24-26 November 2021
Online
Australia/Sydney timezone

Jaws caught on the IMBL

25 Nov 2021, 13:30
15m
Online

Online

Oral Biomedicine, Life science & Food Science Biomedicine, Life science & Food Science

Speaker

Dr Daniel Hausermann (Australian Synchrotron (ANSTO))

Description

Maturational changes in feeding behaviour among sharks are associated with increased mineralisation of the teeth and jaws, but this relationship has only been demonstrated in a few species. Large, highly mobile shark species are rarely available for detailed anatomical study, despite their importance for ecological health and widespread interest among the general population. We examined the crania, jaws, and teeth of two great white sharks (Carcharodon carcharias), a 2.3 m juvenile and a 3.2 m young adult.

The CT scans used a 230 keV (mean energy) polychromatic beam from the 4 Tesla wiggler, with a filtration of 6mmAl, 6mmCu, 3mmMo and 3mmPb. The detector was a Teledyne-Dalsa Xineos 3030HR with 100µm pixels, a width of 300mm, and a 1mm CsI converter for high efficiency at high energy. Image noise was reduced by collecting 18,000 projections per rotation to deliver an image quality good enough to segment out different tissue types. With a beam size of 300mm x 35mm, the shark head was covered by ‘tiling’, and stitching the tiles, with the full-head image made up of two columns and 21 tiles, to image a 600mm x 520mm area. Total scan time was 9 hours.

The heads were also imaged using conventional CT and 7 Tesla MRI for finite element modelling of bite forces produced by the jaw musculature. These results will be compared with measurements of the difference in mineralisation of tooth and jaw cartilage between the two specimens to assess developmental changes in tooth and jaw hardness as the animals shift their diets from largely fish-based (juvenile) to larger prey, such as seals, scavenged whales and surfers (adults).

Condition of submission Yes
Pronouns She/Her
Presenter Gender Woman
Students Only - Are you interested in AINSE student funding No
Which facility did you use for your research Australian Synchrotron
Level of Expertise Expert
Do you wish to take part in the Student Poster Slam No

Primary authors

Dr Anton Maksimenko (Australian Synchrotron (ANSTO) ) Dr David Reser (School of Rural Health, Monash University ) Dr Daniel Hausermann (Australian Synchrotron (ANSTO)) Dr Michael De Veer (Monash Biomedical Imaging, Monash University) Dr Olga Panagiotopoulou (Department of Anatomy & Developmental Biology, Monash University) Dr Charlie Huveneers (College of Science and Engineering, Flinders University) Dr David Wright (Department of Neuroscience, Monash University) Dr Chris Hall (Australian Synchrotron)

Presentation Materials

There are no materials yet.
Your browser is out of date!

Update your browser to view this website correctly. Update my browser now

×