Asymmetry in the skull of the harbour porpoise Phocoena phocoena (L.) and its relationship to sound production and echolocation

• Published in: Canadian Journal of Zoology
• Main Authors: Yurick, D. B., Gaskin, D. E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1988
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Pacific; Harbour porpoise; North Atlantic; Phocoena phocoena
• Online Access: http://dx.doi.org/10.1139/z88-056; http://www.nrcresearchpress.com/doi/pdf/10.1139/z88-056

Cranial asymmetry in the harbour porpoise Phocoena phocoena (L.) was studied using a series of 115 skulls obtained from animals from both sides of the North Atlantic and the east coast of the North Pacific. The degree of sinistrad asymmetry or "skew" did not differ significantly between these three populations. Contrary to an earlier report in the literature, skew was not found to be correlated with skull length or, by implication, age. This result is in accord with the necessity for precocious development of the nasal sac complex and associated structures in this species, which inhabits an environment in which the aural and acoustic faculties are of paramount importance.