Have you ever pet a shark (not that we condone shark petting!)?  Shark skin is smooth if you rub them from head to tail, but rough if you go tail to head.  This is because shark skin is actually teeth and this shark blog explains all about it...

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Shark armor... what is special about shark skin?

Shark skin is not made up of traditional fish scales.  Rather, they have minature teeth similar to shark teeth in general that interlock (see the close up picture above).  These scales are called "dermal scales".  Recent hydrodynamic research has show how these scales actually bristle like fur and push the water down the shark more efficiently and with less drag.  Check out this incredible talk by Bob Hueter about this miraculous research by clicking http://bit.ly/M5IALg.  Also, some zoologists suggest that early ancestors of sharks developed shark skin before developing teeth and that shark skin is the basis of teeth formation for all modern day animals.

For more interesting shark reads, just click on the link below:

Shark Facts & Info 

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