WorldWideScience

Sample records for healthy amphibian populations

  1. Direct and Indirect Effects of Climate Change on Amphibian Populations

    OpenAIRE

    Blaustein, Andrew R.; Walls, Susan C.; Bancroft, Betsy A.; Lawler, Joshua J.; Searle, Catherine L.; Gervasi, Stephanie S.

    2010-01-01

    As part of an overall decline in biodiversity, populations of many organisms are declining and species are being lost at unprecedented rates around the world. This includes many populations and species of amphibians. Although numerous factors are affecting amphibian populations, we show potential direct and indirect effects of climate change on amphibians at the individual, population and community level. Shifts in amphibian ranges are predicted. Changes in climate may affect survival, growth...

  2. Direct and Indirect Effects of Climate Change on Amphibian Populations

    Directory of Open Access Journals (Sweden)

    Stephanie S. Gervasi

    2010-02-01

    Full Text Available As part of an overall decline in biodiversity, populations of many organisms are declining and species are being lost at unprecedented rates around the world. This includes many populations and species of amphibians. Although numerous factors are affecting amphibian populations, we show potential direct and indirect effects of climate change on amphibians at the individual, population and community level. Shifts in amphibian ranges are predicted. Changes in climate may affect survival, growth, reproduction and dispersal capabilities. Moreover, climate change can alter amphibian habitats including vegetation, soil, and hydrology. Climate change can influence food availability, predator-prey relationships and competitive interactions which can alter community structure. Climate change can also alter pathogen-host dynamics and greatly influence how diseases are manifested. Changes in climate can interact with other stressors such as UV-B radiation and contaminants. The interactions among all these factors are complex and are probably driving some amphibian population declines and extinctions.

  3. Amphibian Population Sensitivity to Environmental and ...

    Science.gov (United States)

    Anticipating chronic effects of contaminant exposure on amphibian species is complicated both by toxicological and ecological uncertainty. Data for both chemical exposures and amphibian vital rates, including altered growth, are sparse. Developmental plasticity in amphibians further complicates evaluation of chemical impacts as metamorphosis is also influenced by other biotic and abiotic stressors, such as temperature, hydroperiod, predation, and conspecific density. Determining the effect of delayed tadpole development on survival through metamorphosis and subsequent recruitment must include possible effects of pond drying accelerating metamorphosis near the end of the larval stage. This model considers the combined influence of delayed onset of metamorphosis in a cohort as well as accelerated metamorphosis toward the end of the hydroperiod and determines the net influence of counteracting forces on tadpole development and survival. Amphibian populations with greater initial density dependence have less capacity for developmental plasticity and are therefore more vulnerable to delayed development and reduced hydroperiod. The consequential reduction in larval survival has a relatively greater impact on species with a shorter lifespan, allowing for fewer breeding seasons during which to successfully produce offspring. In response to risk assessment approaches that consider only survival and reproductive endpoints in population evaluation, we calculate conta

  4. Effects of Roads on Amphibian Populations

    DEFF Research Database (Denmark)

    Hels, T.

    is the result of my three year PhD study at the National Environmental Research Institute, Kalø, and University of Copenhagen. Funded by NERI, the Danish Research Academy, and the Danish Road Directorate, it has dealt mainly with the effects of traffic and roads on amphibian populations. The Spadefoot toad...... of Spadefoot toads (Pelobates fuscus Laur.) II The effect of road kills on amphibian populations III Simulating viability of a Spadefoot toad (P. fuscus) metapopulation in a landscape fragmented by a road The manuscripts are preceded by a synopsis which sums up the work and puts it into a broader perspective......, Johan Elmberg, Andreas Seiler, and Per Sjögren-Gulve, for sharing your knowledge and enthusiasm for science with me. Constructive ideas, different approaches, and elaborate discussions are crucial parts of any scientific process: I thank Lenore Fahrig for dedicated and original teaching and discussions...

  5. Impact of forestry practices at a landscape scale on the dynamics of amphibian populations.

    Science.gov (United States)

    Harper, Elizabeth B; Patrick, David A; Gibbs, James P

    2015-12-01

    Forest loss is a primary cause of worldwide amphibian decline. Timber harvesting in the United States has caused dramatic changes in quality and extent of forest ecosystems, and intensive forest management still occurs. Although numerous studies have documented substantial reductions in amphibian densities related to timber harvest, subsequent extinctions are rare. To better understand the population dynamics that have allowed so many amphibian species to persist in the face of widespread forest disturbance, we developed spatially explicit metapopulation models for four forest-dependent amphibian species (Lithobates sylvaticus, Ambystoma opacum, A. talpoideum, and A. maculatum) that incorporated demographic and habitat selection data derived from experiments conducted as part of the Land Use Effects on Amphibian Populations Project (LEAP). We projected local and landscape-scale population persistence under 108 different forestry practice scenarios, varying treatment (partial cut, clear-cut with coarse woody debris [CWD] removed, and clearcut with CWD retained), cut patch size (1, 10, or 50 ha), total area cut (10, 20, or 30%), and initial amphibian population size (5, 50, or 500 adult females per local breeding population). Under these scenarios, landscape-scale extinction was highly unlikely, occurring in amphibian populations in the United States should focus not on questions of landscape-scale extinction but on the ecological consequences of dramatic reductions in amphibian biomass, including changes in trophic interactions, nutrient cycling, and energy transfer. Additionally, we conclude that amphibian declines and extinctions are far more likely to occur as a result of permanent habitat loss resulting from development than from the temporary degradation of habitat caused by current forestry practices.

  6. Differential patterns of Batrachochytrium dendrobatidis infection in relict amphibian populations following severe disease-associated declines.

    Science.gov (United States)

    Whitfield, Steven M; Alvarado, Gilbert; Abarca, Juan; Zumbado, Hector; Zuñiga, Ibrahim; Wainwright, Mark; Kerby, Jacob

    2017-09-20

    Global amphibian biodiversity has declined dramatically in the past 4 decades, and many amphibian species have declined to near extinction as a result of emergence of the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd). However, persistent or recovering populations of several amphibian species have recently been rediscovered, and such populations may illustrate how amphibian species that are highly susceptible to chytridiomycosis may survive in the presence of Bd. We conducted field surveys for Bd infection in 7 species of Costa Rican amphibians (all species that have declined to near extinction but for which isolated populations persist) to characterize infection profiles in highly Bd-susceptible amphibians post-decline. We found highly variable patterns in infection, with some species showing low prevalence (~10%) and low infection intensity and others showing high infection prevalence (>80%) and either low or high infection intensity. Across sites, infection rates were negatively associated with mean annual precipitation, and infection intensity across sites was negatively associated with mean average temperatures. Our results illustrate that even the most Bd-susceptible amphibians can persist in Bd-enzootic ecosystems, and that multiple ecological or evolutionary mechanisms likely exist for host-pathogen co-existence between Bd and the most Bd-susceptible amphibian species. Continued monitoring of these populations is necessary to evaluate population trends (continuing decline, stability, or population growth). These results should inform efforts to mitigate impacts of Bd on amphibians in the field.

  7. Analysis of three amphibian populations with quarter-century long time-series.

    OpenAIRE

    Meyer, A H; Schimidt, B R; Grossenbacher, K

    1998-01-01

    Amphibians are in decline in many parts of the world. Long tme-series of amphibian populations are necessary to distinguish declines from the often strong fluctuations observed in natural populations. Time-series may also help to understand the causes of these declines. We analysed 23-28-year long time-series of the frog Rana temporaria. Only one of the three studied populations showed a negative trend which was probably caused by the introduction of fish. Two populations appeared to be densi...

  8. A statistical assessment of population trends for data deficient Mexican amphibians

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    Esther Quintero

    2014-12-01

    Full Text Available Background. Mexico has the world’s fifth largest population of amphibians and the second country with the highest quantity of threatened amphibian species. About 10% of Mexican amphibians lack enough data to be assigned to a risk category by the IUCN, so in this paper we want to test a statistical tool that, in the absence of specific demographic data, can assess a species’ risk of extinction, population trend, and to better understand which variables increase their vulnerability. Recent studies have demonstrated that the risk of species decline depends on extrinsic and intrinsic traits, thus including both of them for assessing extinction might render more accurate assessment of threats.Methods. We harvested data from the Encyclopedia of Life (EOL and the published literature for Mexican amphibians, and used these data to assess the population trend of some of the Mexican species that have been assigned to the Data Deficient category of the IUCN using Random Forests, a Machine Learning method that gives a prediction of complex processes and identifies the most important variables that account for the predictions.Results. Our results show that most of the data deficient Mexican amphibians that we used have decreasing population trends. We found that Random Forests is a solid way to identify species with decreasing population trends when no demographic data is available. Moreover, we point to the most important variables that make species more vulnerable for extinction. This exercise is a very valuable first step in assigning conservation priorities for poorly known species.

  9. A statistical assessment of population trends for data deficient Mexican amphibians.

    Science.gov (United States)

    Quintero, Esther; Thessen, Anne E; Arias-Caballero, Paulina; Ayala-Orozco, Bárbara

    2014-01-01

    Background. Mexico has the world's fifth largest population of amphibians and the second country with the highest quantity of threatened amphibian species. About 10% of Mexican amphibians lack enough data to be assigned to a risk category by the IUCN, so in this paper we want to test a statistical tool that, in the absence of specific demographic data, can assess a species' risk of extinction, population trend, and to better understand which variables increase their vulnerability. Recent studies have demonstrated that the risk of species decline depends on extrinsic and intrinsic traits, thus including both of them for assessing extinction might render more accurate assessment of threats. Methods. We harvested data from the Encyclopedia of Life (EOL) and the published literature for Mexican amphibians, and used these data to assess the population trend of some of the Mexican species that have been assigned to the Data Deficient category of the IUCN using Random Forests, a Machine Learning method that gives a prediction of complex processes and identifies the most important variables that account for the predictions. Results. Our results show that most of the data deficient Mexican amphibians that we used have decreasing population trends. We found that Random Forests is a solid way to identify species with decreasing population trends when no demographic data is available. Moreover, we point to the most important variables that make species more vulnerable for extinction. This exercise is a very valuable first step in assigning conservation priorities for poorly known species.

  10. BIOTIC FACTORS IN AMPHIBIAN POPULATION DECLINES

    Science.gov (United States)

    Amphibians evolved in, and continue to exist in, habitats that are replete with many other organisms. Some of these organisms serve as prey for amphibians and others interact with amphibians as predators, competitors, pathogens, or symbionts. Still other organisms in their enviro...

  11. AMPHIBIAN DECLINE, ULTRAVIOLET RADIATION AND LOCAL POPULATION ADAPTATION

    Science.gov (United States)

    Amphibian population declines have been noted on both local and global scales. Causes for these declines are unknown although many hypotheses have been offered. In areas adjacent to human development, loss of habitat is a fairly well accepted cause. However in isolated, seemingl...

  12. Restored agricultural wetlands in Central Iowa: habitat quality and amphibian response

    Science.gov (United States)

    Reeves, Rebecca A.; Pierce, Clay; Smalling, Kelly L.; Klaver, Robert W.; Vandever, Mark W.; Battaglin, William A.; Muths, Erin L.

    2016-01-01

    Amphibians are declining throughout the United States and worldwide due, partly, to habitat loss. Conservation practices on the landscape restore wetlands to denitrify tile drainage effluent and restore ecosystem services. Understanding how water quality, hydroperiod, predation, and disease affect amphibians in restored wetlands is central to maintaining healthy amphibian populations in the region. We examined the quality of amphibian habitat in restored wetlands relative to reference wetlands by comparing species richness, developmental stress, and adult leopard frog (Lithobates pipiens) survival probabilities to a suite of environmental metrics. Although measured habitat variables differed between restored and reference wetlands, differences appeared to have sub-lethal rather than lethal effects on resident amphibian populations. There were few differences in amphibian species richness and no difference in estimated survival probabilities between wetland types. Restored wetlands had more nitrate and alkaline pH, longer hydroperiods, and were deeper, whereas reference wetlands had more amphibian chytrid fungus zoospores in water samples and resident amphibians exhibited increased developmental stress. Restored and reference wetlands are both important components of the landscape in central Iowa and maintaining a complex of fish-free wetlands with a variety of hydroperiods will likely contribute to the persistence of amphibians in this landscape.

  13. Rapid Response to Evaluate the Presence of Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) and Ranavirus in Wild Amphibian Populations in Madagascar

    Science.gov (United States)

    Kolby, Jonathan E.; Smith, Kristine M.; Ramirez, Sara D.; Rabemananjara, Falitiana; Pessier, Allan P.; Brunner, Jesse L.; Goldberg, Caren S.; Berger, Lee; Skerratt, Lee F.

    2015-01-01

    . Standardized population monitoring of key amphibian and reptile species should be established with urgency to enable early detection of potential impacts of disease emergence in this global biodiversity hotspot. PMID:26083349

  14. Rapid Response to Evaluate the Presence of Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis and Ranavirus in Wild Amphibian Populations in Madagascar.

    Directory of Open Access Journals (Sweden)

    Jonathan E Kolby

    disease. Standardized population monitoring of key amphibian and reptile species should be established with urgency to enable early detection of potential impacts of disease emergence in this global biodiversity hotspot.

  15. Rapid Response to Evaluate the Presence of Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) and Ranavirus in Wild Amphibian Populations in Madagascar.

    Science.gov (United States)

    Kolby, Jonathan E; Smith, Kristine M; Ramirez, Sara D; Rabemananjara, Falitiana; Pessier, Allan P; Brunner, Jesse L; Goldberg, Caren S; Berger, Lee; Skerratt, Lee F

    2015-01-01

    . Standardized population monitoring of key amphibian and reptile species should be established with urgency to enable early detection of potential impacts of disease emergence in this global biodiversity hotspot.

  16. First record of Saprolegnia sp. in an amphibian population in Colombia

    Directory of Open Access Journals (Sweden)

    Luis Daniel Prada-Salcedo

    2011-12-01

    Full Text Available Most research related to the decline of amphibians has been focused on the detection of the pathogenic fungus Batrachochytriumdendrobatidis. This fungus is the main pathogen detected around the world. However, research has shown the presence of another fungus,Saprolegnia ferax, as a cause of mortality in amphibians in North America. Our study suggests a possible interspecific transmissioncaused by the presence of rainbow trout; thus, amphibian declines may not be attributable only to the presence of a single pathogen, butto other organisms and factors. Materials and methods. Our study revealed the presence of Saprolegnia sp. in the Andean frog Atelopusmittermeieri using the imprinting technique with lactophenol blue staining, which allowed the typical structures of this fungus to beobserved. Results. The importance of this discovery is the presence of two pathogenic fungi, B. dendrobatidis and Saprolegnia, whichaffecting simultaneously a population of amphibians. This finding brings attention to the eventual presence of other microorganismsthat might be involved individually or collectively in the decline of amphibian species. Conclusions. This record suggests a possibletransmission between rainbow trout (Oncorhynchus mykiss, an introduced species in the highlands of Colombia, which shares thesame habitats with different species of amphibians in the Sanctuary of Flora and Fauna Guanentá in the upper river Fonce in the midCordillera Oriental of Colombia.

  17. DNA barcoding applied to ex situ tropical amphibian conservation programme reveals cryptic diversity in captive populations.

    Science.gov (United States)

    Crawford, Andrew J; Cruz, Catalina; Griffith, Edgardo; Ross, Heidi; Ibáñez, Roberto; Lips, Karen R; Driskell, Amy C; Bermingham, Eldredge; Crump, Paul

    2013-11-01

    Amphibians constitute a diverse yet still incompletely characterized clade of vertebrates, in which new species are still being discovered and described at a high rate. Amphibians are also increasingly endangered, due in part to disease-driven threats of extinctions. As an emergency response, conservationists have begun ex situ assurance colonies for priority species. The abundance of cryptic amphibian diversity, however, may cause problems for ex situ conservation. In this study we used a DNA barcoding approach to survey mitochondrial DNA (mtDNA) variation in captive populations of 10 species of Neotropical amphibians maintained in an ex situ assurance programme at El Valle Amphibian Conservation Center (EVACC) in the Republic of Panama. We combined these mtDNA sequences with genetic data from presumably conspecific wild populations sampled from across Panama, and applied genetic distance-based and character-based analyses to identify cryptic lineages. We found that three of ten species harboured substantial cryptic genetic diversity within EVACC, and an additional three species harboured cryptic diversity among wild populations, but not in captivity. Ex situ conservation efforts focused on amphibians are therefore vulnerable to an incomplete taxonomy leading to misidentification among cryptic species. DNA barcoding may therefore provide a simple, standardized protocol to identify cryptic diversity readily applicable to any amphibian community. © 2012 John Wiley & Sons Ltd.

  18. Amphibian population genetics in agricultural landscapes: does viniculture drive the population structuring of the European common frog (Rana temporaria?

    Directory of Open Access Journals (Sweden)

    Patrick P. Lenhardt

    2017-07-01

    Full Text Available Amphibian populations have been declining globally over the past decades. The intensification of agriculture, habitat loss, fragmentation of populations and toxic substances in the environment are considered as driving factors for this decline. Today, about 50% of the area of Germany is used for agriculture and is inhabited by a diverse variety of 20 amphibian species. Of these, 19 are exhibiting declining populations. Due to the protection status of native amphibian species, it is important to evaluate the effect of land use and associated stressors (such as road mortality and pesticide toxicity on the genetic population structure of amphibians in agricultural landscapes. We investigated the effects of viniculture on the genetic differentiation of European common frog (Rana temporaria populations in Southern Palatinate (Germany. We analyzed microsatellite data of ten loci from ten breeding pond populations located within viniculture landscape and in the adjacent forest block and compared these results with a previously developed landscape permeability model. We tested for significant correlation of genetic population differentiation and landscape elements, including land use as well as roads and their associated traffic intensity, to explain the genetic structure in the study area. Genetic differentiation among forest populations was significantly lower (median pairwise FST = 0.0041 at 5.39 km to 0.0159 at 9.40 km distance than between viniculture populations (median pairwise FST = 0.0215 at 2.34 km to 0.0987 at 2.39 km distance. Our analyses rejected isolation by distance based on roads and associated traffic intensity as the sole explanation of the genetic differentiation and suggest that the viniculture landscape has to be considered as a limiting barrier for R. temporaria migration, partially confirming the isolation of breeding ponds predicted by the landscape permeability model. Therefore, arable land may act as a sink habitat

  19. ALIEN SPECIES: THEIR ROLE IN AMPHIBIAN POPULATION DECLINES AND RESTORATION

    Science.gov (United States)

    Alien species (also referred to as exotic, invasive, introduced, or normative species) have been implicated as causal agents in population declines of many amphibian species. Herein, we evaluate the relative contributions of alien species and other factors in adversely affecting ...

  20. A new parameterization for integrated population models to document amphibian reintroductions.

    Science.gov (United States)

    Duarte, Adam; Pearl, Christopher A; Adams, Michael J; Peterson, James T

    2017-09-01

    Managers are increasingly implementing reintroduction programs as part of a global effort to alleviate amphibian declines. Given uncertainty in factors affecting populations and a need to make recurring decisions to achieve objectives, adaptive management is a useful component of these efforts. A major impediment to the estimation of demographic rates often used to parameterize and refine decision-support models is that life-stage-specific monitoring data are frequently sparse for amphibians. We developed a new parameterization for integrated population models to match the ecology of amphibians and capitalize on relatively inexpensive monitoring data to document amphibian reintroductions. We evaluate the capability of this model by fitting it to Oregon spotted frog (Rana pretiosa) monitoring data collected from 2007 to 2014 following their reintroduction within the Klamath Basin, Oregon, USA. The number of egg masses encountered and the estimated adult and metamorph abundances generally increased following reintroduction. We found that survival probability from egg to metamorph ranged from 0.01 in 2008 to 0.09 in 2009 and was not related to minimum spring temperatures, metamorph survival probability ranged from 0.13 in 2010-2011 to 0.86 in 2012-2013 and was positively related to mean monthly temperatures (logit-scale slope = 2.37), adult survival probability was lower for founders (0.40) than individuals recruited after reintroduction (0.56), and the mean number of egg masses per adult female was 0.74. Our study is the first to test hypotheses concerning Oregon spotted frog egg-to-metamorph and metamorph-to-adult transition probabilities in the wild and document their response at multiple life stages following reintroduction. Furthermore, we provide an example to illustrate how the structure of our integrated population model serves as a useful foundation for amphibian decision-support models within adaptive management programs. The integration of multiple, but

  1. Annual Report: 2014: Partners in Amphibian and Reptile Conservation (PARC)

    Science.gov (United States)

    Weir, Linda A.; Nanjappa, P.; Apodaca, J.J.; Williams, J.

    2015-01-01

    Partners in Amphibian and Reptile Conservation (PARC) was established in 1999 to address the widespread declines, extinctions, and range reductions of amphibians and reptiles, with a focus on conservation of taxa and habitats in North America. Amphibians and reptiles are affected by a broad range of human activities, both as incidental effects of habitat alteration and direct effects from overexploitation; these animals are also burdened by humans attitudes – that amphibians and reptiles are either dangerous or of little environmental or economic value. However, PARC members understand these taxa are important parts of our natural and cultural heritage and they serve important roles in ecosystems throughout the world. With many amphibians and reptiles classified as threatened with extinction, conservation to ensure healthy populations of these animals has never been more important. As you will see herein, PARC’s 15th anniversary has been marked with major accomplishments and an ever-increasing momentum. With your help, PARC can continue to build on its successes and protect these vital species.

  2. The hypothalamus-pituitary-thyroid axis in teleosts and amphibians: Endocrine disruption and its consequences to natural populations

    Science.gov (United States)

    Carr, J.A.; Patino, R.

    2011-01-01

    Teleosts and pond-breeding amphibians may be exposed to a wide variety of anthropogenic, waterborne contaminants that affect the hypothalamus-pituitary-thyroid (HPT) axis. Because thyroid hormone is required for their normal development and reproduction, the potential impact of HPT-disrupting contaminants on natural teleost and amphibian populations raises special concern. There is laboratory evidence indicating that persistent organic pollutants, heavy metals, pharmaceutical and personal care products, agricultural chemicals, and aerospace products may alter HPT activity, development, and reproduction in teleosts and amphibians. However, at present there is no evidence to clearly link contaminant-induced HPT alterations to impairments in teleost or amphibian population health in the field. Also, with the exception of perchlorate for which laboratory studies have shown a direct link between HPT disruption and adverse impacts on development and reproductive physiology, little is known about if or how other HPT-disrupting contaminants affect organismal performance. Future field studies should focus on establishing temporal associations between the presence of HPT-disrupting chemicals, the occurrence of HPT alterations, and adverse effects on development and reproduction in natural populations; as well as determining how complex mixtures of HPT contaminants affect organismal and population health. ?? 2010 Elsevier Inc.

  3. The hypothalamus–pituitary–thyroid axis in teleosts and amphibians: Endocrine disruption and its consequences to natural populations

    Science.gov (United States)

    Carr, J.A.; Patino, Reynaldo

    2011-01-01

    Teleosts and pond-breeding amphibians may be exposed to a wide variety of anthropogenic, waterborne contaminants that affect the hypothalamus-pituitary-thyroid (HPT) axis. Because thyroid hormone is required for their normal development and reproduction, the potential impact of HPT-disrupting contaminants on natural teleost and amphibian populations raises special concern. There is laboratory evidence indicating that persistent organic pollutants, heavy metals, pharmaceutical and personal care products, agricultural chemicals, and aerospace products may alter HPT activity, development, and reproduction in teleosts and amphibians. However, at present there is no evidence to clearly link contaminant-induced HPT alterations to impairments in teleost or amphibian population health in the field. Also, with the exception of perchlorate for which laboratory studies have shown a direct link between HPT disruption and adverse impacts on development and reproductive physiology, little is known about if or how other HPT-disrupting contaminants affect organismal performance. Future field studies should focus on establishing temporal associations between the presence of HPT-disrupting chemicals, the occurrence of HPT alterations, and adverse effects on development and reproduction in natural populations; as well as determining how complex mixtures of HPT contaminants affect organismal and population health.

  4. Mitigating amphibian chytridiomycosis in nature

    Science.gov (United States)

    Garner, Trenton W. J.; Schmidt, Benedikt R.; Martel, An; Pasmans, Frank; Muths, Erin L.; Cunningham, Andrew A.; Weldon, Che; Fisher, Matthew C.; Bosch, Jaime

    2016-01-01

    Amphibians across the planet face the threat of population decline and extirpation caused by the disease chytridiomycosis. Despite consensus that the fungal pathogens responsible for the disease are conservation issues, strategies to mitigate their impacts in the natural world are, at best, nascent. Reducing risk associated with the movement of amphibians, non-amphibian vectors and other sources of infection remains the first line of defence and a primary objective when mitigating the threat of disease in wildlife. Amphibian-associated chytridiomycete fungi and chytridiomycosis are already widespread, though, and we therefore focus on discussing options for mitigating the threats once disease emergence has occurred in wild amphibian populations. All strategies have shortcomings that need to be overcome before implementation, including stronger efforts towards understanding and addressing ethical and legal considerations. Even if these issues can be dealt with, all currently available approaches, or those under discussion, are unlikely to yield the desired conservation outcome of disease mitigation. The decision process for establishing mitigation strategies requires integrated thinking that assesses disease mitigation options critically and embeds them within more comprehensive strategies for the conservation of amphibian populations, communities and ecosystems.

  5. Heterogeneous responses of temperate-zone amphibian populations to climate change complicates conservation planning

    Science.gov (United States)

    Muths, Erin L.; Chambert, Thierry A.; Schmidt, B. R.; Miller, D. A. W.; Hossack, Blake R.; Joly, P.; Grolet, O.; Green, D. M.; Pilliod, David S.; Cheylan, M.; Fisher, Robert N.; McCaffery, R. M.; Adams, M. J.; Palen, W. J.; Arntzen, J. W.; Garwood, J.; Fellers, Gary M.; Thirion, J. M.; Grant, Evan H. Campbell; Besnard, A.

    2017-01-01

    The pervasive and unabated nature of global amphibian declines suggests common demographic responses to a given driver, and quantification of major drivers and responses could inform broad-scale conservation actions. We explored the influence of climate on demographic parameters (i.e., changes in the probabilities of survival and recruitment) using 31 datasets from temperate zone amphibian populations (North America and Europe) with more than a decade of observations each. There was evidence for an influence of climate on population demographic rates, but the direction and magnitude of responses to climate drivers was highly variable among taxa and among populations within taxa. These results reveal that climate drivers interact with variation in life-history traits and population-specific attributes resulting in a diversity of responses. This heterogeneity complicates the identification of conservation ‘rules of thumb’ for these taxa, and supports the notion of local focus as the most effective approach to overcome global-scale conservation challenges.

  6. UV-B Radiation Contributes to Amphibian Population Declines

    Science.gov (United States)

    Blaustein, Andrew

    2007-05-01

    UV-B (280-315 nm) radiation is the most significant biologically damaging radiation at the terrestrial surface. At the organismal level, UV-B radiation can slow growth rates, cause immune dysfunction and result in sublethal damage. UV-B radiation can lead to mutations and cell death. Over evolutionary time, UV radiation has been an important stressor on living organisms. Natural events, including impacts from comets and asteroids, volcanic activity, supernova explosions and solar flares, can cause large-scale ozone depletion with accompanying increases in UV radiation. However, these natural events are transient. Moreover, the amount of ozone damage due to natural events depends upon a number of variables, including the magnitude of the event. This is different from modern-day human-induced production of chlorofluorocarbons (CFCs) and other chemicals that deplete stratospheric ozone continuously, resulting in long-term increases in UV-B radiation at the surface of the earth. We will briefly review the effects of UV-B exposure in one group of aquatic organisms_amphibians. UV-B has been implicated as a possible factor contributing to global declines and range reductions in amphibian populations.

  7. Garter snakes distributions in high elevation aquatic ecosystems: Is there a link with declining amphibian populations and nonnative trout introductions?

    Science.gov (United States)

    K.R. Matthews; R.A. Knapp; K.L. Pope

    2002-01-01

    ABSTRACT.—The dramatic amphibian population declines reported worldwide likely have important effects on their predators. In the Sierra Nevada, where amphibian declines are well documented and some are closely tied to the introduction of nonnative trout, the mountain garter snake, Thamnophis elegans elegans, preys predominately on amphibians. We surveyed 2103 high-...

  8. Overview of chytrid emergence and impacts on amphibians

    Science.gov (United States)

    2016-01-01

    Chytridiomycosis is an emerging infectious disease of amphibians that affects over 700 species on all continents where amphibians occur. The amphibian–chytridiomycosis system is complex, and the response of any amphibian species to chytrid depends on many aspects of the ecology and evolutionary history of the amphibian, the genotype and phenotype of the fungus, and how the biological and physical environment can mediate that interaction. Impacts of chytridiomycosis on amphibians are varied; some species have been driven extinct, populations of others have declined severely, whereas still others have not obviously declined. Understanding patterns and mechanisms of amphibian responses to chytrids is critical for conservation and management. Robust estimates of population numbers are needed to identify species at risk, prioritize taxa for conservation actions, design management strategies for managing populations and species, and to develop effective measures to reduce impacts of chytrids on amphibians. This article is part of the themed issue ‘Tackling emerging fungal threats to animal health, food security and ecosystem resilience’. PMID:28080989

  9. Differences in sensitivity to the fungal pathogen Batrachochytrium dendrobatidis among amphibian populations

    Science.gov (United States)

    Paul W. Bradley; Stephanie S. Gervasi; Jessica Hua; Rickey D. Cothran; Rick A. Relyea; Deanna H. Olson; Andrew R. Blaustein

    2015-01-01

    Contributing to the worldwide biodiversity crisis are emerging infectious diseases, which can lead to extirpations and extinctions of hosts. For example, the infectious fungal pathogen Batrachochytrium dendrobatidis (Bd) is associated with worldwide amphibian population declines and extinctions. Sensitivity to Bd varies with species, season, and life stage. However,...

  10. Amphibian responses to wildfire in the western united states: Emerging patterns from short-term studies

    Science.gov (United States)

    Hossack, B.R.; Pilliod, D.S.

    2011-01-01

    The increased frequency and severity of large wildfires in the western United States is an important ecological and management issue with direct relevance to amphibian conservation. Although the knowledge of fire effects on amphibians in the region is still limited relative to most other vertebrate species, we reviewed the current literature to determine if there are evident patterns that might be informative for conservation or management strategies. Of the seven studies that compared pre- and post-wildfire data on a variety of metrics, ranging from amphibian occupancy to body condition, two reported positive responses and five detected negative responses by at least one species. Another seven studies used a retrospective approach to compare effects of wildfire on populations: two studies reported positive effects, three reported negative effects from wildfire, and two reported no effects. All four studies that included plethodontid salamanders reported negative effects on populations or individuals; these effects were greater in forests where fire had been suppressed and in areas that burned with high severity. Species that breed in streams are also vulnerable to post-wildfire changes in habitat, especially in the Southwest. Wildfire is also important for maintaining suitable habitat for diverse amphibian communities, although those results may not be evident immediately after an area burns. We expect that wildfire will extirpate few healthy amphibian populations, but it is still unclear how populations will respond to wildfire in the context of land management (including pre- and post-fire timber harvest) and fragmentation. Wildfire may also increase the risk of decline or extirpation for small, isolated, or stressed (e.g., from drought or disease) populations. Improved understanding of how these effects vary according to changes in fire frequency and severity are critical to form more effective conservation strategies for amphibians in the western United States.

  11. Batrachochytrium dendrobatidis infection patterns among Panamanian amphibian species, habitats and elevations during epizootic and enzootic stages.

    Science.gov (United States)

    Brem, Forrest M R; Lips, Karen R

    2008-09-24

    The pathogenic fungus Batrachochytrium dendrobatidis (Bd) has caused declines of many amphibian populations, yet the full course of the epizootic has rarely been observed in wild populations. We determined effects of elevation, habitat, and aquatic index (AI) on prevalence of infection among Panamanian amphibians sampled along 2 elevational transects. Amphibian populations on the Santa Fé transect (SFT) had declined in 2002, while those on the El Copé transect (ECT) were healthy until September 2004. In 2004 we sampled Bd along both transects, surveying the SFT 2 yr after decline, and surveying the ECT 4 mo prior to the arrival of Bd, during the epizootic, and 2 mo later. Overall prevalence of Bd along the ECT increased from 0.0 (95% CI 0.00-0.0003) to 0.51 (95% CI 0.48-0.55) over a 3 mo period, accompanied by significant decreases in amphibian abundance and species richness in all habitats. Prevalence of infection on the ECT was highest along riparian transects and at higher elevations, but not among levels of AI. Prevalence of infection on the SFT was highest in pool transects, and at higher elevations, but not among levels of AI. Riparian amphibian abundance and species richness also declined at SFT following detection of Bd in 2002. Variation among species, microenvironmental conditions, and the length of coexistence with Bd may contribute to observed differences in prevalence of Bd and in population response.

  12. Hydrologic variability governs population dynamics of a vulnerable amphibian in an arid environment.

    Directory of Open Access Journals (Sweden)

    Erin R Zylstra

    Full Text Available Dynamics of many amphibian populations are governed by the distribution and availability of water. Therefore, understanding the hydrological mechanisms that explain spatial and temporal variation in occupancy and abundance will improve our ability to conserve and recover populations of vulnerable amphibians. We used 16 years of survey data from intermittent mountain streams in the Sonoran Desert to evaluate how availability of surface water affected survival and adult recruitment of a threatened amphibian, the lowland leopard frog (Lithobates yavapaiensis. Across the entire study period, monthly survival of adults ranged from 0.72 to 0.99 during summer and 0.59 to 0.94 during winter and increased with availability of surface water (Z = 7.66; P < 0.01. Recruitment of frogs into the adult age class occurred primarily during winter and ranged from 1.9 to 3.8 individuals/season/pool; like survival, recruitment increased with availability of surface water (Z = 3.67; P < 0.01. Although abundance of frogs varied across seasons and years, we found no evidence of a systematic trend during the 16-year study period. Given the strong influence of surface water on population dynamics of leopard frogs, conservation of many riparian obligates in this and similar arid regions likely depends critically on minimizing threats to structures and ecosystem processes that maintain surface waters. Understanding the influence of surface-water availability on riparian organisms is particularly important because climate change is likely to decrease precipitation and increase ambient temperatures in desert riparian systems, both of which have the potential to alter fundamentally the hydrology of these systems.

  13. Effects of road mortality and mitigation measures on amphibian populations.

    Science.gov (United States)

    Beebee, Trevor J C

    2013-08-01

    Road mortality is a widely recognized but rarely quantified threat to the viability of amphibian populations. The global extent of the problem is substantial and factors affecting the number of animals killed on highways include life-history traits and landscape features. Secondary effects include genetic isolation due to roads acting as barriers to migration. Long-term effects of roads on population dynamics are often severe and mitigation methods include volunteer rescues and under-road tunnels. Despite the development of methods that reduce road kill in specific locations, especially under-road tunnels and culverts, there is scant evidence that such measures will protect populations over the long term. There also seems little likelihood that funding will be forthcoming to ameliorate the problem at the scale necessary to prevent further population declines. © 2013 Society for Conservation Biology.

  14. The state of amphibians in the United States

    Science.gov (United States)

    Muths, E.; Adams, M.J.; Grant, E.H.C.; Miller, D.; Corn, P.S.; Ball, L.C.

    2012-01-01

    More than 25 years ago, scientists began to identify unexplained declines in amphibian populations around the world. Much has been learned since then, but amphibian declines have not abated and the interactions among the various threats to amphibians are not clear. Amphibian decline is a problem of local, national, and international scope that can affect ecosystem function, biodiversity, and commerce. This fact sheet provides a snapshot of the state of the amphibians and introduces examples to illustrate the range of issues in the United States.

  15. Book review: The ecology and behavior of amphibians

    Science.gov (United States)

    Walls, Susan C.

    2008-01-01

    This state‐of‐the‐art book has made its timely emergence amid a crisis of global magnitude: that of population declines, range reductions, and extinctions of numerous species of amphibians. A clear understanding of the fundamental concepts in amphibian biology is crucial to the success of any conservation effort. This volume compiles the information necessary to acquire that basic understanding. It is a comprehensive synthesis of both traditional and contemporary facets of amphibian biology, spanning a breadth of topics ranging from phylogeny, physiology, behavior, population and community ecology, and conservation. As such, it undoubtedly takes its place among contemporary volumes as the single, authoritative source for basic topics relevant to amphibian life.

  16. Ecophysiology meets conservation: understanding the role of disease in amphibian population declines

    Science.gov (United States)

    Blaustein, Andrew R.; Gervasi, Stephanie S.; Johnson, Pieter T. J.; Hoverman, Jason T.; Belden, Lisa K.; Bradley, Paul W.; Xie, Gisselle Y.

    2012-01-01

    Infectious diseases are intimately associated with the dynamics of biodiversity. However, the role that infectious disease plays within ecological communities is complex. The complex effects of infectious disease at the scale of communities and ecosystems are driven by the interaction between host and pathogen. Whether or not a given host–pathogen interaction results in progression from infection to disease is largely dependent on the physiological characteristics of the host within the context of the external environment. Here, we highlight the importance of understanding the outcome of infection and disease in the context of host ecophysiology using amphibians as a model system. Amphibians are ideal for such a discussion because many of their populations are experiencing declines and extinctions, with disease as an important factor implicated in many declines and extinctions. Exposure to pathogens and the host's responses to infection can be influenced by many factors related to physiology such as host life history, immunology, endocrinology, resource acquisition, behaviour and changing climates. In our review, we discuss the relationship between disease and biodiversity. We highlight the dynamics of three amphibian host–pathogen systems that induce different effects on hosts and life stages and illustrate the complexity of amphibian–host–parasite systems. We then review links between environmental stress, endocrine–immune interactions, disease and climate change. PMID:22566676

  17. Perspectives from the Aldo Leopold Wilderness Research Institute: Amphibians and wilderness

    Science.gov (United States)

    Corn, Paul Stephen

    2001-01-01

    The decline of amphibian species has emerged as a major global conservation issue in the last decade. Last year, the Department of the Interior (DOI) initiated a major national initiative to detect trends in amphibian populations and research the causes of declines. The program, conducted principally by the U.S. Geological Survey (USGS), emphasizes lands managed by DOI, but collaboration with the Forest Service is encouraged to increase the scope of inference about population trends. Although amphibians are not usually the first group of animals that comes to mind when one thinks of wilderness, conservation of amphibian populations is clearly a wilderness issue.

  18. Amphibians of the northern Great Plains

    Science.gov (United States)

    Larson, Diane L.; Euliss, Ned H.; Lannoo, Michael J.; Mushet, David M.; Mac, M.J.; Opler, P.A.; Puckett Haecker, C. E.; Doran, P.D.

    1998-01-01

    No cry of alarm has been sounded over the fate of amphibian populations in the northern grasslands of North America, yet huge percentages of prairie wetland habitat have been lost, and the destruction continues. Scarcely 30% of the original mixedgrass prairie remains in Nebraska, South Dakota, and North Dakota (See Table 1 in this chapter). If amphibian populations haven’t declined, why haven’t they? Or, have we simply failed to notice? Amphibians in the northern grasslands evolved in a boom-or-bust environment: species that were unable to survive droughts lasting for years died out long before humans were around to count them. Species we find today are expert at seizing the rare, wet moment to rebuild their populations in preparation for the next dry season. When numbers can change so rapidly, who can say if a species is rare or common? A lot depends on when you look.

  19. Amphibian populations in the terrestrial environment: Is there evidence of declines of terrestrial forest amphibians in northwestern California?

    Science.gov (United States)

    Hartwell H. Welsh Jr.; Gary M. Fellers; Amy J. Lind

    2007-01-01

    Amphibian declines have been documented worldwide; however the vast majority are species associated with aquatic habitats. Information on the status and trends of terrestrial amphibians is almost entirely lacking. Here we use data collected across a 12-yr period (sampling from 1984–86 and from 1993–95) to address the question of whether evidence exists for declines...

  20. Amphibian and reptile declines over 35 years at La Selva, Costa Rica.

    Science.gov (United States)

    Whitfield, Steven M; Bell, Kristen E; Philippi, Thomas; Sasa, Mahmood; Bolaños, Federico; Chaves, Gerardo; Savage, Jay M; Donnelly, Maureen A

    2007-05-15

    Amphibians stand at the forefront of a global biodiversity crisis. More than one-third of amphibian species are globally threatened, and over 120 species have likely suffered global extinction since 1980. Most alarmingly, many rapid declines and extinctions are occurring in pristine sites lacking obvious adverse effects of human activities. The causes of these "enigmatic" declines remain highly contested. Still, lack of long-term data on amphibian populations severely limits our understanding of the distribution of amphibian declines, and therefore the ultimate causes of these declines. Here, we identify a systematic community-wide decline in populations of terrestrial amphibians at La Selva Biological Station, a protected old-growth lowland rainforest in lower Central America. We use data collected over 35 years to show that population density of all species of terrestrial amphibians has declined by approximately 75% since 1970, and we show identical trends for all species of common reptiles. The trends we identify are neither consistent with recent emergence of chytridiomycosis nor the climate-linked epidemic hypothesis, two leading putative causes of enigmatic amphibian declines. Instead, our data suggest that declines are due to climate-driven reductions in the quantity of standing leaf litter, a critical microhabitat for amphibians and reptiles in this assemblage. Our results raise further concerns about the global persistence of amphibian populations by identifying widespread declines in species and habitats that are not currently recognized as susceptible to such risks.

  1. Impending conservation crisis for Southeast Asian amphibians.

    Science.gov (United States)

    Rowley, Jodi; Brown, Rafe; Bain, Raoul; Kusrini, Mirza; Inger, Robert; Stuart, Bryan; Wogan, Guin; Thy, Neang; Chan-Ard, Tanya; Trung, Cao Tien; Diesmos, Arvin; Iskandar, Djoko T; Lau, Michael; Ming, Leong Tzi; Makchai, Sunchai; Truong, Nguyen Quang; Phimmachak, Somphouthone

    2010-06-23

    With an understudied amphibian fauna, the highest deforestation rate on the planet and high harvesting pressures, Southeast Asian amphibians are facing a conservation crisis. Owing to the overriding threat of habitat loss, the most critical conservation action required is the identification and strict protection of habitat assessed as having high amphibian species diversity and/or representing distinctive regional amphibian faunas. Long-term population monitoring, enhanced survey efforts, collection of basic biological and ecological information, continued taxonomic research and evaluation of the impact of commercial trade for food, medicine and pets are also needed. Strong involvement of regional stakeholders, students and professionals is essential to accomplish these actions.

  2. Differential host susceptibility to Batrachochytrium dendrobatidis, an emerging amphibian pathogen

    Science.gov (United States)

    C.L. Searle; S.S. Gervasi; J. Hua; J.I. Hammond; R.A. Relyea; D.H. Olson; A.R. Blaustein

    2011-01-01

    The amphibian fungal pathogen Batrachochytrium dendrobatidis (Bd) has received considerable attention due to its role in amphibian population declines worldwide. Although many amphibian species appear to be affected by Bd, there is little information on species-specific differences in susceptibility to this pathogen. We used a comparative...

  3. Batrachochytrium salamandrivorans sp. nov. causes lethal chytridiomycosis in amphibians.

    Science.gov (United States)

    Martel, An; Spitzen-van der Sluijs, Annemarieke; Blooi, Mark; Bert, Wim; Ducatelle, Richard; Fisher, Matthew C; Woeltjes, Antonius; Bosman, Wilbert; Chiers, Koen; Bossuyt, Franky; Pasmans, Frank

    2013-09-17

    The current biodiversity crisis encompasses a sixth mass extinction event affecting the entire class of amphibians. The infectious disease chytridiomycosis is considered one of the major drivers of global amphibian population decline and extinction and is thought to be caused by a single species of aquatic fungus, Batrachochytrium dendrobatidis. However, several amphibian population declines remain unexplained, among them a steep decrease in fire salamander populations (Salamandra salamandra) that has brought this species to the edge of local extinction. Here we isolated and characterized a unique chytrid fungus, Batrachochytrium salamandrivorans sp. nov., from this salamander population. This chytrid causes erosive skin disease and rapid mortality in experimentally infected fire salamanders and was present in skin lesions of salamanders found dead during the decline event. Together with the closely related B. dendrobatidis, this taxon forms a well-supported chytridiomycete clade, adapted to vertebrate hosts and highly pathogenic to amphibians. However, the lower thermal growth preference of B. salamandrivorans, compared with B. dendrobatidis, and resistance of midwife toads (Alytes obstetricans) to experimental infection with B. salamandrivorans suggest differential niche occupation of the two chytrid fungi.

  4. Disease risk in temperate amphibian populations is higher at closed-canopy sites.

    Directory of Open Access Journals (Sweden)

    C Guilherme Becker

    Full Text Available Habitat loss and chytridiomycosis (a disease caused by the chytrid fungus Batrachochytrium dendrobatidis - Bd are major drivers of amphibian declines worldwide. Habitat loss regulates host-pathogen interactions by altering biotic and abiotic factors directly linked to both host and pathogen fitness. Therefore, studies investigating the links between natural vegetation and chytridiomycosis require integrative approaches to control for the multitude of possible interactions of biological and environmental variables in spatial epidemiology. In this study, we quantified Bd infection dynamics across a gradient of natural vegetation and microclimates, looking for causal associations between vegetation cover, multiple microclimatic variables, and pathogen prevalence and infection intensity. To minimize the effects of host diversity in our analyses, we sampled amphibian populations in the Adirondack Mountains of New York State, a region with relatively high single-host dominance. We sampled permanent ponds for anurans, focusing on populations of the habitat generalist frog Lithobates clamitans, and recorded various biotic and abiotic factors that potentially affect host-pathogen interactions: natural vegetation, canopy density, water temperature, and host population and community attributes. We screened for important explanatory variables of Bd infections and used path analyses to statistically test for the strength of cascading effects linking vegetation cover, microclimate, and Bd parameters. We found that canopy density, natural vegetation, and daily average water temperature were the best predictors of Bd. High canopy density resulted in lower water temperature, which in turn predicted higher Bd prevalence and infection intensity. Our results confirm that microclimatic shifts arising from changes in natural vegetation play an important role in Bd spatial epidemiology, with areas of closed canopy favoring Bd. Given increasing rates of anthropogenic

  5. Microevolution due to pollution in amphibians: A review on the genetic erosion hypothesis

    International Nuclear Information System (INIS)

    Fasola, E.; Ribeiro, R.; Lopes, I.

    2015-01-01

    The loss of genetic diversity, due to exposure to chemical contamination (genetic erosion), is a major threat to population viability. Genetic erosion is the loss of genetic variation: the loss of alleles determining the value of a specific trait or set of traits. Almost a third of the known amphibian species is considered to be endangered and a decrease of genetic variability can push them to the verge of extinction. This review indicates that loss of genetic variation due to chemical contamination has effects on: 1) fitness, 2) environmental plasticity, 3) co-tolerance mechanisms, 4) trade-off mechanisms, and 5) tolerance to pathogens in amphibian populations. - Highlights: • Effects of environmental stressors on the genetic diversity of natural populations of amphibians have usually been underestimated. • Environmental pollution may reduce the genetic diversity of exposed amphibian populations. • Genetic erosion can lead to reduced fitness and lack of adaptability to a changing environment. - Contaminant-driven genetic erosion is a major threat to population viability in amphibians

  6. Vulnerability of amphibians to climate change: implications for rangeland management

    Science.gov (United States)

    Karen E. Bagne; Deborah M. Finch; Megan M. Friggens

    2011-01-01

    Many amphibian populations have declined drastically in recent years due to a large number of factors including the emerging threat of climate change (Wake 2007). Rangelands provide important habitat for amphibians. In addition to natural wetlands, stock tanks and other artificial water catchments provide habitat for many amphibian species (Euliss et al. 2004).

  7. Estimating Herd Immunity to Amphibian Chytridiomycosis in Madagascar Based on the Defensive Function of Amphibian Skin Bacteria

    OpenAIRE

    Bletz, Molly C.; Myers, Jillian; Woodhams, Douglas C.; Rabemananjara, Falitiana C. E.; Rakotonirina, Angela; Weldon, Che; Edmonds, Devin; Vences, Miguel; Harris, Reid N.

    2017-01-01

    For decades, Amphibians have been globally threatened by the still expanding infectious disease, chytridiomycosis. Madagascar is an amphibian biodiversity hotspot where Batrachochytrium dendrobatidis (Bd) has only recently been detected. While no Bd-associated population declines have been reported, the risk of declines is high when invasive virulent lineages become involved. Cutaneous bacteria contribute to host innate immunity by providing defense against pathogens for numerous animals, inc...

  8. Differences in sensitivity to the fungal pathogen Batrachochytrium dendrobatidis among amphibian populations.

    Science.gov (United States)

    Bradley, Paul W; Gervasi, Stephanie S; Hua, Jessica; Cothran, Rickey D; Relyea, Rick A; Olson, Deanna H; Blaustein, Andrew R

    2015-10-01

    Contributing to the worldwide biodiversity crisis are emerging infectious diseases, which can lead to extirpations and extinctions of hosts. For example, the infectious fungal pathogen Batrachochytrium dendrobatidis (Bd) is associated with worldwide amphibian population declines and extinctions. Sensitivity to Bd varies with species, season, and life stage. However, there is little information on whether sensitivity to Bd differs among populations, which is essential for understanding Bd-infection dynamics and for formulating conservation strategies. We experimentally investigated intraspecific differences in host sensitivity to Bd across 10 populations of wood frogs (Lithobates sylvaticus) raised from eggs to metamorphosis. We exposed the post-metamorphic wood frogs to Bd and monitored survival for 30 days under controlled laboratory conditions. Populations differed in overall survival and mortality rate. Infection load also differed among populations but was not correlated with population differences in risk of mortality. Such population-level variation in sensitivity to Bd may result in reservoir populations that may be a source for the transmission of Bd to other sensitive populations or species. Alternatively, remnant populations that are less sensitive to Bd could serve as sources for recolonization after epidemic events. © 2015 Society for Conservation Biology.

  9. The metamorphosis of amphibian toxicogenomics

    Directory of Open Access Journals (Sweden)

    Caren eHelbing

    2012-03-01

    Full Text Available Amphibians are important vertebrates in toxicology often representing both aquatic and terrestrial forms within the life history of the same species. Of the thousands of species, only two have substantial genomics resources: the recently published genome of the Pipid, Xenopus (Silurana tropicalis, and transcript information (and ongoing genome sequencing project of Xenopus laevis. However, many more species representative of regional ecological niches and life strategies are used in toxicology worldwide. Since Xenopus species diverged from the most populous frog family, the Ranidae, ~200 million years ago, there are notable differences between them and the even more distant Caudates (salamanders and Caecilians. These differences include genome size, gene composition, and extent of polyploidization. Application of toxicogenomics to amphibians requires the mobilization of resources and expertise to develop de novo sequence assemblies and analysis strategies for a broader range of amphibian species. The present mini-review will present the advances in toxicogenomics as pertains to amphibians with particular emphasis upon the development and use of genomic techniques (inclusive of transcriptomics, proteomics, and metabolomics and the challenges inherent therein.

  10. Questions concerning the potential impact of glyphosate-based herbicides on amphibians.

    Science.gov (United States)

    Wagner, Norman; Reichenbecher, Wolfram; Teichmann, Hanka; Tappeser, Beatrix; Lötters, Stefan

    2013-08-01

    Use of glyphosate-based herbicides is increasing worldwide. The authors review the available data related to potential impacts of these herbicides on amphibians and conduct a qualitative meta-analysis. Because little is known about environmental concentrations of glyphosate in amphibian habitats and virtually nothing is known about environmental concentrations of the substances added to the herbicide formulations that mainly contribute to adverse effects, glyphosate levels can only be seen as approximations for contamination with glyphosate-based herbicides. The impact on amphibians depends on the herbicide formulation, with different sensitivity of taxa and life stages. Effects on development of larvae apparently are the most sensitive endpoints to study. As with other contaminants, costressors mainly increase adverse effects. If and how glyphosate-based herbicides and other pesticides contribute to amphibian decline is not answerable yet due to missing data on how natural populations are affected. Amphibian risk assessment can only be conducted case-specifically, with consideration of the particular herbicide formulation. The authors recommend better monitoring of both amphibian populations and contamination of habitats with glyphosate-based herbicides, not just glyphosate, and suggest including amphibians in standardized test batteries to study at least dermal administration. Copyright © 2013 SETAC.

  11. Ecotoxicology of Amphibians and Reptiles

    Science.gov (United States)

    2000-01-01

    For many years, ecological research on amphibians and reptiles has lagged behind that of other vertebrates such as fishes, birds, and mammals, despite the known importance of these animals in their environments. The lack of study has been particularly acute in the he area of ecotoxicology where the number of published scientific papers is a fraction of that found for the other vertebrate classes. Recently, scientists have become aware of severe crises among amphibian populations, including unexplained and sudden extinctions, worldwide declines, and hideous malformations. In many of these instances, contaminants have been listed as probable contributors. Data on the effects of contaminants on reptiles are so depauperate that even the most elementary interpretations are difficult. This state-of-the-science review and synthesis of amphibian and reptile ecotoxicology demonstrates the inter-relationships among distribution, ecology, physiology, and contaminant exposure, and interprets these topics as they pertain to comparative toxicity, population declines, malformations, and risk assessment . In this way, the book identifies and serves as a basis for the most pressing research needs in the coming years. The editors have invited 27 other internationally respected experts to examine the state of existing data in specific areas, interpret it in light of current problems, and identify research gaps and needs. Through its emphasis on recent research, extensive reviews and synthesis, Ecotoxicology of Amphibians and Reptiles will remain a definitive reference work well into the new century.

  12. Reptiles and Amphibians of Fairchild Air Force Base, WA

    Science.gov (United States)

    2013-05-10

    Reptiles and Amphibians of Fairchild Air Force Base, WA C on st ru ct io n E n gi n ee ri n g R es ea rc...online library at http://acwc.sdp.sirsi.net/client/default. ERDC/CERL TR-13-5 May 2013 Reptiles and Amphibians of Fairchild Air Force Base, WA...Washington, DC 20314-1000 ERDC/CERL TR-13-5 ii Abstract Many reptile and amphibian (collectively termed “herpetofauna”) populations are declining at

  13. Count data, detection probabilities, and the demography, dynamics, distribution, and decline of amphibians.

    Science.gov (United States)

    Schmidt, Benedikt R

    2003-08-01

    The evidence for amphibian population declines is based on count data that were not adjusted for detection probabilities. Such data are not reliable even when collected using standard methods. The formula C = Np (where C is a count, N the true parameter value, and p is a detection probability) relates count data to demography, population size, or distributions. With unadjusted count data, one assumes a linear relationship between C and N and that p is constant. These assumptions are unlikely to be met in studies of amphibian populations. Amphibian population data should be based on methods that account for detection probabilities.

  14. No evidence for effects of infection with the amphibian chytrid fungus on populations of yellow-bellied toads.

    Science.gov (United States)

    Wagner, Norman; Neubeck, Claus; Guicking, Daniela; Finke, Lennart; Wittich, Martin; Weising, Kurt; Geske, Christian; Veith, Michael

    2017-02-08

    The parasitic chytrid fungus Batrachochytrium dendrobatidis (Bd) can cause the lethal disease chytridiomycosis in amphibians and therefore may play a role in population declines. The yellow-bellied toad Bombina variegata suffered strong declines throughout western and northwestern parts of its range and is therefore listed as highly endangered for Germany and the federal state of Hesse. Whether chytridiomycosis may play a role in the observed local declines of this strictly protected anuran species has never been tested. We investigated 19 Hessian yellow-bellied toad populations for Bd infection rates, conducted capture-mark-recapture studies in 4 of them over 2 to 3 yr, examined survival histories of recaptured infected individuals, and tested whether multi-locus heterozygosity of individuals as well as expected heterozygosity and different environmental variables of populations affect probabilities of Bd infection. Our results show high prevalence of Bd infection in Hessian yellow-bellied toad populations, but although significant decreases in 2 populations could be observed, no causative link to Bd as the reason for this can be established. Mass mortalities or obvious signs of disease in individuals were not observed. Conversely, we show that growth of Bd-infected populations is possible under favorable habitat conditions and that most infected individuals could be recaptured with improved body indices. Neither genetic diversity nor environmental variables appeared to affect Bd infection probabilities. Hence, genetically diverse amphibian specimens and populations may not automatically be less susceptible for Bd infection.

  15. Emerging Ranaviral Infectious Diseases and Amphibian Decline

    Directory of Open Access Journals (Sweden)

    Jacques Robert

    2010-02-01

    Full Text Available Infectious diseases caused by ranaviruses (RV, family Iridoviridae not only affect wild amphibian populations but also agriculture and international animal trade. Although, the prevalence of RV infections and die offs has markedly increased over the last decade, it is still unclear whether these viruses are direct causal agents of extinction or rather are the resulting (secondary consequences of weakened health of amphibian populations leading to increased susceptibility to viral pathogens. In either case, it is important to understand the critical role of host immune defense in controlling RV infections, pathogenicity, and transmission; this is the focus of this review.

  16. Synergism between UV-B radiation and pathogen magnifies amphibian embryo mortality in nature

    International Nuclear Information System (INIS)

    Kiesecker, J.M.; Blaustein, R.

    1995-01-01

    Previous research has shown that amphibians have differential sensitivity to ultraviolet-B (UV-B) radiation. In some species, ambient levels of UV-B radiation cause embryonic mortality in nature. The detrimental effects of UV-B alone or with other agents may ultimately affect amphibians at the population level. Here, we experimentally demonstrate a synergistic effect between UV-B radiation and a pathogenic fungus in the field that increases the mortality of amphibian embryos compared with either factor alone. Studies investigating single factors for causes of amphibian egg mortality or population declines may not reveal the complex factors involved in declines

  17. Trends in amphibian occupancy in the United States

    Science.gov (United States)

    Adams, Michael J.; Miller, David A.W.; Muths, Erin; Corn, Paul Stephen; Grant, Evan H. Campbell; Bailey, Larissa L.; Fellers, Gary M.; Fisher, Robert N.; Sadinski, Walter J.; Waddle, Hardin; Walls, Susan C.

    2013-01-01

    Though a third of amphibian species worldwide are thought to be imperiled, existing assessments simply categorize extinction risk, providing little information on the rate of population losses. We conducted the first analysis of the rate of change in the probability that amphibians occupy ponds and other comparable habitat features across the United States. We found that overall occupancy by amphibians declined 3.7% annually from 2002 to 2011. Species that are Red-listed by the International Union for Conservation of Nature (IUCN) declined an average of 11.6% annually. All subsets of data examined had a declining trend including species in the IUCN Least Concern category. This analysis suggests that amphibian declines may be more widespread and severe than previously realized.

  18. Trends in amphibian occupancy in the United States.

    Directory of Open Access Journals (Sweden)

    Michael J Adams

    Full Text Available Though a third of amphibian species worldwide are thought to be imperiled, existing assessments simply categorize extinction risk, providing little information on the rate of population losses. We conducted the first analysis of the rate of change in the probability that amphibians occupy ponds and other comparable habitat features across the United States. We found that overall occupancy by amphibians declined 3.7% annually from 2002 to 2011. Species that are Red-listed by the International Union for Conservation of Nature (IUCN declined an average of 11.6% annually. All subsets of data examined had a declining trend including species in the IUCN Least Concern category. This analysis suggests that amphibian declines may be more widespread and severe than previously realized.

  19. What we know and don't know about amphibian declines in the West

    Science.gov (United States)

    Corn, Paul Stephen

    1994-01-01

    The problem of declining amphibian species is thought to be particularly acute in western North America, but there are many gaps in our knowledge. Although several declines have been well-documented, other declines are anecdotal or hypothesized. Most documented declines are of ranid frogs or toads (Bufo). Species from montane habitats and those occurring in California have been best studied. Status of many desert species is unknown. Habitat destruction and introduced predators are the most common threats to amphibian populations. Some declines may represent natural variation in population size. Causes have not been determined for several cases where common species have declined over large areas. There are important considerations for ecosystem management, whether changes in amphibian populations are natural or caused by human activities. Causes for declines must be known so that management can be prescribed (or proscribed) to eliminate or minimize these causes. The natural variability of amphibian population numbers and the complexity of metapopulation structure emphasize the necessity of considering multiple temporal and spatial scales in ecosystem management. The decline of amphibian species throughout the world has received considerable recent attention (e.g., Blaustein and Wake 1990, Griffiths and Beebee 1992, Yoffe 1992). Much of this attention derives from a workshop held in February, 1990 on declining amphibians sponsored by the National Research Council Board (NRC) on Biology in Irvine, California (Barinaga 1990, Borchelt 1990). Because of media attention in the aftermath of this conference, it is a popular perception that amphibian declines are a new phenomenon that herpetologists have been slow to recognize (Griffiths and Beebee 1992, Quammen 1993). However, concern about amphibian populations in the United States dates back over 20 years. Beginning in the 1960s, a large, well-documented decline of northern leopard frogs (Rana pipiens) occurred in the

  20. Amphibians at risk? Susceptibility of terrestrial amphibian life stages to pesticides.

    Science.gov (United States)

    Brühl, Carsten A; Pieper, Silvia; Weber, Brigitte

    2011-11-01

    Current pesticide risk assessment does not specifically consider amphibians. Amphibians in the aquatic environment (aquatic life stages or postmetamorphic aquatic amphibians) and terrestrial living juvenile or adult amphibians are assumed to be covered by the risk assessment for aquatic invertebrates and fish, or mammals and birds, respectively. This procedure has been evaluated as being sufficiently protective regarding the acute risk posed by a number of pesticides to aquatic amphibian life stages (eggs, larvae). However, it is unknown whether the exposure and sensitivity of terrestrial living amphibians are comparable to mammalian and avian exposure and sensitivity. We reviewed the literature on dermal pesticide absorption and toxicity studies for terrestrial life stages of amphibians, focusing on the dermal exposure pathway, that is, through treated soil or direct overspray. In vitro studies demonstrated that cutaneous absorption of chemicals is significant and that chemical percutaneous passage, P (cm/h), is higher in amphibians than in mammals. In vivo, the rapid and substantial uptake of the herbicide atrazine from treated soil by toads (Bufo americanus) has been described. Severe toxic effects on various amphibian species have been reported for field-relevant application rates of different pesticides. In general, exposure and toxicity studies for terrestrial amphibian life stages are scarce, and the reported data indicate the need for further research, especially in light of the global amphibian decline. Copyright © 2011 SETAC.

  1. Amphibian molecular ecology and how it has informed conservation.

    Science.gov (United States)

    McCartney-Melstad, Evan; Shaffer, H Bradley

    2015-10-01

    Molecular ecology has become one of the key tools in the modern conservationist's kit. Here we review three areas where molecular ecology has been applied to amphibian conservation: genes on landscapes, within-population processes, and genes that matter. We summarize relevant analytical methods, recent important studies from the amphibian literature, and conservation implications for each section. Finally, we include five in-depth examples of how molecular ecology has been successfully applied to specific amphibian systems. © 2015 John Wiley & Sons Ltd.

  2. Developments in amphibian captive breeding and reintroduction programs.

    Science.gov (United States)

    Harding, Gemma; Griffiths, Richard A; Pavajeau, Lissette

    2016-04-01

    Captive breeding and reintroduction remain high profile but controversial conservation interventions. It is important to understand how such programs develop and respond to strategic conservation initiatives. We analyzed the contribution to conservation made by amphibian captive breeding and reintroduction since the launch of the International Union for Conservation of Nature (IUCN) Amphibian Conservation Action Plan (ACAP) in 2007. We assembled data on amphibian captive breeding and reintroduction from a variety of sources including the Amphibian Ark database and the IUCN Red List. We also carried out systematic searches of Web of Science, JSTOR, and Google Scholar for relevant literature. Relative to data collected from 1966 to 2006, the number of species involved in captive breeding and reintroduction projects increased by 57% in the 7 years since release of the ACAP. However, there have been relatively few new reintroductions over this period; most programs have focused on securing captive-assurance populations (i.e., species taken into captivity as a precaution against extinctions in the wild) and conservation-related research. There has been a shift to a broader representation of frogs, salamanders, and caecilians within programs and an increasing emphasis on threatened species. There has been a relative increase of species in programs from Central and South America and the Caribbean, where amphibian biodiversity is high. About half of the programs involve zoos and aquaria with a similar proportion represented in specialist facilities run by governmental or nongovernmental agencies. Despite successful reintroduction often being regarded as the ultimate milestone for such programs, the irreversibility of many current threats to amphibians may make this an impractical goal. Instead, research on captive assurance populations may be needed to develop imaginative solutions to enable amphibians to survive alongside current, emerging, and future threats. © 2015

  3. cytogenetic effects in populations of amphibians Rana arvalis living on the radio-contaminated area

    Energy Technology Data Exchange (ETDEWEB)

    Yushkova, E.; Bodnar, I.; Zainullin, V. [Institute of Biology of Komi Scientific Centre of the Ural Branch of the Russian Academy of Sciences (Russian Federation)

    2014-07-01

    of all types of DNA damages in blood cells of amphibians exposed to radioactive impact environment was noted. Thus the reaction of natural populations of amphibians conditional increased levels of cytogenetic damages in their cells is determined the long-term of action by factors of radioactive contamination of the environment. This work was supported by Integration project of the Ural Branch of the Russian Academy of Sciences (No. 12-I-4-2006). Document available in abstract form only. (authors)

  4. The Current and Historical Distribution of Special Status Amphibians at the Livermore Site and Site 300

    Energy Technology Data Exchange (ETDEWEB)

    Hattem, M V; Paterson, L; Woollett, J

    2008-08-20

    65 surveys were completed in 2002 to assess the current distribution of special status amphibians at the Lawrence Livermore National Laboratory's (LLNL) Livermore Site and Site 300. Combined with historical information from previous years, the information presented herein illustrates the dynamic and probable risk that amphibian populations face at both sites. The Livermore Site is developed and in stark contrast to the mostly undeveloped Site 300. Yet both sites have significant issues threatening the long-term sustainability of their respective amphibian populations. Livermore Site amphibians are presented with a suite of challenges inherent of urban interfaces, most predictably the bullfrog (Rana catesbeiana), while Site 300's erosion issues and periodic feral pig (Sus scrofa) infestations reduce and threaten populations. The long-term sustainability of LLNL's special status amphibians will require active management and resource commitment to maintain and restore amphibian habitat at both sites.

  5. Effects of experimental canopy manipulation on amphibian egg deposition

    Science.gov (United States)

    Zachary I. Felix; Yong Wang; Callie J. Schweitzer

    2010-01-01

    Although effects of forest management on amphibians are relatively well studied, few studies have examined how these practices affect egg deposition by adults, which can impact population recruitment. We quantified the effects of 4 canopy tree-retention treatments on amphibian oviposition patterns in clusters of 60-L aquatic mesocosms located in each treatment. We also...

  6. Global amphibian declines: perspectives from the United States and beyond

    Science.gov (United States)

    Densmore, Christine L.; Cipriano, R.C.; Bruckner, A.W.; Shchelkunov, I.S.

