title: CT scans and 3D reconstructions of Florida manatee (Trichechus manatus latirostris) heads and ear bones.
abstract: The auditory anatomy of the Florida manatee (Trichechus manatus latirostris) was investigated using computerized tomography (CT), three-dimensional reconstructions, and traditional dissection of heads removed during necropsy. The densities (kg/m3) of the soft tissues of the head were measured directly using the displacement method and those of the soft tissues and bone were calculated from CT measurements (Hounsfield units). The manatee's fatty tissue was significantly less dense than the other soft tissues within the head (p<0.05). The squamosal bone was significantly less dense than the other bones of the head (p<0.05). Measurements of the ear bones (tympanic, periotic, malleus, incus, and stapes) collected during dissection revealed that the ossicular chain was overly massive for the mass of the tympanoperiotic complex.
authors.affiliation: Department of Oceanography, Florida State University, 529 OSB W. Call Street, Tallahassee, FL 32306-4320, United States. marie.chapla@noaa.gov
authors.forename: Marie E
authors.initials: ME
authors.lastname: Chapla
authors.forename: Douglas P
authors.initials: DP
authors.lastname: Nowacek
authors.forename: Sentiel A
authors.initials: SA
authors.lastname: Rommel
authors.forename: Valerie M
authors.initials: VM
authors.lastname: Sadler
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D000818:Animals; D015519:Bone Density; D004210:Dissection / Q000379:methods; D004429:Ear Ossicles / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D004431:Ear, External / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D004432:Ear, Middle / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D005260:Female; D006257:Head / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007188:Incus / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D008297:Male; D008307:Malleus / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D009132:Muscles / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D012886:Skull / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D013199:Stapes / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D020457:Trichechus manatus / Q000033:anatomy & histology*