Do the words Octopolis & Octlantis mean anything to you?
Let me begin by telling you that they are in fact 2 cities you can find in Jervis Bay, Australia. Well, you can if you are a scuba diver of course! They are indeed underwater cities …built by Octopus!
In order to study the behaviour of these marvellous builders, scientists have even installed cameras within the cities located at around 10 to 15 metres deep, and have counted up to 15 octopus!
Brandished “Environmental Engineers” for their wall building, den building and city building skills, the researchers were also able to witness evidence of a real community life including communication, gatherings, conflicts and even some “den theft” & evictions! Behaviour which bizarrely reflects that of humans!
These creatures, which we once believed to be solitary may not be at all, or so scientists understand, even going as far as the hypothesis they may have their own culture! It’s interesting to remember here that octopus are renowned for their extraordinary brain, made up of 500 million neurones, and their incredible cognitive capacities.
There are 300 different species of octopus to be found on our planet and the scientists, who have probably only touched the surface when it comes to really knowing these marine creatures, believe there are some extraordinary discoveries yet to be unfolded!
For the interest of this marine file we will be looking at the facts concerning the common octopus …
Geographical distribution: North Sea, English Channel, Atlantic Ocean and of course in the Antilles
Depth: Mainly found on rocky bottoms from a few metres to about 150 metres
Family: Cephalopoda part of the phylum Mollusca
Size: from 60 cm to 1.20 m / 1.30 m for larger specimens
Description: Bulbous head, branching off into eight arms distributed in a star formation with suction cups. It has two large eyes characterised by a horizontal pupil; the mouth is like a parrot's beak.
Diet: it is a carnivorous animal particularly enjoying crustaceans and molluscs; he uses shells to build his den; so he recycles all his waste!
Reproduction: male octopuses reproduce using one of their tentacles called the third arm and inserting it into a cavity in the female; the female will then lay between 100,000 and 500,000 eggs which she will ventilate until they hatch
Lifespan: from a few months to 4 or 5 years depending on the species
Predators: congers, morays, other octopuses; and of course the worst … humans … yes another species at the peril of human consumption!
Another interesting observation to be made with these wonderful creatures is their amazing ability to blend into the background. A skill needed if you are to avoid becoming the next meal of your predator! Their camouflage mechanism found in their “skin”, means they are able to change their colour continuously to suit the background of where they move to. Watch the video below to see this “master of disguise” at work for yourselves!
Different observations of octopus in various "colour settings", watch how they adapt!