Literaturdatenbank
Literaturdatenbank |
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Delmas, V., Baudry, E., Girondot, M., & Prévot-Julliard, A.-C. (2007). The righting response as a fitness index in freshwater turtles. Biological Journal of the Linnean Society, 91(1), 99–109.
Added by: Admin (01 Aug 2010 18:21:52 UTC) |
| Resource type: Journal Article DOI: 10.1111/j.1095-8312.2007.00780 BibTeX citation key: Delmas2007 View all bibliographic details  |
Categories: General Keywords: Emydidae, Schildkröten = turtles + tortoises, Trachemys, Trachemys scripta, Zeitigung = incubation Creators: Baudry, Delmas, Girondot, Prévot-Julliard Collection: Biological Journal of the Linnean Society |
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| Abstract |
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Theoretical evolutionary ecology assumes the existence of fitness variability in natural populations. As realistic measures of fitness are usually difficult to perform directly, integrating fitness indices are proposed in all taxa. In sauropsids, locomotor performances have been proposed as a good integrating index of fitness in natural populations. Concerning aquatic turtles, a performance trait that may be important for the survival of juveniles is the righting response of individuals when they are placed on their carapace. In the present study, we examined the righting response in juveniles of the red-eared slider turtle, Trachemys scripta elegans. We tested two different measures of the righting response for 170 juveniles from constant incubation temperature and for 86 juveniles from three sinusoidal fluctuating incubation temperatures that are considered as more representative of natural conditions in the nest. We compared the effects of offspring sex, maternal identity, juvenile growth rate, and juvenile survival (i.e. individual characteristics), as well as the nutritional status of juveniles (i.e. experimental conditions), on the two different measures of righting response and for each thermal incubation treatments of the eggs (i.e. experimental treatments). We observed that the effects of the individual characteristics were markedly different between the two measures of the righting response and between experimental treatments. These results highlight the importance of the choice of the measure and of the experimental conditions and treatments in the study of a phenotypic trait. Results obtained for only one performance measure under constant laboratory conditions must therefore be extrapolated to the field with caution. Our results also show that the righting response presents individual variability that is probably heritable and is indirectly correlated with survival. These findings support the validity of the righting response as a good candidate for a fitness index in aquatic turtles.
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