Masticatory system integration in a commensal canid: interrelationships between bones, muscles and bite force in the red fox

• Published in: Journal of Experimental Biology
• Main Authors: Brassard, Colline, Merlin, Marilaine, Monchâtre-Leroy, Elodie, Guintard, Claude, Barrat, Jacques, Garès, Hélène, Larralle, Arnaud, Triquet, Raymond, Houssin, Céline, Callou, Cécile, Cornette, Raphaël, Herrel, Anthony
• Other Authors: Archéozoologie, archéobotanique : sociétés, pratiques et environnements (AASPE), Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Mécanismes Adaptatifs et Evolution (MECADEV), Laboratoire de la rage et de la faune sauvage de Nancy (LRFSN), Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES), Ecole Nationale Vétérinaire de Nantes, Université d'Angers (UA), Direction départementale des services vétérinaires de la Dordogne, Office National de la Chasse et de la Faune Sauvage (ONCFS), Université de Lille, Institut de Systématique, Evolution, Biodiversité (ISYEB ), Muséum national d'Histoire naturelle (MNHN)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Bases de données sur la Biodiversité, Ecologie, Environnement et Sociétés (BBEES), Ministère de l'Enseignement supérieur, de la Recherche et de l'Innovation
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: Vulpes vulpes; Skull; Mandible; Jaw muscle architecture; Geometric morphometrics; Domestication; MESH: Bite Force; MESH: Foxes; [SDV]Life Sciences [q-bio]; [SDV.BA.MVSA]Life Sciences [q-bio]/Animal biology/Veterinary medicine and animal Health; Lever; Canis lupus
• Online Access: https://hal-anses.archives-ouvertes.fr/anses-03292603; https://doi.org/10.1242/jeb.224394

International audience 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 in terms of understanding the impact of artificial selection. Here, we explored 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 jaw shape in 68 foxes. We used a static lever model and bite force estimates were compared with in vivo measurements of 10 silver foxes. Our results show strong relationships exist between cranial and mandible shape, and between cranial or mandible shape 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 probably reflects its greater specialisation towards biting. We then compared our results with data previously obtained for dogs (Canis lupus familiaris) to investigate the effect of domestication. Foxes and dogs differ in skull shape and muscle physiological cross-sectional area (PCSA). They show a similar amount of morphological variation in muscle PCSA, but foxes show lower variation in cranial and mandible 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.