Submitter Withdrawn - Post notification 2024 Australian Marine Sciences Association Annual Meeting combined with NZMSS

The whole tooth: changes in tooth size and shape associated with ontogenetic changes in prey consumption by white sharks (Carcharodon carcharias) in Australia (#739)

Emily Hunt 1 , Yuri Niella 2 , Amy F. Smoothey 3 , Ezequiel M. Marzinelli 4 , David Raubenheimer 1 , Russell Bradford 5 , David J. Booth 6 , Victor M. Peddemors 3
  1. Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
  2. IMOS Animal Tracking Facility, Sydney Institute of Marine Science, Mosman, NSW, Australia
  3. New South Wales Department of Primary Industries, Sydney Institute of Marine Science, Mosman, NSW, Australia
  4. School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
  5. CSIRO Environment, Hobart, TAS, Australia
  6. School of the Life Sciences, University of Technology Sydney, Ultimo, NSW, 2007

White sharks Carcharodon carcharias change their diet as they increase in size, with larger sharks incorporating larger prey such as marine mammals. Several hypotheses have been proposed to explain the roles of developmental changes in jaw strength and musculature in enabling white sharks to transition to tough food such as whale blubber, however, surprisingly little is known about tooth structure and whether ontogenetic change in tooth shape and strength accompany this shift in diet. Here we describe the ontogenetic change in white shark teeth shape, surface area and thickness throughout the jaw. Using 75 white shark jaws from individuals ranging in size from 1.02 m to 4.65 m total length, we discover significant ontogenetic differences in tooth morphology which were related with the position in the jaw and shark total length, with lower and upper jaws on white sharks presenting two different tooth morphologies. Tooth morphology changed significantly with size, reflecting a heterodonty required to facilitate prey handling. Our analysis provides further evidence of the importance of teeth in enabling the ontogenetic broadening of nutritional niche previously described for white sharks.