RT Journal Article
SR Electronic
T1 Masticatory system integration in a commensal canid: interrelationships between bones, muscles, and bite force in the red fox
JF The Journal of Experimental Biology
JO J. Exp. Biol.
FD The Company of Biologists Ltd
SP jeb.224394
DO 10.1242/jeb.224394
A1 Brassard, Colline
A1 Merlin, Marilaine
A1 Monchâtre-Leroy, Elodie
A1 Guintard, Claude
A1 Barrat, Jacques
A1 Garès, Hélène
A1 Larralle, Arnaud
A1 Triquet, Raymond
A1 Houssin, Céline
A1 Callou, Cécile
A1 Cornette, Raphaël
A1 Herrel, Anthony
YR 2021
UL http://jeb.biologists.org/content/early/2021/02/20/jeb.224394.abstract
AB The jaw system in canids is essential for defence and prey acquisition. However, how it varies in wild species in comparison with domestic species remains poorly understood, yet is of interest to understand the impact of artificial selection. Here we explore the variability and interrelationships between the upper and lower jaws, muscle architecture, and bite force in the red fox (Vulpes vulpes). We performed dissections and used 3D geometric morphometric approaches to quantify shape in 68 foxes. We used a static lever model and bite force estimates were compared with in vivo measurements of ten silver foxes. Our results show strong relationships exist between the cranium and mandible and the cranium or mandible on the one hand and muscles or estimated bite force on the other hand confirming the strong integration of the bony and muscular components of the jaw system. These strong relationships are strongly driven by size. The functional links between shape and estimated bite force are stronger for the mandible, which likely reflects its greater specialisation towards biting.We then compared our results with data previously obtained for dogs (Canis familiaris) to investigate the effect of domestication. Foxes and dogs differ in skull shape and muscle physiological cross-sectional areas (PCSA). They show a similar amount of morphological variation in muscle PCSA and mandible shape, but foxes show lower variation in cranial shape. Interestingly, the patterns of covariation are not stronger in foxes than in dogs, suggesting that domestication did not lead to a disruption of the functional links of the jaw system.