Aspects of the structure and composition of baleen, and some effects of exposure to petroleum hydrocarbons

• Published in: Canadian Journal of Zoology
• Main Authors: Aubin, D. J. St., Stinson, R. H., Geraci, J. R.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1984
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Balaenoptera physalus; Fin whale
• Online Access: http://dx.doi.org/10.1139/z84-032; http://www.nrcresearchpress.com/doi/pdf/10.1139/z84-032

The structure and composition of baleen from seven species of whales was studied using tensiometry. X-ray diffraction, and elemental analysis. Baleen was found to be composed principally of amorphous and α-keratin. Hydroxyapatite (bone mineral, Ca 10 (PO 4 ) 6 OH 2 ) was present in all species. Certain elements, notably manganese, copper, boron, iron, and calcium were more highly concentrated in the fibers than in the matrix of the plate. The breaking strength of baleen plates from fin (Balaenoptera physalus), sei (B. borealis), and grey (Eschrichtius robustus) whales was comparable to that of buffalo horn, in the range of 2−9 × 10 6 N∙m −2 . The stiffness of baleen was somewhat less than that of other keratinized tissues. Treatment with 10% (v/v) trichloroacetic acid for 8 days removed most of the calcium salts, denatured α-keratin, and made fin whale plates stronger and stiffer. Exposure to gasoline for 1.5 h or 14 days, crude oil for 8 days, or tar for 21 days resulted in loss of trace elements from baleen, and inconsistent changes in keratin organization. After tar exposure, fin whale baleen plates were stiffer and stronger. We presume that at sea, baleen would be relatively resistant to damage by spilled oil.