Mechanism of tongue protraction in microhylid frogs

Jay J. Meyers, James C. O'Reilly, Jenna A. Monroy, Kiisa C. Nishikawa

Research output: Contribution to journalArticle

15 Scopus citations

Abstract

High-speed videography and muscle denervation experiments were used to elucidate the mechanism of tongue protraction in the microhylid frog Phrynomantis bifasciatus. Unlike most frogs, Phrynomantis has the ability to protract the tongue through a lateral arc of over 200° in the frontal plane. Thus, the tongue can be aimed side to side, independently of head and jaw movements. Denervation experiments demonstrate that the m. genioglossus complex controls lateral tongue aiming with a hydrostatic mechanism. After unilateral denervation of the m. genioglossus complex, the tongue can only be protracted towards the denervated (inactive) side and the range through which the tongue can be aimed is reduced by 75%. Histological sections of the tongue reveal a compartment of perpendicularly arranged muscle fibers, the m. genioglossus dorsoventralis. This compartment, in conjunction with the surrounding connective tissue, generates hydrostatic pressure that powers tongue movements in Phrynomantis. A survey of aiming abilities in 17 additional species of microhylid frogs, representing a total of 12 genera and six subfamilies, indicates that hydrostatic tongues are found throughout this family. Among frogs, this mechanism of tongue protraction was previously known only in Hemisus and may represent a synapomorphy of Hemisus and Microhylidae.

Original languageEnglish (US)
Pages (from-to)21-31
Number of pages11
JournalJournal of Experimental Biology
Volume207
Issue number1
DOIs
StatePublished - Jan 2004

Keywords

  • Feeding
  • Frog
  • M. genioglossus dorsoventralis
  • Microhylidae
  • Muscular hydrostat
  • Phrynomantis bifasciatus
  • Prey capture
  • Tongue protraction

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Physiology
  • Aquatic Science
  • Animal Science and Zoology
  • Molecular Biology
  • Insect Science

Fingerprint Dive into the research topics of 'Mechanism of tongue protraction in microhylid frogs'. Together they form a unique fingerprint.

  • Cite this