Extreme Physiological Plasticity in a Hibernating Basoendothermic Mammal, Tenrec ecaudatus

Authors

Michael D. Treat, University of Nevada, Las VegasFollow
Lori Scholer, University of Nevada, Las Vegas
Brandon Barrett, University of Nevada, Las Vegas
Artur Khachatryan, University of Nevada, Las Vegas
Austin J. McKenna, University of Nevada, Las VegasFollow
Tabitha Reyes, University of Nevada, Las Vegas
Alhan Rezazadeh, University of Nevada, Las Vegas
Charles F. Ronkon, University of Nevada, Las Vegas
Dan Samora, University of Nevada, Las Vegas
Jeremy F. Santamaria, University of Nevada, Las Vegas
Claudia Silva Rubio, University of Nevada, Las Vegas
Evan Sutherland, University of Nevada, Las Vegas
Jeffrey Richardson, Sable Systems International
John R. B. Lighton, Sable Systems International
Frank van Breukelen, University of Nevada, Las VegasFollow

Document Type

Article

Publication Date

10-18-2018

Publication Title

Journal of Experimental Biology

Volume

221

Issue

20

First page number:

1

Last page number:

9

Abstract

Physiological plasticity allows organisms to respond to diverse conditions. However, can being too plastic actually be detrimental? Malagasy common tenrecs, Tenrec ecaudatus, have many plesiomorphic traits and may represent a basal placental mammal. We established a laboratory population of T. ecaudatus and found extreme plasticity in thermoregulation and metabolism, a novel hibernation form, variable annual timing, and remarkable growth and reproductive biology. For instance, tenrec body temperature (Tb) may approximate ambient temperature to as low as 12°C even when tenrecs are fully active. Conversely, tenrecs can hibernate with Tb of 28°C. During the active season, oxygen consumption may vary 25-fold with little or no change in Tb. During the austral winter, tenrecs are consistently torpid but the depth of torpor may vary. A righting assay revealed that Tbcontributes to but does not dictate activity status. Homeostatic processes are not always linked, e.g. a hibernating tenrec experienced a ∼34% decrease in heart rate while maintaining constant body temperature and oxygen consumption rates. Tenrec growth rates vary but young may grow ∼40-fold in the 5 weeks until weaning and may possess indeterminate growth as adults. Despite all of this profound plasticity, tenrecs are surprisingly intolerant of extremes in ambient temperature (34°C). We contend that while plasticity may confer numerous energetic advantages in consistently moderate environments, environmental extremes may have limited the success and distribution of plastic basal mammals.

Keywords

Oxygen consumption; Thermoregulation; Variable body temperature

Disciplines

Animal Sciences

File Format

PDF

File Size

1.219 Kb

Language

English

Repository Citation

Treat, M. D., Scholer, L., Barrett, B., Khachatryan, A., McKenna, A. J., Reyes, T., Rezazadeh, A., Ronkon, C. F., Samora, D., Santamaria, J. F., Rubio, C. S., Sutherland, E., Richardson, J., Lighton, J. R., van Breukelen, F. (2018). Extreme Physiological Plasticity in a Hibernating Basoendothermic Mammal, Tenrec ecaudatus. Journal of Experimental Biology, 221(20), 1-9.
http://dx.doi.org/10.1242/jeb.185900