Octopuses are one of the most fascinating and one of the most intelligent creatures that we work with at the Andaman Sea lab. Although they are invertebrates (no internal skeleton) and closely related to snails and slugs, they are probably the most intelligent of all animals without a backbone.
Many experiments have been done that show that octopuses have good short and long term memory. Their intelligence is high in both finding their way through complicated mazes and in problem solving.
The deep sea Dumbo octopus is really very smart
Scientists here at the lab believe that the only reason octopuses haven’t taken more dominant positions in the ocean is due to their short life span of 1-5 years that limits their experiences and how much they can learn.
Octopus unscrewing jar lid to get food
On one occasion we kept losing fish from an aquarium over night; each morning another fish was gone. Eventually a trail of water led us back to the octopus tank. We discovered that once the lights were out our eight armed burglar was climbing out of his aquarium, across the bench, and into the fish tank for dinner. When it finished off the fish it returned to its tank and favorite cave. There are even stories of octopuses climbing on to fishing boats to get at the boxes of crabs.
On another occasion we have seen an octopus ‘playing’ in its aquarium with a floating thermometer. The octopus would drag the thermometer to the bottom then let it go in the current watching it rise to the surface. When it floated past again the octopus climbed to the surface and repeated the game. He would do this for an hour or two and then start again the next day playing with his toy.
This octopus is carrying a shell to hide under if it needs protection
Octopuses have been taught to distinguish shapes in order to get a food reward. One example has been described of an octopus mimicking shapes shown to it on cards by making “X” and “O” with its arms.
So, does an octopus have a big brain?
The answer is yes, for an invertebrate, but two-thirds of the octopus’s nerve cells are in its arms. The arms are incredibly sensitive to touch and the skin can be moved into odd shapes that look like seaweed or gravel when the octopus wants to hide.
Even more complex is the ability to change colors and patterns within one or two seconds. Special cells in the skin called chromatophores contain yellow, orange, red, brown, or black color. Most octopuses have three of these colors but some have four. Other color cells are reflective (iridophores) and white (leucophores). The Blue-ringed octopuses use the iridophores to flash warning circles to advertise its deadly bite.
A newly hatched octopus ready to start solving problems