Many Rows of Razor Sharp Teeth

I have always been fascinated by sharks.  They have a very powerful jaw and the reason why most people fear sharks is because they can bite.  I was surprised to find out that the shark with the most powerful bite is not the tiger shark or the great white.  Scientists from the University of South Florida report that sometimes the size of the shark can be misleading in respect to how strong they can bite.  Bull sharks have been shown to have the strongest bite with an average force of 6000 N in the back of their mouths and 2000N in the front.  Researchers know that the strong bite force is needed to crunch turtle shells.  They also think that it has something to do with the fact that bull sharks have a very high tolerance for freshwater.  Their bite strength may be needed for the things they consume in freshwater.  This jaw strength combined with their many rows of razor sharp teeth can lead to a painful bite into many other organisms in the ocean.

Sharks have as many as 5 to 15 rows of teeth behind their main row.  Their teeth are usually in functional service for about a week, but can be lost as early as 24 hours.  They can be lost so fast because their teeth are not attached with roots like ours.  As the main row is lost, teeth from the next row move in.

I have always enjoyed looking for these teeth along the beach.  I have been to the beaches of South Carolina about 8 times and usually find about 20-30 teeth each time I go that range in size and shape. In looking at the teeth I have collected , I wanted to learn how to identify what type of shark they came from.  I found this key that was helpful in determining what shark the tooth came from.  There are a number of other keys online.



I have found teeth from the great white, tiger, sand, lemon and bull sharks.  Hopefully we will have some time to search the beaches for teeth as a class on our trip!