    2011-01-01

    Over recent decades, amphibians have experienced population declines, extirpations and species-level extinctions at an alarming rate. Numerous potential etiologies for amphibian declines have been postulated including climate and habitat degradation. Other potential anthropogenic causes including overexploitation and the frequent introductions of invasive predatory species have also been blamed for amphibian declines. Still other underlying factors may include infectious diseases caused by the chytrid fungus Batrachochytrium dendrobatidis, pathogenic viruses (Ranavirus), and other agents. It is nearly certain that more than one etiology is to blame for the majority of the global amphibian declines, and that these causal factors include some combination of climatological or physical habitat destabilization and infectious disease, most notably chytridiomycosis. Scientific research efforts are aimed at elucidating these etiologies on local, regional, and global scales that we might better understand and counteract the driving forces behind amphibian declines. Conservation efforts as outlined in the Amphibian Conservation Action Plan of 2005 are also being made to curtail losses and prevent further extinctions wherever possible.

  7. Amphibian decline: an integrated analysis of multiple stressor effects

    Energy Technology Data Exchange (ETDEWEB)

    Linder, G.; Krest, S.K.; Sparkling, D.W. (eds.)

    2003-07-01

    Environmental effects of stressors on amphibians have received increased attention but little is known about the effects of these stressors on amphibian populations. The workshop addressed this issue. The proceedings contain 15 chapters, two of which mention effects of coal combustion wastes. These are: Chapter 4: Chemical stressors, by J.H. Burkhart, J.R. Bidwell, D.J. Fort, S.R. Sheffield, and Chapter 8E: Anthropogenic activities producing sink habitats for amphibians in the local landscape: a case study of lethal and sublethal effects of coal combustion residues in the aquatic environment by C.L. Rose and W.A. Hopkins.

  8. Non-native fish introductions and the reversibility of amphibian declines in the Sierra Nevada

    Science.gov (United States)

    Roland A. Knapp

    2004-01-01

    Amphibians are declining worldwide for a variety of reasons, including habitat alteration, introduction of non-native species, disease, climate change, and environmental contaminants. Amphibians often play important roles in structuring ecosystems, and, as a result, amphibian population declines or extinctions are likely to affect other trophic levels (Matthews and...

  9. An alternative framework for responding to the amphibian crisis

    Science.gov (United States)

    Muths, Erin L.; Fisher, Robert N.

    2017-01-01

    Volumes of data illustrate the severity of the crisis affecting amphibians, where > 32% of amphibians worldwide are threatened with declining populations. Although there have been isolated victories, the current approach to the issue is unsuccessful. We suggest that a radically different approach, something akin to human emergency response management (i.e. the Incident Command System), is one alternative to addressing the inertia and lack of cohesion in responding to amphibian issues. We acknowledge existing efforts and the useful research that has been conducted, but we suggest that a change is warranted and that the identification of a new amphibian chytrid provides the impetus for such a change. Our goal is to recognize that without a centralized effort we (collectively) are likely to fail in responding to this challenge.

  10. Heart rate variability in healthy population

    International Nuclear Information System (INIS)

    Alamgir, M.; Hussain, M.M.

    2010-01-01

    Background: Heart rate variability has been considered as an indicator of autonomic status. Little work has been done on heart rate variability in normal healthy volunteers. We aimed at evolving the reference values of heart rate variability in our healthy population. Methods: Twenty-four hour holter monitoring of 37 healthy individuals was done using Holter ECG recorder 'Life card CF' from 'Reynolds Medical'. Heart rate variability in both time and frequency domains was analysed with 'Reynolds Medical Pathfinder Digital/700'. Results: The heart rate variability in normal healthy volunteers of our population was found in time domain using standard deviation of R-R intervals (SDNN), standard deviation of average NN intervals (SDANN), and Square root of the mean squared differences of successive NN intervals (RMSSD). Variation in heart rate variability indices was observed between local and foreign volunteers and RMSSD was found significantly increased (p<0.05) in local population. Conclusions: The values of heart rate variability (RMSSD) in healthy Pakistani volunteers were found increased compared to the foreign data reflecting parasympathetic dominance in our population. (author)

  11. Evaluation of episodic acidification and amphibian declines in the Rocky Mountains

    Science.gov (United States)

    Frank A. Vertucci; Paul Stephen Corn

    1996-01-01

    We define criteria for documenting episodic acidification of amphibian breeding habitats and examine whether episodic acidification is responsible for observed declines of amphibian populations in the Rocky Mountains. Anthropogenic episodic acidification, caused by atmospheric deposition of sulfate and nitrate, occurs when the concentration of acid anions increases...

  12. Modeling effects of conservation grassland losses on amphibian habitat

    Science.gov (United States)

    Mushet, David M.; Neau, Jordan L.; Euliss, Ned H.

    2014-01-01

    Amphibians provide many ecosystem services valued by society. However, populations have declined globally with most declines linked to habitat change. Wetlands and surrounding terrestrial grasslands form habitat for amphibians in the North American Prairie Pothole Region (PPR). Wetland drainage and grassland conversion have destroyed or degraded much amphibian habitat in the PPR. However, conservation grasslands can provide alternate habitat. In the United States, the Conservation Reserve Program (CRP) is the largest program maintaining grasslands on agricultural lands. We used an ecosystem services model (InVEST) parameterized for the PPR to quantify amphibian habitat over a six-year period (2007–2012). We then quantified changes in availability of amphibian habitat under various land-cover scenarios representing incremental losses (10%, 25%, 50%, 75%, and 100%) of CRP grasslands from 2012 levels. The area of optimal amphibian habitat in the four PPR ecoregions modeled (i.e., Northern Glaciated Plains, Northwestern Glaciated Plains, Lake Agassiz Plain, Des Moines Lobe) declined by approximately 22%, from 3.8 million ha in 2007 to 2.9 million ha in 2012. These losses were driven by the conversion of CRP grasslands to croplands, primarily for corn and soybean production. Our modeling identified an additional 0.8 million ha (26%) of optimal amphibian habitat that would be lost if remaining CRP lands are returned to crop production. An economic climate favoring commodity production over conservation has resulted in substantial losses of amphibian habitat across the PPR that will likely continue into the future. Other regions of the world face similar challenges to maintaining amphibian habitats.

  13. The Maryland Amphibian and Reptile Atlas: A Volunteer-Based Distributional Survey

    Directory of Open Access Journals (Sweden)

    Heather R. Cunningham

    2012-01-01

    Full Text Available Declines of amphibian and reptile populations are well documented. Yet a lack of understanding of their distribution may hinder conservation planning for these species. The Maryland Amphibian and Reptile Atlas project (MARA was launched in 2010. This five-year, citizen science project will document the distribution of the 93 amphibian and reptile species in Maryland. During the 2010 and 2011 field seasons, 488 registered MARA volunteers collected 13,919 occurrence records that document 85 of Maryland's amphibian and reptile species, including 19 frog, 20 salamander, five lizard, 25 snake, and 16 turtle species. Thirteen of these species are of conservation concern in Maryland. The MARA will establish a baseline by which future changes in the distribution of populations of native herpetofauna can be assessed as well as provide information for immediate management actions for rare and threatened species. As a citizen science project it has the added benefit of educating citizens about native amphibian and reptile diversity and its ecological benefits—an important step in creating an informed society that actively participates in the long-term conservation of Maryland's nature heritage.

  14. Ecopathology of Ranaviruses Infecting Amphibians

    Directory of Open Access Journals (Sweden)

    Andrew Storfer

    2011-11-01

    Full Text Available Ranaviruses are capable of infecting amphibians from at least 14 families and over 70 individual species. Ranaviruses infect multiple cell types, often culminating in organ necrosis and massive hemorrhaging. Subclinical infections have been documented, although their role in ranavirus persistence and emergence remains unclear. Water is an effective transmission medium for ranaviruses, and survival outside the host may be for significant duration. In aquatic communities, amphibians, reptiles and fish may serve as reservoirs. Controlled studies have shown that susceptibility to ranavirus infection and disease varies among amphibian species and developmental stages, and likely is impacted by host-pathogen coevolution, as well as, exogenous environmental factors. Field studies have demonstrated that the likelihood of epizootics is increased in areas of cattle grazing, where aquatic vegetation is sparse and water quality is poor. Translocation of infected amphibians through commercial trade (e.g., food, fish bait, pet industry contributes to the spread of ranaviruses. Such introductions may be of particular concern, as several studies report that ranaviruses isolated from ranaculture, aquaculture, and bait facilities have greater virulence (i.e., ability to cause disease than wild-type isolates. Future investigations should focus on the genetic basis for pathogen virulence and host susceptibility, ecological and anthropogenic mechanisms contributing to emergence, and vaccine development for use in captive populations and species reintroduction programs.

  15. Applied reproductive technologies and genetic resource banking for amphibian conservation.

    Science.gov (United States)

    Kouba, Andrew J; Vance, Carrie K

    2009-01-01

    As amphibian populations continue to decline, both government and non-government organisations are establishing captive assurance colonies to secure populations deemed at risk of extinction if left in the wild. For the most part, little is known about the nutritional ecology, reproductive biology or husbandry needs of the animals placed into captive breeding programs. Because of this lack of knowledge, conservation biologists are currently facing the difficult task of maintaining and reproducing these species. Academic and zoo scientists are beginning to examine different technologies for maintaining the genetic diversity of founder populations brought out of the wild before the animals become extinct from rapidly spreading epizootic diseases. One such technology is genetic resource banking and applied reproductive technologies for species that are difficult to reproduce reliably in captivity. Significant advances have been made in the last decade for amphibian assisted reproduction including the use of exogenous hormones for induction of spermiation and ovulation, in vitro fertilisation, short-term cold storage of gametes and long-term cryopreservation of spermatozoa. These scientific breakthroughs for a select few species will no doubt serve as models for future assisted breeding protocols and the increasing number of amphibians requiring conservation intervention. However, the development of specialised assisted breeding protocols that can be applied to many different families of amphibians will likely require species-specific modifications considering their wide range of reproductive modes. The purpose of this review is to summarise the current state of knowledge in the area of assisted reproduction technologies and gene banking for the conservation of amphibians.

  16. Trouble in the aquatic world: How wildlife professionals are battling amphibian declines

    Science.gov (United States)

    Olson, Deanna H.; Chestnut, Tara E.

    2014-01-01

    A parasitic fungus, similar to the one that caused the extinction of numerous tropical frog and toad species, is killing salamanders in Europe. Scientists first identified the fungus, Batrachochytrium salamandrivorans, in 2013 as the culprit behind the death of fire salamanders (Salamandra salamandra) in the Netherlands (Martel et al. 2013) and are now exploring its potential impact to other species. Although the fungus, which kills the amphibians by infecting their skin, has not yet spread to the United States, researchers believe it’s only a matter of time before it does and, when that happens, the impact on salamander populations could be devastating (Martel et al. 2014).Reports of worldwide declines of amphibians began a quarter of a century ago (Blaustein & Wake 1990). Globally, some amphibian population declines occurred in the late 1950s and early 1960s, and declining trends continued in North America (Houlahan et al. 2000). In the earlier years, population declines were attributed primarily to overharvest due to unregulated supply of species such as the northern leopard frog (Lithobates pipiens) for educational use (Dodd 2013). In later years, however, causes of declines were less evident. In 1989, herpetologists at the First World Congress of Herpetology traded alarming stories of losses across continents and in seemingly protected landscapes, making it clear that amphibian population declines were a “global phenomenon.” In response to these reports, in 1991, the International Union for Conservation of Nature (IUCN) established the Declining Amphibian Populations Task Force to better understand the scale and scope of global amphibian declines. Unfortunately, the absence of long-term monitoring data and targeted studies made it difficult for the task force to compile information.Today, according to AmphibiaWeb.org, there are 7,342 amphibian species in the world — double the number since the first alerts of declines — making the situation

  17. Amphibian monitoring in the Atchafalaya Basin

    Science.gov (United States)

    Waddle, Hardin

    2011-01-01

    Amphibians are a diverse group of animals that includes frogs, toads, and salamanders. They are adapted to living in a variety of habitats, but most require water for at least one life stage. Amphibians have recently become a worldwide conservation concern because of declines and extinctions even in remote protected areas previously thought to be safe from the pressures of habitat loss and degradation. Amphibians are an important part of ecosystem dynamics because they can be quite abundant and serve both as a predator of smaller organisms and as prey to a suite of vertebrate predators. Their permeable skin and aquatic life history also make them useful as indicators of ecosystem health. Since 2002, the U.S. Geological Survey has been studying the frog and toad species inhabiting the Atchafalaya Basin to monitor for population declines and to better understand how the species are potentially affected by disease, environmental contaminants, and climate change.

  18. Do effects of mercury in larval amphibians persist after metamorphosis?

    Science.gov (United States)

    Todd, Brian D; Willson, John D; Bergeron, Christine M; Hopkins, William A

    2012-01-01

    Despite widespread concern about the role of environmental contaminants in global amphibian declines, and evidence that post-metamorphic life stages contribute disproportionately to amphibian population dynamics, most studies in amphibian ecotoxicology focus on larval life stages. Studies that focus solely on early life stages may miss important effects of contaminant exposure, such as latent effects that manifest some time after previous exposure. Moreover, it is often assumed that effects observed in amphibian larvae will persist to affect survival or reproduction later in life. We used terrestrial enclosures to determine whether exposure to mercury (Hg) through maternal transfer and/or larval diet had any adverse effects in post-metamorphic American toads (Bufo americanus). We found a 5% difference in size at metamorphosis that was attributed to maternal Hg exposure persisted for 1 year in the terrestrial environment, resulting in a 7% difference at the conclusion of the study. Although patterns of survival differed among treatments through time, we found no overall difference in survival after 1 year. We also found no evidence of emergent latent effects in the terrestrial toads that could be attributed to earlier exposure. Our results indicate that adverse effects of maternal Hg exposure that were observed in larval amphibians may persist to affect later terrestrial life stages but that no novel adverse effects developed when animals were raised in a semi-natural environment. Moreover, we found no evidence of persistent effects of dietary Hg exposure in larvae, highlighting a need for greater focus on maternal effects in amphibian ecotoxicology. Finally, we suggest an increase in the use of longitudinal studies to better understand contaminant impacts to amphibian populations via effects in both aquatic and terrestrial life stages.

  19. Estimating Herd Immunity to Amphibian Chytridiomycosis in Madagascar Based on the Defensive Function of Amphibian Skin Bacteria

    Directory of Open Access Journals (Sweden)

    Molly C. Bletz

    2017-09-01

    Full Text Available For decades, Amphibians have been globally threatened by the still expanding infectious disease, chytridiomycosis. Madagascar is an amphibian biodiversity hotspot where Batrachochytrium dendrobatidis (Bd has only recently been detected. While no Bd-associated population declines have been reported, the risk of declines is high when invasive virulent lineages become involved. Cutaneous bacteria contribute to host innate immunity by providing defense against pathogens for numerous animals, including amphibians. Little is known, however, about the cutaneous bacterial residents of Malagasy amphibians and the functional capacity they have against Bd. We cultured 3179 skin bacterial isolates from over 90 frog species across Madagascar, identified them via Sanger sequencing of approximately 700 bp of the 16S rRNA gene, and characterized their functional capacity against Bd. A subset of isolates was also tested against multiple Bd genotypes. In addition, we applied the concept of herd immunity to estimate Bd-associated risk for amphibian communities across Madagascar based on bacterial antifungal activity. We found that multiple bacterial isolates (39% of all isolates cultured from the skin of Malagasy frogs were able to inhibit Bd. Mean inhibition was weakly correlated with bacterial phylogeny, and certain taxonomic groups appear to have a high proportion of inhibitory isolates, such as the Enterobacteriaceae, Pseudomonadaceae, and Xanthamonadaceae (84, 80, and 75% respectively. Functional capacity of bacteria against Bd varied among Bd genotypes; however, there were some bacteria that showed broad spectrum inhibition against all tested Bd genotypes, suggesting that these bacteria would be good candidates for probiotic therapies. We estimated Bd-associated risk for sampled amphibian communities based on the concept of herd immunity. Multiple amphibian communities, including those in the amphibian diversity hotspots, Andasibe and Ranomafana, were

  20. Estimating Herd Immunity to Amphibian Chytridiomycosis in Madagascar Based on the Defensive Function of Amphibian Skin Bacteria.

    Science.gov (United States)

    Bletz, Molly C; Myers, Jillian; Woodhams, Douglas C; Rabemananjara, Falitiana C E; Rakotonirina, Angela; Weldon, Che; Edmonds, Devin; Vences, Miguel; Harris, Reid N

    2017-01-01

    For decades, Amphibians have been globally threatened by the still expanding infectious disease, chytridiomycosis. Madagascar is an amphibian biodiversity hotspot where Batrachochytrium dendrobatidis ( Bd ) has only recently been detected. While no Bd -associated population declines have been reported, the risk of declines is high when invasive virulent lineages become involved. Cutaneous bacteria contribute to host innate immunity by providing defense against pathogens for numerous animals, including amphibians. Little is known, however, about the cutaneous bacterial residents of Malagasy amphibians and the functional capacity they have against Bd . We cultured 3179 skin bacterial isolates from over 90 frog species across Madagascar, identified them via Sanger sequencing of approximately 700 bp of the 16S rRNA gene, and characterized their functional capacity against Bd . A subset of isolates was also tested against multiple Bd genotypes. In addition, we applied the concept of herd immunity to estimate Bd -associated risk for amphibian communities across Madagascar based on bacterial antifungal activity. We found that multiple bacterial isolates (39% of all isolates) cultured from the skin of Malagasy frogs were able to inhibit Bd . Mean inhibition was weakly correlated with bacterial phylogeny, and certain taxonomic groups appear to have a high proportion of inhibitory isolates, such as the Enterobacteriaceae, Pseudomonadaceae, and Xanthamonadaceae (84, 80, and 75% respectively). Functional capacity of bacteria against Bd varied among Bd genotypes; however, there were some bacteria that showed broad spectrum inhibition against all tested Bd genotypes, suggesting that these bacteria would be good candidates for probiotic therapies. We estimated Bd -associated risk for sampled amphibian communities based on the concept of herd immunity. Multiple amphibian communities, including those in the amphibian diversity hotspots, Andasibe and Ranomafana, were estimated to be

  1. FACTORS IMPLICATED IN AMPHIBIAN POPULATION DECLINES IN THE UNITED STATES

    Science.gov (United States)

    This study identified the factors responsible for the decline of native amphibians in the U.S. The type of land use, the introduction of exotic animal species, and chemical contamination were identified as the most likely causes of decline.

  2. Quantitative Proteomics of an Amphibian Pathogen, Batrachochytrium dendrobatidis, following Exposure to Thyroid Hormone

    OpenAIRE

    Thekkiniath, Jose; Zabet-Moghaddam, Masoud; Kottapalli, Kameswara Rao; Pasham, Mithun R.; San Francisco, Susan; San Francisco, Michael

    2015-01-01

    Batrachochytrium dendrobatidis (Bd), a chytrid fungus, has increasingly been implicated as a major factor in the worldwide decline of amphibian populations. The fungus causes chytridiomycosis in susceptible species leading to massive die-offs of adult amphibians. Although Bd infects the keratinized mouthparts of tadpoles and negatively affects foraging behavior, these infections are non-lethal. An important morphogen controlling amphibian metamorphosis is thyroid hormone (T3). Tadpoles may be...

  3. Diversity and dynamics of amphibians in floodplain ecosystems of the Samara river

    Directory of Open Access Journals (Sweden)

    O. V. Zhukov

    2015-04-01

    Full Text Available High emphasis is placed on amphibian importance as a buffer system, which has inhibiting effect on technogenic transformation of biogeocoenoses. Issues of the animals’ use in biological restoration, ecological rehabilitation of technogenic landscapes and in bioindication of environmental conditions are covered. Сhange in any component of the ecosystem leads to changing of the whole ecosystem. Anuran amphibians are extremely vulnerable to harmful effects of many factors of natural and anthropogenic origin. That is why, the destruction of forests, draining of wetlands, global climate change, global and local environmental pollution lead to complete disappearance or drastic decrease in numbers of many species of amphibians, reduction and fragmentation of their habitats, increased diversity and overall proportion of morphological anomalies in the natural populations of this group of animals. Recent studies of morphological changes in amphibians are increasingly being used to assess the state of the natural state of their populations and quality of their environment. In the biogeocenoses which are in the conditions of transformation amphibians have a number of advantages relative to their activity, the rate of reproduction, and euribiont character. Practical recommendations on protection and enrichment of the regional herpetofauna are given. The impact of the number and species diversity of amphibians on forest ecosystems of the steppe Dnieperin various conditions is assessed. Parametric entropy factors, the coefficient of biodiversity helped to identify the dominant species of amphibians. Taking into account the influence of predictors, there is the possibility to determine the number and species diversity of amphibians in the conditions of floodplain lime-ash forest. As a result of recording, the following species were caught: Pelobates fuscus (Laurenti, 1768, Rana arvalis Nilsson, 1842, Bufo bufo (Linnaeus, 1758, Bombina bombina (Linnaeus, 1758

  4. Amphibians and plant-protection products: what research and action is needed?

    Science.gov (United States)

    Aldrich, Annette; Junghans, Marion; Aeberli, Caroline; Brühl, Carsten A; Streissl, Franz; Schmidt, Benedikt R

    2016-01-01

    The majority of Swiss amphibians are threatened. There is a range of factors which have been discussed as possible causes for their decline, including plant protection products (PPPs). The influence of PPPs on amphibian populations has not yet been studied to any great extent, neither for active ingredients nor for the wetting agents, breakdown products or tank mixtures. A further topic of discussion was how to better protect amphibians by reducing their exposure to PPPs in agricultural fields. Experts at a workshop concluded that further research is needed.

  5. Sex Reversal in Amphibians.

    Science.gov (United States)

    Flament, Stéphane

    2016-01-01

    Amphibians have been widely used to study developmental biology due to the fact that embryo development takes place independently of the maternal organism and that observations and experimental approaches are easy. Some amphibians like Xenopus became model organisms in this field. In the first part of this article, the differentiation of the gonads in amphibians and the mechanisms governing this process are reviewed. In the second part, the state of the art about sex reversal, which can be induced by steroid hormones in general and by temperature in some species, is presented. Also information about pollutants found in the environment that could interfere with the development of the amphibian reproductive apparatus or with their reproductive physiology is given. Such compounds could play a part in the amphibian decline, since in the wild, many amphibians are endangered species. © 2016 S. Karger AG, Basel.

  6. Low prevalence of chytrid fungus (Batrachochytrium dendrobatidis) in amphibians of U.S

    Science.gov (United States)

    Blake R. Hossack; Michael J. Adams; Evan H. Campbell Grant; Christopher A. Pearl; James B. Bettaso; William J. Barichivich; Winsor H. Lowe; Kimberly True; Joy L. Ware; Paul Stephen Corn

    2010-01-01

    Many declines of amphibian populations have been associated with chytridiomycosis, a disease caused by the aquatic fungus Batrachochytrium dendrobatidis (Bd). Despite the relatively high prevalence of chytridiomycosis in stream amphibians globally, most surveys in North America have focused primarily on wetland-associated species, which are frequently infected. To...

  7. Can myxosporean parasites compromise fish and amphibian reproduction?

    Science.gov (United States)

    Sitjà-Bobadilla, Ariadna

    2009-08-22

    Research into fish and amphibian reproduction has increased exponentially in recent years owing to the expansion of the aquaculture industry, the need to recover fishery populations, the impact of endocrine disruptors on the aquatic environment and the global decline of amphibian populations. This review focuses on a group of parasites, the Myxozoa, that affect fish and amphibian reproduction. Lists of the myxosporeans that specifically infect gonads are provided. Most of these are parasitic of freshwater hosts, and most amphibian cases are reported from testes. Sex specificity and sex reversal are discussed in relation to gonadal parasitism. The immune response of the fish to the infection is described, and the contribution of the immunoprivilege of gonads to host invasion is emphasized. The pathological effect of these parasites can be significant, especially in aquacultured broodstocks, on some occasions, leading to parasitic castration. Although myxosporean parasites are currently not very frequent in gonads, their impact could increase in the future owing to the transactions in the global market. Their easy release into the aquatic environment with spawning could make their spreading even more feasible. In the absence of commercial drugs or vaccines to treat and prevent these infections, there is an urgent need to develop specific, rapid and reliable diagnostic tools to control and manage animal movements. In addition, much effort is still to be made on deciphering the life cycle of these organisms, their invasion strategies and their immune evasion mechanisms.

  8. Sand quarry wetlands provide high-quality habitat for native amphibians

    Directory of Open Access Journals (Sweden)

    M. Sievers

    2017-05-01

    Full Text Available Anthropogenic disturbances to habitats influence the fitness of individual animals, the abundance of their populations, and the composition of their communities. Wetlands in particular are frequently degraded and destroyed, impacting the animals that inhabit these important ecosystems. The creation of wetlands during and following sand extraction processes is inevitable, and thus, sand quarries have the potential to support aquatic animals. To determine how amphibians utilise these wetlands, I conducted nocturnal call surveys at wetlands within the Kables Sands quarry, New South Wales, Australia, and within surrounding reference wetlands, and quantified levels of developmental instability (DI as a proxy for fitness. Whilst quarry and reference wetlands were largely similar in terms of environmental characteristics, quarry wetlands consistently harboured more amphibian species and individuals. Using unsigned asymmetry as a measure of DI, frogs from the quarry sites exhibited significantly lower levels of DI compared to reference wetlands, indicating that quarry wetlands may be comparatively higher quality. Levels of DI within quarry wetlands also compared favourably to data from healthy frog populations extracted from the literature. Further enhancing the suitability of quarry wetlands would require minimal effort, with potentially significant increases in local and regional biodiversity. Documenting species presence and quantifying individual fitness by measuring limb lengths is an economically and logistically feasible method to assess the health of quarry wetlands. Overall, the methods outlined here provide a powerful, yet simple, tool to assess the overall health and suitability of quarry wetlands that could be easily adopted at quarries throughout the world.

  9. Using occupancy models to understand the distribution of an amphibian pathogen, Batrachochytrium dendrobatidis

    Science.gov (United States)

    Adams, Michael J.; Chelgren, Nathan; Reinitz, David M.; Cole, Rebecca A.; Rachowicz, L.J.; Galvan, Stephanie; Mccreary, Brome; Pearl, Christopher A.; Bailey, Larissa L.; Bettaso, Jamie B.; Bull, Evelyn L.; Leu, Matthias

    2010-01-01

    Batrachochytrium dendrobatidis is a fungal pathogen that is receiving attention around the world for its role in amphibian declines. Study of its occurrence patterns is hampered by false negatives: the failure to detect the pathogen when it is present. Occupancy models are a useful but currently underutilized tool for analyzing detection data when the probability of detecting a species is population, was related to amphibian development stage, day of the year, elevation, and human activities. Batrachochytrium dendrobatidis was found throughout our study area but was only estimated to occur in 53.4% of 78 populations of native amphibians and 66.4% of 40 populations of nonnative Rana catesbeiana tested. We found little evidence to support any spatial hypotheses concerning the probability that the pathogen occurs in a population, but did find evidence of some taxonomic variation. We discuss the interpretation of occupancy model parameters, when, unlike a conventional occupancy application, the number of potential samples or observations is finite.

  10. Batrachochytrium dendrobatidis prevalence and haplotypes in domestic and imported pet amphibians in Japan.

    Science.gov (United States)

    Tamukai, Kenichi; Une, Yumi; Tominaga, Atsushi; Suzuki, Kazutaka; Goka, Koichi

    2014-05-13

    The international trade in amphibians is believed to have increased the spread of Batrachochytrium dendrobatidis (Bd), the fungal pathogen responsible for chytridiomycosis, which has caused a rapid decline in amphibian populations worldwide. We surveyed amphibians imported into Japan and those held in captivity for a long period or bred in Japan to clarify the Bd infection status. Samples were taken from 820 individuals of 109 amphibian species between 2008 and 2011 and were analyzed by a nested-PCR assay. Bd prevalence in imported amphibians was 10.3% (58/561), while it was 6.9% (18/259) in those in private collections and commercially bred amphibians in Japan. We identified the genotypes of this fungus using partial DNA sequences of the internal transcribed spacer (ITS) region. Sequencing of PCR products of all 76 Bd-positive samples revealed 11 haplotypes of the Bd ITS region. Haplotype A (DNA Data Bank of Japan accession number AB435211) was found in 90% (52/58) of imported amphibians. The results show that Bd is currently entering Japan via the international trade in exotic amphibians as pets, suggesting that the trade has indeed played a major role in the spread of Bd.

  11. Physical habitat and its alteration: A common ground for exposure of amphibians to environmental stressors

    Science.gov (United States)

    Bishop, Christine A.; Cunnington, David C.; Fellers, Gary M.; Gibbs, James P.; Pauli, Bruce D.; Rothermel, Betsie B.; Linder, Greg L.; Krest, Sherry K.; Sparling, Donald W.

    2003-01-01

    Amphibians as a class of vertebrates have persisted for hundreds of millions of years (Stebbins and Cohen 1995), but they are currently threatened by a variety of stressors, many resulting from human-related alterations of the environment. Most species of amphibians live closely associated with moist environments throughout their life and have evolved specialized adaptations that conserve water and reduce desiccation (Stebbins and Cohen 1995; Henry 2000; Chapter 2A). Amphibians are ectotherms, so their body temperatures fluctuate with the local environment. Latitude, elevation, and habitat affect environmental temperature and have a strong influence on amphibian distributions. Despite these physiological and habitat constraints, the 4750 species of amphibians in the world today have exploited a wide variety of habitats that range from dry deserts to tropical rain forests and from sea level to elevations above 4000 m (McDairmid and Mitchell 2000).The direct loss of suitable habitat has had a profound effect on amphibian populations (Johnson 1992), as it has on nearly all species of wildlife. In the U.S., 53% of wetlands have been lost to human development in the last 200 years (Dahl 1990). Similar loss of wetlands has occurred throughout much of the world, especially in developing countries (Miller 1993). In many regions, deforestation has reduced or eliminated suitable terrestrial habitats, and this may prove to be the largest global threat to amphibian populations (Johnson 1992). Eight thousand years ago, forests covered approximately 40% of the world’s land (6 billion hectares), but by 1997, the world’s forests had been reduced to 3.5 billion hectares, a 42% loss worldwide (CIDA 2001). The effect of habitat loss is generally both obvious and predictable; with increasing restriction of suitable habitat, amphibian populations will probably not survive. The anthropogenic effects on the quality of the habitat that remains are often less obvious.

  12. Climate change and amphibians

    Science.gov (United States)

    Corn, P.S.

    2005-01-01

    Amphibian life histories are exceedingly sensitive to temperature and precipitation, and there is good evidence that recent climate change has already resulted in a shift to breeding earlier in the year for some species. There are also suggestions that the recent increase in the occurrence of El Niño events has caused declines of anurans in Central America and is linked to elevated mortality of amphibian embryos in the northwestern United States. However, evidence linking amphibian declines in Central America to climate relies solely on correlations, and the mechanisms underlying the declines are not understood. Connections between embryo mortality and declines in abundance have not been demonstrated. Analyses of existing data have generally failed to find a link between climate and amphibian declines. It is likely, however, that future climate change will cause further declines of some amphibian species. Reduced soil moisture could reduce prey species and eliminate habitat. Reduced snowfall and increased summer evaporation could have dramatic effects on the duration or occurrence of seasonal wetlands, which are primary habitat for many species of amphibians. Climate change may be a relatively minor cause of current amphibian declines, but it may be the biggest future challenge to the persistence of many species

  13. Climate change and amphibians

    Directory of Open Access Journals (Sweden)

    Corn, P. S.

    2005-01-01

    Full Text Available Amphibian life histories are exceedingly sensitive to temperature and precipitation, and there is good evidence that recent climate change has already resulted in a shift to breeding earlier in the year for some species. There are also suggestions that the recent increase in the occurrence of El Niño events has caused declines of anurans in Central America and is linked to elevated mortality of amphibian embryos in the northwestern United States. However, evidence linking amphibian declines in Central America to climate relies solely on correlations, and the mechanisms underlying the declines are not understood. Connections between embryo mortality and declines in abundance have not been demonstrated. Analyses of existing data have generally failed to find a link between climate and amphibian declines. It is likely, however, that future climate change will cause further declines of some amphibian species. Reduced soil moisture could reduce prey species and eliminate habitat. Reduced snowfall and increased summer evaporation could have dramatic effects on the duration or occurrence of seasonal wetlands, which are primary habitat for many species of amphibians. Climate change may be a relatively minor cause of current amphibian declines, but it may be the biggest future challenge to the persistence of many species

  14. OPTICAL CHARACTERISTICS OF NATURAL WATERS PROTECT AMPHIBIAN POPULATIONS FROM UV-B IN THE US PACIFIC NORTHWEST

    Science.gov (United States)

    Increased exposure to ultraviolet-B (UV-B) radiation has been proposed as a major environmental stressor leading to global amphibian declines. Prior experimental evidence from the US Pacific Northwest (PNW) indicating the acute embryonic sensitivity of at least 4 amphibian specie...

  15. Amphibians of Olympic National Park

    Science.gov (United States)

    ,

    2000-01-01

    Amphibians evolved from fishes about 360 million years ago and were the first vertebrates adapted to life on land. The word amphibian means "double life." It refers to the life history of many amphibians, which spend part of their life in water and part on land. There are three major groups of amphibians: salamanders, frogs, and toads, and caecilians. Salamanders, frogs, and toads can be found in Olympic National Park (ONP), but caecilians live only in tropical regions. Many amphibians are generalist predators, eating almost any prey they can fit into their mouths.

  16. Amphibians of the Simbruini Mountains (Latium, Central Italy

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    Pierangelo Crucitti

    2010-07-01

    Full Text Available Little attention has been paid to the herpetological fauna of the Simbruini Mountains Regional Park, Latium (Central Italy. In this study, we surveyed 50 sites in the course of about ten years of field research, especially during the period 2005-2008. Nine amphibian species, four Caudata and five Anura, 60.0% out of the 15 amphibian species so far observed in Latium, were discovered in the protected area: Salamandra salamandra, Salamandrina perspicillata, Lissotriton vulgaris, Triturus carnifex, Bombina pachypus, Bufo balearicus, Bufo bufo, Rana dalmatina, Rana italica. Physiography of sites has been detailed together with potential threatening patterns. For each species the following topics have been discussed; ecology of sites, altitudinal distribution, phenology, sintopy. Salamandra salamandra and Bombina pachypus are at higher risk. The importance of the maintenance of artificial/natural water bodies for the conservation management of amphibian population of this territory is discussed.

  17. Do hormone-modulating chemicals impact on reproduction and development of wild amphibians?

    Science.gov (United States)

    Orton, Frances; Tyler, Charles R

    2015-11-01

    Globally, amphibians are undergoing a precipitous decline. At the last estimate in 2004, 32% of the approximately 6000 species were threatened with extinction and 43% were experiencing significant declines. These declines have been linked with a wide range of environmental pressures from habitat loss to climate change, disease and pollution. This review evaluates the evidence that endocrine-disrupting contaminants (EDCs) - pollutants that affect hormone systems - are impacting on wild amphibians and contributing to population declines. The review is limited to anurans (frogs and toads) as data for effects of EDCs on wild urodeles (salamanders, newts) or caecilians (limbless amphibians) are extremely limited. Evidence from laboratory studies has shown that a wide range of chemicals have the ability to alter hormone systems and affect reproductive development and function in anurans, but for the most part only at concentrations exceeding those normally found in natural environments. Exceptions can be found for exposures to the herbicide atrazine and polychlorinated biphenyls in leopard frogs (Rana pipiens) and perchlorate in African clawed frogs (Xenopus laevis). These contaminants induce feminising effects on the male gonads (including 'intersex' - oocytes within testes) at concentrations measured in some aquatic environments. The most extensive data for effects of an EDC in wild amphibian populations are for feminising effects of atrazine on male gonad development in regions across the USA. Even where strong evidence has been provided for feminising effects of EDCs, however, the possible impact of these effects on fertility and breeding outcome has not been established, making inference for effects on populations difficult. Laboratory studies have shown that various chemicals, including perchlorate, polychlorinated biphenyls and bromodiphenylethers, also act as endocrine disrupters through interfering with thyroid-dependent processes that are fundamental for

  18. Developmental responses of amphibians to solar and artificial UVB sources: a comparative study

    International Nuclear Information System (INIS)

    Hays, J.B.; Hoffman, P.D.; Pandelova, Iovanna; Coyle, Daniel

    1996-01-01

    Many amphibian species, in widely scattered locations, currently show population declines and/or reductions in range, but other amphibian species show no such declines. There is no known single cause for these declines. Differential sensitivity to UVB radiation among species might be one contributing factor. We have focused on amphibian eggs, potentially the most UVB-sensitive stage, and compared their resistance to UVB components of sunlight with their levels of photolyase, typically the most important enzyme for repair of the major UV photoproducts in DNA, cyclobutane pyrimidine dimers. (Author)

  19. Understanding Amphibian Declines Through Geographic Approaches

    Science.gov (United States)

    Gallant, Alisa

    2006-01-01

    Growing concern over worldwide amphibian declines warrants serious examination. Amphibians are important to the proper functioning of ecosystems and provide many direct benefits to humans in the form of pest and disease control, pharmaceutical compounds, and even food. Amphibians have permeable skin and rely on both aquatic and terrestrial ecosystems during different seasons and stages of their lives. Their association with these ecosystems renders them likely to serve as sensitive indicators of environmental change. While much research on amphibian declines has centered on mysterious causes, or on causes that directly affect humans (global warming, chemical pollution, ultraviolet-B radiation), most declines are the result of habitat loss and habitat alteration. Improving our ability to characterize, model, and monitor the interactions between environmental variables and amphibian habitats is key to addressing amphibian conservation. In 2000, the U.S. Geological Survey (USGS) initiated the Amphibian Research and Monitoring Initiative (ARMI) to address issues surrounding amphibian declines.

  20. Detecting the effects of environmentally relevant concentrations of thyroid hormone disrupting compounds on amphibian development

    NARCIS (Netherlands)

    Gutleb, A.C.

    2006-01-01

    Persistent organic pollutants such as PCBs have been hypothesized to contribute to the observed global decline of amphibian populations. Thyroid hormone (TH) disruption is one of the possible mechanisms for effects of xenobiotics on amphibian development. In addition to the important functions

  1. Rapid increases and time-lagged declines in amphibian occupancy after wildfire.

    Science.gov (United States)

    Hossack, Blake R; Lowe, Winsor H; Corn, Paul Stephen

    2013-02-01

    Climate change is expected to increase the frequency and severity of drought and wildfire. Aquatic and moisture-sensitive species, such as amphibians, may be particularly vulnerable to these modified disturbance regimes because large wildfires often occur during extended droughts and thus may compound environmental threats. However, understanding of the effects of wildfires on amphibians in forests with long fire-return intervals is limited. Numerous stand-replacing wildfires have occurred since 1988 in Glacier National Park (Montana, U.S.A.), where we have conducted long-term monitoring of amphibians. We measured responses of 3 amphibian species to fires of different sizes, severity, and age in a small geographic area with uniform management. We used data from wetlands associated with 6 wildfires that burned between 1988 and 2003 to evaluate whether burn extent and severity and interactions between wildfire and wetland isolation affected the distribution of breeding populations. We measured responses with models that accounted for imperfect detection to estimate occupancy during prefire (0-4 years) and different postfire recovery periods. For the long-toed salamander (Ambystoma macrodactylum) and Columbia spotted frog (Rana luteiventris), occupancy was not affected for 6 years after wildfire. But 7-21 years after wildfire, occupancy for both species decreased ≥ 25% in areas where >50% of the forest within 500 m of wetlands burned. In contrast, occupancy of the boreal toad (Anaxyrus boreas) tripled in the 3 years after low-elevation forests burned. This increase in occupancy was followed by a gradual decline. Our results show that accounting for magnitude of change and time lags is critical to understanding population dynamics of amphibians after large disturbances. Our results also inform understanding of the potential threat of increases in wildfire frequency or severity to amphibians in the region. ©2012 Society for Conservation Biology.

  2. A conceptual model to facilitate amphibian conservation in the northern Great Plains

    Science.gov (United States)

    Mushnet, David M.; Euliss, Ned H.; Stockwell, Craig A.

    2012-01-01

    As pressures on agricultural landscapes to meet worldwide resource needs increase, amphibian populations face numerous threats including habitat destruction, chemical contaminants, disease outbreaks, wetland sedimentation, and synergistic effects of these perturbations. To facilitate conservation planning, we developed a conceptual model depicting elements critical for amphibian conservation in the northern Great Plains. First, we linked upland, wetland, and landscape features to specific ecological attributes. Ecological attributes included adult survival; reproduction and survival to metamorphosis; and successful dispersal and recolonization. Second, we linked ecosystem drivers, ecosystem stressors, and ecological effects of the region to each ecological attribute. Lastly, we summarized information on these ecological attributes and the drivers, stressors, and effects that work in concert to influence the maintenance of viable and genetically diverse amphibian populations in the northern Great Plains. While our focus was on the northern Great Plains, our conceptual model can be tailored to other geographic regions and taxa.

  3. Citation rate and perceived subject bias in the amphibian-decline literature.

    Science.gov (United States)

    Ohmer, Michel E; Bishop, Phillip J

    2011-02-01

    As a result of global declines in amphibian populations, interest in the conservation of amphibians has grown. This growth has been fueled partially by the recent discovery of other potential causes of declines, including chytridiomycosis (the amphibian chytrid, an infectious disease) and climate change. It has been proposed that researchers have shifted their focus to these novel stressors and that other threats to amphibians, such as habitat loss, are not being studied in proportion to their potential effects. We tested the validity of this proposal by reviewing the literature on amphibian declines, categorizing the primary topic of articles within this literature (e.g., habitat loss or UV-B radiation) and comparing citation rates among articles on these topics and impact factors of journals in which the articles were published. From 1990 to 2009, the proportion of papers on habitat loss remained fairly constant, and although the number of papers on chytridiomycosis increased after the disease was described in 1998, the number of published papers on amphibian declines also increased. Nevertheless, papers on chytridiomycosis were more highly cited than papers not on chytridiomycosis and were published in journals with higher impact factors on average, which may indicate this research topic is more popular in the literature. Our results were not consistent with a shift in the research agenda on amphibians. We believe the perception of such a shift has been supported by the higher citation rates of papers on chytridiomycosis. ©2010 Society for Conservation Biology.

  4. Conserving Prairie Pothole Region wetlands and surrounding grasslands: evaluating effects on amphibians

    Science.gov (United States)

    Mushet, David M.; Neau, Jordan L.

    2014-01-01

    The maintenance of viable and genetically diverse populations of amphibians in the Prairie Pothole Region of the United States depends on upland as well as wetland over-wintering and landscape level habitat features.Prairie pothole wetlands provide important amphibian breeding habitat while grasslands surrounding these wetlands provide foraging habitat for adults, overwintering habitat for some species, and important connectivity among breeding wetlands.Grasslands surrounding wetlands were found to be especially important for wood frogs and northern leopard frogs, while croplands dominated habitat utilized by Great Plains toads and Woodhouse’s toads.Habitat suitability mapping highlighted (1) the influence of deep-water overwintering wetlands on suitable habitat for four of five anuran species encountered; (2) the lack of overlap between areas of core habitat for both the northern leopard frog and wood frog compared to the core habitat for both toad species; and (3) the importance of conservation programs in providing grassland components of northern leopard frog and wood frog habitat.Currently, there are approximately 7.2 million acres (2.9 million hectares, ha) of habitat in the PPR identified as suitable for amphibians. WRP and CRP wetland and grassland habitats accounted for approximately 1.9 million acres (0.75 million ha) or 26 percent of this total area.Continued loss of amphibian habitat resulting from an ongoing trend of returning PPR conservation lands to crop production, will likely have significant negative effects on the region’s ability to maintain amphibian biodiversity. Conversely, increases in conservation wetlands and surrounding grasslands on the PPR landscape have great potential to positively influence the region’s amphibian populations.

  5. Monitoring strategy for eight amphibian species in French Guiana, South America.

    Directory of Open Access Journals (Sweden)

    Elodie A Courtois

    Full Text Available Although dramatic amphibian declines have been documented worldwide, only few of such events have been quantitatively documented for the tropical forests of South America. This is due partly to the fact that tropical amphibians are patchily distributed and difficult to detect. We tested three methods often used to monitor population trends in amphibian species in a remote lowland tropical forest of French Guiana. These methods are capture-mark-recapture (CMR, estimation of the number of calling males with repeated counts data and distance sampling, and rates of occupancy inferred by presence/absence data. We monitored eight diurnal, terrestrial amphibian species including five Dendrobatidae and three Bufonidae. We found that CMR, the most precise way of estimating population size, can be used only with two species in high density patches where the recapture rate is high enough. Only for one of the species (Dendrobates tinctorius, a low coefficient of variation (CV = 0.19 can be achieved with 15 to 20 capture events. For dendrobatid species with day-calling males, audio surveys yield a better probability of detection with only 8 audio surveys needed; quantitative estimates can be achieved by computing the number of calling males inferred from audio counts or distance sampling analysis. We therefore suggest that an efficient monitoring protocol for Neotropical amphibian species should include a combination of sighting and audio techniques, and we discuss the need of implementing a large-scale monitoring in order to provide a baseline for comparison with future changes.

  6. Epidemic disease decimates amphibian abundance, species diversity, and evolutionary history in the highlands of central Panama.

    Science.gov (United States)

    Crawford, Andrew J; Lips, Karen R; Bermingham, Eldredge

    2010-08-03

    Amphibian populations around the world are experiencing unprecedented declines attributed to a chytrid fungal pathogen, Batrachochytrium dendrobatidis. Despite the severity of the crisis, quantitative analyses of the effects of the epidemic on amphibian abundance and diversity have been unavailable as a result of the lack of equivalent data collected before and following disease outbreak. We present a community-level assessment combining long-term field surveys and DNA barcode data describing changes in abundance and evolutionary diversity within the amphibian community of El Copé, Panama, following a disease epidemic and mass-mortality event. The epidemic reduced taxonomic, lineage, and phylogenetic diversity similarly. We discovered that 30 species were lost, including five undescribed species, representing 41% of total amphibian lineage diversity in El Copé. These extirpations represented 33% of the evolutionary history of amphibians within the community, and variation in the degree of population loss and decline among species was random with respect to the community phylogeny. Our approach provides a fast, economical, and informative analysis of loss in a community whether measured by species or phylogenetic diversity.

  7. Amphibians Testing Negative for Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans on the Qinghai-Tibetan Plateau, China

    Institute of Scientific and Technical Information of China (English)

    Supen WANG; Wei ZHU; Liqing FAN; Jiaqi LI; Yiming LI

    2017-01-01

    A disease caused by the fungi Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal) is responsible for recent worldwide declines and extinctions of amphibian populations.The Qinghai-Tibetan Plateau (QTP) is aglobal biodiversity hotspot,yet little is known about the prevalence of Bd and Bsal in this region.In this study,we collected 336 non-invasive skin swabs from wild amphibians (including an exotic amphibian species) on the QTP.In addition,to assess the historical prevalence of Bd and Bsal on the QTP,we collected 117 non-invasive skin swabs from museum-archived amphibian samples (from 1964-1982) originating from the QTP.Our results showed all samples to be negative for Bd and Bsal.The government should ban the potentially harmful introduction of non-native amphibian species to the QTP and educate the public about the impacts of releasing exotic amphibians from chytrid-infected areas into native environments of the QTP.

  8. Climate change and amphibians

    OpenAIRE

    Corn, P. S.

    2005-01-01

    Amphibian life histories are exceedingly sensitive to temperature and precipitation, and there is good evidence that recent climate change has already resulted in a shift to breeding earlier in the year for some species. There are also suggestions that the recent increase in the occurrence of El Niño events has caused declines of anurans in Central America and is linked to elevated mortality of amphibian embryos in the northwestern United States. However, evidence linking amphibian declines i...

  9. Amphibian Chytrid Fungus in Madagascar neither Shows Widespread Presence nor Signs of Certain Establishment.

    Science.gov (United States)

    Kolby, Jonathan E; Skerratt, Lee F

    2015-01-01

    The global spread of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) is associated with amphibian mass mortality, population decline, and extinction. Over the past decade, concern has been expressed for the potential introduction of Bd to Madagascar, a global hotspot of amphibian biodiversity. Following years without detection, widespread Bd presence in Madagascar has now been reported (Bletz et al. 2015a), raising international conservation concern. Before reacting to this finding with a significant management response, the accuracy and context of the data warrant cautious review. Re-examination of a 10-year dataset together with results from more recent surveillance (Kolby et al. 2015) does not yet demonstrate widespread Bd presence. Detection of Bd at "positive" locations in Madagascar has been inconsistent for unknown reasons. Whether Bd is established in Madagascar (i.e. populations are self-sustaining) or instead requires continued introduction to persist also remains uncertain. The deployment of emergency conservation rescue initiatives is expected to target areas where the distribution of Bd and the risk of chytridiomycosis endangering amphibians is believed to overlap. Thus, erroneous description of Bd presence would misdirect limited conservation resources. Standardized surveillance and confirmatory surveys are now imperative to reliably characterize the distribution, potential spread, virulence and overall risk of Bd to amphibians in Madagascar.

  10. Amphibian Chytrid Fungus in Madagascar neither Shows Widespread Presence nor Signs of Certain Establishment.

    Directory of Open Access Journals (Sweden)

    Jonathan E Kolby

    Full Text Available The global spread of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd is associated with amphibian mass mortality, population decline, and extinction. Over the past decade, concern has been expressed for the potential introduction of Bd to Madagascar, a global hotspot of amphibian biodiversity. Following years without detection, widespread Bd presence in Madagascar has now been reported (Bletz et al. 2015a, raising international conservation concern. Before reacting to this finding with a significant management response, the accuracy and context of the data warrant cautious review. Re-examination of a 10-year dataset together with results from more recent surveillance (Kolby et al. 2015 does not yet demonstrate widespread Bd presence. Detection of Bd at "positive" locations in Madagascar has been inconsistent for unknown reasons. Whether Bd is established in Madagascar (i.e. populations are self-sustaining or instead requires continued introduction to persist also remains uncertain. The deployment of emergency conservation rescue initiatives is expected to target areas where the distribution of Bd and the risk of chytridiomycosis endangering amphibians is believed to overlap. Thus, erroneous description of Bd presence would misdirect limited conservation resources. Standardized surveillance and confirmatory surveys are now imperative to reliably characterize the distribution, potential spread, virulence and overall risk of Bd to amphibians in Madagascar.

  11. Historical amphibian declines and extinctions in Brazil linked to chytridiomycosis.

    Science.gov (United States)

    Carvalho, Tamilie; Becker, C Guilherme; Toledo, Luís Felipe

    2017-02-08

    The recent increase in emerging fungal diseases is causing unprecedented threats to biodiversity. The origin of spread of the frog-killing fungus Batrachochytrium dendrobatidis ( Bd ) is a matter of continued debate. To date, the historical amphibian declines in Brazil could not be attributed to chytridiomycosis; the high diversity of hosts coupled with the presence of several Bd lineages predating the reported declines raised the hypothesis that a hypervirulent Bd genotype spread from Brazil to other continents causing the recent global amphibian crisis. We tested for a spatio-temporal overlap between Bd and areas of historical amphibian population declines and extinctions in Brazil. A spatio-temporal convergence between Bd and declines would support the hypothesis that Brazilian amphibians were not adapted to Bd prior to the reported declines, thus weakening the hypothesis that Brazil was the global origin of Bd emergence. Alternatively, a lack of spatio-temporal association between Bd and frog declines would indicate an evolution of host resistance in Brazilian frogs predating Bd 's global emergence , further supporting Brazil as the potential origin of the Bd panzootic. Here, we Bd -screened over 30 000 museum-preserved tadpoles collected in Brazil between 1930 and 2015 and overlaid spatio-temporal Bd data with areas of historical amphibian declines. We detected an increase in the proportion of Bd -infected tadpoles during the peak of amphibian declines (1979-1987). We also found that clusters of Bd -positive samples spatio-temporally overlapped with most records of amphibian declines in Brazil's Atlantic Forest. Our findings indicate that Brazil is post epizootic for chytridiomycosis and provide another piece to the puzzle to explain the origin of Bd globally. © 2017 The Author(s).

  12. Historical amphibian declines and extinctions in Brazil linked to chytridiomycosis

    Science.gov (United States)

    Carvalho, Tamilie; Becker, C. Guilherme

    2017-01-01

    The recent increase in emerging fungal diseases is causing unprecedented threats to biodiversity. The origin of spread of the frog-killing fungus Batrachochytrium dendrobatidis (Bd) is a matter of continued debate. To date, the historical amphibian declines in Brazil could not be attributed to chytridiomycosis; the high diversity of hosts coupled with the presence of several Bd lineages predating the reported declines raised the hypothesis that a hypervirulent Bd genotype spread from Brazil to other continents causing the recent global amphibian crisis. We tested for a spatio-temporal overlap between Bd and areas of historical amphibian population declines and extinctions in Brazil. A spatio-temporal convergence between Bd and declines would support the hypothesis that Brazilian amphibians were not adapted to Bd prior to the reported declines, thus weakening the hypothesis that Brazil was the global origin of Bd emergence. Alternatively, a lack of spatio-temporal association between Bd and frog declines would indicate an evolution of host resistance in Brazilian frogs predating Bd's global emergence, further supporting Brazil as the potential origin of the Bd panzootic. Here, we Bd-screened over 30 000 museum-preserved tadpoles collected in Brazil between 1930 and 2015 and overlaid spatio-temporal Bd data with areas of historical amphibian declines. We detected an increase in the proportion of Bd-infected tadpoles during the peak of amphibian declines (1979–1987). We also found that clusters of Bd-positive samples spatio-temporally overlapped with most records of amphibian declines in Brazil's Atlantic Forest. Our findings indicate that Brazil is post epizootic for chytridiomycosis and provide another piece to the puzzle to explain the origin of Bd globally. PMID:28179514

  13. Batrachochytrium salamandrivorans and the risk of a second amphibian pandemic

    Science.gov (United States)

    Yap, Tiffany A.; Nguyen, Natalie T.; Serr, Megan; Shepak, Alex; Vredenburg, Vance

    2017-01-01

    Amphibians are experiencing devastating population declines globally. A major driver is chytridiomycosis, an emerging infectious disease caused by the fungal pathogens Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal). Bdwas described in 1999 and has been linked with declines since the 1970s, while Bsal is a more recently discovered pathogen that was described in 2013. It is hypothesized that Bsaloriginated in Asia and spread via international trade to Europe, where it has been linked to salamander die-offs. Trade in live amphibians thus represents a significant threat to global biodiversity in amphibians. We review the current state of knowledge regarding Bsal and describe the risk of Bsal spread. We discuss regional responses to Bsal and barriers that impede a rapid, coordinated global effort. The discovery of a second deadly emerging chytrid fungal pathogen in amphibians poses an opportunity for scientists, conservationists, and governments to improve global biosecurity and further protect humans and wildlife from a growing number of emerging infectious diseases.

  14. Hydroperiod and cattle use associated with lower recruitment in an r-selected amphibian with a declining population trend in the Klamath Mountains, California

    Science.gov (United States)

    Esther M. Cole; Rosemary Hartman; Malcolm P. North

    2016-01-01

    Recent population declines in amphibians associated with mortality in early life stages highlight the need for a better understanding of the environmental factors related to successful survival to metamorphosis. In our study, we closely examine the relative importance of environmental factors to three stages of recruitment for Cascade frogs (Rana cascadae...

  15. Presence of the amphibian chytrid fungus Batrachochytrium dendrobatidis in native amphibians exported from Madagascar.

    Directory of Open Access Journals (Sweden)

    Jonathan E Kolby

    Full Text Available The emerging infectious disease chytridiomycosis is driven by the spread of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd, a highly virulent pathogen threatening global amphibian biodiversity. Although pandemic in distribution, previous intensive field surveys have failed to detect Bd in Madagascar, a biodiversity hotspot home to hundreds of endemic amphibian species. Due to the presence of Bd in nearby continental Africa and the ecological crisis that can be expected following establishment in Madagascar, enhanced surveillance is imperative. I sampled 565 amphibians commercially exported from Madagascar for the presence of Bd upon importation to the USA, both to assist early detection efforts and demonstrate the conservation potential of wildlife trade disease surveillance. Bd was detected in three animals via quantitative PCR: a single Heterixalus alboguttatus, Heterixalus betsileo, and Scaphiophryne spinosa. This is the first time Bd has been confirmed in amphibians from Madagascar and presents an urgent call to action. Our early identification of pathogen presence prior to widespread infection provides the necessary tools and encouragement to catalyze a swift, targeted response to isolate and eradicate Bd from Madagascar. If implemented before establishment occurs, an otherwise likely catastrophic decline in amphibian biodiversity may be prevented.

  16. Presence of the amphibian chytrid fungus Batrachochytrium dendrobatidis in native amphibians exported from Madagascar.

    Science.gov (United States)

    Kolby, Jonathan E

    2014-01-01

    The emerging infectious disease chytridiomycosis is driven by the spread of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd), a highly virulent pathogen threatening global amphibian biodiversity. Although pandemic in distribution, previous intensive field surveys have failed to detect Bd in Madagascar, a biodiversity hotspot home to hundreds of endemic amphibian species. Due to the presence of Bd in nearby continental Africa and the ecological crisis that can be expected following establishment in Madagascar, enhanced surveillance is imperative. I sampled 565 amphibians commercially exported from Madagascar for the presence of Bd upon importation to the USA, both to assist early detection efforts and demonstrate the conservation potential of wildlife trade disease surveillance. Bd was detected in three animals via quantitative PCR: a single Heterixalus alboguttatus, Heterixalus betsileo, and Scaphiophryne spinosa. This is the first time Bd has been confirmed in amphibians from Madagascar and presents an urgent call to action. Our early identification of pathogen presence prior to widespread infection provides the necessary tools and encouragement to catalyze a swift, targeted response to isolate and eradicate Bd from Madagascar. If implemented before establishment occurs, an otherwise likely catastrophic decline in amphibian biodiversity may be prevented.

  17. Reservoir-host amplification of disease impact in an endangered amphibian.

    Science.gov (United States)

    Scheele, Ben C; Hunter, David A; Brannelly, Laura A; Skerratt, Lee F; Driscoll, Don A

    2017-06-01

    Emerging wildlife pathogens are an increasing threat to biodiversity. One of the most serious wildlife diseases is chytridiomycosis, caused by the fungal pathogen, Batrachochytrium dendrobatidis (Bd), which has been documented in over 500 amphibian species. Amphibians vary greatly in their susceptibility to Bd; some species tolerate infection, whereas others experience rapid mortality. Reservoir hosts-species that carry infection while maintaining high abundance but are rarely killed by disease-can increase extinction risk in highly susceptible, sympatric species. However, whether reservoir hosts amplify Bd in declining amphibian species has not been examined. We investigated the role of reservoir hosts in the decline of the threatened northern corroboree frog (Pseudophryne pengilleyi) in an amphibian community in southeastern Australia. In the laboratory, we characterized the response of a potential reservoir host, the (nondeclining) common eastern froglet (Crinia signifera), to Bd infection. In the field, we conducted frog abundance surveys and Bd sampling for both P. pengilleyi and C. signifera. We built multinomial logistic regression models to test whether Crinia signifera and environmental factors were associated with P. pengilleyi decline. C. signifera was a reservoir host for Bd. In the laboratory, many individuals maintained intense infections (>1000 zoospore equivalents) over 12 weeks without mortality, and 79% of individuals sampled in the wild also carried infections. The presence of C. signifera at a site was strongly associated with increased Bd prevalence in sympatric P. pengilleyi. Consistent with disease amplification by a reservoir host, P. pengilleyi declined at sites with high C. signifera abundance. Our results suggest that when reservoir hosts are present, population declines of susceptible species may continue long after the initial emergence of Bd, highlighting an urgent need to assess extinction risk in remnant populations of other declined

  18. Chemosignals, hormones, and amphibian reproduction.

    Science.gov (United States)

    Woodley, Sarah

    2015-02-01

    This article is part of a Special Issue "Chemosignals and Reproduction". Amphibians are often thought of as relatively simple animals especially when compared to mammals. Yet the chemosignaling systems used by amphibians are varied and complex. Amphibian chemosignals are particularly important in reproduction, in both aquatic and terrestrial environments. Chemosignaling is most evident in salamanders and newts, but increasing evidence indicates that chemical communication facilitates reproduction in frogs and toads as well. Reproductive hormones shape the production, dissemination, detection, and responsiveness to chemosignals. A large variety of chemosignals have been identified, ranging from simple, invariant chemosignals to complex, variable blends of chemosignals. Although some chemosignals elicit straightforward responses, others have relatively subtle effects. Review of amphibian chemosignaling reveals a number of issues to be resolved, including: 1) the significance of the complex, individually variable blends of courtship chemosignals found in some salamanders, 2) the behavioral and/or physiological functions of chemosignals found in anuran "breeding glands", 3) the ligands for amphibian V2Rs, especially V2Rs expressed in the main olfactory epithelium, and 4) the mechanism whereby transdermal delivery of chemosignals influences behavior. To date, only a handful of the more than 7000 species of amphibians has been examined. Further study of amphibians should provide additional insight to the role of chemosignals in reproduction. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Field evidence for leech-borne transmission of amphibian Ichthyophonus sp.

    Science.gov (United States)

    Raffel, Thomas R; Dillard, James R; Hudson, Peter J

    2006-12-01

    Parasites have been implicated in mass mortality events and population declines of amphibians around the world. One pathogen associated with mortality events in North America is an Ichthyophonus sp.-like organism that affects red-spotted newts (Notophthalmus viridescens) and several frog species, yet little is known about the distribution of this pathogen in wild populations or the mechanism of transmission. In an effort to identify factors influencing the distribution and abundance of this pathogen, we measured Ichthyophonus sp. prevalence and a series of factors that could contribute to transmission in 16 newt populations during spring 2004. In contrast to our initial hypotheses of trophic transmission, several lines of evidence suggested a role for the amphibian leech (Placobdella picta) in Ichthyophonus sp. transmission. We propose the mechanistic hypothesis that a leech acquires Ichthyophonus sp. infection when inserting its proboscis into the muscles beneath the skin of infected newts and transmits the infection to other newts in subsequent feeding bouts. We also found effects of host sex, body mass, and breeding condition on Ichthyophonus sp. prevalence and the number of attached leeches. The number of leeches attached to newts was strongly related to the proportion of newt habitat containing emergent vegetation, suggesting that anthropogenic eutrophication might lead to more frequent or severe outbreaks of Ichthyophonus sp. infection in amphibians.

  20. Do pathogens become more virulent as they spread? Evidence from the amphibian declines in Central America.

    Science.gov (United States)

    Phillips, Ben L; Puschendorf, Robert

    2013-09-07

    The virulence of a pathogen can vary strongly through time. While cyclical variation in virulence is regularly observed, directional shifts in virulence are less commonly observed and are typically associated with decreasing virulence of biological control agents through coevolution. It is increasingly appreciated, however, that spatial effects can lead to evolutionary trajectories that differ from standard expectations. One such possibility is that, as a pathogen spreads through a naive host population, its virulence increases on the invasion front. In Central America, there is compelling evidence for the recent spread of pathogenic Batrachochytrium dendrobatidis (Bd) and for its strong impact on amphibian populations. Here, we re-examine data on Bd prevalence and amphibian population decline across 13 sites from southern Mexico through Central America, and show that, in the initial phases of the Bd invasion, amphibian population decline lagged approximately 9 years behind the arrival of the pathogen, but that this lag diminished markedly over time. In total, our analysis suggests an increase in Bd virulence as it spread southwards, a pattern consistent with rapid evolution of increased virulence on Bd's invading front. The impact of Bd on amphibians might therefore be driven by rapid evolution in addition to more proximate environmental drivers.

  1. Effects of amphibian chytrid fungus on individual survival probability in wild boreal toads

    Science.gov (United States)

    Pilliod, D.S.; Muths, E.; Scherer, R. D.; Bartelt, P.E.; Corn, P.S.; Hossack, B.R.; Lambert, B.A.; Mccaffery, R.; Gaughan, C.

    2010-01-01

    Chytridiomycosis is linked to the worldwide decline of amphibians, yet little is known about the demographic effects of the disease. We collected capture-recapture data on three populations of boreal toads (Bufo boreas [Bufo = Anaxyrus]) in the Rocky Mountains (U.S.A.). Two of the populations were infected with chytridiomycosis and one was not. We examined the effect of the presence of amphibian chytrid fungus (Batrachochytrium dendrobatidis [Bd]; the agent of chytridiomycosis) on survival probability and population growth rate. Toads that were infected with Bd had lower average annual survival probability than uninfected individuals at sites where Bd was detected, which suggests chytridiomycosis may reduce survival by 31-42% in wild boreal toads. Toads that were negative for Bd at infected sites had survival probabilities comparable to toads at the uninfected site. Evidence that environmental covariates (particularly cold temperatures during the breeding season) influenced toad survival was weak. The number of individuals in diseased populations declined by 5-7%/year over the 6 years of the study, whereas the uninfected population had comparatively stable population growth. Our data suggest that the presence of Bd in these toad populations is not causing rapid population declines. Rather, chytridiomycosis appears to be functioning as a low-level, chronic disease whereby some infected individuals survive but the overall population effects are still negative. Our results show that some amphibian populations may be coexisting with Bd and highlight the importance of quantitative assessments of survival in diseased animal populations. Journal compilation. ?? 2010 Society for Conservation Biology. No claim to original US government works.

  2. DNA barcoding amphibians and reptiles.

    Science.gov (United States)

    Vences, Miguel; Nagy, Zoltán T; Sonet, Gontran; Verheyen, Erik

    2012-01-01

    Only a few major research programs are currently targeting COI barcoding of amphibians and reptiles (including chelonians and crocodiles), two major groups of tetrapods. Amphibian and reptile species are typically old, strongly divergent, and contain deep conspecific lineages which might lead to problems in species assignment with incomplete reference databases. As far as known, there is no single pair of COI primers that will guarantee a sufficient rate of success across all amphibian and reptile taxa, or within major subclades of amphibians and reptiles, which means that the PCR amplification strategy needs to be adjusted depending on the specific research question. In general, many more amphibian and reptile taxa have been sequenced for 16S rDNA, which for some purposes may be a suitable complementary marker, at least until a more comprehensive COI reference database becomes available. DNA barcoding has successfully been used to identify amphibian larval stages (tadpoles) in species-rich tropical assemblages. Tissue sampling, DNA extraction, and amplification of COI is straightforward in amphibians and reptiles. Single primer pairs are likely to have a failure rate between 5 and 50% if taxa of a wide taxonomic range are targeted; in such cases the use of primer cocktails or subsequent hierarchical usage of different primer pairs is necessary. If the target group is taxonomically limited, many studies have followed a strategy of designing specific primers which then allow an easy and reliable amplification of all samples.

