Current address: The University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
Morphological convergence during pregnancy among predator and nonpredator populations of the livebearing fish Brachyrhaphis rhabdophora (Teleostei: Poeciliidae)
Article first published online: 24 AUG 2011
© 2011 The Linnean Society of London
Biological Journal of the Linnean Society
Volume 104, Issue 2, pages 386–392, October 2011
How to Cite
WESNER, J. S., BILLMAN, E. J., MEIER, A. and BELK, M. C. (2011), Morphological convergence during pregnancy among predator and nonpredator populations of the livebearing fish Brachyrhaphis rhabdophora (Teleostei: Poeciliidae). Biological Journal of the Linnean Society, 104: 386–392. doi: 10.1111/j.1095-8312.2011.01715.x
- Issue published online: 14 SEP 2011
- Article first published online: 24 AUG 2011
- Received 22 February 2011; revised 22 April 2011; accepted for publication 22 April 2011
- geometric morphometrics;
- life history;
Predation can drive morphological divergence in prey populations, although examples of divergent selection are typically limited to nonreproductive individuals. In livebearing females, shape often changes drastically during pregnancy, reducing speed and mobility and enhancing susceptibility to predation. In the present study, we document morphological divergence among populations of nonreproductive female livebearing fish (Brachyrhaphis rhabdophora) in predator and nonpredator environments. We then test the hypothesis that shape differences among nonreproductive females are maintained among reproductive females between predator and nonpredator environments. Nonreproductive females in predator environments had larger caudal regions and more fusiform bodies than females in nonpredator environments; traits that are associated with burst speed in fish. Shape differences were maintained in reproductive females, although the magnitude of this difference declined relative to nonreproductive females, suggesting morphological convergence during pregnancy. Phenotypic change vector analysis revealed that females in predator environments became more similar to females in nonpredator environments in the transition from nonreproductive to reproductive. Furthermore, the level of reproductive allocation affected shape similarly between predator environments. These results suggest a life-history constraint on morphology, in which predator-driven morphological divergence among nonreproductive B. rhabdophora is not maintained at the same level during pregnancy. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104, 386–392.