• An octopus has three hearts. One pumps blood through its organs; the two others pump blood through its gills, according to the World Animal Foundation. Octopus blood is blue because it has a copper-based protein called hemocyanin.
• Octopuses have short life spans. Some species only live for around six months. Other species, like the North Pacific giant octopus can live as long as five years. Typically, the larger the octopus, the longer it lives.
• Females usually lay 200,000 to 400,000 eggs, though it varies depending on species. She obsessively guards the eggs until they hatch. She even stops eating.

To find the source follow the link below:

https://worldanimalfoundation.org/advocate/wild-animals/params/post/1292109/octopuses