  3. Interactive effects of wildfire, forest management, and isolation on amphibian and parasite abundance

    Science.gov (United States)

    Hossack, Blake R.; Corn, P. Stephen; Winsor H. Lowe,; R. Kenneth Honeycutt,; Sean A. Parks,

    2013-01-01

    Projected increases in wildfire and other climate-driven disturbances will affect populations and communities worldwide, including host–parasite relationships. Research in temperate forests has shown that wildfire can negatively affect amphibians, but this research has occurred primarily outside of managed landscapes where interactions with human disturbances could result in additive or synergistic effects. Furthermore, parasites represent a large component of biodiversity and can affect host fitness and population dynamics, yet they are rarely included in studies of how vertebrate hosts respond to disturbance. To determine how wildfire affects amphibians and their parasites, and whether effects differ between protected and managed landscapes, we compared abundance of two amphibians and two nematodes relative to wildfire extent and severity around wetlands in neighboring protected and managed forests (Montana, USA). Population sizes of adult, male long-toed salamanders (Ambystoma macrodactylum) decreased with increased burn severity, with stronger negative effects on isolated populations and in managed forests. In contrast, breeding population sizes of Columbia spotted frogs (Rana luteiventris) increased with burn extent in both protected and managed protected forests. Path analysis showed that the effects of wildfire on the two species of nematodes were consistent with differences in their life history and transmission strategies and the responses of their hosts. Burn severity indirectly reduced abundance of soil-transmitted Cosmocercoides variabilis through reductions in salamander abundance. Burn severity also directly reduced C. variabilis abundance, possibly though changes in soil conditions. For the aquatically transmitted nematode Gyrinicola batrachiensis, the positive effect of burn extent on density of Columbia spotted frog larvae indirectly increased parasite abundance. Our results show that effects of wildfire on amphibians depend upon burn extent

  4. Using occupancy models to understand the distribution of an amphibian pathogen, Batrachochytrium dendrobatidis

    Science.gov (United States)

    Adams, Michael J.; Chelgren, Nathan; Reinitz, David M.; Cole, Rebecca A.; Rachowicz, L.J.; Galvan, Stephanie; Mccreary, Brome; Pearl, Christopher A.; Bailey, Larissa L.; Bettaso, Jamie B.; Bull, Evelyn L.; Leu, Matthias

    2010-01-01

    Batrachochytrium dendrobatidis is a fungal pathogen that is receiving attention around the world for its role in amphibian declines. Study of its occurrence patterns is hampered by false negatives: the failure to detect the pathogen when it is present. Occupancy models are a useful but currently underutilized tool for analyzing detection data when the probability of detecting a species is <1. We use occupancy models to evaluate hypotheses concerning the occurrence and prevalence of B. dendrobatidis and discuss how this application differs from a conventional occupancy approach. We found that the probability of detecting the pathogen, conditional on presence of the pathogen in the anuran population, was related to amphibian development stage, day of the year, elevation, and human activities. Batrachochytrium dendrobatidis was found throughout our study area but was only estimated to occur in 53.4% of 78 populations of native amphibians and 66.4% of 40 populations of nonnative Rana catesbeiana tested. We found little evidence to support any spatial hypotheses concerning the probability that the pathogen occurs in a population, but did find evidence of some taxonomic variation. We discuss the interpretation of occupancy model parameters, when, unlike a conventional occupancy application, the number of potential samples or observations is finite.

  5. Ichthyophonus sp. (Ichthyophonae, Ichthyophonida) infection in a South American amphibian, the hylid frog Hypsiboas pulchellus.

    Science.gov (United States)

    Borteiro, Claudio; Verdes, José Manuel; Cruz, Juan Carlos; Sabalsagaray, María Jesús; Kolenc, Francisco; Martínez Debat, Claudio; Ubilla, Martín

    2015-04-01

    We report infection by Ichthyophonus sp. in a South American amphibian, the hylid frog Hypsiboas pulchellus in Uruguay. This frog had a large subcutaneous mass over the urostyle and dorsal musculature comprised of parasitic cysts with mild granulomatous inflammation but otherwise appeared healthy.

  6. Habitat split and the global decline of amphibians.

    Science.gov (United States)

    Becker, Carlos Guilherme; Fonseca, Carlos Roberto; Haddad, Célio Fernando Baptista; Batista, Rômulo Fernandes; Prado, Paulo Inácio

    2007-12-14

    The worldwide decline in amphibians has been attributed to several causes, especially habitat loss and disease. We identified a further factor, namely "habitat split"-defined as human-induced disconnection between habitats used by different life history stages of a species-which forces forest-associated amphibians with aquatic larvae to make risky breeding migrations between suitable aquatic and terrestrial habitats. In the Brazilian Atlantic Forest, we found that habitat split negatively affects the richness of species with aquatic larvae but not the richness of species with terrestrial development (the latter can complete their life cycle inside forest remnants). This mechanism helps to explain why species with aquatic larvae have the highest incidence of population decline. These findings reinforce the need for the conservation and restoration of riparian vegetation.

  7. Interventions for reducing extinction risk in chytridiomycosis-threatened amphibians.

    Science.gov (United States)

    Scheele, Ben C; Hunter, David A; Grogan, Laura F; Berger, Lee; Kolby, Jon E; McFadden, Michael S; Marantelli, Gerry; Skerratt, Lee F; Driscoll, Don A

    2014-10-01

    Wildlife diseases pose an increasing threat to biodiversity and are a major management challenge. A striking example of this threat is the emergence of chytridiomycosis. Despite diagnosis of chytridiomycosis as an important driver of global amphibian declines 15 years ago, researchers have yet to devise effective large-scale management responses other than biosecurity measures to mitigate disease spread and the establishment of disease-free captive assurance colonies prior to or during disease outbreaks. We examined the development of management actions that can be implemented after an epidemic in surviving populations. We developed a conceptual framework with clear interventions to guide experimental management and applied research so that further extinctions of amphibian species threatened by chytridiomycosis might be prevented. Within our framework, there are 2 management approaches: reducing Batrachochytrium dendrobatidis (the fungus that causes chytridiomycosis) in the environment or on amphibians and increasing the capacity of populations to persist despite increased mortality from disease. The latter approach emphasizes that mitigation does not necessarily need to focus on reducing disease-associated mortality. We propose promising management actions that can be implemented and tested based on current knowledge and that include habitat manipulation, antifungal treatments, animal translocation, bioaugmentation, head starting, and selection for resistance. Case studies where these strategies are being implemented will demonstrate their potential to save critically endangered species. © 2014 Society for Conservation Biology.

  8. Overcoming challenges to the recovery of declining amphibian populations in the United States

    Science.gov (United States)

    Walls, Susan; Ball, Lianne C.; Barichivich, William J.; Dodd, Kenneth; Enge, Kevin M; Gorman, Thomas A.; O'Donnell, Katherine; Palis, John G; Semlitsch, Raymond D.

    2016-01-01

    The US Endangered Species Act of 1973 (ESA) affords many potential benefits to species threatened with extinction. However, most at-risk amphibians—one of the most imperiled vertebrate groups—remain unlisted under the provisions of the ESA, and many impediments to recovery exist for those species that have been listed. Of the 35 US amphibian species and distinct population segments (“taxa”) listed under the ESA, 40% currently lack a final (completed) recovery plan, 28.6% lack designated critical habitat, and 8.6% lack both. For taxa that have recovery plans, the time between their listing and the development of those plans was from 2 to 29 years, and the time between their listing and the designation of critical habitat ranged from 0 to 14 years. The underlying causes of such delays in protection are complex and constitute obstacles to recovery of imperiled species. We outline a series of strategic actions by which these challenges may be overcome.

  9. Histological evidence of chytridiomycete fungal infection in a free-ranging amphibian, Afrana fuscigula (Anura: Ranidae), in South Africa : short communication

    OpenAIRE

    E.P. Lane; C. Weldon; J. Bingham

    2003-01-01

    The 1st recorded histological evidence of chytridiomycete fungal infection in a free-ranging ranid amphibian in South Africa is presented. Literature on causes of a worldwide decline in amphibian populations is briefly reviewed.

  10. Marginal Bayesian nonparametric model for time to disease arrival of threatened amphibian populations.

    Science.gov (United States)

    Zhou, Haiming; Hanson, Timothy; Knapp, Roland

    2015-12-01

    The global emergence of Batrachochytrium dendrobatidis (Bd) has caused the extinction of hundreds of amphibian species worldwide. It has become increasingly important to be able to precisely predict time to Bd arrival in a population. The data analyzed herein present a unique challenge in terms of modeling because there is a strong spatial component to Bd arrival time and the traditional proportional hazards assumption is grossly violated. To address these concerns, we develop a novel marginal Bayesian nonparametric survival model for spatially correlated right-censored data. This class of models assumes that the logarithm of survival times marginally follow a mixture of normal densities with a linear-dependent Dirichlet process prior as the random mixing measure, and their joint distribution is induced by a Gaussian copula model with a spatial correlation structure. To invert high-dimensional spatial correlation matrices, we adopt a full-scale approximation that can capture both large- and small-scale spatial dependence. An efficient Markov chain Monte Carlo algorithm with delayed rejection is proposed for posterior computation, and an R package spBayesSurv is provided to fit the model. This approach is first evaluated through simulations, then applied to threatened frog populations in Sequoia-Kings Canyon National Park. © 2015, The International Biometric Society.

  11. A novel copro-diagnostic molecular method for qualitative detection and identification of parasitic nematodes in amphibians and reptiles.

    Directory of Open Access Journals (Sweden)

    Lucas G Huggins

    environmental DNA approach mitigates problems associated with microscopic identification and can be applied to detect nematode parasitoses in wild and captive hosts for infection surveillance and maintenance of healthy populations.

  12. A novel copro-diagnostic molecular method for qualitative detection and identification of parasitic nematodes in amphibians and reptiles.

    Science.gov (United States)

    Huggins, Lucas G; Michaels, Christopher J; Cruickshank, Sheena M; Preziosi, Richard F; Else, Kathryn J

    2017-01-01

    approach mitigates problems associated with microscopic identification and can be applied to detect nematode parasitoses in wild and captive hosts for infection surveillance and maintenance of healthy populations.

  13. A frog's-eye view of the landscape : quantifying connectivity for fragmented amphibian populations

    NARCIS (Netherlands)

    Vos, C.C.

    1999-01-01

    The spatial habitat requirements are studied for two amphibian species: the tree frog ( Hyla arborea ) and the moor frog ( Rana arvalis ). Fragmentation, the destruction of suitable habitat, results in small fragments that are separated by

  14. Histological evidence of chytridiomycete fungal infection in a free-ranging amphibian, Afrana fuscigula (Anura: Ranidae, in South Africa : short communication

    Directory of Open Access Journals (Sweden)

    E.P. Lane

    2003-06-01

    Full Text Available The 1st recorded histological evidence of chytridiomycete fungal infection in a free-ranging ranid amphibian in South Africa is presented. Literature on causes of a worldwide decline in amphibian populations is briefly reviewed.

  15. Emerging contaminants and their potential effects on amphibians and reptiles

    Science.gov (United States)

    Serious threats to the health and sustainability of global amphibian populations have been well documented over the last few decades. Encroachment upon and destruction of primary habitat is the most critical threat, but some species have disappeared while their habitat remains. Additional stressor...

  16. Terrestrial pesticide exposure of amphibians: an underestimated cause of global decline?

    Science.gov (United States)

    Brühl, Carsten A; Schmidt, Thomas; Pieper, Silvia; Alscher, Annika

    2013-01-01

    Amphibians, a class of animals in global decline, are present in agricultural landscapes characterized by agrochemical inputs. Effects of pesticides on terrestrial life stages of amphibians such as juvenile and adult frogs, toads and newts are little understood and a specific risk assessment for pesticide exposure, mandatory for other vertebrate groups, is currently not conducted. We studied the effects of seven pesticide products on juvenile European common frogs (Rana temporaria) in an agricultural overspray scenario. Mortality ranged from 100% after one hour to 40% after seven days at the recommended label rate of currently registered products. The demonstrated toxicity is alarming and a large-scale negative effect of terrestrial pesticide exposure on amphibian populations seems likely. Terrestrial pesticide exposure might be underestimated as a driver of their decline calling for more attention in conservation efforts and the risk assessment procedures in place do not protect this vanishing animal group.

  17. Amphibians and reptiles of South Ossetia

    Directory of Open Access Journals (Sweden)

    Boris S. Tuniyev

    2017-05-01

    Full Text Available For the first time we have summarised the results of the study of batraho- and herpetofauna of the Republic of South Ossetia. We present an Annotated List of species as authentically living in the region, as well as ever mentioned for it in literature, field notebooks, museum collections and our own expeditions in South Ossetia. The batrachofauna of the Republic of South Ossetia counts nine species and the herpetofauna 19 species. It provides a complete inventory of all finds (65 localities. A number of confirmed species have been assigned for the first time in scientific literature for the territory of South Ossetia: Emys orbicularis, Darevskia mixta, Natrix megalocephala, Hierophis schmidti, Pelias dinniki, P. kaznakovi. We detected the morphological specificity of the South Ossetia' populations of Darevskia praticola, D. brauneri and D. caucasica. The Assessment of conservation status has been evaluated for all forms of amphibians and reptiles in the region. According to its results, five amphibian species and ten reptile species are recommended for inclusion into the Red Data Book of the Republic of South Ossetia. The central problem of environmental activities in the Region is the lack of a network of different rank protected areas covering all natural zones and altitudinal belts. The South Ossetian State Nature Reserve is the single protected area of South Ossetia, which provides protection only for three endangered species of amphibians and three species of reptiles.

  18. Assessing the Threat of Amphibian Chytrid Fungus in the Albertine Rift: Past, Present and Future

    Science.gov (United States)

    Seimon, Tracie A.; Ayebare, Samuel; Sekisambu, Robert; Muhindo, Emmanuel; Mitamba, Guillain; Greenbaum, Eli; Menegon, Michele; Pupin, Fabio; McAloose, Denise; Ammazzalorso, Alyssa; Meirte, Danny; Lukwago, Wilbur; Behangana, Mathias; Seimon, Anton; Plumptre, Andrew J.

    2015-01-01

    Batrachochytrium dendrobatidis (Bd), the cause of chytridiomycosis, is a pathogenic fungus that is found worldwide and is a major contributor to amphibian declines and extinctions. We report results of a comprehensive effort to assess the distribution and threat of Bd in one of the Earth’s most important biodiversity hotspots, the Albertine Rift in central Africa. In herpetological surveys conducted between 2010 and 2014, 1018 skin swabs from 17 amphibian genera in 39 sites across the Albertine Rift were tested for Bd by PCR. Overall, 19.5% of amphibians tested positive from all sites combined. Skin tissue samples from 163 amphibians were examined histologically; of these two had superficial epidermal intracorneal fungal colonization and lesions consistent with the disease chytridiomycosis. One amphibian was found dead during the surveys, and all others encountered appeared healthy. We found no evidence for Bd-induced mortality events, a finding consistent with other studies. To gain a historical perspective about Bd in the Albertine Rift, skin swabs from 232 museum-archived amphibians collected as voucher specimens from 1925–1994 were tested for Bd. Of these, one sample was positive; an Itombwe River frog (Phrynobatrachus asper) collected in 1950 in the Itombwe highlands. This finding represents the earliest record of Bd in the Democratic Republic of Congo. We modeled the distribution of Bd in the Albertine Rift using MaxEnt software, and trained our model for improved predictability. Our model predicts that Bd is currently widespread across the Albertine Rift, with moderate habitat suitability extending into the lowlands. Under climatic modeling scenarios our model predicts that optimal habitat suitability of Bd will decrease causing a major range contraction of the fungus by 2080. Our baseline data and modeling predictions are important for comparative studies, especially if significant changes in amphibian health status or climactic conditions are

  19. Can we enhance amphibians' habitat restoration in the post-mining areas?

    Science.gov (United States)

    Klimaszewski, Krzysztof; Pacholik, Ewa; Snopek, Adam

    2016-09-01

    The study was aimed to evaluate the selected improvements of nature restoration in a depleted gravel pit. The study site consisted of four water reservoirs of different shapes and sizes, flooded after the gravel extraction ended. Ecological succession monitoring, conducted by the Warsaw University of Life Sciences students associated in the Student Scientific Association of Animal Sciences Faculty since the completion of mining, have focused on amphibians. A twofold approach upheld amphibian species population dynamics, as well as selected habitat elements. The restoration practices dedicated to habitat conditions enhancing have been proved to be definitely effective and useful for similar sites.

  20. Amphibian Engineers in the Southwest Pacific

    Science.gov (United States)

    2017-03-08

    too dangerous. The 1st Engineer Amphibian Brigade was relegated to truck duty in England instead of preparing for the cross-channel invasion.21 Before...and dumps through the swamp.93 91 Office of the Chief Engineer , Amphibian Engineer ...inland, whereas the DUKW (and LVT) could drive direct from ship to dump site. 116 Office of the Chief Engineer , Amphibian Engineer Operations, 320-21

  1. Altered Reproductive Function and Amphibian Declines

    OpenAIRE

    Gallipeau, Sherrie

    2014-01-01

    Agrochemical exposure is one of the factors that contributes to worldwide amphibian declines. Most studies that examine agrochemicals and amphibian declines focus on toxicity. However, declines are more likely caused by the sub-lethal effects of agrochemical exposure. Past emphases on the lethal effects of agrochemical exposure have overshadowed the contribution of decreased recruitment in amphibian declines. Additionally, studies that examine agrochemicals and reproductive function tend to f...

  2. Photo-identification in amphibian studies: a test of I3S Pattern

    Directory of Open Access Journals (Sweden)

    Marco Sannolo

    2016-06-01

    Full Text Available Photo-identification is used for individual recognition of several animal species. It gives the possibility to take photos of large species from a distance or to avoid invasive marking techniques in small animals. For amphibians, the use of non-invasive marking methods is even more relevant in the light of their global decline. Here we use the photo-identification data from a population of Triturus carnifex to validate the photo-identification software I3S Pattern. This recently developed utility has never been applied to amphibians. The software proved to be efficient and accurate for individual recognition for this species. Contrarily to the previous releases of the I3S family, I3S Pattern is particularly suitable for amphibians characterized by a complex individual pattern of large blotches or irregular spots, which are not readily identified by eye.

  3. Adaptive responses to salinity stress across multiple life stages in anuran amphibians.

    Science.gov (United States)

    Albecker, Molly A; McCoy, Michael W

    2017-01-01

    In many regions, freshwater wetlands are increasing in salinity at rates exceeding historic levels. Some freshwater organisms, like amphibians, may be able to adapt and persist in salt-contaminated wetlands by developing salt tolerance. Yet adaptive responses may be more challenging for organisms with complex life histories, because the same environmental stressor can require responses across different ontogenetic stages. Here we investigated responses to salinity in anuran amphibians: a common, freshwater taxon with a complex life cycle. We conducted a meta-analysis to define how the lethality of saltwater exposure changes across multiple life stages, surveyed wetlands in a coastal region experiencing progressive salinization for the presence of anurans, and used common garden experiments to investigate whether chronic salt exposure alters responses in three sequential life stages (reproductive, egg, and tadpole life stages) in Hyla cinerea , a species repeatedly observed in saline wetlands. Meta-analysis revealed differential vulnerability to salt stress across life stages with the egg stage as the most salt-sensitive. Field surveys revealed that 25% of the species known to occur in the focal region were detected in salt-intruded habitats. Remarkably, Hyla cinerea was found in large abundances in multiple wetlands with salinity concentrations 450% higher than the tadpole-stage LC 50 . Common garden experiments showed that coastal (chronically salt exposed) populations of H. cinerea lay more eggs, have higher hatching success, and greater tadpole survival in higher salinities compared to inland (salt naïve) populations. Collectively, our data suggest that some species of anuran amphibians have divergent and adaptive responses to salt exposure across populations and across different life stages. We propose that anuran amphibians may be a novel and amenable natural model system for empirical explorations of adaptive responses to environmental change.

  4. Effects of an infectious fungus, Batrachochytrium dendrobatidis, on amphibian predator-prey interactions.

    Directory of Open Access Journals (Sweden)

    Barbara A Han

    2011-02-01

    Full Text Available The effects of parasites and pathogens on host behaviors may be particularly important in predator-prey contexts, since few animal behaviors are more crucial for ensuring immediate survival than the avoidance of lethal predators in nature. We examined the effects of an emerging fungal pathogen of amphibians, Batrachochytrium dendrobatidis, on anti-predator behaviors of tadpoles of four frog species. We also investigated whether amphibian predators consumed infected prey, and whether B. dendrobatidis caused differences in predation rates among prey in laboratory feeding trials. We found differences in anti-predator behaviors among larvae of four amphibian species, and show that infected tadpoles of one species (Anaxyrus boreas were more active and sought refuge more frequently when exposed to predator chemical cues. Salamander predators consumed infected and uninfected tadpoles of three other prey species at similar rates in feeding trials, and predation risk among prey was unaffected by B. dendrobatidis. Collectively, our results show that even sub-lethal exposure to B. dendrobatidis can alter fundamental anti-predator behaviors in some amphibian prey species, and suggest the unexplored possibility that indiscriminate predation between infected and uninfected prey (i.e., non-selective predation could increase the prevalence of this widely distributed pathogen in amphibian populations. Because one of the most prominent types of predators in many amphibian systems is salamanders, and because salamanders are susceptible to B. dendrobatidis, our work suggests the importance of considering host susceptibility and behavioral changes that could arise from infection in both predators and prey.

  5. Acute toxicity tests and meta-analysis identify gaps in tropical ecotoxicology for amphibians.

    Science.gov (United States)

    Ghose, Sonia L; Donnelly, Maureen A; Kerby, Jacob; Whitfield, Steven M

    2014-09-01

    Amphibian populations are declining worldwide, particularly in tropical regions where amphibian diversity is highest. Pollutants, including agricultural pesticides, have been identified as a potential contributor to decline, yet toxicological studies of tropical amphibians are very rare. The present study assesses toxic effects on amphibians of 10 commonly used commercial pesticides in tropical agriculture using 2 approaches. First, the authors conducted 8-d toxicity assays with formulations of each pesticide using individually reared red-eyed tree frog (Agalychnis callidryas) tadpoles. Second, they conducted a review of available data for the lethal concentration to kill 50% of test animals from the US Environmental Protection Agency's ECOTOX database to allow comparison with their findings. Lethal concentration estimates from the assays ranged over several orders of magnitude. The nematicides terbufos and ethoprophos and the fungicide chlorothalonil were very highly toxic, with evident effects within an order of magnitude of environmental concentrations. Acute toxicity assays and meta-analysis show that nematicides and fungicides are generally more toxic than herbicides yet receive far less research attention than less toxic herbicides. Given that the tropics have a high diversity of amphibians, the findings emphasize the need for research into the effects of commonly used pesticides in tropical countries and should help guide future ecotoxicological research in tropical regions. © 2014 SETAC.

  6. Toward immunogenetic studies of amphibian chytridiomycosis: Linking innate and acquired immunity

    Science.gov (United States)

    Richmond, J.Q.; Savage, Anna E.; Zamudio, Kelly R.; Rosenblum, E.B.

    2009-01-01

    Recent declines in amphibian diversity and abundance have contributed significantly to the global loss of biodiversity. The fungal disease chytridiomycosis is widely considered to be a primary cause of these declines, yet the critical question of why amphibian species differ in susceptibility remains unanswered. Considerable evidence links environmental conditions and interspecific variability of the innate immune system to differential infection responses, but other sources of individual, population, or species-typical variation may also be important. In this article we review the preliminary evidence supporting a role for acquired immune defenses against chytridiomycosis, and advocate for targeted investigation of genes controlling acquired responses, as well as those that functionally bridge the innate and acquired immune systems. Immunogenetic data promise to answer key questions about chytridiomycosis susceptibility and host-pathogen coevolution, and will draw much needed attention to the importance of considering evolutionary processes in amphibian conservation management and practice. ?? 2009 by American Institute of Biological Sciences.

  7. Anthropogenic and ecological drivers of amphibian disease (ranavirosis.

    Directory of Open Access Journals (Sweden)

    Alexandra C North

    Full Text Available Ranaviruses are causing mass amphibian die-offs in North America, Europe and Asia, and have been implicated in the decline of common frog (Rana temporaria populations in the UK. Despite this, we have very little understanding of the environmental drivers of disease occurrence and prevalence. Using a long term (1992-2000 dataset of public reports of amphibian mortalities, we assess a set of potential predictors of the occurrence and prevalence of Ranavirus-consistent common frog mortality events in Britain. We reveal the influence of biotic and abiotic drivers of this disease, with many of these abiotic characteristics being anthropogenic. Whilst controlling for the geographic distribution of mortality events, disease prevalence increases with increasing frog population density, presence of fish and wild newts, increasing pond depth and the use of garden chemicals. The presence of an alternative host reduces prevalence, potentially indicating a dilution effect. Ranavirosis occurrence is associated with the presence of toads, an urban setting and the use of fish care products, providing insight into the causes of emergence of disease. Links between occurrence, prevalence, pond characteristics and garden management practices provides useful management implications for reducing the impacts of Ranavirus in the wild.

  8. Chironomidae bloodworms larvae as aquatic amphibian food.

    Science.gov (United States)

    Fard, Mojdeh Sharifian; Pasmans, Frank; Adriaensen, Connie; Laing, Gijs Du; Janssens, Geert Paul Jules; Martel, An

    2014-01-01

    Different species of chironomids larvae (Diptera: Chironomidae) so-called bloodworms are widely distributed in the sediments of all types of freshwater habitats and considered as an important food source for amphibians. In our study, three species of Chironomidae (Baeotendipes noctivagus, Benthalia dissidens, and Chironomus riparius) were identified in 23 samples of larvae from Belgium, Poland, Russia, and Ukraine provided by a distributor in Belgium. We evaluated the suitability of these samples as amphibian food based on four different aspects: the likelihood of amphibian pathogens spreading, risk of heavy metal accumulation in amphibians, nutritive value, and risk of spreading of zoonotic bacteria (Salmonella, Campylobacter, and ESBL producing Enterobacteriaceae). We found neither zoonotic bacteria nor the amphibian pathogens Ranavirus and Batrachochytrium dendrobatidis in these samples. Our data showed that among the five heavy metals tested (Hg, Cu, Cd, Pb, and Zn), the excess level of Pb in two samples and low content of Zn in four samples implicated potential risk of Pb accumulation and Zn inadequacy. Proximate nutritional analysis revealed that, chironomidae larvae are consistently high in protein but more variable in lipid content. Accordingly, variations in the lipid: protein ratio can affect the amount and pathway of energy supply to the amphibians. Our study indicated although environmentally-collected chironomids larvae may not be vectors of specific pathogens, they can be associated with nutritional imbalances and may also result in Pb bioaccumulation and Zn inadequacy in amphibians. Chironomidae larvae may thus not be recommended as single diet item for amphibians. © 2014 Wiley Periodicals, Inc.

  9. Suitability of amphibians and reptiles for translocation.

    Science.gov (United States)

    Germano, Jennifer M; Bishop, Phillip J

    2009-02-01

    Translocations are important tools in the field of conservation. Despite increased use over the last few decades, the appropriateness of translocations for amphibians and reptiles has been debated widely over the past 20 years. To provide a comprehensive evaluation of the suitability of amphibians and reptiles for translocation, we reviewed the results of amphibian and reptile translocation projects published between 1991 and 2006. The success rate of amphibian and reptile translocations reported over this period was twice that reported in an earlier review in 1991. Success and failure rates were independent of the taxonomic class (Amphibia or Reptilia) released. Reptile translocations driven by human-wildlife conflict mitigation had a higher failure rate than those motivated by conservation, and more recent projects of reptile translocations had unknown outcomes. The outcomes of amphibian translocations were significantly related to the number of animals released, with projects releasing over 1000 individuals being most successful. The most common reported causes of translocation failure were homing and migration of introduced individuals out of release sites and poor habitat. The increased success of amphibian and reptile translocations reviewed in this study compared with the 1991 review is encouraging for future conservation projects. Nevertheless, more preparation, monitoring, reporting of results, and experimental testing of techniques and reintroduction questions need to occur to improve translocations of amphibians and reptiles as a whole.

  10. Epidemic disease decimates amphibian abundance, species diversity, and evolutionary history in the highlands of central Panama

    OpenAIRE

    Crawford, Andrew J.; Lips, Karen R.; Bermingham, Eldredge

    2010-01-01

    Amphibian populations around the world are experiencing unprecedented declines attributed to a chytrid fungal pathogen, Batrachochytrium dendrobatidis. Despite the severity of the crisis, quantitative analyses of the effects of the epidemic on amphibian abundance and diversity have been unavailable as a result of the lack of equivalent data collected before and following disease outbreak. We present a community-level assessment combining long-term field surveys and DNA barcode data describing...

  11. Additive threats from pathogens, climate and land-use change for global amphibian diversity

    DEFF Research Database (Denmark)

    Hof, Christian; Bastos Araujo, Miguel; Jetz, Walter

    2011-01-01

    Amphibian population declines far exceed those of other vertebrate groups, with 30% of all species listed as threatened by the International Union for Conservation of Nature. The causes of these declines are a matter of continued research, but probably include climate change, land-use change...... to be found in Africa, parts of northern South America and the Andes. Regions with the highest projected impact of land-use and climate change coincide, but there is little spatial overlap with regions highly threatened by the fungal disease. Overall, the areas harbouring the richest amphibian faunas...... and spread of the pathogenic fungal disease chytridiomycosis. Here we assess the spatial distribution and interactions of these primary threats in relation to the global distribution of amphibian species. We show that the greatest proportions of species negatively affected by climate change are projected...

  12. Large-scale recovery of an endangered amphibian despite ongoing exposure to multiple stressors

    Science.gov (United States)

    Knapp, Roland A.; Fellers, Gary M.; Kleeman, Patrick M.; Miller, David A. W.; Vrendenburg, Vance T.; Rosenblum, Erica Bree; Briggs, Cheryl J.

    2016-01-01

    Amphibians are one of the most threatened animal groups, with 32% of species at risk for extinction. Given this imperiled status, is the disappearance of a large fraction of the Earth’s amphibians inevitable, or are some declining species more resilient than is generally assumed? We address this question in a species that is emblematic of many declining amphibians, the endangered Sierra Nevada yellow-legged frog (Rana sierrae). Based on >7,000 frog surveys conducted across Yosemite National Park over a 20-y period, we show that, after decades of decline and despite ongoing exposure to multiple stressors, including introduced fish, the recently emerged disease chytridiomycosis, and pesticides, R. sierrae abundance increased sevenfold during the study and at a rate of 11% per year. These increases occurred in hundreds of populations throughout Yosemite, providing a rare example of amphibian recovery at an ecologically relevant spatial scale. Results from a laboratory experiment indicate that these increases may be in part because of reduced frog susceptibility to chytridiomycosis. The disappearance of nonnative fish from numerous water bodies after cessation of stocking also contributed to the recovery. The large-scale increases in R. sierrae abundance that we document suggest that, when habitats are relatively intact and stressors are reduced in their importance by active management or species’ adaptive responses, declines of some amphibians may be partially reversible, at least at a regional scale. Other studies conducted over similarly large temporal and spatial scales are critically needed to provide insight and generality about the reversibility of amphibian declines at a global scale.

  13. Amphibian decline and extinction: what we know and what we need to learn.

    Science.gov (United States)

    Collins, James P

    2010-11-01

    For over 350 million yr, thousands of amphibian species have lived on Earth. Since the 1980s, amphibians have been disappearing at an alarming rate, in many cases quite suddenly. What is causing these declines and extinctions? In the modern era (post 1500) there are 6 leading causes of biodiversity loss in general, and all of these acting alone or together are responsible for modern amphibian declines: commercial use; introduced/exotic species that compete with, prey on, and parasitize native frogs and salamanders; land use change; contaminants; climate change; and infectious disease. The first 3 causes are historical in the sense that they have been operating for hundreds of years, although the rate of change due to each accelerated greatly after about the mid-20th century. Contaminants, climate change, and emerging infectious diseases are modern causes suspected of being responsible for the so-called 'enigmatic decline' of amphibians in protected areas. Introduced/exotic pathogens, land use change, and infectious disease are the 3 causes with a clear role in amphibian decline as well as extinction; thus far, the other 3 causes are only implicated in decline and not extinction. The present work is a review of the 6 causes with a focus on pathogens and suggested areas where new research is needed. Batrachochytrium dendrobatidis (Bd) is a chytrid fungus that is an emerging infectious disease causing amphibian population decline and species extinction. Historically, pathogens have not been seen as a major cause of extinction, but Bd is an exception, which is why it is such an interesting, important pathogen to understand. The late 20th and early 21st century global biodiversity loss is characterized as a sixth extinction event. Amphibians are a striking example of these losses as they disappear at a rate that greatly exceeds historical levels. Consequently, modern amphibian decline and extinction is a lens through which we can view the larger story of biodiversity

  14. [Jaws of amphibians and reptiles].

    Science.gov (United States)

    Tanimoto, Masahiro

    2005-04-01

    Big jaws of amphibians and reptiles are mainly treated in this article. In amphibians enlarged skulls are for the big jaw in contrast with human's skulls for the brain. For example, famous fossils of Homo diluvii testis are ones of salamanders in fact. In reptiles, mosasaur jaws and teeth and their ecology are introduced for instance.

  15. Biodiversity and Ecology of Amphibians and Reptiles of the Kennedy Space Center: 1998 Close-Out Report to NASA

    Science.gov (United States)

    Sigel, Richard A.

    1999-01-01

    Since 1992, there have been researchers have been studying the population ecology and conservation biology of the amphibians and reptiles of the Kennedy Space Center (KSC) This research is an outgrowth of my Master's work in the late 1970's under Lew Ehrhart at UCF. The primary emphasis of our studies are (1) examination of long-term changes in the abundance of amphibians and reptile populations, (2) occurrence and effects of Upper Respiratory Tract Disease (URTD) in gopher tortoises (Gopherus polyphemus), and (3) ecological studies of selected species.

  16. Amphibians and Reptiles of the state of Nuevo León, Mexico.

    Science.gov (United States)

    Lemos-Espinal, Julio A; Smith, Geoffrey R; Cruz, Alexander

    2016-01-01

    We compiled a check list of the herpetofauna of Nuevo León. We documented 132 species (23 amphibians, 109 reptiles), representing 30 families (11 amphibians, 19 reptiles) and 73 genera (17 amphibians, 56 reptiles). Only two species are endemic to Nuevo León. Nuevo León contains a relatively high richness of lizards in the genus Sceloporus. Overlap in the herpetofauna of Nuevo León and states it borders is fairly extensive. Of 130 native species, 102 are considered species of Least Concern in the IUCN red list, four are listed as Vulnerable, five are listed as Near Threatened, and four are listed as Endangered. According to SEMARNAT, 78 species are not of conservation concern, 25 are subject to Special Protection, 27 are Threatened, and none are listed as in Danger of Extinction. Given current threats to the herpetofauna, additional efforts to understand the ecology and status of populations in Nuevo León are needed.

  17. Species-specific chitin-binding module 18 expansion in the amphibian pathogen Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Abramyan, John; Stajich, Jason E

    2012-01-01

    Batrachochytrium dendrobatidis is the causative agent of chytridiomycosis, which is considered one of the driving forces behind the worldwide decline in populations of amphibians. As a member of the phylum Chytridiomycota, B. dendrobatidis has diverged significantly to emerge as the only pathogen of adult vertebrates. Such shifts in lifestyle are generally accompanied by various degrees of genomic modifications, yet neither its mode of pathogenicity nor any factors associated with it have ever been identified. Presented here is the identification and characterization of a unique expansion of the carbohydrate-binding module family 18 (CBM18), specific to B. dendrobatidis. CBM (chitin-binding module) expansions have been likened to the evolution of pathogenicity in a variety of fungus species, making this expanded group a prime candidate for the identification of potential pathogenicity factors. Furthermore, the CBM18 expansions are confined to three categories of genes, each having been previously implicated in host-pathogen interactions. These correlations highlight this specific domain expansion as a potential key player in the mode of pathogenicity in this unique fungus. The expansion of CBM18 in B. dendrobatidis is exceptional in its size and diversity compared to other pathogenic species of fungi, making this genomic feature unique in an evolutionary context as well as in pathogenicity. Amphibian populations are declining worldwide at an unprecedented rate. Although various factors are thought to contribute to this phenomenon, chytridiomycosis has been identified as one of the leading causes. This deadly fungal disease is cause by Batrachochytrium dendrobatidis, a chytrid fungus species unique in its pathogenicity and, furthermore, its specificity to amphibians. Despite more than two decades of research, the biology of this fungus species and its deadly interaction with amphibians had been notoriously difficult to unravel. Due to the alarming rate of worldwide

  18. The North American Amphibian Monitoring Program. [abstract

    Science.gov (United States)

    Griffin, J.

    1998-01-01

    The North American Amphibian Monitoring Program has been under development for the past three years. The monitoring strategy for NAAMP has five main prongs: terrestrial salamander surveys, calling surveys, aquatic surveys, western surveys, and atlassing. Of these five, calling surveys were selected as one of the first implementation priorities due to their friendliness to volunteers of varying knowledge levels, relative low cost, and the fact that several groups had already pioneered the techniques involved. While some states and provinces had implemented calling surveys prior to NAAMP, like WI and IL, most states and provinces had little or no history of state/provincewide amphibian monitoring. Thus, the majority of calling survey programs were initiated in the past two years. To assess the progress of this pilot phase, a program review was conducted on the status of the NAAMP calling survey program, and the results of that review will be presented at the meeting. Topics to be discussed include: who is doing what where, extent of route coverage, the continuing random route discussions, quality assurance, strengths and weaknesses of calling surveys, reliability of data, and directions for the future. In addition, a brief overview of the DISPro project will be included. DISPro is a new amphibian monitoring program in National Parks, funded by the Demonstration of Intensive Sites Program (DISPro) through the EPA and NPS. It will begin this year at Big Bend and Shenandoah National Parks. The purpose of the DISPro Amphibian Project will be to investigate relationships between environmental factors and stressors and the distribution, abundance, and health of amphibians in these National Parks. At each Park, amphibian long-term monitoring protocols will be tested, distributions and abundance of amphibians will be mapped, and field research experiments will be conducted to examine stressor effects on amphibians (e.g., ultraviolet radiation, contaminants, acidification).

  19. Extinction debt as a driver of amphibian declines: An example with imperiled flatwoods salamanders

    Science.gov (United States)

    Semiltsch, Raymond D; Walls, Susan; Barichivich, William J.; O'Donnell, Katherine

    2017-01-01

    A comprehensive view of population declines and their underlying causes is necessary to reverse species loss. Historically, in many cases, a narrow view may have allowed species declines to continue, virtually undetected, for long periods of time (perhaps even decades). We suggest that extinction debt is likely responsible for numerous (perhaps most) amphibian declines and that this perspective should be incorporated into the structure of amphibian research and management. Extinction debt, originally proposed to explain changes in species richness following environmental disturbance, also may refer to the proportion of populations of an individual species that is expected to eventually be lost because of habitat change. A conservation framework to address extinction debt focuses research on threats at the individual, population, and metapopulation levels. This approach will help enhance, restore, and protect specific processes and habitats at the proper scale by directing management to the most vulnerable level and stage of a species. We illustrate this approach using Flatwoods Salamanders, Ambystoma cingulatumand Ambystoma bishopi, which occurred historically throughout the Coastal Plain of the southeastern United States but have experienced a greater than 85% loss of populations in recent years. Reversal of these losses is possible only if conservation and recovery efforts encompass individual, population, and metapopulation levels. We illustrate our framework by outlining actions that could be taken at each of these levels to help guide conservation and management of amphibians with complex life cycles and provide options for how to prioritize conservation actions in the face of logistical and budgetary shortfalls.

  20. Validity of fish, birds and mammals as surrogates for amphibians and reptiles in pesticide toxicity assessment.

    Science.gov (United States)

    Ortiz-Santaliestra, Manuel E; Maia, Joao P; Egea-Serrano, Andrés; Lopes, Isabel

    2018-02-28

    Amphibians and reptiles are the two most endangered groups of vertebrates. Environmental pollution by pesticides is recognised as one of the major factors threatening populations of these groups. However, the effects of pesticides on amphibians and reptiles have been studied for few substances, which is partly related to the fact that these animals are not included in the mandatory toxicity testing conducted as part of environmental risk assessments of pesticides. Whether risks of pesticides to amphibians and reptiles are addressed by surrogate taxa used in risk assessment is currently under debate. In order to develop a scientifically sound and robust risk assessment scheme, information needs to be gathered to examine whether fish, birds and mammals are valid surrogates for amphibians and reptiles. We updated a systematic review of scientific literature that was recently published compiling toxicity data on amphibians and reptiles. The outcome of this review was analysed with the purposes to (1) compare endpoints from amphibians and reptiles with the available information from fish, birds and mammals, and (2) develop species sensitivity distributions (SSDs) for those substances tested in at least six amphibian species (no substances were found tested in at least six reptile species) to identify a candidate amphibian model species to be used as surrogate in risk assessment. A positive correlation was found between toxicity recorded on fish and amphibians, the former revealing, in general, to be more sensitive than the latter to waterborne pollutants. In the terrestrial environment, although birds and mammals were more sensitive than amphibians and reptiles to at least 60% of tested substances, just a few weak significant correlations were observed. As a general rule, homoeothermic vertebrates are not good surrogates for reptiles and terrestrial amphibians in pesticide risk assessment. However, some chemical-dependent trends were detected, with pyrethroids and

  1. Effectiveness of amphibians as biodiversity surrogates in pond conservation.

    Science.gov (United States)

    Ilg, Christiane; Oertli, Beat

    2017-04-01

    Amphibian decline has led to worldwide conservation efforts, including the identification and designation of sites for their protection. These sites could also play an important role in the conservation of other freshwater taxa. In 89 ponds in Switzerland, we assessed the effectiveness of amphibians as a surrogate for 4 taxonomic groups that occur in the same freshwater ecosystems as amphibians: dragonflies, aquatic beetles, aquatic gastropods, and aquatic plants. The ponds were all of high value for amphibian conservation. Cross-taxon correlations were tested for species richness and conservation value, and Mantel tests were used to investigate community congruence. Species richness, conservation value, and community composition of amphibians were weakly congruent with these measures for the other taxonomic groups. Paired comparisons for the 5 groups considered showed that for each metric, amphibians had the lowest degree of congruence. Our results imply that site designation for amphibian conservation will not necessarily provide protection for freshwater biodiversity as a whole. To provide adequate protection for freshwater species, we recommend other taxonomic groups be considered in addition to amphibians in the prioritization and site designation process. © 2016 Society for Conservation Biology.

  2. A strategy for monitoring and managing declines in an amphibian community.

    Science.gov (United States)

    Grant, Evan H Campbell; Zipkin, Elise F; Nichols, James D; Campbell, J Patrick

    2013-12-01

    Although many taxa have declined globally, conservation actions are inherently local. Ecosystems degrade even in protected areas, and maintaining natural systems in a desired condition may require active management. Implementing management decisions under uncertainty requires a logical and transparent process to identify objectives, develop management actions, formulate system models to link actions with objectives, monitor to reduce uncertainty and identify system state (i.e., resource condition), and determine an optimal management strategy. We applied one such structured decision-making approach that incorporates these critical elements to inform management of amphibian populations in a protected area managed by the U.S. National Park Service. Climate change is expected to affect amphibian occupancy of wetlands and to increase uncertainty in management decision making. We used the tools of structured decision making to identify short-term management solutions that incorporate our current understanding of the effect of climate change on amphibians, emphasizing how management can be undertaken even with incomplete information. Estrategia para Monitorear y Manejar Disminuciones en una Comunidad de Anfibios. © 2013 Society for Conservation Biology.

  3. Conservation genetics and genomics of amphibians and reptiles.

    Science.gov (United States)

    Shaffer, H Bradley; Gidiş, Müge; McCartney-Melstad, Evan; Neal, Kevin M; Oyamaguchi, Hilton M; Tellez, Marisa; Toffelmier, Erin M

    2015-01-01

    Amphibians and reptiles as a group are often secretive, reach their greatest diversity often in remote tropical regions, and contain some of the most endangered groups of organisms on earth. Particularly in the past decade, genetics and genomics have been instrumental in the conservation biology of these cryptic vertebrates, enabling work ranging from the identification of populations subject to trade and exploitation, to the identification of cryptic lineages harboring critical genetic variation, to the analysis of genes controlling key life history traits. In this review, we highlight some of the most important ways that genetic analyses have brought new insights to the conservation of amphibians and reptiles. Although genomics has only recently emerged as part of this conservation tool kit, several large-scale data sources, including full genomes, expressed sequence tags, and transcriptomes, are providing new opportunities to identify key genes, quantify landscape effects, and manage captive breeding stocks of at-risk species.

  4. Ranking ecological risks of multiple chemical stressors on amphibians.

    Science.gov (United States)

    Fedorenkova, Anastasia; Vonk, J Arie; Lenders, H J Rob; Creemers, Raymond C M; Breure, Anton M; Hendriks, A Jan

    2012-06-01

    Populations of amphibians have been declining worldwide since the late 1960s. Despite global concern, no studies have quantitatively assessed the major causes of this decline. In the present study, species sensitivity distributions (SSDs) were developed to analyze the sensitivity of anurans for ammonium, nitrate, heavy metals (cadmium, copper), pesticides (18 compounds), and acidification (pH) based on laboratory toxicity data. Ecological risk (ER) was calculated as the probability that a measured environmental concentration of a particular stressor in habitats where anurans were observed would exceed the toxic effect concentrations derived from the species sensitivity distributions. The assessment of ER was used to rank the stressors according to their potential risk to anurans based on a case study of Dutch freshwater bodies. The derived ERs revealed that threats to populations of anurans decreased in the sequence of pH, copper, diazinon, ammonium, and endosulfan. Other stressors studied were of minor importance. The method of deriving ER by combining field observation data and laboratory data provides insight into potential threats to species in their habitats and can be used to prioritize stressors, which is necessary to achieve effective management in amphibian conservation. Copyright © 2012 SETAC.

  5. Louisiana ESI: REPTILES (Reptile and Amphibian Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for reptiles and amphibians in coastal Louisiana. Vector polygons represent reptile and amphibian habitats,...

  6. Chytridiomycosis: a global threat to amphibians.

    Science.gov (United States)

    Pereira, P L L; Torres, A M C; Soares, D F M; Hijosa-Valsero, M; Bécares, E

    2013-12-01

    Chytridiomycosis, which is caused by Batrachochytrium dendrobatidis, is an emerging infectious disease of amphibians. The disease is one of the main causes of the global decline in amphibians. The aetiological agent is ubiquitous, with worldwide distribution, and affects a large number of amphibian species in several biomes. In the last decade, scientific research has substantially increased knowledge of the aetiological agent and the associated infection. However, important epidemiological aspects of the environment-mediated interactions between the aetiological agent and the host are not yet clear. The objective of the present review is to describe chytridiomycosis with regard to the major features of the aetiological agent, the host and the environment.

  7. Effect of road deicing salt on the susceptibility of amphibian embryos to infection by water molds.

    Science.gov (United States)

    Karraker, Nancy E; Ruthig, Gregory R

    2009-01-01

    Some causative agents of amphibian declines act synergistically to impact individual amphibians and their populations. In particular, pathogenic water molds (aquatic oomycetes) interact with environmental stressors and increase mortality in amphibian embryos. We documented colonization of eggs of three amphibian species, the wood frog (Rana sylvatica), the green frog (Rana clamitans), and the spotted salamander (Ambystoma maculatum), by water molds in the field and examined the interactive effects of road deicing salt and water molds, two known sources of mortality for amphibian embryos, on two species, R. clamitans and A. maculatum in the laboratory. We found that exposure to water molds did not affect embryonic survivorship in either A. maculatum or R. clamitans, regardless of the concentration of road salt to which their eggs were exposed. Road salt decreased survivorship of A. maculatum, but not R. clamitans, and frequency of malformations increased significantly in both species at the highest salinity concentration. The lack of an effect of water molds on survival of embryos and no interaction between road salt and water molds indicates that observations of colonization of these eggs by water molds in the field probably represent a secondary invasion of unfertilized eggs or of embryos that had died of other causes. Given increasing salinization of freshwater habitats on several continents and the global distribution of water molds, our results suggest that some amphibian species may not be susceptible to the combined effects of these factors, permitting amphibian decline researchers to devote their attention to other potential causes.

  8. Unlocking the story in the swab: A new genotyping assay for the amphibian chytrid fungus Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Byrne, Allison Q; Rothstein, Andrew P; Poorten, Thomas J; Erens, Jesse; Settles, Matthew L; Rosenblum, Erica Bree

    2017-11-01

    One of the most devastating emerging pathogens of wildlife is the chytrid fungus, Batrachochytrium dendrobatidis (Bd), which affects hundreds of amphibian species around the world. Genomic data from pure Bd cultures have advanced our understanding of Bd phylogenetics, genomic architecture and mechanisms of virulence. However, pure cultures are laborious to obtain and whole-genome sequencing is comparatively expensive, so relatively few isolates have been genetically characterized. Thus, we still know little about the genetic diversity of Bd in natural systems. The most common noninvasive method of sampling Bd from natural populations is to swab amphibian skin. Hundreds of thousands of swabs have been collected from amphibians around the world, but Bd DNA collected via swabs is often low in quality and/or quantity. In this study, we developed a custom Bd genotyping assay using the Fluidigm Access Array platform to amplify 192 carefully selected regions of the Bd genome. We obtained robust sequence data for pure Bd cultures and field-collected skin swabs. This new assay has the power to accurately discriminate among the major Bd clades, recovering the basic tree topology previously revealed using whole-genome data. Additionally, we established a critical value for initial Bd load for swab samples (150 Bd genomic equivalents) above which our assay performs well. By leveraging advances in microfluidic multiplex PCR technology and the globally distributed resource of amphibian swab samples, noninvasive skin swabs can now be used to address critical spatial and temporal questions about Bd and its effects on declining amphibian populations. © 2017 John Wiley & Sons Ltd.

  9. Modeling habitat split: landscape and life history traits determine amphibian extinction thresholds.

    Directory of Open Access Journals (Sweden)

    Carlos Roberto Fonseca

    Full Text Available Habitat split is a major force behind the worldwide decline of amphibian populations, causing community change in richness and species composition. In fragmented landscapes, natural remnants, the terrestrial habitat of the adults, are frequently separated from streams, the aquatic habitat of the larvae. An important question is how this landscape configuration affects population levels and if it can drive species to extinction locally. Here, we put forward the first theoretical model on habitat split which is particularly concerned on how split distance - the distance between the two required habitats - affects population size and persistence in isolated fragments. Our diffusive model shows that habitat split alone is able to generate extinction thresholds. Fragments occurring between the aquatic habitat and a given critical split distance are expected to hold viable populations, while fragments located farther away are expected to be unoccupied. Species with higher reproductive success and higher diffusion rate of post-metamorphic youngs are expected to have farther critical split distances. Furthermore, the model indicates that negative effects of habitat split are poorly compensated by positive effects of fragment size. The habitat split model improves our understanding about spatially structured populations and has relevant implications for landscape design for conservation. It puts on a firm theoretical basis the relation between habitat split and the decline of amphibian populations.

  10. Modeling habitat split: landscape and life history traits determine amphibian extinction thresholds.

    Science.gov (United States)

    Fonseca, Carlos Roberto; Coutinho, Renato M; Azevedo, Franciane; Berbert, Juliana M; Corso, Gilberto; Kraenkel, Roberto A

    2013-01-01

    Habitat split is a major force behind the worldwide decline of amphibian populations, causing community change in richness and species composition. In fragmented landscapes, natural remnants, the terrestrial habitat of the adults, are frequently separated from streams, the aquatic habitat of the larvae. An important question is how this landscape configuration affects population levels and if it can drive species to extinction locally. Here, we put forward the first theoretical model on habitat split which is particularly concerned on how split distance - the distance between the two required habitats - affects population size and persistence in isolated fragments. Our diffusive model shows that habitat split alone is able to generate extinction thresholds. Fragments occurring between the aquatic habitat and a given critical split distance are expected to hold viable populations, while fragments located farther away are expected to be unoccupied. Species with higher reproductive success and higher diffusion rate of post-metamorphic youngs are expected to have farther critical split distances. Furthermore, the model indicates that negative effects of habitat split are poorly compensated by positive effects of fragment size. The habitat split model improves our understanding about spatially structured populations and has relevant implications for landscape design for conservation. It puts on a firm theoretical basis the relation between habitat split and the decline of amphibian populations.

  11. Amphibians and reptiles of the state of Hidalgo, Mexico

    OpenAIRE

    Lemos-Espinal, Julio; Smith, Geoffrey

    2015-01-01

    We compiled a checklist of the amphibians and reptiles of the state of Hidalgo, Mexico. The herpetofauna of Hidalgo consists of a total of 175 species: 54 amphibians (14 salamanders and 40 anurans); and 121 reptiles (one crocodile, five turtles, 36 lizards, 79 snakes). These taxa represent 32 families (12 amphibian families, 20 reptile families) and 87 genera (24 amphibian genera, 63 reptile genera). Two of these species are non-native species (Hemidactylus frenatus Duméril and Bibron, 1836 a...

  12. Estrogens can disrupt amphibian mating behavior.

    Directory of Open Access Journals (Sweden)

    Frauke Hoffmann

    Full Text Available The main component of classical contraceptives, 17α-ethinylestradiol (EE2, has high estrogenic activity even at environmentally relevant concentrations. Although estrogenic endocrine disrupting compounds are assumed to contribute to the worldwide decline of amphibian populations by adverse effects on sexual differentiation, evidence for EE2 affecting amphibian mating behaviour is lacking. In this study, we demonstrate that EE2 exposure at five different concentrations (0.296 ng/L, 2.96 ng/L, 29.64 ng/L, 2.96 µg/L and 296.4 µg/L can disrupt the mating behavior of adult male Xenopus laevis. EE2 exposure at all concentrations lowered male sexual arousal, indicated by decreased proportions of advertisement calls and increased proportions of the call type rasping, which characterizes a sexually unaroused state of a male. Additionally, EE2 at all tested concentrations affected temporal and spectral parameters of the advertisement calls, respectively. The classical and highly sensitive biomarker vitellogenin, on the other hand, was only induced at concentrations equal or higher than 2.96 µg/L. If kept under control conditions after a 96 h EE2 exposure (2.96 µg/L, alterations of male advertisement calls vanish gradually within 6 weeks and result in a lower sexual attractiveness of EE2 exposed males toward females as demonstrated by female choice experiments. These findings indicate that exposure to environmentally relevant EE2 concentrations can directly disrupt male mate calling behavior of X. laevis and can indirectly affect the mating behavior of females. The results suggest the possibility that EE2 exposure could reduce the reproductive success of EE2 exposed animals and these effects might contribute to the global problem of amphibian decline.

  13. Phylogenetic analysis of algal symbionts associated with four North American amphibian egg masses.

    Science.gov (United States)

    Kim, Eunsoo; Lin, Yuan; Kerney, Ryan; Blumenberg, Lili; Bishop, Cory

    2014-01-01

    Egg masses of the yellow-spotted salamander Ambystoma maculatum form an association with the green alga "Oophila amblystomatis" (Lambert ex Wille), which, in addition to growing within individual egg capsules, has recently been reported to invade embryonic tissues and cells. The binomial O. amblystomatis refers to the algae that occur in A. maculatum egg capsules, but it is unknown whether this population of symbionts constitutes one or several different algal taxa. Moreover, it is unknown whether egg masses across the geographic range of A. maculatum, or other amphibians, associate with one or multiple algal taxa. To address these questions, we conducted a phylogeographic study of algae sampled from egg capsules of A. maculatum, its allopatric congener A. gracile, and two frogs: Lithobates sylvatica and L. aurora. All of these North American amphibians form associations with algae in their egg capsules. We sampled algae from egg capsules of these four amphibians from localities across North America, established representative algal cultures, and amplified and sequenced a region of 18S rDNA for phylogenetic analysis. Our combined analysis shows that symbiotic algae found in egg masses of four North American amphibians are closely related to each other, and form a well-supported clade that also contains three strains of free-living chlamydomonads. We designate this group as the 'Oophila' clade, within which the symbiotic algae are further divided into four distinct subclades. Phylogenies of the host amphibians and their algal symbionts are only partially congruent, suggesting that host-switching and co-speciation both play roles in their associations. We also established conditions for isolating and rearing algal symbionts from amphibian egg capsules, which should facilitate further study of these egg mass specialist algae.

  14. Phylogenetic analysis of algal symbionts associated with four North American amphibian egg masses.

    Directory of Open Access Journals (Sweden)

    Eunsoo Kim

    Full Text Available Egg masses of the yellow-spotted salamander Ambystoma maculatum form an association with the green alga "Oophila amblystomatis" (Lambert ex Wille, which, in addition to growing within individual egg capsules, has recently been reported to invade embryonic tissues and cells. The binomial O. amblystomatis refers to the algae that occur in A. maculatum egg capsules, but it is unknown whether this population of symbionts constitutes one or several different algal taxa. Moreover, it is unknown whether egg masses across the geographic range of A. maculatum, or other amphibians, associate with one or multiple algal taxa. To address these questions, we conducted a phylogeographic study of algae sampled from egg capsules of A. maculatum, its allopatric congener A. gracile, and two frogs: Lithobates sylvatica and L. aurora. All of these North American amphibians form associations with algae in their egg capsules. We sampled algae from egg capsules of these four amphibians from localities across North America, established representative algal cultures, and amplified and sequenced a region of 18S rDNA for phylogenetic analysis. Our combined analysis shows that symbiotic algae found in egg masses of four North American amphibians are closely related to each other, and form a well-supported clade that also contains three strains of free-living chlamydomonads. We designate this group as the 'Oophila' clade, within which the symbiotic algae are further divided into four distinct subclades. Phylogenies of the host amphibians and their algal symbionts are only partially congruent, suggesting that host-switching and co-speciation both play roles in their associations. We also established conditions for isolating and rearing algal symbionts from amphibian egg capsules, which should facilitate further study of these egg mass specialist algae.

  15. Countryside biogeography of Neotropical reptiles and amphibians.

    Science.gov (United States)

    Mendenhall, Chase D; Frishkoff, Luke O; Santos-Barrera, Georgina; Pacheco, Jesús; Mesfun, Eyobed; Mendoza Quijano, Fernando; Ehrlich, Paul R; Ceballos, Gerardo; Daily, Gretchen C; Pringle, Robert M

    2014-04-01

    The future of biodiversity and ecosystem services depends largely on the capacity of human-dominated ecosystems to support them, yet this capacity remains largely unknown. Using the framework of countryside biogeography, and working in the Las Cruces system of Coto Brus, Costa Rica, we assessed reptile and amphibian assemblages within four habitats that typify much of the Neotropics: sun coffee plantations (12 sites), pasture (12 sites), remnant forest elements (12 sites), and a larger, contiguous protected forest (3 sites in one forest). Through analysis of 1678 captures of 67 species, we draw four primary conclusions. First, we found that the majority of reptile (60%) and amphibian (70%) species in this study used an array of habitat types, including coffee plantations and actively grazed pastures. Second, we found that coffee plantations and pastures hosted rich, albeit different and less dense, reptile and amphibian biodiversity relative to the 326-ha Las Cruces Forest Reserve and neighboring forest elements. Third, we found that the small ribbons of "countryside forest elements" weaving through farmland collectively increased the effective size of a 326-ha local forest reserve 16-fold for reptiles and 14-fold for amphibians within our 236-km2 study area. Therefore, countryside forest elements, often too small for most remote sensing techniques to identify, are contributing -95% of the available habitat for forest-dependent reptiles and amphibians in our largely human-dominated study region. Fourth, we found large and pond-reproducing amphibians to prefer human-made habitats, whereas small, stream-reproducing, and directly developing species are more dependent on forest elements. Our investigation demonstrates that tropical farming landscapes can support substantial reptile and amphibian biodiversity. Our approach provides a framework for estimating the conservation value of the complex working landscapes that constitute roughly half of the global land surface

  16. Pentastomiasis and other parasitic zoonoses from reptiles and amphibians.

    Science.gov (United States)

    Pantchev, Nikola; Tappe, Dennis

    2011-01-01

    Reptiles are growing in popularity as pets.The colonization of reptiles and amphibians by parasites and the resulting disease conditions are the most common problems seen in captive animals.This review focuses on pentastomiasis and sparganosis, important parasitic zoonoses of reptiles and amphibians, respectively, and free living-amoebae. Humans are suitable accidental hosts for some pentastomid species (particularly Armillifer and Porocephalus). In geographical areas with special ethnics, such as in West and Central Africa, and East Asia, 8-45% of the human population can be affected. Usually the larvae are coincidentally found during abdominal surgeries. However, fatalities have been described. Extreme caution is necessary when handling infected reptiles. Ocular or cerebral sparganosis is not uncommonly found in humans in East Asia. This disease is caused by spargana, tapeworm larvae (plerocercoids) of Spirometra sp. The infection occurs when uncooked meat from reptiles or amphibians is applied to wounds or eyes and the parasites migrate directly to human tissue, or by consumption of contaminated food or water. As a consequence of the reptile's predatory behaviour, the full spectrum of endo- and ectoparasites from potential prey animals can be found as transiting parasites in the intestinal tract, e. g. Hymenolepis nana, Cryptosporidium (C.) muris, C parvum or Capillaria hepatica. Occasionally, free-living amoebae are also found in reptile faeces (Acanthamoeba, Naegleria, Hartmanella, Vahlkampfia or Echinamoeba sp.).

  17. Partners in amphibian and reptile conservation 2013 annual report

    Science.gov (United States)

    Conrad, Paulette M.; Weir, Linda A.; Nanjappa, Priya

    2014-01-01

    Partners in Amphibian and Reptile Conservation (PARC) was established in 1999 to address the widespread declines, extinctions, and range reductions of amphibians and reptiles, with a focus on conservation of taxa and habitats in North America. Amphibians and reptiles are affected by a broad range of human activities, both as incidental effects of habitat alteration and direct effect from overexploitation; these animals are also challenged by the perception that amphibians and reptiles are either dangerous or of little environmental or economic value. However, PARC members understand these taxa are important parts of our natural an cultural heritage and they serve important roles in ecosystems throughout the world. With many amphibians and reptiles classified as threatened with extinction, conservation of these animals has never been more important.

  18. Amphibian recovery after a decrease in acidic precipitation.

    Science.gov (United States)

    Dolmen, Dag; Finstad, Anders Gravbrøt; Skei, Jon Kristian

    2018-04-01

    We here report the first sign of amphibian recovery after a strong decline due to acidic precipitation over many decades and peaking around 1980-90. In 2010, the pH level of ponds and small lakes in two heavily acidified areas in southwestern Scandinavia (Aust-Agder and Østfold in Norway) had risen significantly at an (arithmetic) average of 0.14 since 1988-89. Parallel with the general rise in pH, amphibians (Rana temporaria, R. arvalis, Bufo bufo, Lissotriton vulgaris, and Triturus cristatus) had become significantly more common: the frequency of amphibian localities rose from 33% to 49% (n = 115), and the average number of amphibian species per locality had risen from 0.51 to 0.88. In two other (reference) areas, one with better buffering capacity (Telemark, n = 21) and the other with much less input of acidic precipitation (Nord-Trøndelag, n = 106), there were no significant changes in pH or amphibians.

  19. Amphibian haematology: Metamorphosis-related changes in blood cells

    DEFF Research Database (Denmark)

    Rosenkilde, Per; Sørensen, Inger; Ussing, Anne Phaff

    1995-01-01

    Zoofysiologi, Amphibian metamorphosis, Haematology, Immunosuppression, Immunological Tolerance, Protozoan Infection, metamorfose, springpadder, ontogenese, halepadder.......Zoofysiologi, Amphibian metamorphosis, Haematology, Immunosuppression, Immunological Tolerance, Protozoan Infection, metamorfose, springpadder, ontogenese, halepadder....

  20. Diseases of amphibian eggs and embryos

    Science.gov (United States)

    Green, D.E.; Converse, K.A.; Majumdar, S.K.; Huffman, J.E.; Brenner, F.J.; Panah, A.I.

    2005-01-01

    Amphibians generally are prolific egg producers. In tropical and semi-tropical regions, deposition of eggs may occur year-round or may coincide with rainy seasons, while in temperate regions, deposition of eggs usually occurs immediately after emergence from hibernation. Numbers of eggs produced by each species may vary from a few dozen to thousands. Accordingly, some eggs may be infertile and wastage of embryos is to be expected. Fertility, viability and decomposition of eggs and embryos must be considered before it is assumed that diseases are present. An important consideration in the evaluation of egg masses is the fact that some will contain infertile and non-viable eggs. These infertile and nonviable eggs will undergo decomposition and they may appear similar to eggs that are infected by a pathogen. Evaluation of egg masses and embryos for the presence of disease may require repeated observations in a given breeding season as well as continued monitoring of egg masses during their growth and development and over successive breeding seasons. Amphibian eggs rarely are subjected to a comprehensive health (diagnostic) examination; hence, there is scant literature on the diseases of this life stage. Indeed, the eggs of some North American amphibians have yet to be described. Much basic physiology and normal biomedical baseline data on amphibian eggs is lacking. For example, it is known that the aquatic eggs of some species of shrimp quickly are coated by a protective and commensal bacterium that effectively impedes invasion of the eggs by other environmental organisms and potential pathogens. In the absence of this bacterium, shrimp eggs are rapidly killed by other bacteria and fungi (Green, 2001). The possibility that amphibian eggs also have important symbiotic or commensal bacteria needs to be investigated. Furthermore, the quantity and types of chemicals in the normal gelatinous capsules of amphibian eggs have scarcely been examined. Abnormalities of the

  1. DISTRIBUTION PATTERNS OF LENTIC-BREEDING AMPHIBIANS IN RELATION OF ULTRAVIOLET RADIATION EXPOSURE IN WESTERN NORTH AMERICA

    Science.gov (United States)

    An increase in ultraviolet (UV-B) radiation has been posited to be a potential factor in the decline of some amphibian population...Much more work is still needed to determine whether UV-B, either alone or in concert with other factors, is causing widespread population losses in ...

  2. Invasive reptiles and amphibians.

    Science.gov (United States)

    Moutou, F; Pastoret, P P

    2010-08-01

    Although they are frequently lumped together, reptiles and amphibians belong to two very different zoological groups. Nevertheless, one fact is clear: while numerous reptile and amphibian species on Earth are in decline, others have taken advantage of trade or human movements to become established in new lands, adopting different, and sometimes unusual, strategies. The authors have taken a few examples from these two zoological groups that illustrate the majority of cases. A brief analysis of the causes and effects of their introductions into new areas reveals connections with economic interests, trade in companion animals, medical research and public health.

  3. From tails to toes: developing nonlethal tissue indicators of mercury exposure in five amphibian species.

    Science.gov (United States)

    Pfleeger, Adam Z; Eagles-Smith, Collin A; Kowalski, Brandon M; Herring, Garth; Willacker, James J; Jackson, Allyson K; Pierce, John R

    2016-04-01

    Exposure to environmental contaminants has been implicated as a factor in global amphibian decline. Mercury (Hg) is a particularly widespread contaminant that biomagnifies in amphibians and can cause a suite of deleterious effects. However, monitoring contaminant exposure in amphibian tissues may conflict with conservation goals if lethal take is required. Thus, there is a need to develop non-lethal tissue sampling techniques to quantify contaminant exposure in amphibians. Some minimally invasive sampling techniques, such as toe-clipping, are common in population-genetic research, but it is unclear if these methods can adequately characterize contaminant exposure. We examined the relationships between mercury (Hg) concentrations in non-lethally sampled tissues and paired whole-bodies in five amphibian species. Specifically, we examined the utility of three different tail-clip sections from four salamander species and toe-clips from one anuran species. Both tail and toe-clips accurately predicted whole-body THg concentrations, but the relationships differed among species and the specific tail-clip section or toe that was used. Tail-clips comprised of the distal 0-2 cm segment performed the best across all salamander species, explaining between 82 and 92% of the variation in paired whole-body THg concentrations. Toe-clips were less effective predictors of frog THg concentrations, but THg concentrations in outer rear toes accounted for up to 79% of the variability in frog whole-body THg concentrations. These findings suggest non-lethal sampling of tails and toes has potential applications for monitoring contaminant exposure and risk in amphibians, but care must be taken to ensure consistent collection and interpretation of samples.

