Reproductive Allometry in the Common Map Turtle, Graptemys geographica

Ryan, Kath; Lindeman, Peter V.

doi:10.1674/0003-0031(2007)158[49:raitcm]2.0.co;2

Cited by 38 publications

(51 citation statements)

References 2 publications

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“…Optimal offspring (egg) size would be supported if clutch size is directly related to body size in an isometric function, and egg size shows no correlation with body size; whereas the morphological constraint hypothesis would be supported if clutch size and egg size are both related to female body size in a hypoallometric function. Ryan and Lindeman (2007) demonstrated support for the morphological constraint hypothesis in a population of Graptemys geographica, and also noted this pattern in the emydid turtles G. versa, Chrysemys picta, and Trachemys scripta.…”

Section: Introductionsupporting

confidence: 56%

“…All data were log transformed in order to reach normality and to satisfy the basic assumptions of the allometric approach (Stearns, 1992;Charnov, 1993;King, 2000). We follow Charnov (1993) in the use of simple regressions to test for isometry (null hypothesis) or hypo/hyperallometry; we also follow Ryan and Lindeman (2007) in expecting a slope of 3 for regressions with a volumetric measure like CS, CM, or EM on PL; and a slope of 1 when regressions involve the analysis of two linear measures (i.e., egg measurements on PL). A slope with a 95% confidence interval (CI) positioned below the expected value was considered as a significantly hypoallometric relationship; slopes with a 95% CI including the expected value were considered to be isometric, and slopes with 95% CI above the expected value were considered to be significantly hyperallometric.…”

Section: Data Collection and Analysismentioning

confidence: 99%

“…If a species has evolved an optimum offspring size, larger females may increase their fitness by simply producing more offspring (i.e. eggs) of an optimum size (Ryan and Lindeman, 2007). On the other hand, the morphological constraint hypothesis suggests that anatomical or physiological factors, such as the mother's pelvic aperture (Tucker et al, 1978;Congdon and Gibbons, 1987;Wilkinson et al, 2005), caudal gap (Clark et al, 2001), or endocrine-regulated egg size (Bowden et al, 2004), may constrain the balance between offspring size and offspring number.…”

Section: Introductionmentioning

confidence: 99%

“…On the other hand, the morphological constraint hypothesis suggests that anatomical or physiological factors, such as the mother's pelvic aperture (Tucker et al, 1978;Congdon and Gibbons, 1987;Wilkinson et al, 2005), caudal gap (Clark et al, 2001), or endocrine-regulated egg size (Bowden et al, 2004), may constrain the balance between offspring size and offspring number. In this case, small mothers produce smaller eggs than expected by their body size, and to increase their fitness, they should produce the greatest number of the largest eggs that they are physically capable of laying (Ryan and Lindeman, 2007). Evidence for optimal offspring size comes from a large number of nonavian reptilian species (Blueweiss et al, 1978;Congdon and Gibbons, 1987;Rohr, 1997;Radder and Shanbhag, 2004), whereas evidence for the morphological constraint hypothesis has been documented in long-lived reptiles (Ballinger, 1983;Bronikowski and Arnold, 1999;Gibbons, 1985, 1987;Wilbur and Morin, 1988;Vogt, 1990;Clark et al, 2001;Wilkinson et al, 2005;Ryan and Lindeman, 2007;Platt et al, 2008;Casas-Andreu et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

“…As Ryan and Lindeman (2007) have pointed out, the only logical way to test if turtle populations follow the optimal offspring size or the morphological constraint hypothesis is by using King's (2000) methodology. Optimal offspring (egg) size would be supported if clutch size is directly related to body size in an isometric function, and egg size shows no correlation with body size; whereas the morphological constraint hypothesis would be supported if clutch size and egg size are both related to female body size in a hypoallometric function.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Evidence for the Morphological Constraint Hypothesis and Optimal Offspring Size Theory in the Mexican Mud Turtle (Kinosternon integrum)

Macip-Ríos¹,

Brauer-Robleda

Casas-Andreu

et al. 2012

Zoological Science

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Optimal offspring size theory states that natural selection should balance reproductive output by optimizing between offspring size and offspring number. If a species has evolved an optimal offspring size, the fitness of larger females should be increased by simply producing more offspring of an optimum size. In contrast, when offspring size is not optimized, the morphological constraint hypothesis may apply, and in this case, maternal fitness is increased by producing the greatest number of the largest offspring that mothers are physically capable of producing. We used a log-log allometric regression approach on clutch size, egg size, and body size data to test the application of optimal offspring size theory and the morphological constraint hypothesis in the Mexican mud turtle (Kinosternon integrum) in southern Mexico. Our results indicate that this turtle seems to follow the morphological constraint hypothesis when all data are analyzed together, but when data are divided between small (< 140 mm plastron length) and large females (> 140 mm plastron length), optimal offspring (egg) size theory was supported only in large females, while the morphological constraint hypothesis was supported in small females. Our results thus indicate that K. integrum females may increase their fitness in two different, size-dependent ways as they grow from size at sexual maturity to maximum body size.

