Monday, May 3, 2010
How are Sharks Different From Other Fish?
Sharks are unique in several different ways:
1. They are made up entirely of cartilage which makes establishing a fossil history of these fish impossible.
2. Their skin is covered with denticles, which are tooth-like projections from the skin instead of scales.
3. They have no swim bladder. A very oily liver also provides buoyancy
to compensate for the lack of a swim bladder.
4. The jaw of a shark can be unhinged to open very wide while feeding. They also can
have as many as 8 rows of teeth.
5. Whenever a shark loses a tooth, another one moves up to take its
place. A shark can go through up to 2,400 teeth a year.