Octopus

Fascinating facts about the Octopus

• Even the largest octopus species can squeeze through a gap only a little larger than 2.5 cm, roughly the width of a thumbnail, because their bodies are composed almost entirely of soft tissue without any skeletal support. This extreme flexibility lets them flatten and contort their arms to pass through openings that would seem impossibly small for their size.
• Octopuses move blood through a closed circulatory system powered by three hearts: one systemic heart that distributes blood to the body and two branchial hearts that pump it through the gills. Their blood contains the copper-rich protein haemocyanin, which gives it a bluish colour and makes it more viscous, requiring high pressure that can exceed 75 mmHg (10 kPa).
• The octopus nervous system contains over 500 million neurons, a count comparable to that of a dog, with roughly two-thirds of these neurons located in the nerve cords of its eight arms. This distribution gives each arm a high degree of autonomy, allowing it to process sensory information and execute movements even when detached from the central brain.
• Every octopus species produces venom, a trait shared across the order. However, only members of the blue-ringed group have venom that is recognised as lethal to people, meaning a bite from those can cause death. Bites from other octopuses may be painful but are not known to be fatal, so they pose little human danger. This distinction makes the blue-ringed octopus the sole deadly representative among its venomous relatives.
• Giant Pacific octopuses typically weigh between 10 and 50 kg and can reach an arm span of up to 4.8 m, placing them among the largest cephalopods. The biggest scientifically documented individual measured a live mass of 71 kg while still fitting within that maximum span. Unverified accounts speak of a monster weighing 270 kg with arms stretching 9.8 m, far beyond the normal range.

Sources

Every fact above was checked against these pages, and kept only where one of them states it.

• Wikipedia

At a glance

About the Octopus

As the octopus glides effortlessly through the coral labyrinth, its undulating form seems to embody the very essence of fluidity, as if the ocean itself had taken on a life of its own. With a mesmerizing dance of color and texture, it navigates the underwater world, its eight dexterous arms rippling like a dark, liquid cloak as it probes the shadows for hidden prey. In this masterful display of camouflage and cunning, the octopus reveals itself to be a shape-shifting virtuoso, a true marvel of evolution.

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