Sharks do not have lungs. They breathe through gills.
Sharks and rays have rows of gill slits on each side of their bodies, just behind their head.
Most sharks have pairs of gills slits.
The gill slits open to enable water to exit their body, and close to prevent water entering their body.
When sharks are swimming, water passes through the mouth and over the gills. This is called ram ventilation.
When sharks are resting, water is pumped over the gills for a constant supply of oxygenated water.
Photographer: Martina Nicolls
Martina Nicolls: SIMILAR BUT DIFFERENT IN THE ANIMAL KINGDOM