Amphibian Species Research Articles

A synoptic review of the Amphibians of Iran: bibliography, taxonomy, synonymy, distribution, conservation status, and identification key to the eggs, larvae, and adults.

This study provides an illustrated account, a comprehensive update of the systematics, and a bibliography of the 15 species of anurans in five families, eight genera; and of the six species of urodeles in two families, four genera in Iran. Bufonidae, with eight species, is the most diverse family; Salamandridae has five species and Ranidae has four species. This study also presents updated identification keys for the eggs, larvae, and metamorphosed amphibians of Iran. We designated specimen NMW 19855.1 as neotype of Pelophylax persicus (Schneider, 1799) comb. nov.. Along with distribution maps obtained from all the reliable localities and museum specimens known at this time, the modelled habitat of species, and for the first time, the National Red List of amphibians based on the IUCN red list categories and criteria. Based on our evaluation we propose to categorize Bufo eichwaldi, Paradactylodon persicus, Neurergus derjugini, and N. kaiseri as Vulnerable at National Red List, and to move Bufotes (Calliopersa) luristanicus, B. (C.) surdus, Firouzophrynus olivaceus, and Rana pseudodalmatina from the category of Least Concern (LC) to Near Threatened (NT). The National Red List of amphibians that we propose has significant implications for endangered species management and conservation. Forty-one percent of amphibian species in Iran are endemic to the country, and more than forty percent of the Iranian amphibians are at risk of extinction. Zagros Mountain forest and Hyrcaniain forests have more than 80% (i.e. 18 species) of the diversity of Iranian amphibians. A considerable amount of scientific literature published on Iranian amphibians in Persian language is not easily accessible to researchers outside Iran. This monograph attempts to remedy the situation and provides broader access to international herpetology. We recognize that taxonomy is always in a state of flux, and the names and synonymies used here reflect our current view.

MHC architecture in amphibians - ancestral reconstruction, gene rearrangements and duplication patterns.

The hypervariable major histocompatibility complex (MHC) is a crucial component of vertebrate adaptive immunity, but large-scale studies on MHC macroevolution in non-model vertebrates have long been constrained by methodological limitations. Here, we used rapidly accumulating genomic data to reconstruct macroevolution of the MHC region in amphibians. We retrieved contigs containing the MHC region from genome assemblies of 32 amphibian species and examined major structural rearrangements, duplication patterns and gene structure across the amphibian phylogeny. Based on the few available caecilian and urodele genomes we showed that the structure of ancestral MHC region in amphibians was probably relatively simple and compact, with a close physical linkage between MHC-I and MHC-II regions. This ancestral MHC architecture was generally conserved in anurans, although the evolution of class I subregion proceeded towards more extensive duplication and rapid expansion of gene copy number, providing evidence for dynamic evolutionary trajectories. Although in anurans we recorded tandems of duplicated MHC-I genes outside the core subregion, our phylogenetic analyses of MHC-I sequences provided little support for an expansion of nonclassical MHC-Ib genes across amphibian families. Finally, we found that intronic regions of amphibian classical MHC genes were much longer when compared to other tetrapod lineages (birds and mammals), which could partly be driven by the expansion of genome size. Our study reveals novel evolutionary patterns of the MHC region in amphibians and provides a comprehensive framework for further studies on the MHC macroevolution across vertebrates.

Environmental Factors Affecting Amphibian Communities in River Basins of the Southern Apennines

The study of the environmental features affecting amphibian communities is a priority task for addressing effective conservation initiatives. In the southern edge of the Apennines (Sila Massif, Calabria Region, Italy), we surveyed the distribution of amphibians in lotic freshwater habitats (eight rivers, 17 sampling stations, 87 transects) and recorded nine environmental variables, including the occurrence of potential predators (fish and Eurasian otter Lutra lutra), potentially affecting the distribution and breeding success of amphibian species. A total of seven amphibian species was recorded (75.9% of transects). Fish occurred in all rivers while the otter was found in four rivers (Amato, Lese, Neto, and Savuto). Illuminance and bank heterogeneity were the main factors affecting amphibian reproduction, while neither otter nor fish presence showed significant effects on the amphibian community. Overall, habitat complexity and coevolution history seemed to shape the distribution of amphibians and their breeding sites, while the ongoing recolonization of the study area by the otter is expected to have a negligible impact on the richness of the amphibian community.

