José Fernando Aguilera González¹ | Claudio Azat Soto¹ | Alessandro Catenazzi² | Ignacio De la Riva³ | Patricia A. Burrowes⁴ | Tracie A. Seimon⁵ | John Cossel Jr.⁶ | Roberto Elías Piperis⁷ | Romina Ghirardi⁸

1. Sustainability Research Centre & PhD in Conservation Medicine Program, Life Sciences Faculty, Universidad Andres Bello, Santiago, Chile; 2. Department of Biological Sciences & Institute of Environment & Latin American and Caribbean Center, Florida International University, USA; 3. Department of Biodiversity and Evolutionary Biology, National Museum of Natural Sciences-CSIC, Madrid, Spain; 4. Department of Biology, University of Puerto Rico, San Juan, Puerto Rico; 5. Wildlife Conservation Society, Zoological Health Program, Bronx Zoo, Bronx, NY, USA; 6. Biology Department, Northwest Nazarene University, Nampa, Idaho, USA; 7. Faculty of Veterinary Medicine and Zootechnics, Peruvian University Cayetano Heredia Peru; 8. National Institute of Limnology (INALI, CONICET-UNL), National Council for Scientific and Technological Research. Santa Fe, Argentina.

Ponente: José Fernando Aguilera González, mvzferglez@gmail.com

Amphibian chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd), has been associated with the greatest loss of biodiversity due to a single pathogen. Globally, amphibians living at high altitudes and wet climates exhibit high Bd prevalence and chytridiomycosis-related mortalities. Among the groups experiencing the greatest population declines and extinctions due to Bd are Telmatobius spp., a group of 63 aquatic and highly threatened species, distributed across the central Andes of South America. To provide an evidence-based approach to assess the extent and consequences of Bd to Telmatobius, we conducted epidemiological analyses using Bd prevalence and Bd infection intensity data.  We analyzed quantitative real-time PCR data of 2,618 Telmatobius individuals sampled from 2000 to 2021. The information came from scientific literature (n=2,202) and a set of unpublished data (n=416) generated by the authors. Data included 18 species of Telmatobius, distributed in six ecoregions. Overall Bd prevalence was 49% (CI:47-51%), and was greater in tadpoles than adults (52%, CI:49-54% vs. 42%, CI:39-45%; x²=23.1, p<0.01). Also, the Central Andean Puna showed a higher Bd prevalence (61%, CI:57-65%) compared to other ecoregions (x²=291.08, df=5, p<0.01). Infection intensities ranged from 0 to 11,600 genomic equivalents (GE) in tadpoles, and from 0 to 101,861 GE in adults. Among infected frogs, 95% had low (0.01-999 GE), 4% moderate (1000–9,999), and less than 1% high Bd loads (≥10,000 GE). Between ecoregions, the Central Andean Wet Puna (583 [GE], CI:81.4-1,085) had the highest mean Bd infection intensity (Kruskal-Wallis x²=208.62, df=5, p<0.01). At species level, Telmatobius chusmisensis (1,895 [GE], CI:902-2,888) exhibited higher Bd loads, followed by T.culeus (632 [GE], CI:0-1,390) and T.marmoratus (587 [GE], CI:0-1,180). Our study is the first to assess the impacts of Bd in the family Telmatobidae, adding key information to guide strategies to mitigate the effects of Bd in this threatened taxa. Funding: Fondecyt Regular 1211587.