Octopuses have three hearts that work simultaneously to keep the octopus alive. How Many Tentacles Does an Octopus Have?.How Many Stomachs Does an Octopus Have?.What Other Creatures & Animals Has Three Hearts?.Do Octopus Have Blood and What Color is their Blood?.Can Some Octopuses Have More Than Three Hearts?.Purpose, Description & Size of each Heart in the Octopus.Does an octopus need all three hearts to survive?.“The brain of octopuses is so different – it’s still a black box to us really,” concluded Dr Gutnick. While scientists have some grasp of how a high level of intelligence has evolved among certain species, such as chimps or dolphins, most of their theories fall flat when applied to the curious world of cephalopods. More fundamentally, it's unclear why octopuses and other cephalopods are so intelligent. For starters, it’s unclear how much information is communicated between all these different neutral structures and why their nervous system is structured in this way. Nevertheless, there are still many mysteries that surround the octopus brain. “We conclude that although octopus arms have a great capacity to act independently, they are also subject to central control, allowing well-organized, purposeful behavior of the organism as a whole,” the study reads. This process of learning, the researchers say, shows that the tentacles require the central brain and they are not autonomously acting like an independent mind of their own. Most crucially, they could successfully navigate the maze using arms that hadn’t been used before. The study showed that five out of the six octopuses eventually learned the correct direction to push or unroll their arm through the maze in order to get the food. If they got the correct tube then they would find the food, but if they entered the wrong tube, the food was blocked by a net and the scientists removed the maze. They appeared to explore the maze using fast movements, by pushing or unraveling their tentacle straight through the tube into the end box.
The maze consisted of a Y-shaped pipe, in which the octopus can either put its tentacle down the right or left path to find a food reward. To reveal this, the researchers looked at common Mediterranean octopuses to see if single arms were able to provide the brain with two different types of sensory information through a number of maze experiments. Rather than talking about an octopus with nine brains, we're actually talking about an octopus with one brain and eight very clever arms,” lead author Dr Tamar Gutnick, an octopus researcher formerly at the Okinawa Institute of Science and Technology Graduate University in Japan, said in a statement. “This study makes it clear that octopus's arms don't behave totally independently from the centralized brain – there's information flow between the peripheral and central nervous system. However, recent research suggests this isn't strictly true (though rest assured, the new insights show that their nervous system is still deeply unusual). The new study, reported in the journal Current Biology, has looked at the central nervous system of octopuses and revealed that their arms don't actually act independently from the centralized brain, but are, in fact, more connected than previously thought. As such, they are sometimes said to have nine brains – a donut-shaped one in their head and eight other “mini-brains” located in each tentacle – leading some scientists to wonder whether the arms effectively have a “mind of their own” that can act independently from the central brain. They possess around 500 million neurons, over two-thirds of which are located within their arms and body. Octopuses have three hearts, blue blood, and a freakishly strange nervous system like no other creature.