Analysis of fish tooth roughness reveals insights into underwater eating habits

Posted by ap507 at Dec 14, 2015 11:20 AM |
University of Leicester researchers develop new technique to analyse fish diets

Issued by University of Leicester Press Office on 14 December 2015

Contact pressoffice@le.ac.uk to request images.

Scientists at the University of Leicester have developed a technique to perform dietary analysis of fish by analysing microscopic tooth wear.

The process, which involves taking moulds of the teeth similar to those a dentist might take, used focus variation microscopy to digitally capture details of the tooth surfaces, zooming in to an area just 1/7th of a mm in width - around the same as that of a human hair.

These 3D data allowed the researchers to distinguish between different diet by comparing the roughness and shape of the tooth surface on a tiny scale.

This offers a new method to analyse fish diets based on the fossil record.

The results are published in the journal Surface Topography: Metrology and Properties.

Mark Purnell, Professor of Palaeobiology at the University of Leicester’s Department of Geology, said: “We had a specific question: is it possible to use the microscopic wear patterns on fish teeth to work out what they eat.

“It’s interesting as the shape of teeth is often used to infer the diet of fossil species – but we’ve seen with living species that they don’t always eat what their teeth seem to be best adapted for.”

The researchers suggest that judging the diet of a species by tooth shape can be misleading.

Professor Purnell explained: “We saw this in this work, where the Sheepshead seabream and the Atlantic Wolffish have quite similar teeth, which look like they are most suitable for a shell-crushing predator.

“However the Sheepshead seabream, like its mammalian namesake, can have a diet that involves a significant amount of plant material.”

One of the populations of Sheepshead seabream the researchers analysed had such a plant-based diet, and they were able to identify difference in texture between populations with different diets.

The researchers also looked at different populations of cichlid fish, and where able to distinguish between wild fish with a shell-crushing diet (including snails) and pond raised fish fed a more controlled diet.

Professor Purnell said: “The tooth textures pick all this up and the range of species this technique seems to work for was also pleasantly surprising.”

Whilst this technique has been used before on land animals, the application to other fish species and sea mammals will allow researchers to investigate how diet controlled the evolution of aquatic creatures in the distant past.

The published version of the paper will be freely available online at: http://iopscience.iop.org/article/10.1088/2051-672X/4/1/014006

ENDS

Notes to editors:

For more information please contact Professor Mark Purnell on map2@le.ac.uk

Surface Topography: Metrology and Properties is an international forum for academics, industrialists and engineers to publish the latest research in surface topography measurement and characterisation, instrumentation development and the properties of surfaces.

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