After Part 1, some more about our octopus friends. Strange and wonderful alien creatures… Read on to know how amazing and bizarre they really are…
They have three hearts
Octopuses not only have a big heart they also have two smaller ones to boot. The small ones are close to the gills and pump oxygen into the blood which they then transfer to the larger heart. The big heart then pumps the O2 rich blood to the rest to the body.
They have brains in their arms (they're not called tentacles, in fact)
The Octopuses brain is amazing not only because of its great intelligence, it also has the ability to delegate to the other ‘mini brains’ located at the base of each arm. These surrogate brains control the arm movement and other receptors independently. Over 2000 individually moving suction cups are equipped with chemical sensors that send back touch, taste and smell information to the 'mini brains'. The main brain can concentrate on its objective whilst the mini brains send back information by testing the water and ocean floor and probing crevices for instance. A detached octopus arm can still react to pain, it literally has a brain of its own.
Their arms grow back
Octopuses, like lizards and starfish, have the ability to grow limbs back. If an arm gets lost to a predator in a battle, a brand new one grows back, perfect down to the last suction cup, quite a luxury when you have seven other arms!
They have blue blood
Because they are the kings or queens of the sea you might think, but no, that’s not the reason Octopuses have blue blood. Their blood is copper based not iron based like ours. Copper is more efficient at transporting oxygen - handy in low oxygen environments - and happens to make for blue blood.
They can kill 26 humans in one bite
One of the cutest octopuses and most sought after by scuba divers, the blue ring octopus is actually a deadly killer able to fell 26 humans in less than a minute with the venom from just one bite. Of course, it never gets the opportunity to bite 26 humans at once…But beware, this very small (20 cm) and pretty (cute blue rings) cephalopoda’s bite is completely painless and has no known anti-venom.
They see with their skin
Octopuses have colour changing cells (chromatophores) in their skins. Despite being colour blind, they are able to copy patterns with their skin to blend in with their surroundings, becoming almost invisible. Some recent studies even suggest that they can even ‘see’ with their skin. The skin detects the light and responds to it by changing colour and pattern. They can not only alter the colour but also the texture and shape of their bodies to look identical to their surroundings and practically disappear from sight.
They are unbelievable contortionists
Part of the reason octopus are such incredible escape artists, apart from their hiding ability, is their ability to fit through tiny opening and into tiny enclosures thanks to their complete lack of bones. The only hard part of their body is their cartilaginous beak. A normal sized common reef octopus (arms up to one meter long) was filmed escaping through a hole less than 2.5 centimetres in diameter, another was seen slipping into a beer bottle to hide!
A tale for another day is their incredible parenting sacrifice, their ink squirting and their taste for play, using toys sometimes… Part 3 may yet be in the pipeline….