Reproductive traits and the level of parental investment in offspring varies between individuals and species. These are central issues in life history theory and evolutionary biology. Maternal body size plays an important role in reproduction, and we usually observe variable investment in offspring by females. Thus, optimal egg size may not be reached in some populations or species. In this study, we tested if reproductive traits differed between populations of D’Orbigny’s slider in a specific geographical area in Brazil. We evaluated the relationship between reproductive traits to maternal body size and clutch size to egg size to determine possible trade-offs across populations. At the population level, maternal body size and reproductive traits of D’Orbigny’s slider were different even in geographically nearby areas. Maternal body size had a positive effect on clutch size, but not on egg size, except in the Arroio Grande population. Nevertheless, we did not observe a negative correlation between clutch and egg size in any population. Although maternal body size had effects in the different populations explaining most of the variation of clutch size, variation in egg size may be the result of decreased survival chances in unpredictable environments and possibly morphological constraints. The trade-off between egg size and number was not observed and this could be expected if resource availability and reproductive allocation by females vary greatly among individuals.
BagerA. (2003): Aspectos da biologia e ecologia da tartaruga tigre d’água, Trachemys dorbignyi (Testudines, Emydidae) no extremo sul do Estado do Rio Grande do Sul, Brasil. Ph.D. Thesis, Universidade Federal do Rio Grande do Sul.
Estimation of core terrestrial habitats for freshwater turtles in southern Brazil based on nesting areas.
CongdonJ.D.DunhamA.E.van Loben SelsR.C. (1994):
Demographics of common snapping turtles (Chelydra serpentina): implications for conservation and management of long-lived organisms.
The evolution of different maternal investment strategies in two closely related desert vertebrates.
Relationships of maternal body size and morphology with egg and clutch size in the diamondback terrapin, Malaclemys terrapin (Testudines: Emydidae).
Biol. J. Linn. Soc.117:
Optimal egg size in a suboptimal environment: reproductive ecology of female Sonora mud turtles (Kinosternon sonoriense) in central Arizona, USA.
Not putting all their eggs in one basket: bet-hedging despite extraordinary annual reproductive output of desert tortoises.
Biol. J. Linn. Soc.115:
Evidence for the morphological constraint hypothesis and optimal offspring size theory in the Mexican mud turtle (Kinosternon integrum).
NaimiM.ZnariM.LovichJ.E.FeddadiY.Ait BaamraneM.A. (2012):
Clutch and egg allometry of the turtle Mauremys leprosa (Chelonia: Geoemydidae) from a polluted peri-urban river in west-central Morocco.
Life history variation among geographically close populations of the toad-headed lizard (Phrynocephalus przewalskii): exploring environmental and physiological associations.