Researchers have found that sharks in fact have very weak jaws for their size and can bite through their prey only because they have very sharp teeth - and because they can grow to be so big.
"Pound for pound, sharks don't bite all that hard," Daniel Huber of the University of Tampa in Florida, who led the study, said
Dr Huber and the team studied 10 different shark species and measured the bites of small sharks such as sand sharks.
They tested larger sharks by knocking them out and using electricity to stimulate the jaw muscles.
They found sharks can do a lot of damage simply because their teeth are so sharp and their jaws are so wide. However compared with mammals they have incredibly weak bites for their size.
"Our analysis showed that large sharks do not bite hard for their body size, but they generally have larger heads," they wrote in their report, published in the journal Physiological and Biochemical Zoology.
Their studies of shark jaws show that lions or tigers win hands down when it comes to jaw strength but sharks prevail in the water because of their wide jaw size.
A 20ft (6-metre) great white shark can 'bite through anything that you come across,' the team added, noting that all species often have to resort to a sawing motion to break apart their prey.
Mammals have evolved much more efficient jaw muscles, Huber noted.
Dr Huber is part of a research group that has been studying the hunting prowess of great white sharks.
The team created an eight-foot great white shark in 3-D digital form that demonstrates how the animal functions, including measurements of the force of its bite.
Dr Huber said the research could lead to advances in protective swim wear and shark-proofing equipment. It could also contribute to the understanding of the flexible cartilage that forms sharks' skeletons.Original here