Building on the success of the documentary My Octopus Teacher, a team of researchers from Queensland studied the brains of octopuses using MRI technology to find out why they are so intelligent.
- Queensland researchers studied the brains of four species of octopus
- Reef octopuses had significantly larger brains
- Some have teamed up with reef fish to hunt for food
The team at the Brain Institute at the University of Queensland took four species of octopus, two of which live on the Great Barrier Reef, and studied their brain structure using ultra-detailed MRI imaging.
The results, published in the scientific journal Current Biology, showed for the first time that reef octopuses had significantly larger brains than octopuses that lived in deep water – a finding that will provide information on how the structure of the brain is linked to behavior and cognition.
Postdoctoral researcher Wen-Sung Chung said one of the study’s goals was to find out why invertebrates had such a short lifespan – around a year.
“Why are they putting so much power, so much energy into developing their brains?
Dr Chung said octopuses are estimated to have 500 million neurons.
âThey are quite amazing; they have eight arms and no joints and they have to control their movements through the very complex seascape.
“They are also totally color blind, they can only see blue or green, and how they manage to see the reef and then blend well with the background is a big unknown,” said Dr Chung.
Unusual cross-species friendships
Dr Chung said the researchers also studied the relationship that developed between octopus and reef fish during the hunt.
He said the sightings were made during visits to Lizard Island, off the coast of far north Queensland.
He said the animals were able to communicate with each other to hunt together.
âThe ability to receive and respond to gestures between different species in collaborative hunting demonstrates that octopus species have complex cognitive abilities,â said Dr Chung.
He said the find was significant, given the species’ usual behavior.
âMost of the time, they live alone and very rarely interact with others.
“For nocturnes in particular, they live alone until mating season and find a mate, otherwise they will go out alone to catch crab or clams.”