Geometric and Morphometric Analysis of the Auditory Ossicles in the Red Fox (Vulpes vulpes)

SIMPLE SUMMARY: The aim of the study was to determine the morphological and morphometrical features of the auditory ossicles in the red fox. Moreover, for the first time, shape analysis was performed on all the middle ear bones by geometric morphometry. The auditory ossicles play a vital role in transmitting sound waves through the middle ear. The malleus was considered to be the largest bone, with three distinctive processes. The overall shape of the incus was found to be similar to that in other mammals. The presence of a prominent muscular process was noted on the head of the stapes and the convex base which closes the window of the inner ear. ABSTRACT: The use of carnivores as experimental models in auditory biology has led to a significant improvement regarding our understanding of the structure and function of the ear. Considering that data regarding the anatomy of the middle ear in the red fox are rare, this study aimed to describe the morphological and morphometrical features of the auditory ossicles in the red fox, as well as to provide their shape characteristics by geometric analysis. Nine adult red foxes were used in the study. The malleus, incus and stapes were extracted from the middle ear, prepared, photographed and measured using the software. For the geometric analysis, 19 landmarks were used. Following Principal Component Analysis (PCA), PC1 was found to explain approximately half of all variance (incus: 49.97%; malleus: 49.93%; stapes: 58.49%). The study demonstrated the similar anatomical organization of the auditory ossicles in line with important morphometric and basic geometric data, which can contribute to this field and add a useful perspective to the literature.