  4. Predation of Ladybird Beetles (Coleoptera: Coccinellidae) by Amphibians.

    Science.gov (United States)

    Sloggett, John J

    2012-07-18

    Studies of predation of ladybird beetles (Coccinellidae) have focused on a limited number of predator taxa, such as birds and ants, while other potential predators have received limited attention. I here consider amphibians as predators of ladybirds. Published amphibian gut analyses show that ladybirds are quite often eaten by frogs and toads (Anura), with recorded frequencies reaching up to 15% of dietary items. Salamanders (Caudata) eat ladybirds less frequently, probably as their habits less often bring them into contact with the beetles. Amphibians do not appear to be deleteriously affected by the potentially toxic alkaloids that ladybirds possess. Amphibians, especially frogs and toads, use primarily prey movement as a release cue to attack their food; it is thus likely that their ability to discriminate against ladybirds and other chemically defended prey is limited. Because of this poor discriminatory power, amphibians have apparently evolved non-specific resistance to prey defensive chemicals, including ladybird alkaloids. Although amphibian-related ladybird mortality is limited, in certain habitats it could outweigh mortality from more frequently studied predators, notably birds. The gut analyses from the herpetological literature used in this study, suggest that in studying predation of insects, entomologists should consider specialized literature on other animal groups.

  5. amphibian_biomarker_data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Amphibian metabolite data used in Snyder, M.N., Henderson, W.M., Glinski, D.G., Purucker, S. T., 2017. Biomarker analysis of american toad (Anaxyrus americanus) and...

  6. Low prevalence of chytrid fungus (Batrachochytrium dendrobatidis) in amphibians of U.S. headwater streams

    Science.gov (United States)

    Hossack, Blake R.; Adams, Michael J.; Campbell Grant, Evan H.; Pearl, Chistopher A.; Bettaso, James B.; Barichivich, William J.; Lowe, Winsor H.; True, Kimberly; Ware, Joy L.; Corn, Paul Stephen

    2010-01-01

    Many declines of amphibian populations have been associated with chytridiomycosis, a disease caused by the aquatic fungus Batrachochytrium dendrobatidis (Bd). Despite the relatively high prevalence of chytridiomycosis in stream amphibians globally, most surveys in North America have focused primarily on wetland-associated species, which are frequently infected. To better understand the distribution and prevalence of Bd in headwater amphibian communities, we sampled 452 tailed frogs (Ascaphus truei and Ascaphus montanus) and 304 stream salamanders (seven species in the Dicamptodontidae and Plethodontidae) for Bd in 38, first- to third-order streams in five montane areas across the United States. We tested for presence of Bd by using PCR on skin swabs from salamanders and metamorphosed tailed frogs or the oral disc of frog larvae. We detected Bd on only seven individuals (0.93%) in four streams. Based on our study and results from five other studies that have sampled headwater- or seep-associated amphibians in the United States, Bd has been detected on only 3% of 1,322 individuals from 21 species. These results differ strongly from surveys in Central America and Australia, where Bd is more prevalent on stream-breeding species, as well as results from wetland-associated anurans in the same regions of the United States that we sampled. Differences in the prevalence of Bd between stream- and wetland-associated amphibians in the United States may be related to species-specific variation in susceptibility to chytridiomycosis or habitat differences.

  7. Analysis of a Mathematical Model of Emerging Infectious Disease Leading to Amphibian Decline

    OpenAIRE

    Dur-e-Ahmad, Muhammad; Imran, Mudassar; Khan, Adnan

    2014-01-01

    We formulate a three-dimensional deterministic model of amphibian larvae population to investigate the cause of extinction due to the infectious disease. The larvae population of the model is subdivided into two classes, exposed and unexposed, depending on their vulnerability to disease. Reproduction ratio ${\\scr R}_{0}$ has been calculated and we have shown that if ${\\scr R}_{0}1$ , we discussed different scenarios under which an infected population can survive or be eliminated using stabili...

  8. Global patterns of amphibian phylogenetic diversity

    DEFF Research Database (Denmark)

    Fritz, Susanne; Rahbek, Carsten

    2012-01-01

    Aim  Phylogenetic diversity can provide insight into how evolutionary processes may have shaped contemporary patterns of species richness. Here, we aim to test for the influence of phylogenetic history on global patterns of amphibian species richness, and to identify areas where macroevolutionary...... processes such as diversification and dispersal have left strong signatures on contemporary species richness. Location  Global; equal-area grid cells of approximately 10,000 km2. Methods  We generated an amphibian global supertree (6111 species) and repeated analyses with the largest available molecular...... phylogeny (2792 species). We combined each tree with global species distributions to map four indices of phylogenetic diversity. To investigate congruence between global spatial patterns of amphibian species richness and phylogenetic diversity, we selected Faith’s phylogenetic diversity (PD) index...

  9. Cool temperatures reduce antifungal activity of symbiotic bacteria of threatened amphibians--implications for disease management and patterns of decline.

    Directory of Open Access Journals (Sweden)

    Joshua H Daskin

    Full Text Available Chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd, is a widespread disease of amphibians responsible for population declines and extinctions. Some bacteria from amphibians' skins produce antimicrobial substances active against Bd. Supplementing populations of these cutaneous antifungal bacteria might help manage chytridiomycosis in wild amphibians. However, the activity of protective bacteria may depend upon environmental conditions. Biocontrol of Bd in nature thus requires knowledge of how environmental conditions affect their anti-Bd activity. For example, Bd-driven amphibian declines have often occurred at temperatures below Bd's optimum range. It is possible these declines occurred due to reduced anti-Bd activity of bacterial symbionts at cool temperatures. Better understanding of the effects of temperature on chytridiomycosis development could also improve risk evaluation for amphibian populations yet to encounter Bd. We characterized, at a range of temperatures approximating natural seasonal variation, the anti-Bd activity of bacterial symbionts from the skins of three species of rainforest tree frogs (Litoria nannotis, Litoria rheocola, and Litoria serrata. All three species declined during chytridiomycosis outbreaks in the late 1980s and early 1990s and have subsequently recovered to differing extents. We collected anti-Bd bacterial symbionts from frogs and cultured the bacteria at constant temperatures from 8 °C to 33 °C. Using a spectrophotometric assay, we monitored Bd growth in cell-free supernatants (CFSs from each temperature treatment. CFSs from 11 of 24 bacteria showed reduced anti-Bd activity in vitro when they were produced at cool temperatures similar to those encountered by the host species during population declines. Reduced anti-Bd activity of metabolites produced at low temperatures may, therefore, partially explain the association between Bd-driven declines and cool temperatures. We show that to

  10. Cool temperatures reduce antifungal activity of symbiotic bacteria of threatened amphibians--implications for disease management and patterns of decline.

    Science.gov (United States)

    Daskin, Joshua H; Bell, Sara C; Schwarzkopf, Lin; Alford, Ross A

    2014-01-01

    Chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), is a widespread disease of amphibians responsible for population declines and extinctions. Some bacteria from amphibians' skins produce antimicrobial substances active against Bd. Supplementing populations of these cutaneous antifungal bacteria might help manage chytridiomycosis in wild amphibians. However, the activity of protective bacteria may depend upon environmental conditions. Biocontrol of Bd in nature thus requires knowledge of how environmental conditions affect their anti-Bd activity. For example, Bd-driven amphibian declines have often occurred at temperatures below Bd's optimum range. It is possible these declines occurred due to reduced anti-Bd activity of bacterial symbionts at cool temperatures. Better understanding of the effects of temperature on chytridiomycosis development could also improve risk evaluation for amphibian populations yet to encounter Bd. We characterized, at a range of temperatures approximating natural seasonal variation, the anti-Bd activity of bacterial symbionts from the skins of three species of rainforest tree frogs (Litoria nannotis, Litoria rheocola, and Litoria serrata). All three species declined during chytridiomycosis outbreaks in the late 1980s and early 1990s and have subsequently recovered to differing extents. We collected anti-Bd bacterial symbionts from frogs and cultured the bacteria at constant temperatures from 8 °C to 33 °C. Using a spectrophotometric assay, we monitored Bd growth in cell-free supernatants (CFSs) from each temperature treatment. CFSs from 11 of 24 bacteria showed reduced anti-Bd activity in vitro when they were produced at cool temperatures similar to those encountered by the host species during population declines. Reduced anti-Bd activity of metabolites produced at low temperatures may, therefore, partially explain the association between Bd-driven declines and cool temperatures. We show that to avoid

  11. Amphibian Declines Are Not Uniquely High amongst the Vertebrates: Trend Determination and the British Perspective

    Directory of Open Access Journals (Sweden)

    John Buckley

    2009-09-01

    Full Text Available Although amphibians have experienced major global declines and an increasing extinction rate, recent results indicate that they are not as uniquely disadvantaged as previously supposed. Acquisition of robust data is evidently crucial to the determination of both absolute and relative rates of biodiversity declines, and thus in prioritising conservation actions. In Britain there is arguably a longer history of recording, and attempting to conserve, a wide range of species groups than anywhere else in the world. This stems from the early activities of Victorian naturalists in the nineteenth century, the establishment of natural history societies and, since the mid-twentieth century, a range of national recording schemes and organisations actively involved in conservation. In this review we summarise comparative evidence for British amphibians and reptiles concerning historical abundance, population trends and their causes, and outline how they relate to the situation elsewhere in Europe (and possibly the World. We discuss possible reasons why the plight of ectothermic vertebrates (fish, amphibians and reptiles seems generally worse than that of endotherms (birds and mammals, as well as research priorities and factors likely to impact amphibians and reptile conservation in future.

  12. Status and trends of amphibian declines and extinctions worldwide.

    Science.gov (United States)

    Stuart, Simon N; Chanson, Janice S; Cox, Neil A; Young, Bruce E; Rodrigues, Ana S L; Fischman, Debra L; Waller, Robert W

    2004-12-03

    The first global assessment of amphibians provides new context for the well-publicized phenomenon of amphibian declines. Amphibians are more threatened and are declining more rapidly than either birds or mammals. Although many declines are due to habitat loss and overutilization, other, unidentified processes threaten 48% of rapidly declining species and are driving species most quickly to extinction. Declines are nonrandom in terms of species' ecological preferences, geographic ranges, and taxonomic associations and are most prevalent among Neotropical montane, stream-associated species. The lack of conservation remedies for these poorly understood declines means that hundreds of amphibian species now face extinction.

  13. Dry creek long-term watershed study: buffer zone performance as viable amphibian habitat

    Science.gov (United States)

    Brooke L. Talley; Thomas L. Crisman

    2006-01-01

    As bioindicators, amphibians typically require both terrestrial and aquatic habitats to complete their life cycles. Pre- timber-harvest monitoring (December 2002 through September 2003) of salamander and frog (Hylidae) populations was conducted in four watersheds of Decatur County, GA. Post- timber-harvest monitoring (December 2003 through September...

  14. Practitioner and scientist perceptions of successful amphibian conservation.

    Science.gov (United States)

    Meredith, Helen M R; St John, Freya A V; Collen, Ben; Black, Simon A; Griffiths, Richard A

    2018-04-01

    Conservation requires successful outcomes. However, success is perceived in many different ways depending on the desired outcome. Through a questionnaire survey, we examined perceptions of success among 355 scientists and practitioners working on amphibian conservation from over 150 organizations in more than 50 countries. We also sought to identify how different types of conservation actions and respondent experience and background influenced perceptions. Respondents identified 4 types of success: species and habitat improvements (84% of respondents); effective program management (36%); outreach initiatives such as education and public engagement (25%); and the application of science-based conservation (15%). The most significant factor influencing overall perceived success was reducing threats. Capacity building was rated least important. Perceptions were influenced by experience, professional affiliation, involvement in conservation practice, and country of residence. More experienced practitioners associated success with improvements to species and habitats and less so with education and engagement initiatives. Although science-based conservation was rated as important, this factor declined in importance as the number of programs a respondent participated in increased, particularly among those from less economically developed countries. The ultimate measure of conservation success-population recovery-may be difficult to measure in many amphibians; difficult to relate to the conservation actions intended to drive it; and difficult to achieve within conventional funding time frames. The relaunched Amphibian Conservation Action Plan provides a framework for capturing lower level processes and outcomes, identifying gaps, and measuring progress. © 2017 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

  15. Red List of amphibians and reptiles of the Wadden Sea area

    Science.gov (United States)

    Fog, K.; Podloucky, R.; Dierking, U.; Stumpel, A. H. P.

    1996-10-01

    In the Wadden Sea, in total, 8 species of amphibians and 4 species of reptiles are threatened in at least one subregion. Of these, 7 species of amphibians and all 4 species of reptiles are threatened in the entire area and are therefore placed on the trilateral Red List. 1 species of the listed reptiles is (probably) extinct in the entire Wadden Sea area. The status of 1 species of amphibians is endangered, the status of (probably) 4 species of amphibians and 3 species of reptiles are vulnerable and of 2 species of amphibians susceptible.

  16. Invasive and introduced reptiles and amphibians: Chapter 28

    Science.gov (United States)

    Reed, Robert N.; Krysko, Kenneth L.; Mader, Douglas R.; Divers, Stephen J.

    2014-01-01

    Why is there a section on introduced amphibians and reptiles in this volume, and why should veterinarians care about this issue? Globally, invasive species are a major threat to the stability of native ecosystems,1,2 and amphibians and reptiles are attracting increased attention as potential invaders. Some introduced amphibians and reptiles have had a major impact (e.g., Brown Tree Snakes [Boiga irregularis] wiping out the native birds of Guam3 or Cane Toads [Rhinella marina] poisoning native Australian predators).4 For the vast majority of species, however, the ecological, economic, and sociopolitical effects of introduced amphibians and reptiles are generally poorly quantified, largely because of a lack of focused research effort rather than because such effects are nonexistent. This trend is alarming given that rates of introduction have increased exponentially in recent decades.

  17. Diversity of Andean amphibians of the Tamá National Natural Park in Colombia: a survey for the presence of Batrachochytrium dendrobatidis

    Energy Technology Data Exchange (ETDEWEB)

    Acevedo, A.A.; Franco, R.; Carrero, D.A.

    2016-07-01

    Changes in diversity and possible decreases in populations of amphibians have not yet been determined in many areas in the Andes. This study aimed to develop an inventory of the biodiversity of amphibians in the Andean areas of the Tamá National Natural Park (Tamá NNP) and to evaluate the patterns of infection by Batrachochytrium dendrobatidis (Bd) in preserved and degraded areas. We performed samplings focused on three habitats (forest, open areas and streams) in four localities from 2,000 to 3,200 m in altitude. Fourteen species were recorded, 12 of which were positive for Bd. A total of 541 individuals were diagnosed and 100 were positive. Our analyses showed that preserved areas play an important role in keeping many individuals Bd–free as compared to those in degraded areas. This was the first study to evaluate diversity and infection by Bd in the northeast region of Colombia. Our findings may help improve our knowledge of the diversity of amphibian species in the area and facilitate the implementation of action plans to mitigate the causes associated with the decrease in amphibian populations. (Author)

  18. Swabbing often fails to detect amphibian Chytridiomycosis under conditions of low infection load.

    Directory of Open Access Journals (Sweden)

    Jaehyub Shin

    Full Text Available The pathogenic chytrid fungus, Batrachochytrium dendrobatidis (denoted Bd, causes large-scale epizootics in naïve amphibian populations. Intervention strategies to rapidly respond to Bd incursions require sensitive and accurate diagnostic methods. Chytridiomycosis usually is assessed by quantitative polymerase chain reaction (qPCR amplification of amphibian skin swabs. Results based on this method, however, sometimes yield inconsistent results on infection status and inaccurate scores of infection intensity. In Asia and other regions where amphibians typically bear low Bd loads, swab results are least reliable. We developed a Bd-sampling method that collects zoospores released by infected subjects into an aquatic medium. Bd DNA is extracted by filters and amplified by nested PCR. Using laboratory colonies and field populations of Bombina orientalis, we compare results with those obtained on the same subjects by qPCR of DNA extracted from swabs. Many subjects, despite being diagnosed as Bd-negative by conventional methods, released Bd zoospores into collection containers and thus must be considered infected. Infection loads determined from filtered water were at least 1000 times higher than those estimated from swabs. Subjects significantly varied in infection load, as they intermittently released zoospores, over a 5-day period. Thus, the method might be used to compare the infectivity of individuals and study the periodicity of zoospore release. Sampling methods based on water filtration can dramatically increase the capacity to accurately diagnose chytridiomycosis and contribute to a better understanding of the interactions between Bd and its hosts.

  19. Species-level correlates of susceptibility to the pathogenic amphibian fungus Batrachochytrium dendrobatidis in the United States

    Science.gov (United States)

    Betsy A. Bancroft; Barbara A. Han; Catherine L. Searle; Lindsay M. Biga; Deanna H. Olson; Lee B. Kats; Joshua J. Lawler; Andrew R. Blaustein

    2011-01-01

    Disease is often implicated as a factor in population declines of wildlife and plants. Understanding the characteristics that may predispose a species to infection by a particular pathogen can help direct conservation efforts. Recent declines in amphibian populations world-wide are a major conservation issue and may be caused in part by a fungal pathogen, ...

  20. Are snake populations in widespread decline?

    OpenAIRE

    Reading, C. J.; Luiselli, L. M.; Akani, G. C.; Bonnet, X.; Amori, G.; Ballouard, J. M.; Filippi, E.; Naulleau, G.; Pearson, D.; Rugiero, L.

    2010-01-01

    Long-term studies have revealed population declines in fishes, amphibians, reptiles, birds and mammals. In birds, and particularly amphibians, these declines are a global phenomenon whose causes are often unclear. Among reptiles, snakes are top predators and therefore a decline in their numbers may have serious consequences for the functioning of many ecosystems. Our results show that, of 17 snake populations (eight species) from the UK, France, Italy, Nigeria and Australia, 11 have declined ...

  1. Population pharmacokinetics of olprinone in healthy male volunteers

    Directory of Open Access Journals (Sweden)

    Kunisawa T

    2014-03-01

    Full Text Available Takayuki Kunisawa,1 Hidefumi Kasai,2 Makoto Suda,2 Manabu Yoshimura,3 Ami Sugawara,3 Yuki Izumi,3 Takafumi Iida,3 Atsushi Kurosawa,3 Hiroshi Iwasaki3 1Surgical Operation Department, Asahikawa Medical University Hospital, Hokkaido, Japan; 2Clinical Study Management Division, Bell Medical Solutions Inc, Tokyo, Japan; 3Department of Anesthesiology and Critical Care Medicine, Asahikawa Medical University, Hokkaido, Japan Background: Olprinone decreases the cardiac preload and/or afterload because of its vasodilatory effect and increases myocardial contractility by inhibiting phosphodiesterase III. Purpose: The objective of this study was to characterize the population pharmacokinetics of olprinone after a single continuous infusion in healthy male volunteers. Methods: We used 500 plasma concentration data points collected from nine healthy male volunteers for the study. The population pharmacokinetic analysis was performed using the nonlinear mixed effect model (NONMEM® software. Results: The time course of plasma concentration of olprinone was best described using a two-compartment model. The final pharmacokinetic parameters were total clearance (7.37 mL/minute/kg, distribution volume of the central compartment (134 mL/kg, intercompartmental clearance (7.75 mL/minute/kg, and distribution volume of the peripheral compartment (275 mL/kg. The interindividual variability in the total clearance was 12.4%, and the residual error variability (exponential and additive were 22.2% and 0.129 (standard deviation. The final pharmacokinetic model was assessed using a bootstrap method and visual predictive check. Conclusion: We developed a population pharmacokinetic model of olprinone in healthy male adults. The bootstrap method and visual predictive check showed that this model was appropriate. Our results might be used to develop the population pharmacokinetic model in patients. Keywords: phosphodiesterase III inhibitor, men, pharmacokinetic model

  2. Echocardiographic chamber quantification in a healthy Dutch population.

    Science.gov (United States)

    van Grootel, R W J; Menting, M E; McGhie, J; Roos-Hesselink, J W; van den Bosch, A E

    2017-12-01

    For accurate interpretation of echocardiographic measurements normative data are required, which are provided by guidelines. For this article, the hypothesis was that these cannot be extrapolated to the Dutch population, since in Dutch clinical practice often higher values are found, which may not be pathological but physiological. Therefore this study aimed to 1) obtain and propose normative values for cardiac chamber quantification in a healthy Dutch population and 2) determine influences of baseline characteristics on these measurements. Prospectively recruited healthy subjects, aged 20-72 years (at least 28 subjects per age decade, equally distributed for gender) underwent physical examination and 2D and 3D echocardiography. Both ventricles and atria were assessed and volumes were calculated. 147 subjects were included (age 44 ± 14 years, 50% female). Overall, feasibility was good for both linear and volumetric measurements. Linear and volumetric parameters were consistently higher than current guidelines recommend, while functional parameters were in line with the guidelines. This was more so in the older population. 3D volumes were higher than 2D volumes. Gender dependency was seen in all body surface area (BSA) corrected volumes and with increasing age, ejection fractions decreased. This study provides 2D and 3D echocardiographic reference ranges for both ventricles and atria derived from a healthy Dutch population. BSA indexed volumes are gender-dependent, age did not influence ventricular volumes and a rise in blood pressure was independently associated with increased right ventricular volumes. The higher volumes found may be indicative for the Dutch population being the tallest in the world.

  3. [The general methodological approaches identifying strategic positions in developing healthy lifestyle of population].

    Science.gov (United States)

    Dorofeev, S B; Babenko, A I

    2017-01-01

    The article deals with analysis of national and international publications concerning methodological aspects of elaborating systematic approach to healthy life-style of population. This scope of inquiry plays a key role in development of human capital. The costs related to healthy life-style are to be considered as personal investment into future income due to physical incrementation of human capital. The definitions of healthy life-style, its categories and supportive factors are to be considered in the process of development of strategies and programs of healthy lifestyle. The implementation of particular strategies entails application of comprehensive information and educational programs meant for various categories of population. Therefore, different motivation techniques are to be considered for children, adolescents, able-bodied population, the elderly. This approach is to be resulted in establishing particular responsibility for national government, territorial administrations, health care administrations, employers and population itself. The necessity of complex legislative measures is emphasized. The recent social hygienic studies were focused mostly on particular aspects of development of healthy life-style of population. Hence, the demand for long term exploration of development of organizational and functional models implementing medical preventive measures on the basis of comprehensive information analysis using statistical, sociological and professional expertise.

  4. Possibilties of using amphibians and reptiles to indicate environmental pollution

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, V.S.; Sharygin, S.A.

    1981-01-01

    Data on the presence of certain toxic elements in organisms of amphibians and reptiles are reported. Differences in chemical composition of organisms of amphibians and reptiles living in wild biotopes and in settlements are shown. Analysis of microelement concentration in organisms of amphibians and reptiles can be used to detect pollution in urban areas.

  5. Carotenoids and amphibians: effects on life history and susceptibility to the infectious pathogen, Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Cothran, Rickey D; Gervasi, Stephanie S; Murray, Cindy; French, Beverly J; Bradley, Paul W; Urbina, Jenny; Blaustein, Andrew R; Relyea, Rick A

    2015-01-01

    Carotenoids are considered beneficial nutrients because they provide increased immune capacity. Although carotenoid research has been conducted in many vertebrates, little research has been done in amphibians, a group that is experiencing global population declines from numerous causes, including disease. We raised two amphibian species through metamorphosis on three carotenoid diets to quantify the effects on life-history traits and post-metamorphic susceptibility to a fungal pathogen (Batrachochytrium dendrobatidis; Bd). Increased carotenoids had no effect on survival to metamorphosis in gray treefrogs (Hyla versicolor) but caused lower survival to metamorphosis in wood frogs [Lithobates sylvaticus (Rana sylvatica)]. Increased carotenoids caused both species to experience slower development and growth. When exposed to Bd after metamorphosis, wood frogs experienced high mortality, and the carotenoid diets had no mitigating effects. Gray treefrogs were less susceptible to Bd, which prevented an assessment of whether carotenoids could mitigate the effects of Bd. Moreover, carotenoids had no effect on pathogen load. As one of only a few studies examining the effects of carotenoids on amphibians and the first to examine potential interactions with Bd, our results suggest that carotenoids do not always serve amphibians in the many positive ways that have become the paradigm in other vertebrates.

  6. Sperm motility of externally fertilizing fish and amphibians.

    Science.gov (United States)

    Browne, R K; Kaurova, S A; Uteshev, V K; Shishova, N V; McGinnity, D; Figiel, C R; Mansour, N; Agney, D; Wu, M; Gakhova, E N; Dzyuba, B; Cosson, J

    2015-01-01

    We review the phylogeny, sperm competition, morphology, physiology, and fertilization environments of the sperm of externally fertilizing fish and amphibians. Increased sperm competition in both fish and anurans generally increases sperm numbers, sperm length, and energy reserves. The difference between the internal osmolarity and iconicity of sperm cells and those of the aquatic medium control the activation, longevity, and velocity of sperm motility. Hypo-osmolarity of the aquatic medium activates the motility of freshwater fish and amphibian sperm and hyperosmolarity activates the motility of marine fish sperm. The average longevity of the motility of marine fish sperm (~550 seconds) was significantly (P amphibian sperm in general and anurans reversion from internal to external fertilization. Our findings provide a greater understanding of the reproductive biology of externally fertilizing fish and amphibians, and a biological foundation for the further development of reproduction technologies for their sustainable management.

  7. Clear-cutting affects habitat connectivity for a forest amphibian by decreasing permeability to juvenile movements.

    Science.gov (United States)

    Popescu, Viorel D; Hunter, Malcolm L

    2011-06-01

    Conservation of forest amphibians is dependent on finding the right balance between management for timber production and meeting species' habitat requirements. For many pond-breeding amphibians, successful dispersal of the juvenile stage is essential for long-term population persistence. We investigated the influence of timber-harvesting practices on the movements of juvenile wood frogs (Lithobates sylvaticus). We used a chronosequence of stands produced by clear-cutting to evaluate how stand age affects habitat permeability to movements. We conducted experimental releases of juveniles in 2008 (n = 350) and 2009 (n = 528) in unidirectional runways in four treatments: mature forest, recent clearcut, 11-year-old, and 20-year-old regeneration. The runways were 50 x 2.5-m enclosures extending into each treatment, perpendicular to a distinct edge, with four tracking stations at 10, 20, 30, and 40 m from the edge. We recorded the number of animals reaching each tracking station, and the proportion of animals changing their direction of movement at each distance. We found that the mature forest was 3.1 and 3.7 times more permeable than the 11-year-old regeneration and the recent clearcut, respectively. Animals actively avoided open-canopy habitats and sharp edges; significantly more animals returned toward the closed-canopy forest at 0 m and 10 m in the less permeable treatments. There were no significant differences in habitat permeability between the mature forest and the 20-year-old regeneration. Our study is the first to directly assess habitat permeability to juvenile amphibian movement in relation to various forestry practices. We argue that habitat permeability at this scale is largely driven by the behavior of animals in relation to habitat disturbance and that caution needs to be used when using spatial modeling and expert-derived permeability values to assess connectivity of amphibian populations. The effects of clear-cutting on the migratory success of juvenile

  8. Despite Buffers, Experimental Forest Clearcuts Impact Amphibian Body Size and Biomass.

    Science.gov (United States)

    Veysey Powell, Jessica S; Babbitt, Kimberly J

    2015-01-01

    Forest buffers are a primary tool used to protect wetland-dependent wildlife. Though implemented widely, buffer efficacy is untested for most amphibian species. Consequently, it remains unclear whether buffers are sufficient for maintaining amphibian populations and if so, how wide buffers should be. We present evidence from a six-year, landscape-scale experiment testing the impacts of clearcutting, buffer width, and hydroperiod on body size and condition and biomass of breeding adults for two amphibian species at 11 vernal pools in the northeastern United States. We randomly assigned treatments (i.e., reference, 100m buffer, 30m buffer) across pools, clearcut to create buffers, and captured all spotted salamanders and wood frogs. Clearcuts strongly and negatively impacted size, condition, and biomass, but wider buffers mitigated effect magnitude and duration. Among recaptured individuals, for example, 30m-treatment salamanders were predicted to be about 9.5 mm shorter than, while 100m-treatment salamanders did not differ in length from, reference-treatment salamanders. Similarly, among recaptured frogs, mean length in the 30m treatment was predicted to decrease by about 1 mm/year, while in the 100m and reference treatments, length was time-invariant. Some, but not all, metrics recovered with time. For example, female new-captured and recaptured salamanders were predicted, respectively and on average, to weigh 4.5 and 7 g less in the 30m versus reference treatment right after the cut. While recaptured-female mass was predicted to recover by 9.5 years post-cut, new-captured-female mass did not recover. Hydroperiod was an important mediator: in the 100m treatment, cutting predominately affected pools that were stressed hydrologically. Overall, salamanders and female frogs were impacted more than male frogs. Our results highlight the importance of individualized metrics like body size, which can reveal sublethal effects and illuminate mechanisms by which habitat

  9. Despite Buffers, Experimental Forest Clearcuts Impact Amphibian Body Size and Biomass.

    Directory of Open Access Journals (Sweden)

    Jessica S Veysey Powell

    Full Text Available Forest buffers are a primary tool used to protect wetland-dependent wildlife. Though implemented widely, buffer efficacy is untested for most amphibian species. Consequently, it remains unclear whether buffers are sufficient for maintaining amphibian populations and if so, how wide buffers should be. We present evidence from a six-year, landscape-scale experiment testing the impacts of clearcutting, buffer width, and hydroperiod on body size and condition and biomass of breeding adults for two amphibian species at 11 vernal pools in the northeastern United States. We randomly assigned treatments (i.e., reference, 100m buffer, 30m buffer across pools, clearcut to create buffers, and captured all spotted salamanders and wood frogs. Clearcuts strongly and negatively impacted size, condition, and biomass, but wider buffers mitigated effect magnitude and duration. Among recaptured individuals, for example, 30m-treatment salamanders were predicted to be about 9.5 mm shorter than, while 100m-treatment salamanders did not differ in length from, reference-treatment salamanders. Similarly, among recaptured frogs, mean length in the 30m treatment was predicted to decrease by about 1 mm/year, while in the 100m and reference treatments, length was time-invariant. Some, but not all, metrics recovered with time. For example, female new-captured and recaptured salamanders were predicted, respectively and on average, to weigh 4.5 and 7 g less in the 30m versus reference treatment right after the cut. While recaptured-female mass was predicted to recover by 9.5 years post-cut, new-captured-female mass did not recover. Hydroperiod was an important mediator: in the 100m treatment, cutting predominately affected pools that were stressed hydrologically. Overall, salamanders and female frogs were impacted more than male frogs. Our results highlight the importance of individualized metrics like body size, which can reveal sublethal effects and illuminate mechanisms by

  10. Amphibian commerce as a likely source of pathogen pollution.

    Science.gov (United States)

    Picco, Angela M; Collins, James P

    2008-12-01

    The commercial trade of wildlife occurs on a global scale. In addition to removing animals from their native populations, this trade may lead to the release and subsequent introduction of nonindigenous species and the pathogens they carry. Emerging infectious diseases, such as chytridiomycosis caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd), and ranaviral disease have spread with global trade in amphibians and are linked to amphibian declines and die-offs worldwide, which suggests that the commercial trade in amphibians may be a source of pathogen pollution. We screened tiger salamanders involved in the bait trade in the western United States for both ranaviruses and Bd with polymerase chain reaction and used oral reports from bait shops and ranavirus DNA sequences from infected bait salamanders to determine how these animals and their pathogens are moved geographically by commerce. In addition, we conducted 2 surveys of anglers to determine how often tiger salamanders are used as bait and how often they are released into fishing waters by anglers, and organized bait-shop surveys to determine whether tiger salamanders are released back into the wild after being housed in bait shops. Ranaviruses were detected in the tiger salamander bait trade in Arizona, Colorado, and New Mexico, and Bd was detected in Arizona bait shops. Ranaviruses were spread geographically through the bait trade. All tiger salamanders in the bait trade were collected from the wild, and in general they moved east to west and north to south, bringing with them their multiple ranavirus strains. Finally, 26-73% of anglers used tiger salamanders as fishing bait, 26-67% of anglers released tiger salamanders bought as bait into fishing waters, and 4% of bait shops released tiger salamanders back into the wild after they were housed in shops with infected animals. The tiger salamander bait trade in the western United States is a useful model for understanding the consequences of the

  11. Gridded Species Distribution, Version 1: Global Amphibians Presence Grids

    Data.gov (United States)

    National Aeronautics and Space Administration — The Global Amphibians Presence Grids of the Gridded Species Distribution, Version 1 is a reclassified version of the original grids of amphibian species distribution...

  12. Low levels of chemical anthropogenic pollution may threaten amphibians by impairing predator recognition.

    Science.gov (United States)

    Polo-Cavia, Nuria; Burraco, Pablo; Gomez-Mestre, Ivan

    2016-03-01

    Recent studies suggest that direct mortality and physiological effects caused by pollutants are major contributing factors to global amphibian decline. However, even sublethal concentrations of pollutants could be harmful if they combined with other factors to cause high mortality in amphibians. Here we show that sublethal concentrations of pollutants can disrupt the ability of amphibian larvae to recognize predators, hence increasing their risk of predation. This effect is indeed much more important since very low amounts of pollutants are ubiquitous, and environmental efforts are mostly directed towards preventing lethal spills. We analyzed the effects of two common contaminants (humic acid and ammonium nitrate) on the ability of tadpoles of the western spadefoot toad (Pelobates cultripes) to recognize chemical cues from a common predator, nymphs of the dragonfly Anax imperator. We compared the swimming activity of tadpoles in the presence and absence of water-borne chemical cues from dragonflies at different concentrations of humic acid and ammonium nitrate. Tadpoles reduced swimming activity in response to predator cues in the absence of pollutants, whereas they remained unresponsive to these cues when either humic acid or ammonium nitrate was added to the water, even at low concentrations. Moreover, changes in tadpole activity associated with the pollutants themselves were non-significant, indicating no toxic effect. Alteration of the natural chemical environment of aquatic systems by pollutants may be an important contributing cause for declines in amphibian populations, even at sublethal concentrations. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Saprolegniaceae identified on amphibian eggs throughout the Pacific Northwest, USA, by internal transcribed spacer sequences and phylogenetic analysis.

    Science.gov (United States)

    Petrisko, Jill E; Pearl, Christopher A; Pilliod, David S; Sheridan, Peter P; Williams, Charles F; Peterson, Charles R; Bury, R Bruce

    2008-01-01

    We assessed the diversity and phylogeny of Saprolegniaceae on amphibian eggs from the Pacific Northwest, with particular focus on Saprolegnia ferax, a species implicated in high egg mortality. We identified isolates from eggs of six amphibians with the internal transcribed spacer (ITS) and 5.8S gene regions and BLAST of the GenBank database. We identified 68 sequences as Saprolegniaceae and 43 sequences as true fungi from at least nine genera. Our phylogenetic analysis of the Saprolegniaceae included isolates within the genera Saprolegnia, Achlya and Leptolegnia. Our phylogeny grouped S. semihypogyna with Achlya rather than with the Saprolegnia reference sequences. We found only one isolate that grouped closely with S. ferax, and this came from a hatchery-raised salmon (Idaho) that we sampled opportunistically. We had representatives of 7-12 species and three genera of Saprolegniaceae on our amphibian eggs. Further work on the ecological roles of different species of Saprolegniaceae is needed to clarify their potential importance in amphibian egg mortality and potential links to population declines.

  14. Analysis of a Mathematical Model of Emerging Infectious Disease Leading to Amphibian Decline

    Directory of Open Access Journals (Sweden)

    Muhammad Dur-e-Ahmad

    2014-01-01

    Full Text Available We formulate a three-dimensional deterministic model of amphibian larvae population to investigate the cause of extinction due to the infectious disease. The larvae population of the model is subdivided into two classes, exposed and unexposed, depending on their vulnerability to disease. Reproduction ratio ℛ0 has been calculated and we have shown that if ℛ01, we discussed different scenarios under which an infected population can survive or be eliminated using stability and persistence analysis. Finally, we also used Hopf bifurcation analysis to study the stability of periodic solutions.

  15. Short-term exposure to warm microhabitats could explain amphibian persistence with Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Daskin, Joshua H; Alford, Ross A; Puschendorf, Robert

    2011-01-01

    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.

  16. Short-term exposure to warm microhabitats could explain amphibian persistence with Batrachochytrium dendrobatidis.

    Directory of Open Access Journals (Sweden)

    Joshua H Daskin

    Full Text Available 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.

  17. Climate change and amphibian diversity patterns in Mexico

    DEFF Research Database (Denmark)

    Ochoa-Ochoa, Leticia M.; Rodríguez, Pilar; Mora, Franz

    2012-01-01

    The aim of this article is to characterize at fine scale alpha and beta diversity patterns for Mexican amphibians and analyze how these patterns might change under a moderate climate-change scenario, highlighting the overall consequences for amphibian diversity at the country level. We used a geo...

  18. AMPHIBIAN COMMUNITIES IN BIOGEOCOENOSIS WITH DIFFERENT STAGES OF ANTHROPOGENIC CLYMAX

    Directory of Open Access Journals (Sweden)

    Marchenkovskaya А. А.

    2013-04-01

    Full Text Available We examined the abundance of juvenile (fingerlings and yearlings and sexually mature (3-6 years of various anurans at various biotopes with different degrees of anthropogenic influence. Population analysis has revealed that the number of juveniles in all the habitats are depended on type and level of anthropogenic influence. In all the habitats the most numerous species was synanthropic bufo viridis. In biotopes with high contamination of pollutants, only one species of amphibians - the marsh frog has populations with juveniles migrating here in the early fall. The highest number of mature individuals registered for the population of Bombina bombina, pelobates fuscus and in one biotope for hyla arborea. The populations of pelophylax ridibundus could be considered as the most balanced by number of juvenile and mature individuals.

  19. [Strategies for Conservation of Endangered Amphibian and Reptile Species].

    Science.gov (United States)

    Anan'eva, N B; Uteshev, V K; Orlova, N L; Gakhova, E N

    2015-01-01

    Strategies for conservation of endangered amphibian and reptile species are discussed. One-fifth of all vertebrates belongs to the category of "endangered species," and amphibians are first on the list (41%). Every fifth reptile species is in danger of extinction, and insufficient information is characteristic of every other fifth. As has been demonstrated, efficient development of a network of nature conservation areas, cryopreservation, and methods for laboratory breeding and reintroduction play.the key roles in adequate strategies for preservation of amphibians and reptiles.

  20. Reptiles and amphibians

    Science.gov (United States)

    Lovich, Jeffrey E.; Ennen, Joshua R.; Perrow, Martin

    2017-01-01

    Summary – We reviewed all the peer-reviewed scientific publications we could find on the known and potential effects of wind farm development, operation, maintenance, and decommissioning on reptiles and amphibians (collectively herpetofauna) worldwide. Both groups are declining globally due to a multitude of threats including energy development. Effect studies were limited to the long-term research by the authors on Agassiz’s Desert Tortoise ecology and behavior at single operational wind farm in California, US and an analysis of the effects of wind farm installation on species richness of vertebrates including reptiles and amphibians in northwestern Portugal. Research on Agassiz’s Desert Tortoise found few demonstrable differences in biological parameters between populations in the wind farm and those in more natural habitats. High reproductive output is due to the regional climate and not to the presence or operation of the wind farm. Site operations have resulted in death and injury to a small number of adult tortoises and over the long-term tortoises now appear to avoid the areas of greatest turbine concentration. Research in Portugal using models and simulations based on empirical data show that vertebrate species richness (including herpetofauna) decreased by almost 20% after the installation of only two large monopole turbines per 250 x 250 m plot. Knowledge of the known responses of herpetofauna to various disturbances allows identification of potential impacts from construction material acquisition in offsite areas, mortality and stress due to impacts of roads and related infrastructure, destruction and modification of habitat, habitat fragmentation and barriers to gene flow, noise, vibration, electromagnetic field generation, heat from buried high voltage transmission lines, alteration of local and regional climate, predator attraction, and increased risk of fire. Research on herpetofauna lags far behind what is needed and, in particular, before

  1. Genetic evidence for a high diversity and wide distribution of endemic strains of the pathogenic chytrid fungus Batrachochytrium dendrobatidis in wild Asian amphibians.

    Science.gov (United States)

    Bataille, Arnaud; Fong, Jonathan J; Cha, Moonsuk; Wogan, Guinevere O U; Baek, Hae Jun; Lee, Hang; Min, Mi-Sook; Waldman, Bruce

    2013-08-01

    Population declines and extinctions of amphibians have been attributed to the chytrid fungus Batrachochytrium dendrobatidis (Bd), especially one globally emerging recombinant lineage ('Bd-GPL'). We used PCR assays that target the ribosomal internal transcribed spacer region (ITS) of Bd to determine the prevalence and genetic diversity of Bd in South Korea, where Bd is widely distributed but is not known to cause morbidity or mortality in wild populations. We isolated Korean Bd strains from native amphibians with low infection loads and compared them to known worldwide Bd strains using 19 polymorphic SNP and microsatellite loci. Bd prevalence ranged between 12.5 and 48.0%, in 11 of 17 native Korean species, and 24.7% in the introduced bullfrog Lithobates catesbeianus. Based on ITS sequence variation, 47 of the 50 identified Korean haplotypes formed a group closely associated with a native Brazilian Bd lineage, separated from the Bd-GPL lineage. However, multilocus genotyping of three Korean Bd isolates revealed strong divergence from both Bd-GPL and the native Brazilian Bd lineages. Thus, the ITS region resolves genotypes that diverge from Bd-GPL but otherwise generates ambiguous phylogenies. Our results point to the presence of highly diversified endemic strains of Bd across Asian amphibian species. The rarity of Bd-GPL-associated haplotypes suggests that either this lineage was introduced into Korea only recently or Bd-GPL has been outcompeted by native Bd strains. Our results highlight the need to consider possible complex interactions among native Bd lineages, Bd-GPL and their associated amphibian hosts when assessing the spread and impact of Bd-GPL on worldwide amphibian populations. © 2013 John Wiley & Sons Ltd.

  2. Changes in behavioural responses to infrastructure affect local and regional connectivity – a simulation study on pond breeding amphibians

    DEFF Research Database (Denmark)

    Pontoppidan, Maj-Britt; Nachman, Gøsta Støger

    2013-01-01

    An extensive and expanding infrastructural network destroys and fragments natural habitat and has detrimental effect on abundance and population viability of many amphibian species. Roads function as barriers in the landscape. They separate local populations from each other or prevent access...... to necessary resources. Therefore, road density and traffic intensity in a region may have severe impact on regional as well as local connectivity. Amphibians may be able to detect and avoid unsuitable habitat. Individuals’ ability to avoid roads can reduce road mortality but at the same time road...... avoidance behaviour, can increase the barrier effect of the road and reduce connectivity. We use an individual based model to explore how changes in road mortality and road avoidance behaviour affect local and regional connectivity in a population of Moor frogs (Rana arvalis). The results indicate that road...

  3. Communal egg-laying in reptiles and amphibians: evolutionary patterns and hypotheses.

    Science.gov (United States)

    Doody, J Sean; Freedberg, Steve; Keogh, J Scott

    2009-09-01

    Communal egg-laying is widespread among animals, occurring in insects, mollusks, fish, amphibians, reptiles, and birds, just to name a few. While some benefits of communal egg-laying may be pervasive (e.g., it saves time and energy and may ensure the survival of mothers and their offspring), the remarkable diversity in the life histories of the animals that exhibit this behavior presents a great challenge to discovering any general explanation. Reptiles and amphibians offer ideal systems for investigating communal egg-laying because they generally lack parental care--a simplification that brings nest site choice behavior into sharp focus. We exhaustively reviewed the published literature for data on communal egg-laying in reptiles and amphibians. Our analysis demonstrates that the behavior is much more common than previously recognized (occurring in 481 spp.), especially among lizards (N = 255 spp.), where the behavior has evolved multiple times. Our conceptual review strongly suggests that different forces may be driving the evolution and maintenance of communal egg-laying in different taxa. Using a game theory approach, we demonstrate how a stable equilibrium may occur between solitary and communal layers, thus allowing both strategies to co-exist in some populations, and we discuss factors that may influence these proportions. We conclude by outlining future research directions for determining the proximate and ultimate causes of communal egg-laying.

  4. Female sexual arousal in amphibians.

    Science.gov (United States)

    Wilczynski, Walter; Lynch, Kathleen S

    2011-05-01

    Rather than being a static, species specific trait, reproductive behavior in female amphibians is variable within an individual during the breeding season when females are capable of reproductive activity. Changes in receptivity coincide with changes in circulating estrogen. Estrogen is highest at the point when females are ready to choose a male and lay eggs. At this time female receptivity (her probability of responding to a male vocal signal) is highest and her selectivity among conspecific calls (measured by her probability of responding to a degraded or otherwise usually unattractive male signal) is lowest. These changes occur even though females retain the ability to discriminate different acoustic characteristics of various conspecific calls. After releasing her eggs, female amphibians quickly become less receptive and more choosy in terms of their responses to male sexual advertisement signals. Male vocal signals stimulate both behavior and estrogen changes in amphibian females making mating more probable. The changes in female reproductive behavior are the same as those generally accepted as indicative of a change in female sexual arousal leading to copulation. They are situationally triggered, gated by interactions with males, and decline with the consummation of sexual reproduction with a chosen male. The changes can be triggered by either internal physiological state or by the presence of stimuli presented by males, and the same stimuli change both behavior and physiological (endocrine) state in such a way as to make acceptance of a male more likely. Thus amphibian females demonstrate many of the same general characteristics of changing female sexual state that in mammals indicate sexual arousal. Copyright © 2010 Elsevier Inc. All rights reserved.

  5. Signals of forest degradation in the demography of common Asian amphibians

    Directory of Open Access Journals (Sweden)

    Nancy E. Karraker

    2018-01-01

    Full Text Available Background Lowland areas in tropical East and Southeast Asia have a long history of conversion from forestland to agricultural land, with many remaining forests being chronically degraded by wood cutting, livestock grazing, and burning. Wetland-breeding amphibians that have evolved in lowland forests in the region have adjusted to changes in habitat composition caused by humans’ activities, and populations continue to persist. However, we have little understanding of the impacts of forest disturbance on these species beyond assessments of abundance and distribution, and species considered to be common and widespread have been largely neglected. Methods We examined body condition and sex ratios of toads (Duttaphrynus melanostictus, predation risk in treefrogs (2 Polypedates spp., and growth and survival of leaf litter frogs (2 Microhyla spp. in agricultural land, degraded forest, and intact forest in two study areas, Thailand and Hong Kong. Results Toad populations exhibited higher body condition and female-biased sex ratios in intact forest. Predation of treefrog embryos by flies was lower in intact and degraded forests than in agricultural land. Embryonic survival and larval growth and survival in leaf litter frogs were lower in intact forests than in agricultural land. Results for each study were similar between study areas. Discussion For three of five of these common amphibian species, we documented signals of forest loss and disturbance in their populations. Although these species occur in disturbed habitats, loss of forest cover continues to degrade aspects of their population demography. We urge conservation biologists to consider that populations of species appearing to be common, widespread, and tolerant of human disturbance may be eroding over time.

  6. Predicting breeding habitat for amphibians: a spatiotemporal analysis across Yellowstone National Park.

    Science.gov (United States)

    Bartelt, Paul E; Gallant, Alisa L; Klaver, Robert W; Wright, Chris K; Patla, Debra A; Peterson, Charles R

    2011-10-01

    The ability to predict amphibian breeding across landscapes is important for informing land management decisions and helping biologists better understand and remediate factors contributing to declines in amphibian populations. We built geospatial models of likely breeding habitats for each of four amphibian species that breed in Yellowstone National Park (YNP). We used field data collected in 2000-2002 from 497 sites among 16 basins and predictor variables from geospatial models produced from remotely sensed data (e.g., digital elevation model, complex topographic index, landform data, wetland probability, and vegetative cover). Except for 31 sites in one basin that were surveyed in both 2000 and 2002, all sites were surveyed once. We used polytomous regression to build statistical models for each species of amphibian from (1) field survey site data only, (2) field data combined with data from geospatial models, and (3) data from geospatial models only. Based on measures of receiver operating characteristic (ROC) scores, models of the second type best explained likely breeding habitat because they contained the most information (ROC values ranged from 0.70 to 0.88). However, models of the third type could be applied to the entire YNP landscape and produced maps that could be verified with reserve field data. Accuracy rates for models built for single years were highly variable, ranging from 0.30 to 0.78. Accuracy rates for models built with data combined from multiple years were higher and less variable, ranging from 0.60 to 0.80. Combining results from the geospatial multiyear models yielded maps of "core" breeding areas (areas with high probability values for all three years) surrounded by areas that scored high for only one or two years, providing an estimate of variability among years. Such information can highlight landscape options for amphibian conservation. For example, our models identify alternative areas that could be protected for each species

  7. All about Amphibians. Animal Life for Children. [Videotape].

    Science.gov (United States)

    2000

    This videotape teaches children about their favorite amphibious creatures, as well as amphibians' nearest cousins--toads, newts, and salamanders. Young students discover how these amazing creatures can live both in and out of water, learn about the amphibious life cycle, and compare the differences between amphibians and reptiles. This videotape…

  8. Habitat predictors of genetic diversity for two sympatric wetland-breeding amphibian species.

    Science.gov (United States)

    McKee, Anna M; Maerz, John C; Smith, Lora L; Glenn, Travis C

    2017-08-01

    Population genetic diversity is widely accepted as important to the conservation and management of wildlife. However, habitat features may differentially affect evolutionary processes that facilitate population genetic diversity among sympatric species. We measured genetic diversity for two pond-breeding amphibian species (Dwarf salamanders, Eurycea quadridigitata ; and Southern Leopard frogs, Lithobates sphenocephalus ) to understand how habitat characteristics and spatial scale affect genetic diversity across a landscape. Samples were collected from wetlands on a longleaf pine reserve in Georgia. We genotyped microsatellite loci for both species to assess population structures and determine which habitat features were most closely associated with observed heterozygosity and rarefied allelic richness. Both species exhibited significant population genetic structure; however, structure in Southern Leopard frogs was driven primarily by one outlier site. Dwarf salamander allelic richness was greater at sites with less surrounding road area within 0.5 km and more wetland area within 1.0 and 2.5 km, and heterozygosity was greater at sites with more wetland area within 0.5 km. In contrast, neither measure of Southern Leopard frog genetic diversity was associated with any habitat features at any scale we evaluated. Genetic diversity in the Dwarf salamander was strongly associated with land cover variables up to 2.5 km away from breeding wetlands, and/or results suggest that minimizing roads in wetland buffers may be beneficial to the maintenance of population genetic diversity. This study suggests that patterns of genetic differentiation and genetic diversity have associations with different habitat features across different spatial scales for two syntopic pond-breeding amphibian species.

  9. A Place to Call Home: Amphibian Use of Created and Restored Wetlands

    OpenAIRE

    Brown, Donald J.; Street, Garrett M.; Nairn, Robert W.; Forstner, Michael R. J.

    2012-01-01

    Loss and degradation of wetland habitats are major contributing factors to the global decline of amphibians. Creation and restoration of wetlands could be a valuable tool for increasing local amphibian species richness and abundance. We synthesized the peer-reviewed literature addressing amphibian use of created and restored wetlands, focusing on aquatic habitat, upland habitat, and wetland connectivity and configuration. Amphibian species richness or abundance at created and restored wetland...

  10. Culture Media and Individual Hosts Affect the Recovery of Culturable Bacterial Diversity from Amphibian Skin.

    Science.gov (United States)

    Medina, Daniel; Walke, Jenifer B; Gajewski, Zachary; Becker, Matthew H; Swartwout, Meredith C; Belden, Lisa K

    2017-01-01

    One current challenge in microbial ecology is elucidating the functional roles of the large diversity of free-living and host-associated bacteria identified by culture-independent molecular methods. Importantly, the characterization of this immense bacterial diversity will likely require merging data from culture-independent approaches with work on bacterial isolates in culture. Amphibian skin bacterial communities have become a recent focus of work in host-associated microbial systems due to the potential role of these skin bacteria in host defense against the pathogenic fungus Batrachochytrium dendrobatidis (Bd), which is associated with global amphibian population declines and extinctions. As there is evidence that some skin bacteria may inhibit growth of Bd and prevent infection in some cases, there is interest in using these bacteria as probiotic therapy for conservation of at-risk amphibians. In this study, we used skin swabs from American toads ( Anaxyrus americanus ) to: (1) assess the diversity and community structure of culturable amphibian skin bacteria grown on high and low nutrient culture media, (2) determine which culture media recover the highest proportion of the total skin bacterial community of individual toads relative to culture-independent data, and (3) assess whether the plated communities from the distinct media types vary in their ability to inhibit Bd growth in in-vitro assays. Overall, we found that culture media with low nutrient concentrations facilitated the growth of more diverse bacterial taxa and grew distinct communities relative to media with higher nutrient concentrations. Use of low nutrient media also resulted in culturing proportionally more of the bacterial diversity on individual toads relative to the overall community defined using culture-independent methods. However, while there were differences in diversity among media types, the variation among individual hosts was greater than variation among media types, suggesting

  11. Quantitative Proteomics of an Amphibian Pathogen, Batrachochytrium dendrobatidis, following Exposure to Thyroid Hormone.

    Science.gov (United States)

    Thekkiniath, Jose; Zabet-Moghaddam, Masoud; Kottapalli, Kameswara Rao; Pasham, Mithun R; San Francisco, Susan; San Francisco, Michael

    2015-01-01

    Batrachochytrium dendrobatidis (Bd), a chytrid fungus, has increasingly been implicated as a major factor in the worldwide decline of amphibian populations. The fungus causes chytridiomycosis in susceptible species leading to massive die-offs of adult amphibians. Although Bd infects the keratinized mouthparts of tadpoles and negatively affects foraging behavior, these infections are non-lethal. An important morphogen controlling amphibian metamorphosis is thyroid hormone (T3). Tadpoles may be infected with Bd and the fungus may be exposed to T3 during metamorphosis. We hypothesize that exposure of Bd to T3 may induce the expression of factors associated with host colonization and pathogenicity. We utilized a proteomics approach to better understand the dynamics of the Bd-T3 interaction. Using liquid chromatography-mass spectrometry (LC-MS), we generated a data set of a large number of cytoplasmic and membrane proteins following exposure of Bd to T3. From these data, we identified a total of 263 proteins whose expression was significantly changed following T3 exposure. We provide evidence for expression of an array of proteins that may play key roles in both genomic and non-genomic actions of T3 in Bd. Additionally, our proteomics study shows an increase in several proteins including proteases and a class of uncommon crinkler and crinkler-like effector proteins suggesting their importance in Bd pathogenicity as well as those involved in metabolism and energy transfer, protein fate, transport and stress responses. This approach provides insights into the mechanistic basis of the Bd-amphibian interaction following T3 exposure.

  12. Quantitative Proteomics of an Amphibian Pathogen, Batrachochytrium dendrobatidis, following Exposure to Thyroid Hormone.

    Directory of Open Access Journals (Sweden)

    Jose Thekkiniath

    Full Text Available Batrachochytrium dendrobatidis (Bd, a chytrid fungus, has increasingly been implicated as a major factor in the worldwide decline of amphibian populations. The fungus causes chytridiomycosis in susceptible species leading to massive die-offs of adult amphibians. Although Bd infects the keratinized mouthparts of tadpoles and negatively affects foraging behavior, these infections are non-lethal. An important morphogen controlling amphibian metamorphosis is thyroid hormone (T3. Tadpoles may be infected with Bd and the fungus may be exposed to T3 during metamorphosis. We hypothesize that exposure of Bd to T3 may induce the expression of factors associated with host colonization and pathogenicity. We utilized a proteomics approach to better understand the dynamics of the Bd-T3 interaction. Using liquid chromatography-mass spectrometry (LC-MS, we generated a data set of a large number of cytoplasmic and membrane proteins following exposure of Bd to T3. From these data, we identified a total of 263 proteins whose expression was significantly changed following T3 exposure. We provide evidence for expression of an array of proteins that may play key roles in both genomic and non-genomic actions of T3 in Bd. Additionally, our proteomics study shows an increase in several proteins including proteases and a class of uncommon crinkler and crinkler-like effector proteins suggesting their importance in Bd pathogenicity as well as those involved in metabolism and energy transfer, protein fate, transport and stress responses. This approach provides insights into the mechanistic basis of the Bd-amphibian interaction following T3 exposure.

  13. Amphibians and Reptiles from Paramakatoi and Kato, Guyana

    Science.gov (United States)

    MacCulloch, Ross D.; Reynolds, Robert P.

    2012-01-01

    We report the herpetofauna of two neighboring upland locations in west-central Guyana. Twenty amphibian and 24 reptile species were collected. Only 40% of amphibians and 12.5% of reptiles were collected in both locations. This is one of the few collections made at upland (750–800 m) locations in the Guiana Shield.

  14. Toxicity of road salt to Nova Scotia amphibians

    International Nuclear Information System (INIS)

    Collins, Sara J.; Russell, Ronald W.

    2009-01-01

    The deposition of chemical pollutants into roadside wetlands from runoff is a current environmental concern. In northern latitudes, a major pollutant in runoff water is salt (NaCl), used as de-icing agents. In this study, 26 roadside ponds were surveyed for amphibian species richness and chloride concentration. Acute toxicity tests (LC 50 ) were performed on five locally common amphibian species using a range of environmentally significant NaCl concentrations. Field surveys indicated that spotted salamanders (Ambystoma maculatum) and wood frogs (Rana sylvatica) did not occupy high chloride ponds. American toads (Bufo americanus) showed no pond preference based on chloride concentration. Acute toxicity tests showed spotted salamanders and wood frogs were most sensitive to chloride, and American toads were the least. Spring peepers (Pseudacris crucifer) and green frogs (Rana clamitans) showed intermediate sensitivities. We concluded that chloride concentrations in ponds due to application of de-icing salts, influenced community structure by excluding salt intolerant species. - Salt toxicity is presented as a mechanism affecting the distribution of amphibians and structure of amphibian communities in roadside wetlands

  15. Current extinction rates of reptiles and amphibians.

    Science.gov (United States)

    Alroy, John

    2015-10-20

    There is broad concern that a mass extinction of amphibians and reptiles is now underway. Here I apply an extremely conservative Bayesian method to estimate the number of recent amphibian and squamate extinctions in nine important tropical and subtropical regions. The data stem from a combination of museum collection databases and published site surveys. The method computes an extinction probability for each species by considering its sighting frequency and last sighting date. It infers hardly any extinction when collection dates are randomized and it provides underestimates when artificial extinction events are imposed. The method also appears to be insensitive to trends in sampling; therefore, the counts it provides are absolute minimums. Extinctions or severe population crashes have accumulated steadily since the 1970s and 1980s, and at least 3.1% of frog species have already disappeared. Based on these data and this conservative method, the best estimate of the global grand total is roughly 200 extinctions. Consistent with previous results, frog losses are heavy in Latin America, which has been greatly affected by the pathogenic chytrid fungus Batrachochytrium dendrobatidis. Extinction rates are now four orders-of-magnitude higher than background, and at least another 6.9% of all frog species may be lost within the next century, even if there is no acceleration in the growth of environmental threats.

  16. Vitamin D in the healthy European paediatric population

    DEFF Research Database (Denmark)

    Braegger, Christian; Campoy, Cristina; Colomb, Virginie

    2013-01-01

    In recent years, reports suggesting a resurgence of vitamin D deficiency in the Western world, combined with various proposed health benefits for vitamin D supplementation have resulted in increased interest from healthcare professionals, the media and the public. The aim of this position paper...... is to summarize the published data on vitamin D intake and prevalence of vitamin D deficiency in the healthy European paediatric population, to discuss health benefits of vitamin D and to provide recommendations for the prevention of vitamin D deficiency in this population. Vitamin D plays a key role in calcium...

  17. DEMOGRAPHY AND SPATIAL POPULATION STRUCTURE IN CALIFORNIA TIGER SALAMANDER

    Science.gov (United States)

    Although the causes of many amphibian declines remain mysterious, there is general agreement that human habitat alteration represents the greatest threat to amphibian populations. In January 2000 the US Fish and Wildlife Service proposed listing Santa Barbara County California Ti...

  18. Spatial Biodiversity Patterns of Madagascar's Amphibians and Reptiles.

    Science.gov (United States)

    Brown, Jason L; Sillero, Neftali; Glaw, Frank; Bora, Parfait; Vieites, David R; Vences, Miguel

    2016-01-01

    Madagascar has become a model region for testing hypotheses of species diversification and biogeography, and many studies have focused on its diverse and highly endemic herpetofauna. Here we combine species distribution models of a near-complete set of species of reptiles and amphibians known from the island with body size data and a tabulation of herpetofaunal communities from field surveys, compiled up to 2008. Though taxonomic revisions and novel distributional records arose since compilation, we are confident that the data are appropriate for inferring and comparing biogeographic patterns among these groups of organisms. We observed species richness of both amphibians and reptiles was highest in the humid rainforest biome of eastern Madagascar, but reptiles also show areas of high richness in the dry and subarid western biomes. In several amphibian subclades, especially within the Mantellidae, species richness peaks in the central eastern geographic regions while in reptiles different subclades differ distinctly in their richness centers. A high proportion of clades and subclades of both amphibians and reptiles have a peak of local endemism in the topographically and bioclimatically diverse northern geographic regions. This northern area is roughly delimited by a diagonal spanning from 15.5°S on the east coast to ca. 15.0°S on the west coast. Amphibian diversity is highest at altitudes between 800-1200 m above sea-level whereas reptiles have their highest richness at low elevations, probably reflecting the comparatively large number of species specialized to the extended low-elevation areas in the dry and subarid biomes. We found that the range sizes of both amphibians and reptiles strongly correlated with body size, and differences between the two groups are explained by the larger body sizes of reptiles. However, snakes have larger range sizes than lizards which cannot be readily explained by their larger body sizes alone. Range filling, i.e., the amount of

  19. Spatial Biodiversity Patterns of Madagascar's Amphibians and Reptiles

    Science.gov (United States)

    Brown, Jason L.; Sillero, Neftali; Glaw, Frank; Bora, Parfait; Vieites, David R.; Vences, Miguel

    2016-01-01

    Madagascar has become a model region for testing hypotheses of species diversification and biogeography, and many studies have focused on its diverse and highly endemic herpetofauna. Here we combine species distribution models of a near-complete set of species of reptiles and amphibians known from the island with body size data and a tabulation of herpetofaunal communities from field surveys, compiled up to 2008. Though taxonomic revisions and novel distributional records arose since compilation, we are confident that the data are appropriate for inferring and comparing biogeographic patterns among these groups of organisms. We observed species richness of both amphibians and reptiles was highest in the humid rainforest biome of eastern Madagascar, but reptiles also show areas of high richness in the dry and subarid western biomes. In several amphibian subclades, especially within the Mantellidae, species richness peaks in the central eastern geographic regions while in reptiles different subclades differ distinctly in their richness centers. A high proportion of clades and subclades of both amphibians and reptiles have a peak of local endemism in the topographically and bioclimatically diverse northern geographic regions. This northern area is roughly delimited by a diagonal spanning from 15.5°S on the east coast to ca. 15.0°S on the west coast. Amphibian diversity is highest at altitudes between 800–1200 m above sea-level whereas reptiles have their highest richness at low elevations, probably reflecting the comparatively large number of species specialized to the extended low-elevation areas in the dry and subarid biomes. We found that the range sizes of both amphibians and reptiles strongly correlated with body size, and differences between the two groups are explained by the larger body sizes of reptiles. However, snakes have larger range sizes than lizards which cannot be readily explained by their larger body sizes alone. Range filling, i.e., the amount

  20. Improving the design of amphibian surveys using soil data: A case study in two wilderness areas

    Science.gov (United States)

    Bowen, K.D.; Beever, E.A.; Gafvert, U.B.

    2009-01-01

    Amphibian populations are known, or thought to be, declining worldwide. Although protected natural areas may act as reservoirs of biological integrity and serve as benchmarks for comparison with unprotected areas, they are not immune from population declines and extinctions and should be monitored. Unfortunately, identifying survey sites and performing long-term fieldwork within such (often remote) areas involves a special set of problems. We used the USDA Natural Resource Conservation Service Soil Survey Geographic (SSURGO) Database to identify, a priori, potential habitat for aquatic-breeding amphibians on North and South Manitou Islands, Sleeping Bear Dunes National Lakeshore, Michigan, and compared the results to those obtained using National Wetland Inventory (NWI) data. The SSURGO approach identified more target sites for surveys than the NWI approach, and it identified more small and ephemeral wetlands. Field surveys used a combination of daytime call surveys, night-time call surveys, and perimeter surveys. We found that sites that would not have been identified with NWI data often contained amphibians and, in one case, contained wetland-breeding species that would not have been found using NWI data. Our technique allows for easy a priori identification of numerous survey sites that might not be identified using other sources of spatial information. We recognize, however, that the most effective site identification and survey techniques will likely use a combination of methods in addition to those described here.

  1. Vertebrate animal populations of the McCormick Forest.

    Science.gov (United States)

    USDA FS

    1975-01-01

    Describes the means of surveying and estimating the populations of birds, mammals, amphibians, and reptiles in 1972 and 1973 on this 17,000-acre forest in the Upper Peninsula of Michigan. Gives an annotated list of birds and mammals and estimates biomass of amphibians in four habitats.

  2. Effects of the amphibian chytrid fungus and four insecticides on Pacific treefrogs (Pseudacris regilla)

    Science.gov (United States)

    Kleinhez, Peter; Boone, Michelle D.; Fellers, Gary

    2012-01-01

    Chemical contamination may influence host-pathogen interactions, which has implications for amphibian population declines. We examined the effects of four insecticides alone or as a mixture on development and metamorphosis of Pacific Treefrogs (Pseudacris regilla) in the presence or absence of the amphibian chytrid fungus (Batrachochytrium dendrobatidis [Bd]). Bd exposure had a negative impact on tadpole activity, survival to metamorphosis, time to metamorphosis, and time of tail absorption (with a marginally negative effect on mass at metamorphosis); however, no individuals tested positive for Bd at metamorphosis. The presence of sublethal concentrations of insecticides alone or in a mixture did not impact Pacific Treefrog activity as tadpoles, survival to metamorphosis, or time and size to metamorphosis. Insecticide exposure did not influence the effect of Bd exposure. Our study did not support our prediction that effects of Bd would be greater in the presence of expected environmental concentrations of insecticide(s), but it did show that Bd had negative effects on responses at metamorphosis that could reduce the quality of juveniles recruited into the population.

