how many teeth does a shark have from birth?

Answer 1

Okay, I will have to answer this one, since it is an elasmobranch question and since Cali starred it.

Your question is a indeed a really good one, and you received some very good answers. Elasmobranch (sharks, skates, and rays) teeth originate indeed embryologically speaking in scales. In fact, the placoid scale that cover the body of a shark are just like teeth in that they have a pulp cavity, a dentine layer covered by a tip of enamel. So, the answerer who spoke of shark teeth to be scales is not entirely wrong - maybe just a timy bit inacurate. Sharks do have teeth, and their teeth are not only found in the mouth.

Now, to quickly answer your question: Sharks are born with a complete set of teeth. As numerous answerers here have said before me, sharks have polyphydont dentition, which means that teeth are constantly renewed and old ones being discarded. As Cali pointed out, an animal with that kind of dentition can go through literally thousands of teeth during its lifetime. these numbers are approximations based on tooth loss rate in captive sharks and age determination in the same or a similar species.

Species specific traits are of course what makes an exact answer to your question extremely difficult. Sharks vary in their biology, in their ecology and so also in their dentition. While all sharks are polyphydont, shape and function of their teeth differ dramatically as a function of their ecology, and most importantly, their preferred prey.

In some species, this prey is actually hunted even before birth. A variety of lamnoid sharks are what shark biologists call oophagous, which means that during large parts of their embryological development these animals feed on eggs that the mother keeps ovulating during pregnancy. These sharks have functional teeth already as embryos in utero! One species in particular, the sandtiger shark (Carcharias taurus), is not only oophagous, but before it starts eating the eggs in the uterus it first hunts and devours its siblings in the embryophagous phase of development. Sandtingers, like most lamnoid sharks, have fully erect and functional teeth already in the uterus and by time of birth are equipped with a full set of teeth.

I hope this might help a little.

Answer 2

I don't think anyone has actually counted how many teeth a shark goes through in its lifetime. We do know they replace their teeth every 6-8 weeks allowing the front row to drop out and a new row to come up behind. They typically have 2-4 rows of teeth showing at any one time. This means that the shark goes through thousands of teeth and hundreds of rows in a lifetime. Some sharks have grinding plates and some sharks like the basking shark don't use their teeth to feed so we don't know too much about their teeth either.

Answer 3

Sharks have hundreds or thousands of teeth, and these teeth develop even before they're born (shark pups are already prepared to feed and fend for themselves, since there is no parental care).
The teeth are arranged in rows. Each row comprises one or a few "functional" teeth at a time (the ones situated in the outer or 'front' row), whereas the rest of them are replacement teeth that grow on the lingual (internal) side of the jaws and move outwards like a conveyor belt.
The replacement is continuous and there are many generations of teeth (this is called polyphyodonty), since the teeth are not firmly attached to alveoli (=cavities) in the jaws like our own teeth, but lie over the jaw cartilage and are more or less loosely attached to it by connective tissue (this condition is called acrodonty).
Thus, some teeth are lost when biting, while others are simply shed, and all are continuously replaced (just like their scales, by the way).

Although the number of teeth is usually quite stable for a given species, there are ontogenetic changes (changes between young and adults) in the number and shape of teeth.
Here's a rather dated publication about shark teeth replacement: http://www.biolbull.org/cgi/reprint/95/1/100

Here's more general information:
http://seagrant.gso.uri.edu/factsheets/sharks.html


PS. Note to the UK YA Team: a miscategorized question is not exactly a good example for the "Best of", guys ;-)
PS 2. Congrats to the Answerer above who managed to copy&paste from so many sources without citing a single one.

Answer 4

u r in the wrong section just like me and a shark can have up to six rows of 32 teeth in each from birth and when they get older the new teeth grow in and push the old ones out

Answer 5

I know they have them before they are born because there is a species of shark in which 2 or 3 embryos form but only one is born - it eats the others in the womb. Not joking, honest, can't remember the species, sorry. Talk about survival of the fittest. No wonder they do so well.

Answer 6

well you do not know exactly how many teeth sharks have but i think about 100 to 500 teeth

Answer 7

I wouldn't fancy getting close enough to count, but I did hear of a scientist getting bitten on the finger by a baby shark that was still in the womb, while he was carrying out a post mortem on its pregnant mother.

Answer 8

A shark may grow and use over 20,000 teeth in its lifetime!

Answer 9

None - sharks don't have any teeth. They are often refered to as 'teeth' but they are not. They are scales that grow and turn backwards and open out. The only have very sharp scales - no teeth.

Answer 10

my solicitor said he had no teeth when he was born

but soon got his gnashers

hope this helps

as to a sea shark i have never put my hand in its mouth to find out
so sorry for not knowing that