Influential feeding dynamics of sharks and mathematical formulas to estimate the power of biting by morphological data

Document Type : Original Research Papers


1 MSc student, Biology Department, Ferdowsi University of Mashhad, Mashhad, Iran

2 Professor, Biology department, Ferdowsi University of Mashhad, Mashhad, Iran

3 PhD Candidate, Mechanical Engineering, Ferdowsi University of Mashhad, Iran


The mouths of some bony and cartilaginous fishes are located in the anterior part of their
bodies, with a slight variation in sharks, which have theirs located in the abdominal part. This
variation is evolutionary over time. The force exerted by the jaws of sharks in order to
dismember their prey can be examined from two origins: .The determined force exerted by teeth
and muscles and the force as a result of torque arm through jaw distance. Although sharks apply
less force compared to crocodile, their sharp teeth and mouth position provides much stronger
effect. Moreover, several species are characterized with heavier upper jaw and this enhances the
power. A mouth located in the anterior part of the body would have less force exerted. On the
contrary, human jaw is shorter, which applies much more force. This paper relates the prebranchial
length and power with preying strength. According to this survey, a couple of
predators were considered in terms of their mouth position, as well as different kind of feeding
and ecological characteristics. Morphological data on several sharks were extracted and
evaluated by MATLAB software to prove the following deductive hypothesis. The more the
support distance (prebranchial length) to concentrated force was, the stronger the shark preyed
on animals. The amount of torque had significant relationship with the lever distance and
concentrated force. Besides, several formulas have been recommended to estimate the bite force
and torque based on morphological characteristics.


Main Subjects

1. Dewi, R.S., Nurul Huda and R. Ahmad, 2011. Changes in the Physicochemical Properties,
Microstructure and Sensory Characteristics of Shark Dendeng Using Different Drying Methods.
American Journal of Food Technology, 6, 149-157.
2. Dosay-Akbulut, M., 2006. "The Determination of the Specific Characteristics on the
Immunosurveilance Against to Cancer Formation in Elasmobranchs". International Journal of
Cancer Research, 2, 119-123.
3. Escobar-Sanchez, O., F. Galvan-Magana and L.A. Abitia-Cardenas, 2011. "Trophic Level and
Isotopic Composition of δ13C and δ15N of Pacific Angel Shark, Squatina californica (Ayres,
1859), in the Southern Gulf of California, Mexico". Journal of Fisheries and Aquatic Science, 6,
4. Huber, D.R., C.L.Weggelaar and P.J. Motta, 2006. Scaling of bite force in the blacktip shark
(Carcharhinus limbatus). Zoology, 109, 109-119.
5. Schmidt-Nielson, K., 1984. Scaling: Why is Animal Size so Important? Cambridge University
Press, Cambridge.
6. Ferrara, T.L., P. Clausen, D.R. Huber, C.R. McHenry, V. Peddemors and S. Wroe, 2010.
Mechanics of biting in great white and sandtiger sharks. J. Biomech., 44, 430-435.
7. Motta, P.J., R.E. Hueter, T.C. Tricas and A.P. Summers, 2002. Kinematic analysis of suction
feeding in the nurse shark, ginglymostoma cirratum (Orectolobiformes, Ginglymostomatidae).
Copeia, 24-38.
8. Wainwright, P.C. and B.A. Richard, 1995. “Predicting patterns of prey use from morphology of
fishes.” Environmental Biology of Fishes 44, 97–113.
9. Summers, A.P., R.A. Ketcham and T. Rowe, 2004. Structure and function of the horn shark
(Heterodontus francisci) cranium through ontogeny: development of a hard prey specialist. J.
Morphol., 260, 1-12.
10. Whitenack, L. and P.J. Motta, 2010. Performance of shark teeth during puncture and draw:
implication for the mechanics of cutting. Biol. J. Linnean Soc., 100, 271-286.
11. P.J. Motta and D.R. Huber, 2009. "Bite Force and Performance in the Durophagous Bonnethead
Shark, Sphyrna tiburo." J. Exp. Zool., 313, 95-105.
12. Huber, D.R., J.M. Claes, J. Mallefet, A. Herrel, 2008b. "Is Extreme Bite Performance Associated
with Extreme Morphologies in Sharks?" Physiol Biochem zool 82, 20-28.
13. Huber, D.R., M.N. Dean and A.P. Summers, 2008a. "Hard prey, soft jaws and the ontogeny
offeeding mechanics in the spotted ratfish Hydrolagus colliei." J. R. Soc. Interface 5, 941–953.
14. Bourke, J., S. Wroe, K. Moreno, C.R. McHenry and P.D. Clausen, 2008. Effect of gape and tooth
position on bite force in the dingo (Canis lupus dingo) using a 3-dimensional finite
element approach. PLoS One, 3, 1-5
15. MARA, K. R., P. J. M. , et al., 2009. "Bite Force and Performance in the
DurophagousBonnethead Shark, Sphyrna tiburo." Journal of Experimental Zoology, 313, 95-105.
16. Tipler, P., 2004. Physics for Scientists and Engineers: Mechanics. 5th Edn., Oscillations and
Waves, New York.
17. Meriam, J.L., L.G. Kraige and W.J. Palm, 2002. Engineering Mechannics: Dynamics., John
Willey and Sons, 1, 203.