1. HEARING AND AGE ESTIMATION IN TWO SPECIES OF ARCTIC WHALE
- Author
-
Sensor, Jennifer Dawn
- Subjects
- Aging, Biological Oceanography, Biology, Cellular Biology, Histology, Wildlife Management, Neurobiology, Cetacea, Odontoceti, Mysticeti, Delphinapterus leucas, hearing, cochlea, inner ear, spiral ganglion, Balaena, Tympanic bulla, GLGs, LAGs, Arctic, stable isotopes
- Abstract
This dissertation provides baseline information about the inner ear of beluga and bowhead whales, focusing on cell number and density of the spiral ganglion and the cross-sectional area of Rosenthal's canal along the length of the cochlea. Cochlear morphometric information is provided. The spiral ganglion is investigated for signs of trauma, as neural degeneration in the spiral ganglion is not immediate upon sound exposure (as it is in other cochlear regions) allowing documentation of long term damage to the inner ear.I also present a new method of age estimation for bowhead whales through counting GLGs within the periosteal region of the involucrum of the tympanic bulla. I characterize the different parts of the involucrum isotopically and histologically. The results are compared to life history parameters and to estimation methods that use baleen isotopes and baleen length.
- Published
- 2017