Biology Projects

Dr. Carl Kloock

The Pirate Spider Mimetus hesperus preys on other species of spiders by invading their webs and using vibratory signals to lure the residents to within reach of their lightning-fast strike.  A previous REVSUP study comparing the abundance of Pirate Spiders across four habitats suggested that lower diversity spider communities foster larger populations of Pirate Spiders.  This summer’s REVSUP project will expand upon this previous research, sampling additional spider communities to determine if this relationship is consistent across larger landscapes in Kern County.  In addition, the project will expand our knowledge of the natural history of Pirate Spiders and contribute to the Guide to Common Spiders of Bakersfield. (Kloock 2011).

******Please be aware that Pirate Spiders are nocturnal organisms, as are their major prey.  For this reason, students working on this project will be expected to spend a significant portion of their time working at remote locations at night.******

Dr. Kathy Szick

Do bacteria found on the skin of the Pacific tree frog (Pseudacris regilla) play a role in protecting the frogs from fungal disease?

Chytridiomycosis, a disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), is causing a major decline in amphibian populations worldwide. Interestingly, some species will survive and co-exist in the presence of Bd. Our previous research reveals that bacteria associated with the skin of the North American Bull frog (Rana catesbeiana) and the California toad (Bufo boreas halophilus) secrete antifungal compounds, which may play a role in protecting their host. We have also observed that in the Southern San Joaquin Valley, the Pacific tree frog (Pseudacris regilla) is thriving despite the presence of this invasive pathogen. The success of the Pacific tree frog may be attributed to the commensal bacteria living on their skin. Given that for humans and other animals, skin acts as the first barrier of defense, we hypothesize that the bacteria found on the skin of the Pacific tree frog will inhibit the growth of Bd. Furthermore, we believe that the cutaneous bacteria may inhibit the growth of known amphibian and human pathogens. This project aims to identify each bacterial isolate that demonstrates antifungal properties by using DNA sequence analysis, and examining the diversity of cutaneous antifungal microbes. Antifungal bacterial isolates detected in this project may have the potential to widely impact global amphibian conservation and but more importantly their metabolites might be useful for novel chemotherapeutics to combat human diseases.