Sharks don't have scales but they have something different instead - Dermal Denticles, literally "skin teeth" rows and rows of tiny teeth made out of dentine, the same stuff as teeth!
The dermal denticles are embedded in the skin and face backwards and are all aligned (this is why sharks feel smooth when you stroke them from head to tail but rough when you stroke them backwards. Many aquariums have petting tanks where you can pet small harmless sharks e.g.nurse sharks, dogfish etc). They often also have the same shape as the teeth of the shark (though not all).
The dermal denticles are embedded in the skin and face backwards and are all aligned (this is why sharks feel smooth when you stroke them from head to tail but rough when you stroke them backwards. Many aquariums have petting tanks where you can pet small harmless sharks e.g.nurse sharks, dogfish etc). They often also have the same shape as the teeth of the shark (though not all).
The denticles do several things :
- Protect the shark
- Help it swim through the water more easily
The dermal denticles help reduce the friction between the shark and the water (they help it slip through the water more easily).
posted by:
Medusa R. Acabo
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