Why do octopuses have three hearts and nine brains? 

Mother Earth is home to millions of species and each has its own unique characteristics. However, a lot remains to be discovered yet in the animal kingdom. One such mystery that humans have recently managed to solve is, why octopus, the eight-armed marine animal has three hearts and nine brains. Here is what you need to know.  

Why do octopuses have three hearts? 
Octopus, the animal that continues to intrigue us, has three hearts in total. There are primarily two hearts that are made for the gills and are used to pump blood to them. Then there is the third heart, right at the centre and larger in comparison to the two other hearts, and its main purpose is to supply oxygen to the blood and in turn supply it to the rest of the body, so that all the organs can function properly.   

Why do octopuses have nine brains? 
The octopus is often considered the most intelligent creature, even more than humans, because it has nine brains. But how does this creature utilise its nine brains? Well, each of its eight tentacles has their own mini brains that allows them to act independently and control the arm movements making the creature attain distributed brain power. The final brain is of course the central brain (shaped like a doughnut) that helps an octopus regulate and perform other bodily functions. In fact, the central brain forms a ring around its oesophagus, which is why, when the creature swallow food, it passes through the brain.  

Why do octopuses have blue blood? 
While most animals have red blood, octopus is endowed with blood, that is blue in colour. This is because instead of the iron-based protein called haemoglobin that makes our blood red, octopus has copper-based protein called hemocyanin, that makes the blood turn blue. Unlike haemoglobin, hemocyanin does not mix well with oxygen easily. For this same reason, there are two hearts that pump blood through the gills, and the third heart helps pump blood and oxygen to the rest of the body. Furthermore, the blue blood also helps the octopus adapt to cold and low oxygen water ecosystem.