Skull of capybara (Hydrochoerus hydrochaeris) - morphometric parameters

ABSTRACT

Background: The capybara (Hydrochoerus hydrochaeris) is the largest rodent in the world. They are territorial animals,and live in social groups, commonly occurring in anthropized area, what has attracted the attention of researchers in relation to this animal species, since it is the host of the Amblyomma cajennese tick that transmits spotted-fever to humansand are responsible for severe impact on livestock and public health. The skull is a part of the axial skeleton that enclosingthe brain, sensory organs and digestive and respiratory structures. Moreover, the phenotypic appearance of the capybarahead depends on the shape of the skull. Thus, the aim of this study was to describe the reference values of cranial measurements of capybaras. The knowledge of morphometric parameters of skull is pivotal for veterinary treatment of pathologicalconditions and taxonomic affiliation.Materials, Methods & Results: Eight capybaras (Hydrochoerus hydrochaeris) skulls were used in this study, irrespectiveof age and sex. The skulls belonging to the anatomical collection of the Laboratory of Wildlife Anatomy and AnatomicalMuseum, Department of Anatomy, Universidade Estadual Paulista Júlio de Mesquita Filho, UNESP, Botucatu, São Paulo.A total of 35 morphometric parameters were performed using a digital caliper and 6 cranial indices were calculated. Allinvestigated features were expressed as mean ± standard deviation. Anatomically, capybara skull were elongated, rectanglelike and consisted of cranial and facial bones. The morphometric parameters were used to calculate the following craniometrics indices skull index (57.86 ± 3.62), cranial index (50.49 ± 2.08), facial index (49.22 ± 3.82), basal index (33.98 ±0.86), nasal index (26.73 ± 3.1), and the foramen magnum index (149.61 ± 1.07). Moreover, the facial part length (mean137.90 mm) and cranium part length (mean 87.76 mm) also were calculated. The facial part...(AU)