Batrachochytrium salamandrivorans

''Batrachochytrium salamandrivorans'' (''Bsal'') is a pathogenic chytrid fungus that infects amphibian species. Although salamanders and newts seem to be the most susceptible, some anuran species are also affected. ''Bsal'' has emerged recently and poses a major threat to species in Europe and North America.

It was described in 2013 based on a strain collected from skin tissue of fire salamanders '' Salamandra salamandra''. The pathogen, unidentified up to then, had devastated fire salamander populations in the Netherlands. Molecular phylogenetics confirmed it as related to the well known chytrid '' B. dendrobatidis''. Like this species, it causes chytridiomycosis, which is manifested in skin lesions and is lethal for the salamanders. Damage to the epidermal layer can be extensive and may result in osmoregulatory issues or sepsis.

Another study estimated that this species had diverged from ''B. dendrobatidis'' in the Late Cretaceous or early Paleogene. While initial susceptibility testing showed frogs and caecilians seemed to be resistant to ''Bsal'' infection, it was lethal to many European and some North American salamanders. East Asian salamanders were susceptible but able to tolerate infections. The fungus was also detected in a more-than-150-year-old museum specimen of the Japanese sword-tailed newt. This suggests it had originally emerged and co-evolved with salamanders in East Asia, forming its natural reservoir, and was introduced to Europe rather recently through the trade of species such as the fire belly newts as pets. The asian origin hypothesis for ''Bsal'' is supported by additional studies which have found ''Bsal'' in wild urodela populations in Asia and in animals of asian origin being transported via the pet trade. Since the pathogens initial discovery, it has been found in several additional areas across Europe in both wild and captive populations. One study was able to detect ''Bsal'' in 7 of 11 captive urodele collections.

The description of this pathogen and its aggressiveness raised concern in the scientific community and the public, fearing that it might be a rising threat to Western hemisphere salamanders. On January 12, 2016, the U.S. government issued a directive that prohibited the importation of salamanders in order to reduce the threat posed by ''B. salamandrivorans''.

Etymology

''Batrachochytrium'' is derived from the Greek words ''batrachos'', "frog", and ''chytra'', "earthen pot" (describing the structure that contains unreleased zoospores); ''salamandrivorans'' is from the Greek ''salamandra'', "salamander", and Latin ''vorans'', "eating", which refers to extensive skin destruction and rapid death in infected salamanders.

Susceptible Species

The most comprehensive ''Bsal'' species susceptibility performed to date has been by Martel et al 2014. Their experiments demonstrated ''Bsal'' susceptibility followed a phylogenetic trend with many Salamandridae species being lethally susceptible. Recent work has demonstrated that some lungless species, specifically those in the Spelerpini tribe might also be clinically susceptible to ''Bsal''

Tolerant

''Salamandrella keyserlingii''

''Siren intermedia''

Susceptible

'' Cynops cyanurus''

''Cynops pyrrhogaster''

'' Paramesotriton deloustali''

Lethal

'' Hydromantes strinatii''

''Salamandrina perspicillata''

'' Salamandra salamandra''

'' Pleurodeles waltl''

''Tylototriton wenxianensis''

''Notophthalmus viridescens''

''Taricha granulosa''

'' Euproctus platycephalus''

''Lissotriton italicus''

'' Ichthyosaura alpestris''

''Triturus cristatus''

'' Neurergus crocatus''

''Eurycea wilderae''

''Pseudotriton ruber''

Information Sources

More information on ''Bsal'' and other diseases impacting amphibian populations, including ''Batrachochytrium dendrobatidis'' and Ranavirus can be found at the Southeast Partners in Amphibian and Reptile Conservation disease task team web-page

References

External links

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{{Taxonbar, from=Q19826825

Chytridiomycota
Fungi described in 2013
Parasitic fungi