Abstract
The chytrid fungal pathogens Batrachochytrium salamandrivorans
(Bsal) and B. dendrobatidis (Bd) are driving
amphibian extinctions and population declines worldwide. They are
thought to have originated in East/Southeast Asia, and hence Asia
remains crucial for understanding the ecology of these pathogens.
However, Bsal screening is relatively limited in this region,
particularly in hotspots where Bd lineage diversity is high. To
address this gap, we conducted an extensive survey across the Guangxi
region of Southern China, now considered a Bd hotspot. We
examined 1230 individuals from 38 amphibian species and 36 environmental
water bodies sampled during mostly the middle spring and summer months
of 2019-21. However, PCR testing revealed absence of Bsal in our
samples. A subsequent niche modeling analysis for Bsal suggested
that the bioclimatic conditions of much of the region may not be
conducive to Bsal. Although our findings show absence of
Bsal in the surveyed habitats, periodic monitoring in amphibians
is still needed, particularly across seasons. This is because
Bsal pathogenicity could increase at relatively lower
temperatures, and Bsal may be partitioning its niche with
Bd across seasons. Our results suggest that the climatic
conditions of the karstic Guangxi plains and perhaps competition from
other Bd lineages may suppress Bsal establishment in the
region. Our study provide interesting insights into Bsal niche
dynamics and the knowledge generated will facilitate the conservation
efforts in amphibian populations devastated by chytrid pathogens across
other regions of the world.