Sharks possess a highly specialized dental system, with many species featuring incredibly sharp teeth adapted for their predatory lifestyle. These teeth are continuously maintained for effective prey capture.
Understanding Shark Tooth Structure
The sharpness of a shark’s tooth stems from its unique composition and structural design. Each tooth has a core of dentine, a hard, bone-like tissue. Encasing this core is an outer layer known as enameloid, one of the hardest mineralized tissues found in animals. This enameloid is primarily composed of fluorapatite, a calcium phosphate mineral that makes the tooth durable. Fluorapatite is even harder than the hydroxyapatite that forms human tooth enamel, resisting wear. The enameloid layer is also approximately six times harder than the inner dentine, creating a robust cutting edge.
Varied Tooth Designs and Their Purpose
The term “razor sharp” does not describe all shark teeth uniformly, as their designs vary significantly based on diet and hunting strategies. For instance, sharks that pursue agile, slippery prey like mackerel or squid often feature pointed, needle-like teeth. Species like the mako shark use these teeth to grasp fast-moving prey. Conversely, large predatory sharks, including the great white and tiger shark, possess triangular, serrated teeth. These teeth are shaped to cut through the tough flesh and bone of larger prey like seals, dolphins, or sea turtles. Their serrated edges function like a saw, enabling powerful shearing and tearing. Other sharks, often bottom dwellers, have evolved flat, crushing plates instead of pointed teeth. Nurse sharks and horn sharks, for example, use these flattened teeth to grind and crush the hard shells of crustaceans, mollusks, and sea urchins. Filter-feeding sharks like the whale shark have thousands of tiny, non-functional teeth, which are not used for biting but are vestigial structures.
The Conveyor Belt of Teeth
Sharks maintain their dental arsenal through a continuous tooth replacement system, often described as a “conveyor belt.” New teeth constantly develop in rows behind the functional teeth in the front of the jaw. As older teeth are lost or damaged during feeding, new teeth gradually move forward to take their place. This replacement process can occur rapidly, with some sharks replacing a lost tooth in as little as 24 hours. On average, a shark might lose at least one tooth per week, and species like the great white shark can replace up to 1,000 teeth annually. This constant regeneration ensures sharks always have sharp, effective teeth.