  3. Control of respiration in fish, amphibians and reptiles

    Directory of Open Access Journals (Sweden)

    E.W. Taylor

    Full Text Available Fish and amphibians utilise a suction/force pump to ventilate gills or lungs, with the respiratory muscles innervated by cranial nerves, while reptiles have a thoracic, aspiratory pump innervated by spinal nerves. However, fish can recruit a hypobranchial pump for active jaw occlusion during hypoxia, using feeding muscles innervated by anterior spinal nerves. This same pump is used to ventilate the air-breathing organ in air-breathing fishes. Some reptiles retain a buccal force pump for use during hypoxia or exercise. All vertebrates have respiratory rhythm generators (RRG located in the brainstem. In cyclostomes and possibly jawed fishes, this may comprise elements of the trigeminal nucleus, though in the latter group RRG neurons have been located in the reticular formation. In air-breathing fishes and amphibians, there may be separate RRG for gill and lung ventilation. There is some evidence for multiple RRG in reptiles. Both amphibians and reptiles show episodic breathing patterns that may be centrally generated, though they do respond to changes in oxygen supply. Fish and larval amphibians have chemoreceptors sensitive to oxygen partial pressure located on the gills. Hypoxia induces increased ventilation and a reflex bradycardia and may trigger aquatic surface respiration or air-breathing, though these latter activities also respond to behavioural cues. Adult amphibians and reptiles have peripheral chemoreceptors located on the carotid arteries and central chemoreceptors sensitive to blood carbon dioxide levels. Lung perfusion may be regulated by cardiac shunting and lung ventilation stimulates lung stretch receptors.

  4. Control of respiration in fish, amphibians and reptiles.

    Science.gov (United States)

    Taylor, E W; Leite, C A C; McKenzie, D J; Wang, T

    2010-05-01

    Fish and amphibians utilise a suction/force pump to ventilate gills or lungs, with the respiratory muscles innervated by cranial nerves, while reptiles have a thoracic, aspiratory pump innervated by spinal nerves. However, fish can recruit a hypobranchial pump for active jaw occlusion during hypoxia, using feeding muscles innervated by anterior spinal nerves. This same pump is used to ventilate the air-breathing organ in air-breathing fishes. Some reptiles retain a buccal force pump for use during hypoxia or exercise. All vertebrates have respiratory rhythm generators (RRG) located in the brainstem. In cyclostomes and possibly jawed fishes, this may comprise elements of the trigeminal nucleus, though in the latter group RRG neurons have been located in the reticular formation. In air-breathing fishes and amphibians, there may be separate RRG for gill and lung ventilation. There is some evidence for multiple RRG in reptiles. Both amphibians and reptiles show episodic breathing patterns that may be centrally generated, though they do respond to changes in oxygen supply. Fish and larval amphibians have chemoreceptors sensitive to oxygen partial pressure located on the gills. Hypoxia induces increased ventilation and a reflex bradycardia and may trigger aquatic surface respiration or air-breathing, though these latter activities also respond to behavioural cues. Adult amphibians and reptiles have peripheral chemoreceptors located on the carotid arteries and central chemoreceptors sensitive to blood carbon dioxide levels. Lung perfusion may be regulated by cardiac shunting and lung ventilation stimulates lung stretch receptors.

  5. Control of respiration in fish, amphibians and reptiles

    Directory of Open Access Journals (Sweden)

    E.W. Taylor

    2010-05-01

    Full Text Available Fish and amphibians utilise a suction/force pump to ventilate gills or lungs, with the respiratory muscles innervated by cranial nerves, while reptiles have a thoracic, aspiratory pump innervated by spinal nerves. However, fish can recruit a hypobranchial pump for active jaw occlusion during hypoxia, using feeding muscles innervated by anterior spinal nerves. This same pump is used to ventilate the air-breathing organ in air-breathing fishes. Some reptiles retain a buccal force pump for use during hypoxia or exercise. All vertebrates have respiratory rhythm generators (RRG located in the brainstem. In cyclostomes and possibly jawed fishes, this may comprise elements of the trigeminal nucleus, though in the latter group RRG neurons have been located in the reticular formation. In air-breathing fishes and amphibians, there may be separate RRG for gill and lung ventilation. There is some evidence for multiple RRG in reptiles. Both amphibians and reptiles show episodic breathing patterns that may be centrally generated, though they do respond to changes in oxygen supply. Fish and larval amphibians have chemoreceptors sensitive to oxygen partial pressure located on the gills. Hypoxia induces increased ventilation and a reflex bradycardia and may trigger aquatic surface respiration or air-breathing, though these latter activities also respond to behavioural cues. Adult amphibians and reptiles have peripheral chemoreceptors located on the carotid arteries and central chemoreceptors sensitive to blood carbon dioxide levels. Lung perfusion may be regulated by cardiac shunting and lung ventilation stimulates lung stretch receptors.

  6. Helminth parasites of amphibians from a rainforest reserve in ...

    African Journals Online (AJOL)

    Contrary to the earlier assumption that monogeneans in Nigeria were preferentially parasites of amphibians in drier environments such as the savanna, this study has shown that these parasites also infect amphibians in highly humid environments such as the rainforest. Monogeneans recorded included Metapolystoma ...

  7. Zoonotic diseases associated with reptiles and amphibians: an update.

    Science.gov (United States)

    Mitchell, Mark A

    2011-09-01

    Reptiles and amphibians are popular as pets. There are increased concerns among public health officials because of the zoonotic potential associated with these animals. Encounters with reptiles and amphibians are also on the rise in the laboratory setting and with wild animals; in both of these practices, there is also an increased likelihood for exposure to zoonotic pathogens. It is important that veterinarians remain current with the literature as it relates to emerging and reemerging zoonotic diseases attributed to reptiles and amphibians so that they can protect themselves, their staff, and their clients from potential problems.

  8. Investigation of Amphibian Mortality Events in Wildlife Reveals an On-Going Ranavirus Epidemic in the North of the Netherlands.

    Science.gov (United States)

    Rijks, Jolianne M; Saucedo, Bernardo; Spitzen-van der Sluijs, Annemarieke; Wilkie, Gavin S; van Asten, Alphons J A M; van den Broek, Jan; Boonyarittichaikij, Roschong; Stege, Marisca; van der Sterren, Fleur; Martel, An; Pasmans, Frank; Hughes, Joseph; Gröne, Andrea; van Beurden, Steven J; Kik, Marja J L

    2016-01-01

    In the four years following the first detection of ranavirus (genus Ranavirus, family Iridoviridae) infection in Dutch wildlife in 2010, amphibian mortality events were investigated nationwide to detect, characterize and map ranaviruses in amphibians over time, and to establish the affected host species and the clinico-pathological presentation of the disease in these hosts. The ultimate goal was to obtain more insight into ranavirus disease emergence and ecological risk. In total 155 dead amphibians from 52 sites were submitted between 2011 and 2014, and examined using histopathology, immunohistochemistry, virus isolation and molecular genetic characterization. Ranavirus-associated amphibian mortality events occurred at 18 sites (35%), initially only in proximity of the 2010 index site. Specimens belonging to approximately half of the native amphibian species were infected, including the threatened Pelobates fuscus (spadefoot toad). Clustered massive outbreaks involving dead adult specimens and ranavirus genomic identity indicated that one common midwife toad virus (CMTV)-like ranavirus strain is emerging in provinces in the north of the Netherlands. Modelling based on the spatiotemporal pattern of spread showed a high probability that this emerging virus will continue to be detected at new sites (the discrete reproductive power of this outbreak is 0.35). Phylogenetically distinct CMTV-like ranaviruses were found in the south of the Netherlands more recently. In addition to showing that CMTV-like ranaviruses threaten wild amphibian populations not only in Spain but also in the Netherlands, the current spread and risk of establishment reiterate that understanding the underlying causes of CMTV-like ranavirus emergence requires international attention.

  9. Investigation of Amphibian Mortality Events in Wildlife Reveals an On-Going Ranavirus Epidemic in the North of the Netherlands.

    Directory of Open Access Journals (Sweden)

    Jolianne M Rijks

    Full Text Available In the four years following the first detection of ranavirus (genus Ranavirus, family Iridoviridae infection in Dutch wildlife in 2010, amphibian mortality events were investigated nationwide to detect, characterize and map ranaviruses in amphibians over time, and to establish the affected host species and the clinico-pathological presentation of the disease in these hosts. The ultimate goal was to obtain more insight into ranavirus disease emergence and ecological risk. In total 155 dead amphibians from 52 sites were submitted between 2011 and 2014, and examined using histopathology, immunohistochemistry, virus isolation and molecular genetic characterization. Ranavirus-associated amphibian mortality events occurred at 18 sites (35%, initially only in proximity of the 2010 index site. Specimens belonging to approximately half of the native amphibian species were infected, including the threatened Pelobates fuscus (spadefoot toad. Clustered massive outbreaks involving dead adult specimens and ranavirus genomic identity indicated that one common midwife toad virus (CMTV-like ranavirus strain is emerging in provinces in the north of the Netherlands. Modelling based on the spatiotemporal pattern of spread showed a high probability that this emerging virus will continue to be detected at new sites (the discrete reproductive power of this outbreak is 0.35. Phylogenetically distinct CMTV-like ranaviruses were found in the south of the Netherlands more recently. In addition to showing that CMTV-like ranaviruses threaten wild amphibian populations not only in Spain but also in the Netherlands, the current spread and risk of establishment reiterate that understanding the underlying causes of CMTV-like ranavirus emergence requires international attention.

  10. Use of multiple dispersal pathways facilitates amphibian persistence in stream networks

    Science.gov (United States)

    Campbell, Grant E.H.; Nichols, J.D.; Lowe, W.H.; Fagan, W.F.

    2010-01-01

    Although populations of amphibians are declining worldwide, there is no evidence that salamanders occupying small streams are experiencing enigmatic declines, and populations of these species seem stable. Theory predicts that dispersal through multiple pathways can stabilize populations, preventing extinction in habitat networks. However, empirical data to support this prediction are absent for most species, especially those at risk of decline. Our mark-recapture study of stream salamanders reveals both a strong upstream bias in dispersal and a surprisingly high rate of overland dispersal to adjacent headwater streams. This evidence of route-dependent variation in dispersal rates suggests a spatial mechanism for population stability in headwater-stream salamanders. Our results link the movement behavior of stream salamanders to network topology, and they underscore the importance of identifying and protecting critical dispersal pathways when addressing region-wide population declines.

  11. Use of multiple dispersal pathways facilitates amphibian persistence in stream networks.

    Science.gov (United States)

    Campbell Grant, Evan H; Nichols, James D; Lowe, Winsor H; Fagan, William F

    2010-04-13

    Although populations of amphibians are declining worldwide, there is no evidence that salamanders occupying small streams are experiencing enigmatic declines, and populations of these species seem stable. Theory predicts that dispersal through multiple pathways can stabilize populations, preventing extinction in habitat networks. However, empirical data to support this prediction are absent for most species, especially those at risk of decline. Our mark-recapture study of stream salamanders reveals both a strong upstream bias in dispersal and a surprisingly high rate of overland dispersal to adjacent headwater streams. This evidence of route-dependent variation in dispersal rates suggests a spatial mechanism for population stability in headwater-stream salamanders. Our results link the movement behavior of stream salamanders to network topology, and they underscore the importance of identifying and protecting critical dispersal pathways when addressing region-wide population declines.

  12. Spatial and temporal variation in radiation exposure of amphibians - Implications for environmental risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Stark, K. [Stockholm University (Sweden)

    2014-07-01

    Although amphibians are threatened world-wide, many amphibian species are protected in national legislation. Thus, amphibians need special attention in many environmental risk assessments for releases of contaminants such as radionuclides. In fact, amphibians' ecology and physiology (including, for example, a complex life-cycle with both aquatic and terrestrial life stages, and a thin skin) makes them sensitive to radiation exposure. In current dose models for wildlife, homogenous distribution of radionuclides in soil is assumed. However, soils are heterogeneous environments and radionuclide contamination can be very unevenly distributed. As a consequence, bioaccumulation of radionuclides in biota may vary on a local scale. Specifically, organisms' spatial location and movement within habitats may affect both their external and internal exposure pattern to radionuclides. Therefore, measuring the spatial location of individual amphibians within ecosystems and understanding why they use these different locations is essential for predicting potential effects of released radionuclides on these populations. The aim of this study was to investigate amphibians' spatial distribution in a {sup 137}Cs contaminated wetland area and their body content of {sup 137}Cs at the beginning and end of the summer period. The study site was a wetland nature reserve called Bladmyra near Gaevle in the central-eastern part of Sweden. This area received fallout of {sup 137}Cs after the Chernobyl accident in 1986. This study measured the spatial distributions of two amphibian species (Rana arvalis and Bufo bufo) with Passive Integrated Transponder (PIT) tags in a mark-and-recapture study during 2012-2014. In addition, {sup 137}Cs body content in the two species was measured by whole body counting in spring and autumn of 2013. The results showed differences between years in how marked animals used the study area: More individuals stayed in a small area during 2012 than in 2013

  13. Acid precipitation studies in Colorado and Wyoming: interim report of surveys of montane amphibians and water chemistry

    Science.gov (United States)

    Corn, Paul Stephen; Stolzenburg, William; Bury, R. Bruce

    1989-01-01

    Acid deposition may be detrimental or stressful to native populations of wildlife. Because many species of amphibians breed in shallow ponds created by spring rains or melting snow, they may be particularly vulnerable to the effects of acidification. From 1986 to 1988, we surveyed 105 locations in the central Rocky Mountains where amphibians had been recorded previously, and we found that two species of amphibians had experiences major losses. We found the northern leopard frog (Rana pipiens) at only 4 of 33 (12%) historically known localities, and the boreal toad (Bufo boreas) was present at 10 of 59 (17%) known localities. Three other species have not suffered region-wide declines. Tiger salamanders (Ambystoma tigrinum) and wood frogs (Rana sylvatica) were present at 45% and 69% of known localities respectively, and were observed at several localities were they had not been recorded previously. Chorus frogs (Pseudacris triseriata) suffered a catastrophic decline in population size in one population monitored since 1961, but regionally, this species was observed in 36 of 56 (64%) known localities and in another 19 localities where there were no previous records. Complete water chemistry was recorded for 41 localities, and pH was measured at 110 sites in total. Acid neutralizing capacity, pH, specific conductivity, and cation concentrations were negatively correlated with elevation. However, in mountain ponds and lakes, pH was rarely less than 6.0 during the amphibian breeding season. We tested the tolerance of embryos of the four species of frogs to low pH. The LC50 pH was 4.8 for chorus frogs, 4.4-4.7 for leopard frogs, 4.4-4.5 for boreal toads, and 4.2-4.3 for wood frogs. Survival of wood frog embryos declined when exposed to aluminum concentrations of 100 µg/L or greater, but boreal toad embryos survived exposure to aluminum concentrations of 400 µg/L. Acid deposition does not appear to be a major factor in the decline of leopard frogs and boreal toads

  14. Quantitative evidence for the effects of multiple drivers on continental-scale amphibian declines

    Science.gov (United States)

    Grant, Evan H. Campbell; Miller, David A. W.; Schmidt, Benedikt R.; Adams, Michael J.; Amburgey, Staci M.; Chambert, Thierry A.; Cruickshank, Sam S.; Fisher, Robert N.; Green, David M.; Hossack, Blake R.; Johnson, Pieter T.J.; Joseph, Maxwell B.; Rittenhouse, Tracy A. G.; Ryan, Maureen E.; Waddle, J. Hardin; Walls, Susan C.; Bailey, Larissa L.; Fellers, Gary M.; Gorman, Thomas A.; Ray, Andrew M.; Pilliod, David S.; Price, Steven J.; Saenz, Daniel; Sadinski, Walt; Muths, Erin L.

    2016-01-01

    Since amphibian declines were first proposed as a global phenomenon over a quarter century ago, the conservation community has made little progress in halting or reversing these trends. The early search for a “smoking gun” was replaced with the expectation that declines are caused by multiple drivers. While field observations and experiments have identified factors leading to increased local extinction risk, evidence for effects of these drivers is lacking at large spatial scales. Here, we use observations of 389 time-series of 83 species and complexes from 61 study areas across North America to test the effects of 4 of the major hypothesized drivers of declines. While we find that local amphibian populations are being lost from metapopulations at an average rate of 3.79% per year, these declines are not related to any particular threat at the continental scale; likewise the effect of each stressor is variable at regional scales. This result - that exposure to threats varies spatially, and populations vary in their response - provides little generality in the development of conservation strategies. Greater emphasis on local solutions to this globally shared phenomenon is needed.

  15. Amphibian diversity in Shimba Hills National Reserve, Kenya: A ...

    African Journals Online (AJOL)

    We present the first annotated amphibian checklist of Shimba Hills National Reserve (SHNR). The list comprises of 30 currently known amphibians (28 anurans and two caecilians), which includes 11 families and 15 genera. In addition, individual records per species, distribution in the reserve and brief remarks about the ...

  16. The potential effects of climate change on amphibian distribution, range fragmentation and turnover in China.

    Science.gov (United States)

    Duan, Ren-Yan; Kong, Xiao-Quan; Huang, Min-Yi; Varela, Sara; Ji, Xiang

    2016-01-01

    Many studies predict that climate change will cause species movement and turnover, but few have considered the effect of climate change on range fragmentation for current species and/or populations. We used MaxEnt to predict suitable habitat, fragmentation and turnover for 134 amphibian species in China under 40 future climate change scenarios spanning four pathways (RCP2.6, RCP4.5, RCP6 and RCP8.5) and two time periods (the 2050s and 2070s). Our results show that climate change may cause a major shift in spatial patterns of amphibian diversity. Amphibians in China would lose 20% of their original ranges on average; the distribution outside current ranges would increase by 15%. Suitable habitats for over 90% of species will be located in the north of their current range, for over 95% of species in higher altitudes (from currently 137-4,124 m to 286-4,396 m in the 2050s or 314-4,448 m in the 2070s), and for over 75% of species in the west of their current range. Also, our results predict two different general responses to the climate change: some species contract their ranges while moving westwards, southwards and to higher altitudes, while others expand their ranges. Finally, our analyses indicate that range dynamics and fragmentation are related, which means that the effects of climate change on Chinese amphibians might be two-folded.

  17. The potential effects of climate change on amphibian distribution, range fragmentation and turnover in China

    Directory of Open Access Journals (Sweden)

    Ren-Yan Duan

    2016-07-01

    Full Text Available Many studies predict that climate change will cause species movement and turnover, but few have considered the effect of climate change on range fragmentation for current species and/or populations. We used MaxEnt to predict suitable habitat, fragmentation and turnover for 134 amphibian species in China under 40 future climate change scenarios spanning four pathways (RCP2.6, RCP4.5, RCP6 and RCP8.5 and two time periods (the 2050s and 2070s. Our results show that climate change may cause a major shift in spatial patterns of amphibian diversity. Amphibians in China would lose 20% of their original ranges on average; the distribution outside current ranges would increase by 15%. Suitable habitats for over 90% of species will be located in the north of their current range, for over 95% of species in higher altitudes (from currently 137–4,124 m to 286–4,396 m in the 2050s or 314–4,448 m in the 2070s, and for over 75% of species in the west of their current range. Also, our results predict two different general responses to the climate change: some species contract their ranges while moving westwards, southwards and to higher altitudes, while others expand their ranges. Finally, our analyses indicate that range dynamics and fragmentation are related, which means that the effects of climate change on Chinese amphibians might be two-folded.

  18. Uses and Doses of Local Anesthetics in Fish, Amphibians, and Reptiles.

    Science.gov (United States)

    Chatigny, Frederic; Kamunde, Collins; Creighton, Catherine M; Stevens, E Don

    2017-05-01

    Local anesthetics are an integral part of routine pain management in mammals, yet their use is relatively limited in fish, amphibians and reptiles. These animals frequently undergo potentially painful surgical procedures and therefore could possibly benefit from those drugs. Some recommendations are currently available in the literature concerning analgesic use in these animals. However the pharmacological properties, safety and often efficacy of local anesthetic drugs have not been investigated yet in fish, amphibians, or reptiles. This review compiled current information concerning the use of those agents in fish, reptiles and amphibians to help clinicians make an informed decision as to which dose and drug to use. The resulting literature search showed that the literature concerning use of local analgesics in fish and amphibians is very limited while the literature for reptiles is more extensive. We found few experimental studies evaluating the efficacy of local anesthetics. Further studies would provide additional information for developing guidelines to improve the welfare of fish, amphibians and reptiles.

  19. Patterns of Assemblage Structure Indicate a Broader Conservation Potential of Focal Amphibians for Pond Management.

    Directory of Open Access Journals (Sweden)

    Elin Soomets

    Full Text Available Small freshwater ponds host diverse and vulnerable biotic assemblages but relatively few conspicuous, specially protected taxa. In Europe, the amphibians Triturus cristatus and Pelobates fuscus are among a few species whose populations have been successfully restored using pond restoration and management activities at the landscape scale. In this study, we explored whether the ponds constructed for those two target species have wider conservation significance, particularly for other species of conservation concern. We recorded the occurrence of amphibians and selected aquatic macro-invertebrates (dragonflies; damselflies; diving beetles; water scavenger beetles in 66 ponds specially constructed for amphibians (up to 8 years post construction and, for comparison, in 100 man-made ponds (created by local people for cattle or garden watering, peat excavation, etc. and 65 natural ponds in Estonia. We analysed nestedness of the species assemblages and its dependence on the environment, and described the co-occurrence patterns between the target amphibians and other aquatic species. The assemblages in all ponds were significantly nested, but the environmental determinants of nestedness and co-occurrence of particular species differed among pond types. Constructed ponds were most species-rich irrespective of the presence of the target species; however, T. cristatus was frequent in those ponds and rare elsewhere, and it showed nested patterns in every type of pond. We thus conclude that pond construction for the protected amphibians can serve broader habitat conservation aims in the short term. However, the heterogeneity and inconsistent presence of species of conservation concern observed in other types of ponds implies that long-term perspectives on pond management require more explicit consideration of different habitat and biodiversity values. We also highlight nestedness analysis as a tool that can be used for the practical task of selecting focal

  20. Amphibians and Reptiles of Los Alamos County

    Energy Technology Data Exchange (ETDEWEB)

    Teralene S. Foxx; Timothy K. Haarmann; David C. Keller

    1999-10-01

    Recent studies have shown that amphibians and reptiles are good indicators of environmental health. They live in terrestrial and aquatic environments and are often the first animals to be affected by environmental change. This publication provides baseline information about amphibians and reptiles that are present on the Pajarito Plateau. Ten years of data collection and observations by researchers at Los Alamos National Laboratory, the University of New Mexico, the New Mexico Department of Game and Fish, and hobbyists are represented.

  1. New distributional records of amphibians and reptiles from northern Oaxaca, México

    OpenAIRE

    González, Cynthia; Brenis, Ángel; Arrazola, Teresa

    2014-01-01

    During 2011 we performed a microregional inventory of amphibians and reptiles from the south-central region of the Papaloapan basin in northern Oaxaca. We recorded one amphibian species previously unknown in the state, and recorded range extensions for two additional amphibian and four reptile species. This increases the known herpetofauna of Oaxaca to 378 species.

  2. The cause of global amphibian declines: a developmental endocrinologist's perspective.

    Science.gov (United States)

    Hayes, T B; Falso, P; Gallipeau, S; Stice, M

    2010-03-15

    Greater than 70% of the world's amphibian species are in decline. We propose that there is probably not a single cause for global amphibian declines and present a three-tiered hierarchical approach that addresses interactions among and between ultimate and proximate factors that contribute to amphibian declines. There are two immediate (proximate) causes of amphibian declines: death and decreased recruitment (reproductive failure). Although much attention has focused on death, few studies have addressed factors that contribute to declines as a result of failed recruitment. Further, a great deal of attention has focused on the role of pathogens in inducing diseases that cause death, but we suggest that pathogen success is profoundly affected by four other ultimate factors: atmospheric change, environmental pollutants, habitat modification and invasive species. Environmental pollutants arise as likely important factors in amphibian declines because they have realized potential to affect recruitment. Further, many studies have documented immunosuppressive effects of pesticides, suggesting a role for environmental contaminants in increased pathogen virulence and disease rates. Increased attention to recruitment and ultimate factors that interact with pathogens is important in addressing this global crisis.

  3. Selecting for extinction: nonrandom disease-associated extinction homogenizes amphibian biotas.

    Science.gov (United States)

    Smith, Kevin G; Lips, Karen R; Chase, Jonathan M

    2009-10-01

    Studying the patterns in which local extinctions occur is critical to understanding how extinctions affect biodiversity at local, regional and global spatial scales. To understand the importance of patterns of extinction at a regional spatial scale, we use data from extirpations associated with a widespread pathogenic agent of amphibian decline, Batrachochytrium dendrobatidis (Bd) as a model system. We apply novel null model analyses to these data to determine whether recent extirpations associated with Bd have resulted in selective extinction and homogenization of diverse tropical American amphibian biotas. We find that Bd-associated extinctions in this region were nonrandom and disproportionately, but not exclusively, affected low-occupancy and endemic species, resulting in homogenization of the remnant amphibian fauna. The pattern of extirpations also resulted in phylogenetic homogenization at the family level and ecological homogenization of reproductive mode and habitat association. Additionally, many more species were extirpated from the region than would be expected if extirpations occurred randomly. Our results indicate that amphibian declines in this region are an extinction filter, reducing regional amphibian biodiversity to highly similar relict assemblages and ultimately causing amplified biodiversity loss at regional and global scales.

  4. Does fire affect amphibians and reptiles in eastern U.S. oak forests?

    Science.gov (United States)

    Rochelle B. Renken

    2006-01-01

    Current information about the effect of fire on amphibians and reptiles in oak forests of the Eastern and Central United States is reviewed. Current data suggest that fire results in little direct mortality of amphibians and reptiles. Fire has no effect on overall amphibian abundance, diversity, and number of species in comparisons of burned and unburned plots, though...

  5. Cryopreservation and other assisted reproductive technologies for the conservation of threatened amphibians and reptiles: bringing the ARTs up to speed.

    Science.gov (United States)

    Clulow, John; Clulow, Simon

    2016-06-01

    Amphibians and reptiles are experiencing serious declines, with the number of threatened species and extinctions growing rapidly as the modern biodiversity crisis unfolds. For amphibians, the panzootic of chytridiomycosis is a major driver. For reptiles, habitat loss and harvesting from the wild are key threats. Cryopreservation and other assisted reproductive technologies (ARTs) could play a role in slowing the loss of amphibian and reptile biodiversity and managing threatened populations through genome storage and the production of live animals from stored material. These vertebrate classes are at different stages of development in cryopreservation and other ARTs, and each class faces different technical challenges arising from the separate evolutionary end-points of their reproductive biology. For amphibians, the generation of live offspring from cryopreserved spermatozoa has been achieved, but the cryopreservation of oocytes and embryos remains elusive. With reptiles, spermatozoa have been cryopreserved in a few species, but no offspring from cryopreserved spermatozoa have been reported, and the generation of live young from AI has only occurred in a small number of species. Cryopreservation and ARTs are more developed and advanced for amphibians than reptiles. Future work on both groups needs to concentrate on achieving proof of concept examples that demonstrate the use of genome storage and ARTs in successfully recovering threatened species to increase awareness and support for this approach to conservation.

  6. Common procedures in reptiles and amphibians.

    Science.gov (United States)

    de la Navarre, Byron J S

    2006-05-01

    Reptiles and amphibians continue to be popular as pets in the United States and throughout the world. It therefore behooves veterinarians interested in caring for these exotic species to continually gather knowledge concerning both their proper husbandry and the conditions that require medical and/or surgical intervention. This article covers husbandry, physical examination, and clinical and diagnostic techniques in an effort to present guidelines for the evaluation of the reptile or amphibian patient. Gathering clinical data will aid veterinarians in arriving at the proper diagnosis,increasing the chances of success with treatment protocols, and educating the clients in proper nutrition and husbandry for their pets.

  7. JP-3 gene polymorphism in a healthy population of Serbia and ...

    Indian Academy of Sciences (India)

    Unknown

    sions are the cause of Huntington disease like-2 (HDL-2) phenotype. CTG repeats in ... Analyses of CTG repeat polymorphism of JP-3 gene in various healthy populations could help in estimating ... of a recently described membrane protein family exclu- .... low frequency of larger alleles in German population based on very ...

  8. [Nested species subsets of amphibians and reptiles in Thousand Island Lake].

    Science.gov (United States)

    Wang, Xi; Wang, Yan-Ping; Ding, Ping

    2012-10-01

    Habitat fragmentation is a main cause for the loss of biological diversity. Combining line-transect methods to survey the amphibians and reptiles on 23 islands on Thousand Island Lake in Zhejiang province, along with survey data on nearby plant species and habitat variables collected by GIS, we used the"BINMATNEST (binary matrix nestedness temperature calculator)" software and the Spearman rank correlation to examine whether amphibians and reptiles followed nested subsets and their influencing factors. The results showed that amphibians and reptiles were significantly nested, and that the island area and habitat type were significantly associated with their nested ranks. Therefore, to effectively protect amphibians and reptiles in the Thousand Islands Lake area we should pay prior attention to islands with larger areas and more habitat types.

  9. Impacts of road deicing salt on the demography of vernal pool-breeding amphibians.

    Science.gov (United States)

    Karraker, Nancy E; Gibbs, James P; Vonesh, James R

    2008-04-01

    Deicing agents, primarily road salt, are applied to roads in 26 states in the United States and in a number of European countries, yet the scale of impacts of road salt on aquatic organisms remains largely under-studied. The issue is germane to amphibian conservation because both adult and larval amphibians are known to be particularly sensitive to changes in their osmolar environments. In this study, we combined survey, experimental, and demographic modeling approaches to evaluate the possible effects of road salt on two common vernal-pond-breeding amphibian species, the spotted salamander (Ambystoma maculatum) and the wood frog (Rana sylvatica). We found that in the Adirondack Mountain Region of New York (USA), road salt traveled up to 172 m from the highway into wetlands. Surveys showed that egg mass densities of spotted salamanders (A. maculatum) and wood frogs (R. sylvatica) were two times higher in forest pools than roadside pools, but this pattern was better explained by road proximity than by increased salinity. Experiments demonstrated that embryonic and larval survival were reduced at moderate (500 muS) and high conductivities (3000 muS) in A. maculatum and at high conductivities in R. sylvatica. Demographic models suggest that such egg and larval stage effects of salt may have important impacts on populations near roads, particularly in the case of A. maculatum, for which salt exposure may lead to local extinction. For both species, the effect of road salt was dependent upon the strength of larval density dependence and declined rapidly with distance from the roadside, with the greatest negative effects being limited to within 50 m. Based on this evidence, we argue that efforts to protect local populations of A. maculatum and R. sylvatica in roadside wetlands should, in part, be aimed at reducing application of road salt near wetlands with high conductivity levels.

  10. Reproduction, Embryonic Development, and Maternal Transfer of Contaminants in the Amphibian Gastrophryne carolinensis

    OpenAIRE

    Hopkins, William Alexander; DuRant, Sarah Elizabeth; Staub, Brandon Patrick; Rowe, Christopher Lee; Jackson, Brian Phillip

    2005-01-01

    Although many amphibian populations around the world are declining at alarming rates, the cause of most declines remains unknown. Environmental contamination is one of several factors implicated in declines and may have particularly important effects on sensitive developmental stages. Despite the severe effects of maternal transfer of contaminants on early development in other vertebrate lineages, no studies have examined the effects of maternal transfer of contaminants on reproduction or dev...

  11. A Place to Call Home: Amphibian Use of Created and Restored Wetlands

    Directory of Open Access Journals (Sweden)

    Donald J. Brown

    2012-01-01

    Full Text Available Loss and degradation of wetland habitats are major contributing factors to the global decline of amphibians. Creation and restoration of wetlands could be a valuable tool for increasing local amphibian species richness and abundance. We synthesized the peer-reviewed literature addressing amphibian use of created and restored wetlands, focusing on aquatic habitat, upland habitat, and wetland connectivity and configuration. Amphibian species richness or abundance at created and restored wetlands was either similar to or greater than reference wetlands in 89% of studies. Use of created and restored wetlands by individual species was driven by aquatic and terrestrial habitat preferences, as well as ability to disperse from source wetlands. We conclude that creating and restoring wetlands can be valuable tools for amphibian conservation. However, the ecological needs and preferences of target species must be considered to maximize the potential for successful colonization and long-term persistence.

  12. The Emerging Amphibian Fungal Disease, Chytridiomycosis: A Key Example of the Global Phenomenon of Wildlife Emerging Infectious Diseases.

    Science.gov (United States)

    Kolby, Jonathan E; Daszak, Peter

    2016-06-01

    The spread of amphibian chytrid fungus, Batrachochytrium dendrobatidis, is associated with the emerging infectious wildlife disease chytridiomycosis. This fungus poses an overwhelming threat to global amphibian biodiversity and is contributing toward population declines and extinctions worldwide. Extremely low host-species specificity potentially threatens thousands of the 7,000+ amphibian species with infection, and hosts in additional classes of organisms have now also been identified, including crayfish and nematode worms.Soon after the discovery of B. dendrobatidis in 1999, it became apparent that this pathogen was already pandemic; dozens of countries and hundreds of amphibian species had already been exposed. The timeline of B. dendrobatidis's global emergence still remains a mystery, as does its point of origin. The reason why B. dendrobatidis seems to have only recently increased in virulence to catalyze this global disease event remains unknown, and despite 15 years of investigation, this wildlife pandemic continues primarily uncontrolled. Some disease treatments are effective on animals held in captivity, but there is currently no proven method to eradicate B. dendrobatidis from an affected habitat, nor have we been able to protect new regions from exposure despite knowledge of an approaching "wave" of B. dendrobatidis and ensuing disease.International spread of B. dendrobatidis is largely facilitated by the commercial trade in live amphibians. Chytridiomycosis was recently listed as a globally notifiable disease by the World Organization for Animal Health, but few countries, if any, have formally adopted recommended measures to control its spread. Wildlife diseases continue to emerge as a consequence of globalization, and greater effort is urgently needed to protect global health.

  13. Amphibian chytridiomycosis: a review with focus on fungus-host interactions.

    Science.gov (United States)

    Van Rooij, Pascale; Martel, An; Haesebrouck, Freddy; Pasmans, Frank

    2015-11-25

    Amphibian declines and extinctions are emblematic for the current sixth mass extinction event. Infectious drivers of these declines include the recently emerged fungal pathogens Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans (Chytridiomycota). The skin disease caused by these fungi is named chytridiomycosis and affects the vital function of amphibian skin. Not all amphibians respond equally to infection and host responses might range from resistant, over tolerant to susceptible. The clinical outcome of infection is highly dependent on the amphibian host, the fungal virulence and environmental determinants. B. dendrobatidis infects the skin of a large range of anurans, urodeles and caecilians, whereas to date the host range of B. salamandrivorans seems limited to urodeles. So far, the epidemic of B. dendrobatidis is mainly limited to Australian, neotropical, South European and West American amphibians, while for B. salamandrivorans it is limited to European salamanders. Other striking differences between both fungi include gross pathology and thermal preferences. With this review we aim to provide the reader with a state-of-the art of host-pathogen interactions for both fungi, in which new data pertaining to the interaction of B. dendrobatidis and B. salamandrivorans with the host's skin are integrated. Furthermore, we pinpoint areas in which more detailed studies are necessary or which have not received the attention they merit.

  14. Calling phenology of a diverse amphibian assemblage in response to meteorological conditions

    Science.gov (United States)

    Plenderleith, T. Lynette; Stratford, Danial; Lollback, Gregory W.; Chapple, David G.; Reina, Richard D.; Hero, Jean-Marc

    2017-12-01

    The strong association between amphibian activity, breeding and recruitment with local environmental conditions raises concerns regarding how changes in climate may affect the persistence of species populations into the future. Additionally, in a highly diverse assemblage of anurans, competition for breeding sites affects the time and duration of activity, as species compete for limited resources such as water. Meteorological conditions are strong drivers of amphibian activity, so we assessed whether temperature, rainfall, atmospheric pressure and humidity were associated with the calling phenology of an assemblage of anurans in South East Queensland, Australia. We performed calling surveys and collected digital recordings at 45 ponds in an area known for high anuran diversity. We performed detection analyses to investigate the influence of 10 meteorological variables in detection of calling activity in 19 amphibian species. Our results suggest four breeding strategies in the assemblage: explosive summer breeders, prolonged breeders, opportunistic breeders and a winter breeder. Classifying these species into associations provides a framework for understanding how species respond to environmental conditions. Explosive breeders (i.e. species demonstrating short and highly synchronised breeding periods) were particularly responsive to temperature. Our findings help elucidate the breeding phenology of frogs and provide valuable information on their mating systems in native Australian forests. This study highlights the difficulties of surveying even common anurans. We highlight the importance of predictability and stability in climate and the vulnerability of species for which reproduction appears to require highly specific environmental cues.

  15. Calling phenology of a diverse amphibian assemblage in response to meteorological conditions

    Science.gov (United States)

    Plenderleith, T. Lynette; Stratford, Danial; Lollback, Gregory W.; Chapple, David G.; Reina, Richard D.; Hero, Jean-Marc

    2018-05-01

    The strong association between amphibian activity, breeding and recruitment with local environmental conditions raises concerns regarding how changes in climate may affect the persistence of species populations into the future. Additionally, in a highly diverse assemblage of anurans, competition for breeding sites affects the time and duration of activity, as species compete for limited resources such as water. Meteorological conditions are strong drivers of amphibian activity, so we assessed whether temperature, rainfall, atmospheric pressure and humidity were associated with the calling phenology of an assemblage of anurans in South East Queensland, Australia. We performed calling surveys and collected digital recordings at 45 ponds in an area known for high anuran diversity. We performed detection analyses to investigate the influence of 10 meteorological variables in detection of calling activity in 19 amphibian species. Our results suggest four breeding strategies in the assemblage: explosive summer breeders, prolonged breeders, opportunistic breeders and a winter breeder. Classifying these species into associations provides a framework for understanding how species respond to environmental conditions. Explosive breeders (i.e. species demonstrating short and highly synchronised breeding periods) were particularly responsive to temperature. Our findings help elucidate the breeding phenology of frogs and provide valuable information on their mating systems in native Australian forests. This study highlights the difficulties of surveying even common anurans. We highlight the importance of predictability and stability in climate and the vulnerability of species for which reproduction appears to require highly specific environmental cues.

  16. Cognitive-enhancing drugs in the healthy population: Fundamental drawbacks and researcher roles

    Directory of Open Access Journals (Sweden)

    Tsee Leng Choy

    2015-12-01

    Full Text Available The use of pharmacological cognitive enhancers (PCEs in the healthy population is a controversial topic with numerous and expansive repercussions. By outlining common proponent arguments on the current PCE state of affairs, the definition of normality, and the complex regulation of PCEs, this article addresses why the mainstream use of PCEs in the healthy population is still disadvantageous overall. In this respect, the influence and roles of researchers to the society are emphasized in bringing the focus back to the fundamental issues, which is crucial in deciphering its controversy and avoiding costly societal, research credibility and ethical implications.

  17. Evaluating Ultraviolet Radiation Exposures Determined from TOMS Satellite Data at Sites of Amphibian Declines in Central and South America

    Science.gov (United States)

    Middleton, Elizabeth M.; Smith, David E. (Technical Monitor)

    2000-01-01

    Many amphibian species have experienced substantial population declines, or have disappeared altogether, during the last several decades at a number of amphibian census sites in Central and South America. This study addresses the use of satellite-derived trends in solar ultraviolet-B (UV-B; 280-320 nm) radiation exposures at these sites over the last two decades, and is intended to demonstrate a role for satellite observations in determining whether UV-B radiation is a contributing factor in amphibian declines. UV-B radiation levels at the Earth's surface were derived from the Total Ozone Mapping Spectrometer (TOMS) satellite data, typically acquired daily since 1979. These data were used to calculate the daily erythemal (sunburning) UV-B, or UV-B(sub ery), exposures at the latitude, longitude, and elevation of each of 20 census sites. The annually averaged UV-B(sub ery) dose, as well as the maximum values, have been increasing in both Central and South America, with higher levels received at the Central American sites. The annually averaged UV-B(sub ery) exposures increased significantly from 1979-1998 at all 11 Central American sites examined (r(exp 2) = 0.60 - 0.79; P= 6750 J/sq m*d) to the annual UV-B(sub ery) total has increased from approx. 5% to approx. 15% in Central America over the 19 year period, but actual daily exposures for each species are unknown. Synergy among UV-B radiation and other factors, especially those associated with alterations of water chemistry (e.g., acidification) in aqueous habitats is discussed. These findings justify further research concerning whether UV-B(sub ery) radiation plays a role in amphibian population declines and extinctions.

  18. Measuring the meltdown: drivers of global amphibian extinction and decline.

    Directory of Open Access Journals (Sweden)

    Navjot S Sodhi

    Full Text Available Habitat loss, climate change, over-exploitation, disease and other factors have been hypothesised in the global decline of amphibian biodiversity. However, the relative importance of and synergies among different drivers are still poorly understood. We present the largest global analysis of roughly 45% of known amphibians (2,583 species to quantify the influences of life history, climate, human density and habitat loss on declines and extinction risk. Multi-model Bayesian inference reveals that large amphibian species with small geographic range and pronounced seasonality in temperature and precipitation are most likely to be Red-Listed by IUCN. Elevated habitat loss and human densities are also correlated with high threat risk. Range size, habitat loss and more extreme seasonality in precipitation contributed to decline risk in the 2,454 species that declined between 1980 and 2004, compared to species that were stable (n = 1,545 or had increased (n = 28. These empirical results show that amphibian species with restricted ranges should be urgently targeted for conservation.

  19. Measuring the meltdown: drivers of global amphibian extinction and decline.

    Science.gov (United States)

    Sodhi, Navjot S; Bickford, David; Diesmos, Arvin C; Lee, Tien Ming; Koh, Lian Pin; Brook, Barry W; Sekercioglu, Cagan H; Bradshaw, Corey J A

    2008-02-20

    Habitat loss, climate change, over-exploitation, disease and other factors have been hypothesised in the global decline of amphibian biodiversity. However, the relative importance of and synergies among different drivers are still poorly understood. We present the largest global analysis of roughly 45% of known amphibians (2,583 species) to quantify the influences of life history, climate, human density and habitat loss on declines and extinction risk. Multi-model Bayesian inference reveals that large amphibian species with small geographic range and pronounced seasonality in temperature and precipitation are most likely to be Red-Listed by IUCN. Elevated habitat loss and human densities are also correlated with high threat risk. Range size, habitat loss and more extreme seasonality in precipitation contributed to decline risk in the 2,454 species that declined between 1980 and 2004, compared to species that were stable (n = 1,545) or had increased (n = 28). These empirical results show that amphibian species with restricted ranges should be urgently targeted for conservation.

  20. Patterns and biases in climate change research on amphibians and reptiles: a systematic review.

    Science.gov (United States)

    Winter, Maiken; Fiedler, Wolfgang; Hochachka, Wesley M; Koehncke, Arnulf; Meiri, Shai; De la Riva, Ignacio

    2016-09-01

    Climate change probably has severe impacts on animal populations, but demonstrating a causal link can be difficult because of potential influences by additional factors. Assessing global impacts of climate change effects may also be hampered by narrow taxonomic and geographical research foci. We review studies on the effects of climate change on populations of amphibians and reptiles to assess climate change effects and potential biases associated with the body of work that has been conducted within the last decade. We use data from 104 studies regarding the effect of climate on 313 species, from 464 species-study combinations. Climate change effects were reported in 65% of studies. Climate change was identified as causing population declines or range restrictions in half of the cases. The probability of identifying an effect of climate change varied among regions, taxa and research methods. Climatic effects were equally prevalent in studies exclusively investigating climate factors (more than 50% of studies) and in studies including additional factors, thus bolstering confidence in the results of studies exclusively examining effects of climate change. Our analyses reveal biases with respect to geography, taxonomy and research question, making global conclusions impossible. Additional research should focus on under-represented regions, taxa and questions. Conservation and climate policy should consider the documented harm climate change causes reptiles and amphibians.

  1. Advective and diffusive dermal processes for estimating terrestrial amphibian pesticide exposure

    Science.gov (United States)

    Background/Question/Methods Dermal exposure presents a potentially significant but understudied route for pesticide uptake in terrestrial amphibians. Historically, evaluation of pesticide risk to both amphibians and reptiles has been achieved by comparing ingestion and inhalat...

  2. Modeling amphibian energetics, habitat suitability, and movements of western toads, Anaxyrus (=Bufo) boreas, across present and future landscapes

    Science.gov (United States)

    Bartelt, Paul E.; Klaver, Robert W.; Porter, Warren P.

    2010-01-01

    Effective conservation of amphibian populations requires the prediction of how amphibians use and move through a landscape. Amphibians are closely coupled to their physical environment. Thus an approach that uses the physiological attributes of amphibians, together with knowledge of their natural history, should be helpful. We used Niche Mapper™ to model the known movements and habitat use patterns of a population of Western toads (Anaxyrus (=Bufo) boreas) occupying forested habitats in southeastern Idaho. Niche Mapper uses first principles of environmental biophysics to combine features of topography, climate, land cover, and animal features to model microclimates and animal physiology and behavior across landscapes. Niche Mapper reproduced core body temperatures (Tc) and evaporation rates of live toads with average errors of 1.6 ± 0.4 °C and 0.8 ± 0.2 g/h, respectively. For four different habitat types, it reproduced similar mid-summer daily temperature patterns as those measured in the field and calculated evaporation rates (g/h) with an average error rate of 7.2 ± 5.5%. Sensitivity analyses indicate these errors do not significantly affect estimates of food consumption or activity. Using Niche Mapper we predicted the daily habitats used by free-ranging toads; our accuracy for female toads was greater than for male toads (74.2 ± 6.8% and 53.6 ± 15.8%, respectively), reflecting the stronger patterns of habitat selection among females. Using these changing to construct a cost surface, we also reconstructed movement paths that were consistent with field observations. The effect of climate warming on toads depends on the interaction of temperature and atmospheric moisture. If climate change occurs as predicted, results from Niche Mapper suggests that climate warming will increase the physiological cost of landscapes thereby limiting the activity for toads in different habitats.

  3. Amphibians and Reptiles of the state of Nuevo Le?n, Mexico

    OpenAIRE

    Lemos-Espinal, Julio A.; Smith, Geoffrey R.; Cruz, Alexander

    2016-01-01

    Abstract We compiled a check list of the herpetofauna of Nuevo Le?n. We documented 132 species (23 amphibians, 109 reptiles), representing 30 families (11 amphibians, 19 reptiles) and 73 genera (17 amphibians, 56 reptiles). Only two species are endemic to Nuevo Le?n. Nuevo Le?n contains a relatively high richness of lizards in the genus Sceloporus . Overlap in the herpetofauna of Nuevo Le?n and states it borders is fairly extensive. Of 130 native species, 102 are considered species of Least C...

  4. Self-transcendence and correlates in a healthy population.

    Science.gov (United States)

    Coward, D D

    1996-01-01

    The purpose of this study was to document the presence of self-transcendence perspectives in a healthy population and to compare self-transcendence and related concepts with previous findings in elderly well persons and in those with life-threatening illness. Levels of self-transcendence, as assessed by the Self-Transcendence Scale and the Purpose-in-Life Test in a sample of 152 persons (mean age = 46 years), were similar to those found in other populations. Moderate correlations with self-transcendence and female gender; older age, and higher self-report of health status were found. Self-transcendence was strongly correlated with sense of coherence, self-esteem, hope, and variables assessing emotional well-being.

  5. Amphibians and reptiles of the state of Coahuila, Mexico, with comparison with adjoining states

    OpenAIRE

    Lemos-Espinal, Julio A.; Smith, Geoffrey R.

    2016-01-01

    Abstract We compiled a checklist of the amphibians and reptiles of the state of Coahuila, Mexico. The list comprises 133 species (24 amphibians, 109 reptiles), representing 27 families (9 amphibians, 18 reptiles) and 65 genera (16 amphibians, 49 reptiles). Coahuila has a high richness of lizards in the genus Sceloporus . Coahuila has relatively few state endemics, but has several regional endemics. Overlap in the herpetofauna of Coahuila and bordering states is fairly extensive. Of the 132 sp...

  6. Vast underestimation of Madagascar's biodiversity evidenced by an integrative amphibian inventory.

    Science.gov (United States)

    Vieites, David R; Wollenberg, Katharina C; Andreone, Franco; Köhler, Jörn; Glaw, Frank; Vences, Miguel

    2009-05-19

    Amphibians are in decline worldwide. However, their patterns of diversity, especially in the tropics, are not well understood, mainly because of incomplete information on taxonomy and distribution. We assess morphological, bioacoustic, and genetic variation of Madagascar's amphibians, one of the first near-complete taxon samplings from a biodiversity hotspot. Based on DNA sequences of 2,850 specimens sampled from over 170 localities, our analyses reveal an extreme proportion of amphibian diversity, projecting an almost 2-fold increase in species numbers from the currently described 244 species to a minimum of 373 and up to 465. This diversity is widespread geographically and across most major phylogenetic lineages except in a few previously well-studied genera, and is not restricted to morphologically cryptic clades. We classify the genealogical lineages in confirmed and unconfirmed candidate species or deeply divergent conspecific lineages based on concordance of genetic divergences with other characters. This integrative approach may be widely applicable to improve estimates of organismal diversity. Our results suggest that in Madagascar the spatial pattern of amphibian richness and endemism must be revisited, and current habitat destruction may be affecting more species than previously thought, in amphibians as well as in other animal groups. This case study suggests that worldwide tropical amphibian diversity is probably underestimated at an unprecedented level and stresses the need for integrated taxonomic surveys as a basis for prioritizing conservation efforts within biodiversity hotspots.

  7. A new case of alert about a possible menace to native fauna of amphibians in Colombia: first report of the bull frog (Lithobates catesbeianus) in the savanna of Bogota

    International Nuclear Information System (INIS)

    Mueses Cisneros, Jhon Jairo; Ballen, Gustavo

    2007-01-01

    Two specimens of bullfrog (Lithobates catesbeianus) in two different localities of Bogota are reported. Knowing the devastating effect that this species produces to the native populations of amphibians where it is introduced, we warn of the possible danger that the species of amphibians of the sabana of Bogota can suffer if no controls on the management and trade of this species are done

  8. Demonstration and Certification of Amphibian Ecological Risk Assessment Protocol

    Science.gov (United States)

    2009-04-01

    pools observed on site persist through the breeding season and long enough for the larvae to metamorphose, suitable amphibian breeding habitat exists in...frog (R. palustris): vocalizations • Fairy shrimp (Eubranchipus sp.): dip net • Isopoda: dip net • Unknown water beetle (Coleoptera): dip net...oxygen-lacking) conditions that favor the growth and regeneration of hydrophytic vegetation)) to amphibians. This test procedure uses larvae of the

  9. Climate warming and the decline of amphibians and reptiles in Europe

    DEFF Research Database (Denmark)

    Araújo, Miguel B.; Thuiller, W.; Pearson, R. G.

    2006-01-01

    deleterious than previously postulated; indeed, climate cooling would be more deleterious for the persistence of amphibian and reptile species than warming. The ability of species to cope with climate warming may, however, be offset by projected decreases in the availability of water. This should......-east are projected to gain suitable climate. This is because dry conditions in the south-west are projected to increase, approaching the levels found in North Africa, where few amphibian species are able to persist. Main conclusions The impact of increasing temperatures on amphibian and reptile species may be less...

  10. Helminth parasites of amphibians and reptiles from the Ucayali Region, Peru.

    Science.gov (United States)

    McAllister, Chris T; Bursey, Charles R; Freed, Paul S

    2010-04-01

    Twenty individual amphibians representing 9 species within 6 families and 44 individual reptiles representing 15 species within 8 families from the Ucayali Region, Peru, were examined for helminths. Seven (35%) of the amphibian species and 15 (34%) of the reptiles were found to harbor at least 1 species of helminth; 5 (25%) of the amphibians and 4 (9%) of the reptiles harbored multiple infections. A cyclophyllidean cestode and 14 taxa of nematodes within 7 families were found in the herpetofauna surveyed. Thirteen new host and 6 new geographic distribution records are documented.

  11. Body water distribution and risk of cardiovascular morbidity and mortality in a healthy population

    DEFF Research Database (Denmark)

    Knudsen, Nikoline Nygård; Kjærulff, Thora Majlund; Ward, Leigh Cordwin

    2014-01-01

    Early alterations in the cardiovascular structure and function may change normal body water distribution. The resulting fluid shifts may thus serve as an early marker for cardiovascular disease. However, studies examining this in healthy populations are absent.......Early alterations in the cardiovascular structure and function may change normal body water distribution. The resulting fluid shifts may thus serve as an early marker for cardiovascular disease. However, studies examining this in healthy populations are absent....

  12. Rainforest: Reptiles and Amphibians

    Science.gov (United States)

    Olson, Susanna

    2006-01-01

    Rainforest reptiles and amphibians are a vibrantly colored, multimedia art experience. To complete the entire project one may need to dedicate many class periods to production, yet in each aspect of the project a new and important skill, concept, or element is being taught or reinforced. This project incorporates the study of warm and cool color…

  13. Sampling methods for amphibians in streams in the Pacific Northwest.

    Science.gov (United States)

    R. Bruce Bury; Paul Stephen. Corn

    1991-01-01

    Methods describing how to sample aquatic and semiaquatic amphibians in small streams and headwater habitats in the Pacific Northwest are presented. We developed a technique that samples 10-meter stretches of selected streams, which was adequate to detect presence or absence of amphibian species and provided sample sizes statistically sufficient to compare abundance of...

  14. Fish kidney cells show higher tolerance to hyperosmolality than amphibian

    Directory of Open Access Journals (Sweden)

    Lang Gui

    2018-05-01

    Full Text Available In contrast to fish, amphibians inhabit both aquatic and terrestrial environments. To better understand osmoregulation in fish and amphibian, we have investigated the morphological changes in kidney cells to osmotic stress. To address this, kidney cell line isolated from the freshwater grass carp (CIK and Chinese giant salamander (GSK were challenged to different mediums with distinct osmotic pressures (100, 300 and 700 mOsm. Morphological alterations of the fish and amphibian cells were compared by optical and electron microscopy. Following hyposmotic treatment (100 mOsm, both CIK and GSK cells became unhealthy and show condensed chromatin, swollen mitochondria and cytoplasmic vacuole. Meanwhile, after hyperosmotic treatment (700 mOsm, shrunken CIK cells with multipolar shape, pale or lightly stained cytoplasm, condensed chromatin, vacuoles and swollen mitochondria were detected. GSK cells were seriously damaged and most were completely lysed. The results suggest that fish kidney cells show a higher degree of tolerance to hyperosmoticity by comparing to amphibians and provide novel insights on the osmoregulatory capacity and adaptability of kidney cells between the two animal groups.

  15. An unprecedented role reversal: ground beetle larvae (Coleoptera: Carabidae lure amphibians and prey upon them.

    Directory of Open Access Journals (Sweden)

    Gil Wizen

    Full Text Available Amphibians often feed on beetle larvae, including those of ground beetles (Carabidae. Preliminary reports have detailed an unusual trophic interaction in which, in contrast, larvae of the ground beetle Epomis prey upon juvenile and adult amphibians. While it is known that these larvae feed exclusively on amphibians, how the predator-prey encounter occurs to the advantage of the beetle larvae had been unknown to date. Using laboratory observations and controlled experiments, we recorded the feeding behavior of Epomis larvae, as well as the behavior of their amphibian prey. Here we reveal that larvae of two species of Epomis (E. circumscriptus and E. dejeani lure their potential predator, taking advantage of the amphibian's predation behavior. The Epomis larva combines a sit-and-wait strategy with unique movements of its antennae and mandibles to draw the attention of the amphibian to the presence of a potential prey. The intensity of this enticement increases with decreasing distance between the larva and the amphibian. When the amphibian attacks, the larva almost always manages to avoid the predator's protracted tongue, exploiting the opportunity to attach itself to the amphibian's body and initiate feeding. Our findings suggest that the trophic interaction between Epomis larvae and amphibians is one of the only natural cases of obligatory predator-prey role reversal. Moreover, this interaction involves a small insect larva that successfully lures and preys on a larger vertebrate. Such role reversal is exceptional in the animal world, extending our perspective of co-evolution in the arms race between predator and prey, and suggesting that counterattack defense behavior has evolved into predator-prey role reversal.

  16. Reproduction, embryonic development, and maternal transfer of contaminants in the amphibian Gastrophryne carolinensis.

    Science.gov (United States)

    Hopkins, William Alexander; DuRant, Sarah Elizabeth; Staub, Brandon Patrick; Rowe, Christopher Lee; Jackson, Brian Phillip

    2006-05-01

    Although many amphibian populations around the world are declining at alarming rates, the cause of most declines remains unknown. Environmental contamination is one of several factors implicated in declines and may have particularly important effects on sensitive developmental stages. Despite the severe effects of maternal transfer of contaminants on early development in other vertebrate lineages, no studies have examined the effects of maternal transfer of contaminants on reproduction or development in amphibians. We examined maternal transfer of contaminants in eastern narrow-mouth toads (Gastrophryne carolinensis) collected from a reference site and near a coal-burning power plant. Adult toads inhabiting the industrial area transferred significant quantities of selenium and strontium to their eggs, but Se concentrations were most notable (up to 100 microg/g dry mass). Compared with the reference site, hatching success was reduced by 11% in clutches from the contaminated site. In surviving larvae, the frequency of developmental abnormalities and abnormal swimming was 55-58% higher in the contaminated site relative to the reference site. Craniofacial abnormalities were nearly an order of magnitude more prevalent in hatchlings from the contaminated site. When all developmental criteria were considered collectively, offspring from the contaminated site experienced 19% lower viability. Although there was no statistical relationship between the concentration of Se or Sr transferred to eggs and any measure of offspring viability, our study demonstrates that maternal transfer may be an important route of contaminant exposure in amphibians that has been overlooked.

  17. Coincident mass extirpation of neotropical amphibians with the emergence of the infectious fungal pathogen Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Cheng, Tina L; Rovito, Sean M; Wake, David B; Vredenburg, Vance T

    2011-06-07

    Amphibians highlight the global biodiversity crisis because ∼40% of all amphibian species are currently in decline. Species have disappeared even in protected habitats (e.g., the enigmatic extinction of the golden toad, Bufo periglenes, from Costa Rica). The emergence of a fungal pathogen, Batrachochytrium dendrobatidis (Bd), has been implicated in a number of declines that have occurred in the last decade, but few studies have been able to test retroactively whether Bd emergence was linked to earlier declines and extinctions. We describe a noninvasive PCR sampling technique that detects Bd in formalin-preserved museum specimens. We detected Bd by PCR in 83-90% (n = 38) of samples that were identified as positive by histology. We examined specimens collected before, during, and after major amphibian decline events at established study sites in southern Mexico, Guatemala, and Costa Rica. A pattern of Bd emergence coincident with decline at these localities is revealed-the absence of Bd over multiple years at all localities followed by the concurrent emergence of Bd in various species at each locality during a period of population decline. The geographical and chronological emergence of Bd at these localities also indicates a southbound spread from southern Mexico in the early 1970s to western Guatemala in the 1980s/1990s and to Monteverde, Costa Rica by 1987. We find evidence of a historical "Bd epidemic wave" that began in Mexico and subsequently spread to Central America. We describe a technique that can be used to screen museum specimens from other amphibian decline sites around the world.

  18. Intermediate pond sizes contain the highest density, richness, and diversity of pond-breeding amphibians.

    Directory of Open Access Journals (Sweden)

    Raymond D Semlitsch

    Full Text Available We present data on amphibian density, species richness, and diversity from a 7140-ha area consisting of 200 ponds in the Midwestern U.S. that represents most of the possible lentic aquatic breeding habitats common in this region. Our study includes all possible breeding sites with natural and anthropogenic disturbance processes that can be missing from studies where sampling intensity is low, sample area is small, or partial disturbance gradients are sampled. We tested whether pond area was a significant predictor of density, species richness, and diversity of amphibians and if values peaked at intermediate pond areas. We found that in all cases a quadratic model fit our data significantly better than a linear model. Because small ponds have a high probability of pond drying and large ponds have a high probability of fish colonization and accumulation of invertebrate predators, drying and predation may be two mechanisms driving the peak of density and diversity towards intermediate values of pond size. We also found that not all intermediate sized ponds produced many larvae; in fact, some had low amphibian density, richness, and diversity. Further analyses of the subset of ponds represented in the peak of the area distribution showed that fish, hydroperiod, invertebrate density, and canopy are additional factors that drive density, richness and diversity of ponds up or down, when extremely small or large ponds are eliminated. Our results indicate that fishless ponds at intermediate sizes are more diverse, produce more larvae, and have greater potential to recruit juveniles into adult populations of most species sampled. Further, hylid and chorus frogs are found predictably more often in ephemeral ponds whereas bullfrogs, green frogs, and cricket frogs are found most often in permanent ponds with fish. Our data increase understanding of what factors structure and maintain amphibian diversity across large landscapes.

  19. Understanding of the impact of chemicals on amphibians: a meta-analytic review.

    Science.gov (United States)

    Egea-Serrano, Andrés; Relyea, Rick A; Tejedo, Miguel; Torralva, Mar

    2012-07-01

    Many studies have assessed the impact of different pollutants on amphibians across a variety of experimental venues (laboratory, mesocosm, and enclosure conditions). Past reviews, using vote-counting methods, have described pollution as one of the major threats faced by amphibians. However, vote-counting methods lack strong statistical power, do not permit one to determine the magnitudes of effects, and do not compare responses among predefined groups. To address these challenges, we conducted a meta-analysis of experimental studies that measured the effects of different chemical pollutants (nitrogenous and phosphorous compounds, pesticides, road deicers, heavy metals, and other wastewater contaminants) at environmentally relevant concentrations on amphibian survival, mass, time to hatching, time to metamorphosis, and frequency of abnormalities. The overall effect size of pollutant exposure was a medium decrease in amphibian survival and mass and a large increase in abnormality frequency. This translates to a 14.3% decrease in survival, a 7.5% decrease in mass, and a 535% increase in abnormality frequency across all studies. In contrast, we found no overall effect of pollutants on time to hatching and time to metamorphosis. We also found that effect sizes differed among experimental venues and among types of pollutants, but we only detected weak differences among amphibian families. These results suggest that variation in sensitivity to contaminants is generally independent of phylogeny. Some publication bias (i.e., selective reporting) was detected, but only for mass and the interaction effect size among stressors. We conclude that the overall impact of pollution on amphibians is moderately to largely negative. This implies that pollutants at environmentally relevant concentrations pose an important threat to amphibians and may play a role in their present global decline.

  20. Development of a mobile application for amphibian species recognition

    International Nuclear Information System (INIS)

    Parveen, B; Chew T H; Shamsir, M S; Ahmad, N

    2014-01-01

    The smartphones mobility and its pervasiveness are beginning to transform practices in biodiversity conservation. The integrated functionalities of a smartphone have created for the public and biodiversity specialists means to identify, gather and record biodiversity data while simultaneously creating knowledge portability in the digital forms of mobile guides. Smartphones enable beginners to recreate the delight of species identification usually reserved for specialist with years of experience. Currently, the advent of Android platform has enabled stakeholders in biodiversity to harness the ubiquity of this platform and create various types of mobile application or ''apps'' for use in biodiversity research and conservation. However, there is an apparent lack of application devoted to the identification in herpetofauna or amphibian science. Amphibians are a large class of animals with many different species still unidentified under this category. Here we describe the development of an app called Amphibian Recognition Android Application (ARAA) to identify frog amphibian species as well as an accompanying field guide. The app has the amphibian taxonomic key which assists the users in easy and rapid species identification, thus facilitating the process of identification and recording of species occurrences in conservation work. We will also present an overview of the application work flow and how it is designed to meet the needs a conservationist. As this application is still in its beta phase, further research is required to improve the application to include tools such automatic geolocation and geotagging, participative sensing via crowdsourcing and automated identification via image capture. We believe that the introduction of this app will create an impetus to the awareness of nature via species identification

  1. Development of a mobile application for amphibian species recognition

    Science.gov (United States)

    Parveen, B.; H, Chew T.; Shamsir, M. S.; Ahmad, N.

    2014-02-01

    The smartphones mobility and its pervasiveness are beginning to transform practices in biodiversity conservation. The integrated functionalities of a smartphone have created for the public and biodiversity specialists means to identify, gather and record biodiversity data while simultaneously creating knowledge portability in the digital forms of mobile guides. Smartphones enable beginners to recreate the delight of species identification usually reserved for specialist with years of experience. Currently, the advent of Android platform has enabled stakeholders in biodiversity to harness the ubiquity of this platform and create various types of mobile application or "apps" for use in biodiversity research and conservation. However, there is an apparent lack of application devoted to the identification in herpetofauna or amphibian science. Amphibians are a large class of animals with many different species still unidentified under this category. Here we describe the development of an app called Amphibian Recognition Android Application (ARAA) to identify frog amphibian species as well as an accompanying field guide. The app has the amphibian taxonomic key which assists the users in easy and rapid species identification, thus facilitating the process of identification and recording of species occurrences in conservation work. We will also present an overview of the application work flow and how it is designed to meet the needs a conservationist. As this application is still in its beta phase, further research is required to improve the application to include tools such automatic geolocation and geotagging, participative sensing via crowdsourcing and automated identification via image capture. We believe that the introduction of this app will create an impetus to the awareness of nature via species identification.

  2. A test of the substitution-habitat hypothesis in amphibians.

    Science.gov (United States)

    Martínez-Abraín, Alejandro; Galán, Pedro

    2017-12-08

    Most examples that support the substitution-habitat hypothesis (human-made habitats act as substitutes of original habitat) deal with birds and mammals. We tested this hypothesis in 14 amphibians by using percentage occupancy as a proxy of habitat quality (i.e., higher occupancy percentages indicate higher quality). We classified water body types as original habitat (no or little human influence) depending on anatomical, behavioral, or physiological adaptations of each amphibian species. Ten species had relatively high probabilities (0.16-0.28) of occurrence in original habitat, moderate probability of occurrence in substitution habitats (0.11-0.14), and low probability of occurrence in refuge habitats (0.05-0.08). Thus, the substitution-habitat hypothesis only partially applies to amphibians because the low occupancy of refuges could be due to the negligible human persecution of this group (indicating good conservation status). However, low occupancy of refuges could also be due to low tolerance of refuge conditions, which could have led to selective extinction or colonization problems due to poor dispersal capabilities. That original habitats had the highest probabilities of occupancy suggests amphibians have a good conservation status in the region. They also appeared highly adaptable to anthropogenic substitution habitats. © 2017 Society for Conservation Biology.

  3. Risk assessment considerations for plant protection products and terrestrial life-stages of amphibians.

    Science.gov (United States)

    Weltje, Lennart; Ufer, Andreas; Hamer, Mick; Sowig, Peter; Demmig, Sandra; Dechet, Friedrich

    2018-04-28

    Some amphibians occur in agricultural landscapes during certain periods of their life cycle and consequently might be exposed to plant protection products (PPPs). While the sensitivity of aquatic life-stages is considered to be covered by the standard assessment for aquatic organisms (especially fish), the situation is less clear for terrestrial amphibian life-stages. In this paper, considerations are presented on how a risk assessment for PPPs and terrestrial life-stages of amphibians could be conducted. It discusses available information concerning the toxicity of PPPs to terrestrial amphibians, and their potential exposure to PPPs in consideration of aspects of amphibian biology. The emphasis is on avoiding additional vertebrate testing as much as possible by using exposure-driven approaches and by making use of existing vertebrate toxicity data, where appropriate. Options for toxicity testing and risk assessment are presented in a flowchart as a tiered approach, progressing from a non-testing approach, to simple worst-case laboratory testing, to extended laboratory testing, to semi-field enclosure tests and ultimately to full-scale field testing and monitoring. Suggestions are made for triggers to progress to higher tiers. Also, mitigation options to reduce the potential for exposure of terrestrial life-stages of amphibians to PPPs, if a risk were identified, are discussed. Finally, remaining uncertainties and research needs are considered by proposing a way forward (road map) for generating additional information to inform terrestrial amphibian risk assessment. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Mitogenomic perspectives on the origin and phylogeny of living amphibians.