Life in plastic, it's not fantastic: Sublethal effects of polyethylene microplastics ingestion throughout amphibian metamorphosis

Microplastics (MP) are an abundant, long-lasting, and widespread type of environmental pollution that is of increasing concern as it might pose a serious threat to ecosystems and species. However, these threats are still largely unknown for amphibians. Here, we used the African clawed frog (Xenopus laevis) as a model species to investigate whether polyethylene MP ingestion affects amphibian growth and development and leads to metabolic changes across two consecutive life stages (larvae and juveniles). Furthermore, we examined whether MP effects were more pronounced at higher rearing temperatures. Larval growth, development, and body condition were recorded, and standard metabolic rate (SMR) and levels of stress hormone (corticosterone, CORT) were measured. We determined variation in size, morphology, and hepatosomatic index in juveniles to identify any potential consequences of MP ingestion across metamorphosis. In both life stages, MP accumulation in the body was assessed. MP ingestion was found to result in sublethal effects on larval growth, development, and metabolism, to lead to allometric carry-over effects on juvenile morphology, and to accumulate in the specimens at both life stages. In larvae, SMR and developmental rate increased in response to MP ingestion; there additionally was a significant interaction of MP ingestion and temperature on development. CORT levels were higher in larvae that ingested MP, except at higher temperature. In juveniles, body was wider, and extremities were longer in animals exposed to MP during the larval stage; a high rearing temperature in combination with MP ingestion counteracted this effect. Our results provide first insights into the effects of MP on amphibians throughout metamorphosis and demonstrate that juvenile amphibians may act as a pathway for MP from freshwater to terrestrial environments. To allow for generalizations across amphibian species, future experiments need to consider the field prevalence and abundance of different MP in amphibians at various life stages.

Hematologic parameters and the effect of hemoparasites of wild anurans in Northern Sinaloa, Mexico.

Few hematologic profiles for free-ranging amphibians are available. Hematologic evaluation is a useful tool for determining the health of amphibian populations and providing further knowledge for conservation actions. Hematologic variables and the presence and effect of hemoparasites in anuran species were evaluated in Northern Sinaloa, Mexico. Blood samples were collected from wild anurans of eight species to perform blood cell counts, leukocyte differential counts, and serum protein concentrations using manual methods and refractometry. In addition, morphologic identification and quantification of the hemoparasites were performed on blood smears. Differences were observed by sex, age, and season for the hematologic values of Incilius alvarius (n = 23), Incilius mazatlanensis (n = 46), Rhinella horribilis (n = 64), Leptodactylus melanonotus (n = 46), Lithobates forreri (n = 135), Lithobates catesbeianus (n = 20), Smilisca fodiens (n = 42), and Scaphiopus couchii (n = 7). Intra- and extra-erythrocytic hemoparasites were found in 56.2% of amphibian hosts; the hemoparasite infection of R. horribilis and L. melanonotus was higher in the dry season, showing increases in erythroplastids and monocytes. For L. forreri, males were more infected than females, and increases in leukocytes were associated with infections of different types of hemoparasites species. Hematologic values, hemoparasite prevalence, and the response to hemoparasite infection vary among amphibian species, sex, and age, as well as on season and hemoparasite type. This highlights the importance of hematologic evaluations in wild amphibian populations to determine the subclinical effects of hemoparasite infections.

Drought, fire, and rainforest endemics: A case study of two threatened frogs impacted by Australia's "Black Summer".

