title: The guttural pouch is not present in the white rhinoceros (Ceratotherium simum); morphology of the eustachian tube and nasopharynx.
abstract: The nasopharynx and eustachian tube (auditory tube) were morphologically examined in the white rhinoceros. The narrow nasopharynx cavity was enlarged dorsoventrally. The most lateral part of both sides sharply rises in a dorsal direction and the volume is estimated at 173 cc. The eustachian tube is 145 mm in length from the auditory bulla to the nasopharynx. The hyaline cartilage is well-developed in the middle region of the eustachian tube wall. The results demonstrated that the white rhinoceros does not have a guttural pouch. We suggest that the occurrence of the guttural pouch may not be dependent on the phylogenetic status of perissodactyls such as horse, donkey and tapir.
authors.affiliation: Department of Zoology, National Science Museum, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Endo
authors.lastname: Manglai
authors.forename: M
authors.initials: M
authors.lastname: Fujisawa
authors.forename: M
authors.initials: M
authors.lastname: Kurohmaru
authors.forename: Y
authors.initials: Y
authors.lastname: Hayashi
mesh_terms: D000818:Animals; D002356:Cartilage / Q000033:anatomy & histology / Q000166:cytology; D005064:Eustachian Tube / Q000033:anatomy & histology*; D008297:Male; D009305:Nasopharynx / Q000033:anatomy & histology*; D010527:Perissodactyla / Q000033:anatomy & histology*; D010802:Phylogeny; D012886:Skull / Q000033:anatomy & histology