What Happens When a Shark
Loses a Tooth?
Sharks have diversified into 440 species, ranging in size from the small dwarf lanternshark, a deep sea species of only 17 centimetres (6.7 in) in length, to the whale shark, the largest fish, which reaches approximately 12 metres (39 ft 4 in) and which feeds only on plankton, squid, and small fish by filter feeding. Sharks are found in all seas and are common down to depths of 2,000 metres (6,600 ft). They generally do not live in freshwater, with a few exceptions such as the bull shark and the river shark which can live both in seawater and freshwater. They breathe through five to seven gill slits. Sharks have a covering of dermal denticles that protects their skin from damage and parasites, and improves their fluid dynamics so the shark can move faster.
The most famous feature of a shark is their teeth — specifically, the sharp, cutting teeth of such active hunters as the great white, blue and mako. Sharks have more than one set of teeth; some has as many as five. As the teeth are worn down, they fall out and are replaced by new ones growing behind. Keeping up with the shark’s growth, the new teeth are slightly larger than the ones they replace.
To humans, who have only two sets during a lifetime (the milk teeth and the adult), the rate at which sharks wear out and replace teeth is astounding. In a single decade, a tiger shark can shed as many as 20,000 teeth.
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