Deepening droughts and unprecedented wildfires are at the leading edge of climate change. Such events pose an emerging threat to species maladapted to these perturbations, with the potential for steeper declines than may be inferred from the gradual erosion of their climatic niche. This study focused on two species of amphibians-Philoria kundagungan and Philoria richmondensis (Limnodynastidae)-from the Gondwanan rainforests of eastern Australia that were extensively affected by the "Black Summer" megafires of 2019/2020 and the severe drought associated with them. We sought to assess the impact of these perturbations by quantifying the extent of habitat affected by fire, assessing patterns of occurrence and abundance of calling males post-fire, and comparing post-fire occurrence and abundance with that observed pre-fire. Some 30% of potentially suitable habitat for P. kundagungan was fire affected, and 12% for P. richmondensis. Field surveys revealed persistence in some burnt rainforest; however, both species were detected at a higher proportion of unburnt sites. There was a clear negative effect of fire on the probability of site occupancy, abundance and the probability of persistence for P. kundagungan. For P. richmondensis, effects of fire were less evident due to the limited penetration of fire into core habitat; however, occupancy rates and abundance of calling males were depressed during the severe drought that prevailed just prior to the fires, with the reappearance of calling males linked to the degree of rehydration of breeding habitat post-fire. Our results highlight the possibility that severe negative impacts of climate change for montane rainforest endemics may be felt much sooner than commonly anticipated under a scenario of gradual (decadal-scale) changes in mean climatic conditions. Instead, the increased rate of severe stochastic events places these narrow range species at a heightened risk of extinction in the near-term.

Adverse effects and potential mechanisms of fluxapyroxad in Xenopus laevis on carbohydrate and lipid metabolism

Fungicides are one of significant contributing factors to the rapid decline of amphibian species worldwide. Fluxapyroxad (FLX), an effective and broad-spectrum succinate dehydrogenase inhibitor fungicide, has attracted major concerns due to its long-lasting in the environment. However, the potential toxicity of FLX in the development of amphibians remains mostly unknown. In this research, the potential toxic effects and mechanisms of FLX on Xenopus laevis were investigated. In the acute toxicity test, the 96 h median lethal concentration (LC50) of FLX in X. laevis tadpoles was 1.645 mg/L. Based on the acute toxicity result, tadpoles at the stage 51 were exposed to 0, 0.00822, 0.0822, and 0.822 mg/L FLX during 21 days. Results demonstrated that FLX exposure led to an apparent delay in the growth and development of tadpoles and associated with severe liver injury. Additionally, FLX induced glycogen depletion and lipid accumulation in the liver of X. laevis. The biochemical analysis of plasma and liver indicated that FLX exposure could perturb liver glucose and lipid homeostasis by altering enzyme activity related to glycolysis, gluconeogenesis, fatty acid synthesis, and oxidation. Consistent with the biochemical result, FLX exposure altered the liver transcriptome profile, and the enrichment analysis of differential expression genes highlighted the adverse effects of FLX exposure on steroid biosynthesis, PPAR signaling pathway, glycolysis/gluconeogenesis, and fatty acid metabolism in the tadpole liver. Overall, our study was the first to reveal that sub-lethal concentrations of FLX could induce liver damage and produce obvious interference effects on carbohydrate and lipid metabolism of Xenopus, providing new insight into the potential chronic hazards of FLX for amphibians.

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.

In situ works on ecotoxicology in amphibians: current state of the art

Amphibians play a fundamental role in the functioning of ecosystems, mainly in the nutrient cycle, energy flow, and pest control. This group has a massive population decline, with approximately 41% of all species at risk, highlighting pesticide pollution as one of the main threats to the loss of anuran biodiversity. This occurs since amphibians have an epidermis with high permeability and a biphasic life cycle, where they use both the aquatic and terrestrial environments, allowing exposure and making them susceptible to chemical agents released into the environment. This makes amphibians a model group in ecotoxicological studies. However, due to the greater control of experimental conditions, the vast majority of studies are carried out in the laboratory, thus maintaining a gap in knowledge about the effects of pesticides on amphibians in natural environments. Under natural conditions, where environmental variables are not controlled, experiments must relate all the dynamics of the interaction of substances existing in the environment, and their influences on organisms. To evaluate the studies already performed under natural conditions, a bibliographic survey was carried out through a search with the Web of Science and SCOPUS databases, considering articles published in the last twenty years, using the terms 'field experimentation' or 'in situ study', associated with 'tadpole' and 'agrochemical' or 'pesticide', using a descriptive methodology. Twenty-one abstracts were pre-selected, they were further evaluated and the methodologies were checked to ensure only the analysis of experiments conducted in the field conditions. Thus, ten works were selected for the construction of the review. The works selected used native amphibian species, considered generalists, present in the study region, and were carried out in environments intended for agricultural cultivation with control groups in preserved locations. In these works, different methodologies were used, such as intentional spraying of water bodies, quantification of pesticides in the study sites, and verification of changes caused by the environment on tadpoles. The main evaluations were based on the survival and morphological changes of the tadpoles and, in some cases, on cytological and biochemical assays.

