Degree
Doctor of Biomedical and Veterinary Medical Sciences-Pathobiological Sciences (PVMPB)
Department
Veterinary Clinical Science Department
Document Type
Dissertation
Abstract
Amphibians represent the most threatened class of vertebrates, and 41% of these species are threatened with extinction due to habitat loss, emerging infectious diseases, and climate change. While in situ conservation addresses these issues in the medium- and long-term, ex situ conservation serves as a short-term solution to safeguard threatened species and establish assurance colonies. However, managing amphibians under ex situ settings remains challenging because there is a lack of knowledge across the diversity of amphibian species and limitations for fully replicating their natural habitat and nutrition under human care. Addressing these gaps through evidence-based research is essential to ensure the long-term survival of amphibians.
In this dissertation, the red-eyed tree frog (RETF, Agalychnis callidryas) and lemur tree frog (LTF, Agalychnis lemur), listed as least concern and critically endangered, respectively, were used as models to develop practical evidence-based data applicable for ex situ amphibian conservation. Nutritional strategies were evaluated through gut loading house crickets (Acheta domesticus) to deliver calcium and vitamin A, two major deficiencies in ex situ diets, with physiological outcomes assessed using micro computed tomography to measure bone density and liver lobectomies to quantify total retinol. Safe and reproducible diagnostic imaging was possible using a validated tricaine methane sulfonate sedation protocol, and the crickets were found to successfully transfer calcium to the LTF. Although similar protocols were followed for vitamin A, retinol concentrations did not differ between RETF on a vitamin A enriched and control diet. Studies evaluating the skin microbiome, an important component of the innate immune system, found differences between ex situ and in situ frogs that could be used to identify core microbes to treat common diseases (e.g., chytridiomycosis). Finally, ultraviolet B (UVB) radiation is thought to be beneficial and detrimental to amphibians. An ex situ study found UVB may result in pathologic ocular changes in RETF, suggesting its use ex situ requires more study before being implemented.
The targeted enhancements presented in the dissertation contribute to advancing evidence- based amphibian medicine and conservation and provide a foundation for improving the ex situ management and long-term survival of amphibians.
Date
2-27-2026
Recommended Citation
Aguilar, Maria G., "ENHANCING EX-SITU AMPHIBIAN CONSERVATION USING RED-EYED AND LEMUR TREE FROGS (AGALYCHNIS CALLIDRYAS AND AGALYCHNIS LEMUR) AS MODELS FOR IMPROVING NUTRITION, MICROBIOME HEALTH, AND HUSBANDRY" (2026). LSU Doctoral Dissertations. 7005.
https://repository.lsu.edu/gradschool_dissertations/7005
Committee Chair
Mitchell, Mark A.
LSU Acknowledgement
1
LSU Accessibility Acknowledgment
1