How many teeth do sharks have?
There are about 470 species of sharks in the world.
Of those, over 20% have multiple rows of teeth that can be replaced when lost or broken.
The average number of teeth for this type is about 300, while a single row contains only a few dozen.
They lose and gain new rows approximately every 5-7 days.
As the tooth on the outer edge of the row is shed, a new one forms to take its place.
The teeth in multiple rows are not automatically replaced by new ones.
However, they grow and move forward to replace those that fall out.
The replacement rate varies depending on where the shark is in its life cycle.
It can also depend on the type of food a particular species prefers.
Different Teeth Growth For Different Sharks
For example, sand tiger sharks can go through about 15,000 teeth over their 20 to 25-year lives.
They have seven or eight rows at any given time bearing four to six teeth each.
That’s up to 60 new teeth a day.
They often lose and replace the same tooth several times while waiting for it to fall out or while it is damaged during eating.
The teeth travel forward over time, pushing older ones further back in the mouth until eventually they are thrown out.
Greenland sharks (Somniosus microcephalus) may only go through about 5,000 teeth over the course of their nearly 400-year life spans (scientists believe they can live up to 200 years).
They only have two rows bearing about 25 teeth each.
These sharks only lose and replace about one tooth per day, so it can take more than 10 years for a replacement tooth to travel by pushing the older one further back.
These sharks grow about one tooth per year, so it’s not clear why they have fewer teeth than the sand tiger shark.
Sharks are able to lose and regrow teeth because of their ability to heal quickly.
The cells in their bodies are constantly renewing themselves so the process doesn’t take much time at all for damaged tissues to become new.
Sharks can heal from severe injuries that would be fatal for other animals in just a few months.
