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The biogeography of cave fungi and factors that influence community composition are poorly known. The movement of animals into caves from the outside environment is thought to be one factor that affects cave mycota. Islands often have different faunal assemblages from the mainland, and this may affect the fungal diversity of island caves. In 2014 we swabbed walls in three natural solution caves on Anticosti Island, Quebec, to determine the composition of cave fungal assemblages present relative to well-studied nearby mainland sites. At least one of these caves, Grotte à la Patate in Anticosti National Park, appears to support overwintering bats. Culture-dependent methods were used to establish pure cultures, and fungi were identified by a combination of morphology and genetic sequencing. A total of 54 fungal taxa were identified, with a mean of 7.4 ± 3.9 taxa per swab. The most common taxa isolated were Penicillium spp., Pseudogymnoascus pannorum sensu lato, P. roseus, Trichoderma sp., Cladosporium spp., Thysanophora spp., Mucor sp., and Trichosporon dulcitum. Pseudogymnoascus destructans (Pd), the causative agent of the fungal disease white-nose syndrome in bats, was not detected, and we conclude that Pd was not present in the three sampled caves as of summer 2014. Two of the caves did not appear to be suitable bat hibernacula based on microclimate, although diverse fungal assemblages were detected on the walls. Several other fungal taxa common to bat hibernacula on the mainland, in addition to Pd, were lacking from Anticosti Island caves. We suggest that fungal assemblages on Anticosti Island are influenced by the absence of non-volant cave-visiting mammals on the island, particularly porcupines (Erethizon dorsatum) and raccoons (Procyon lotor), both frequent cave associates elsewhere in Maritime Canada. [ABSTRACT FROM AUTHOR]

The introduction of the fungal pathogen Pseudogymnoascus destructans (Pd) to North America has stimulated research on the poorly known mycology of caves. It is possible that the introduction of Pd reduces the diversity of fungi associated with bats hibernating in caves. To test this hypothesis we examined the fungal assemblages associated with hibernating bats (Myotis spp.) pre- and post- white-nose syndrome (WNS) infection in eastern Canada using culture-dependent methods. We found the mean number of fungal taxa isolated from bats/ hibernaculum was not significantly different between pre-infection (29.6 ± 6.1SD) and postinfection with WNS (32.4 ± 4.3). Although the number of fungal taxa per bat was significantly higher on Myotis lucifugus vs. M. septentrionalis, evidence suggests that this is a reflection of environmental features of individual hibernacula, rather than any biological difference between bat species. The composition and number of the most common and widespread fungal taxa on hibernating Myotis spp. did not change with the introduction of Pd to hibernacula. We found no evidence to suggest that Pd interacts with other fungi on the external surface of bats in hibernacula, even among fungal species of the same genus. However, our data do suggest that environmental characteristics of individual caves can have a significant influence on the fungal assemblages cultured from hibernating bats at specific hibernacula. Following the mortality of thousands of WNS-infected Myotis spp. in one hibernacula, we found that those fungal taxa growing on dead bats were cultured with increased frequency from live bats. This suggests that fungal assemblages on live bats may be sensitive to sporadic introductions of new fungal substrates to hibernacula. [ABSTRACT FROM AUTHOR]

The tricolored bat (Perimyotis subflavus) is threatened by white-nose syndrome (WNS), a fungal disease caused by Pseudogymnoascus destructans (Pd) and was recently ranked as endangered under the Canadian Species-at-Risk Act. There have been few prior studies on the fungi associated with over-wintering bats. Such information is important in assessing overall fungal diversity within the cave habitat, in determining the ecological role that bats may play as dispersers of fungi, and in the identification of fungal species potentially antagonistic to Pd. We swabbed twenty-two P. subflavus overwintering in caves and mines in New Brunswick, Canada, in 2012 and 2013. This produced 408 isolates comprising 60 taxa in 49 fungal genera with an average of 10.2 ± 3.9SD fungal taxa recorded per bat. We found fungal assemblages on P. subflavus (post- WNS) very similar to those we cultured previously from Myotis spp. (pre-WNS) at the same sites. We suggest that the variation in fungal assemblages observed from site-to-site on hibernating P. subflavus is largely due to environmental and ecological characteristics of individual caves, rather than the presence of Pd or roosting habits. [ABSTRACT FROM AUTHOR]