For some species, incubation temperature may have little or no effect on sex ratios Bull et al. Anatomy and physiology Amphibians: Photo by Kate Shaffer. Currently, there are studies which are being conducted to see if certain temperatures improve the health of males and if other temperatures the health of females. Finally, sexual differentiation in Soft-shelled Turtles Trionyx spiniferus was independent of incubation temperature. British Herpetological Society.
Recording and contextualizing the science of embryos, development, and reproduction.
Temperature-controlled turtle sex gene found
One interesting fact I came across while reading was that the temperature at which the eggs are incubated determines whether or not the turtle will be male or female. For American alligators, the temperature split occurs in the low thirties. Why should an animal benefit from letting the environment determine whether or not its offspring turns into male or female? He cited studies in which alligator eggs were incubated at 30 degrees centigrade 86 degrees Fahrenheit from the 7th through the 21st days after they were laid. This increase in aromatase enables individuals to develop into males or females depending on the temperatures experienced.
How temperature determines sex in alligators -- ScienceDaily
In lizards and turtles we can find both genetic-based and temperature-based sexual determination, while in tuataras and crocodilians sex is determined exclusively by temperature. Diversitat actual Amfibis: Warner and Shine used hormonal manipulations to produce males and females across a range of temperatures in a species with TSD. Harvey, Christine Janis, and John Heiser. On the same subject biology research. The proportion of embryos eliminating either one or two X-chromosomes determines the progeny sex-ratio.
Fujioka Y Survival, growth and sex ratios in gynogenetic diploid honmoroko. Valenzuela N, Lance V Temperature-dependent sex determination in vertebrates. The eastern bearded dragon Pogona barbata is an example of a reptile with GSD, but which is also affected by incubation temperature. The results, which found evidence of TSD in four out of five species, confirmed that some vertebrate species exhibit TSD. They did so to test the predictions of the Charnov-Bull model. Crews D Temperature, steroids and sex determination.