A Universal and Efficient Detection of Chytridiomycosis Infections in Amphibians Using Novel Quantitative PCR Markers

Chytridiomycosis is an infectious disease in amphibians caused by two chytrid fungi, Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal), and is the worst infectious disease known in wildlife so far. Worldwide spread of the disease has caused unprecedented loss of global amphibian diversity. Although some lineages of Bd are enzootic and are not as deadly as the pandemic lineage, nearly 40% of amphibian species are still declining globally due to chytridiomycosis. Efficient surveillance and monitoring of chytridiomycosis are the immediate safeguard against rapid declines or extinctions of amphibian populations. Previous studies showed that existing diagnostic assays were not sensitive to certain Bd haplotypes like those from Korea, China, India, Japan, and Brazil and thereby, there is a need for a universal, sensitive, specific, reproducible, and affordable diagnostic assay. We designed a one-step SYBR green-based quantitative polymerase chain reaction (nSYBR qPCR) for robust detection of Bd. It amplifies an 82 base-pair segment between the 5.8S rRNA and ITS2 of the Bd genome. The primer pair was tested in-silico on 40 isolates from four known Bd lineages. Using skin swab samples of wild amphibians and cultured zoospores from Australia and Panama, we compared the clinical specificity and sensitivity of the newly described primers to the existing TaqMan-based qPCR assay. From India, we used samples which had been previously tested with Nested PCR to validate the new primer pairs. The newly described primer pair was then tested on swab samples from Anura, Caudata and Gymnophiona from India. We report widespread chytridiomycosis with varying infection loads on them. The new assay showed comparable efficiency to the TaqMan-based qPCR assay. This diagnostic assay can facilitate widespread surveillance of chytridiomycosis where it has been previously absent, which may reveal several reservoirs of the pathogen and can improve our understanding of this important wildlife disease.

Terrestrial vertebrate and butterfly diversity of Garbhanga Landscape, Assam, India

A study was conducted on the current status of terrestrial vertebrates and butterflies in Garbhanga Reserve Forest. Data were compiled from field surveys and secondary sources like existing literature, and citizen science databases. We found that Garbhanga is represented by 254 species of butterflies (6 families), 29 species of amphibians (7 families), 64 species of reptiles (12 families), 307 species of birds (68 families) and 31 species of mammals (19 families). In Garbhanga, amongst the studied group, two species are ‘Critically Endangered’ (CR), six species are ‘Endangered’ (EN), 14 species are ‘Vulnerable’ (VU), eight species are ‘Near Threatened’ (NT), eight species are ‘Data Deficient’ (DD), 411 species are ‘Least Concern’ (LC), and 236 species are not assessed (denoted by blank space). This shows a huge gap in research and status evaluation of understudied species. This in turn also provides further research opportunities on the lesser known species.

Temperature variability and metabolic adaptation in terrestrial and aquatic ectotherms

Thermodynamics is a major factor determining rates of energy expenditure, rates of biochemical dynamics, and ultimately the biological and ecological processes linked with resilience to global warming in ectothermic organisms. Nonetheless, whether ectothermic organisms exhibit general adaptive metabolic responses to cope with worldwide variation in thermal conditions has remained as an open question. Here we combine a model comparison approach with a global dataset of standard metabolic rates (SMR), including 1,160 measurements across 788 species of aquatic invertebrates, insects, fishes, amphibians and reptiles, to investigate the association between metabolic rates and environmental temperatures in their respective habitats. Our analyses suggest that variation in SMR after removing allometric and thermodynamic effects is best explained by the temperature range encountered across seasons, which always provided a better fit than the average temperature for the hottest and coldest month and mean annual temperatures. This pattern was consistent across taxonomic groups and robust to sensitivity analyses. Nonetheless, aquatic and terrestrial lineages responded differently to seasonality, with SMR declining – 6.8% °C−1 of thermal range across seasons in aquatic organisms and increasing 2.8% °C−1 in terrestrial organisms. These responses may reflect alternative strategies to mitigate the impact of increments in warmer temperatures on energy expenditure, either by means of metabolic reduction in thermally homogeneous water bodies or effective behavioral thermoregulation to exploit temperature heterogeneity on land.

