Gills & Respiration

How do sharks breathe?

Like other fish, sharks have gills to aid in respiration. Sharks have between 5 and 7 gill slits located on the side of ‘the head. Water has to be constantly passed over the gills slits to enable gas exchange to occur. Water flows into the shark’s mouth as the shark swims forward, passes into the pharynx, over the gills and finally leaves through the gills slits. Oxygen in the water is absorbed into tiny blood vessels near the gills, which then carry oxygen around the body. 

shark gill diagram low.jpg

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Lemon shark breathing 

Obligate Ram Ventilation 

With this method of breathing sharks swim forward with their mouth open, allowing water  to move in and over the gills. These sharks have lost the ability buccal pump as they no longer have the correct anatomy to do so. 

Species: White sharks, mako sharks and whale sharks. 

whale shark feeding & breathing 

Buccal Pumping 

This method of breathing is named for the buccal ( mouth)

muscles that draw water into the mouth and over this gills. This allows the shark to breathe while at rest. 

Species: Nurse sharks, whitetip reef shark, Port Jackson shark

Both

Some sharks have the ability to switch between ram ventilations and buccal pumping. 

Species: Lemon sharks, tiger sharks 

spiracle sharks and rays.jpg

Spiracles 

 

Rays and some species of shark have paired openings behind the eyes. The spiracles take water into the buccal space before it is then moved to the gills for respiration. It allows bottom dwelling species to breath, even if the animal is mostly buried in the sediment ( sand). 

Species: Wobbegongs, shark rays, angel sharks.