Dear Colleagues, I¹d like to bring your attention to a new publication in PLOS ONE:
Marshall, C.D., Marsh A., Wieskotten, S., Kot, B., Hanke W., Hanke, F., Dehndardt, G. 2014. Feeding kinematics, suction, and hydraulic jetting capabilities in harbor seals (Phoca vitulina). PloS ONE, Published January 24, 2014, DOI: 10.1371/journal.pone.0086710. A PDF of the article can be found at: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0086710; jsessionid=404BD518BF26B01C3A1F325957EE4B42 Abstract: The feeding kinematics, suction and hydraulic jetting capabilities of captive harbor seals (Phoca vitulina) were characterized during controlled feeding trials. Feeding trials were conducted using a feeding apparatus that allowed a choice between biting and suction, but also presented food that could be ingested only by suction. Subambient pressure exerted during suction feeding behaviors was directly measured using pressure transducers. The mean feeding cycle duration for suction-feeding events was significantly shorter (0.15±0.09 s; P<0.01) than biting feeding events (0.18±0.08 s). Subjects feeding in-water used both a suction and a biting feeding mode. Suction was the favored feeding mode (84% of all feeding events) compared to biting, but biting comprised 16% of feeding events. In addition, seals occasionally alternated suction with hydraulic jetting, or used hydraulic jetting independently, to remove fish from the apparatus. Suction and biting feeding modes were kinematically distinct regardless of feeding location (in-water vs. on-land). Suction was characterized by a significantly smaller gape (1.3±0.23 cm; P<0.001) and gape angle (12.9±2.02°), pursing of the rostral lips to form a circular aperture, and pursing of the lateral lips to occlude lateral gape. Biting was characterized by a large gape (3.63±0.21 cm) and gape angle (28.8±1.80°; P<0.001) and lip curling to expose teeth. The maximum subambient pressure recorded was 48.8 kPa. In addition, harbor seals were able to jet water at food items using suprambient pressure, also known as hydraulic jetting. The maximum hydraulic jetting force recorded was 53.9 kPa. Suction and hydraulic jetting where employed 90.5% and 9.5%, respectively, during underwater feeding events. Harbor seals displayed a wide repertoire of behaviorally flexible feeding strategies to ingest fish from the feeding apparatus. Such flexibility of feeding strategies and biomechanics likely forms the basis of their opportunistic, generalized feeding ecology and concomitant breadth of diet. Thank you, Christopher Marshall ----------------------------- Christopher D. Marshall, Ph.D.Associate Professor Department of Marine Biology, and Wildlife and Fisheries Sciences 200 Seawolf Parkway Building 3029, Room 253 Texas A&M University Galveston, Texas 77553 Phone: (409) 740-4884 Fax: (409) 740-5001 Email: marsh...@tamug.edu (please note the difference in the spelling of my last name) Website:www.tamug.edu/marshall -- Great things are not done by impulse, but by a series of small things brought together. - Vincent van Gogh _______________________________________________ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
