The Effects of Wear on the Morphology and Puncture Force of Shark Teeth

Sesler, Ryan

The Effects of Wear on the Morphology and Puncture Force of Shark Teeth

Persistent URL

https://dspace.allegheny.edu/handle/10456/56679

Author(s)

Sesler, Ryan

Date Issued

April 3, 2023

Abstract

Over the course of their lives, sharks replace thousands of teeth. Their teeth have been shown to be structurally and mechanically strong, resisting breakage or fracturing. Based upon this knowledge, the replacement of shark teeth and the frequency at which teeth are replaced could possibly be a consequence of tooth wear, not tooth failure. This project provides an analysis of how tooth wear can affect tooth morphology and puncture performance quantitatively in different species of shark. Individual puncture testing included five teeth each from five species of shark: Carcharhinus plumbeus, C. leucas, C. limbatus, Sphyrna mokarran, and Isurus oxyrinchus. Puncture testing of each tooth consisted of 400 repeated punctures into a standard prey item. The force of each puncture was recorded at specific intervals, ranging from between 10 to 30 punctures. At each interval, microscopic pictures of the tooth provided photographic evidence of physical wear along the cutting edges and tooth apex. Puncture testing displayed that visible tooth wear occurs over the 400 punctures, however, the rate at which the tooth wore down varied depending on the shark species and specific region of the tooth. Additionally, the puncture force required to complete one puncture increased over the entirety of testing. The data indicated that as the teeth wear down in small increments over time, the ability to function efficiently decreases. Future studies concerning shark tooth replacement rates and the maximum number of bites a tooth can withstand are necessary to complete the link between tooth wear and tooth replacement.

Major

Biology

Honors

Biology, 2023

First Reader(s)

Whitenack, Lisa B.