopus has three hearts!

Interestingly, the octopus has three hearts! The first heart provides circulation to  the organs, and the other two move blood past the gills. When an octopus swims as opposed to its typical crawl, the heart that provides circulation to its organs doesn’t beat – tiring the octopus out.  This is why an octopus only swims when it absolutely must2.

Hemocyanin renders octopus blood blue and is based on copper rather than iron as is hemoglobin.

The blood that that an octopus’ three hearts circulate is fundamentally different from ours in that it is composed of hemocyanin rather than hemoglobin. Whereas hemoglobin is based on iron, octopus’ hemocyanin (which gives the blood a blue color) is based on copper. This is helpful to the octopus as copper transports oxygen more efficiently in an octopus’ cold, underwater surroundings. Too acidic an environment can impair octopus blood’s ability to carry oxygen, which could become a problem as oceans acidify due to climate change2.

The arms of an octopus are also vastly different from human arms. Octopus arms are heavy in neurons and can act as if they have minds of their own. The arms can focus on a completely different task from that which the rest of the animal is performing. An octopus’ arms can remove prey from its shell, for instance, while the rest of the animal looks for further food. Even if they are entirely cut off from the creature, octopus arms can still respond to stimuli of their own accord2.

It is well known that octopuses, when threatened, excrete ink. The purpose of this ink, however, can be more than providing the octopus a way to hide from a predator. Octopus ink also contains a chemical called tyrosinase, which tampers with a predator’s senses of taste and smell. The chemical blinds the predator2 and can paralyze parts of it6. So damaging is an octopus’ ink that the octopus itself – once it has expelled the ink – must get away or die2.

Behavior

Researchers have found the octopus, which has a very large brain for a cephalopod, to be quite intelligent. Octopuses have been shown to be capable of problem – solving as well as recall of problems’ solutions. It has even been demonstrated that octopuses have their own individual personalities2!

The Common Octopus, considered to be the most intelligent invertebrate.

O. Vulgaris, the Common Octopus, is considered to be the world’s brightest invertebrate. The Veined Octopus has been known to utilize coconut halves as shelters, in a use of tools by a cephalopod6 . Such behavior is typical of octopuses. It is actually difficult to work with these animals in a lab setting due to their creatively mischievous antics. Octopuses can and do open jars, clear plugged drains, disconnect wires5 and  dismantle things just for the sake of it2. The creatures can even crawl along dry surfaces for a time if they find themselves out of water5.

A lab where an octopus escapes from its container could end up looking like this!

Despite their brilliance, however, octopuses live short lives – which often end  with mating and reproduction2 between one and two years of age8. Fertilization of octopus eggs by sperm is considered to be external. During mating, a number of male octopuses transmit their sperm to the female by either handing it to one of her right arms or putting their spermatophores (units of encased sperm7) into a funnel of the female that she typically uses for breathing2. To do this, a male octopus uses his hectocotylus – an arm meant for the purpose8.

After giving his sperm to a female, a male octopus goes away and soon dies. The female, meanwhile, develops as many as 400,000 eggs which she eventually lays and protects religiously. While the female octopus is guarding her eggs, she does not eat. When the young hatch, the body of the female in essence commits suicide on a cellular level. This suicide begins to occur in the optic glands and then  radiates outward until the entire animal is dead2.

Octopus eggs.

 

The Octopus as Food

A three ounce serving of octopus delivers the same amount of protein as a three ounce serving of chicken!

The surprises keep unfolding when you learn about the octopus as food – the practice of eating octopus being tradition in some East Asian and Mediterranean countries5.  Octopus (also known as sea cat in the West Indies) is actually quite nutritious in a number of ways – containing 12 minerals and vitamins. A three ounce serving of octopus is equal in protein content to a serving of chicken of the same weight, demonstrating octopus to be an excellent source of lean protein. Octopus is also low in fat overall3.

Three ounces of octopus provides 510% daily value of important Vitamin B12!

