Did you know that sharks are successful outside movie theaters too?

Did You Know…

…that Sharks Are Successful Outside Movie Theaters Too?

Did you know that sharks are successful outside movie theaters too? Suspenseful music, a lone swimmer – and from below comes a great white shark... 40 years after its premiere, Steven Spielberg's film "Jaws" still has the power to trigger goose bumps. Science has long refuted the myth of the man-eating monster. Nevertheless, the odd incident still occurs. After all, Carcharodon carcharias is the largest predatory fish in the world. And it will attack, especially if it feels threatened. But for this species, man is a much greater enemy than any other fish. Existing stocks are under threat due to targeted fishing as well as by-catch by commercial fishing fleets.

It is not only in horror films that the white shark's teeth are useful – they are also suitable for scientific research. By comparing teeth from living sharks of this and other species with fossils, a team at Cornell University in the USA can establish how predecessors lived. The teeth are the only thing that remain of a shark after it dies, since only rarely is the cartilaginous skeleton fossilized in its entirety.

With the aid of computer tomography using X-ray microscopes, the researchers under the leadership of Professor Willy Bemis examine the anatomy, development and evolution of this family of fish. While in the past researchers could only examine the external shape, they can now see inside the teeth too – without destroying the samples. This new technology allows for the investigation of tissue and blood vessels, as well as the growing "replacement teeth." Using ZEISS Xradia X-ray microscopes, countless questions can be answered – even very basic ones such as the diets of the various species.

Professor Bemis has already collected hundreds of shark jaws and thousands of teeth, some of which are on loan from institutes around the world. It remains to be seen what other secrets the researchers can unlock from these sharks' teeth – secrets of a family which has existed for almost 400 million years and has been exceptionally successful in evolution, not only at the box office.

6 November 2013