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Physiological variability in yearling alligators: clutch differences at rest and during activity.
B Bagatto1, D A Crossley, J Altimiras
1Department of Biology, University of Akron, Akron, OH 44325-3908, USA. bagatto@uakron.edu
Summary
Genetic factors significantly influence American alligator traits like size and physiology for at least one year, even in shared environments. Researchers must account for these genetic clutch effects in studies.
Area of Science:
- Herpetology
- Developmental Biology
- Physiological Ecology
Background:
- Phenotype results from genotype, environment, and their interaction.
- Early developmental clutch effects are known, but long-term persistence is less studied.
- Understanding genetic vs. environmental contributions is crucial for organismal development.
Purpose of the Study:
- To investigate the long-term persistence of clutch effects on American alligator morphology and physiology.
- To assess the relative contributions of genetic (clutch) and environmental factors over one year.
- To determine if clutch effects persist in a common environment.
Main Methods:
- Five clutches of American alligators were reared for one year under common environmental conditions.
- Morphological variables (size-related) and physiological characteristics were assessed.
- Statistical analyses were performed to identify significant clutch effects.
Main Results:
- Significant clutch effects were observed in all size-related morphological variables after one year.
- Lung and liver masses showed significant differences between clutches, even after accounting for total body mass.
- Clutch significantly influenced mean arterial pressure and acid-base balance during exercise, but not resting heart rate.
Conclusions:
- Genetic factors (clutch effects) demonstrably impact American alligator morphology and physiology for at least one year, despite a common environment.
- Environmental influences are significant, but genetic contributions remain measurable and important.
- Researchers should control for clutch effects in experimental designs involving American alligators.
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