Characterisation of microsatellites for Litoria nannotis (Amphibia : Hylidae), an endangered waterfall frog endemic to the Australian Wet Tropics

Litoria nannotis is an endangered waterfall frog from the wet tropics region in north Queensland that has suffered significant population declines due to the emerging fungal disease known as chytridiomycosis. The species has two deeply divergent lineages, and we used 454 shotgun sequencing of DNA extracted from one individual of the northern lineage to identify and design PCR primers for 576 microsatellite loci. Thirty markers were tested for amplification success and variability in a population sample from each lineage. Of these, 17 were found to be polymorphic in the northern lineage and 10 loci were polymorphic in the southern lineage. Numbers of alleles per locus ranged from 2 to 14 (mean = 6.47, s.d. = 4.02) for the northern lineage (17 polymorphic loci), and from 2 to 8 (mean = 5.40, s.d. = 2.55) in the southern lineage (10 polymorphic loci). Levels of heterozygosity were high in both lineages (northern meanHE = 0.63, s.d. = 0.21, range = 0.27–0.89; southern mean HE = 0.57, s.d. = 0.25, range = 0.18–0.81). These loci will be useful in understanding the genetic variation and connectivity amongst populations of this species recovering from mass population declines due to disease

Seasonal, annual and decadal change in tadpole populations in tropical Australian streams

Abstract Declines due to fungal disease (chytridiomycosis) have affected many stream-dwelling frog species, especially in the tropics, leading to reduced abundance and diversity of their tadpoles. Studies in the Australian Wet Tropics have demonstrated that some frog species have declined or disappeared, while others have persisted. To assess the occurrence of stream-breeding frogs, we monitored tadpole populations of five frog species in Wet Tropics streams in the early 1990s (uplands, before chytridomycosis emergence), and in 2011-2013 (uplands and lowlands, after chytridiomycosis emergence), and investigated environmental factors that might influence tadpole abundance. Riffle-dwelling tadpoles of two frog species disappeared from the upland stream site during the 1990s, reflecting reported losses of adult populations. Tadpoles of one upland pool species initially declined but had recovered by 2011-2013. Samples from the lowlands in 2011 to 2013 indicated no similar loss. Chytridiomycosis was the likely cause of changes in tadpole abundances between the two survey periods, given its known occurrence and documented effects on adult frogs in these systems; however, we did not measure its prevalence in this study. Tadpole populations fluctuated seasonally, with abundances highest in spring and summer, reflecting the timing of frog reproduction. The most important biophysical influence on the assemblages that we measured was current velocity. Tadpole peak abundances suggest that they make a substantial contribution at the consumer level of food webs, and that their loss has altered food webs substantially in upland streams.</jats:p

Fresh Waters and Fish Diversity: Distribution, Protection and Disturbance in Tropical Australia

Background: Given the globally poor protection of fresh waters for their intrinsic ecological values, assessments are needed to determine how well fresh waters and supported fish species are incidentally protected within existing terrestrial protected-area networks, and to identify their vulnerability to human-induced disturbances. To date, gaps in data have severely constrained any attempt to explore the representation of fresh waters in tropical regions.\ud \ud Methodology and Results: We determined the distribution of fresh waters and fish diversity in the Wet Tropics of Queensland, Australia. We then used distribution data of fresh waters, fish species, human-induced disturbances, and the terrestrial protected-area network to assess the effectiveness of terrestrial protected areas for fresh waters and fish species. We also identified human-induced disturbances likely to influence the effectiveness of freshwater protection and evaluated the vulnerability of fresh waters to these disturbances within and outside protected areas. The representation of fresh waters and fish species in the protected areas of the Wet Tropics is poor: 83% of stream types defined by order, 75% of wetland types, and 89% of fish species have less than 20% of their total Wet Tropics length, area or distribution completely within IUCN category II protected areas. Numerous disturbances affect fresh waters both within and outside of protected areas despite the high level of protection afforded to terrestrial areas in the Wet Tropics (>60% of the region). High-order streams and associated wetlands are influenced by the greatest number of human-induced disturbances and are also the least protected. Thirty-two percent of stream length upstream of protected areas has at least one human-induced disturbance present.\ud \ud Conclusions/Significance: We demonstrate the need for greater consideration of explicit protection and off-reserve management for fresh waters and supported biodiversity by showing that, even in a region where terrestrial protection is high, it does not adequately capture fresh waters

Tick-Borne Pathogens in Ticks and Blood Samples Collected from Camels in Riyadh Province, Saudi Arabia

