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Article
Squeaking with a sliding joint: mechanics and motor control of sound production in palinurid lobsters
Journal of Experimental Biology (2002)
  • Sheila Patek, University of Massachusetts - Amherst
Abstract
The origin of arthropod sound-producing morphology typically involves modification of two translating body surfaces, such as the legs and thorax. In an unusual structural rearrangement, I show that one lineage of palinurid lobsters lost an antennal joint articulation, which transformed this joint from moving with one degree of freedom into a sliding joint with multiple degrees of freedom. With this sliding joint, `stick-and-slip' sounds are produced by rubbing the base of each antenna against the antennular plate. To understand the musculo-skeletal changes that occurred during the origin and evolutionary variation of this sound-producing mechanism, I examined joint morphology and antennal muscle anatomy across sound-producing and non-sound-producing palinurids. Plectrum movement and antennal muscle activity were measured in a sound-producing species, Panulirus argus. The promotor muscle pulls the plectrum over the file during sound-producing and non-sound-producing movements; a higher intensity of muscle activity is associated with sound production. The promotor muscle is larger and attaches more medially in sound-producing palinurids than in non-sound producers. In Panulirus argus, each shingle on the file has an additional ridge; in Palinurus elephas, the shingle surfaces are smooth. These differences in shingle surface features suggest variation in the stick-and-slip properties of the system. Translational motion permitted by the sliding joint is necessary for sound production; hence, the construction of a sliding joint is a key modification in the origin of this sound-producing mechanism.
Keywords
  • stridulation,
  • Palinuridae,
  • spiny lobster,
  • Panulirus argus,
  • Palinurus elephas,
  • joint,
  • biomechanics,
  • sound production,
  • bioacoustics,
  • stringed instrument
Disciplines
Publication Date
2002
Publisher Statement
Attribution-NonCommercial-ShareAlike CC BY-NC-SA
Citation Information
Sheila Patek. "Squeaking with a sliding joint: mechanics and motor control of sound production in palinurid lobsters" Journal of Experimental Biology Vol. 205 (2002)
Available at: http://works.bepress.com/sheila_patek/5/