Severe wildfires promoted by climate change negatively impact forest amphibian metacommunities

AbstractAimChanges to the extent and severity of wildfires driven by anthropogenic climate change are predicted to have compounding negative consequences for ecological communities. While there is evidence that severe weather events like drought impact amphibian communities, the effects of wildfire on such communities are not well understood. The impact of wildfire on amphibian communities and species is likely to vary, owing to the diversity of their life‐history traits. However, no previous research has identified commonalities among the amphibians at most risk from wildfire, limiting conservation initiatives in the aftermath of severe wildfire. We aimed to investigate the impacts of the unprecedented 2019–2020 black summer bushfires on Australian forest amphibian communities.LocationEastern coast of New South Wales, Australia.MethodsWe conducted visual encounter surveys and passive acoustic monitoring across 411 sites within two regions, one in northeast and one in southeast New South Wales. We used fire severity and extent mapping in two multispecies occupancy models to assess the impacts of fire on 35 forest amphibian species.ResultsWe demonstrate a negative influence of severe fire extent on metacommunity occupancy and species richness in the south with weaker effects in the north—reflective of the less severe fires that occurred in this region. Both threatened and common species were impacted by severe wildfire extent. Occupancy of burrowing species and rain forest specialists had mostly negative relationships with severe wildfire extent, while arboreal amphibians had neutral relationships.Main ConclusionMetacommunity monitoring and adaptive conservation strategies are needed to account for common species after severe climatic events. Ecological, morphological and life‐history variation drives the susceptibility of amphibians to wildfires. We document the first evidence of climate change‐driven wildfires impacting temperate forest amphibian communities across a broad geographic area, which raises serious concern for the persistence of amphibians under an increasingly fire‐prone climate.

Spatial non-stationarity effect of determinants regulates variation in amphibian species richness

Despite the variation in amphibian biodiversity being often explained through environmental variables, the effects of spatial non-stationarity factors are too-often ignored as significant geographic characteristics, especially at large scales. Here, using a spatial regression approach through a multiscale analysis, we explored the spatial heterogeneity and scale effects in the impacts of environments on amphibian species richness across China. We showed that the impacts of variables varied with regions, and the individual scales specific to each variable were negatively correlated with effect sizes. We then demonstrated that climate variables, followed by topography, showed a high explanatory power for species richness in most areas, while the effects of precipitation and temperature were characterized by high geographical heterogeneity. In addition, elevation was positively related to local species richness in most plains, while being a main negative variable to species richness in the western highlands. The analysis of geographic heterogeneity showed that the explanatory power of most variables declined with increasing elevation. Although anthropogenic impacts contributed less than climatic variables, they significantly increased the sensitivity of amphibian species to environmental variations. Finally, to measure the aggregation pattern of heterogeneous effects of variables on species richness, we used a neural network to identify ecoregions regulated by similar variables and determined the presence of four ecologically consistent regions. Our findings provide further evidence supporting spatially variables regulators of amphibian diversity.

Captive breeding in the endangered alpine tree frog, Litoria verreauxii alpina.

Amphibians are experiencing dramatic worldwide declines and many species are reliant on captive breeding programs to ensure continued survival. However, captive breeding in amphibians is not always successful because many species, especially ones in decline, have particular and specific breeding needs. The endangered alpine tree frog, Litoria verreauxii alpina, has never been bred in captivity before. Due to its dramatic declines across the Australian Alps caused by the global pandemic chytridiomycosis, the species is a potential candidate for captive assurance colonies, which rely on captive breeding. For this study we tested hormone induction using two hormones that have had some success in other amphibian species, to no avail. We then tried outdoor breeding mesocosms during the winter/spring at temperatures similar to their natural breeding season, which was successful. Sixty-five percent of the egg masses laid successfully hatched tadpoles. Females laid more than one clutch over the experiment indicating either a shorter than annual ovulation cycle, or that females are capable of partial ovulation during breeding events. Outdoor breeding mesocosms are a possibility outside the native climate of a species, provided that temperatures overlap with their natural environment. Here, we highlight that troubleshooting is essential before embarking on a captive breeding program of a species that has not been bred before. Hormonal induction of breeding is not always successful; therefore, outdoor mesocosms might be required to achieve healthy tadpoles.

