The octopus is one of the most enthralling creatures of the sea and definitely among our favorite creatures to spot whilst scuba diving or snorkeling. Octopuses fascinate, amaze and surprise time and again, no matter how often we encounter them. Yet it is a creature that is so little understood or appreciated … often more feared than loved. But why? Is it its alienlike appearance? Or the cloud of black ink that it only uses for defense? Is it its ability to morph endlessly into different shapes?
Over the years it is through the efforts of scientists and underwater naturalists that we have come to know more and more of this beautiful creature. Yet its ‘fanbase’ remained relatively small and anonymous. Until now that is! "My Octopus Teacher" is an extraordinary documentary that premiered on Netflix in September. It tells the real-life story of how a man coping with exhaustion and burnout regains purpose by developing a relationship with an octopus. Every day for over a year, Craig Foster went free diving in the frigid waters near Cape Town (South Africa) to visit and observe an octopus. The wonderfully captured footage of the trust building over time between a man and a curious, creative octopus is truly moving and inspiring. Since its release this mind-blowing film has gone viral, rapidly growing its audience through word of mouth. In short, most definitely worth a watch!
Before you switch to Netflix grant us just a few more minutes of your time to get you started with eight great-to-knows.
For starters the Greek ‘angle’. The starring octopus in the film is of the species Octopus Vulgaris, the most commonly occurring and most studied octopus species in the oceans and seas. It is also the species that you are most likely to encounter along the shores of Greece. The name ‘octopus’ is derived from Ancient Greek ὀκτώπους, a compound form of ὀκτώ (oktō, "eight") and πούς (pous, "foot"). The numerous depictions of octopuses on ancient Greek amphorae led some thinkers into believing that Minoans worshipped the sea and the creatures therein. Minoan culture flourished from 2700 BC to 1500 BC. These ceramic pieces of art were made by trained craftsmen and were prized throughout the Levant. In classical Greece, the philosopher Aristotle (384-322 BC) commented on the color-changing abilities of the octopus, both for camouflage and for signaling, in his Historia animalium: "The octopus ... seeks its prey by so changing its color as to render it like the color of the stones adjacent to it; it does so also when alarmed." (Wikipedia)
An octopus has eight arms (not legs … and certainly not tentacles) each covered by approximately 280 suckers. Each individual sucker has the ability to taste, smell and feel. Just imagine how much information is being processed by the octopus! Over two-thirds of an octopus’s neurons are found in its arms, not its head. But is doesn’t stop there! The suckers can also fold, performing a ‘pinching’ maneuver allowing the octopus to grab and hold objects.
Octopuses are very smart, renowned for their problem-solving skills, exceptionally skilled escape artists and good with tools. These extraordinary abilities in combination with the multitude of stimuli reaching them through their suckers require an enormous ‘computing and processing’ capacity. It is therefore not entirely surprising that octopuses have nine brains; a small brain in each of their eight arms and a central brain controlling the nervous system. This allows the arms to work independently of each other and yet, together, toward the same goal. "Each arm is somewhat autonomously, sensing and interpreting its environment, manipulating objects and potential prey and basically acting of its own accord” (Oregon Coast Aquarium, 2020).
With lack of better wording … octopuses are blessed with super-skin. Octopuses can change the color and texture of their entire body in just three-tenths of a second. "Specialized organs in their skin called chromatophores expand and contract to produce an array of colors, patterns and textures, including bumps, ridges and even ‘horns', above their eyes (Oregon Coast Aquarium, 2020). But there is more! Octopuses have the ability to ‘see’ with their skin. A light-sensitive protein known as rhodopsin embedded within an octopus’s chromatophores enables the skin to perceive visual stimuli. Amazing isn’t it?
All the exceptional traits and behaviors described so far contribute to an extraordinary physiological dynamic demanding ‘fuel’. This ‘fuel’ is provided through an efficient circulatory system powered by three hearts. Two hearts pump blood to the gills to be oxygenated and a larger heart circulates blood to the rest of the body.
Life in the oceans and seas is harsh with marine life exposed to lower temperatures and low-oxygen conditions. Whilst human blood used iron-based haemoglobin to transport oxygen through our bodies octopuses rely on a copper-rich protein called hemocyanin to do the same job. Hemocyanin is more efficient in these cold, low-oxygen conditions, turning the octopus’s blood blue when exposed to air.
Both male and female octopuses sacrifice a lot for their offspring. Octopuses mate via external fertilization with the male octopus ‘presenting’ (inserting or sometimes even ‘handing over') a pocket of sperm to the female using a specialized arm called a hectocotylus. This arm often leaves with the female once they’ve mated and parted ways. Octopus mothers sacrifice their lives after laying their eggs. While durations vary with the different octopus species the females do live with their eggs for months without eating, ensuring that streams of oxygen- and nutrient-rich water waft over them. Octopus mothers usually die after the eggs hatch.
While it is not entirely impossible that you will see an octopus with less than eight legs it is very unlikely. Octopuses have amazing regenerative powers allowing them to completely regrow lost arms. Once an arm is lost or damaged, a cascade of chemical signals within the octopus trigger a regrowth process to make the limb whole again resulting in a good-as-new arm.