Glucocorticoid and glycemic responses to immune challenge in a viviparous snake afflicted with an emerging mycosis.

Disease may be both a cause and a consequence of stress, and physiological responses to infectious disease may involve stress coping mechanisms that have important fitness consequences. For example, glucocorticoid and glycemic responses may affect host fitness by altering resource allocation and use in hosts, and these responses may be affected by competing stressors. To better understand the factors that affect host responses to infection, we challenged the immune system of field-acclimatized pygmy rattlesnakes, Sistrurus miliarius, with a sterile antigen, lipopolysaccharide (LPS), and measured the glucocorticoid and glycemic response in healthy non-reproductive snakes, snakes afflicted with an emerging mycosis (ophidiomycosis) and pregnant snakes.

Ophidiomycosis is associated with alterations in the acute glycemic and glucocorticoid stress response in a free-living snake species.

Emerging fungal pathogens are a direct threat to vertebrate biodiversity. Elucidating the mechanisms by which mycoses impact host fitness is an important step towards effective prediction and management of disease outcomes in populations. The vertebrate acute stress response is an adaptive mechanism that allows individuals to meet challenges to homeostasis and survival in dynamic environments.

The metabolic response to an immune challenge in a viviparous snake, .

Mounting an immune response may be energetically costly and require the diversion of resources away from other physiological processes. Yet, both the metabolic cost of immune responses and the factors that impact investment priorities remain poorly described in many vertebrate groups. For example, although viviparity has evolved many times in vertebrates, the relationship between immune function and pregnancy has been disproportionately studied in placental mammals.

Comparative skin permeability of neonatal and adult timber rattlesnakes (Crotalus horridus).

Skin permeability and lipid content were determined using shed epidermis of neonatal and adult timber rattlesnakes (Crotalus horridus) from the Coastal Plain Pine Barrens of New Jersey and from the Appalachian Mountains of northern Pennsylvania. Differences between populations due to habitat and within populations due to age were tested. Skin permeability was not found to differ according to locality (P>0.