QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online February 20, 2004
Journal of Experimental Biology 207, 1183-1192 (2004)
Published by The Company of Biologists 2004
doi: 10.1242/jeb.00870

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kohlsdorf, T. Articles by Navas, C. A. Search for Related Content PubMed PubMed Citation Articles by Kohlsdorf, T. Articles by Navas, C. A. Social Bookmarking                         What's this?

Locomotor performance of closely related Tropidurus species: relationships with physiological parameters and ecological divergence

Tiana Kohlsdorf¹, Rob S. James², José E. Carvalho¹, Robbie S. Wilson³, Maeli Dal Pai-Silva⁴ and Carlos A. Navas^1,*

¹ Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, Travessa 14, No. 321, 05508-900, São Paulo, SP, Brazil
² School of Science and the Environment, Coventry University, James Starley Building, Priory Street, Coventry CV1 5FB, UK
³ Department of Zoology and Entomology, The University of Queensland, St Lucia, QLD 4072, Australia
⁴ Departamento de Morfologia, Instituto de Biociências, Universidade Estadual Paulista, 18618-000, Botucatu, SP, Brazil

^* Author for correspondence (e-mail: navas{at}usp.br)

Accepted 9 January 2004

Tropidurid lizards have colonized a variety of Brazilian open environments without remarkable morphological variation, despite ecological and structural differences among habitats used. This study focuses on two Tropidurus sister-species that, despite systematic proximity and similar morphology, exhibit great ecological divergence and a third ecologically generalist congeneric species providing an outgroup comparison. We quantified jumping capacity and sprint speed of each species on sand and rock to test whether ecological divergence was also accompanied by differences in locomotor performance. Relevant physiological traits possibly associated with locomotor performance – metabolic scopes and fiber type composition, power output and activity of the enzymes citrate synthase, pyruvate kinase and lactate dehydrogenase of the iliofibularis muscle – were also compared among the three Tropidurus species. We found that the two sister-species exhibited remarkable differences in jumping performance, while Tropidurus oreadicus, the more distantly related species, exhibited intermediate values. Tropidurus psamonastes, a species endemic to sand dunes, exhibited high absolute sprint speeds on sand, jumped rarely and possessed a high proportion of glycolytic fibers and low activity of citrate synthase. The sister-species Tropidurus itambere, endemic to rocky outcrops, performed a large number of jumps and achieved lower absolute sprint speed than T. psamonastes. This study provides evidence of rapid divergence of locomotor parameters between sister-species that use different substrates, which is only partially explained by variation in physiological parameters of the iliofibularis muscle.

Key words: locomotion, Tropidurus, muscle physiology, metabolism, enzyme activity, habitat divergence, evolution

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?