The octopus is of the order Octopoda, and it has its mouth at the centre point of the arms - which are sometimes mistakenly called "tentacles". Typically arms have suckers along most of their length, as opposed to tentacles, which have suckers only near their ends. Or the bars in Wanchai, which are full of suckers when the navy is in town.
Some Octopuses live in the abyssal depths, but they can also be found in Hong Kong in the intertidal zone, like this one which i found near Tai Mei Tuk/Plover Cove when looking for crabs with my son.
The octopus is bilaterally symmetric with two eyes and a beak, which is really spooky if you have ever seen one, and the stuff of movie legends as giant denizens of the deep attack. All octopuses are venomous, but only the blue-ringed octopuses are known to be deadly to humans.
This amazing photograph is of a North Pacific Giant Octopus is by the photographer Mark Laita (used with permission). He blends the best of both commercial "wow" images, with art, with natural history, and his book "Sea" contains some of the best images of Sea creatures i have ever seen. Buy it on Amazon.
Octopuses are fascinating creatures, and I encourage you to read the book reviewed by me below. They use their siphon for both respiration, and for locomotion by expelling a jet of water, and can move quickly through the water. They are masters of camouflage, can change colour, can expel ink, and the soft body can rapidly alter its shape, enabling octopuses to squeeze through small gaps. Octopuses have a complex nervous system, excellent sight, and are among the most intelligent and behaviourally diverse of all invertebrates, or indeed perhaps animals in general (read the book!).
The Soul of an Octopus is an astonishingly beautiful read. After our introduction to the author, and her local aquarium, the book takes a deep dive questioning scientific, universal and religious truths and the chapters flow forward at once scientifically illuminating, whilst also remaining deeply poetic. “While stroking an octopus, it is easy to fall into reverie. To share such a moment of deep tranquility with another being, especially one as different from us as the octopus, is a humbling privilege. It’s a shared sweetness, a gentle miracle, an uplink to universal consciousness”.She writes:”The ocean, for me, is what LSD was to Timothy Leary. He claimed the hallucinogen is to reality what a microscope is to biology, affording a perception of reality that was not before accessible. Shamans and seekers eat mushrooms, drink potions, lick toads, inhale smoke, and snort snuff to transport their minds to realms they cannot normally experience….In my scuba-induced altered state, I’m not in the grip of a drug: I am lucid in my immersion, voluntarily becoming part of what feels like the ocean’s own dream”.
The book’s greatest reward isn’t the fascinating science — although that is riveting and ablaze with rigor — but Montgomery’s mesmerising prose, pouring from the soul of a literary naturalist who paints the marvels of the ocean’s depths, like Attenborough narrates Life on Earth with a unique voice of enthusiasm, knowledge and pleasure.