Water‐borne and plasma corticosterone are not correlated in spotted salamanders

Authors

Alice R. Millikin
Sarah K. Woodley
Drew R. Davis, The University of Texas Rio Grande ValleyFollow
Ignacio T. Moore
James T. Anderson

Document Type

Article

Publication Date

11-18-2019

Abstract

Water‐borne hormone measurement is a noninvasive method suitable for amphibians of all sizes that are otherwise difficult to sample. For this method, containment‐water is assayed for hormones released by the animal. Originally developed in fish, the method has expanded to amphibians, but requires additional species‐specific validations. We wanted to determine physiological relevance of water‐borne corticosterone in spotted salamanders (Ambystoma maculatum) by comparing concentrations to those taken using established corticosterone sampling methods, such as plasma. Using a mixture of field and laboratory studies, we compared water‐borne corticosterone levels to other traditional methods of sampling corticosterone for spotted salamander larvae, metamorphs, and adults. Despite multiple attempts, and detecting differences between age groups, we found no correlations between water‐borne and plasma corticosterone levels in any age group. Water‐borne sampling measures a rate of release; whereas plasma is the concentration circulating in the blood. The unique units of measurement may inherently prevent correlations between the two. These two methods may also require different interpretations of the data and the physiological meaning. We also note caveats with the method, including how to account for differences in body size and life history stages. Collectively, our results illustrate the importance of careful validation of water‐borne hormone levels in each species in order to understand its physiological significance.

Comments

Original published version available at https://doi.org/10.1002/ece3.5831

Recommended Citation

Millikin AR, Woodley SK, Davis DR, Moore IT, Anderson JT. Water‐borne and plasma corticosterone are not correlated in spotted salamanders. Ecol Evol. 2019;9:13942–13953. doi.org/10.1002/ece3.5831

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Publication Title

Ecology and Evolution

DOI

10.1002/ece3.5831