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Section: Introductionsupporting

confidence: 56%

Section: Data Collection and Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Evidence for the Morphological Constraint Hypothesis and Optimal Offspring Size Theory in the Mexican Mud Turtle (Kinosternon integrum)

Macip-Ríos¹,

Brauer-Robleda

Casas-Andreu

et al. 2012

Zoological Science

View full text Add to dashboard Cite

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The evolution of different maternal investment strategies in two closely related desert vertebrates

Ennen

Lovich

Averill‐Murray

et al. 2017

Ecology and Evolution

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We compared egg size phenotypes and tested several predictions from the optimal egg size (OES) and bet‐hedging theories in two North American desert‐dwelling sister tortoise taxa, Gopherus agassizii and G. morafkai, that inhabit different climate spaces: relatively unpredictable and more predictable climate spaces, respectively. Observed patterns in both species differed from the predictions of OES in several ways. Mean egg size increased with maternal body size in both species. Mean egg size was inversely related to clutch order in G. agassizii, a strategy more consistent with the within‐generation hypothesis arising out of bet‐hedging theory or a constraint in egg investment due to resource availability, and contrary to theories of density dependence, which posit that increasing hatchling competition from later season clutches should drive selection for larger eggs. We provide empirical evidence that one species, G. agassizii, employs a bet‐hedging strategy that is a combination of two different bet‐hedging hypotheses. Additionally, we found some evidence for G. morafkai employing a conservative bet‐hedging strategy. (e.g., lack of intra‐ and interclutch variation in egg size relative to body size). Our novel adaptive hypothesis suggests the possibility that natural selection favors smaller offspring in late‐season clutches because they experience a more benign environment or less energetically challenging environmental conditions (i.e., winter) than early clutch progeny, that emerge under harsher and more energetically challenging environmental conditions (i.e., summer). We also discuss alternative hypotheses of sexually antagonistic selection, which arise from the trade‐offs of son versus daughter production that might have different optima depending on clutch order and variation in temperature‐dependent sex determination (TSD) among clutches. Resolution of these hypotheses will require long‐term data on fitness of sons versus daughters as a function of incubation environment, data as yet unavailable for any species with TSD.

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An exploration of differences in the scaling of life history traits with body mass within reptiles and between amniotes

Hallmann

Griebeler

2018

Ecology and Evolution

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Allometric relationships linking species characteristics to body size or mass (scaling) are important in biology. However, studies on the scaling of life history traits in the reptiles (the nonavian Reptilia) are rather scarce, especially for the clades Crocodilia, Testudines, and Rhynchocephalia (single extant species, the tuatara). Previous studies on the scaling of reptilian life history traits indicated that they differ from those seen in the other amniotes (mammals and birds), but so far most comparative studies used small species samples and also not phylogenetically informed analyses. Here, we analyzed the scaling of nine life history traits with adult body mass for crocodiles (n = 22), squamates (n = 294), turtles (n = 52), and reptiles (n = 369). We used for the first time a phylogenetically informed approach for crocodiles, turtles, and the whole group of reptiles. We explored differences in scaling relationships between the reptilian clades Crocodilia, Squamata, and Testudines as well as differences between reptiles, mammals, and birds. Finally, we applied our scaling relationships, in order to gain new insights into the degree of the exceptionality of the tuatara's life history within reptiles. We observed for none of the life history traits studied any difference in their scaling with body mass between squamates, crocodiles, and turtles, except for clutch size and egg weight showing small differences between these groups. Compared to birds and mammals, scaling relationships of reptiles were similar for time‐related traits, but they differed for reproductive traits. The tuatara's life history is more similar to that of a similar‐sized turtle or crocodile than to a squamate.

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Reproductive Allometry in the Common Map Turtle, Graptemys geographica

Cited by 38 publications

References 2 publications

Evidence for the Morphological Constraint Hypothesis and Optimal Offspring Size Theory in the Mexican Mud Turtle (Kinosternon integrum)

Evidence for the Morphological Constraint Hypothesis and Optimal Offspring Size Theory in the Mexican Mud Turtle (Kinosternon integrum)

The evolution of different maternal investment strategies in two closely related desert vertebrates

An exploration of differences in the scaling of life history traits with body mass within reptiles and between amniotes

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