Environmental DNA (eDNA) is becoming an indispensable tool in biodiversity monitoring, including the monitoring of invasive species and pathogens. Aquatic chytrid fungi Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal) are major threats to amphibians. However, the use of eDNA for detecting these pathogens has not yet become widespread, due to technological and economic obstacles. Using the enhanced eDNA approach (a simple and cheap sampling protocol) and the universally accepted qPCR assay, we confirmed the presence of Bsal and Bd in previously identified sites in Spain, including four sites that were new for Bsal. The new approach was successfully tested in laboratory conditions using manufactured gene fragments (gBlocks) of the targeted DNA sequence. A comparison of storage methods showed that samples kept in ethanol had the best DNA yield. Our results showed that the number of DNA copies in the Internal Transcribed Spacer region was 120 copies per Bsal cell. Eradication of emerging diseases requires quick and cost-effective solutions. We therefore performed cost-efficiency analyses of standard animal swabbing, a previous eDNA approach, and our own approach. The procedure presented here was evaluated as the most cost-efficient. Our findings will help to disseminate information about efforts to prevent the spread of chytrid fungi.
Batrachochytrium salamandrivorans (Bsal), a pathogenic fungus causing the fatal disease chytridiomycosis in amphibians, was likely introduced to Europe through the trade in pet salamanders from Asia and then escaped into wild populations. Among European countries, Spain has a large number of private breeders and keepers of pet salamanders, and cases of Bsal in wild and captive populations already have been confirmed there. However, surveillance for the pathogen in Spanish collections of amphibians is sparse. Therefore, assisted by private owners and breeders, we surveyed 10 amphibian collections and analysed a total of 317 samples for presence of Bsal. All of our analyses yielded negative results. However, this apparent lack of Bsal cases in captivity should not encourage relaxation of vigilance, quarantine efforts or good practices. Because amphibian collections represent highly dynamic environments (animals are coming in and out), the pathogen could easily be introduced into a collection by new individuals. Any case of Bsal infection in captive animals could lead to its further spread to wild populations of susceptible species, potentially decimating them, and thus should be prevented.
Behavioural consistency (i.e., personality) is a novel field of research in amphibians. Current published studies often address only one or two aspects of personality and therefore cannot assess more complex relationships and behavioural syndromes. This is the first study focusing on all relevant behavioural traits and their relationships in urodele amphibians. Based on the three trials of the experiment, we examined the consistency of activity (time spent moving), boldness (latency of the first movement and time spent escaping) and exploration (number of visited segments of testing arena) of 42 smooth newts ( Lissotriton vulgaris ). Individual consistency, calculated through the intraclass correlation coefficient (ICC), was low in newt activity (ICC = 0.192) and moderate in boldness (0.476) and exploration (0.403). Activity was moderately consistent for each trial (0.425), indicating a possible habituation, supported by a decrease of mean activity throughout the trials. Correlation of the behavioural traits studied suggests the presence of a behavioural syndrome, which potentially shaped the traits together. Our findings suggest the need for a complex approach to the study of amphibian personality and the need for standardized methodology, which would solve the current difficulties in comparing published results.
Surface mining is responsible for the large-scale destruction of affected landscapes. Simultaneously, the dumping of overburden soil on spoil banks during mining generates new landscapes, usually with heterogeneous topography. If spoil banks are not subsequently reclaimed technically (i.e., if the terrain is not leveled), considerable habitat diversity can thereby be established, consisting of numerous types of both terrestrial and water habitats. We compared the area and number of freshwater habitats between spoil banks (both technically unreclaimed and reclaimed) and the surrounding landscapes undisturbed by mining. The area of water habitats and especially their numbers per km2 were by far the greatest on unreclaimed spoil banks. Meanwhile, the quantity of water bodies on reclaimed spoil banks was about half that on non-mining landscapes. Great variety among the numerous water habitats, as indicated by their areas, depths, and proportions of aquatic vegetation on unreclaimed spoil banks, can contribute to regional landscape heterogeneity and water environment stability while providing conditions suitable for diverse taxa. The exceptional number of these water bodies can compensate for their loss in the surrounding landscape. We conclude that leaving some parts of spoil banks to spontaneous succession plays an irreplaceable role in the restoration of post-mining landscapes.