Incubation Temperature Influences Sex and Hatchling Size in the Neotropical Turtle Podocnemis unifilis

  title={Incubation Temperature Influences Sex and Hatchling Size in the Neotropical Turtle Podocnemis unifilis},
  author={Roselis Remor de Souza and Richard C Vogt},
  journal={Journal of Herpetology},
Geological control of Podocnemis expansa and Podocnemis unifilis nesting areas in Rio Javaés, Bananal Island, Brazil
The distribution of the nests of Podocnemis expansa (Amazon turtle) and Podocnemis unifilis (yellow-spotted side neck turtle) along the point bars of the Javaes River in Bananal Island, demonstratesExpand
Pivotal range and thermosensitive period of the pig-nosed turtle, Carettochelys insculpta (Testudines: Carettochelydidae), from northern Australia
This work determined two attributes for the pig-nosed turtle, Carettochelys insculpta Ramsay, 1886, in tropical Australia: the pivotal range in temperature that separates the male-producing domain from the female- producing domain, and the thermosensitive period during which the embryonic sex is influenced by temperature. Expand
Vulnerability of Giant South American Turtle (Podocnemis expansa) nesting habitat to climate-change-induced alterations to fluvial cycles
A change in seasonal flooding cycles in the Amazon may negatively impact nesting success of the Giant South American Turtle (Podocnemis expansa). Our aim was to devise a technique that could beExpand
Sedimentary characteristics and their effects on hatching success and incubation duration of Caretta caretta (Testudines: Cheloniidae) in Espirito Santo, Brazil
The beaches of Espirito Santo encompass the most important nesting sites of the loggerhead sea turtle, Caretta caretta (Linnaeus, 1758), in the South Atlantic Ocean. Previous research has shown that,Expand
Nesting ecology of Podocnemis expansa (Schweigger, 1812) and Podocnemis unifilis (Troschel, 1848) (Testudines, Podocnemididae) in the Javaés River, Brazil.
The results of this research show the importance of protecting areas with great geological diversity, wherein the features of the environment can affect the microenvironment of nests, with consequences on incubation duration and hatching success. Expand
On clutch size and hatching success of the South American turtles Podocnemis expansa (Schweigger, 1812) and P. unifilis Troschel, 1848 (Testudines, Podocnemididae).
  • P. Vanzolini
  • Biology, Medicine
  • Anais da Academia Brasileira de Ciencias
  • 2003
The outstanding fit of the clutch size regressions leads one to consider egg volume variability, which was found to be high in both species, in contradiction with current optimal egg size theory. Expand
Podocnemis expansa Turtles Hint to a Unifying Explanation for the Evolution of Temperature-Dependent Sex Determination in Long-Lived and Short-Lived Vertebrates
It is hypothesized that warmer-drier years overproduce females and correlate with optimal resource availability in the flood plains, benefitting daughters more than sons, whereas resources are scarcer during colder-rainier years that over produce males, whose fitness is less impacted by slower growth rates. Expand
Community based actions save Yellow-spotted river turtle (Podocnemis unifilis) eggs and hatchlings flooded by rapid river level rises
It is suggested that Yellow-spotted river turtle eggs and embryos are resistant to short-term submersion, which could help explain the widespread distribution of this species across highly seasonal Amazonian rivers. Expand
Natural nests incubated in two different soil types lead to an overall balanced sex ratio in Podocnemis unifilis hatchlings on the lower Purus River, Brazil
Temperature-dependent sex determination occurs in many species of turtles. Because substrates differ in their heat retention capacities, a relatively small change in ambient temperature can exertExpand
Sex is determined by XX/XY sex chromosomes in Australasian side-necked turtles (Testudines: Chelidae)
Despite morphological differences between sex chromosomes, it is concluded that male heterogamety was likely already present in the common ancestor of Chelodina , Emydura and Elseya in the Mesozoic period. Expand


Effect of Habitat on Survival of Eggs and Sex Ratio of Hatchlings of Caiman crocodilus yacare in the Pantanal, Brazil
Fifty percent of nesting occurred on floating grass mats, so the destruction of this habitat by introduced animals such as the water buffalo will adversely affect the productivity and hence long-term density of caimans in the Pantanal. Expand
Natural populations of species with TSD were found to have variable adult sex ratios, skewed towards one sex or the other, and these variations in sex ratio could sometimes be explained by nest site ecology. Expand
Environmental Sex Determination in Reptiles: Ecology, Evolution, and Experimental Design
Physiological investigations of TSD have clarified the roles of steroid hormones, various enzymes, and H-Y antigen in sexual differentiation, whereas molecular studies have identified several plausible candidates for sex-determining genes in species with TSD. Expand
Sex-determining potencies vary among female incubation temperatures in a turtle.
This work compared sex determining potencies of two all-female temperatures by incubating eggs first at a male-producing temperature and then shifting them to the warm temperatures, indicating that 32.5 degrees C has the greater female potency. Expand
Sexual differentiation and hatching success by painted turtles incubating in different thermal and hydric environments
The findings reaffirm the importance of the hydric environment to hatching success, duration of incubation, and size at hatching in painted turtles, but do not support earlier findings that moisture affects the pattern of sexual differentiation in this species. Expand
Nest temperatures in the pleurodiran turtle, Emydura macquarii
Nests may experience wide daily fluctuations in temperature and nest temperatures are higher later in the season than earlier, and incubation time in the field depends on which part of the season oviposition occurred and on the degree of shading of the nest. Expand
Temperature dependent sex determination in the green turtle (Chelonia mydas): effects on the sex ratio on a natural nesting beach
Temperatures of natural nests of green turtles, Chelonia mydas, determined the sex of hatchlings at Tortuguero, Costa Rica, and the primary sex ratio computed for the entire beach for the 1977 nesting season was 67:33 female: male. Expand
Sources of Heat for Nests of Paleosuchus trigonatus and a Review of Crocodilian Nest Temperatures
Investigations of the tropical- rainforest habitat of Paleosuchus trigonatus indicate that its nests are not warmed by the processes that have been suggested for nests of other species: insolation, rotting vegetation, and metabolic heat of embryos. Expand