Monitoring the Diversity of Amphibian and Reptiles In the Upstream part of Code River Using e-DNA Method

Research on the diversity of amphibians and reptiles on the upstream part of Code River had been done in 2012 and 2017. Result on two previous results were found anurans, snakes and lizards but we did not find any freshwater turtles. Method used on the 2012 and 2017 research was conventional using Visual Encounter Survey (VES). Conventional methods such as VES have limitations, which was the inability to detect difficult-to-find animals such as freshwater turtles. Therefore, a new approach was taken to monitor the diversity of amphibians and reptiles especially to detect freshwater turtles in the Code River, namely the environmental DNA (eDNA) method. The purpose of this research were to monitor the diversity of amphibians and reptiles, and to reveals eDNA sampling efficiency compared to VES. An e-DNA metabarcoding process is conducted with universal CO1 primer on the water sample taken from upstream part of Code River. The results obtained were compared to the data from conventional studies held in 2012 and 2017. The results in 2021 found 12 species of amphibians but all of these species did not naturally distribute in Yogyakarta and even in Indonesia. Furthermore, 5 species of snakes were found, with only 1 species of snake naturally occur in Yogyakarta. Subsequently, we found 6 species of lizards whose natural distribution does not exist in Yogyakarta and even in Indonesia. Finally, we obtained 1 species of tortoise whose natural distribution does not exist in Yogyakarta and even in Indonesia. By far, in Indonesia the identification of amphibian and reptile species in rivers using the e-DNA method has shown less accurate results. The inaccuracy may be due to the lack of specificity of the sequence targets and primers for monitoring reptiles and amphibians in rivers. The target sequences used in this study did not have significant differences between species in reptiles and amphibians, so that the herpetofauna that had been recorded in the Code River were not identified using the e-DNA method. Based on this research, conventional sampling is recommended for monitoring herpetofauna in river areas.
 Keywords: Monitoring, Amphibians; Reptiles; Code River, e-DNA

Non-native species in Poyang Lake Basin: status, threats and management

Poyang Lake is the largest freshwater lake in China and sustains a high level of biodiversity in the mid-reach area of the Yangtze River watershed. Poyang Lake is also one of the most important aquaculture regions in China, and a great number of non-native species have been introduced into it. We present a current and well-documented list of the non-native species of plants, molluscs, crustaceans, fishes, reptiles, and amphibians currently found in Lake. We found that there are 103 non-native species (83 vascular plants, 12 fishes, three crustacea, two molluscs, two reptiles and one amphibian) that have invaded Poyang Lake Basin, of which 96 non-native species were introduced after 2000. The invasion rate of non-native species reached 4.36 species year-1, which is the highest invasion rate recorded in freshwater ecosystems. The primary pathways of introduction are through the ornamental trade and unintentional escapes (30 species each, respectively), followed by food (19), aquaculture (15), forage grass (four), medicinal and oil (two, respectively), and biocontrol (one). The origins of non-native species are North America (29.12%), Asia (25.24%), South America (20.38%), Africa (18.44%), Europe (5.82%) and Oceania (0.97%). Many non-native species provide significant support for the rapid development of the local economy (such as aquaculture). However, many non-native species pose a great threat to local biodiversity and societal development. More studies that include monitoring and the development of strategies for managing and eliminating non-native species in Poyang Lake are needed.

