African Biodiversity pp 329-337 | Cite as
Middle Ear Ossicles as a Diagnostic Trait in African Mole-Rats (Rodentia: Bathyergidae)
Abstract
Within the family Bathyergidae (subterranean African mole-rats), Cryptomys and Coetomys are the most speciose genera. Whereas each species can be characterized karyologically and from mitochondrial gene sequence data genetically, most of them exhibit marked intraspecific polymorphism and an overlap in morphological and biometric traits making them very hard to discern for taxonomic studies. As a consequence, pelage colour, body size and craniometric characters are inappropriate for species diagnosis.
Here we report on a comparative morphological and biometric analysis of the auditory ossicles in seven species of Coetomys and one species of Cryptomys. While species can be identified by a unique combination of oto-morphological features, there is also a strong correlation between biometry of functionally relevant traits and the habitat. Middle ear biomechanical efficiency and hence hearing sensitivity appears to improve with increasing humidity of the habitat. This trend is evident even when comparing different populations at an intraspecific level.
Key words
functional morphology middle ear species diagnosis Coetomys Cryptomys BathyergidaePreview
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