    Science.gov (United States)

    Zhang, Peng; Zhou, Hui; Chen, Yue-Qin; Liu, Yi-Fei; Qu, Liang-Hu

    2005-06-01

    Establishing the relationships among modern amphibians (lissamphibians) and their ancient relatives is necessary for our understanding of early tetrapod evolution. However, the phylogeny is still intractable because of the highly specialized anatomy and poor fossil record of lissamphibians. Paleobiologists are still not sure whether lissamphibians are monophyletic or polyphyletic, and which ancient group (temnospondyls or lepospondyls) is most closely related to them. In an attempt to address these problems, eight mitochondrial genomes of living amphibians were determined and compared with previously published amphibian sequences. A comprehensive molecular phylogenetic analysis of nucleotide sequences yields a highly resolved tree congruent with the traditional hypotheses (Batrachia). By using a molecular clock-independent approach for inferring dating information from molecular phylogenies, we present here the first molecular timescale for lissamphibian evolution, which suggests that lissamphibians first emerged about 330 million years ago. By observing the fit between molecular and fossil times, we suggest that the temnospondyl-origin hypothesis for lissamphibians is more credible than other hypotheses. Moreover, under this timescale, the potential geographic origins of the main living amphibian groups are discussed: (i) advanced frogs (neobatrachians) may possess an Africa-India origin; (ii) salamanders may have originated in east Asia; (iii) the tropic forest of the Triassic Pangaea may be the place of origin for the ancient caecilians. An accurate phylogeny with divergence times can be also helpful to direct the search for "missing" fossils, and can benefit comparative studies of amphibian evolution.

  5. Cross-tolerance in amphibians: wood frog mortality when exposed to three insecticides with a common mode of action.

    Science.gov (United States)

    Hua, Jessica; Cothran, Rickey; Stoler, Aaron; Relyea, Rick

    2013-04-01

    Insecticide tolerance and cross-tolerance in nontarget organisms is often overlooked despite its potential to buffer natural systems from anthropogenic influence. We exposed wood frog tadpoles from 15 populations to three acetylcholine esterase-inhibiting insecticides and found widespread variation in insecticide tolerance and evidence for cross-tolerance to these insecticides. Our results demonstrate that amphibian populations with tolerance to one pesticide may be tolerant to many other pesticides. Copyright © 2013 SETAC.

  6. Relationship Between Landscape Character, UV Exposure, and Amphibian Decline

    Science.gov (United States)

    O'Reilly, C. M.; Brooks, P. D.; Corn, P. S.; Muths, E.; Campbell, D. H.; Diamond, S.; Tonnessen, K.

    2001-12-01

    Widespread reports of amphibian declines have been considered a warning of large-scale environmental degradation, yet the reasons for these declines remain unclear. This study suggests that exposure to ultraviolet radiation may act as an environmental stressor that affects population breeding success or susceptibility to disease. Ultraviolet radiation is attenuated by dissolved and particulate compounds in water, which may be of either terrestrial or aquatic origin. UV attenuation by dissolved organic carbon (DOC) is primarily due to compounds in the fulvic acid fraction, which originate in soil environments. These terrestrially-derived fulvic acids are transported to during hydrologic flushing events such as snowmelt and episodic precipitation and play an important role in controlling UV exposure in surface waters. As part of a previously published project, amphibian surveys were conducted at seventeen sites in Rocky Mountain National Park both during, and subsequent to, a three-year drought (1988 - 1990). During this period, ten sites lost one amphibian species, while only one site gained a previously unreported species. One possible explanation for these localized species losses is increased exposure to UV radiation, mediated by reduced terrestrial DOC inputs during dry periods. Several subsequent years of water chemistry data showed that the sites with documented species losses were characterized by a range of DOC concentrations, but tended to have a greater proportion of terrestrial DOC than sites that did not undergo species loss. This suggests that terrestrial inputs exert a strong control on DOC concentrations that may influence species success. We used physical environmental factors to develop a classification scheme for these sites. There are many physical factors that can influence terrestrial DOC inputs, including landscape position, geomorphology, soil type, and watershed vegetation. In addition, we considered the possible effects on internal aquatic

  7. Reptiles as potential vectors and hosts of the amphibian pathogen Batrachochytrium dendrobatidis in Panama.

    Science.gov (United States)

    Kilburn, Vanessa L; Ibáñez, Roberto; Green, David M

    2011-12-06

    Chytridiomycosis, the disease caused by Batrachochytrium dendrobatidis, is considered to be a disease exclusively of amphibians. However, B. dendrobatidis may also be capable of persisting in the environment, and non-amphibian vectors or hosts may contribute to disease transmission. Reptiles living in close proximity to amphibians and sharing similar ecological traits could serve as vectors or reservoir hosts for B. dendrobatidis, harbouring the organism on their skin without succumbing to disease. We surveyed for the presence of B. dendrobatidis DNA among 211 lizards and 8 snakes at 8 sites at varying elevations in Panama where the syntopic amphibians were at pre-epizootic, epizootic or post-epizootic stages of chytridiomycosis. Detection of B. dendrobatidis DNA was done using qPCR analysis. Evidence of the amphibian pathogen was present at varying intensities in 29 of 79 examined Anolis humilis lizards (32%) and 9 of 101 A. lionotus lizards (9%), and in one individual each of the snakes Pliocercus euryzonus, Imantodes cenchoa, and Nothopsis rugosus. In general, B. dendrobatidis DNA prevalence among reptiles was positively correlated with the infection prevalence among co-occurring anuran amphibians at any particular site (r = 0.88, p = 0.004). These reptiles, therefore, may likely be vectors or reservoir hosts for B. dendrobatidis and could serve as disease transmission agents. Although there is no evidence of B. dendrobatidis disease-induced declines in reptiles, cases of coincidence of reptile and amphibian declines suggest this potentiality. Our study is the first to provide evidence of non-amphibian carriers for B. dendrobatidis in a natural Neotropical environment.

  8. Vegetation patterns and abundances of amphibians and small mammals along small streams in a northwestern California watershed

    Science.gov (United States)

    Jeffrey R. Waters; Cynthia J. Zabel; Kevin S. McKelvey; Hartwell H. Welsh

    2001-01-01

    Our goal was to describe and evaluate patterns of association between stream size and abundances of amphibians and small mammals in a northwestern California watershed. We sampled populations at 42 stream sites and eight upland sites within a 100- watershed in 1995 and 1996. Stream reaches sampled ranged from poorly defined channels that rarely flowed to 10-m-wide...

  9. Unexpected metabolic disorders induced by endocrine disruptors in Xenopus tropicalis provide new lead for understanding amphibian decline.

    Science.gov (United States)

    Regnault, Christophe; Usal, Marie; Veyrenc, Sylvie; Couturier, Karine; Batandier, Cécile; Bulteau, Anne-Laure; Lejon, David; Sapin, Alexandre; Combourieu, Bruno; Chetiveaux, Maud; Le May, Cédric; Lafond, Thomas; Raveton, Muriel; Reynaud, Stéphane

    2018-05-08

    Despite numerous studies suggesting that amphibians are highly sensitive to endocrine disruptors (EDs), both their role in the decline of populations and the underlying mechanisms remain unclear. This study showed that frogs exposed throughout their life cycle to ED concentrations low enough to be considered safe for drinking water, developed a prediabetes phenotype and, more commonly, a metabolic syndrome. Female Xenopus tropicalis exposed from tadpole stage to benzo( a )pyrene or triclosan at concentrations of 50 ng⋅L -1 displayed glucose intolerance syndrome, liver steatosis, liver mitochondrial dysfunction, liver transcriptomic signature, and pancreatic insulin hypersecretion, all typical of a prediabetes state. This metabolic syndrome led to progeny whose metamorphosis was delayed and occurred while the individuals were both smaller and lighter, all factors that have been linked to reduced adult recruitment and likelihood of reproduction. We found that F 1 animals did indeed have reduced reproductive success, demonstrating a lower fitness in ED-exposed Xenopus Moreover, after 1 year of depuration, Xenopus that had been exposed to benzo( a )pyrene still displayed hepatic disorders and a marked insulin secretory defect resulting in glucose intolerance. Our results demonstrate that amphibians are highly sensitive to EDs at concentrations well below the thresholds reported to induce stress in other vertebrates. This study introduces EDs as a possible key contributing factor to amphibian population decline through metabolism disruption. Overall, our results show that EDs cause metabolic disorders, which is in agreement with epidemiological studies suggesting that environmental EDs might be one of the principal causes of metabolic disease in humans.

  10. Acute oral toxicity of chemicals in terrestrial life stages of amphibians: Comparisons to birds and mammals.

    Science.gov (United States)

    Crane, Mark; Finnegan, Meaghean; Weltje, Lennart; Kosmala-Grzechnik, Sylwia; Gross, Melanie; Wheeler, James R

    2016-10-01

    Amphibians are currently the most threatened and rapidly declining group of vertebrates and this has raised concerns about their potential sensitivity and exposure to plant protection products and other chemicals. Current environmental risk assessment procedures rely on surrogate species (e.g. fish and birds) to cover the risk to aquatic and terrestrial life stages of amphibians, respectively. Whilst a recent meta-analysis has shown that in most cases amphibian aquatic life stages are less sensitive to chemicals than fish, little research has been conducted on the comparative sensitivity of terrestrial amphibian life stages. Therefore, in this paper we address the questions "What is the relative sensitivity of terrestrial amphibian life stages to acute chemical oral exposure when compared with mammals and birds?" and "Are there correlations between oral toxicity data for amphibians and data for mammals or birds?" Identifying a relationship between these data may help to avoid additional vertebrate testing. Acute oral amphibian toxicity data collected from the scientific literature and ecotoxicological databases were compared with toxicity data for mammals and birds. Toxicity data for terrestrial amphibian life stages are generally sparse, as noted in previous reviews. Single-dose oral toxicity data for terrestrial amphibian life stages were available for 26 chemicals and these were positively correlated with LD50 values for mammals, while no correlation was found for birds. Further, the data suggest that oral toxicity to terrestrial amphibian life stages is similar to or lower than that for mammals and birds, with a few exceptions. Thus, mammals or birds are considered adequate toxicity surrogates for use in the assessment of the oral exposure route in amphibians. However, there is a need for further data on a wider range of chemicals to explore the wider applicability of the current analyses and recommendations. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Assessing the links among environmental contaminants, endocrinology, and parasites to understand amphibian declines in montane regions of Costa Rica.

    Science.gov (United States)

    Leary, Christopher J; Ralicki, Hannah F; Laurencio, David; Crocker-Buta, Sarah; Malone, John H

    2018-01-01

    Amphibians inhabiting montane riparian zones in the Neotropics are particularly vulnerable to decline, but the reasons are poorly understood. Because environmental contaminants, endocrine disruption, and pathogens often figure prominently in amphibian declines it is imperative that we understand how these factors are potentially interrelated to affect montane populations. One possibility is that increased precipitation associated with global warming promotes the deposition of contaminants in montane regions. Increased exposure to contaminants, in turn, potentially elicits chronic elevations in circulating stress hormones that could contribute to montane population declines by compromising resistance to pathogens and/or production of sex steroids regulating reproduction. Here, we test this hypothesis by examining contaminant levels, stress and sex steroid levels, and nematode abundances in male drab treefrogs, Smilisca sordida, from lowland and montane populations in Costa Rica. We found no evidence that montane populations were more likely to possess contaminants (i.e., organochlorine, organophosphate and carbamate pesticides or benzidine and chlorophenoxy herbicides) than lowland populations. We also found no evidence of elevational differences in circulating levels of the stress hormone corticosterone, estradiol or progesterone. However, montane populations possessed lower androgen levels, hosted more nematode species, and had higher nematode abundances than lowland populations. Although these results suggested that nematodes contributed to lower androgens in montane populations, we were unable to detect a significant inverse relationship between nematode abundance and androgen level. Our results suggest that montane populations of this species are not at greater risk of exposure to contaminants or chronic stress, but implicate nematodes and compromised sex steroid levels as potential threats to montane populations.

  12. Assessing the links among environmental contaminants, endocrinology, and parasites to understand amphibian declines in montane regions of Costa Rica.

    Directory of Open Access Journals (Sweden)

    Christopher J Leary

    Full Text Available Amphibians inhabiting montane riparian zones in the Neotropics are particularly vulnerable to decline, but the reasons are poorly understood. Because environmental contaminants, endocrine disruption, and pathogens often figure prominently in amphibian declines it is imperative that we understand how these factors are potentially interrelated to affect montane populations. One possibility is that increased precipitation associated with global warming promotes the deposition of contaminants in montane regions. Increased exposure to contaminants, in turn, potentially elicits chronic elevations in circulating stress hormones that could contribute to montane population declines by compromising resistance to pathogens and/or production of sex steroids regulating reproduction. Here, we test this hypothesis by examining contaminant levels, stress and sex steroid levels, and nematode abundances in male drab treefrogs, Smilisca sordida, from lowland and montane populations in Costa Rica. We found no evidence that montane populations were more likely to possess contaminants (i.e., organochlorine, organophosphate and carbamate pesticides or benzidine and chlorophenoxy herbicides than lowland populations. We also found no evidence of elevational differences in circulating levels of the stress hormone corticosterone, estradiol or progesterone. However, montane populations possessed lower androgen levels, hosted more nematode species, and had higher nematode abundances than lowland populations. Although these results suggested that nematodes contributed to lower androgens in montane populations, we were unable to detect a significant inverse relationship between nematode abundance and androgen level. Our results suggest that montane populations of this species are not at greater risk of exposure to contaminants or chronic stress, but implicate nematodes and compromised sex steroid levels as potential threats to montane populations.

  13. Global patterns of evolutionary distinct and globally endangered amphibians and mammals.

    Science.gov (United States)

    Safi, Kamran; Armour-Marshall, Katrina; Baillie, Jonathan E M; Isaac, Nick J B

    2013-01-01

    Conservation of phylogenetic diversity allows maximising evolutionary information preserved within fauna and flora. The "EDGE of Existence" programme is the first institutional conservation initiative that prioritises species based on phylogenetic information. Species are ranked in two ways: one according to their evolutionary distinctiveness (ED) and second, by including IUCN extinction status, their evolutionary distinctiveness and global endangerment (EDGE). Here, we describe the global patterns in the spatial distribution of priority ED and EDGE species, in order to identify conservation areas for mammalian and amphibian communities. In addition, we investigate whether environmental conditions can predict the observed spatial pattern in ED and EDGE globally. Priority zones with high concentrations of ED and EDGE scores were defined using two different methods. The overlap between mammal and amphibian zones was very small, reflecting the different phylo-biogeographic histories. Mammal ED zones were predominantly found on the African continent and the neotropical forests, whereas in amphibians, ED zones were concentrated in North America. Mammal EDGE zones were mainly in South-East Asia, southern Africa and Madagascar; for amphibians they were in central and south America. The spatial pattern of ED and EDGE was poorly described by a suite of environmental variables. Mapping the spatial distribution of ED and EDGE provides an important step towards identifying priority areas for the conservation of mammalian and amphibian phylogenetic diversity in the EDGE of existence programme.

  14. The potential influence of environmental pollution on amphibian development and decline

    Energy Technology Data Exchange (ETDEWEB)

    Jung, R.E.

    1996-12-31

    Globally, amphibians are reportedly declining. Environmental pollution has been hypothesized to be associated with declines. Because of their aquatic development and permeable eggs, skin and gills, amphibians, like fishes, may be particularly susceptible to poor water quality or waterborne pollutants. This dissertation addresses effects of global pollutants such as pesticides, acid rain and associated metal toxicity, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and polychlorinated biphenyls (PCBs) on the development, behavior, and physiology of amphibian early life stages. This report contains only chapter six and conclusions. Chapter 6 reports on a field experiment in which green frogs from two clutches were exposed from egg to 107 days of age to water and sediments in enclosures along a PCB and metal contamination gradient in the Fox River and wetlands near Green Bay, Wisconsin. Green frogs showed lower hatching success and survival at sites with higher contaminant levels compared to cleaner wetland sites along Green Bay. Hatching success in the green frog was most significantly negatively correlated with sediment PCB levels. It can be concluded that environmental pollution and toxicants in aquatic environments can cause problems for amphibian early development. Sometimes the effects are subtle, and sometimes they are dramatic. In general, amphibian early life stages seem particularly sensitive to environmentally-realistic levels of low pH and metals, but appear more tolerant of TCDD and PCBs.

  15. Agrochemicals increase trematode infections in a declining amphibian species.

    Science.gov (United States)

    Rohr, Jason R; Schotthoefer, Anna M; Raffel, Thomas R; Carrick, Hunter J; Halstead, Neal; Hoverman, Jason T; Johnson, Catherine M; Johnson, Lucinda B; Lieske, Camilla; Piwoni, Marvin D; Schoff, Patrick K; Beasley, Val R

    2008-10-30

    Global amphibian declines have often been attributed to disease, but ignorance of the relative importance and mode of action of potential drivers of infection has made it difficult to develop effective remediation. In a field study, here we show that the widely used herbicide, atrazine, was the best predictor (out of more than 240 plausible candidates) of the abundance of larval trematodes (parasitic flatworms) in the declining northern leopard frog Rana pipiens. The effects of atrazine were consistent across trematode taxa. The combination of atrazine and phosphate--principal agrochemicals in global corn and sorghum production--accounted for 74% of the variation in the abundance of these often debilitating larval trematodes (atrazine alone accounted for 51%). Analysis of field data supported a causal mechanism whereby both agrochemicals increase exposure and susceptibility to larval trematodes by augmenting snail intermediate hosts and suppressing amphibian immunity. A mesocosm experiment demonstrated that, relative to control tanks, atrazine tanks had immunosuppressed tadpoles, had significantly more attached algae and snails, and had tadpoles with elevated trematode loads, further supporting a causal relationship between atrazine and elevated trematode infections in amphibians. These results raise concerns about the role of atrazine and phosphate in amphibian declines, and illustrate the value of quantifying the relative importance of several possible drivers of disease risk while determining the mechanisms by which they facilitate disease emergence.

  16. Occurrence of the amphibian pathogen Batrachochytrium dendrobatidis in the Pacific Northwest.

    Science.gov (United States)

    C.A. Pearl; E.L. Bull; D.E. Green; J. Bowerman; M.J. Adams; A. Hyatt; W.H. Wente

    2007-01-01

    Chytridiomycosis (infection by the fungus Batrachochytrium dendrobatidis) is an emerging pathogen of amphibians that is associated with declines in at least four continents. We report results of disease screens from 271 field-sampled amphibians from Oregon and Washington. Chytridiomycosis was detected on 5 of 7 species and from 31 percent of all...

  17. Evaluating Amphibian Declines with Site Revisits and Occupancy Models: Status of Montane Anurans in the Pacific Northwest USA

    Directory of Open Access Journals (Sweden)

    Brome McCreary

    2009-12-01

    Full Text Available Amphibian declines have been reported in mountainous areas around the western USA. Few data quantify the extent of population losses in the Pacific Northwest, a region in which amphibian declines have received much attention. From 2001–2004, we resurveyed historical breeding sites of two species of conservation concern, the Western Toad (Bufo [=Anaxyrus] boreas and Cascades Frog (Rana cascadae. We detected B. boreas breeding at 75.9% and R. cascadae breeding at 66.6% of historical sites. When we analyzed the data using occupancy models that accounted for detection probability, we estimated the current use of historically occupied sites in our study area was 84.9% (SE = 4.9 for B. boreas and 72.4% (SE = 6.6 for R. cascadae. Our ability to detect B. boreas at sites where they were present was lower in the first year of surveys (a low snowpack year and higher at sites with introduced fish. Our ability to detect R. cascadae was lower at sites with fish. The probability that B. boreas still uses a historical site for breeding was related to the easting of the site (+ and the age of record (-. None of the variables we analyzed was strongly related to R. cascadae occupancy. Both species had increased odds of occupancy with higher latitude, but model support for this variable was modest. Our analysis suggests that while local losses are possible, these two amphibians have not experienced recent, broad population losses in the Oregon Cascades. Historical site revisitation studies such as ours cannot distinguish between population losses and site switching, and do not account for colonization of new habitats, so our analysis may overestimate declines in occupancy within our study area.

  18. Amphibians and reptiles of the state of Coahuila, Mexico, with comparison with adjoining states.

    Science.gov (United States)

    Lemos-Espinal, Julio A; Smith, Geoffrey R

    2016-01-01

    We compiled a checklist of the amphibians and reptiles of the state of Coahuila, Mexico. The list comprises 133 species (24 amphibians, 109 reptiles), representing 27 families (9 amphibians, 18 reptiles) and 65 genera (16 amphibians, 49 reptiles). Coahuila has a high richness of lizards in the genus Sceloporus. Coahuila has relatively few state endemics, but has several regional endemics. Overlap in the herpetofauna of Coahuila and bordering states is fairly extensive. Of the 132 species of native amphibians and reptiles, eight are listed as Vulnerable, six as Near Threatened, and six as Endangered in the IUCN Red List. In the SEMARNAT listing, 19 species are Subject to Special Protection, 26 are Threatened, and three are in Danger of Extinction. Coahuila is home to several species of conservation concern, especially lizards and turtles. Coahuila is an important state for the conservation of the native regional fauna.

  19. Benefits of regular aerobic exercise for executive functioning in healthy populations.

    Science.gov (United States)

    Guiney, Hayley; Machado, Liana

    2013-02-01

    Research suggests that regular aerobic exercise has the potential to improve executive functioning, even in healthy populations. The purpose of this review is to elucidate which components of executive functioning benefit from such exercise in healthy populations. In light of the developmental time course of executive functions, we consider separately children, young adults, and older adults. Data to date from studies of aging provide strong evidence of exercise-linked benefits related to task switching, selective attention, inhibition of prepotent responses, and working memory capacity; furthermore, cross-sectional fitness data suggest that working memory updating could potentially benefit as well. In young adults, working memory updating is the main executive function shown to benefit from regular exercise, but cross-sectional data further suggest that task-switching and post error performance may also benefit. In children, working memory capacity has been shown to benefit, and cross-sectional data suggest potential benefits for selective attention and inhibitory control. Although more research investigating exercise-related benefits for specific components of executive functioning is clearly needed in young adults and children, when considered across the age groups, ample evidence indicates that regular engagement in aerobic exercise can provide a simple means for healthy people to optimize a range of executive functions.

  20. Optimizing protection efforts for amphibian conservation in Mediterranean landscapes

    Science.gov (United States)

    García-Muñoz, Enrique; Ceacero, Francisco; Carretero, Miguel A.; Pedrajas-Pulido, Luis; Parra, Gema; Guerrero, Francisco

    2013-05-01

    Amphibians epitomize the modern biodiversity crisis, and attract great attention from the scientific community since a complex puzzle of factors has influence on their disappearance. However, these factors are multiple and spatially variable, and declining in each locality is due to a particular combination of causes. This study shows a suitable statistical procedure to determine threats to amphibian species in medium size administrative areas. For our study case, ten biological and ecological variables feasible to affect the survival of 15 amphibian species were categorized and reduced through Principal Component Analysis. The principal components extracted were related to ecological plasticity, reproductive potential, and specificity of breeding habitats. Finally, the factor scores of species were joined in a presence-absence matrix that gives us information to identify where and why conservation management are requires. In summary, this methodology provides the necessary information to maximize benefits of conservation measures in small areas by identifying which ecological factors need management efforts and where should we focus them on.

  1. Responses of Mammalian Insectivores, Amphibians, and Reptiles to Broad-Scale Manipulation of Coarse Woody Debris

    Energy Technology Data Exchange (ETDEWEB)

    McCay, T.S.; Forschler, B.T.; Komoroski, M.J.; Ford, W.M.

    2002-03-10

    Sampled shrews at 9.3 ha plots from logs manually removed and control plots in loblolly pine forests of the Southeastern Coastal Plain. Capture rates of Cryptotis parva were lower at plots from which deadwood was removed whereas capture rates of Blarina cavolinensis and Sorex longirostris did not differ between control and removal plots. Cryptotis may have been most sensitive to removal plots due to low population density, hence poor ability to move into areas of low reproduction. (Second Abstract, p. 37)Presentation of evidence that juvenile amphibians including Ambystomatid salamanders may disperse hundreds of meter from their natal wetlands within the weeks to months following metamorphosis. Data indicates Ambystoma trigrinum metamorphs can take at least six months to disperse and en route use non-polar lipid reserves garnished as larvae. Report suggests a land management regime that allows for both juvenile amphibian dispersal and also the consumptive use of the surrounding landscape.

  2. Amphibians and reptiles of the Calakmul Biosphere Reserve, México, with new records

    OpenAIRE

    Colston, Timothy; Barão-Nóbrega, José António; Manders, Ryan; Lett, Alice; Wilmott, Jamie; Cameron, Gavin; Hunter, Sidony; Radage, Adam; Littlefair, Etienne; Williams, Robert; Lopez Cen, Antonio; Slater, Kathy

    2015-01-01

    We provide a list of amphibians and reptiles of the Calakmul Biosphere Reserve in the southern half of the Mexican Yucatan, in the state of Campeche. The study area was sampled through opportunistic, transect and pitfall trap surveys conducted for three successive years. These surveys resulted in a total of 2,359 amphibian and reptile encounters, belonging to 20 amphibian and 69 reptile species from 24 total families. We present herein the records for one snake, one chelonian and two salamand...

  3. The Effects of Ammonium Perchlorate on Reproduction and Development of Amphibians

    Science.gov (United States)

    2008-01-01

    Mitigating Ammonium Perchlorate (AP) Exposure........................................................................18 Table 5-1. Funding History and...amphibian species were reared on perchlorate-laden food (e.g., hydroponically grown lettuce ) and their growth and development monitored. Thyroid...of Perchlorate Derived from Food Sources on Amphibian Development 8 Table 3.1 (Continued) 3.1 Initiate Lettuce Growth 3.2 Tests with Native

  4. Pesticide Mixtures, Endocrine Disruption, and Amphibian Declines: Are We Underestimating the Impact?

    Science.gov (United States)

    Hayes, Tyrone B.; Case, Paola; Chui, Sarah; Chung, Duc; Haeffele, Cathryn; Haston, Kelly; Lee, Melissa; Mai, Vien Phoung; Marjuoa, Youssra; Parker, John; Tsui, Mable

    2006-01-01

    Amphibian populations are declining globally at an alarming rate. Pesticides are among a number of proposed causes for these declines. Although a sizable database examining effects of pesticides on amphibians exists, the vast majority of these studies focus on toxicological effects (lethality, external malformations, etc.) at relatively high doses (parts per million). Very few studies focus on effects such as endocrine disruption at low concentrations. Further, most studies examine exposures to single chemicals only. The present study examined nine pesticides (four herbicides, two fungicides, and three insecticides) used on cornfields in the midwestern United States. Effects of each pesticide alone (0.1 ppb) or in combination were examined. In addition, we also examined atrazine and S-metolachlor combined (0.1 or 10 ppb each) and the commercial formulation Bicep II Magnum, which contains both of these herbicides. These two pesticides were examined in combination because they are persistent throughout the year in the wild. We examined larval growth and development, sex differentiation, and immune function in leopard frogs (Rana pipiens). In a follow-up study, we also examined the effects of the nine-compound mixture on plasma corticosterone levels in male African clawed frogs (Xenopus laevis). Although some of the pesticides individually inhibited larval growth and development, the pesticide mixtures had much greater effects. Larval growth and development were retarded, but most significantly, pesticide mixtures negated or reversed the typically positive correlation between time to metamorphosis and size at metamorphosis observed in controls: exposed larvae that took longer to metamorphose were smaller than their counterparts that metamorphosed earlier. The nine-pesticide mixture also induced damage to the thymus, resulting in immunosuppression and contraction of flavobacterial meningitis. The study in X. laevis revealed that these adverse effects may be due to an

  5. Arginine Vasotocin, the Social Neuropeptide of Amphibians and Reptiles.

    Science.gov (United States)

    Wilczynski, Walter; Quispe, Maricel; Muñoz, Matías I; Penna, Mario

    2017-01-01

    Arginine vasotocin (AVT) is the non-mammalian homolog of arginine vasopressin (AVP) and, like vasopressin, serves as an important modulator of social behavior in addition to its peripheral functions related to osmoregulation, reproductive physiology, and stress hormone release. In amphibians and reptiles, the neuroanatomical organization of brain AVT cells and fibers broadly resembles that seen in mammals and other taxa. Both parvocellular and magnocellular AVT-containing neurons are present in multiple populations located mainly in the basal forebrain from the accumbens-amygdala area to the preoptic area and hypothalamus, from which originate widespread fiber connections spanning the brain with a particularly heavy innervation of areas associated with social behavior and decision-making. As for mammalian AVP, AVT is present in greater amounts in males in many brain areas, and its presence varies seasonally, with hormonal state, and in males with differing social status. AVT's social influence is also conserved across herpetological taxa, with significant effects on social signaling and aggression, and, based on the very small number of studies investigating more complex social behaviors in amphibians and reptiles, AVT may also modulate parental care and social bonding when it is present in these vertebrates. Within this conserved pattern, however, both AVT anatomy and social behavior effects vary significantly across species. Accounting for this diversity represents a challenge to understanding the mechanisms by which AVT exerts its behavioral effects, as well are a potential tool for discerning the structure-function relationships underlying AVT's many effects on behavior.

  6. PREVALENCE OF MARKERS OF VIRAL HEPATITIS B AND D FROM HEALTHY POPULATION IN REPUBLIC TYVA

    Directory of Open Access Journals (Sweden)

    T. V. Kozhanova

    2014-01-01

    Full Text Available Aim: to estimate prevalence of markers, genetic diversity, risk factors of HBV and HDV infections in all age groups among healthy population in Republic Tyva. Serum samples obtained from healthy population in Republic Tyva (N = 1086 were tested (aged from birth to older 60 years. The markers of HBV and HDV infections were determined by enzyme immunoassay and PCR. HBsAg was detected in 7,7% (84/1086, anti-HBc — in 47,8% (519/1086 and HBeAg — in 0,3% (3/1086 cases. Prevalence of HBsAg in children under 9 years was 1,3%, no positive results of anti-HDV were determined among children aged up to 9 year. Prevalence of anti-HDV among HBsAg-positive individuals of healthy population was 32,1% (27/84. HBV DNA was detected in 2,9% (31/1086 cases; HDV RNA — in 32,1% (14/84 HBsAg-positive individuals. The obtained data showed high prevalence of HBV ang HDV infections among healthy population of Republic Tyva. Thus, it is necessary to extend screening program in this region to improve viral hepatitis surveillance and diagnostics. The sharp decline in the prevalence of these infections in children up to 9 years in the surveyed endemic region is an evidence of effective protection against HBV and HDV with vaccination against hepatitis B. 

  7. Global patterns of evolutionary distinct and globally endangered amphibians and mammals.

    Directory of Open Access Journals (Sweden)

    Kamran Safi

    Full Text Available BACKGROUND: Conservation of phylogenetic diversity allows maximising evolutionary information preserved within fauna and flora. The "EDGE of Existence" programme is the first institutional conservation initiative that prioritises species based on phylogenetic information. Species are ranked in two ways: one according to their evolutionary distinctiveness (ED and second, by including IUCN extinction status, their evolutionary distinctiveness and global endangerment (EDGE. Here, we describe the global patterns in the spatial distribution of priority ED and EDGE species, in order to identify conservation areas for mammalian and amphibian communities. In addition, we investigate whether environmental conditions can predict the observed spatial pattern in ED and EDGE globally. METHODS AND PRINCIPAL FINDINGS: Priority zones with high concentrations of ED and EDGE scores were defined using two different methods. The overlap between mammal and amphibian zones was very small, reflecting the different phylo-biogeographic histories. Mammal ED zones were predominantly found on the African continent and the neotropical forests, whereas in amphibians, ED zones were concentrated in North America. Mammal EDGE zones were mainly in South-East Asia, southern Africa and Madagascar; for amphibians they were in central and south America. The spatial pattern of ED and EDGE was poorly described by a suite of environmental variables. CONCLUSIONS: Mapping the spatial distribution of ED and EDGE provides an important step towards identifying priority areas for the conservation of mammalian and amphibian phylogenetic diversity in the EDGE of existence programme.

  8. Joint effects of pesticides and ultraviolet-B radiation on amphibian larvae

    International Nuclear Information System (INIS)

    Yu, Shuangying; Wages, Mike; Willming, Morgan; Cobb, George P.; Maul, Jonathan D.

    2015-01-01

    A combination of multiple stressors may be linked to global amphibian declines. Of these, pesticides and UVB radiation co-exposures were examined on the African clawed frog (Xenopus laevis) to provide information that may be useful for amphibian conservation. The independent action model and inferential statistics were used to examine interactions between pesticides (malathion, endosulfan, α-cypermethrin, or chlorothalonil) and environmentally relevant UVB exposures. UVB radiation alone caused 35–68% mortality and nearly 100% of malformations. Pesticides and UVB had additive effects on larval mortality; however, several non-additive effects (antagonistic and synergistic interactions) were observed for total body length. Insecticides mainly affected axial development, whereas UVB radiation caused high incidence of edema, gut malformations, and abnormal tail tips. These results suggest that sublethal developmental endpoints were more sensitive for detecting joint effects. This work has implications for amphibian risk assessments for ecosystems where pesticides and high UVB radiation may co-occur. - Highlights: • Interactive effects of UVB radiation-pesticide co-exposures were examined in frogs. • UVB radiation alone caused 35–68% mortality and nearly 100% of malformations. • Pesticides and UVB had additive effects on larval mortality. • Several non-additive effects were observed for total body length. • Amphibian risk assessments should consider UVB radiation exposure as a co-stressor. - Possible interactions between pesticides and UVB radiation support the idea that amphibian risk assessments should consider these co-stressors when high UVB radiation exposure is high.

  9. Effects of Terrestrial Buffer Zones on Amphibians on Golf Courses

    Science.gov (United States)

    Puglis, Holly J.; Boone, Michelle D.

    2012-01-01

    A major cause of amphibian declines worldwide is habitat destruction or alteration. Public green spaces, such as golf courses and parks, could serve as safe havens to curb the effects of habitat loss if managed in ways to bolster local amphibian communities. We reared larval Blanchard's cricket frogs (Acris blanchardi) and green frogs (Rana clamitans) in golf course ponds with and without 1 m terrestrial buffer zones, and released marked cricket frog metamorphs at the golf course ponds they were reared in. Larval survival of both species was affected by the presence of a buffer zone, with increased survival for cricket frogs and decreased survival for green frogs when reared in ponds with buffer zones. No marked cricket frog juveniles were recovered at any golf course pond in the following year, suggesting that most animals died or migrated. In a separate study, we released cricket frogs in a terrestrial pen and allowed them to choose between mown and unmown grass. Cricket frogs had a greater probability of using unmown versus mown grass. Our results suggest that incorporating buffer zones around ponds can offer suitable habitat for some amphibian species and can improve the quality of the aquatic environment for some sensitive local amphibians. PMID:22761833

  10. Speciation and zoogeography of amphibian in Sundaland

    Directory of Open Access Journals (Sweden)

    Nia Kurniawan

    2015-12-01

    Full Text Available Sundaland is an interesting area to be explored based on its geological history, topography, and climate. Sundaland consists of Penisular Malaysia, Sumatra, Borneo, and Java which experienced some emergence and submergence process in the past. During 1981-2015, most of research in Sundaland found that amphibian family in Sundaland was dominated by Bufonidae, Ranidae, Microhylidae, Megophrydae, Rachophoridae, and Dicroglossidae which experienced lot of speciation in its history. Among of 4 major islands in Sundaland, Borneo has the highest number of species diversity, then Peninsular Malaysia, Sumatra, and Java. During those years, Sumatra and Java got least concern by researcher. Therefore, it is suggested for further study to explore more in Sumatra and Java. Keywords: Sundaland, amphibian, speciation, zoogeography.

  11. Diversity and habitat preferences of amphibians and reptiles in Pakistan: a review

    Directory of Open Access Journals (Sweden)

    Waqas Ali

    2018-06-01

    Full Text Available Geographical position of Pakistan is unique, and country harbors two out of six zoogeographical regions. The country can be divided into 15 habitat types in three major divisions: the mountainous region, foothills, and Indus plains. Overall, 219 species including 24 amphibians and 195 reptiles have been reported so far. Out of these, nine amphibian and 13 reptilian species are endemic to Pakistan. Despite this richness, there is paucity of knowledge regarding diversity of amphibians and reptiles as very few species have been thoroughly studied and very small area has been explored. This has led to the uncertainties regarding distribution and taxonomy of these taxa in the country. The herpetofauna is not protected by law in the country, and their conservation status is yet to be evaluated. Furthermore, distribution ranges of amphibians and reptiles have been changed and systemized survey work is required to update baseline information in the country.

  12. Competency of reptiles and amphibians for eastern equine encephalitis virus.

    Science.gov (United States)

    White, Gregory; Ottendorfer, Christy; Graham, Sean; Unnasch, Thomas R

    2011-09-01

    Eastern equine encephalitis virus (EEEV) is endemic throughout most of the eastern United States. Although it is transmitted year round in Florida, transmission elsewhere is seasonal. The mechanism that enables EEEV to overwinter in seasonal foci remains obscure. In previous field studies, early season EEEV activity was detected in mosquito species that feed primarily upon ectothermic hosts, suggesting that reptiles and amphibians might represent overwintering reservoir hosts for EEEV. To determine if this might be possible, two commonly fed upon amphibian and reptile species were evaluated as hosts for the North American subtype I strain of EEEV. Neither amphibian species was a competent host. However, circulating viremias were detected in both reptile species examined. Hibernating infected garter snakes remained viremic after exiting hibernation. These data suggest that snakes may represent an overwintering host for North American EEEV.

  13. Amphibian distribution patterns in western Europe

    NARCIS (Netherlands)

    Zuiderwijk, Annie

    1980-01-01

    Mechanisms controlling the distribution of amphibians in western Europe have been studied in France where related species, isolated from each other at least during the last glacial period, are now sympatric. Occurrences and biotope preferences of the various species were investigated in several

  14. Factors contributing to amphibian road mortality in a wetland

    Directory of Open Access Journals (Sweden)

    Haijun GU, Qiang DAI, Qian WANG, Yuezhao WANG

    2011-12-01

    Full Text Available To understand road characteristics and landscape features associated with high road mortality of amphibians in Zoige Wetland National Nature Reserve, we surveyed road mortality along four major roads after rainfall in May and September 2007. Road mortality of three species, Rana kukunoris, Nanorana pleskei and Bufo minshanicus, was surveyed across 225 transects (115 in May and 110 in September. Transects were 100 m long and repeated every two kilometers along the four major roads. We used model averaging to assess factors that might determine amphibian road mortality. We recorded an average of 24.6 amphibian road mortalities per kilometer in May and 19.2 in September. Among road characteristics, road width was positively associated with road morality for R. kukunori and B. minshanicus. Traffic volume also increased the road mortality of B. minshanicus in September. Of the landscape features measured, area proportions of three types of grassland (wet, mesic and dry within 1 km of the roads, particularly that of wet grassland, significantly increased road mortality for R. kukunori and total mortality across all three species. To most effectively reduce road mortality of amphibians in the Zoige wetlands, we suggest better road design such as avoiding wet grasslands, minimizing road width, underground passes and traffic control measures. The implementation of public transit in the area would reduce traffic volume, and hence mortality [Current Zoology 57 (6: 768–774, 2011].

  15. Riparian Habitat Management for Reptiles and Amphibians on Corps of Engineers Projects

    National Research Council Canada - National Science Library

    Dickerson, Dena

    2001-01-01

    ... important taxonomic groups such as reptiles and amphibians. This note provides an overview of the importance of riparian habitat at Corps projects for reptiles and amphibians, identifies riparian zone functions and habitat characteristics, provides examples of representative taxa and regional comparisons, and describes impacts of riparian habitat modification.

  16. Ticks infesting amphibians and reptiles in Pernambuco, Northeastern Brazil.

    Science.gov (United States)

    Dantas-Torres, Filipe; Oliveira-Filho, Edmilson F; Soares, Fábio Angelo M; Souza, Bruno O F; Valença, Raul Baltazar P; Sá, Fabrício B

    2008-01-01

    Ticks infesting amphibians and reptiles in the State of Pernambuco are reviewed, based on the current literature and new collections recently carried out by the authors. To date, three tick species have been found on amphibians and reptiles in Pernambuco. Amblyomma fuscum appears to be exclusively associated with Boa constrictor, its type host. Amblyomma rotundatum has a relatively low host-specificity, being found on toads, snakes, and iguana. Amblyomma dissimile has been found on a lizard and also small mammals (i.e., rodents and marsupials). New tick-host associations and locality records are given.

  17. Small Mammals, Reptiles, and Amphibians

    Science.gov (United States)

    Bryce Rickel

    2005-01-01

    This chapter focuses on small mammals, reptiles, and amphibians that inhabit the grasslands within the Southwestern Region of the USDA Forest Service. The chapter is not intended to be an all inclusive list of species, but rather to address the species that play important roles in grassland ecosystems and that often are associated with the management of grasslands....

  18. Headwater Stream Management Dichotomies: Local Amphibian Habitat vs. Downstream Fish Habitat

    Science.gov (United States)

    Jackson, C. R.

    2002-12-01

    Small headwater streams in mountainous areas of the Pacific Northwest often do not harbor fish populations because of low water depth and high gradients. Rather, these streams provide habitat for dense assemblages of stream-dwelling amphibians. A variety of management goals have been suggested for such streams such as encouraging large woody debris recruitment to assist in sediment trapping and valley floor formation, encouraging large woody debris recruitment to provide downstream wood when debris flows occur, providing continuous linear stream buffers within forest harvest areas to provide shade and bank stability, etc. A basic problem with analying the geomorphic or biotic benefits of any of these strategies is the lack of explicit management goals for such streams. Should managers strive to optimize downstream fish habitat, local amphibian habitat, or both? Through observational data and theoretical considerations, it will be shown that these biotic goals will lead to very different geomorphic management recommendations. For instance, woody debris greater than 60 cm diameter may assist in valley floor development, but it is likely to create subsurface channel flow of unknown value to amphibians. Trapping and retention of fine sediments within headwater streams may improve downstream spawning gravels, but degrades stream-dwelling amphibian habitat. In response to the need for descriptive information on habitat and channel morphology specific to small, non-fish-bearing streams in the Pacific Northwest, morphologies and wood frequencies in forty-two first- and second-order forested streams less than four meters wide were surveyed. Frequencies and size distributions of woody debris were compared between small streams and larger fish-bearing streams as well as between second-growth and virgin timber streams. Statistical models were developed to explore dominant factors affecting channel morphology and habitat. Findings suggest geomorphological relationships

  19. An Experimental Test of Buffer Utility as a Technique for Managing Pool-Breeding Amphibians.

    Science.gov (United States)

    Powell, Jessica S Veysey; Babbitt, Kimberly J

    2015-01-01

    Vegetated buffers are used extensively to manage wetland-dependent wildlife. Despite widespread application, buffer utility has not been experimentally validated for most species. To address this gap, we conducted a six-year, landscape-scale experiment, testing how buffers of different widths affect the demographic structure of two amphibian species at 11 ephemeral pools in a working forest of the northeastern U.S. We randomly assigned each pool to one of three treatments (i.e., reference, 100m buffer, 30m buffer) and clearcut to create buffers. We captured all spotted salamanders and wood frogs breeding in each pool and examined the impacts of treatment and hydroperiod on breeding-population abundance, sex ratio, and recapture rate. The negative effects of clearcutting tended to increase as forest-buffer width decreased and be strongest for salamanders and when other stressors were present (e.g., at short-hydroperiod pools). Recapture rates were reduced in the 30m, but not 100m, treatment. Throughout the experiment for frogs, and during the first year post-cut for salamanders, the predicted mean proportion of recaptured adults in the 30m treatment was only 62% and 40%, respectively, of that in the reference treatment. Frog sex ratio and abundance did not differ across treatments, but salamander sex ratios were increasingly male-biased in both cut treatments. By the final year, there were on average, only about 40% and 65% as many females predicted in the 100m and 30m treatments, respectively, compared to the first year. Breeding salamanders at short-hydroperiod pools were about 10% as abundant in the 100m versus reference treatment. Our study demonstrates that buffers partially mitigate the impacts of habitat disturbance on wetland-dependent amphibians, but buffer width and hydroperiod critically mediate that process. We provide the first experimental evidence showing that 30-m-wide buffers may be insufficient for maintaining resilient breeding populations of pool

  20. An Experimental Test of Buffer Utility as a Technique for Managing Pool-Breeding Amphibians.

    Directory of Open Access Journals (Sweden)

    Jessica S Veysey Powell

    Full Text Available Vegetated buffers are used extensively to manage wetland-dependent wildlife. Despite widespread application, buffer utility has not been experimentally validated for most species. To address this gap, we conducted a six-year, landscape-scale experiment, testing how buffers of different widths affect the demographic structure of two amphibian species at 11 ephemeral pools in a working forest of the northeastern U.S. We randomly assigned each pool to one of three treatments (i.e., reference, 100m buffer, 30m buffer and clearcut to create buffers. We captured all spotted salamanders and wood frogs breeding in each pool and examined the impacts of treatment and hydroperiod on breeding-population abundance, sex ratio, and recapture rate. The negative effects of clearcutting tended to increase as forest-buffer width decreased and be strongest for salamanders and when other stressors were present (e.g., at short-hydroperiod pools. Recapture rates were reduced in the 30m, but not 100m, treatment. Throughout the experiment for frogs, and during the first year post-cut for salamanders, the predicted mean proportion of recaptured adults in the 30m treatment was only 62% and 40%, respectively, of that in the reference treatment. Frog sex ratio and abundance did not differ across treatments, but salamander sex ratios were increasingly male-biased in both cut treatments. By the final year, there were on average, only about 40% and 65% as many females predicted in the 100m and 30m treatments, respectively, compared to the first year. Breeding salamanders at short-hydroperiod pools were about 10% as abundant in the 100m versus reference treatment. Our study demonstrates that buffers partially mitigate the impacts of habitat disturbance on wetland-dependent amphibians, but buffer width and hydroperiod critically mediate that process. We provide the first experimental evidence showing that 30-m-wide buffers may be insufficient for maintaining resilient breeding

  1. Spatial and temporal variation in population dynamics of Andean frogs: Effects of forest disturbance and evidence for declines

    Directory of Open Access Journals (Sweden)

    Esther M. Cole

    2014-08-01

    Full Text Available Biodiversity loss is a global phenomenon that can result in the collapse of food webs and critical ecosystem services. Amphibian population decline over the last century is a notable case of species loss because amphibians survived the last four major extinction events in global history, their current rate of extinction is unprecedented, and their rate of extinction is greater than that for most other taxonomic groups. Despite the severity of this conservation problem and its relevance to the study of global biodiversity loss, major knowledge gaps remain for many of the most threatened species and regions in the world. Rigorous estimates of population parameters are lacking for many amphibian species in the Neotropics. The goal of our study was to determine how the demography of seven species of the genus Pristimantis varied over time and space in two cloud forests in the Ecuadorian Andes. We completed a long term capture–mark–recapture study to estimate abundance, survival, and population growth rates in two cloud forests in the Ecuadorian Andes; from 2002 to 2009 at Yanayacu in the Eastern Cordillera and from 2002 to 2003 at Cashca Totoras in the Western Cordillera. Our results showed seasonal and annual variation in population parameters by species and sex. P. bicantus experienced significant reductions in abundance over the course of our study. Abundance, apparent survival, and population growth rates were lower in disturbed than in primary or mature secondary forest. The results of our study raise concerns for the population status of understudied amphibian groups and provide insights into the population dynamics of Neotropical amphibians.

  2. The Amphibian Research and Monitoring Initiative (ARMI): 5-year report

    Science.gov (United States)

    Muths, Erin; Gallant, Alisa L.; Campbell Grant, Evan H.; Battaglin, William A.; Green, David E.; Staiger, Jennifer S.; Walls, Susan C.; Gunzburger, Margaret S.; Kearney, Rick F.

    2006-01-01

    The Amphibian Research and Monitoring Initiative (ARMI) is an innovative, multidisciplinary program that began in 2000 in response to a congressional directive for the Department of the Interior to address the issue of amphibian declines in the United States. ARMI’s formulation was cross-disciplinary, integrating U.S. Geological Survey scientists from Biology, Water, and Geography to develop a course of action (Corn and others, 2005a). The result has been an effective program with diverse, yet complementary, expertise.

  3. Initial diversification of living amphibians predated the breakup of Pangaea

    OpenAIRE

    San Mauro, D.; Vences, M.; Alcobendas, M.; Zardoya, R.; Meyer, A.

    2005-01-01

    The origin and divergence of the three living orders of amphibians (Anura, Caudata, Gymnophiona) and their main lineages are one of the most hotly debated topics in vertebrate evolution. Here, we present a robust molecular phylogeny based on the nuclear RAG1 gene as well as results from a variety of alternative independent molecular clock calibrations. Our analyses suggest that the origin and early divergence of the three living amphibian orders dates back to the Palaeozoic or early Mesozoic,...

  4. Zinc deficiency among a healthy population in Baghdad, Iraq

    International Nuclear Information System (INIS)

    Al-Timimi, D.; Al-Najjar, F.; Al-Sharbatti, Shatha S.

    2005-01-01

    To determine the prevalence of zinc deficiency and the current zinc status among a sample selected from the healthy population in Baghdad, Iraq. We carried out a community-based study in Baghdad City, Iraq from November through June 2002. We selected a sample of 2090 healthy subjects (aged 1 month to 85 years). We used a pre-tested questionnaire, designed to obtain information on gender, birth dates, height, weight, residence, habitual food consumption patterns, and social status. We performed laboratory assessment of serum zinc level, dietary assessment of food frequency and usual zinc intake. We considered subjects with serum zinc concentration of /-7.7 to 12.3 umol/l mild to moderately zinc deficient. The prevalence of zinc deficiency among the studied sample was 2.7%. We found mild to moderate zinc deficiency among 55.7% of the study sample. Dietary zinc intake assessment showed that 74.8% of the studied sample consumed less than the recommended intake, and in 62.3%, the intakes were deficient and grossly deficient. Mean daily zinc ranged from 5.2 mg in children to 8.5 mg in adults. We observed a high prevalence of mild to moderate zinc deficiency, with inadequate dietary zinc intake among a considerable proportion of the studied sample. Zinc supplementation may be an effective public health intervention means to improve the zinc status of the population. (author)

  5. Global Amphibian Extinction Risk Assessment for the Panzootic Chytrid Fungus

    Directory of Open Access Journals (Sweden)

    Matthew C. Fisher

    2009-09-01

    Full Text Available Species are being lost at increasing rates due to anthropogenic effects, leading to the recognition that we are witnessing the onset of a sixth mass extinction. Emerging infectious disease has been shown to increase species loss and any attempts to reduce extinction rates need to squarely confront this challenge. Here, we develop a procedure for identifying amphibian species that are most at risk from the effects of chytridiomycosis by combining spatial analyses of key host life-history variables with the pathogen's predicted distribution. We apply our rule set to the known global diversity of amphibians in order to prioritize pecies that are most at risk of loss from disease emergence. This risk assessment shows where limited conservation funds are best deployed in order to prevent further loss of species by enabling ex situ amphibian salvage operations and focusing any potential disease mitigation projects.

  6. Effects of road salt on larval amphibian susceptibility to parasitism through behavior and immunocompetence.

    Science.gov (United States)

    Milotic, Dino; Milotic, Marin; Koprivnikar, Janet

    2017-08-01

    Large quantities of road salts are used for de-icing in temperate climates but often leach into aquatic ecosystems where they can cause harm to inhabitants, including reduced growth and survival. However, the implications of road salt exposure for aquatic animal susceptibility to pathogens and parasites have not yet been examined even though infectious diseases can significantly contribute to wildlife population declines. Through a field survey, we found a range of NaCl concentrations (50-560mg/L) in ponds known to contain larval amphibians, with lower levels found in sites close to gravel- rather than hard-surfaced roads. We then investigated how chronic exposure to environmentally-realistic levels of road salt (up to 1140mg/L) affected susceptibility to infection by trematode parasites (helminths) in larval stages of two amphibian species (Lithobates sylvaticus - wood frogs, and L. pipiens - northern leopard frogs) by considering effects on host anti-parasite behavior and white blood cell profiles. Wood frogs exposed to road salt had higher parasite loads, and also exhibited reduced anti-parasite behavior in these conditions. In contrast, infection intensity in northern leopard frogs had a non-monotonic response to road salts even though lymphocytes were only elevated at the highest concentration. Our results indicate the potential for chronic road salt exposure to affect larval amphibian susceptibility to pathogenic parasites through alterations of behavior and immunocompetence, with further studies needed at higher concentrations, as well as that of road salts on free-living parasite infectious stages. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Barriers and Facilitators to Healthy Lifestyle Changes in Minority Ethnic Populations in the UK: a Narrative Review.

    Science.gov (United States)

    Patel, Naina; Ferrer, Harriet Batista; Tyrer, Freya; Wray, Paula; Farooqi, Azhar; Davies, Melanie J; Khunti, Kamlesh

    2017-12-01

    Minority ethnic populations experience a disproportionate burden of health inequalities compared with the rest of the population, including an increased risk of type 2 diabetes (T2DM). The purpose of this narrative review was to explore knowledge and attitudes around diabetes, physical activity and diet and identify barriers and facilitators to healthy lifestyle changes in minority ethnic populations in the UK. The narrative review focused on three key research topics in relation to barriers and facilitators to healthy lifestyle changes in minority adult ethnic populations: (i) knowledge and attitudes about diabetes risk; (ii) current behaviours and knowledge about physical activity and diet; and (iii) barriers and facilitators to living a healthier lifestyle. Nearly all of the studies that we identified reported on South Asian minority ethnic populations; we found very few studies on other minority ethnic populations. Among South Asian communities, there was generally a good understanding of diabetes and its associated risk factors. However, knowledge about the levels of physical activity required to gain health benefits was relatively poor and eating patterns varied. Barriers to healthy lifestyle changes identified included language barriers, prioritising work over physical activity to provide for the family, cultural barriers with regard to serving and eating traditional food, different perceptions of a healthy body weight and fear of racial harassment or abuse when exercising. Additional barriers for South Asian women included expectations to remain in the home, fear for personal safety, lack of same gender venues and concerns over the acceptability of wearing 'western' exercise clothing. Facilitators included concern that weight gain might compromise family/carer responsibilities, desire to be healthy, T2DM diagnosis and exercise classes held in 'safe' environments such as places of worship. Our findings suggest that South Asian communities are less likely to

  8. Seasonal differences in extinction and colonization drive occupancy dynamics of an imperilled amphibian.

    Directory of Open Access Journals (Sweden)

    Lea A Randall

    Full Text Available A detailed understanding of the population dynamics of many amphibian species is lacking despite concerns about declining amphibian biodiversity and abundance. This paper explores temporal patterns of occupancy and underlying extinction and colonization dynamics in a regionally imperiled amphibian species, the Northern leopard frog (Lithobates pipiens in Alberta. Our study contributes to elucidating regional occupancy dynamics at northern latitudes, where climate extremes likely have a profound effect on seasonal occupancy. The primary advantage of our study is its wide geographic scale (60,000 km2 and the use of repeat visual surveys each spring and summer from 2009-2013. We find that occupancy varied more dramatically between seasons than years, with low spring and higher summer occupancy. Between spring and summer, colonization was high and extinction low; inversely, colonization was low and extinction high over the winter. The dynamics of extinction and colonization are complex, making conservation management challenging. Our results reveal that Northern leopard frog occupancy was constant over the last five years and thus there is no evidence of decline or recovery within our study area. Changes to equilibrium occupancy are most sensitive to increasing colonization in the spring or declining extinction in the summer. Therefore, conservation and management efforts should target actions that are likely to increase spring colonization; this could be achieved through translocations or improving the quality or access to breeding habitat. Because summer occupancy is already high, it may be difficult to improve further. Nevertheless, summer extinction could be reduced by predator control, increasing water quality or hydroperiod of wetlands, or increasing the quality or quantity of summer habitat.

  9. Seasonal differences in extinction and colonization drive occupancy dynamics of an imperilled amphibian.

    Science.gov (United States)

    Randall, Lea A; Smith, Des H V; Jones, Breana L; Prescott, David R C; Moehrenschlager, Axel

    2015-01-01

    A detailed understanding of the population dynamics of many amphibian species is lacking despite concerns about declining amphibian biodiversity and abundance. This paper explores temporal patterns of occupancy and underlying extinction and colonization dynamics in a regionally imperiled amphibian species, the Northern leopard frog (Lithobates pipiens) in Alberta. Our study contributes to elucidating regional occupancy dynamics at northern latitudes, where climate extremes likely have a profound effect on seasonal occupancy. The primary advantage of our study is its wide geographic scale (60,000 km2) and the use of repeat visual surveys each spring and summer from 2009-2013. We find that occupancy varied more dramatically between seasons than years, with low spring and higher summer occupancy. Between spring and summer, colonization was high and extinction low; inversely, colonization was low and extinction high over the winter. The dynamics of extinction and colonization are complex, making conservation management challenging. Our results reveal that Northern leopard frog occupancy was constant over the last five years and thus there is no evidence of decline or recovery within our study area. Changes to equilibrium occupancy are most sensitive to increasing colonization in the spring or declining extinction in the summer. Therefore, conservation and management efforts should target actions that are likely to increase spring colonization; this could be achieved through translocations or improving the quality or access to breeding habitat. Because summer occupancy is already high, it may be difficult to improve further. Nevertheless, summer extinction could be reduced by predator control, increasing water quality or hydroperiod of wetlands, or increasing the quality or quantity of summer habitat.

  10. Drought, deluge and declines: the impact of precipitation extremes on amphibians in a changing climate

    Science.gov (United States)

    Walls, Susan C.; Barichivich, William J.; Brown, Mary E.

    2013-01-01

    The Class Amphibia is one of the most severely impacted taxa in an on-going global biodiversity crisis. Because amphibian reproduction is tightly associated with the presence of water, climatic changes that affect water availability pose a particularly menacing threat to both aquatic and terrestrial-breeding amphibians. We explore the impacts that one facet of climate change—that of extreme variation in precipitation—may have on amphibians. This variation is manifested principally as increases in the incidence and severity of both drought and major storm events. We stress the need to consider not only total precipitation amounts but also the pattern and timing of rainfall events. Such rainfall “pulses” are likely to become increasingly more influential on amphibians, especially in relation to seasonal reproduction. Changes in reproductive phenology can strongly influence the outcome of competitive and predatory interactions, thus potentially altering community dynamics in assemblages of co-existing species. We present a conceptual model to illustrate possible landscape and metapopulation consequences of alternative climate change scenarios for pond-breeding amphibians, using the Mole Salamander, Ambystoma talpoideum, as an example. Although amphibians have evolved a variety of life history strategies that enable them to cope with environmental uncertainty, it is unclear whether adaptations can keep pace with the escalating rate of climate change. Climate change, especially in combination with other stressors, is a daunting challenge for the persistence of amphibians and, thus, the conservation of global biodiversity.

  11. Effects of two stressors on amphibian larval development.

    Science.gov (United States)

    Stark, Karolina; Scott, David E; Tsyusko, Olga; Coughlin, Daniel P; Hinton, Thomas G

    2012-05-01

    In parallel with a renewed interest in nuclear power and its possible environmental impacts, a new environmental radiation protection system calls for environmental indicators of radiological stress. However, because environmental stressors seldom occur alone, this study investigated the combined effects of an ecological stressor (larval density) and an anthropogenic stressor (ionizing radiation) on amphibians. Scaphiopus holbrookii tadpoles reared at different larval densities were exposed to four low irradiation dose rates (0.13, 2.4, 21, and 222 mGy d(-1)) from (137)Cs during the sensitive period prior to and throughout metamorphosis. Body size at metamorphosis and development rate served as fitness correlates related to population dynamics. Results showed that increased larval density decreased body size but did not affect development rate. Low dose rate radiation had no impact on either endpoint. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Testing the impact of miniaturization on phylogeny: Paleozoic dissorophoid amphibians.

    Science.gov (United States)

    Fröbisch, Nadia B; Schoch, Rainer R

    2009-06-01

    Among the diverse clade of Paleozoic dissorophoid amphibians, the small, terrestrial amphibamids and the neotenic branchiosaurids have frequently been suggested as possible antecedents of either all or some of the modern amphibian clades. Classically, amphibamids and branchiosaurids have been considered to represent distinct, but closely related clades within dissorophoids, but despite their importance for the controversial lissamphibian origins, a comprehensive phylogenetic analysis of small dissorophoids has thus far not been attempted. On the basis of an integrated data set, the relationships of amphibamids and branchiosaurids were analyzed using parsimony and Bayesian approaches. Both groups represent miniaturized forms and it was tested whether similar developmental pathways, associated with miniaturization, lead to an artificial close relationship of branchiosaurids and amphibamids. Moreover, the fit of the resulting tree topologies to the distribution of fossil taxa in the stratigraphic rock record was assessed as an additional source of information. The results show that characters associated with a miniaturized morphology are not responsible for the close clustering of branchiosaurids and amphibamids. Instead, all analyses invariably demonstrate a monophyletic clade of branchiosaurids highly nested within derived amphibamids, indicating that branchiosaurids represent a group of secondarily neotenic amphibamid dissorophoids. This understanding of the phylogenetic relationships of small dissorophoid amphibians provides a new framework for the discussion of their evolutionary history and the evolution of characters shared by branchiosaurids and/or amphibamids with modern amphibian taxa.

  13. Phylogenetically-informed priorities for amphibian conservation.

    Science.gov (United States)

    Isaac, Nick J B; Redding, David W; Meredith, Helen M; Safi, Kamran

    2012-01-01

    The amphibian decline and extinction crisis demands urgent action to prevent further large numbers of species extinctions. Lists of priority species for conservation, based on a combination of species' threat status and unique contribution to phylogenetic diversity, are one tool for the direction and catalyzation of conservation action. We describe the construction of a near-complete species-level phylogeny of 5713 amphibian species, which we use to create a list of evolutionarily distinct and globally endangered species (EDGE list) for the entire class Amphibia. We present sensitivity analyses to test the robustness of our priority list to uncertainty in species' phylogenetic position and threat status. We find that both sources of uncertainty have only minor impacts on our 'top 100' list of priority species, indicating the robustness of the approach. By contrast, our analyses suggest that a large number of Data Deficient species are likely to be high priorities for conservation action from the perspective of their contribution to the evolutionary history.

  14. Phylogenetically-informed priorities for amphibian conservation.

    Directory of Open Access Journals (Sweden)

    Nick J B Isaac

    Full Text Available The amphibian decline and extinction crisis demands urgent action to prevent further large numbers of species extinctions. Lists of priority species for conservation, based on a combination of species' threat status and unique contribution to phylogenetic diversity, are one tool for the direction and catalyzation of conservation action. We describe the construction of a near-complete species-level phylogeny of 5713 amphibian species, which we use to create a list of evolutionarily distinct and globally endangered species (EDGE list for the entire class Amphibia. We present sensitivity analyses to test the robustness of our priority list to uncertainty in species' phylogenetic position and threat status. We find that both sources of uncertainty have only minor impacts on our 'top 100' list of priority species, indicating the robustness of the approach. By contrast, our analyses suggest that a large number of Data Deficient species are likely to be high priorities for conservation action from the perspective of their contribution to the evolutionary history.

  15. Are snake populations in widespread decline?

    Science.gov (United States)

    Reading, C J; Luiselli, L M; Akani, G C; Bonnet, X; Amori, G; Ballouard, J M; Filippi, E; Naulleau, G; Pearson, D; Rugiero, L

    2010-12-23

    Long-term studies have revealed population declines in fishes, amphibians, reptiles, birds and mammals. In birds, and particularly amphibians, these declines are a global phenomenon whose causes are often unclear. Among reptiles, snakes are top predators and therefore a decline in their numbers may have serious consequences for the functioning of many ecosystems. Our results show that, of 17 snake populations (eight species) from the UK, France, Italy, Nigeria and Australia, 11 have declined sharply over the same relatively short period of time with five remaining stable and one showing signs of a marginal increase. Although the causes of these declines are currently unknown, we suspect that they are multi-faceted (such as habitat quality deterioration, prey availability), and with a common cause, e.g. global climate change, at their root.

  16. Detrimental effect of temperature increase on the fitness of an amphibian ( Lissotriton helveticus)

    Science.gov (United States)

    Galloy, Valérie; Denoël, Mathieu

    2010-03-01

    Increases of global temperatures have resulted in measurable shifts in the distribution, phenology and survival of some plant and animal species. However, the mechanisms showing links between global warming and biodiversity declines remain unclear. The aim of this study was to examine whether a key parameter of fitness, i.e. offspring number, could be affected by a temperature increase. To this end, we compared egg-laying traits at naturally occurring temperatures (14 °C, 18 °C and 22 °C) in palmate newts, Lissotriton helveticus. Our study suggests that water temperature increase has a negative effect on the fecundity of female newts. Females lay half as many eggs at high temperatures as they do at low temperatures, which results in a lower number of hatchlings. This study shows that global warming would affect amphibian populations. It complements other studies in pointing out that changes in phenology may not be driven only by warmer earlier temperatures but also by counter-selection during late-breeding, particularly in long-term breeders such as newts. More experimental studies should be carried out to understand the complex consequences of global warming and the proximate mechanisms of amphibian decline.

  17. Two-stage recovery of amphibian assemblages following selective logging of tropical forests.

    Science.gov (United States)

    Adum, Gilbert Baase; Eichhorn, Markus Peter; Oduro, William; Ofori-Boateng, Caleb; Rödel, Mark-Oliver

    2013-04-01

    There is a lack of quantitative information on the effectiveness of selective-logging practices in ameliorating effects of logging on faunal communities. We conducted a large-scale replicated field study in 3 selectively logged moist semideciduous forests in West Africa at varying times after timber extraction to assess post logging effects on amphibian assemblages. Specifically, we assessed whether the diversity, abundance, and assemblage composition of amphibians changed over time for forest-dependent species and those tolerant of forest disturbance. In 2009, we sampled amphibians in 3 forests (total of 48 study plots, each 2 ha) in southwestern Ghana. In each forest, we established plots in undisturbed forest, recently logged forest, and forest logged 10 and 20 years previously. Logging intensity was constant across sites with 3 trees/ha removed. Recently logged forests supported substantially more species than unlogged forests. This was due to an influx of disturbance-tolerant species after logging. Simultaneously Simpson's index decreased, with increased in dominance of a few species. As time since logging increased richness of disturbance-tolerant species decreased until 10 years after logging when their composition was indistinguishable from unlogged forests. Simpson's index increased with time since logging and was indistinguishable from unlogged forest 20 years after logging. Forest specialists decreased after logging and recovered slowly. However, after 20 years amphibian assemblages had returned to a state indistinguishable from that of undisturbed forest in both abundance and composition. These results demonstrate that even with low-intensity logging (≤3 trees/ha) a minimum 20-year rotation of logging is required for effective conservation of amphibian assemblages in moist semideciduous forests. Furthermore, remnant patches of intact forests retained in the landscape and the presence of permanent brooks may aid in the effective recovery of amphibian

  18. Radioactive contamination of amphibian in the Chernobyl zone

    International Nuclear Information System (INIS)

    Bondar'kov, M.D.; Gashchak, S.P.; Goryanaya, Yu.A.

