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Slider Turtle (slider + turtle)

Distribution by Scientific Domains
Life Sciences57%

Selected Abstracts

QUANTITATIVE GENETICS OF PLASTRON SHAPE IN SLIDER TURTLES (TRACHEMYS SCRIPTA)

EVOLUTION, Issue 3 2006
Erin M. Myers
Abstract Shape variation is widespread in nature and embodies both a response to and a source for evolution and natural selection. To detect patterns of shape evolution, one must assess the quantitative genetic underpinnings of shape variation as well as the selective environment that the organisms have experienced. Here we used geometric morphometrics to assess variation in plastron shell shape in 1314 neonatal slider turtles (Trachemys scripta) from 162 clutches of laboratory-incubated eggs from two nesting areas. Multivariate analysis of variance indicated that nesting area has a limited role in describing plastron shape variation among clutches, whereas differences between individual clutches were highly significant, suggesting a prominent clutch effect. The covariation between plastron shape and several possible maternal effect variables (yolk hormone levels and egg dimensions) was assessed for a subset of clutches and found to be negligible. We subsequently employed several recently proposed methods for estimating heritability from shape variables, and generalized a univariate approach to accommodate unequal sample sizes. Univariate estimates of shape heritability based on Procrustes distances yielded large values for both nesting populations (h2, 0.86), and multivariate estimates of maximal additive heritability were also large for both nesting populations (h2max, 0.57). We also estimated the dominant trend in heritable shape change for each nesting population and found that the direction of shape evolution was not the same for the two sites. Therefore, although the magnitude of shape evolution was similar between nesting populations, the manner in which plastron shape is evolving is not. We conclude that the univariate approach for assessing quantitative genetic parameters from geometric morphometric data has limited utility, because it is unable to accurately describe how shape is evolving. [source]

Biological Materials: Mechanical Function of a Complex Three-Dimensional Suture Joining the Bony Elements in the Shell of the Red-Eared Slider Turtle (Adv. Mater.

ADVANCED MATERIALS, Issue 4 2009
4/2009)
The shell of a turtle is required to be a shield that is stiff at high loads, but must provide sufficient flexibility for respiration and locomotion at smaller loads. On p. 407, Peter Fratzl and co-workers show that these seemingly contradictory requirements are met by a self-locking material, whereby stiff bony elements are connected by a much softer suture with a complex three-dimensional shape. [source]

Mechanical Function of a Complex Three-Dimensional Suture Joining the Bony Elements in the Shell of the Red-Eared Slider Turtle

ADVANCED MATERIALS, Issue 4 2009
Stefanie Krauss
The shell of turtles is a shield which needs to be stiff at high loads but should provide sufficient flexibility for respiration and locomotion at smaller loads. We show that this seemingly contradictory requirement is met by a self-locking material, whereby stiff bony elements are connected by a much softer suture with a complex three-dimensional shape. [source]

From introduction to the establishment of alien species: bioclimatic differences between presence and reproduction localities in the slider turtle

DIVERSITY AND DISTRIBUTIONS, Issue 1 2009
Gentile Francesco Ficetola
ABSTRACT Aim, Understanding the factors determining the transition from introduction of aliens to the establishment of invasive populations is a critical issue of the study of biological invasions, and has key implications for management. Differences in fitness among areas of introduction can define the zones where aliens become invasive. The American slider turtle Trachemys scripta has been introduced worldwide, and has negative effects on freshwater communities, but only a subset of introduced populations breed successfully. We used species distribution models to assess the factors influencing the slider distribution in Italy, by analysing bioclimatic features that can cause the transition from presence of feral adults to breeding populations. We also evaluated whether climate change might increase the future suitability for reproduction. Location,, Central and Northern Italy. Methods,, The distribution of slider turtle was obtained from the literature, unpublished reports and field surveys. We used Maxent to build bioclimatic models. Results,, Reproductive populations are associated to a clear bioclimatic envelope with warmer climate, more solar radiation and higher precipitations than populations where reproduction is not observed. Several Mediterranean areas currently have climatic features suitable for sliders. Scenarios of climate change predict the expansion of these areas. In the near future (2020), the proportion of populations in areas suitable for reproduction will dramatically increase. Main conclusion,, Our study shows that bioclimatic differences can determine the areas where aliens become invaders. Management should be focused to these source areas. However, climate change can increase fitness in the future, and therefore the interactions between climate change and fitness can boost the invasiveness of this alien species. [source]

Pharmacokinetics of metronidazole in the red-eared slider turtle (Trachemys scripta elegans) after single intracoelomic injection

JOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 2 2007
C. INNIS
First page of article [source]

QUANTITATIVE GENETICS OF PLASTRON SHAPE IN SLIDER TURTLES (TRACHEMYS SCRIPTA)

EVOLUTION, Issue 3 2006
Erin M. Myers
Abstract Shape variation is widespread in nature and embodies both a response to and a source for evolution and natural selection. To detect patterns of shape evolution, one must assess the quantitative genetic underpinnings of shape variation as well as the selective environment that the organisms have experienced. Here we used geometric morphometrics to assess variation in plastron shell shape in 1314 neonatal slider turtles (Trachemys scripta) from 162 clutches of laboratory-incubated eggs from two nesting areas. Multivariate analysis of variance indicated that nesting area has a limited role in describing plastron shape variation among clutches, whereas differences between individual clutches were highly significant, suggesting a prominent clutch effect. The covariation between plastron shape and several possible maternal effect variables (yolk hormone levels and egg dimensions) was assessed for a subset of clutches and found to be negligible. We subsequently employed several recently proposed methods for estimating heritability from shape variables, and generalized a univariate approach to accommodate unequal sample sizes. Univariate estimates of shape heritability based on Procrustes distances yielded large values for both nesting populations (h2, 0.86), and multivariate estimates of maximal additive heritability were also large for both nesting populations (h2max, 0.57). We also estimated the dominant trend in heritable shape change for each nesting population and found that the direction of shape evolution was not the same for the two sites. Therefore, although the magnitude of shape evolution was similar between nesting populations, the manner in which plastron shape is evolving is not. We conclude that the univariate approach for assessing quantitative genetic parameters from geometric morphometric data has limited utility, because it is unable to accurately describe how shape is evolving. [source]