Temperature-Dependent Sex Determination in Tuatara
Author Information
Author(s): Mitchell Nicola J, Nelson Nicola J, Cree Alison, Pledger Shirley, Keall Susan N, Daugherty Charles H
Primary Institution: Victoria University of Wellington
Hypothesis
Does temperature influence the sex determination in tuatara species?
Conclusion
An FM pattern of temperature-dependent sex determination is evident in tuatara, which may be affected by global warming.
Supporting Evidence
- In Sphenodon guntheri, males were produced above a pivotal temperature of 21.6°C.
- In Sphenodon punctatus, males were produced above a pivotal temperature of 22.0°C.
- The thermosensitive period for sex determination occurs between 0.25 and 0.55 of embryonic development.
- Natural nests with higher temperatures during the thermosensitive period produced predominantly males.
Takeaway
The temperature at which tuatara eggs are kept can determine if they hatch as males or females, and warmer temperatures tend to produce more males.
Methodology
Eggs were incubated at constant temperatures ranging from 18 to 24°C to observe the resulting sex ratios.
Potential Biases
Potential biases may arise from the limited number of natural nests studied and the artificial incubation conditions.
Limitations
The study's findings may not be generalizable to all tuatara populations due to low genetic diversity and small sample sizes in some cases.
Participant Demographics
The study focused on two species of tuatara, Sphenodon guntheri and Sphenodon punctatus, from specific locations in New Zealand.
Statistical Information
P-Value
p < 0.001
Confidence Interval
± 0.16 for pivotal temperature
Statistical Significance
p < 0.001
Digital Object Identifier (DOI)
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