Distribution and dynamics of infection by the fungus Batrachochytrium dendrobatidis in anuran communities in the Atlantic Forest.

• Grant number: 24/17074-1
• Support Opportunities: Scholarships in Brazil - Master
• Start date: August 01, 2025
• End date: July 31, 2027
• Field of knowledge: Biological Sciences - Zoology - Applied Zoology
• Principal Investigator: Luis Felipe de Toledo Ramos Pereira
• Grantee: Letícia Lessio Cossolini
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Brazil is the country with the greatest diversity of amphibians in the world, mainly concentrated in the Atlantic Forest biome. Declines in amphibian populations in this biome are related to chytridiomycosis, a disease caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd). Despite the strong link between the decline of amphibians in the Atlantic Forest and chytridiomycosis, there are knowledge gaps about the dynamics of Bd in some areas, and studies investigating the fungus's lineages in the area are scarce. The Bd fungus has six different strains, the most virulent of which is Bd-GPL, widespread in the Atlantic Forest, and Bd-Hybrid, also found in the Atlantic Forest, which increases the risk of the disease in native animals. Both abiotic factors, such as latitudes and temperature, and biotic factors, such as the aquatic or terrestrial reproductive cycle of the hosts, play an important role in the dynamics of Bd infections. In the Atlantic Forest, the prevalence of Bd is associated with elevated environments. Sampling regions possibly affected by the chytrid fungus is of great importance for the maintenance and conservation efforts of endemic species. The aim of this study is to assess the prevalence of Bd in areas where knowledge is lacking, and to identify the strains present in each location: Serra da Bocaina National Park, Bananal Ecological Station, Serra do Mar State Park - Santa Virgínia Nucleus and Cunha Nucleus. We hypothesize that Bd is widely distributed in all the sites to be sampled in the Serra do Mar regions, that biotic and abiotic factors influence the occurrence of Bd in the communities, that there is more than one lineage of Bd in the localities, including the Bd-Hybrid lineage, and that the prevalence and load of Bd infection is different between species occupying different microhabitats. In order to achieve that, tadpoles and DNA samples from adult individuals will be collected, tested with qPCR for the presence of Bd and genotyped for the strain. Statistical analysis will also be carried out to analyze the influence of biotic, abiotic and latitudinal factors on the prevalence of Bd infection. Statistical models will be chosen depending on the characteristics of the information collected. (AU)