Functional anatomy of the middle and inner ears of the red fox, in comparison to domestic dogs and cats.
Journal of anatomy
MetadataShow full item record
Malkemper, E. P., Mason, M., & Burda, H. (2020). Functional anatomy of the middle and inner ears of the red fox, in comparison to domestic dogs and cats.. Journal of anatomy, 236 (6), 980-995. https://doi.org/10.1111/joa.13159
Anatomical middle and inner ear parameters are often used to predict hearing sensitivities of mammalian species. Given that ear morphology is substantially affected both by phylogeny and body size, it is interesting to consider whether the relatively small anatomical differences expected in related species of similar size have a noticeable impact on hearing. Here, we present a detailed anatomical description of the middle and inner ears of the red fox Vulpes vulpes, a widespread, wild carnivore for which a behavioural audiogram is available. We compare fox ears to those of the well-studied and similarly-sized domestic dog and cat, taking data for dogs and cats from the literature as well as providing new measurements of basilar membrane length and hair cell numbers and densities in these animals. Our results show that the middle ear of the red fox is very similar to that of dogs. The most obvious difference to that of the cat is the lack of a fully-formed bony septum in the bulla tympanica of the fox. Cochlear structures of the fox, on the other hand, are very like those of the cat, while dogs have a broader basilar membrane in the basal cochlea. We further report that the mass of the middle ear ossicles and the bulla volume increase with age in foxes. Overall, the ear structures of foxes, dogs and cats are anatomically very similar, and their behavioural audiograms overlap. The results of several published models and correlations, which use middle and inner ear measurements to predict aspects of hearing, did not always match well with audiogram data, however, especially when it came to the sharper tuning in the fox audiogram. This highlights that while there is evidently a broad correspondence between structure and function, it is not always possible to draw direct links when considering more subtle differences between related species.
Ear, Middle, Animals, Dogs, Foxes, Cats, Body Size, Organ Size, Phylogeny, Ear, Inner, Hair Cells, Auditory
This work was funded by the German National Academic Foundation (Studienstiftung des deutschen Volkes, doctoral scholarship to E.P.M.) and the Grant Agency of the Czech Republic (project. nr. 506/11/2121 to H.B.; project no. 15-21840S to H.B. and E.P.M.). The Human Anatomy Teaching Group, Department of Physiology, Development & Neuroscience, funded the CT-scanning.
External DOI: https://doi.org/10.1111/joa.13159
This record's URL: https://www.repository.cam.ac.uk/handle/1810/300731