To keep your heart healthy, it is recommended that you get 1 gram of omega – 3 fatty acids per day. One serving of octopus provides over 25% of this 1 gram. Octopus is also high in the trace mineral copper – which is a component of several enzymes and also aids in the production of blood’s hemoglobin. Three ounces of octopus has 510% daily value of Vitamin B12, which helps the body to utilize fatty acids and is needed to create red blood cells. A serving of octopus also provides more than ones’ daily value of selenium. Selenium bolsters the immune system, is an antioxidant when partnered with Vitamin E, and is instrumental in cell growth. This serving of octopus also provides a little under fifty percent of the iron that a person should take in daily – iron being important in the development of the brain and the health of the immune system3.

Korea is currently the largest consumer of octopus.

Octopus for human consumption is largely harvested off West and North Africa for use in Greece, Spain, East Asia, and other places. Currently the greatest amount of octopus is consumed in Korea, and the food has also gained popularity in the U.S.2. An increase in demand for octopus in many countries has led to a decline in its catches in many locations over the past few decades3.  During the 1980’s this change led the octopus fishery to drift to Mauritania and Senegal2. If octopus continues to gain popularity as food, the animal could end up being farmed in the future5.

That octopus is becoming more popular does not mean that it is easy t0 prepare. Much effort is needed for the tenderizing that needs to be done to make octopus flesh palatable food. Octopus flesh can be tenderized by force, massage, braising, and / or blanching. Salting is needed as well.  Thankfully for us consumers most wholesale octopus, however, has already been tenderized. This has typically been done by tumbling the flesh in ice and sea salt5.

San nak ji.

One can also avoid having to tenderize octopus flesh, albeit in a drastic way, by eating the octopus alive.  A Korean dish called san nak ji serves octopus in this manner, in pieces that move independently of each other5. This way of serving octopus is clearly controversial5.

However it is consumed, the nutritious octopus is considered a delicacy by many5. Following are some recipes that involve octopus should you like to surprise your loved ones by trying it for dinner some night. Keep in mind that frozen octopus of great quality, octopus salad, and  the usual fresh, healthy seafood offerings of September are available today at Atlantic Seafood!

“Octopus Recipes”

“More Octopus Recipes”

Octopus salad.

 

Works Cited

1. “Octopi vs. Octopuses”.
Grammarist, grammarist.com/usage/octopi-octopuses/.
Retrieved 25 Aug. 2018.

2. Nuwer, Rachel. “Ten Curious Facts About Octopuses”.
Smithsonian.com, 31 Oct. 2013, www.smithsonianmag.com/science-nature/ten-curious-facts-about-octopuses-7625828/.

3. DeLacey, Emily & James, Roan. “The Nutrition of Octopus”.
fitday.com, www.fitday.com/fitness-articles/nutrition/healthy-eating/the-nutrition-of-octopus.html.
Retrieved 23 Aug. 2018.

4. Barry, P.. “Taxonomy”.
University of Alaska Southeast, 2008, www.uas.alaska.edu/arts_sciences/naturalsciences/biology/Tamone/catalog/mollusca/enteroctopus_dofleini/Taxonomy.html.
Retrieved 26 Aug. 2018.

5. Killingsworth, Silvia. “Why Not Eat Octopus?”.
THE NEW YORKER, 3 Oct. 2014, www.newyorker.com/tech/elements/eating-octopus.

6. The Editors of Encyclopedia Britannica. “Octopus”.
Encyclopedia Britannica, www.britannica.com/animal/octopus-mollusk.
Retrieved 29 Aug. 2018.

7. “spermatophore”.
Merriam – Webster, www.merriam-webster.com/dictionary/spermatophore.
Retrieved 30 Aug. 2018.

8. Death by Divas. “Life Cycle of an Octopus”.
EVERTYTHING OCTOPUS, 1 Mar. 2009, http://everythingoctopus.blogspot.com/2009/03/life-cycle-of-octopus.html.

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