The Great White Shark (Carcharodon carcharias) is perhaps the most globally recognized apex predator in the ocean. This massive fish commands respect across marine ecosystems due to its impressive size, powerful swimming, and refined predatory adaptations. Like all fish, the Great White relies on an efficient respiratory system to extract oxygen from the surrounding water. Understanding how this powerful hunter breathes provides significant insight into its active, open-ocean lifestyle.
The Exact Number of Gill Slits
A Great White Shark possesses five distinct gill slits located on each side of its head, just ahead of the large pectoral fins. This means the animal has a total of ten external openings for respiration. This configuration is the most common found across the vast majority of shark species. The slits are visible externally as five separate, vertical openings, which lead directly into the internal gill arches.
The location of these slits is strategically placed to accommodate the shark’s forward motion. As the shark moves, water flows sequentially through the gills, allowing for continuous gas exchange. The five-gill structure is a standard biological trait for this pelagic, fast-swimming species.
The Unique Way Great Whites Breathe
The gills are complex organs designed for gas exchange, featuring thousands of fine gill filaments rich with tiny blood vessels called capillaries. As oxygenated water flows over these filaments, oxygen diffuses into the shark’s bloodstream, while carbon dioxide is released back into the water. This process is the core function of the respiratory system.
The Great White Shark employs a specialized breathing method known as obligate ram ventilation. “Obligate” signifies that the shark must maintain constant forward motion to force water into its mouth and across the gill surfaces. If the Great White stops swimming, the water flow ceases, and the shark begins to suffocate. This adaptation is directly linked to the shark’s high metabolic rate and active, fast-swimming nature, which demands a continuous supply of oxygen.
This mechanism contrasts sharply with the “buccal pumping” used by more sedentary sharks, such as the Nurse Shark. Sharks that use buccal pumping can draw water over their gills by actively moving their jaw and pharyngeal muscles while stationary. Great White Sharks have either lost the ability to buccal pump or possess heavily reduced spiracles, which are small breathing openings behind the eyes that assist in stationary respiration in other species. This physiological constraint means the Great White Shark is perpetually tied to a life of movement, even during periods of rest.
Physical Features and Shark Gill Variation
The Great White Shark’s gill structure is characteristic of the class Chondrichthyes, which includes sharks and rays. Unlike bony fish, which have a single, firm gill cover called an operculum, the shark’s gill openings are open slits that lack this protective bony covering. This design reflects the shark’s cartilaginous skeleton.
While the five-gill configuration is standard for the Great White and most modern sharks, evolutionary diversity exists within the broader shark family. Certain species, belonging to the ancient order Hexanchiformes, possess a greater number of gill slits. Sixgill and Sevengill sharks are named for their possession of six or seven gill slits on each side, respectively. This variation demonstrates the evolutionary range within the Chondrichthyes class.