Predator mediated selection and the impact of developmental stage on viability in wood frog tadpoles (Rana sylvatica)

BMC Evolutionary Biology

Research Article

Shawn Kuchta¹  Ryan Calsbeek² 

[1] Department of Biological Sciences, Dartmouth College, 03755, Hanover, NH, USA;Department of Biological Sciences, Ohio University, 45701, Athens, OH, USA;Department of Biological Sciences, Dartmouth College, 03755, Hanover, NH, USA;National Evolutionary Synthesis Center, 27606, Durham, NC, USA;

关键词: Swimming Speed;    Tail Length;    Head Length;    Swimming Performance;    Wood Frog;   

DOI  :  10.1186/1471-2148-11-353

 received in 2011-08-10, accepted in 2011-12-07,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundComplex life histories require adaptation of a single organism for multiple ecological niches. Transitions between life stages, however, may expose individuals to an increased risk of mortality, as the process of metamorphosis typically includes developmental stages that function relatively poorly in both the pre- and post-metamorphic habitat. We studied predator-mediated selection on tadpoles of the wood frog, Rana sylvatica, to identify this hypothesized period of differential predation risk and estimate its ontogenetic onset. We reared tadpoles in replicated mesocosms in the presence of the larval odonate Anax junius, a known tadpole predator.ResultsThe probability of tadpole survival increased with increasing age and size, but declined steeply at the point in development where hind limbs began to erupt from the body wall. Selection gradient analyses indicate that natural selection favored tadpoles with short, deep tail fins. Tadpoles resorb their tails as they progress toward metamorphosis, which may have led to the observed decrease in survivorship. Path models revealed that selection acted directly on tail morphology, rather than through its indirect influence on swimming performance.ConclusionsThis is consistent with the hypothesis that tail morphology influences predation rates by reducing the probability a predator strikes the head or body.

【 授权许可】

CC BY   
© Calsbeek and Kuchta; licensee BioMed Central Ltd. 2011