Alternative trait combinations and secondary resource partitioning in sexually selected color polymorphism
Article first published online: 31 MAY 2013
© 2013 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.
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Ecology and Evolution
Volume 3, Issue 7, pages 2038–2046, July 2013
How to Cite
Ecology and Evolution 2013; 3(7): 2038–2046
- Issue published online: 10 JUL 2013
- Article first published online: 31 MAY 2013
- Manuscript Accepted: 24 APR 2013
- Manuscript Revised: 20 APR 2013
- Manuscript Received: 18 MAR 2013
- Japan Society for the Promotion of Science
- Ecosystem Adaptability GCOE Program
- Tohoku University
- Body color;
- egg morphology;
- female polymorphism;
- phenotypic integration;
- resource partitioning
Resource partitioning within a species, trophic polymorphism is hypothesized to evolve by disruptive selection when intraspecific competition for certain resources is severe. However, in this study, we reported the secondary partitioning of oviposition resources without resource competition in the damselfly Ischnura senegalensis. In this species, females show color polymorphism that has been evolved as counteradaptation against sexual conflict. One of the female morphs is a blue-green (andromorph, male-like morph), whereas the other morph is brown (gynomorph). These female morphs showed alternative preferences for oviposition resources (plant tissues); andromorphs used fresh (greenish) plant tissues, whereas gynomorphs used decaying (brownish) plants tissues, suggesting that they chose oviposition resources on which they are more cryptic. In addition, the two-color morphs had different egg morphologies. Andromorphs have smaller and more elongated eggs, which seemed to adapt to hard substrates compared with those of gynomorphs. The resource partitioning in this species is achieved by morphological and behavioral differences between the color morphs that allow them to effectively exploit different resources. Resource partitioning in this system may be a by-product of phenotypic integration with body color that has been sexually selected, suggesting an overlooked mechanism of the evolution of resource partitioning. Finally, we discuss the evolutionary and ecological consequences of such resource partitioning.