If an octopus has 8 arms, how many hearts does it have?

Question: If an octopus has 8 arms, how many hearts does it have?
- Keywords:
  animal,
  octopus
Asked by pingupace to Janet on 14 Mar 2013.
- Janet Daly answered on 14 Mar 2013:
  
  It has three hearts…but not because of its 8 legs…one pumps its blood around its body, the other two pump blood to each of its gills, which are equivalent to our lungs and where it gets its oxygen from.

Question: If an octopus has 8 arms, how many hearts does it have?