Faculty Advisor

Weiss, Stacey and Martin, Mark

Area of Study

Science and Mathematics

Publication Date

Summer 2021


Many oviparous species do not provide parental care for their offspring after laying their eggs. Sceloporus virgatus lay eggs in damp, dirt nests at the start of monsoon season. In the absence of egg-tending, pathogenic fungi can take advantage of the damp nest environments, feed off of the nutrients from the eggs, and ultimately kill the embryos. To prevent fungal diseases from growing on eggs, some oviparous species, like S. virgatus, transfer beneficial bacteria from their cloaca to their eggshells during oviposition. I conducted plate-based challenges using different cloacal bacteria from S. virgatus and environmental pathogenic fungi strains: Neocosmospora rubicola, Purpureocillium lilacinum, Aspergillus sp., and Fusarium sp. Each bacteria strain disrupted fungal growth to some degree, either through outcompeting the fungi for space and nutrients, or through inhibiting fungal growth altogether. These results indicate S. virgatus cloacal bacteria does impact the growth of pathogenic fungi, which may ultimately increase the hatch success and fitness of untended eggs.


General award


University of Puget Sound