We don't know if any fish sleeps in the sense that we sleep, i.e. sleep measured by an abrupt change in brain waves. I slammed on the brakes and put my hand out to catch the jaw before it hit the dashboard, so I was accidentally cut by the teeth. A baby whale shark is about 20 inches at birth, but the amazing thing about baby whale sharks is that a mother can give birth to about 300 at one time, the greatest number in a birth litter known of any shark. Most female sharks give birth to only a few babies at one time every few years. Sharks have layers of teeth so that if any are broken off, new sharp teeth can pop right in to replace them.
Some sharks can replace their front teeth every two weeks.
Sharks shed their teeth a lot, and that's why there are so many fossil teeth around. They can shed thousands of teeth over a lifetime and the teeth preserve well even when the rest of the shark decomposes. The Crown Prince is now the Emperor of Japan, and I have visited him several times in his palace in Tokyo. Yes, I love math, especially geometry. Math comes in very handy in marine biology and any other branch of science.