India, Nov. 7 -- Imagine an animal with three hearts, blue blood, and eight arms that can move independently. It may sound like something from a science-fiction movie, but this unusual creature exists in oceans around the world. The animal is the octopus, one of the most fascinating marine creatures. Its unusual body structure and circulatory system help it survive underwater.

Which Animal Has Three Hearts?

The octopus is famous for having three hearts instead of one. It belongs to a group of marine animals called cephalopods, which also includes squid and cuttlefish.

Unlike humans, octopuses have a specialised circulatory system in which each heart performs a different function. This arrangement helps transport oxygen throughout their...