Observations on the anatomy of the respiratory system of the river otter, sea otter, and harp seal. II. The trachea and bronchial tree

• Published in: Canadian Journal of Zoology
• Main Authors: Tarasoff, F. J., Kooyman, G. L.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1973
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Harp Seal
• Online Access: http://dx.doi.org/10.1139/z73-025; http://www.nrcresearchpress.com/doi/pdf/10.1139/z73-025

The trachea of the river otter and sea otter are morphologically similar to each other, whereas the trachea of the harp seal is relatively shorter and broader and has noncalcified overlapping cartilaginous rings and a relatively thicker lamina propria. The harp seal has fewer cartilaginous rings, the arms of which overlap dorsally in the cranial two-thirds of the trachea. The bronchial blanching patterns are similar in the river otter and sea otter, with the pennate-like branching of the lobar bronchi corresponding to the lobes of the lungs. In the harp seal there are more dichotomous branchings of the lobar bronchi, with close symmetry between the right and left lungs. Bronchiograms and dissections indicate that the numbers of subsegmental bronchioles increase from the river otter to sea otter to harp seal.