How many chambers does a shark's heart have?

The heart of a shark has two chambers and is a tube-shape like the letter "S." The route of blood through the body goes from the shark's heart to its gills and then to its body tissue.

Sharks have low blood pressure due to the walls of the pericardium, which are the sacs that enclose the shark's heart, being rigid to create suction to maintain the flow of blood throughout the shark's body. Some sharks must swim continuously in order to keep blood circulating.

Notably, the shark has a modified circulatory system that helps it to retain heat in its muscles.