Post-epizootic salamander persistence in a disease-free refugium suggests poor dispersal ability of Batrachochytrium salamandrivorans

• Published in: Scientific reports Vol. 8; no. 1; pp. 3800 - 8
• Main Authors: Spitzen - van der Sluijs, Annemarieke, Stegen, Gwij, Bogaerts, Sergé, Canessa, Stefano, Steinfartz, Sebastian, Janssen, Nico, Bosman, Wilbert, Pasmans, Frank, Martel, An
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 28-02-2018; Nature Publishing Group
• Subjects: 38/23; 38/77; 631/158/1469; 631/158/672; 631/601/2721; Barriers; Batrachochytrium; Dispersal; Fungi; Gene flow; Habitat fragmentation; Humanities and Social Sciences; multidisciplinary; Reptiles & amphibians; Salamandra salamandra; Science; Science (multidisciplinary); Subpopulations
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-018-22225-9

Lack of disease spill-over between adjacent populations has been associated with habitat fragmentation and the absence of population connectivity. We here present a case which describes the absence of the spill-over of the chytrid fungus
Batrachochytrium salamandrivorans
(Bsal) between two connected subpopulations of fire salamanders (
Salamandra salamandra
). Based on neutrally evolving microsatellite loci, both subpopulations were shown to form a single genetic cluster, suggesting a shared origin and/or recent gene flow. Alpine newts (
Ichthyosaura alpestris
) and fire salamanders were found in the landscape matrix between the two sites, which are also connected by a stream and separated by no obvious physical barriers. Performing a laboratory trial using alpine newts, we confirmed that Bsal is unable to disperse autonomously. Vector-mediated dispersal may have been impeded by a combination of sub-optimal connectivity, limited dispersal ability of infected hosts and a lack of suitable dispersers following the rapid, Bsal-driven collapse of susceptible hosts at the source site. Although the exact cause remains unclear, the aggregate evidence suggests that Bsal may be a poorer disperser than previously hypothesized. The lack of Bsal dispersal between neighbouring salamander populations opens perspectives for disease management and stresses the necessity of implementing biosecurity measures preventing human-mediated spread.