With 289 species of octopus living in the world’s oceans one would think they were relatively easy to find when diving or snorkeling. However, we can spend hundreds or even thousands of hours in the water and never see one although they have probably seen us.
Octopus, meaning ‘eight footed’, are one of the most fascinating and intelligent species in the sea.
They are classified as Cephalopods (translated as a head with feet), and are related to Cuttlefish, Squid, and the Nautilus. In fact, marine scientists believe that the octopus evolved from the Nautilus some 490 million years ago, well before there were fish in the seas and animals on land.
How Big do they get?
The size of octopus varies widely from the tiny California octopus that is 1″ long when mature to the Giant Pacific octopus having an arm span of 25 feet and weighing over 400 pounds.
How long do they live and what are their lives like?
Their lives are short with the smallest species living an average of 6 months while larger species live approximately 3 years. Octopus are generally shy, reclusive, often nocturnal, and pose virtually no threat to man as long as they are not harassed. That said if an octopus is threatened it would use its powerful bird-like beak to inflict a painful, damaging bite. The beautiful little Blue-Ringed Octopus of Australia is the only species that carries highly toxic venom, which can kill in minutes.
Octopus are considered to be one of the most intelligent marine animals.
Studies in labs and in the wild have proven time and again that they have advanced thought processes that enable them to solve problems, build shelters, trap prey, and escape confinement. During early lab studies scientists were baffled when fish populations in tanks were dwindling despite the fact there were no bodies in the morning and no way for the fish to escape. What they discovered was that octopus in tanks nearby were climbing out of their tanks at night and into the fish tanks to dine. When observers were left in the labs at night to watch how the octopus escaped their fully enclosed tanks nothing happened and the octopus stayed put. After several nights the observers gave up their vigil and the fish tank raids began again.
After many years of searching for octopus while diving my efforts were rewarded recently as I swam along the edge of a reef and noticed a rock that seemed somewhat out of the ordinary.
As I turned back toward the rock to examine it the rock suddenly swam towards me. I spent 90 minutes swimming along the reef with a Common Octopus (octopus vulgaris) as it changed colors and textures to match its surroundings. One minute it was smooth skinned, the color of the sand on which it rested. The next minute it spewed powerful jets of water from its siphons and shot along the reef to land next to sponges whereupon its skin became a mottled, dimpled brown. A few minutes later the octopus propelled itself to a patch of sand from which a very dark strip of rock protruded. To my amazement the octopus turned itself white with a wide black stripe running down its midline. Sadly and with dwindling air supply I left the octopus on a coral head where he had
turned himself a yellowish red and his skin had become peaked with hundreds of tiny points. As I swam away that morning a large group of divers passed over the octopus, only a foot distant and not one noticed he was sitting on that coral head in all his magnificence.