Storage and recovery of elastic potential energy powers ballistic prey capture in toads

A. Kristopher Lappin, Jenna A. Monroy, Jason Q. Pilarski, Eric D. Zepnewski, David J Pierotti, Kiisa C Nishikawa

Research output: Contribution to journalArticle

63 Scopus citations


Ballistic tongue projection in toads is a remarkably fast and powerful movement. The goals of this study were to: (1) quantify in vivo power output and activity of the depressor mandibulae muscles that are responsible for ballistic mouth opening, which powers tongue projection; (2) quantify the elastic properties of the depressor mandibulae muscles and their series connective tissues using in situ muscle stimulation and force-lever studies; and (3) develop and test an elastic recoil model, based on the observed elastic properties of the depressor mandibulae muscles and series connective tissues, that accounts for displacement, velocity, acceleration and power output during ballistic mouth opening in toads. The results demonstrate that the depressor mandibulae muscles of toads are active for up to 250 ms prior to mouth opening. During this time, strains of up to 21.4% muscle resting length (ML) develop in the muscles and series connective tissues. At maximum isometric force, series connective tissues develop strains up to 14% ML, and the muscle itself develops strains up to 17.5% ML. When the mouth opens rapidly, the peak instantaneous power output of the depressor mandibulae muscles and series connective tissues can reach 9600 W kg-1. The results suggest that: (1) elastic recoil of muscle itself can contribute significantly to the power of ballistic movements; (2) strain in series elastic elements of the depressor mandibulae muscle is too large to be borne entirely by the cross bridges and the actin-myosin filament lattice; and (3) central nervous control of ballistic tongue projection in toads likely requires the specification of relatively few parameters.

Original languageEnglish (US)
Pages (from-to)2535-2553
Number of pages19
JournalJournal of Experimental Biology
Issue number13
StatePublished - Jul 2006



  • Contractile properties
  • Depressor mandibulae
  • Elastic properties
  • Elastic recoil model
  • Load clamp
  • Load dependence
  • Parallel elastic component
  • Power output
  • Series elastic component
  • Toad

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Agricultural and Biological Sciences (miscellaneous)

Cite this