Sharks not big biters for their size, says study


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Sharks do not bite hard for their body size and can only do so because of their wide jaws and sharp teeth, according to a study by American and Belgian scientists.

Publishing the results of their study in a recent issue of the journal Physiological and Biochemical Zoology, Daniel Huber, Julien Claes, Jrme Mallefet and Anthony Herrel examine the scaling of bite force and head shape for ten species of sharks.

The authors tested the hypothesis that a high bite force in sharks is a result of a large body size as well as testing for morphological traits related to head and body size that are the best predictors of bite force across species.

The sharks they studied ranged in size from the Blackbelly lantern shark (Etmopterus lucifer), which reaches a maximum size of 47 cm, to the Great hammerhead shark (Sphyrna mokarran), which grows to 6.1 m in length.

The authors obtained data of tooth morphology and bite force for the ten species, before running a series of mathematical and statistical analyses.

Based on the results of their analysis, the researchers found that ...large sharks do not bite hard for their body size but attain large body size and consequently have large absolute bite forces. Bite force capacity is tightly correlated with head dimensions, with head width being a particularly good predictor of bite force across species.

They also found that sharks with relatively high bite forces for their body size also have relatively more pointed teeth in front of their mouths, although the exact significance of this needs to be further studied.

For more information, see the paper: Huber, DR, JM Claes, J Mallefet and A Herrel (2009) Is extreme bite performance associated with extreme morphologies in sharks? Physiological and Biochemical Zoology 82, pp. 20"28.