The turn of the sword: length increases male swimming costs in swordtails
- 7 August 2003
- journal article
- Published by The Royal Society in Proceedings Of The Royal Society B-Biological Sciences
- Vol. 270 (1524) , 1631-1636
- https://doi.org/10.1098/rspb.2003.2388
Abstract
Sexual selection via female mate choice can result in the evolution of elaborate male traits that incur substantial costs for males. Despite increased interest in how female mating preferences contribute to the evolution of male traits, few studies have directly quantified the locomotor costs of such traits. A sexually selected trait that could affect movement costs is the sword exhibited by male swordtail fishes: while longer swords may increase male mating success, they could negatively affect the hydrodynamic aspects of swimming activities. Here, we examine the energetic costs of the sword in Xiphophorus montezumae by experimentally manipulating sword length and measuring male aerobic metabolism during two types of activity, routine swimming and courtship swimming. Direct measurements of oxygen consumption indicate that males with longer swords expend more energy than males with shortened swords during both types of swimming. In addition, the sword increases the cost of male courtship. Thus, while sexual selection via female choice favours long swords, males with longer swords experience higher metabolic costs during swimming, suggesting that sexual and natural selection have opposing effects on sword evolution. This study demonstrates a hydrodynamic cost of a sexually selected trait. In addition, this study discriminates between the cost of a sexually selected trait used in courtship and other courtship costs.Keywords
This publication has 43 references indexed in Scilit:
- SEXY STREAMERS? THE ROLE OF NATURAL AND SEXUAL SELECTION IN THE EVOLUTION OF HIRUNDINE TAIL STREAMERSEvolution, 2001
- IMITATING THE INITIAL EVOLUTIONARY STAGE OF A TAIL ORNAMENTEvolution, 2000
- The effect of tail streamer length on aerodynamic performance in the barn swallowBehavioral Ecology, 2000
- The Energetics of Acoustic Signaling in Anurans and InsectsAmerican Zoologist, 1994
- Swallow tail streamer is a mechanical device for self-deflection of tail leading edge, enhancing aerodynamic efficiency and flight manoeuvrabilityProceedings Of The Royal Society B-Biological Sciences, 1994
- The effect of size on the kinematics and performance of angelfish (Pterophyllum eimekei) escape responsesCanadian Journal of Zoology, 1993
- Female preference for male sword length in the green swordtail, Xiphophorus helleri (Pisces: Poeciliidae)Animal Behaviour, 1990
- The Energetic Cost of Courtship and Aggression in a Plethodontid SalamanderEcology, 1983
- Locomotor Patterns in the Evolution of Actinopterygian FishesAmerican Zoologist, 1982
- Aquatic animal propulsion of high hydromechanical efficiencyJournal of Fluid Mechanics, 1970