Dec 2, 2010 10:43 GMT  ·  By
The jaws of adolescent great white sharks may be too weak to capture and kill large marine mammals.
   The jaws of adolescent great white sharks may be too weak to capture and kill large marine mammals.

An international team of researchers carried out a new study that concluded that the jaws of adolescent great white sharks may be too weak to capture and kill large marine mammals.

Thanks to detailed computer simulations, they looked at the feeding behavior of two threatened shark species – the harmless gray nurse (sand tiger) and the ferocious great white.

Through digital models, the scientists observed that the jaws of the gray nurse are spring-loaded for a rapid strike on small, fast-moving fish, while the great white have jaws that are better suited for a powerful bite on any kind of prey, from small fish to large marine mammals.

Study co-author Dr Stephen Wroe, who heads the Computational Biomechanics Research Group in the UNSW School of Biological, Earth and Environmental Sciences, said that they “were surprised that although the teeth and jaws of our sub-adult great white shark looked the part and the muscles were there to drive them, the jaws themselves just couldn't handle the stress associated with big bites on big prey.”

Apparently, before great white sharks get to a length of almost 3 meters, they have poorly developed stiff mineralized cartilage, in other words, their jaws are weak.

UNSW doctoral student Toni Ferrara, the lead author of the article, said that “it is hard to believe, but at this size great whites are basically just awkward teenagers that can't hunt large prey very effectively.

“It seems paradoxical that the iconic jaws of great white sharks - made infamous by the classic Steven Spielberg movie Jaws - are actually rather vulnerable when these sharks are young.

“Great white sharks are not born super-predators, they take years to become formidable hunters.”

But once a shark becomes an adult, it can maintain high bite forces no matter how widely its jaws are open, because it has a unique jaw muscle arrangement that has made sharks ones of the most successful predators ever.

This is actually the first study of its kind to use highly complex 3D computer models and advanced engineering techniques to analyze the way that different sharks hunt and kill prey.

“This study may also explain why many of the shark attacks off NSW are aborted after a single exploratory bite, as the great whites involved are usually juveniles that might sustain jaw injury if they persevered with the attack,” said co-author Dr Vic Peddemors, of the NSW Cronulla Fisheries Research Centre of Excellence.

The 2.5 meter great white shark that was used for the study, had been caught by the NSW Bather Protection Program.

The new study is published in the Journal of Biomechanics.