shark bites

[kylemar]

how come shark divers that are wearing the steel mesh suits don't get broken arms when the shark bites them? I realize why they don't get cut, but I think force is force. They should have a broken arm!

[Phage]

Yeah... if a large shark decides to take a nibble, they would get some bones mashed. At least they still have an arm!

[Gary T]

Sharks have very effective teeth. There's no need for them to also have powerful jaws. Furthermore, their skeleton is made of cartilage rather than bone, so there's some yield in their chomp.

[donkeyoatey]

This (http://www.elasmo.com/martin/bite.html) is just somebody's take on it, but it seems he has a little knowledge to back it up. He must know something if he can use a word like gnathodynamometer, right?:)

sharks often seem to nip onto unfamiliar objects gingerly, as though testing it for tactile cues; as such, a shark biting an unfamiliar object - such as a diver wearing a Neptonic chain-mail suit - may not clamp down with all the force or power it can muster

[Sock Munkey]

Originally posted by Gary T
Sharks have very effective teeth. There's no need for them to also have powerful jaws. Furthermore, their skeleton is made of cartilage rather than bone, so there's some yield in their chomp.

Sharks DO have a very powerful bite and their jaws are in fact composed of bone. Usually when people are bitten it's only a gentle "warning bite" to tell the person to leave, an expeimental tasting, or a case the shark mistaking the person for something else and in thsese cases they don't bite with full force and let go right away.

[Gary T]

Originally posted by Sock Munkey
Sharks DO have a very powerful bite...

I'd be interested in a cite for that. I haven't found anything that indicates their bite is of bone-breaking strength.


...and their jaws are in fact composed of bone.

That's just wrong. Every source states that their entire skeleton is made of cartilage. Now, I did find that there are various degrees of calcified reinforcement in their jaws, making them more bonelike. Still, the jaws aren't as hard and stiff as actual bone.

[mmmiiikkkeee]

It would depend on the size of shark and the size of bone being bitten (:rolleyes: ). You see great whites taking chuncks out of surf boards, which I would suspect requires more than just sharp teeth since boards don't slice nicely like meat does. Not sure if I'd want to test the strength of my rib cage in a set of jaws that I could crawl into, even if all the teeth were removed. But I don't think a 3 foot shark could crush your femur.

[Q.E.D.]

About Shark Bite Stregth (http://www.elasmo.com/martin/bite.html).

[donkeyoatey]

Did you read the thread, Q.E.D.?:rolleyes:

[Q.E.D.]

Originally posted by donkeyoatey
Did you read the thread, Q.E.D.?:rolleyes: I missed a link. So sue me.

[Cisco]

From here (http://animal.discovery.com/convergence/safari/shark/expert/expert14.html):

or example, during one bite test the highest force applied by a single tooth was 60 kilograms (132 pounds). Since it was estimated that the 60 kilograms were applied over an area of 2 square millimeters, this means a loading of 30 kilograms per square millimeter. This equates to a force of 3 metric tons (6,000 pounds) per square centimeter!

Shark bites are incredibly powerful. If any other animal holds the bite power record it's only because larger sharks either break the measuring equipment when they bite it or they can't be bothered to cooperate.

[Q.E.D.]

The Dental Science Handbook published by the American Dental Association (1970) gives bite pressures by humans as great as 15 tons per square inch - 83% as strong as the greatest pressure recorded thus far for any shark. From my link above.

A shark's bite is more devastating, because 1) it's mouth is larger, and 2) because the teeth are sharper.

[donkeyoatey]

Originally posted by Q.E.D.
From my link above.



Really. Guess I better yield to the poster with the higher post count.
Originally posted by Q.E.D. I missed a link. So sue me.
Up to that point there were 6 posts after the OP and one link. Not a large amount of reading.

And everything I found says [b]Gary T[//b] is correct about cartilage (http://www.ucmp.berkeley.edu/vertebrates/basalfish/chondrintro.html):Sharks, skates, rays, and even stranger fish make up the Chondrichthyes, or "cartilaginous fish." .......Members of the Chondrichthyes all lack true bone and have a skeleton made of cartilage

From here (http://www.ucmp.berkeley.edu/vertebrates/basalfish/chondrintro.html) : The sharks, rays, and chimaeras make up the second group of fishes, the Class Chondrichthyes. Sharks are one of the earliest known jawed fishes. They have an upper and lower jaw made of cartilage.

[Cisco]

First of all Donkey, this isn't a penis measuring contest. There's no reason to "yield" to anyone and I don't see how post count is a factor.

Now, from Merriam Webster::

Main Entry: 1bone

1 a : one of the hard parts of the skeleton of a vertebrate b : any of various hard animal substances or structures (as baleen or ivory) akin to or resembling bone

Main Entry: car·ti·lage

1 : a usually translucent somewhat elastic tissue . . .




I think shark's jaws are much more accurately described as bone than as cartilage.

[Gary T]

Originally posted by Cisco
I think shark's jaws are much more accurately described as bone than as cartilage.

For some reason every authority in the field disagrees with that thought.

[donkeyoatey]

Originally posted by Cisco
First of all Donkey, this isn't a penis measuring contest. There's no reason to "yield" to anyone and I don't see how post count is a factor.

I think shark's jaws are much more accurately described as bone than as cartilage.

First of all Cis, what Gary T just said.
Second, I quoted and cited a link in the 3rd post in the thread, then [Q.E.D.] cited the same link 4 posts later. I took exception, he took exception to that. It's been done before. Then he cites said link "From my link above".
:rolleyes: to both of you.