The scaling of tongue projection in the veiled chameleon, Chamaeleo calyptratus

Anthony Herrel, Chrystal L. Redding, J. Jay Meyers, Kiisa C Nishikawa

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Within a year of hatching, chameleons can grow by up to two orders of magnitude in body mass. Rapid growth of the feeding mechanism means that bones, muscles, and movements change as chameleons grow while needing to maintain function. A previous morphological study showed that the musculoskeletal components of the feeding apparatus grow with negative allometry relative to snout-vent length (SVL) in chameleons. Here, we investigate the scaling of prey capture kinematics and muscle physiological cross-sectional area in the veiled chameleon, Chamaeleo calyptratus. The chameleons used in this study varied in size from approximately 3 to 18. cm SVL (1-200. g). Feeding sequences of 12 chameleons of different sizes were filmed and the timing of movements and the displacements and velocities of the jaws, tongue, and the hyolingual apparatus were quantified. Our results show that most muscle cross-sectional areas as well as tongue and hyoid mass scaled with isometry relative to mandible length, yet with negative allometry relative to SVL. Durations of movement also scaled with negative allometry relative to SVL and mandible length. Distances and angles generally scaled as predicted under geometric similarity (slopes of 1 and 0, respectively), while velocities generally scaled with slopes greater than 0 relative to SVL and mandible length. These data indicate that the velocity of jaw and tongue movements is generally greater in adults compared to juveniles. The discrepancy between the scaling of cross-sectional areas versus movements suggests changes in the energy storage and release mechanisms implicated in tongue projection.

Original languageEnglish (US)
Pages (from-to)227-236
Number of pages10
JournalZoology
Volume117
Issue number4
DOIs
StatePublished - 2014

Fingerprint

Lizards
tongue
Tongue
Chamaeleonidae
Mandible
mandible (bone)
allometry
Jaw
Muscles
jaws
muscles
Biomechanical Phenomena
Chamaeleo
kinematics
Bone and Bones
hatching
bones
Growth
duration
energy

Keywords

  • Feeding apparatus
  • Feeding kinematics
  • Lizard
  • Prey capture

ASJC Scopus subject areas

  • Animal Science and Zoology
  • Medicine(all)

Cite this

The scaling of tongue projection in the veiled chameleon, Chamaeleo calyptratus. / Herrel, Anthony; Redding, Chrystal L.; Meyers, J. Jay; Nishikawa, Kiisa C.

In: Zoology, Vol. 117, No. 4, 2014, p. 227-236.

Research output: Contribution to journalArticle

Herrel, Anthony ; Redding, Chrystal L. ; Meyers, J. Jay ; Nishikawa, Kiisa C. / The scaling of tongue projection in the veiled chameleon, Chamaeleo calyptratus. In: Zoology. 2014 ; Vol. 117, No. 4. pp. 227-236.
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