Meeting Abstract

P3.75  Thursday, Jan. 6  Physiological Variability in Neonatal Nine-banded Armadillo Clonal Siblings: Responses to Simulated Burrow Conditions During Development SPENCER, M.A.*; LENGYEL, M.S.; KNIGHT, F.; BAGATTO, B.; The University of Akron mas133@zips.uakron.edu

The interaction between the environment and an individual’s genetic template influence all physiological processes within an animal. The dynamics of this interaction will occupy researchers for decades. Clonal offspring, such as those in the nine-banded armadillo (Dasypus novemcinctus) provide a unique opportunity to essentially eliminate genotypic variation and focus on environmental causes of physiological variation. Furthermore, the physiological challenge of burrow conditions provides a view of sibling variation under acute stress. Typically, variation in offspring physiology is significantly less within litters than between litters, a phenomenon known as the “sibling effect”. Ten D. novemcinctus neonates were removed from their mother following birth and hand-reared in identical environments. The armadillo neonates, comprised of four litters, were exposed to acute hypoxia and hypercapnia, and O₂ consumption and CO₂ excretion was measured via flow through respirometry. Resting O₂ consumption and CO₂ excretion was also measured to determine basal metabolic rate (BMR). D. novemcinctus is known for having a low mass-specific BMR and low body temperature in comparison to other mammals. Armadillo neonates, similar to other mammalian neonates, follow a trend toward decreased mass-specific BMR as age increases. When exposed to acute stress, an increase in O₂ consumption and CO₂ excretion was seen in all armadillos, which is consistent with previous research of neonatal mammals exposed to hypoxia. Preliminary data show a difference BMR between litters, as well as a difference in BMR within litters exposed to both air and hypoxia/hypercapnia, confirming the presence of a sibling effect under acute stress.