    2002-01-01

    In result of our investigations there was found out, that though there are great variations of accumulation indices of 90 Sr and 137 Cs, there are certain species differences between amphibians. Basing on general ideas, it can be caused by features of nutrition, behavior and ecology of the species. Terrestrial forms accumulate 137 Cs more than water one, and toads have more high indices of 90 Sr accumulation than frogs. It can been expected, that larvae stages of the terrestrial amphibians, due to water living, will have lower parameters of the radionuclide accumulation, than individuals came on dry land. They also must have and more low variation coefficient of TF values. However, it demands to be checked

  19. Special Issue: Viruses Infecting Fish, Amphibians, and Reptiles

    Directory of Open Access Journals (Sweden)

    V. Gregory Chinchar

    2011-09-01

    Full Text Available Although viruses infecting and affecting humans are the focus of considerable research effort, viruses that target other animal species, including cold-blooded vertebrates, are receiving increased attention. In part this reflects the interests of comparative virologists, but increasingly it is based on the impact that many viruses have on ecologically and commercially important animals. Frogs and other amphibians are sentinels of environmental health and their disappearance following viral or fungal (chytrid infection is a cause for alarm. Likewise, because aquaculture and mariculture are providing an increasingly large percentage of the “seafood” consumed by humans, viral agents that adversely impact the harvest of cultured fish and amphibians are of equal concern. [...

  20. Amphibians and reptiles of the state of Chihuahua, Mexico, with comparisons with adjoining states

    Directory of Open Access Journals (Sweden)

    Julio A. Lemos-Espinal

    2017-02-01

    Full Text Available Chihuahua is Mexico’s largest state, and its physiographic complexity affects the distribution of its herpetofauna. We list amphibians and reptiles for the state of Chihuahua, with their conservation status. We also compare this list to those of six adjoining states in the United States and Mexico (New Mexico, Texas, Coahuila, Durango, Sinaloa, and Sonora. A total of 175 species of amphibians and reptiles is found in Chihuahua. Thirty-eight are amphibians, and 137 reptiles. Chihuahuan amphibians and reptiles represent just over 37% of such species from Chihuahua and neighboring states. Chihuahua shares the highest proportion of its herpetofauna with Sonora and Durango. Most of the herpetofauna of Chihuahua falls in IUCNs least concern category and is not listed by SEMARNAT. However, turtles in Chihuahua are a group of particular conservation concern.

  1. Amphibians and reptiles of the state of Chihuahua, Mexico, with comparisons with adjoining states.

    Science.gov (United States)

    Lemos-Espinal, Julio A; Smith, Geoffrey R; Woolrich-Piña, Guillermo A; Cruz, Alexander

    2017-01-01

    Chihuahua is Mexico's largest state, and its physiographic complexity affects the distribution of its herpetofauna. We list amphibians and reptiles for the state of Chihuahua, with their conservation status. We also compare this list to those of six adjoining states in the United States and Mexico (New Mexico, Texas, Coahuila, Durango, Sinaloa, and Sonora). A total of 175 species of amphibians and reptiles is found in Chihuahua. Thirty-eight are amphibians, and 137 reptiles. Chihuahuan amphibians and reptiles represent just over 37% of such species from Chihuahua and neighboring states. Chihuahua shares the highest proportion of its herpetofauna with Sonora and Durango. Most of the herpetofauna of Chihuahua falls in IUCNs least concern category and is not listed by SEMARNAT. However, turtles in Chihuahua are a group of particular conservation concern.

  2. Independent evolution of the sexes promotes amphibian diversification

    Science.gov (United States)

    De Lisle, Stephen P.; Rowe, Locke

    2015-01-01

    Classic ecological theory predicts that the evolution of sexual dimorphism constrains diversification by limiting morphospace available for speciation. Alternatively, sexual selection may lead to the evolution of reproductive isolation and increased diversification. We test contrasting predictions of these hypotheses by examining the relationship between sexual dimorphism and diversification in amphibians. Our analysis shows that the evolution of sexual size dimorphism (SSD) is associated with increased diversification and speciation, contrary to the ecological theory. Further, this result is unlikely to be explained by traditional sexual selection models because variation in amphibian SSD is unlikely to be driven entirely by sexual selection. We suggest that relaxing a central assumption of classic ecological models—that the sexes share a common adaptive landscape—leads to the alternative hypothesis that independent evolution of the sexes may promote diversification. Once the constraints of sexual conflict are relaxed, the sexes can explore morphospace that would otherwise be inaccessible. Consistent with this novel hypothesis, the evolution of SSD in amphibians is associated with reduced current extinction threat status, and an historical reduction in extinction rate. Our work reconciles conflicting predictions from ecological and evolutionary theory and illustrates that the ability of the sexes to evolve independently is associated with a spectacular vertebrate radiation. PMID:25694616

  3. Engineering a future for amphibians under climate change

    Science.gov (United States)

    Shoo, L.P.; Olson, D.H.; Mcmenamin, S.K.; Murray, K.A.; Van Sluys, M.; Donnelly, M.A.; Stratford, D.; Terhivuo, J.; Merino-Viteri, A.; Herbert, S.M.; Bishop, P.J.; Corn, P.S.; Dovey, L.; Griffiths, R.A.; Lowe, K.; Mahony, M.; McCallum, H.; Shuker, J.D.; Simpkins, C.; Skerratt, L.F.; Williams, S.E.; Hero, J.-M.

    2011-01-01

    1. Altered global climates in the 21st century pose serious threats for biological systems and practical actions are needed to mount a response for species at risk. 2. We identify management actions from across the world and from diverse disciplines that are applicable to minimizing loss of amphibian biodiversity under climate change. Actions were grouped under three thematic areas of intervention: (i) installation of microclimate and microhabitat refuges; (ii) enhancement and restoration of breeding sites; and (iii) manipulation of hydroperiod or water levels at breeding sites. 3. Synthesis and applications. There are currently few meaningful management actions that will tangibly impact the pervasive threat of climate change on amphibians. A host of potentially useful but poorly tested actions could be incorporated into local or regional management plans, programmes and activities for amphibians. Examples include: installation of irrigation sprayers to manipulate water potentials at breeding sites; retention or supplementation of natural and artificial shelters (e.g. logs, cover boards) to reduce desiccation and thermal stress; manipulation of canopy cover over ponds to reduce water temperature; and, creation of hydrologoically diverse wetland habitats capable of supporting larval development under variable rainfall regimes. We encourage researchers and managers to design, test and scale up new initiatives to respond to this emerging crisis.

  4. A checklist of the reptiles and amphibians found in protected areas along the South African Wild Coast, with notes on conservation implications

    Directory of Open Access Journals (Sweden)

    Jan A. Venter

    2015-11-01

    Full Text Available We surveyed six protected areas along the Wild Coast of the Eastern Cape, South Africa, to determine general herpetofaunal diversity as well as the representation of species of special conservation concern. Visual encounter survey methods and standard Y-shape trap arrays were used to conduct surveys from 2011 to 2013. A total of 59 species (22 amphibians and 37 reptiles were recorded. A number of previously unknown populations of threatened species and one potential novel species were discovered in these protected areas, and the known ranges of several other species were extended. A total of 243 quarter-degree grid-cell unit records were documented, of which 90 (23% amphibians and 50% reptiles represented the first records for the area. Amphibian and reptile diversity increased along the coast and a number of species of conservation concern were well represented in current protected areas. Our study provides a comprehensive amphibian and reptile checklist for an under-sampled region and highlights the importance of baseline data for improving conservation management. Conservation implications: Small protected areas play an important role in conserving a number of threatened herpetofaunal species along the Wild Coast. The region is currently under significant and increasing pressure from anthropogenic-induced environmental degradation, which affects biodiversity and subsequently the local inhabitants. The information presented here represents an important baseline for future conservation management.

  5. Effects of atrazine on fish, amphibians, and aquatic reptiles: a critical review.

    Science.gov (United States)

    Solomon, Keith R; Carr, James A; Du Preez, Louis H; Giesy, John P; Kendall, Ronald J; Smith, Ernest E; Van Der Kraak, Glen J

    2008-01-01

    The herbicide atrazine is widely used in agriculture for the production of corn and other crops. Because of its physical and chemical properties, atrazine is found in small concentrations in surface waters--habitats for some species. A number of reports on the effects of atrazine on aquatic vertebrates, mostly amphibians, have been published, yet there is inconsistency in the effects reported, and inconsistency between studies in different laboratories. We have brought the results and conclusions of all of the relevant laboratory and field studies together in this critical review and assessed causality using procedures for the identification of causative agents of disease and ecoepidemiology derived from Koch's postulates and the Bradford-Hill guidelines. Based on a weight of evidence analysis of all of the data, the central theory that environmentally relevant concentrations of atrazine affect reproduction and/or reproductive development in fish, amphibians, and reptiles is not supported by the vast majority of observations. The same conclusions also hold for the supporting theories such as induction of aromatase, the enzyme that converts testosterone to estradiol. For other responses, such as immune function, stress endocrinology, parasitism, or population-level effects, there are no indications of effects or there is such a paucity of good data that definitive conclusions cannot be made.

  6. Arginine Vasotocin, the Social Neuropeptide of Amphibians and Reptiles

    Science.gov (United States)

    Wilczynski, Walter; Quispe, Maricel; Muñoz, Matías I.; Penna, Mario

    2017-01-01

    Arginine vasotocin (AVT) is the non-mammalian homolog of arginine vasopressin (AVP) and, like vasopressin, serves as an important modulator of social behavior in addition to its peripheral functions related to osmoregulation, reproductive physiology, and stress hormone release. In amphibians and reptiles, the neuroanatomical organization of brain AVT cells and fibers broadly resembles that seen in mammals and other taxa. Both parvocellular and magnocellular AVT-containing neurons are present in multiple populations located mainly in the basal forebrain from the accumbens–amygdala area to the preoptic area and hypothalamus, from which originate widespread fiber connections spanning the brain with a particularly heavy innervation of areas associated with social behavior and decision-making. As for mammalian AVP, AVT is present in greater amounts in males in many brain areas, and its presence varies seasonally, with hormonal state, and in males with differing social status. AVT’s social influence is also conserved across herpetological taxa, with significant effects on social signaling and aggression, and, based on the very small number of studies investigating more complex social behaviors in amphibians and reptiles, AVT may also modulate parental care and social bonding when it is present in these vertebrates. Within this conserved pattern, however, both AVT anatomy and social behavior effects vary significantly across species. Accounting for this diversity represents a challenge to understanding the mechanisms by which AVT exerts its behavioral effects, as well are a potential tool for discerning the structure-function relationships underlying AVT’s many effects on behavior. PMID:28824546

  7. Arginine Vasotocin, the Social Neuropeptide of Amphibians and Reptiles

    Directory of Open Access Journals (Sweden)

    Walter Wilczynski

    2017-08-01

    Full Text Available Arginine vasotocin (AVT is the non-mammalian homolog of arginine vasopressin (AVP and, like vasopressin, serves as an important modulator of social behavior in addition to its peripheral functions related to osmoregulation, reproductive physiology, and stress hormone release. In amphibians and reptiles, the neuroanatomical organization of brain AVT cells and fibers broadly resembles that seen in mammals and other taxa. Both parvocellular and magnocellular AVT-containing neurons are present in multiple populations located mainly in the basal forebrain from the accumbens–amygdala area to the preoptic area and hypothalamus, from which originate widespread fiber connections spanning the brain with a particularly heavy innervation of areas associated with social behavior and decision-making. As for mammalian AVP, AVT is present in greater amounts in males in many brain areas, and its presence varies seasonally, with hormonal state, and in males with differing social status. AVT’s social influence is also conserved across herpetological taxa, with significant effects on social signaling and aggression, and, based on the very small number of studies investigating more complex social behaviors in amphibians and reptiles, AVT may also modulate parental care and social bonding when it is present in these vertebrates. Within this conserved pattern, however, both AVT anatomy and social behavior effects vary significantly across species. Accounting for this diversity represents a challenge to understanding the mechanisms by which AVT exerts its behavioral effects, as well are a potential tool for discerning the structure-function relationships underlying AVT’s many effects on behavior.

  8. Inventory of Amphibians and Reptiles at Mojave National Preserve: Final Report

    Science.gov (United States)

    Persons, Trevor B.; Nowak, Erika M.

    2007-01-01

    As part of the National Park Service Inventory and Monitoring Program in the Mojave Network, we conducted an inventory of amphibians and reptiles at Mojave National Preserve in 2004-2005. Objectives for this inventory were to use fieldwork, museum collections, and literature review to document the occurrence of reptile and amphibian species occurring at MOJA. Our goals were to document at least 90% of the species present, provide one voucher specimen for each species identified, provide GIS-referenced distribution information for sensitive species, and provide all deliverables, including NPSpecies entries, as outlined in the Mojave Network Biological Inventory Study Plan. Methods included daytime and nighttime visual encounter surveys and nighttime road driving. Survey effort was concentrated in predetermined priority sampling areas, as well as in areas with a high potential for detecting undocumented species. We recorded 31 species during our surveys. During literature review and museum specimen database searches, we found records for seven additional species from MOJA, elevating the documented species list to 38 (two amphibians and 36 reptiles). Based on our surveys, as well as literature and museum specimen review, we estimate an overall inventory completeness of 95% for Mojave National Preserve herpetofauna; 67% for amphibians and 97% for reptiles.

  9. Working Memory Training in Schizophrenia and Healthy Populations

    Directory of Open Access Journals (Sweden)

    Linette Lawlor-Savage

    2014-09-01

    Full Text Available Cognitive deficits are consistently demonstrated in individuals with schizophrenia. Cognitive training involves structured exercises prescribed and undertaken with the intention of enhancing cognitive abilities such as attention, memory, and problem solving. Thus, cognitive training represents a potentially promising intervention for enhancing cognitive abilities in schizophrenia. However, cognitive training programs are numerous and heterogeneous, hence, the generalizability of training related outcomes can be challenging to assess. This article will provide a brief overview of current literature on cognitive training and explore how knowledge of working memory training in healthy populations can potentially be applied to enhance cognitive functioning of individuals with schizophrenia.

  10. Transcranial Doppler velocities in a large, healthy population.

    Science.gov (United States)

    Tegeler, Charles H; Crutchfield, Kevin; Katsnelson, Michael; Kim, Jongyeol; Tang, Rong; Passmore Griffin, Leah; Rundek, Tanja; Evans, Greg

    2013-07-01

    Transcranial Doppler (TCD) ultrasonography has been extensively used in the evaluation and management of patients with cerebrovascular disease since the clinical application was first described in 1982 by Aaslid and colleagues TCD is a painless, safe, and noninvasive diagnostic technique that measures blood flow velocity in various cerebral arteries. Numerous commercially available TCD devices are currently approved for use worldwide, and TCD is recognized to have an established clinical value for a variety of clinical indications and settings. Although many studies have reported normal values, there have been few recently, and none to include a large cohort of healthy subjects across age, race, and gender. As more objective, automated processes are being developed to assist with the performance and interpretation of TCD studies, and with the potential to easily compare results against a reference population, it is important to define stable normal values and variances across age, race, and gender, with clear understanding of variability of the measurements, as well as the yield from various anatomic segments. To define normal TCD values in a healthy population, we enrolled 364 healthy subjects, ages 18-80 years, to have a complete, nonimaging TCD examination. Subjects with known or suspected cerebrovascular disorders, systemic disorders with cerebrovascular effects, as well as those with known hypertension, diabetes, stroke, coronary artery disease, or myocardial infarction, were excluded. Self-reported ethnicity, handedness, BP, and BMI were recorded. A complete TCD examination was performed by a single experienced sonographer, using a single gate nonimaging TCD device, and a standardized protocol to interrogate up to 23 arterial segments. Individual Doppler spectra were saved for each segment, with velocity and pulsatility index (PI) values calculated using the instrument's automated waveform tracking function. Descriptive analysis was done to determine the mean

  11. Small Demodex populations colonize most parts of the skin of healthy dogs.

    Science.gov (United States)

    Ravera, Iván; Altet, Laura; Francino, Olga; Sánchez, Armand; Roldán, Wendy; Villanueva, Sergio; Bardagí, Mar; Ferrer, Lluís

    2013-02-01

    It is unproven that all dogs harbour Demodex mites in their skin. In fact, several microscopic studies have failed to demonstrate mites in healthy dogs. Demodex canis is a normal inhabitant of the skin of most, if not all, dogs. This hypothesis was tested using a sensitive real-time PCR to detect Demodex DNA in the skin of dogs. One hundred dogs living in a humane society shelter, 20 privately owned and healthy dogs and eight dogs receiving immunosuppressive or antineoplastic therapy. Hair samples (250-300 hairs with their hair bulbs) were taken from five or 20 skin locations. A real-time PCR that amplifies a 166 bp sequence of the D. canis chitin synthase gene was used. The percentage of positive dogs increased with the number of sampling points. When a large canine population was sampled at five cutaneous locations, 18% of dogs were positive for Demodex DNA. When 20 skin locations were sampled, all dogs tested positive for mite DNA. Our study indicates that Demodex colonization of the skin is present in all dogs, independent of age, sex, breed or coat. Nevertheless, the population of mites in a healthy dog appears to be small. Demodex DNA was amplified from all 20 cutaneous points investigated, without statistically significant differences. Using a real-time PCR technique, Demodex mites, albeit in very low numbers, were found to be normal inhabitants of haired areas of the skin of healthy dogs. © 2013 The Authors. Veterinary Dermatology © 2013 ESVD and ACVD.

  12. Can we enhance amphibians? habitat restoration in the post-mining areas?

    OpenAIRE

    Klimaszewski, Krzysztof; Pacholik, Ewa; Snopek, Adam

    2015-01-01

    The study was aimed to evaluate the selected improvements of nature restoration in a depleted gravel pit. The study site consisted of four water reservoirs of different shapes and sizes, flooded after the gravel extraction ended. Ecological succession monitoring, conducted by the Warsaw University of Life Sciences students associated in the Student Scientific Association of Animal Sciences Faculty since the completion of mining, have focused on amphibians. A twofold approach upheld amphibian ...

  13. The link between rapid enigmatic amphibian decline and the globally emerging chytrid fungus.

    Science.gov (United States)

    Lötters, Stefan; Kielgast, Jos; Bielby, Jon; Schmidtlein, Sebastian; Bosch, Jaime; Veith, Michael; Walker, Susan F; Fisher, Matthew C; Rödder, Dennis

    2009-09-01

    Amphibians are globally declining and approximately one-third of all species are threatened with extinction. Some of the most severe declines have occurred suddenly and for unknown reasons in apparently pristine habitats. It has been hypothesized that these "rapid enigmatic declines" are the result of a panzootic of the disease chytridiomycosis caused by globally emerging amphibian chytrid fungus. In a Species Distribution Model, we identified the potential distribution of this pathogen. Areas and species from which rapid enigmatic decline are known significantly overlap with those of highest environmental suitability to the chytrid fungus. We confirm the plausibility of a link between rapid enigmatic decline in worldwide amphibian species and epizootic chytridiomycosis.

  14. Defining normal liver stiffness range in a normal healthy Chinese population without liver disease.

    Directory of Open Access Journals (Sweden)

    James Fung

    Full Text Available BACKGROUND: For patients with chronic liver disease, different optimal liver stiffness cut-off values correspond to different stages of fibrosis, which are specific for the underlying liver disease and population. AIMS: To establish the normal ranges of liver stiffness in the healthy Chinese population without underlying liver disease. METHODS: This is a prospective cross sectional study of 2,528 healthy volunteers recruited from the general population and the Red Cross Transfusion Center in Hong Kong. All participants underwent a comprehensive questionnaire survey, measurement of weight, height, and blood pressure. Fasting liver function tests, glucose and cholesterol was performed. Abdominal ultrasound and transient elastography were performed on all participants. RESULTS: Of the 2,528 subjects, 1,998 were excluded with either abnormal liver parenchyma on ultrasound, chronic medical condition, abnormal blood tests including liver enzymes, fasting glucose, fasting cholesterol, high body mass index, high blood pressure, or invalid liver stiffness scan. The reference range for the 530 subjects without known liver disease was 2.3 to 5.9 kPa (mean 4.1, SD 0.89. The median liver stiffness was higher in males compared with females (4.3 vs 4.0 kPa respectively, p55 years (p=0.001. CONCLUSIONS: The healthy reference range for liver stiffness in the Chinese population is 2.3 to 5.9 kPa. Female gender and older age group was associated with a lower median liver stiffness.

  15. Life history tactics shape amphibians' demographic responses to the North Atlantic Oscillation.

    Science.gov (United States)

    Cayuela, Hugo; Joly, Pierre; Schmidt, Benedikt R; Pichenot, Julian; Bonnaire, Eric; Priol, Pauline; Peyronel, Olivier; Laville, Mathias; Besnard, Aurélien

    2017-11-01

    Over the last three decades, climate abnormalities have been reported to be involved in biodiversity decline by affecting population dynamics. A growing number of studies have shown that the North Atlantic Oscillation (NAO) influences the demographic parameters of a wide range of plant and animal taxa in different ways. Life history theory could help to understand these different demographic responses to the NAO. Indeed, theory states that the impact of weather variation on a species' demographic traits should depend on its position along the fast-slow continuum. In particular, it is expected that NAO would have a higher impact on recruitment than on adult survival in slow species, while the opposite pattern is expected occur in fast species. To test these predictions, we used long-term capture-recapture datasets (more than 15,000 individuals marked from 1965 to 2015) on different surveyed populations of three amphibian species in Western Europe: Triturus cristatus, Bombina variegata, and Salamandra salamandra. Despite substantial intraspecific variation, our study revealed that these three species differ in their position on a slow-fast gradient of pace of life. Our results also suggest that the differences in life history tactics influence amphibian responses to NAO fluctuations: Adult survival was most affected by the NAO in the species with the fastest pace of life (T. cristatus), whereas recruitment was most impacted in species with a slower pace of life (B. variegata and S. salamandra). In the context of climate change, our findings suggest that the capacity of organisms to deal with future changes in NAO values could be closely linked to their position on the fast-slow continuum. © 2017 John Wiley & Sons Ltd.

  16. Using monitoring data to map amphibian breeding hotspots and describe wetland vulnerability in Yellowstone and Grand Teton National Parks

    Science.gov (United States)

    Ray, Andrew M.; Legg, Kristin; Sepulveda, Adam; Hossack, Blake R.; Patla, Debra

    2015-01-01

    Amphibians have been selected as a “vital sign” by several National Park Service (NPS) Inventory and Monitoring (I&M) networks. An eight-year amphibian monitoring data set provided opportunities to examine spatial and temporal patterns in amphibian breeding richness and wetland desiccation across Yellowstone and Grand Teton National Parks. Amphibian breeding richness was variable across both parks and only four of 31 permanent monitoring catchments contained all four widely distributed species. Annual breeding richness was also variable through time and fluctuated by as much as 75% in some years and catchments. Wetland desiccation was also documented across the region, but alone did not explain variations in amphibian richness. High annual variability across the region emphasizes the need for multiple years of monitoring to accurately describe amphibian richness and wetland desiccation dynamics.

  17. Exotic Fish in Exotic Plantations: A Multi-Scale Approach to Understand Amphibian Occurrence in the Mediterranean Region.

    Directory of Open Access Journals (Sweden)

    Joana Cruz

    Full Text Available Globally, amphibian populations are threatened by a diverse range of factors including habitat destruction and alteration. Forestry practices have been linked with low diversity and abundance of amphibians. The effect of exotic Eucalyptus spp. plantations on amphibian communities has been studied in a number of biodiversity hotspots, but little is known of its impact in the Mediterranean region. Here, we identify the environmental factors influencing the presence of six species of amphibians (the Caudata Pleurodeles waltl, Salamandra salamandra, Lissotriton boscai, Triturus marmoratus and the anurans Pelobates cultripes and Hyla arborea/meridionalis occupying 88 ponds. The study was conducted in a Mediterranean landscape dominated by eucalypt plantations alternated with traditional use (agricultural, montados and native forest at three different scales: local (pond, intermediate (400 metres radius buffer and broad (1000 metres radius buffer. Using the Akaike Information Criterion for small samples (AICc, we selected the top-ranked models for estimating the probability of occurrence of each species at each spatial scale separately and across all three spatial scales, using a combination of covariates from the different magnitudes. Models with a combination of covariates at the different spatial scales had a stronger support than those at individual scales. The presence of predatory fish in a pond had a strong effect on Caudata presence. Permanent ponds were selected by Hyla arborea/meridionalis over temporary ponds. Species occurrence was not increased by a higher density of streams, but the density of ponds impacted negatively on Lissotriton boscai. The proximity of ponds occupied by their conspecifics had a positive effect on the occurrence of Lissotriton boscai and Pleurodeles waltl. Eucalypt plantations had a negative effect on the occurrence of the newt Lissotriton boscai and anurans Hyla arborea/meridionalis, but had a positive effect on

  18. Comparative morphometry of facial surface models obtained from a stereo vision system in a healthy population

    Science.gov (United States)

    López, Leticia; Gastélum, Alfonso; Chan, Yuk Hin; Delmas, Patrice; Escorcia, Lilia; Márquez, Jorge

    2014-11-01

    Our goal is to obtain three-dimensional measurements of craniofacial morphology in a healthy population, using standard landmarks established by a physical-anthropology specialist and picked from computer reconstructions of the face of each subject. To do this, we designed a multi-stereo vision system that will be used to create a data base of human faces surfaces from a healthy population, for eventual applications in medicine, forensic sciences and anthropology. The acquisition process consists of obtaining the depth map information from three points of views, each depth map is obtained from a calibrated pair of cameras. The depth maps are used to build a complete, frontal, triangular-surface representation of the subject face. The triangular surface is used to locate the landmarks and the measurements are analyzed with a MATLAB script. The classification of the subjects was done with the aid of a specialist anthropologist that defines specific subject indices, according to the lengths, areas, ratios, etc., of the different structures and the relationships among facial features. We studied a healthy population and the indices from this population will be used to obtain representative averages that later help with the study and classification of possible pathologies.

  19. Whether the weather drives patterns of endemic amphibian chytridiomycosis: a pathogen proliferation approach.

    Directory of Open Access Journals (Sweden)

    Kris A Murray

    Full Text Available The pandemic amphibian disease chytridiomycosis often exhibits strong seasonality in both prevalence and disease-associated mortality once it becomes endemic. One hypothesis that could explain this temporal pattern is that simple weather-driven pathogen proliferation (population growth is a major driver of chytridiomycosis disease dynamics. Despite various elaborations of this hypothesis in the literature for explaining amphibian declines (e.g., the chytrid thermal-optimum hypothesis it has not been formally tested on infection patterns in the wild. In this study we developed a simple process-based model to simulate the growth of the pathogen Batrachochytrium dendrobatidis (Bd under varying weather conditions to provide an a priori test of a weather-linked pathogen proliferation hypothesis for endemic chytridiomycosis. We found strong support for several predictions of the proliferation hypothesis when applied to our model species, Litoria pearsoniana, sampled across multiple sites and years: the weather-driven simulations of pathogen growth potential (represented as a growth index in the 30 days prior to sampling; GI30 were positively related to both the prevalence and intensity of Bd infections, which were themselves strongly and positively correlated. In addition, a machine-learning classifier achieved ~72% success in classifying positive qPCR results when utilising just three informative predictors 1 GI30, 2 frog body size and 3 rain on the day of sampling. Hence, while intrinsic traits of the individuals sampled (species, size, sex and nuisance sampling variables (rainfall when sampling influenced infection patterns obtained when sampling via qPCR, our results also strongly suggest that weather-linked pathogen proliferation plays a key role in the infection dynamics of endemic chytridiomycosis in our study system. Predictive applications of the model include surveillance design, outbreak preparedness and response, climate change scenario

  20. Whether the weather drives patterns of endemic amphibian chytridiomycosis: a pathogen proliferation approach.

    Science.gov (United States)

    Murray, Kris A; Skerratt, Lee F; Garland, Stephen; Kriticos, Darren; McCallum, Hamish

    2013-01-01

    The pandemic amphibian disease chytridiomycosis often exhibits strong seasonality in both prevalence and disease-associated mortality once it becomes endemic. One hypothesis that could explain this temporal pattern is that simple weather-driven pathogen proliferation (population growth) is a major driver of chytridiomycosis disease dynamics. Despite various elaborations of this hypothesis in the literature for explaining amphibian declines (e.g., the chytrid thermal-optimum hypothesis) it has not been formally tested on infection patterns in the wild. In this study we developed a simple process-based model to simulate the growth of the pathogen Batrachochytrium dendrobatidis (Bd) under varying weather conditions to provide an a priori test of a weather-linked pathogen proliferation hypothesis for endemic chytridiomycosis. We found strong support for several predictions of the proliferation hypothesis when applied to our model species, Litoria pearsoniana, sampled across multiple sites and years: the weather-driven simulations of pathogen growth potential (represented as a growth index in the 30 days prior to sampling; GI30) were positively related to both the prevalence and intensity of Bd infections, which were themselves strongly and positively correlated. In addition, a machine-learning classifier achieved ~72% success in classifying positive qPCR results when utilising just three informative predictors 1) GI30, 2) frog body size and 3) rain on the day of sampling. Hence, while intrinsic traits of the individuals sampled (species, size, sex) and nuisance sampling variables (rainfall when sampling) influenced infection patterns obtained when sampling via qPCR, our results also strongly suggest that weather-linked pathogen proliferation plays a key role in the infection dynamics of endemic chytridiomycosis in our study system. Predictive applications of the model include surveillance design, outbreak preparedness and response, climate change scenario modelling and

  1. Amphibians and reptiles of C. E. Miller Ranch and the Sierra Vieja, Chihuahuan Desert, Texas, USA

    Directory of Open Access Journals (Sweden)

    Drew R. Davis

    2018-02-01

    Full Text Available We report the occurrence of 50 species of amphibians and reptiles recently collected on C. E. Miller Ranch and the Sierra Vieja in the Chihuahuan Desert of Texas, USA and describe their perceived distribution and abundance across various habitat associations of the region. Our recent surveys follow intense, historic sampling of amphibians and reptiles from this region in 1948. Of the 50 species detected in recent surveys, six were not collected in 1948 and an additional three species documented in 1948 have yet to be detected in a 14-year period of recent surveys. Combining data from both historic and recent surveys, a total of 53 species of amphibians and reptiles are known from the ranch (11 amphibians, 42 reptiles. Land stewardship and conservation practices have likely contributed to the persistence of the majority of these species through time. Additionally, we discuss the status of amphibians and reptiles not collected during recent surveys and comment on potential species that have not yet been detected.

  2. Amphibians and reptiles of C. E. Miller Ranch and the Sierra Vieja, Chihuahuan Desert, Texas, USA.

    Science.gov (United States)

    Davis, Drew R; LaDuc, Travis J

    2018-01-01

    We report the occurrence of 50 species of amphibians and reptiles recently collected on C. E. Miller Ranch and the Sierra Vieja in the Chihuahuan Desert of Texas, USA and describe their perceived distribution and abundance across various habitat associations of the region. Our recent surveys follow intense, historic sampling of amphibians and reptiles from this region in 1948. Of the 50 species detected in recent surveys, six were not collected in 1948 and an additional three species documented in 1948 have yet to be detected in a 14-year period of recent surveys. Combining data from both historic and recent surveys, a total of 53 species of amphibians and reptiles are known from the ranch (11 amphibians, 42 reptiles). Land stewardship and conservation practices have likely contributed to the persistence of the majority of these species through time. Additionally, we discuss the status of amphibians and reptiles not collected during recent surveys and comment on potential species that have not yet been detected.

  3. Geomorphology Drives Amphibian Beta Diversity in Atlantic Forest Lowlands of Southeastern Brazil

    OpenAIRE

    Luiz, Amom Mendes; Le?o-Pires, Thiago Augusto; Sawaya, Ricardo J.

    2016-01-01

    Beta diversity patterns are the outcome of multiple processes operating at different scales. Amphibian assemblages seem to be affected by contemporary climate and dispersal-based processes. However, historical processes involved in present patterns of beta diversity remain poorly understood. We assess and disentangle geomorphological, climatic and spatial drivers of amphibian beta diversity in coastal lowlands of the Atlantic Forest, southeastern Brazil. We tested the hypothesis that geomorph...

  4. Terrestrial exposure and effects of Headline AMP(®) Fungicide on amphibians.

    Science.gov (United States)

    Cusaac, J Patrick W; Mimbs, William H; Belden, Jason B; Smith, Loren M; McMurry, Scott T

    2015-08-01

    Recent studies have demonstrated that a pyraclostrobin-containing fungicide (Headline(®) Fungicide--Headline(®) Fungicide and Headline AMP(®) Fungicide are registered trademarks of BASF) is toxic to amphibians at environmentally relevant concentrations. However, these studies were performed in a laboratory setting of a worst-case direct exposure in clean media. Interception of spray by the crop canopy and ground cover used by animals for security cover will influence exposure. Thus, risk to amphibians is unclear in an environmentally realistic field environment. We tested exposure and toxicity of Headline AMP(®) Fungicide to amphibians in multiple agricultural habitat scenarios (e.g., within treated crop vs. grassy areas adjacent to crop) and at two rates during routine aerial application. Specifically, we placed Woodhouse's toads (Bufo woodhousii) and Blanchard's cricket frogs (Acris blanchardi) in enclosures located within treated and untreated corn (VT stage, approximate height = 3 m), and in the potential drift area (adjacent to treated corn) during aerial application of Headline AMP Fungicide at either 731 or 1052 ml/ha (70 and 100 % the maximum application rate in corn, respectively). Mean concentrations of pyraclostrobin measured at ground level were ≤19 % of nominal application rate in all areas. Overall, mean mortality of recovered individuals of both species was ≤15 %, and mortality within Headline AMP Fungicide-treated corn (where risk was anticipated to be highest) was <10 %. It is important to understand that application timing, interception by the crop canopy (which varies both within and between crop systems), and timing of amphibian presence in the crop field influences risk of exposure and effects; however, our results demonstrate that amphibians inhabiting VT stage corn during routine aerial application of Headline AMP Fungicide are at low risk for acute mortality, matching existing laboratory results from acute toxicity studies of

  5. Phylogenic aspects of the amphibian dual olfactory system.

    Science.gov (United States)

    Taniguchi, Kazumi; Saito, Shouichiro; Oikawa, Toshihiro; Taniguchi, Kazuyuki

    2008-01-01

    The phylogenic significance of the subdivision of dual olfactory system is reviewed mainly on the basis of our findings by electron microscopy and lectin histochemistry in the three amphibian species. The dual olfactory system is present in common in these species and consists of the projection from the olfactory epithelium (OE) to the main olfactory bulb (MOB) and that from the vomeronasal epithelium (VNE) to the accessory olfactory bulb (AOB). The phylogenic significance of subdivisions in the dual olfactory system in the amphibian must differently be interpreted. The subdivision of the MOB into its dorsal region (D-MOB) and ventral region (V-MOB) in Xenopus laevis must be attributed to the primitive features in their olfactory receptors. The middle cavity epithelium lining the middle cavity of this frog possesses both ciliated sensory cells and microvillous sensory cells, reminding the OE in fish. The subdivision of the AOB into the rostral (R-AOB) and caudal part (C-AOB) in Bufo japonicus formosus must be regarded as an advanced characteristic. The lack of subdivisions in both MOB and AOB in Cynops pyrrhogaster may reflect their phylogenic primitiveness. Since our lectin histochemistry to detect glycoconjugates expressed in the olfactory pathway reveals the subdivisions in the dual olfactory system in the amphibian, the glycoconjugates may deeply participate in the organization and function of olfactory pathways in phylogeny.

  6. Initial diversification of living amphibians predated the breakup of Pangaea.

    Science.gov (United States)

    San Mauro, Diego; Vences, Miguel; Alcobendas, Marina; Zardoya, Rafael; Meyer, Axel

    2005-05-01

    The origin and divergence of the three living orders of amphibians (Anura, Caudata, Gymnophiona) and their main lineages are one of the most hotly debated topics in vertebrate evolution. Here, we present a robust molecular phylogeny based on the nuclear RAG1 gene as well as results from a variety of alternative independent molecular clock calibrations. Our analyses suggest that the origin and early divergence of the three living amphibian orders dates back to the Palaeozoic or early Mesozoic, before the breakup of Pangaea, and soon after the divergence from lobe-finned fishes. The resulting new biogeographic scenario, age estimate, and the inferred rapid divergence of the three lissamphibian orders may account for the lack of fossils that represent plausible ancestors or immediate sister taxa of all three orders and the heretofore paradoxical distribution of some amphibian fossil taxa. Furthermore, the ancient and rapid radiation of the three lissamphibian orders likely explains why branch lengths connecting their early nodes are particularly short, thus rendering phylogenetic inference of implicated relationships especially difficult.

  7. Managing Amphibian Disease with Skin Microbiota.

    Science.gov (United States)

    Woodhams, Douglas C; Bletz, Molly; Kueneman, Jordan; McKenzie, Valerie

    2016-03-01

    The contribution of emerging amphibian diseases to the sixth mass extinction is driving innovative wildlife management strategies, including the use of probiotics. Bioaugmentation of the skin mucosome, a dynamic environment including host and microbial components, may not provide a generalized solution. Multi-omics technologies and ecological context underlie effective implementation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Amphibian and reptile records from around the Betsiboka Delta area in North-Western Madagascar

    NARCIS (Netherlands)

    Rakotoarison, Andolalao; Erens, Jesse; Ratsoavina, Fanomezana M.; Vences, Miguel

    2015-01-01

    This study summarises amphibian and reptile records from ad hoc surveys in a series of localities in the North-West of Madagascar, largely centred on the delta of the Betsiboka River. Eleven amphibian and approximately 32 reptile species were found, with taxonomic uncertainties remaining for some

  9. The pituitary-skin connection in amphibians. Reciprocal regulation of melanotrope cells and dermal melanocytes.

    Science.gov (United States)

    Vaudry, H; Chartrel, N; Desrues, L; Galas, L; Kikuyama, S; Mor, A; Nicolas, P; Tonon, M C

    1999-10-20

    In amphibians, alpha-MSH secreted by the pars intermedia of the pituitary plays a pivotal role in the process of skin color adaptation. Reciprocally, the skin of amphibians contains a number of regulatory peptides, some of which have been found to regulate the activity of pituitary melanotrope cells. In particular, the skin of certain species of amphibians harbours considerable amounts of thyrotropin-releasing hormone, a highly potent stimulator of alpha-MSH release. Recently, we have isolated and sequenced from the skin of the frog Phyllomedusa bicolor--a novel peptide named skin peptide tyrosine tyrosine (SPYY), which exhibits 94% similarity with PYY from the frog Rana ridibunda. For concentrations ranging from 5 x 10(-10) to 10(-7) M, SPYY induces a dose-related inhibition of alpha-MSH secretion. At a dose of 10(-7) M, SPYY totally abolished alpha-MSH release. These data strongly suggest the existence of a regulatory loop between the pars intermedia of the pituitary and the skin in amphibians.

  10. Reproduction, embryonic development, and maternal transfer of contaminants in the amphibian Gastrophryne carolinensis

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, W.A.; DuRant, S.E.; Staub, B.P.; Rowe, C.L.; Jackson, B.P. [Virginia Polytechnic Institute & State University, Blacksburg, VA (United States). Dept. of Fisheries & Wildlife Science

    2006-05-15

    Although many amphibian populations around the world are declining at alarming rates, the cause of most declines remains unknown. Environmental contamination is one of several factors implicated in declines and may have particularly important effects on sensitive developmental stages. We examined maternal transfer of contaminants in eastern narrow-mouth toads (Gastrophryne carolinensis) collected from a reference site and near a coal-burning power plant. Adult toads inhabiting the industrial area transferred significant quantities of selenium and strontium to their eggs, but Se concentrations were most notable (up to 100 {mu} g/g dry mass). Compared with the reference site, hatching success was reduced by 11% in clutches from the contaminated site. In surviving larvae, the frequency of developmental abnormalities and abnormal swimming was 55-58% higher in the contaminated site relative to the reference site. Craniofacial abnormalities were nearly an order of magnitude more prevalent in hatchlings from the contaminated site. When all developmental criteria were considered collectively, offspring from the contaminated site experienced 19% lower viability. Although there was no statistical relationship between the concentration of Se or Sr transferred to eggs and any measure of offspring viability, our study demonstrates that maternal transfer may be an important route of contaminant exposure in amphibians that has been overlooked.

  11. South African red data book - Reptiles and Amphibians

    CSIR Research Space (South Africa)

    Mclachlan, GR

    1978-02-01

    Full Text Available Data sheets are provided for 46 threatened South African reptiles and amphibians, two being endangered (leatherback turtle, geometric tortoise) ten vulnerable (loggerhead turtle, Nile crocodile, veld monitor, water monitor, giant girdled lizard...

  12. The economic efficiency of conservation measures for amphibians in organic farming--results from bio-economic modelling.

    Science.gov (United States)

    Schuler, Johannes; Sattler, Claudia; Helmecke, Angela; Zander, Peter; Uthes, Sandra; Bachinger, Johann; Stein-Bachinger, Karin

    2013-01-15

    This paper presents a whole farm bio-economic modelling approach for the assessment and optimisation of amphibian conservation conditions applied at the example of a large scale organic farm in North-Eastern Germany. The assessment focuses mainly on the habitat quality as affected by conservation measures such as through specific adapted crop production activities (CPA) and in-field buffer strips for the European tree frog (Hyla arborea), considering also interrelations with other amphibian species (i.e. common spadefoot toad (Pelobates fuscus), fire-bellied toad (Bombina bombina)). The aim of the approach is to understand, analyse and optimize the relationships between the ecological and economic performance of an organic farming system, based on the expectation that amphibians are differently impacted by different CPAs. The modelling system consists of a set of different sub-models that generate a farm model on the basis of environmentally evaluated CPAs. A crop-rotation sub-model provides a set of agronomically sustainable crop rotations that ensures overall sufficient nitrogen supply and controls weed, pest and disease infestations. An economic sub-model calculates the gross margins for each possible CPA including costs of inputs such as labour and machinery. The conservation effects of the CPAs are assessed with an ecological sub-model evaluates the potential negative or positive effect that each work step of a CPA has on amphibians. A mathematical programming sub-model calculates the optimal farm organization taking into account the limited factors of the farm (e.g. labour, land) as well as ecological improvements. In sequential model runs, the habitat quality is to be improved by the model, while the highest possible gross margin is still to be achieved. The results indicate that the model can be used to show the scope of action that a farmer has to improve habitat quality by reducing damage to amphibian population on its land during agricultural activities

  13. Can a Single Amphibian Species Be a Good Biodiversity Indicator?

    Directory of Open Access Journals (Sweden)

    David Sewell

    2009-11-01

    Full Text Available Although amphibians have been widely promoted as indicators of biodiversity and environmental change, rigorous tests are lacking. Here key indicator criteria are distilled from published papers, and a species that has been promoted as a bioindicator, the great crested newt, is tested against them. Although a link was established between the presence of great crested newts and aquatic plant diversity, this was not repeated with the diversity of macroinvertebrates. Equally, amphibians do not meet many of the published criteria of bioindicators. Our research suggests that a suite of indicators, rather than a single species, will usually be required.

  14. Toxicity of a glufosinate- and several glyphosate-based herbicides to juvenile amphibians from the Southern High Plains, USA.

    Science.gov (United States)

    Dinehart, Simon K; Smith, Loren M; McMurry, Scott T; Anderson, Todd A; Smith, Philip N; Haukos, David A

    2009-01-15

    Pesticide toxicity is often proposed as a contributing factor to the world-wide decline of amphibian populations. We assessed acute toxicity (48 h) of a glufosinate-based herbicide (Ignite 280 SL) and several glyphosate-based herbicide formulations (Roundup WeatherMAX, Roundup Weed and Grass Killer Super Concentrate, Roundup Weed and Grass Killer Ready-To-Use Plus on two species of amphibians housed on soil or moist paper towels. Survival of juvenile Great Plains toads (Bufo cognatus) and New Mexico spadefoots (Spea multiplicata) was reduced by exposure to Roundup Weed and Grass Killer Ready-To-Use Plus on both substrates. Great Plains toad survival was also reduced by exposure to Roundup Weed and Grass Killer Super Concentrate on paper towels. New Mexico spadefoot and Great Plains toad survival was not affected by exposure to the two agricultural herbicides (Roundup WeatherMAX and Ignite 280 SL) on either substrate, suggesting that these herbicides likely do not pose an immediate risk to these species under field conditions.

  15. Amphibians in the Environmental Park Chico Mendes, Rio Branco – Acre, Brazil

    Directory of Open Access Journals (Sweden)

    Nathocley Mendes Venâncio

    2016-02-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2016v29n1p85 Acre’s amphibian fauna, although poorly known, is regarded as one of the most diversified. This study aimed to inventory the amphibian fauna in the Environmental Park Chico Mendes, a 57 ha forest fragment, located 7 km far from downtown Rio Branco. The study was conducted between August 2008 and July 2010, by using a visual and auditory search methodology. All tracks and temporary forest pools in the park were inventoried, where the individuals visualized or those using vocalization were registered. A total of 51 taxa were found, distributed into the orders: Anura, with 50 species, and Caudata, with 1 species. Amphibians in the park showed seasonality in reproduction, where the rainiest months were those with the highest number of species in reproductive activity.

  16. Hurricane storm surge and amphibian communities in coastal wetlands of northwestern Florida

    Science.gov (United States)

    Gunzburger, M.S.; Hughes, W.B.; Barichivich, W.J.; Staiger, J.S.

    2010-01-01

    Isolated wetlands in the Southeastern United States are dynamic habitats subject to fluctuating environmental conditions. Wetlands located near marine environments are subject to alterations in water chemistry due to storm surge during hurricanes. The objective of our study was to evaluate the effect of storm surge overwash on wetland amphibian communities. Thirty-two wetlands in northwestern Florida were sampled over a 45-month period to assess amphibian species richness and water chemistry. During this study, seven wetlands were overwashed by storm surge from Hurricane Dennis which made landfall 10 July 2005 in the Florida panhandle. This event allowed us to evaluate the effect of storm surge overwash on water chemistry and amphibian communities of the wetlands. Specific conductance across all wetlands was low pre-storm (marine habitats are resistant to the effects of storm surge overwash. ?? 2010 Springer Science+Business Media B.V.

  17. Death in the clouds: ranavirus associated mortality in assemblage of cloud forest amphibians in Nicaragua

    NARCIS (Netherlands)

    Stark, T.; Laurijssens, C.; Weterings, M.J.A.; Spitzen-van der Sluis, A.; Martel, A.; Pasmans, F.

    2014-01-01

    Amphibian diseases are acknowledged as significant contributors to the decline and extinction of amphibian species. The main culprits currently considered are chytridiomycosis and Ranavirus. In Central America, highly endemic and geographical restricted terrestrial species may be at risk from these

  18. Mine spoil prairies expand critical habitat for endangered and threatened amphibian and reptile species

    Science.gov (United States)

    Lannoo, Michael J.; Kinney, Vanessa C.; Heemeyer, Jennifer L.; Engbrecht, Nathan J.; Gallant, Alisa L.; Klaver, Robert W.

    2009-01-01

    Coal extraction has been occurring in the Midwestern United States for over a century. Despite the pre-mining history of the landscape as woodlands, spent surface coalfields are often reclaimed to grasslands. We assessed amphibian and reptile species on a large tract of coal spoil prairie and found 13 species of amphibians (nine frog and four salamander species) and 19 species of reptiles (one lizard, five turtle, and 13 snake species). Two state-endangered and three state species of special concern were documented. The amphibian diversity at our study site was comparable to the diversity found at a large restored prairie situated 175 km north, within the historic prairie peninsula.

  19. Combined exposure to ambient UVB radiation and nitrite negatively affects survival of amphibian early life stages

    International Nuclear Information System (INIS)

    Macias, Guadalupe; Marco, Adolfo; Blaustein, Andrew R.

    2007-01-01

    Many aquatic species are sensitive to ambient levels of ultraviolet-B radiation (UVB) and chemical fertilizers. However, recent studies indicate that the interaction among multiple stressors acting simultaneously could be contributing to the population declines of some animal species. Therefore, we tested the potential synergistic effects between ambient levels of UVB and a contaminant, sodium nitrite in the larvae of two amphibian species, the common European toad Bufo bufo and the Iberian green frog Rana perezi. We studied R. perezi from both mountain and coastal populations to examine if populations of the same species varied in their response to stressors in different habitats. Both species were sensitive to the two stressors acting alone, but the interaction between the two stressors caused a multiplicative impact on tadpole survival. For B. bufo, the combination of UVB and nitrite was up to seven times more lethal than mortality for each stressor alone. In a coastal wetland, the combination of UVB and nitrite was four times more toxic for R. perezi than the sum of the effect on mortality for each stressor alone. One mg/L of nitrite killed half the population of R. perezi at Gredos Mountains at day 10 in the absence of UVB. In the presence of UVB, 50% of the tadpoles from the same experiment died at day 7. Similar toxic response were found for R. perezi in two highly contrasted environments suggesting this synergistic interaction can be a widespread phenomenon. The interaction of excess chemical fertilizers and manure with ambient UVB radiation could be contributing to the global decline of some amphibian species. We suggest that potential exposure to UVB radiation be accounted for when assessing water quality criteria regarding nitrite pollution

  20. Combined exposure to ambient UVB radiation and nitrite negatively affects survival of amphibian early life stages

    Energy Technology Data Exchange (ETDEWEB)

    Macias, Guadalupe [Donana Biological Station, CSIC, Spanish Council for Scientific Research. P.O. Box 1056, Sevilla 41013 (Spain); Marco, Adolfo [Donana Biological Station, CSIC, Spanish Council for Scientific Research. P.O. Box 1056, Sevilla 41013 (Spain)], E-mail: amarco@ebd.csic.es; Blaustein, Andrew R. [Department of Zoology, Oregon State University, Corvallis, Oregon, 97331 (United States)

    2007-10-15

    Many aquatic species are sensitive to ambient levels of ultraviolet-B radiation (UVB) and chemical fertilizers. However, recent studies indicate that the interaction among multiple stressors acting simultaneously could be contributing to the population declines of some animal species. Therefore, we tested the potential synergistic effects between ambient levels of UVB and a contaminant, sodium nitrite in the larvae of two amphibian species, the common European toad Bufo bufo and the Iberian green frog Rana perezi. We studied R. perezi from both mountain and coastal populations to examine if populations of the same species varied in their response to stressors in different habitats. Both species were sensitive to the two stressors acting alone, but the interaction between the two stressors caused a multiplicative impact on tadpole survival. For B. bufo, the combination of UVB and nitrite was up to seven times more lethal than mortality for each stressor alone. In a coastal wetland, the combination of UVB and nitrite was four times more toxic for R. perezi than the sum of the effect on mortality for each stressor alone. One mg/L of nitrite killed half the population of R. perezi at Gredos Mountains at day 10 in the absence of UVB. In the presence of UVB, 50% of the tadpoles from the same experiment died at day 7. Similar toxic response were found for R. perezi in two highly contrasted environments suggesting this synergistic interaction can be a widespread phenomenon. The interaction of excess chemical fertilizers and manure with ambient UVB radiation could be contributing to the global decline of some amphibian species. We suggest that potential exposure to UVB radiation be accounted for when assessing water quality criteria regarding nitrite pollution.

  1. Cerebral Hemodynamics in a Healthy Population Measured by Dynamic Susceptibility Contrast MR Imaging

    International Nuclear Information System (INIS)

    Helenius, J.; Soinne, L.; Tatlisumak, T.; Kaste, M.; Aronen, H.J.

    2003-01-01

    Purpose: To establish reference data and to study age-dependency for cerebral perfusion in various regions of the brain in a healthy population. Material and Methods: Eighty healthy subjects of both genders from 22 to 85 years of age were studied with spin echo echo-planar dynamic susceptibility contrast MR imaging (DSC MRI) at 1.5 T. Cerebral blood volume (CBV), cerebral blood flow (CBF), and contrast agent mean transit time (MTT) were calculated bilaterally for 20 distinct neuro anatomic structures. Results: In gray matter, the following values were found (mean ± SD): CBV (4.6 ± 1.0 ml/100 g), CBF (94.2 ± 23.0 ml/100 g/min), and MTT (3.0 ± 0.6 s), and in white matter: CBV (1.3 ± 0.4 ml/100 g), CBF (19.6 ± 5.8 ml/100 g/min), and MTT (4.3 ± 0.7 s). The perfusion parameters did not change with age, except for a tendency to an increase in gray matter MTT and CBV. Males exhibited higher MTT and CBV than females. No hemispheric difference was found in either gender. Conclusion: Cerebral hemodynamics can be assessed with DSC MRI. Age itself seems to have only a marginal effect on cerebral perfusion in healthy population

  2. Cerebral Hemodynamics in a Healthy Population Measured by Dynamic Susceptibility Contrast MR Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Helenius, J.; Soinne, L.; Tatlisumak, T.; Kaste, M. [Helsinki Univ. Central Hospital (Finland). Dept. of Neurology; Perkioe, J.; Salonen, O.; Savolainen, S. [Helsinki Univ. Central Hospital (Finland). Dept. of Radiology; Oestergaard, L. [Aarhus Univ. Hospital (Denmark). Dept. of Neuroradiology; Carano, R.A.D. [Synarc Inc., San Francisco, CA (United States); Aronen, H.J. [Helsinki Brain Research Center (Finland). Functional Brain Imaging Unit

    2003-09-01

    Purpose: To establish reference data and to study age-dependency for cerebral perfusion in various regions of the brain in a healthy population. Material and Methods: Eighty healthy subjects of both genders from 22 to 85 years of age were studied with spin echo echo-planar dynamic susceptibility contrast MR imaging (DSC MRI) at 1.5 T. Cerebral blood volume (CBV), cerebral blood flow (CBF), and contrast agent mean transit time (MTT) were calculated bilaterally for 20 distinct neuro anatomic structures. Results: In gray matter, the following values were found (mean {+-} SD): CBV (4.6 {+-} 1.0 ml/100 g), CBF (94.2 {+-} 23.0 ml/100 g/min), and MTT (3.0 {+-} 0.6 s), and in white matter: CBV (1.3 {+-} 0.4 ml/100 g), CBF (19.6 {+-} 5.8 ml/100 g/min), and MTT (4.3 {+-} 0.7 s). The perfusion parameters did not change with age, except for a tendency to an increase in gray matter MTT and CBV. Males exhibited higher MTT and CBV than females. No hemispheric difference was found in either gender. Conclusion: Cerebral hemodynamics can be assessed with DSC MRI. Age itself seems to have only a marginal effect on cerebral perfusion in healthy population.

  3. Amphibians from Liberia and the Gold Coast

    NARCIS (Netherlands)

    Parker, H.W.

    1936-01-01

    Thanks to the courtesy of Drs. Boschma and Brongersma the author has been privileged to examine a large series of West African amphibians from the collections of the Royal Museum of Natural History in Leiden. Of the comparatively easily accessible parts of Africa, Liberia is probably the least

  4. What's Slithering around on Your School Grounds? Transforming Student Awareness of Reptile & Amphibian Diversity

    Science.gov (United States)

    Tomasek, Terry M.; Matthews, Catherine E.; Hall, Jeff

    2005-01-01

    The protocols used in a research project on amphibian and reptile diversity at Cool Springs Environmental Education Center near New Bern, North Carolina is described. An increasing or stable number of amphibians and reptiles would indicate that the forest has a balance of invertebrates, leaf litter, moisture, pH, debris, burrows and habitat…

  5. Fight Fungi with Fungi: Antifungal Properties of the Amphibian Mycobiome

    Directory of Open Access Journals (Sweden)

    Patrick J. Kearns

    2017-12-01

    Full Text Available Emerging infectious diseases caused by fungal taxa are increasing and are placing a substantial burden on economies and ecosystems worldwide. Of the emerging fungal diseases, chytridomycosis caused by the fungus Batrachochytrium dendrobatidis (hereafter Bd is linked to global amphibian declines. Amphibians have innate immunity, as well as additional resistance through cutaneous microbial communities. Despite the targeting of bacteria as potential probiotics, the role of fungi in the protection against Bd infection in unknown. We used a four-part approach, including high-throughput sequencing of bacterial and fungal communities, cultivation of fungi, Bd challenge assays, and experimental additions of probiotic to Midwife Toads (Altyes obstetricans, to examine the overlapping roles of bacterial and fungal microbiota in pathogen defense in captive bred poison arrow frogs (Dendrobates sp.. Our results revealed that cutaneous fungal taxa differed from environmental microbiota across three species and a subspecies of Dendrobates spp. frogs. Cultivation of host-associated and environmental fungi realved numerous taxa with the ability to inhibit or facilitate the growth of Bd. The abundance of cutaneous fungi contributed more to Bd defense (~45% of the fungal community, than did bacteria (~10% and frog species harbored distinct inhibitory communities that were distinct from the environment. Further, we demonstrated that a fungal probiotic therapy did not induce an endocrine-immune reaction, in contrast to bacterial probiotics that stressed amphibian hosts and suppressed antimicrobial peptide responses, limiting their long-term colonization potential. Our results suggest that probiotic strategies against amphibian fungal pathogens should, in addition to bacterial probiotics, focus on host-associated and environmental fungi such as Penicillium and members of the families Chaetomiaceae and Lasiosphaeriaceae.

  6. Salmonella diversity associated with wild reptiles and amphibians in Spain.

    Science.gov (United States)

    Briones, Víctor; Téllez, Sonia; Goyache, Joaquín; Ballesteros, Cristina; del Pilar Lanzarot, María; Domínguez, Lucas; Fernández-Garayzábal, José F

    2004-08-01

    During the spring and summer of 2001, faeces from 166 wild reptiles (94 individuals) and amphibians (72 individuals) from 21 different species found in central Spain were examined for the presence of Salmonella. Thirty-nine reptiles (41.5%) yielded 48 Salmonella isolates, whereas all the amphibians examined were negative. Subspecies Salmonella enterica enterica (I) accounted for up to 50% of isolates. Fourteen isolates (29.2%) belonged to subspecies diarizonae (IIIb), six isolates (12.5%) to subspecies salamae (II), and four isolates (8.3%) to subspecies arizonae (IIIa). Twenty-seven different serotypes were identified. Serotypes Anatum (12.5%), Herzliya (8.3%), Abony, 18:l,v:z, 9,12:z29:1,5 and 38:z10:z53 (6.2%/each) were the most frequently isolated. A high percentage (39.6%) of isolates belonged to serotypes previously associated with environmental sources. Also, 37.5% of isolates belonged to serotypes which had been related to human cases of salmonellosis. From these data, it is concluded that wild reptiles, but apparently not amphibians, may represent an important reservoir of Salmonella in nature and have potential implications for public health.

  7. 19 CFR 12.26 - Importations of wild animals, fish, amphibians, reptiles, mollusks, and crustaceans; prohibited...

    Science.gov (United States)

    2010-04-01

    ..., reptiles, mollusks, and crustaceans; prohibited and endangered and threatened species; designated ports of..., Birds, and Insects § 12.26 Importations of wild animals, fish, amphibians, reptiles, mollusks, and... crustacea), amphibians, reptiles, or the offspring or eggs of any of the foregoing which the Secretary of...

  8. Dynamics of radionuclide accumulation at amphibians and reptiles in the Poles'e state radioecological reserve

    International Nuclear Information System (INIS)

    Novitskij, R.V.

    1998-01-01

    It was studied the peculiarity of the radionuclide intake to organism of amphibians and reptiles in the Poles'e radioecological reserve in 1997. The radioactive contamination level of investigated area was from 15 to 40 Ci/km 2 . It was measured 38 samples (26 for amphibians and 12 for reptiles) from points with background gamma-irradiation from 35 to 800 micro R/h. For the last eleven years of investigation it was revealed the total tendency to reduction of level of gamma-radioactive accumulation in 18,8-42,6 times for amphibians and in 2,8-52,5 times for reptiles

  9. Effects of pollution on freshwater fish and amphibians

    International Nuclear Information System (INIS)

    Pickering, Q.H.; Hunt, E.P.; Phipps, G.L.; Roush, T.H.; Smith, W.E.; Spehar, D.L.; Stephan, C.E.; Tanner, D.K.

    1983-01-01

    A literature review is presented dealing with studies on the effects of pollution on freshwater fish and amphibians. The pollutants studied included acid mine drainage, PCBs, cadmium, lead, naphthalene, plutonium, in addition to several studies dealing with pH effects

  10. Healthy eating habits among the population of Serbia: gender and age differences.

    Science.gov (United States)

    Jovičić, Ana Đ

    2015-03-01

    The purpose of the study is to examine healthy eating habits of the population of Serbia through three dimensions: knowledge, problems, and feelings as well as to determine whether there are any differences between genders and among different age-groups. The research instrument was an Eating Habits Questionnaire (EHQ) which consisted of 35 items. There were 382 respondents involved in the study. The reliability and factor structure of the questionnaire were verified by using factor analysis. The results of MANOVA showed that there is a significant difference in the habits concerning healthy eating between men and women [F (3,378)=4.26, p=0.006; Wilks' Lambda=0.97]. When the results for the dependent variables (knowledge, problems, and feelings) were considered separately, it was determined that there is no significant difference between men and women, which confirms the results of the t-test. The effect of age on the three dimensions of healthy eating habits was examined within three age-groups, by using ANOVA. The results showed that knowledge about healthy eating increases with age [F (2,379)=6.14, p=0.002] as well as positive feelings which occur as a result of healthy eating [F (2,379)=3.66, p=0.027]. Unlike ANOVA, MANOVA showed difference among the age-groups only when it came to the 'knowledge' variable. This study is important as it shows the current state of awareness on healthy eating habits in the researched populace and may be the basis for further research in this field in Serbia.

  11. Elevated Corticosterone Levels and Changes in Amphibian Behavior Are Associated with Batrachochytrium dendrobatidis (Bd Infection and Bd Lineage.

    Directory of Open Access Journals (Sweden)

    Caitlin R Gabor

    Full Text Available Few studies have examined the role hormones play in mediating clinical changes associated with infection by the parasite Batrachochytrium dendrobatidis (Bd. Glucocorticoid (GC hormones such as corticosteroids (CORT regulate homeostasis and likely play a key role in response to infection in amphibians. We explore the relationship between CORT release rates and Bd infection in tadpoles of the common midwife toad, Alytes obstetricians, using a non-invasive water-borne hormone collection method across seven populations. We further examined whether tadpoles of A. muletensis infected with a hypervirulent lineage of Bd, BdGPL, had greater CORT release rates than those infected with a hypovirulent lineage, BdCAPE. Finally, we examined the relationship between righting reflex and CORT release rates in infected metamorphic toads of A. obstetricans. We found an interaction between elevation and Bd infection status confirming that altitude is associated with the overall severity of infection. In tandem, increasing elevation was associated with increasing CORT release rates. Tadpoles infected with the hypervirulent BdGPL had significantly higher CORT release rates than tadpoles infected with BdCAPE showing that more aggressive infections lead to increased CORT release rates. Infected metamorphs with higher CORT levels had an impaired righting reflex, our defined experimental endpoint. These results provide evidence that CORT is associated with an amphibian's vulnerability to Bd infection, and that CORT is also affected by the aggressiveness of infection by Bd. Together these results indicate that CORT is a viable biomarker of amphibian stress.

  12. Association between systemic inflammation and serum prostate-specific antigen in a healthy Korean population

    Science.gov (United States)

    Yun, Jonghyun; Lee, Hyunyoung; Yang, Wonjae

    2017-01-01

    Objective Serum prostate-specific antigen (PSA) may be elevated in healthy men with systemic inflammation. We aimed to investigate the association between systemic inflammation markers and serum PSA in a healthy Korean population. Material and methods A cohort of 20,151 healthy native Korean men without prostate disease between the ages of 40 and 65 years who underwent medical checkups were studied from January 2007 to December 2013. Serum total PSA and serum C-reactive protein concentrations, neutrophil, lymphocyte, and platelet counts were determined. The neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) were calculated. We checked the correlation between systemic inflammation markers and PSA. Results Data obtained from 18,800 healthy men were analyzed. The mean age of the study subjects was 50.72±7.62 years and the mean NLR was 1.764±0.804. Correlation analysis after adjustment for age and body mass index (BMI) revealed that neutrophil count (coefficient = 0.028, p value <0.001), and NLR (coefficient = 0.027, p value <0.001) correlated with PSA. Multivariate analysis using the full model revealed that age, neutrophil count and NLR were positively correlated with PSA (p<0.001, 0.001, and 0.043 respectively). Multivariate analysis using a stepwise model revealed that age, neutrophil count and NLR were positively correlated with PSA (p<0.001, 0.001, and 0.040, respectively) and BMI was negatively correlated with PSA (p<0.001). Conclusion Systemic inflammation markers are useful with a serum PSA in a healthy Korean population. NLR in particular is significantly associated with serum PSA. PMID:28861299

  13. SCREENING FOR GENETIC CHANGES AND CODON 129 POLYMORPHISM IN PRNP GENE IN HEALTHY SLOVENIAN POPULATION AND SPORADIC CASES OF CREUTZFELDT-JAKOB DISEASE

    Directory of Open Access Journals (Sweden)

    Sava Smerkolj

    2004-11-01

    Full Text Available Background. Prion protein has an important role in development of prion diseases, fatal neurodegenerative disorders. As the codon 129 genotype of the prion protein gene (PRNP is a known susceptibility factor for the diseases, we wanted to determine its distribution in healthy Slovenian population and also in cases of sporadic Creutzfeldt-Jakob disease (sCJD. Furthermore, we wanted to screen the whole gene in order to establish the presence of genetic changes.Methods. We screened 350 DNA samples of healthy blood donors and 12 DNA samples of patients deceased of sCJD. After the amplification and conformation analysis had been done, the gene was sequenced using an automatic sequencer.Results. Methionine homozygotes comprised 46.8% of healthy population, valine homozygotes 12.1% and heterozygotes 41.1%; out of 12 sCJD patients 10 were methionine homozygotes (83.3%, 1 was valine homozygote (8.3% and 1 was heterozygote (8.3%.Found SNPs were combination of codon 76 change (228C > T and codon 84 change (252T > C in a single sample of healthy population, combination of codon 68 change (204T > C and codon 76 change (228C > T in two samples of healthy population and codon 117 change (351A > G in a healthy population sample and in a valine homozygote patient.Conclusions. In comparison to the pooled Caucasian population is genotype M/M frequency slightly increased on account of decreased genotype M/V frequency in healthy Slovenian population, suggesting a little higher risk for acquiring a new variant of CJD (vCJD, because up to date all confirmed vCJD cases except one heterozygote were methionine homozygotes. Codon 129 genotype distribution in sCJD can be described as disease-specific. The absence of pathogenic mutations in sCJD patients confirms the non-familial, sporadic disease form.

  14. Sampling methods for terrestrial amphibians and reptiles.

    Science.gov (United States)

    Paul Stephen Corn; R. Bruce. Bury

    1990-01-01

    Methods described for sampling amphibians and reptiles in Douglas-fir forests in the Pacific Northwest include pitfall trapping, time-constrained collecting, and surveys of coarse woody debris. The herpetofauna of this region differ in breeding and nonbreeding habitats and vagility, so that no single technique is sufficient for a community study. A combination of...

