Fiber-type distribution of the perivertebral musculature in Ambystoma
Version of Record online: 25 AUG 2009
Copyright © 2009 Wiley-Liss, Inc.
Journal of Morphology
Volume 271, Issue 2, pages 200–214, February 2010
How to Cite
Schilling, N. and Deban, S. M. (2010), Fiber-type distribution of the perivertebral musculature in Ambystoma. J. Morphol., 271: 200–214. doi: 10.1002/jmor.10791
- Issue online: 7 JAN 2010
- Version of Record online: 25 AUG 2009
- Manuscript Accepted: 17 JUL 2009
- Manuscript Revised: 14 JUL 2009
- Manuscript Received: 1 MAY 2009
- Friedrich-Schiller-University Jena
- Berufsgenossenschaft Nahrungsmittel und Gaststätten Erfurt (Germany)
- enzyme histochemistry;
Many salamanders locomote in aquatic and terrestrial environments. During swimming, body propulsion is solely produced by the axial musculature generating lateral undulations of the trunk and tail. During terrestrial locomotion, the trunk is oscillated laterally in a standing wave, and body propulsion is achieved by concerted trunk and limb muscle action. The goal of this study was to increase our knowledge of the functional morphology of the tetrapod trunk. We investigated the muscle-fiber-type distribution and the anatomical cross-sectional area of all perivertebral muscles in Ambystoma tigrinum and A. maculatum. Muscle-fiber-type composition was determined in serial cross-sections based on m-ATPase activity. Five different body segments were investigated to test for cranio-caudal changes along the trunk. The overall fiber-type distribution was very similar between the species, but A. tigrinum had relatively larger muscles than A. maculatum, which may be related to its digging behavior. None of the perivertebral muscles possessed a homogeneous fiber-type composition. The M. interspinalis showed a distinct layered organization and may function to ensure the integrity of the spine (local stabilization). The M. dorsalis trunci exhibited the plesiomorphic pattern for notochordates in having a distinct superficial layer of red and intermediate fibers, which covered the central white fibers; therefore, it is suggested to function as a mobilizer and a stabilizer of the trunk, but, may also be involved in modulating body stiffness. Similarly, the M. subvertebralis showed clear regionalizations, implying functional subunits that can stabilize and mobilize the trunk as well as modulate of body stiffness. Cranio-caudally, neither the fiber-type composition nor the a-csa changed dramatically, possibly reflecting the need to perform well in both aquatic and terrestrial habitats. J. Morphol., 2010. © 2009 Wiley-Liss, Inc.