Electronic Theses and Dissertations

Date of Award

2014

Document Type

Thesis

Degree Name

M.S. in Biological Science

Department

Biology

First Advisor

Glenn R. Parsons

Second Advisor

Brice P. Noonan

Third Advisor

Richard Buchholz

Relational Format

dissertation/thesis

Abstract

Bite force can provide valuable information regarding the physiological ecology of an organism. However, there have been few studies wherein bite force in sharks has been considered. Herein I report on a study of the bite force of four species of sharks with particular emphasis on that of the atlantic sharpnose shark, rhizoprionodon terraenovae. Among the four species examined, blacktip shark, carcharhinus limbatus bite force was significantly higher than that of sharpnose, rhizoprionodon terraenovae. There was no significant difference between the bite force of those species compared with the same for finetooth shark, c. Isodon and spinner shark, c. Brevipinna. Within atlantic sharpnose sharks, I examined both voluntary and involuntary (obtained using jaw musculature stimulation) bite force measurements, and I investigated differences in bite force between size, sex, season, gape, and capture method. Additionally, I examined bite force differences between anterior and posterior positions in the jaw, and considered correlations between various head morphometrics and anterior bite force. Sharpnose sharks, ranging between 55.1 – 105.5 cm, had an anterior bite force between 4.4 – 60.2 n, and a posterior force of 20.9 – 102.8 n. There was no significant difference between the different methods used to determine bite force. Adult females had a greater anterior force than adult males, but there was no difference in posterior force. Anterior force was found to be weakest in the summer months and highest in the spring and fall. As gape increased the anterior bite force increased, with the greatest force found between 70 – 80% of maximum gape. Longlining captured sharks produced significantly lower bite force when compared to hook and line capture.

Included in

Zoology Commons

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