Past Ex-Situ Research Projects:

Rita Caceres with tadpoles at FWZ

Rita Cáceres, graduate student University of Puerto Rico- Rio Piedras, weighing and photographing tadpoles at Fort Worth Zoo.


Cecilia Lnaghorne from MSU at FWZNatalie Calatayud from MSU at FWZ


Natalie Calatayud and Cecilia Langhorne, Mississippi State University, collecting eggs and analyzing toad semen at Fort Worth Zoo.


AZA believes that contemporary animal management, husbandry, veterinary care and conservation practices should be based in science, and that a commitment to scientific research, both basic and applied, is a trademark of the modern zoological park and aquarium. AZA-accredited-zoos and aquariums have the invaluable opportunity, and are expected to conduct or facilitate research both in in-situ and ex-situ settings to advance scientific knowledge of the animals in our care and enhance the conservation of wild populations.


Much can be learned from studying crested toads in captivity, which can be difficult to observe in the wild, and directly applied to their conservation. Although PRCT has been successfully maintained and bred in captivity for over three decades, nutrition and health-related problems continue to present significant challenges. Solutions found through research are required to improve the well-being of captive toads and sustain the breeding/reintroduction program long-term.


Previous research at AZA institutions:


Water temperature selection by tadpoles (Toronto Zoo)

Substrate temperature selection by toads (Toronto Zoo)

Evaluation using Bufo toxin as a trapping method for Rhinella marina tadpoles in the presence of P. lemur tadpoles (Fort Worth Zoo)



The effects of temperature on tadpole growth and development (Toronto Zoo)

The effects of salinity on tadpole growth and development of Peltophryne lemur and R. marina (Fort Worth Zoo)

The effects of density and temperature on P. lemur tadpole growth and development cohabitating with R. marina tadpoles  (Fort Worth Zoo)



The effects of varied diets on tadpole growth and development (Toronto Zoo)

The effects of various vitamin and mineral supplements on juvenile growth and development (Toronto Zoo)

The effects of varied diets on juvenile growth and development (Toronto Zoo)


Assisted Reproduction

LHRH/hCG trials for the production of semen in male toads (Toronto Zoo)

Evaluating LHRH/hCG efficacy and timing for PRCT reproduction (Fort Worth and Memphis Zoos)

Extraction and freezing of semen in adult toads (Omaha’s Henry Doorly Zoo and Memphis Zoo)


Health and Disease

Vitamin A deficiency studies in adult toads (Disney’s Animal Kingdom and Toronto Zoo)

Evaluating Brown Skin Syndrome in adult toads (Toronto, Fort Worth and North Carolina Zoos)

Determination of standard blood values in adult toads (North Carolina Zoo)

Determining if PRCT adults are susceptible or resilient to the amphibian fungus, Batrachochytrium dendrobatidis (North Carolina Zoo)