Evaluating fence-end treatments for migratory amphibians

Migratory amphibians require movements to complete their biphasic life cycle, often across altered landscapes fragmented by roadways, which can have severe consequences on their populations. To manage this threat, transportation agencies have begun to implement exclusion fencing to separate natural areas from the roadway to prevent wildlife-vehicle collisions. Although fences are an effective conservation tool, the tendency of animals to access the road by circumventing the fence ends, known as the fence-end effect, threatens to jeopardize management efforts to reduce road associated mortality. One strategy to lessen the impacts of the fence-end effect is to construct fence-end treatments to block amphibian movement and guide the animals to safe crossing locations. By using experimental fence arenas, we examined how nine amphibian species responded to two alternative fence-end structures: horizontal v-shape and perpendicular fence-end treatments. Using a generalized linear model framework, we found both fence-end treatments to be an effective strategy to reduce the impacts of the fence-end effect, with our predictor variable, fence-end treatment, explaining most of the variation in amphibian response. Structure effectiveness also started to improve by 20% with each 7°C increase in temperature, however, this was not significant. Despite these promising findings, we also found for each additional 312 s an amphibians spent attempting to navigate around the experimental fence resulted in a 25% decline in structure effectiveness, suggesting longer fences are not an adequate protection measure to combat the fence-end effect for amphibians. In addition, Anaxyrus americanus was not found to differ in their response, performing equally well to both experimental fence-end treatments. In contrast, Rana spp., Pseudacris crucifer, and Notopthalmus viridescens showed a greater response to the horizontal v-shape fence-end treatment compared to the perpendicular fence-end treatment. Variation in response for Ambystoma spp. could not be detected due to a small sample size; however, no individuals responded positively to the perpendicular fence-end treatment. Guidelines for amphibian fences should continue to incorporate fence-end treatments into the design and implementation to mitigate for the fence-end effect, and preferably angle the fence-ends inward in the horizontal v-shape pattern with the fence ends diagonal to the road for migratory amphibians.

Embryonic exposure to native and alien predator cues tunes tadpole defensive behaviour

When exposed to predation risk, some amphibian species show innate responses, while others recognize their predators by learning. To explore the role played by each mechanism in the assessment of predation risk, we investigated the effects of embryonic and larval exposure to predator chemical cues on tadpole defensive responses, including behavioural, morphological and life history traits. In the first experiment, agile frog (Rana dalmatina) embryos were exposed to the odour of either native (Aeshna cyanea larvae) or alien (Procambarus clarkii) predators each day from egg collection to hatchling (14 days). Body measures (mass, developmental stage, body length, tail length and tail depth) were recorded at hatching and a behavioural test was conducted to explore tadpole responses to predator cues and the potential interaction with their previous embryonic experience. In general, embryonic conditioning did not affect life history traits, except for a slight reduction in tail depth:length ratio for tadpoles exposed to odonate odours. Controls (embryos treated with water) after hatchling reduced their activity when exposed to gammarid-fed odonate cues, suggesting that responses were at least partially innate. Tadpoles exposed to odonate cues as embryos showed a strong defensive response when exposed to dragonfly kairomones. Tadpoles exposed to gammarid-fed crayfish as embryos showed clear behavioural responses towards the same cue (irrespectively of predator diet). Overall, our results suggest that embryonic exposure may tune the defensive responses of the larval stage and early exposure to naïve stimuli may promote their cautionary associations with predation risk.

Rediscovery and phylogenetic position of the glassfrog "Centrolene"acanthidiocephalum (Ruiz-Carranza and Lynch, 1989) (Anura: Centrolenidae)with the description of its advertisement call and comments on clutches and tadpoles.

The lack of basic natural history and distributional data represents a challenge for the conservation of rare and endemic amphibian species. This is the case of "Centrolene" acanthidiocephalum, a poorly known glassfrog endemic to the Cordillera Oriental of the Colombian Andes. This species was formally described in the late 1980s and no records have been reported over the last quarter century. Therefore, little is known about its distributional boundaries, morphological variation, natural history, and evolutionary relationships. Here we report the finding of a population of "Centrolene" acanthidiocephalum from a locality around its historical range and provide additional information on its geographic distribution, clutch size, and adult morphology. We also present for the first time data on tadpole morphology, as well as a description of its advertisement call and a phylogenetic tree based on mitochondrial genetic data corroborating its generic position within Centrolene.