Meeting Abstract

P1.23  Saturday, Jan. 4 15:30  THE EFFECTS OF SIZE HIERARCHY STATUS AND BEHAVIOR ON RANAVIRUS SUSCEPTIBILITY AND TRANSMISSION IN WOOD FROG Rana sylvatica LARVAE ARAUJO, A.M.*; WARNE, R.; Southern Illinois University alessandra@siu.edu

Across taxa, chronic stress generated by high levels of competition within size ranked hierarchies is associated with higher basal levels of glucorticoids in smaller individuals. Elevated GC levels, in turn, reinforce expression of phenotypes exhibiting increased metabolism, anorexia, compromised immune function, and submissive behavior. Within tadpole populations, variance in growth and development rates often results in well structured size hierarchies, with even greater size stratification occurring in populations exposed to limited resources. Size dependent physiology and behavior, therefore, should affect population infection dynamics by shaping individuals’ competitive success, exposure, transmission, and recovery rates. Here, we use Ranavirus, an emerging and directly transmitted pathogen in ectotherms, to test if size differences were associated with subsequent displays of behaviors that could alter disease susceptibility and transmission in Wood frog (Lithobates sylvaticus) larvae. We hypothesize larger individuals within hierarchies would display more aggressive behaviors with higher exposure and contact rates than their smaller counterparts, functioning as “super spreaders” of disease. We also hypothesized that smaller tadpoles would be more susceptible to infection because of consistently higher concentrations of glucocorticoids; immunosuppressive hormones under chronically elevated levels. The main goal of this study is to develop a social-neuroendocrine model through which stress physiology and individual response to imposed environmental conditions are integrated in order to better understand the role of size structured populations in epidemic disease outbreaks.