Background and Objective: Domestic animals, including camels, in Saudi Arabia suffer from various diseases, among which tick-borne infections are important because they reduce the productivity of these animals. However, knowledge of tick-borne pathogens in camels in Saudi Arabia is very limited, so the aims of this study were to quantify the abundance and distribution of tick species infesting camels from different districts of Riyadh province and use molecular tools to detect tick-borne pathogens in both the ticks and blood samples. Materials and Methods: A total of 218 ticks were collected from 116 camels from the 5 districts of Riyadh. The ticks and camel blood samples were analyzed for Borrelia, Babesia and Theileria pathogens using conventional and real-time PCR. Results: The results showed that five different tick species were identified. Majority of the ticks were Hyalomma dromedarii (70.6%), which were collected from camels in all 5 districts. This was followed by Hyalomma impeltatum species (25.2%), which was again found in all the districts. The other species found were Hyalomma anatolicum, Haemaphysalis sp. and Rhipicephalus turanicus. The only one H. dromedarii tick was positive for Theileria sp. DNA. Although the sample size and the area of tick collection were limited, the data suggest that the prevalence of pathogens in the Riyadh province, Saudi Arabia is relatively low. Conclusion: The study provides useful preliminary data to inform future full-scale country-wide surveys

Current Status and Natural History of the Critically Endangered Variable Harlequin Toad (Atelopus varius) in Costa Rica

The Variable Harlequin Toad (Atelopus varius) has suffered extensive declines in Panama and Costa Rica.Of 169 previously documented populations, only seven are known to survive. Herein we review the status of the survivingpopulations of this species in Costa Rica, describing the results of random visits to five of the seven survivingpopulations during the last six years, novel information on the natural history of three of these, and the results of amonitoring program of one continuous year on one of them. We identify three distinct morphs that might be the onlysurvivors of what once was a wide array of phenotypic color patterns

Drivers of Batrachochytrium dendrobatidis infection load, with evidence of infection tolerance in adult male toads (Bufo spinosus)

Chytridiomycosis is affecting hundreds of amphibian species worldwide, but while in tropical areas, adult individuals have been the focus of most investigations, the exact role played by infection intensity of breeding adults is not well understood in temperate areas. We conducted mark–recapture–capture surveys during spiny common toad breeding seasons from 2006 to 2018 at the site of the first recorded outbreak of chytridiomycosis in Europe, the Peñalara Massif (Sierra de Guadarrama National Park, central Spain), and collected infection samples and several variables related to the reproductive effort of male individuals. We used general linear mixed models to evaluate the contribution of study variables on the infection loads of adult male toads exhibited at their capturing date. We also analysed the differences on several male characteristics between the pond with the largest breeding population against the rest of the ponds. We found that the duration of time spent in the waterbody and the condition of the host predicted infection loads. Animals of good physical condition, that spent longer in water, have higher infection levels than individuals with the opposite set of traits. The pond supporting the largest breeding population housed smaller male toads and in poorer condition. Our results are consistent with a shift in reproductive strategy in response to infection and potentially a strategy of tolerance, rather than resistance to infection. These findings have applications for disease mitigation and theoretical implications related to the trade-offs made and the evolution of traits in response to the disease

Short-Term Exposure to Warm Microhabitats Could Explain Amphibian Persistence with Batrachochytrium dendrobatidis

Environmental conditions can alter the outcomes of symbiotic interactions. Many amphibian species have declined due to chytridiomycosis, caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd), but many others persist despite high Bd infection prevalence. This indicates that Bd's virulence is lower, or it may even be a commensal, in some hosts. In the Australian Wet Tropics, chytridiomycosis extirpated Litoria nannotis from high-elevation rain forests in the early 1990 s. Although the species is recolonizing many sites, no population has fully recovered. Litoria lorica disappeared from all known sites in the early 1990 s and was thought globally extinct, but a new population was discovered in 2008, in an upland dry forest habitat it shares with L. nannotis. All frogs of both species observed during three population censuses were apparently healthy, but most carried Bd. Frogs perch on sun-warmed rocks in dry forest streams, possibly keeping Bd infections below the lethal threshold attained in cooler rain forests. We tested whether short-term elevated temperatures can hamper Bd growth in vitro over one generation (four days). Simulating the temperatures available to frogs on strongly and moderately warmed rocks in dry forests, by incubating cultures at 33°C for one hour daily, reduced Bd growth below that of Bd held at 15°C constantly (representing rain forest habitats). Even small decreases in the exponential growth rate of Bd on hosts may contribute to the survival of frogs in dry forests