Abstract or Keywords
Global change is leading to increased prevalence of ectotherm diseases. Cryptosporidium
serpentis is a gastrointestinal, protozoal parasite that can cause varying degrees of morbidity and
mortality in snakes. The purpose of this study is to understand the innate immunity of eastern
indigo snakes (Drymarchon couperi) infected with C. serpentis. Body condition index,
heterophil: lymphocyte ratio, bactericidal ability, sheep red blood cell hemagglutination ability,
and plasma corticosterone levels were compared between C. serpentis positive (C+), negative
(C-), and recovered (Cr) individuals. Cr snakes had significantly higher BCI than C- and C+
snakes (ANOVA; F= 11.2 2,80, p<0.01), males had significantly higher bactericidal ability than
females (F= 1.24 2.94, p=0.0462), females had significantly higher corticosterone levels than males
(F=1.24, d.f=2,94, p=0.0462), bactericidal ability had a significant positive relationship with
heterophil: lymphocyte ratio (F=2.17, d.f.=2,71, p=0.033), and bactericidal ability had a
significant positive relationship with sheep red blood cell hemagglutination ability (F=2.17,
d.f.=2,71, p=0.033). These results suggest snakes that recover from C. serpentis may not have
any long-lasting negative effects in regard to their immune system or robustness. These results
also give insight into reptilian physiological ecology, supporting the hypothesis that meaningful
connections exist between different immunological traits.