Intra-oropharyngeal food transport and swallowing in white-spotted bamboo sharks

Noraly M.M.E. van Meer*, Hannah I. Weller, Armita R. Manafzadeh, Elska B. Kaczmarek, Bradley Scott, Sander W.S. Gussekloo, Cheryl D. Wilga, Elizabeth L. Brainerd, Ariel L. Camp

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract


Despite the importance of intraoral food transport and swallowing, relatively few studies have examined the biomechanics of these behaviors in non-tetrapods, which lack a muscular tongue. Studies show that elasmobranch and teleost fishes generate water currents as a ‘hydrodynamic tongue’ that presumably transports food towards and into the esophagus. However, it remains largely unknown how specific musculoskeletal motions during transport correspond to food motion. Previous studies of white-spotted bamboo sharks (Chiloscyllium plagiosum) hypothesized that motions of the hyoid, branchial arches and pectoral girdle, generate caudal motion of the food through the long oropharynx of modern sharks. To test these hypotheses, we measured food and cartilage motion with XROMM during intra-oropharyngeal transport and swallowing (N=3 individuals, 2–3 trials per individual). After entering the mouth, food does not move smoothly toward the esophagus, but rather moves in distinct steps with relatively little retrograde motion. Caudal food motion coincides with hyoid elevation and a closed mouth, supporting earlier studies showing that hyoid motion contributes to intra-oropharyngeal food transport by creating caudally directed water currents. Little correspondence between pectoral girdle and food motion was found, indicating minimal contribution of pectoral girdle motion. Transport speed was fast as food entered the mouth, slower and step-wise through the pharyngeal region and then fast again as it entered the esophagus. The food's static periods in the step-wise motion and its high velocity during swallowing could not be explained by hyoid or girdle motion, suggesting these sharks may also use the branchial arches for intra-oropharyngeal transport and swallowing
Original languageEnglish
Article numberjeb201426
Number of pages9
JournalJournal of Experimental Biology
Volume2019
Issue number222
DOIs
Publication statusPublished - 22 Nov 2019

Fingerprint Dive into the research topics of 'Intra-oropharyngeal food transport and swallowing in white-spotted bamboo sharks'. Together they form a unique fingerprint.

Cite this