  15. Biogeography of amphibians and reptiles in Arizona

    Science.gov (United States)

    Eric W. Stitt; Theresa M. Mau-Crimmins; Don E. Swann

    2005-01-01

    We examined patterns of species richness for amphibians and reptiles in Arizona and evaluated patterns in species distribution between ecoregions based on species range size. In Arizona, the Sonoran Desert has the highest herpetofauna diversity, and the southern ecoregions are more similar than other regions. There appear to be distinct low- and mid-elevational...

  16. Digestive Phenotypic Flexibility in Post-Metamorphic Amphibians: Studies on a Model Organism

    Directory of Open Access Journals (Sweden)

    DANIEL E NAYA

    2004-01-01

    Full Text Available Studies of phenotypic flexibility are central to the understanding of evolutionary and comparative physiology. Research conducted on many vertebrate species has shown that the digestive system is highly responsive and sensitive to environmental cues. However, amphibians, which are a standard and classic model organism for the study of many physiological processes, have been poorly considered in the study of ecological consequences on digestive flexibility. Here we review and analyze the current information on this topic for amphibians. We identify three major bodies of empirical evidence: a seasonal changes in gut development, b lack of dietary modulation of gut attributes in adult individuals, c a relationship between feeding habits and the magnitude of digestive performance regulation. Once the natural history characteristics of the species under study are taken into account, all the evidence is in full agreement with the predictions of digestive theory. We propose that evolutionary and comparative physiology could benefit greatly from the study of phenotypic flexibility in amphibians

  17. Forest Fragments Surrounded by Sugar Cane Are More Inhospitable to Terrestrial Amphibian Abundance Than Fragments Surrounded by Pasture

    Directory of Open Access Journals (Sweden)

    Paula Eveline Ribeiro D’Anunciação

    2013-01-01

    Full Text Available In recent years, there has been increasing interest in matrix-type influence on forest fragments. Terrestrial amphibians are good bioindicators for this kind of research because of low vagility and high philopatry. This study compared richness, abundance, and species composition of terrestrial amphibians through pitfall traps in two sets of semideciduous seasonal forest fragments in southeastern Brazil, according to the predominant surrounding matrix (sugar cane and pasture. There were no differences in richness, but fragments surrounded by sugar cane had the lowest abundance of amphibians, whereas fragments surrounded by pastures had greater abundance. The most abundant species, Rhinella ornata, showed no biometric differences between fragment groups but like many other amphibians sampled showed very low numbers of individuals in fragments dominated by sugar cane fields. Our data indicate that the sugar cane matrix negatively influences the community of amphibians present in fragments surrounded by this type of land use.

  18. [Investigation of the situation of vaginal microflora in healthy women population].

    Science.gov (United States)

    Ji, Fang; Zhang, Ning; Di, Wen; Liao, Qin-ping; Wang, Wen; Zhao, Xiao-ming; Sun, Yun; Liu, Zhao-hui

    2009-01-01

    To assess the distribution of vaginal microflora in healthy women and investigate their cognition of lower reproductive tract infection-related knowledge as well as personal hygiene habits and character of behavior in seeking medical treatment. Total of 1660 healthy women who had physical check-ups at the Medical Center of Renji Hospital were selected and received gynecologic examination, as well as routine examination, pH examination and bacterial culture of the vaginal discharge. In addition, 860 of them were randomly selected for questionnaire survey, in which reproductive tract infection -related knowledge and personal hygiene habits as well as behavior in seeking medical treatment were involved. Among the 1660 censused women, vaginal average pH was 4. 16 +/- 0.21. The positive rate of Candida in vaginal discharge routine examination was 3.86% (64/1660), which was lower than that in aerobes culture 7.71% (128/1660). Candida albicans was the most populous species 78.9% (101/128), followed by 7.8% (10/128) and 7.0% (9/128) for the Candida glabrata and Candida krusei respectively. The most populous species of vaginal microflora were hemolytic streptococcus A (63.80%, 1059/1660), Staphylococcus epidermidis (14.28%, 237/1660), and Enterococcus faecalis (D) group (11.44%, 190/1660). The questionnaire survey showed that 88.4% (760/860) of 860 women took active treatment when feeling unwell, 92.1% (792/860) of them had good hygiene practices, and only 21.2% (182/860) had the habit of vaginal douching. In addition, 50.0% (430/860) of them had the desire to obtain reproductive health knowledge through out-patient consultation. Vulvovaginal Candida disease ranks the first in all types of vaginitis, among which, Candida albicans is the most populous species followed by the Candida glabrata and Candida krusei. Hemolytic streptococcus A and Staphylococcus epidermidis are the most common species of vaginal microflora in healthy women. The censused women have high awareness of

  19. Evaluating the links between climate, disease spread, and amphibian declines.

    Science.gov (United States)

    Rohr, Jason R; Raffel, Thomas R; Romansic, John M; McCallum, Hamish; Hudson, Peter J

    2008-11-11

    Human alteration of the environment has arguably propelled the Earth into its sixth mass extinction event and amphibians, the most threatened of all vertebrate taxa, are at the forefront. Many of the worldwide amphibian declines have been caused by the chytrid fungus, Batrachochytrium dendrobatidis (Bd), and two contrasting hypotheses have been proposed to explain these declines. Positive correlations between global warming and Bd-related declines sparked the chytrid-thermal-optimum hypothesis, which proposes that global warming increased cloud cover in warm years that drove the convergence of daytime and nighttime temperatures toward the thermal optimum for Bd growth. In contrast, the spatiotemporal-spread hypothesis states that Bd-related declines are caused by the introduction and spread of Bd, independent of climate change. We provide a rigorous test of these hypotheses by evaluating (i) whether cloud cover, temperature convergence, and predicted temperature-dependent Bd growth are significant positive predictors of amphibian extinctions in the genus Atelopus and (ii) whether spatial structure in the timing of these extinctions can be detected without making assumptions about the location, timing, or number of Bd emergences. We show that there is spatial structure to the timing of Atelopus spp. extinctions but that the cause of this structure remains equivocal, emphasizing the need for further molecular characterization of Bd. We also show that the reported positive multi-decade correlation between Atelopus spp. extinctions and mean tropical air temperature in the previous year is indeed robust, but the evidence that it is causal is weak because numerous other variables, including regional banana and beer production, were better predictors of these extinctions. Finally, almost all of our findings were opposite to the predictions of the chytrid-thermal-optimum hypothesis. Although climate change is likely to play an important role in worldwide amphibian declines

  20. Host Ecology Rather Than Host Phylogeny Drives Amphibian Skin Microbial Community Structure in the Biodiversity Hotspot of Madagascar

    OpenAIRE

    Bletz, Molly C.; Archer, Holly; Harris, Reid N.; McKenzie, Valerie J.; Rabemananjara, Falitiana C. E.; Rakotoarison, Andolalao; Vences, Miguel

    2017-01-01

    Host-associated microbiotas of vertebrates are diverse and complex communities that contribute to host health. In particular, for amphibians, cutaneous microbial communities likely play a significant role in pathogen defense; however, our ecological understanding of these communities is still in its infancy. Here, we take advantage of the fully endemic and locally species-rich amphibian fauna of Madagascar to investigate the factors structuring amphibian skin microbiota on a large scale. Usin...

  1. Cadmium pollution and amphibians--Studies in tadpoles of Rana limnocharis.

    Science.gov (United States)

    Patar, Arabinda; Giri, Anirudha; Boro, Freeman; Bhuyan, Krishna; Singha, Utsab; Giri, Sarbani

    2016-02-01

    Cadmium is released into the environment in increasing amounts from different natural and anthropogenic activities contaminating the aquatic habitats. Amphibian tadpoles develop in water and hence are likely to be adversely affected by cadmium present in the aquatic environment. We have studied the toxic and genotoxic effects of CdCl2 on the tadpoles of Rana limnocharis. CdCl2 in the concentration range between 0.1 and 0.4 mg/L induced significant mortality in R. limnocharis tadpoles in a dose and time dependent manner. The 10-day LC50 which has more ecological relevance was far less than the 24-h LC50. Tadpoles exposed to CdCl2 metamorphosed at an early age possibly as a survival strategy to move out of the stressful environment. The body weight of the CdCl2 exposed animals at metamorphosis was lower compared to the control individuals which may affect survival and reproductive fitness in adult life. Besides, the average body length of the metamorphosed individuals in the CdCl2 exposed group was higher than the control group. CdCl2 was found to be genotoxic in micronucleus test and comet assay. The ambient concentration of Cd could reach up to 60 μg/L or more. Exposure to 18.5 μg/L of CdCl2 (1% of 24-h LC50) induced significant increase in DNA strand breaks as compared to the control. The present findings demonstrate that presence of cadmium in the aquatic environment can significantly alter the life history traits and cause DNA damage in amphibians and hence, could contribute towards their population decline. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Predictors of breeding site occupancy by amphibians in montane landscapes

    Science.gov (United States)

    Groff, Luke A.; Loftin, Cynthia S.; Calhoun, Aram J.K.

    2017-01-01

    Ecological relationships and processes vary across species’ geographic distributions, life stages and spatial, and temporal scales. Montane landscapes are characterized by low wetland densities, rugged topographies, and cold climates. Consequently, aquatic-dependent and low-vagility ectothermic species (e.g., pool-breeding amphibians) may exhibit unique ecological associations in montane landscapes. We evaluated the relative importance of breeding- and landscape-scale features associated with spotted salamander (Ambystoma maculatum) and wood frog (Lithobates sylvaticus) wetland occupancy in Maine's Upper Montane-Alpine Zone ecoregion, and we determined whether models performed better when the inclusive landscape-scale covariates were estimated with topography-weighted or circular buffers. We surveyed 135 potential breeding sites during May 2013–June 2014 and evaluated environmental relationships with multi-season implicit dynamics occupancy models. Breeding site occupancy by both species was influenced solely by breeding-scale habitat features. Spotted salamander occupancy probabilities increased with previous or current beaver (Castor canadensis) presence, and models generally were better supported when the inclusive landscape-scale covariates were estimated with topography-weighted rather than circular buffers. Wood frog occupancy probabilities increased with site area and percent shallows, but neither buffer type was better supported than the other. Model rank order and support varied between buffer types, but model inferences did not. Our results suggest pool-breeding amphibian conservation in montane Maine include measures to maintain beaver populations and large wetlands with proportionally large areas of shallows ≤1-m deep. Inconsistencies between our study and previous studies substantiate the value of region-specific research for augmenting species’ conservation management plans and suggest the application of out-of-region inferences may promote

  3. Bent's Old Fort: Amphibians and Reptiles

    Science.gov (United States)

    Muths, E.

    2008-01-01

    Bent's Old Fort National Historic Site sits along the Arkansas River in the semi-desert prairie of southeastern Colorado. The USGS provided assistance in designing surveys to assess the variety of herpetofauna (amphibians and reptiles) resident at this site. This brochure is the results of those efforts and provides visitors with information on what frogs, toads, snakes and salamanders might be seen and heard at Bent's Old Fort.

  4. Evidence for the persistence of food web structure after amphibian extirpation in a Neotropical stream.

    Science.gov (United States)

    Barnum, Thomas R; Drake, John M; Colón-Gaud, Checo; Rugenski, Amanda T; Frauendorf, Therese C; Connelly, Scott; Kilham, Susan S; Whiles, Matt R; Lips, Karen R; Pringle, Catherine M

    2015-08-01

    Species losses are predicted to simplify food web structure, and disease-driven amphibian declines in Central America offer an opportunity to test this prediction. Assessment of insect community composition, combined with gut content analyses, was used to generate periphyton-insect food webs for a Panamanian stream, both pre- and post-amphibian decline. We then used network analysis to assess the effects of amphibian declines on food web structure. Although 48% of consumer taxa, including many insect taxa, were lost between pre- and post-amphibian decline sampling dates, connectance declined by less than 3%. We then quantified the resilience of food web structure by calculating the number of expected cascading extirpations from the loss of tadpoles. This analysis showed the expected effects of species loss on connectance and linkage density to be more than 60% and 40%, respectively, than were actually observed. Instead, new trophic linkages in the post-decline food web reorganized the food web topology, changing the identity of "hub" taxa, and consequently reducing the effects of amphibian declines on many food web attributes. Resilience of food web attributes was driven by a combination of changes in consumer diets, particularly those of insect predators, as well as the appearance of generalist insect consumers, suggesting that food web structure is maintained by factors independent of the original trophic linkages.

  5. Book review: Reptiles and amphibians: Self-assessment color review

    Science.gov (United States)

    Green, David E.

    2017-01-01

    No abstract available.Book information: Reptiles and Amphibians: Self-Assessment Color Review. 2nd Edition. By Fredric L. Frye. CRC Press, Taylor and Francis Group, Boca Raton, Florida USA. 2015. 252 pp. ISBN 9781482257601.

  6. Parasitic infections of amphibians in the Pendjari Biosphere ...

    African Journals Online (AJOL)

    Parasitic infections of amphibians in the Pendjari Biosphere Reserve, Benin. ... Results obtained show the possible influence of land-use pattern on parasite distribution. For example, the ... Furthermore, this infection pattern may be indicative of an immunosuppressive effect of pesticides on the frogs of the Agricultural Zone.

  7. Population dynamics of the critically endangered toad Atelopus cruciger and the fungal disease chytridiomycosis

    Science.gov (United States)

    Señaris, Celsa; García, Carmen Zulay

    2017-01-01

    Harlequin toads (Atelopus) are among the most severely impacted amphibians by the emergence of chytridiomycosis, a fungal disease caused by the pathogen Batrachochytrium dendrobatidis (Bd). Many species disappeared while others suffered drastic contractions of their geographic distribution to lower altitudes. A diminished virulence of Bd in warm habitats was proposed to explain the survival of lowland populations of harlequin toads (i.e. thermal refuge hypothesis). To understand the mechanisms that allow some populations to reach an endemic equilibrium with this pathogen, we estimated demographic and epidemiological parameters at one remnant population of Atelopus cruciger in Venezuela using mark-recapture data from 2007–2013. We demonstrated that Bd is highly virulent for A. cruciger, increasing the odds of dying of infected adults four times in relation to uninfected ones and reducing the life expectancy of reproductive toads to a few weeks. Despite an estimated annual loss of 18% of the reproductive population due to Bd-induced mortality, this population has persisted in an endemic equilibrium for the last decade through the large recruitment of healthy adults every year. Given the high vulnerability of harlequin toads to Bd in lowland populations, thermal refuges need to be redefined as habitats of reduced transmission rather than attenuated virulence. PMID:28570689

  8. Linking global climate and temperature variability to widespread amphibian declines putatively caused by disease.

    Science.gov (United States)

    Rohr, Jason R; Raffel, Thomas R

    2010-05-04

    The role of global climate change in the decline of biodiversity and the emergence of infectious diseases remains controversial, and the effect of climatic variability, in particular, has largely been ignored. For instance, it was recently revealed that the proposed link between climate change and widespread amphibian declines, putatively caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd), was tenuous because it was based on a temporally confounded correlation. Here we provide temporally unconfounded evidence that global El Niño climatic events drive widespread amphibian losses in genus Atelopus via increased regional temperature variability, which can reduce amphibian defenses against pathogens. Of 26 climate variables tested, only factors associated with temperature variability could account for the spatiotemporal patterns of declines thought to be associated with Bd. Climatic predictors of declines became significant only after controlling for a pattern consistent with epidemic spread (by temporally detrending the data). This presumed spread accounted for 59% of the temporal variation in amphibian losses, whereas El Niño accounted for 59% of the remaining variation. Hence, we could account for 83% of the variation in declines with these two variables alone. Given that global climate change seems to increase temperature variability, extreme climatic events, and the strength of Central Pacific El Niño episodes, climate change might exacerbate worldwide enigmatic declines of amphibians, presumably by increasing susceptibility to disease. These results suggest that changes to temperature variability associated with climate change might be as significant to biodiversity losses and disease emergence as changes to mean temperature.

  9. Toxicity of road salt to Nova Scotia amphibians.

    Science.gov (United States)

    Collins, Sara J; Russell, Ronald W

    2009-01-01

    The deposition of chemical pollutants into roadside wetlands from runoff is a current environmental concern. In northern latitudes, a major pollutant in runoff water is salt (NaCl), used as de-icing agents. In this study, 26 roadside ponds were surveyed for amphibian species richness and chloride concentration. Acute toxicity tests (LC(50)) were performed on five locally common amphibian species using a range of environmentally significant NaCl concentrations. Field surveys indicated that spotted salamanders (Ambystoma maculatum) and wood frogs (Rana sylvatica) did not occupy high chloride ponds. American toads (Bufo americanus) showed no pond preference based on chloride concentration. Acute toxicity tests showed spotted salamanders and wood frogs were most sensitive to chloride, and American toads were the least. Spring peepers (Pseudacris crucifer) and green frogs (Rana clamitans) showed intermediate sensitivities. We concluded that chloride concentrations in ponds due to application of de-icing salts, influenced community structure by excluding salt intolerant species.

  10. Ecological Risk Assessment of Perchlorate in Avian Species, Rodents, Amphibians and Fish: FY2003

    Science.gov (United States)

    2005-10-01

    Ecological Receptors at the Longhorn Army Ammunition Plant (LHAAP), Karnack, TX. Ecotoxicology , 10: 305-313. Smith JN, Pan X, Gentles, BA, Smith...Page 32 of 225 Hayes, TB. 2000. Endocrine disruption in amphibians. In Sparling DW, Linder G, Bishop C, eds. Ecotoxicology of Amphibians and... macrophytes and was programmed in Matlab using difference equations. To simulate and predict the uptake and transport of explosives in various

  11. Allele and Genotype Distributions of DNA Repair Gene Polymorphisms in South Indian Healthy Population

    Directory of Open Access Journals (Sweden)

    Katiboina Srinivasa Rao

    2014-01-01

    Full Text Available Various DNA repair pathways protect the structural and chemical integrity of the human genome from environmental and endogenous threats. Polymorphisms of genes encoding the proteins involved in DNA repair have been found to be associated with cancer risk and chemotherapeutic response. In this study, we aim to establish the normative frequencies of DNA repair genes in South Indian healthy population and compare with HapMap populations. Genotyping was done on 128 healthy volunteers from South India, and the allele and genotype distributions were established. The minor allele frequency of Xeroderma pigmentosum group A ( XPA G23A, Excision repair cross-complementing 2 ( ERCC2 /Xeroderma pigmentosum group D ( XPD Lys751Gln, Xeroderma pigmentosum group G ( XPG His46His, XPG Asp1104His, and X-ray repair cross-complementing group 1 ( XRCC1 Arg399Gln polymorphisms were 49.2%, 36.3%, 48.0%, 23.0%, and 34.0% respectively. Ethnic variations were observed in the frequency distribution of these polymorphisms between the South Indians and other HapMap populations. The present work forms the groundwork for cancer association studies and biomarker identification for treatment response and prognosis.

  12. Skin swabs with FTA® cards as a dry storage source for amphibian DNA

    OpenAIRE

    Ward, A; Hide, G; Jehle, R

    2018-01-01

    Amphibians are the most endangered group of vertebrates, and conservation measures increasingly rely on information drawn from genetic markers. The present study explores skin swabs with Whatman FTA® cards as a method to retrieve PCR-amplifiable amphibian DNA. Swabs from ten adult great crested newts (Triturus cristatus) were used to compare FTA® card-based protocols with tissue sampling based on toe clips. PCR success rates were measured for seven microsatellite markers and one mtDNA marker ...

  13. Amphibian diversity and threatened species in a severely transformed neotropical region in Mexico.

    Science.gov (United States)

    Meza-Parral, Yocoyani; Pineda, Eduardo

    2015-01-01

    Many regions around the world concentrate a large number of highly endangered species that have very restricted distributions. The mountainous region of central Veracruz, Mexico, is considered a priority area for amphibian conservation because of its high level of endemism and the number of threatened species. The original tropical montane cloud forest in the region has been dramatically reduced and fragmented and is now mainly confined to ravines and hillsides. We evaluated the current situation of amphibian diversity in the cloud forest fragments of this region by analyzing species richness and abundance, comparing assemblage structure and species composition, examining the distribution and abundance of threatened species, and identifying the local and landscape variables associated with the observed amphibian diversity. From June to October 2012 we sampled ten forest fragments, investing 944 person-hours of sampling effort. A total of 895 amphibians belonging to 16 species were recorded. Notable differences in species richness, abundance, and assemblage structure between forest fragments were observed. Species composition between pairs of fragments differed by an average of 53%, with the majority (58%) resulting from species replacement and the rest (42%) explained by differences in species richness. Half of the species detected are under threat of extinction according to the International Union for Conservation of Nature, and although their distribution and abundance varied markedly, there were also ubiquitous and abundant species, along with rare species of restricted distribution. The evident heterogeneity of the ten study sites indicates that to conserve amphibians in a mountainous region such as this one it is necessary to protect groups of fragments which represent the variability of the system. Both individually and together cloud forest fragments are very important to conservation because each remnant is inhabited by several threatened species, some of

  14. Cell size is positively correlated between different tissues in passerine birds and amphibians, but not necessarily in mammals

    OpenAIRE

    Kozłowski, J.; Czarnołęski, M.; François-Krassowska, A.; Maciak, S.; Pis, T.

    2010-01-01

    We examined cell size correlations between tissues, and cell size to body mass relationships in passerine birds, amphibians and mammals. The size correlated highly between all cell types in birds and amphibians; mammalian tissues clustered by size correlation in three tissue groups. Erythrocyte size correlated well with the volume of other cell types in birds and amphibians, but poorly in mammals. In birds, body mass correlated positively with the size of all cell types including erythrocytes...

  15. Effects of atrazine on embryos, larvae, and adults of anuran amphibians.

    Science.gov (United States)

    Allran, J W; Karasov, W H

    2001-04-01

    We examined the effects of atrazine (0-20 mg/L) on embryos, larvae, and adult anuran amphibian species in the laboratory. Atrazine treatments did not affect hatchability of embryos or 96-h posthatch mortality of larvae of Rana pipiens, Rana sylvatica, or Bufo americanus. Furthermore, atrazine had no effect on swimming speed (measured for R. pipiens only). However, there was a dose-dependent increase in deformed larvae of all three species with increasing atrazine concentration. In adult R. pipiens, atrazine increased buccal and thoracic ventilation, indicating respiratory distress. However, because atrazine had no affect on hemoglobin, this respiratory distress was probably not indicative of reduced oxygen-carrying capacity of the blood. Frogs exposed to the highest atrazine concentration stopped eating immediately after treatment began and did not eat during the 14-d experiment. However, no decreases in mass were measured even for frogs that were not eating, probably because of compensatory fluid gain from edema. Atrazine concentrations found to be deleterious to amphibian embryos and adults are considerably higher than concentrations currently found in surface waters in North America. Therefore, direct toxicity of atrazine is probably not a significant factor in recent amphibian declines.

  16. Using Reptile and Amphibian Activities in the Classroom

    Science.gov (United States)

    Tomasek, Terry; Matthews, Catherine E.

    2008-01-01

    Reptiles and amphibians are a diverse and interesting group of organisms. The four activities described in this article take students' curiosity into the realm of scientific understanding. The activities involve the concepts of species identification; animal adaptations, communication, and habitat; and conservation. (Contains 1 table and 2…

  17. Pesticides and Population Declines of California Alpine Frogs

    Science.gov (United States)

    Airborne pesticides from the Central Valley of California have been implicated as a cause for population declines of several amphibian species, with the strongest evidence for the mountain yellow-legged frog complex (Rana muscosa and R. sierrae) in the Sierra Nevada. We measured ...

  18. Lung collapse among aquatic reptiles and amphibians during long-term diving.

    Science.gov (United States)

    Ultsch, Gordon R; Brainerd, Elizabeth L; Jackson, Donald C

    2004-09-01

    Numerous aquatic reptiles and amphibians that typically breathe both air and water can remain fully aerobic in normoxic (aerated) water by taking up oxygen from the water via extrapulmonary avenues. Nevertheless, if air access is available, these animals do breathe air, however infrequently. We suggest that such air breathing does not serve an immediate gas exchange function under these conditions, nor is it necessarily related to buoyancy requirements, but serves to keep lungs inflated that would otherwise collapse during prolonged submergence. We also suggest that lung deflation is routine in hibernating aquatic reptiles and amphibians in the northern portions of their ranges, where ice cover prevents surfacing for extended periods.

  19. Phylogeny, life history, and ecology contribute to differences in amphibian susceptibility to ranaviruses.

    Science.gov (United States)

    Hoverman, Jason T; Gray, Matthew J; Haislip, Nathan A; Miller, Debra L

    2011-09-01

    Research that identifies the potential host range of generalist pathogens as well as variation in host susceptibility is critical for understanding and predicting the dynamics of infectious diseases within ecological communities. Ranaviruses have been linked to amphibian die-off events worldwide with the greatest number of reported mortality events occurring in the United States. While reports of ranavirus-associated mortality events continue to accumulate, few data exist comparing the relative susceptibility of different species. Using a series of laboratory exposure experiments and comparative phylogenetics, we compared the susceptibilities of 19 amphibian species from two salamander families and five anurans families for two ranavirus isolates: frog virus 3 (FV3) and an FV3-like isolate from an American bullfrog culture facility. We discovered that ranaviruses were capable of infecting 17 of the 19 larval amphibian species tested with mortality ranging from 0 to 100%. Phylogenetic comparative methods demonstrated that species within the anuran family Ranidae were generally more susceptible to ranavirus infection compared to species from the other five families. We also found that susceptibility to infection was associated with species that breed in semi-permanent ponds, develop rapidly as larvae, and have limited range sizes. Collectively, these results suggest that phylogeny, life history characteristics, and habitat associations of amphibians have the potential to impact susceptibility to ranaviruses.

  20. Climatic change and wetland desiccation cause amphibian decline in Yellowstone National Park.

    Science.gov (United States)

    McMenamin, Sarah K; Hadly, Elizabeth A; Wright, Christopher K

    2008-11-04

    Amphibians are a bellwether for environmental degradation, even in natural ecosystems such as Yellowstone National Park in the western United States, where species have been actively protected longer than anywhere else on Earth. We document that recent climatic warming and resultant wetland desiccation are causing severe declines in 4 once-common amphibian species native to Yellowstone. Climate monitoring over 6 decades, remote sensing, and repeated surveys of 49 ponds indicate that decreasing annual precipitation and increasing temperatures during the warmest months of the year have significantly altered the landscape and the local biological communities. Drought is now more common and more severe than at any time in the past century. Compared with 16 years ago, the number of permanently dry ponds in northern Yellowstone has increased 4-fold. Of the ponds that remain, the proportion supporting amphibians has declined significantly, as has the number of species found in each location. Our results indicate that climatic warming already has disrupted one of the best-protected ecosystems on our planet and that current assessments of species' vulnerability do not adequately consider such impacts.

  1. Plasticity and genetic adaptation mediate amphibian and reptile responses to climate change

    Science.gov (United States)

    Urban, Mark C; Richardson, Jonathan L; Freidenfelds, Nicole A

    2014-01-01

    Phenotypic plasticity and genetic adaptation are predicted to mitigate some of the negative biotic consequences of climate change. Here, we evaluate evidence for plastic and evolutionary responses to climate variation in amphibians and reptiles via a literature review and meta-analysis. We included studies that either document phenotypic changes through time or space. Plasticity had a clear and ubiquitous role in promoting phenotypic changes in response to climate variation. For adaptive evolution, we found no direct evidence for evolution of amphibians or reptiles in response to climate change over time. However, we found many studies that documented adaptive responses to climate along spatial gradients. Plasticity provided a mixture of adaptive and maladaptive responses to climate change, highlighting that plasticity frequently, but not always, could ameliorate climate change. Based on our review, we advocate for more experiments that survey genetic changes through time in response to climate change. Overall, plastic and genetic variation in amphibians and reptiles could buffer some of the formidable threats from climate change, but large uncertainties remain owing to limited data. PMID:24454550

  2. Streamside zone width and amphibian and reptile abundance

    Science.gov (United States)

    D. Craig Rudolph; James G. Dickson

    1990-01-01

    Many natural pine-hardwood stands in the southeastern United States are being converted to pine plantations with short rotations. This forest conversion alters vertebrate communities, particularly amphibians and reptiles (Bennett et al., 1980; Rakowitz, 1983). One practice in stand conversion to accommodate vertebrate species is the retention of strips of unharvested,...

  3. Engineering a future for amphibians under climate change

    Science.gov (United States)

    Luke P. Shoo; Deanna H. Olson; Sarah K. McMenamin; Kris A. Murray; Monique VanSluys; Maureen A. Donnelly; Danial Stratford; Juhani Terhivuo; Andres Merino-Viteri; Sarah M. Herbert; Phillip J. Bishop; Paul Stephen Corn; Liz Dovey; Richard A. Griffiths; Katrin Lowe; Michael Mahony; Hamish McCallum; Jonathan D. Shuker; Clay Simpkins; Lee F. Skerratt; Stephen E. Williams; Jean-Marc Hero

    2011-01-01

    Altered global climates in the 21st century pose serious threats for biological systems and practical actions are needed to mount a response for species at risk. We identify management actions from across the world and from diverse disciplines that are applicable to minimizing loss of amphibian biodiversity under climate change. Actions were...

  4. Human attitudes towards herpetofauna: the influence of folklore and negative values on the conservation of amphibians and reptiles in Portugal.

    Science.gov (United States)

    Ceríaco, Luis Mp

    2012-02-08

    Human values and folklore of wildlife strongly influence the effectiveness of conservation efforts. These values and folklore may also vary with certain demographic characteristics such as gender, age, or education. Reptiles and amphibians are among the least appreciated of vertebrates and are victims of many negative values and wrong ideas resulting from the direct interpretation of folklore. We try to demonstrate how these values and folklore can affect the way people relate to them and also the possible conservation impacts on these animals. A questionnaire survey distributed to 514 people in the district of Évora, Portugal, was used to obtain data regarding the hypothesis that the existence of wrong ideas and negative values contributes to the phenomenon of human-associated persecution of these animals. A structural equation model was specified in order to confirm the hypothesis about the possible relationships between the presence of perceptions and negative values about amphibians and reptiles and persecution and anti-conservation attitudes. Sociodemographic variables were also added. The results of the model suggest that the presence of folklore and negative values clearly predicts persecution and anti-conservation attitudes towards amphibians and reptiles. Also, the existence of folklore varies sociodemographically, but negative values concerning these animals are widespread in the population. With the use of structural equation models, this work is a contribution to the study of how certain ideas and values can directly influence human attitudes towards herpetofauna and how they can be a serious conservation issue.

  5. Plasticity and Adult Neurogenesis in Amphibians and Reptiles: More Questions than Answers.

    Science.gov (United States)

    Powers, Alice Schade

    2016-08-24

    Studies of the relationship between behavioral plasticity and new cells in the adult brain in amphibians and reptiles are sparse but demonstrate that environmental and hormonal variables do have an effect on the amount of cell proliferation and/or migration. The variables that are reviewed here are: enriched environment, social stimulation, spatial area use, season, photoperiod and temperature, and testosterone. Fewer data are available for amphibians than for reptiles, but for both groups many issues are still to be resolved. It is to be hoped that the questions raised here will generate more answers in future studies. © 2016 S. Karger AG, Basel.

  6. The cancer paradigms of mammalian regeneration: can mammals regenerate as amphibians?

    Science.gov (United States)

    Sarig, Rachel; Tzahor, Eldad

    2017-04-01

    Regeneration in mammals is restricted to distinct tissues and occurs mainly by expansion and maturation of resident stem cells. During regeneration, even subtle mutations in the proliferating cells may cause a detrimental effect by eliciting abnormal differentiation or malignant transformation. Indeed, cancer in mammals has been shown to arise through deregulation of stem cells maturation, which often leads to a differentiation block and cell transformation. In contrast, lower organisms such as amphibians retain a remarkable regenerative capacity in various organs, which occurs via de- and re-differentiation of mature cells. Interestingly, regenerating amphibian cells are highly resistant to oncogenic transformation. Therapeutic approaches to improve mammalian regeneration mainly include stem-cell transplantations; but, these have proved unsuccessful in non-regenerating organs such as the heart. A recently developed approach is to induce de-differentiation of mature cardiomyocytes using factors that trigger their re-entry into the cell cycle. This novel approach raises numerous questions regarding the balance between transformation and regeneration induced by de-differentiation of mature mammalian somatic cells. Can this balance be controlled artificially? Do de-differentiated cells acquire the protection mechanisms seen in regenerating cells of lower organisms? Is this model unique to the cardiac tissue, which rarely develops tumors? This review describes regeneration processes in both mammals and lower organisms and, particularly, the ability of regenerating cells to avoid transformation. By comparing the characteristics of mammalian embryonic and somatic cells, we discuss therapeutic strategies of using various cell populations for regeneration. Finally, we describe a novel cardiac regeneration approach and its implications for regenerative medicine. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email

  7. Coastal Resources Atlas: Long Island: REPTILES (Reptile and Amphibian Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for sea turtles, estuarine turtles, and amphibians for Long Island, New York. Vector polygons in this data...

  8. Fetal adaptations for viviparity in amphibians.

    Science.gov (United States)

    Wake, Marvalee H

    2015-08-01

    Live-bearing has evolved in all three orders of amphibians--frogs, salamanders, and caecilians. Developing young may be either yolk dependent, or maternal nutrients may be supplied after yolk is resorbed, depending on the species. Among frogs, embryos in two distantly related lineages develop in the skin of the maternal parents' backs; they are born either as advanced larvae or fully metamorphosed froglets, depending on the species. In other frogs, and in salamanders and caecilians, viviparity is intraoviductal; one lineage of salamanders includes species that are yolk dependent and born either as larvae or metamorphs, or that practice cannibalism and are born as metamorphs. Live-bearing caecilians all, so far as is known, exhaust yolk before hatching and mothers provide nutrients during the rest of the relatively long gestation period. The developing young that have maternal nutrition have a number of heterochronic changes, such as precocious development of the feeding apparatus and the gut. Furthermore, several of the fetal adaptations, such as a specialized dentition and a prolonged metamorphosis, are homoplasious and present in members of two or all three of the amphibian orders. At the same time, we know little about the developmental and functional bases for fetal adaptations, and less about the factors that drive their evolution and facilitate their maintenance. © 2014 Wiley Periodicals, Inc.

  9. Ovarian control and monitoring in amphibians.

    Science.gov (United States)

    Calatayud, N E; Stoops, M; Durrant, B S

    2018-03-15

    Amphibian evolution spans over 350 million years, consequently this taxonomic group displays a wide, complex array of physiological adaptations and their diverse modes of reproduction are a prime example. Reproduction can be affected by taxonomy, geographic and altitudinal distribution, and environmental factors. With some exceptions, amphibians can be categorized into discontinuous (strictly seasonal) and continuous breeders. Temperature and its close association with other proximate and genetic factors control reproduction via a tight relationship with circadian rhythms which drive genetic and hormonal responses to the environment. In recent times, the relationship of proximate factors and reproduction has directly or indirectly lead to the decline of this taxonomic group. Conservationists are tackling the rapid loss of species through a wide range of approaches including captive rescue. However, there is still much to be learned about the mechanisms of reproductive control and its requirements in order to fabricate species-appropriate captive environments that address a variety of reproductive strategies. As with other taxonomic groups, assisted reproductive technologies and other reproductive monitoring tools such as ultrasound, hormone analysis and body condition indices can assist conservationists in optimizing captive husbandry and breeding. In this review we discuss some of the mechanisms of ovarian control and the different tools being used to monitor female reproduction. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. Interactions of an insecticide with competition and pond drying in amphibian communities

    Science.gov (United States)

    Boone, M.D.; Semlitsch, R.D.

    2002-01-01

    Amphibian populations are often imbedded in agricultural landscapes. Therefore the potential for contamination of their habitat is considerable. Our study examined the effects of an insecticide (carbaryl, a neurotoxin), on larval amphibian communities experiencing natural stresses of competition for resources, predation, and pond drying. In a set of experimental ponds, tadpoles of three anuran species (southern leopard frog [Rana sphenocephala], plains leopard frog [R. blairi], and the Woodhouse's toad [Bufo woodhousii]) were added to 1000-L ponds containing leaf litter, plankton, two newts (Notophthalmus viridescens), and four overwintered green frog (R. clamitans) tadpoles. We manipulated the overall tadpole density (low or high), pond hydroperiod (constant or drying), and chemical exposure (0, 3.5, 5.0, or 7.0 mg/L carbaryl) of the ponds. We measured mass, time, and survival to metamorphosis to determine treatment effects. Carbaryl positively affected Woodhouse's toad survival, although it had a negligible effect on both leopard frog species. Tadpole density interacted with the chemical treatment: Proportionately more Woodhouse's toads survived to metamorphosis in high-density environments than in low-density or control environments. Greater survival may be an indirect effect of increased algal food resources from carbaryl exposure. Most newts lost mass over the course of the experiment, although ponds with drying hydroperiods and high anuran density were the least favorable environments. Overwintered green frogs exposed to carbaryl had longer larval periods on average than did green frogs in control ponds. Our study demonstrated that even sublethal, short-lived contaminants can alter natural communities in ways that cannot be predicted from simple, one-factor studies.

  11. Identification of individual foothill yellow-legged frogs (Rana boylii) using chin pattern photographs: a non-invasive and effective method for small population studies

    Science.gov (United States)

    K.R. Marlow; K.D. Wiseman; Clara Wheeler; J.E.  Drennan; R.E.  Jackman

    2016-01-01

    The ability to identify individual animals is a valuable tool in the study of amphibian population dynamics, movement ecology, social behavior, and habitat use. Numerous methods of marking amphibians have been employed including the use of passive integrated transponder (PIT) tags, radio-transmitters, elastomers, branding, and mutilation techniques such as toe...

  12. Phylogenetic signals in the climatic niches of the world's amphibians

    DEFF Research Database (Denmark)

    Hof, Christian; Rahbek, Carsten; Araújo, Miguel B.

    2010-01-01

    amphibian orders and across biogeographical regions. To our knowledge, this is the first study providing a comprehensive analysis of the phylogenetic signal in species climatic niches for an entire clade across the world. Even though our results do not provide a strong test of the niche conservatism......The question of whether closely related species share similar ecological requirements has attracted increasing attention, because of its importance for understanding global diversity gradients and the impacts of climate change on species distributions. In fact, the assumption that related species...... are also ecologically similar has often been made, although the prevalence of such a phylogenetic signal in ecological niches remains heavily debated. Here, we provide a global analysis of phylogenetic niche relatedness for the world's amphibians. In particular, we assess which proportion of the variance...

  13. Microcosm investigations of stormwater pond sediment toxicity to embryonic and larval amphibians: Variation in sensitivity among species

    Energy Technology Data Exchange (ETDEWEB)

    Snodgrass, Joel W. [Department of Biological Sciences, Towson University, 8000 York Road, Towson, MD 21252 (United States)], E-mail: jsnodgrass@towson.edu; Casey, Ryan E. [Department of Chemistry, Towson University, 8000 York Road, Towson, MD 21252 (United States); Joseph, Debra; Simon, Judith A. [Department of Biological Sciences, Towson University, 8000 York Road, Towson, MD 21252 (United States)

    2008-07-15

    Stormwater ponds have become common features of modern development and often represent significant amounts of open space in urbanized areas. Although stormwater ponds may provide habitat for wildlife, factors responsible for producing variation in wildlife use of ponds have received limited attention. To investigate the role of variation in species tolerances of pollutants in structuring pond-breeding amphibian assemblages, we exposed species tolerant (Bufo americanus) and not tolerant (Rana sylvatica) of urbanization to pond sediments in laboratory microcosms. Pond microcosms had elevated sediment metal levels and chloride water concentrations. Among R. sylvatica embryos, exposure to pond sediments resulted in 100% mortality. In contrast, B. americanus embryos and larvae experienced only sublethal effects (i.e., reduced size at metamorphosis) due to pond sediment exposure. Our results suggest variation in pollutant tolerance among early developmental stages of amphibians may act in concert with terrestrial habitat availability to structure amphibian assemblages associated with stormwater ponds. - Variation among species in sensitivity to pollutants can influence stormwater pond amphibian assemblages.

  14. A predictive framework and review of the ecological impacts of exotic plant invasions on reptiles and amphibians.

    Science.gov (United States)

    Martin, Leigh J; Murray, Brad R

    2011-05-01

    The invasive spread of exotic plants in native vegetation can pose serious threats to native faunal assemblages. This is of particular concern for reptiles and amphibians because they form a significant component of the world's vertebrate fauna, play a pivotal role in ecosystem functioning and are often neglected in biodiversity research. A framework to predict how exotic plant invasion will affect reptile and amphibian assemblages is imperative for conservation, management and the identification of research priorities. Here, we present a new predictive framework that integrates three mechanistic models. These models are based on exotic plant invasion altering: (1) habitat structure; (2) herbivory and predator-prey interactions; (3) the reproductive success of reptile and amphibian species and assemblages. We present a series of testable predictions from these models that arise from the interplay over time among three exotic plant traits (growth form, area of coverage, taxonomic distinctiveness) and six traits of reptiles and amphibians (body size, lifespan, home range size, habitat specialisation, diet, reproductive strategy). A literature review provided robust empirical evidence of exotic plant impacts on reptiles and amphibians from each of the three model mechanisms. Evidence relating to the role of body size and diet was less clear-cut, indicating the need for further research. The literature provided limited empirical support for many of the other model predictions. This was not, however, because findings contradicted our model predictions but because research in this area is sparse. In particular, the small number of studies specifically examining the effects of exotic plants on amphibians highlights the pressing need for quantitative research in this area. There is enormous scope for detailed empirical investigation of interactions between exotic plants and reptile and amphibian species and assemblages. The framework presented here and further testing of

  15. Radioautographic investigation of retinal growth in mature amphibians

    International Nuclear Information System (INIS)

    Svistunov, S.A.; Mitashov, V.I.

    1986-01-01

    Growth of the retina was studied in mature intact amphibians, tritons, axolotls, ambystomas and clawed frogs, for six months using multiple injection of 3 H-thymidine. It was established that the source of replenishment of the retina by new cells is its terminal zone in all animals investigated. This is attested to by the gradual migration of labeled cells from the growth zone into differentiated layers of the retina. The most intensely labeled cells occupy a distal position relative to other labeled cells, therefore marking the boundary between the initial part of the retina, not containing labeled nuclei, and the part being augmented. For each species studied, a level of proliferative activity is characteristic for cells of the terminal zone, which decreases in the order axolotl-clawed frog-triton -ambystoma. In the axolotl and additional growth zone is noted in the retina, in addition to the terminal, which is located in the area of the unclosed section of the embryonic fissure. Results obtained serve as a basis for the regenerative potentials of eye tissues revealed previously in these amphibian species

  16. Amphibian and reptile response to prescribed burning and thinning in pine-hardwood forests: pre-treatment results

    Science.gov (United States)

    William B. Sutton; Yong Wang; Callie J. Schweitzer

    2010-01-01

    Analysis of pretreatment data is essential to determine long-term effects of forest management on amphibians and reptiles. We present pre-treatment amphibian and reptile capture data from April 2005 to May 2006 for a long-term study on herpetofaunal response to prescribed burning and tree thinning in the William B. Bankhead National Forest, AL, United States....

  17. Efficacy of SYBR 14/propidium iodide viability stain for the amphibian chytrid fungus Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Stockwell, M P; Clulow, J; Mahony, M J

    2010-01-25

    The amphibian chytrid fungus Batrachochytrium dendrobatidis is a recently described pathogen that has been implicated as a causal agent in the global decline in amphibians. Research into its biology and epidemiology has frequently involved in vitro experimentation. However, this research is currently limited by the inability to differentiate between viable and inviable zoospores. Stains are frequently used to determine cell viability, and this study tested a 2-colour fluorescence assay for the detection and quantification of viable B. dendrobatidis zoospores. The results show that the nucleic acid stains SYBR 14 and propidium iodide are effective in distinguishing live from dead zoospores, and a protocol has been optimized for their use. This viability assay provides an efficient and reliable tool that will have applications in B. dendrobatidis challenge and amphibian exposure experiments.

  18. Healthy Eating Habits among the Population of Serbia: Gender and Age Differences

    OpenAIRE

    Jovi?i?, Ana ?.

    2015-01-01

    ABSTRACT The purpose of the study is to examine healthy eating habits of the population of Serbia through three dimensions: knowledge, problems, and feelings as well as to determine whether there are any differences between genders and among different age-groups. The research instrument was an Eating Habits Questionnaire (EHQ) which consisted of 35 items. There were 382 respondents involved in the study. The reliability and factor structure of the questionnaire were verified by using factor a...

  19. Towards gene banking amphibian maternal germ lines: short-term incubation, cryoprotectant tolerance and cryopreservation of embryonic cells of the frog, Limnodynastes peronii.

    Science.gov (United States)

    Lawson, Bianca; Clulow, Simon; Mahony, Michael J; Clulow, John

    2013-01-01

    Gene banking is arguably the best method available to prevent the loss of genetic diversity caused by declines in wild populations, when the causes of decline cannot be halted or reversed. For one of the most impacted vertebrate groups, the amphibians, gene banking technologies have advanced considerably, and gametes from the male line can be banked successfully for many species. However, cryopreserving the female germ line remains challenging, with attempts at cryopreserving oocytes unsuccessful due to their large size and yolk content. One possible solution is to target cryopreservation of early embryos that contain the maternal germ line, but consist of smaller cells. Here, we investigate the short term incubation, cryoprotectant tolerance, and cryopreservation of dissociated early embryonic cells from gastrulae and neurulae of the Striped Marsh Frog, Limnodynastes peronii. Embryos were dissociated and cells were incubated for up to 24 hours in various media. Viability of both gastrula and neurula cells remained high (means up to 40-60%) over 24 hours of incubation in all media, although viability was maintained at a higher level in Ca(2+)-free Simplified Amphibian Ringer; low speed centrifugation did not reduce cell viability. Tolerance of dissociated embryonic cells was tested for two cryoprotectants, glycerol and dimethyl sulphoxide; dissociated cells of both gastrulae and neurulae were highly tolerant to both-indeed, cell viability over 24 hours was higher in media containing low-to-medium concentrations than in equivalent cryoprotectant-free media. Viability over 24 hours was lower in concentrations of cryoprotectant higher than 10%. Live cells were recovered following cryopreservation of both gastrula and neurula cells, but only at low rates. Optimal cryodiluents were identified for gastrula and neurula cells. This is the first report of a slow cooling protocol for cryopreservation of amphibian embryonic cells, and sets future research directions for

  20. Towards gene banking amphibian maternal germ lines: short-term incubation, cryoprotectant tolerance and cryopreservation of embryonic cells of the frog, Limnodynastes peronii.

    Directory of Open Access Journals (Sweden)

    Bianca Lawson

    Full Text Available Gene banking is arguably the best method available to prevent the loss of genetic diversity caused by declines in wild populations, when the causes of decline cannot be halted or reversed. For one of the most impacted vertebrate groups, the amphibians, gene banking technologies have advanced considerably, and gametes from the male line can be banked successfully for many species. However, cryopreserving the female germ line remains challenging, with attempts at cryopreserving oocytes unsuccessful due to their large size and yolk content. One possible solution is to target cryopreservation of early embryos that contain the maternal germ line, but consist of smaller cells. Here, we investigate the short term incubation, cryoprotectant tolerance, and cryopreservation of dissociated early embryonic cells from gastrulae and neurulae of the Striped Marsh Frog, Limnodynastes peronii. Embryos were dissociated and cells were incubated for up to 24 hours in various media. Viability of both gastrula and neurula cells remained high (means up to 40-60% over 24 hours of incubation in all media, although viability was maintained at a higher level in Ca(2+-free Simplified Amphibian Ringer; low speed centrifugation did not reduce cell viability. Tolerance of dissociated embryonic cells was tested for two cryoprotectants, glycerol and dimethyl sulphoxide; dissociated cells of both gastrulae and neurulae were highly tolerant to both-indeed, cell viability over 24 hours was higher in media containing low-to-medium concentrations than in equivalent cryoprotectant-free media. Viability over 24 hours was lower in concentrations of cryoprotectant higher than 10%. Live cells were recovered following cryopreservation of both gastrula and neurula cells, but only at low rates. Optimal cryodiluents were identified for gastrula and neurula cells. This is the first report of a slow cooling protocol for cryopreservation of amphibian embryonic cells, and sets future research

  1. Population pharmacokinetics of adefovir dipivoxil tablets in healthy Chinese volunteers.

    Science.gov (United States)

    Huang, Jihan; Zhang, Yaping; Huang, Xiaohui; Li, Lujin; Li, Yunfei; Wang, Kun; Yang, Juan; He, Yingchun; Lv, Yinghua; Zheng, Qingshan

    2014-01-01

    To develop a population pharmacokinetic model of adefovir dipivoxil in healthy volunteers and evaluate the effect of individual factors on the pharmacokinetics of adefovir dipivoxil. Plasma concentration data collected from 32 healthy Chinese subjects in a Phase I clinical study was pooled. Subjects received a single oral dose of 10 mg, 20 mg, or 30 mg adefovir dipivoxil, or multiple doses of 10 mg once a day for 9 days. Plasma concentrations of adefovir dipivoxil were measured using a validated liquid chromatography-mass spectrometric method. A nonlinear mixed-effect model was used to analyze the plasma concentration data of adefovir dipivoxil in healthy volunteers and to calculate the relevant parameters as well as inter- and intra-individual variability. The time course of adefovir dipivoxil concentration is best described by a first-order absorption and first-order elimination two-compartment model with lag time. The final estimate of total body clearance (CL) is 56.9 L/h and 78.7 L/h for single and multiple dosing regimen, respectively; the volume distribution of the central compartment (V2) is 106 L; inter-compartmental clearance (Q) is 220 L/h; volume distribution of the peripheral compartment (V3) is 498 L and 800 L for single and multiple dosing regimen, respectively; absorption rate is 0.509 h-1; and lag time is 0.315 hours. The inter-individual variabilities of CL and V2 were 22.4% and 58.9%, respectively. The proportional error of residual variability is 14.1% and the additive error is 0.30 ng/L. The final pharmacokinetic model was evaluated using a bootstrap method. A nonlinear mixed effect model for oral adefovir dipivoxil formulations was developed in healthy Chinese subjects. A multiple dosing regimen may significantly increase the body clearance and volume distribution of the peripheral compartment compared to a single dosing regimen. *These authors contribute equally to this work.

  2. Quaternary climate changes explain diversity among reptiles and amphibians

    DEFF Research Database (Denmark)

    Bastos Araujo, Miguel; Nogués-Bravo, David; Diniz-Filho, Alexandre F.

    2008-01-01

    debated without reaching consensus. Here, we test the proposition that European species richness of reptiles and amphibians is driven by climate changes in the Quaternary. We find that climate stability between the Last Glacial Maximum (LGM) and the present day is a better predictor of species richness...

  3. TEMPERATURE AND PRECIPITATION AS PREDICTORS OF SPECIES RICHNESS IN NORTHERN ANDEAN AMPHIBIANS FROM COLOMBIA

    Directory of Open Access Journals (Sweden)

    Ortiz-Yusty Carlos Eduardo

    2013-07-01

    Full Text Available Our objective was to explore the spatial distribution patterns of amphibian speciesrichness in Antioquia, as model for the tropical Andes, and determine how annualmean temperature, annual precipitation, and elevation range influence it. We alsobriefly compare local and global regression models for estimating the relationbetween environmental variables and species richness. Distribution maps for 223amphibian species and environmental variables were generalized onto grid mapsof 752 blocks each covering the entire Department of Antioquia. We explored therelationship between species richness and environment using two global regressionmodels (the Ordinary Least Squares “OLS” and Generalized Linear Squares“GLS” models and one local model (the Geographically Weighted Regression“GWR” model. We found a significant relationship between species richness andenvironmental variables (GLS r2: 0.869; GRW r2: 0.929. The GLS model efficientlyincorporated the spatial autocorrelation effect and handled spatial dependencein the regression error terms while the GWR model showed the best fit (r2 andbalance between number of parameters and fit (AICc. GWR parameters show widevariation within the study area, indicating that relationship between species richnessand climate is spatially complex. Temperature was the most important variablein the GLS and GWR models, and altitude range the least significant. The strongrelationship between environment and amphibian richness is possibly due to lifehistory traits of amphibians, such as ectothermy and water dependency to completethe life cycle

  4. Transitions between sex-determining systems in reptiles and amphibians.

    Science.gov (United States)

    Sarre, Stephen D; Ezaz, Tariq; Georges, Arthur

    2011-01-01

    Important technological advances in genomics are driving a new understanding of the evolution of sex determination in vertebrates. In particular, comparative chromosome mapping in reptiles has shown an intriguing distribution of homology in sex chromosomes across reptile groups. When this new understanding is combined with the widespread distribution of genetic and temperature-dependent sex-determination mechanisms among reptiles, it is apparent that transitions between modes have occurred many times, as they have for amphibians (particularly between male and female heterogamety). It is also likely that thermosensitivity in sex determination is a key factor in those transitions in reptiles, and possibly in amphibians too. New models of sex determination involving temperature thresholds are providing the framework for the investigation of transitions and making possible key predictions about the homologies and sex-determination patterns expected among taxa in these groups. Molecular cytogenetics and other genomic approaches are essential to providing the fundamental material necessary to make advances in this field.

  5. Prevalence of viral hepatitis (B and C serological markers in healthy working population

    Directory of Open Access Journals (Sweden)

    José Luis Calleja-Panero

    2013-06-01

    Full Text Available Introduction and objectives: prevalence of viral hepatitis (B and C changes geographically. Our aim was to determinate the prevalence of hepatitis B (HBV and hepatitis C virus (HCV serological markers in healthy working population and to describe the epidemiological characteristics associated to its presence. Methods: blood samples and epidemiological data of 5,017 healthy workers from Murcia and Madrid were recorded prospectively. Results: a total of 5,017 healthy volunteers participated. Mean age 39 ± 11 years, men predominance (73 %. Prevalence of serological markers of HCV and HBV was 0.6 % and 0.7 %. Age of patients with HCV antibody was significantly higher (43 ± 9 years vs. 39 ± 11 years; p = 0.03. We observed significant differences in liver test values (alanine aminotransferase [ALT] 64 ± 56 IU/L vs. 28 ± 20 IU/L; p < 0.001; aspartate aminotransferase [AST] (51 ± 45 IU/L vs. 23 ± 12 IU/L; p < 0.001 and in gamma-glutamyltransferase (GGT value (104 ± 122 IU/L vs. 37 ± 46 IU/L; p < 0.001. The presence of HCV antibody was related significantly to previous transfusion (13 % vs. 5 %; p = 0.03, tattoos (29 % vs. 13 %; p < 0.01, intravenous drug addiction (13 % vs. 0.2 %; p < 0.001 and coexistence with people with positive HCV antibody (16 % vs. 4 %; p < 0.001. In HBV no differences in basal characteristics were observed with exception in AST values (29 ± 15 IU/L vs. 23 ± 12 IU/L; p < 0.01. Hepatitis B surface antigen (HBsAg was related significantly to previous transfusion (15 % vs. 5 %; p < 0.01, tattoos (26 % vs. 14 %; p = 0.04 and coexistence with people with positive HBsAg (17 % vs. 4 %; p < 0.001. Conclusions: prevalence of serological markers in healthy working population is low. Risk factors for infection were previous transfusion and tattoos. Intravenous drug addiction was only a risk factor in HCV.

  6. Characterizing the width of amphibian movements during postbreeding migration.

    Science.gov (United States)

    Coster, Stephanie S; Veysey Powell, Jessica S; Babbitt, Kimberly J

    2014-06-01

    Habitat linkages can help maintain connectivity of animal populations in developed landscapes. However, the lack of empirical data on the width of lateral movements (i.e., the zigzagging of individuals as they move from one point to point another) makes determining the width of such linkages challenging. We used radiotracking data from wood frogs (Lithobates sylvaticus) and spotted salamanders (Ambystoma maculatum) in a managed forest in Maine (U.S.A.) to characterize movement patterns of populations and thus inform planning for the width of wildlife corridors. For each individual, we calculated the polar coordinates of all locations, estimated the vector sum of the polar coordinates, and measured the distance from each location to the vector sum. By fitting a Gaussian distribution over a histogram of these distances, we created a population-level probability density function and estimated the 50th and 95th percentiles to determine the width of lateral movement as individuals progressed from the pond to upland habitat. For spotted salamanders 50% of lateral movements were ≤13 m wide and 95% of movements were ≤39 m wide. For wood frogs, 50% of lateral movements were ≤17 m wide and 95% of movements were ≤ 51 m wide. For both species, those individuals that traveled the farthest from the pond also displayed the greatest lateral movement. Our results serve as a foundation for spatially explicit conservation planning for pond-breeding amphibians in areas undergoing development. Our technique can also be applied to movement data from other taxa to aid in designing habitat linkages. © 2014 Society for Conservation Biology.

  7. Chytrid fungus acts as a generalist pathogen infecting species-rich amphibian families in Brazilian rainforests.

    Science.gov (United States)

    Valencia-Aguilar, Anyelet; Ruano-Fajardo, Gustavo; Lambertini, Carolina; da Silva Leite, Domingos; Toledo, Luís Felipe; Mott, Tamí

    2015-05-11

    The fungus Batrachochytrium dendrobatidis (Bd) is among the main causes of declines in amphibian populations. This fungus is considered a generalist pathogen because it infects several species and spreads rapidly in the wild. To date, Bd has been detected in more than 100 anuran species in Brazil, mostly in the southern portion of the Atlantic forest. Here, we report survey data from some poorly explored regions; these data considerably extend current information on the distribution of Bd in the northern Atlantic forest region. In addition, we tested the hypothesis that Bd is a generalist pathogen in this biome. We also report the first positive record for Bd in an anuran caught in the wild in Amazonia. In total, we screened 90 individuals (from 27 species), of which 39 individuals (from 22 species) were Bd-positive. All samples collected in Bahia (2 individuals), Pernambuco (3 individuals), Pará (1 individual), and Minas Gerais (1 individual) showed positive results for Bd. We found a positive correlation between anuran richness per family and the number of infected species in the Atlantic forest, supporting previous observations that Bd lacks strong host specificity; of 38% of the anuran species in the Atlantic forest that were tested for Bd infection, 25% showed positive results. The results of our study exemplify the pandemic and widespread nature of Bd infection in amphibians.

  8. Projecting the Global Distribution of the Emerging Amphibian Fungal Pathogen, Batrachochytrium dendrobatidis, Based on IPCC Climate Futures.

    Directory of Open Access Journals (Sweden)

    Gisselle Yang Xie

    Full Text Available Projected changes in climate conditions are emerging as significant risk factors to numerous species, affecting habitat conditions and community interactions. Projections suggest species range shifts in response to climate change modifying environmental suitability and is supported by observational evidence. Both pathogens and their hosts can shift ranges with climate change. We consider how climate change may influence the distribution of the emerging infectious amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd, a pathogen associated with worldwide amphibian population losses. Using an expanded global Bd database and a novel modeling approach, we examined a broad set of climate metrics to model the Bd-climate niche globally and regionally, then project how climate change may influence Bd distributions. Previous research showed that Bd distribution is dependent on climatic variables, in particular temperature. We trained a machine-learning model (random forest with the most comprehensive global compilation of Bd sampling records (~5,000 site-level records, mid-2014 summary, including 13 climatic variables. We projected future Bd environmental suitability under IPCC scenarios. The learning model was trained with combined worldwide data (non-region specific and also separately per region (region-specific. One goal of our study was to estimate of how Bd spatial risks may change under climate change based on the best available data. Our models supported differences in Bd-climate relationships among geographic regions. We projected that Bd ranges will shift into higher latitudes and altitudes due to increased environmental suitability in those regions under predicted climate change. Specifically, our model showed a broad expansion of areas environmentally suitable for establishment of Bd on amphibian hosts in the temperate zones of the Northern Hemisphere. Our projections are useful for the development of monitoring designs in these areas

  9. Does a healthy lifestyle behaviour influence the prognosis of low back pain among men and women in a general population? A population-based cohort study.

    Science.gov (United States)

    Bohman, Tony; Alfredsson, Lars; Jensen, Irene; Hallqvist, Johan; Vingård, Eva; Skillgate, Eva

    2014-12-30

    To study the influence of healthy lifestyle behaviour on the prognosis of occasional low back pain among men and women in a general population. Cohort study with a 4-year follow-up. General population in Stockholm County, Sweden. The study sample comprised 3938 men and 5056 women aged 18-84 from the Stockholm Public Health Cohort reporting occasional low back pain in the baseline questionnaire 2006. Lifestyle factors and potential confounders were assessed at baseline. The lifestyle factors smoking habits, alcohol consumption, leisure physical activity and consumption of fruit and vegetables were dichotomised using recommendations for a health-enhancing lifestyle and combined to form the exposure variable 'healthy lifestyle behaviour'. The exposure was categorised into five levels according to the number of healthy lifestyle factors met. The follow-up questionnaire in 2010 gave information about the outcome, long duration troublesome low back pain. Crude and adjusted binomial regression models were applied to estimate the association between the exposure and the outcome analysing men and women separately. The risk of developing long duration troublesome low back pain among women with occasional low back pain decreased with increasing healthy lifestyle behaviour (trend test: p=0.006). 21% (28/131) among women with no healthy lifestyle factor (reference) experienced the outcome compared to 9% (36/420) among women with all four factors. Compared to the reference group, the risk was reduced by 35% (RR 0.65, 95% CI 0.44 to 0.96) for women with one healthy lifestyle factor and 52% (RR 0.48, 95% CI 0.31 to 0.77) for women with all four healthy lifestyle factors. There were no clear associations found among men. Healthy lifestyle behaviour seems to decrease the risk of developing long duration troublesome low back pain among women with occasional low back pain and may be recommended to improve the prognosis. Published by the BMJ Publishing Group Limited. For permission to

  10. A checklist of the amphibians and reptiles of Honduras, with additions, comments on taxonomy, some recent taxonomic decisions, and areas of further studies needed.

    Science.gov (United States)

    Mccranie, James R

    2015-03-13

    An updated checklist of the amphibians and reptiles of Honduras is provided. The list includes three amphibian species (Ptychohyla euthysanota, Bolitoglossa odonnelli, Oedipina chortiorum) and two reptile species (Laemanctus waltersi [elevated from subspecies status], Epictia phenops) not included in the most recent checklist of the amphibians and reptiles of the country. Also, one amphibian genus and species (Triprion petasatus) is removed from the country list and one Honduran lizard (Ctenosaura praeocularis) is synonymized with an older name. Comments where more study is needed are also included where pertinent. Authors, dates, and original spellings of the higher-level taxonomy of all taxa covered herein are also given. A total of 401 species (137 amphibians and 264 reptiles) are now known from the country with 111 species (27.7%) being Honduran endemics (52 amphibians and 59 reptiles).

  11. Neotropical Amphibian Declines Affect Stream Ecosystem Properties

    Science.gov (United States)

    Connelly, S.; Pringle, C. M.; Bixby, R. J.; Whiles, M. R.; Lips, K. R.; Brenes, R.; Colon-Gaud, J. C.; Kilham, S.; Hunte-Brown, M.

    2005-05-01

    Global declines of amphibians are well documented, yet effects of these dramatic losses on ecosystem structure and function are poorly understood. As part of a larger collaborative project, we compared two upland Panamanian streams. Both streams are biologically and geologically similar; however, one stream (Fortuna) has recently experienced almost complete extirpation of stream-dwelling frogs, while the other (Cope) still has intact populations. We experimentally excluded tadpoles from localized areas in each stream. We then compared chlorophyll a, algal community composition, ash-free dry mass (AFDM), inorganic matter, and insect assemblages in control and exclusion areas. Additionally, we sampled the natural substrate of both streams monthly for chlorophyll a, algal community composition, AFDM, and inorganic matter. At Cope, chlorophyll a, AFDM, and inorganic matter were greater in areas where tadpoles were excluded than in their presence. Numbers of dominant algal species (e.g., Nupela praecipua and Eunotia siolii) were greater in the exclusion versus control treatments. Monthly sampling of natural substrate indicated higher chlorophyll a and AFDM at Cope compared to Fortuna. Our data suggest that stream-dwelling anuran larvae have significant impacts on algal communities. These results also have implications for predicting the relevance of short-term experimental manipulations to long-term, whole-stream processes.

  12. Effects of land-use change on community composition of tropical amphibians and reptiles in Sulawesi, Indonesia.

    Science.gov (United States)

    Wanger, Thomas C; Iskandar, Djoko T; Motzke, Iris; Brook, Barry W; Sodhi, Navjot S; Clough, Yann; Tscharntke, Teja

    2010-06-01

    Little is known about the effects of anthropogenic land-use change on the amphibians and reptiles of the biodiverse tropical forests of Southeast Asia. We studied a land-use modification gradient stretching from primary forest, secondary forest, natural-shade cacao agroforest, planted-shade cacao agroforest to open areas in central Sulawesi, Indonesia. We determined species richness, abundance, turnover, and community composition in all habitat types and related these to environmental correlates, such as canopy heterogeneity and thickness of leaf litter. Amphibian species richness decreased systematically along the land-use modification gradient, but reptile richness and abundance peaked in natural-shade cacao agroforests. Species richness and abundance patterns across the disturbance gradient were best explained by canopy cover and leaf-litter thickness in amphibians and by canopy heterogeneity and cover in reptiles. Amphibians were more severely affected by forest disturbance in Sulawesi than reptiles. Heterogeneous canopy cover and thick leaf litter should be maintained in cacao plantations to facilitate the conservation value for both groups. For long-term and sustainable use of plantations, pruned shade trees should be permanently kept to allow rejuvenation of cacao and, thus, to prevent repeated forest encroachment.

  13. The montane forest associated amphibian species of the Taita Hills ...

    African Journals Online (AJOL)

    The montane forest associated amphibian species of the Taita Hills, Kenya. ... They are surrounded by the dry Tsavo plains. ... The biodiversity importance of the Taita Hills lies with the number of endemics per unit of area of remaining forest, ...

  14. Comparative performance of the 16S rRNA gene in DNA barcoding of amphibians

    Directory of Open Access Journals (Sweden)

    Chiari Ylenia

    2005-03-01

    Full Text Available Abstract Background Identifying species of organisms by short sequences of DNA has been in the center of ongoing discussions under the terms DNA barcoding or DNA taxonomy. A C-terminal fragment of the mitochondrial gene for cytochrome oxidase subunit I (COI has been proposed as universal marker for this purpose among animals. Results Herein we present experimental evidence that the mitochondrial 16S rRNA gene fulfills the requirements for a universal DNA barcoding marker in amphibians. In terms of universality of priming sites and identification of major vertebrate clades the studied 16S fragment is superior to COI. Amplification success was 100% for 16S in a subset of fresh and well-preserved samples of Madagascan frogs, while various combination of COI primers had lower success rates.COI priming sites showed high variability among amphibians both at the level of groups and closely related species, whereas 16S priming sites were highly conserved among vertebrates. Interspecific pairwise 16S divergences in a test group of Madagascan frogs were at a level suitable for assignment of larval stages to species (1–17%, with low degrees of pairwise haplotype divergence within populations (0–1%. Conclusion We strongly advocate the use of 16S rRNA as standard DNA barcoding marker for vertebrates to complement COI, especially if samples a priori could belong to various phylogenetically distant taxa and false negatives would constitute a major problem.

  15. Vitamin-D receptor (VDR) gene polymorphisms (Taq-I & Apa-I) in Syrian healthy population.

    Science.gov (United States)

    Haddad, Shaden

    2014-12-01

    The vitamin D endocrine system regulates bone metabolism and calcium homeostasis as well as cellular proliferation and differentiation. Vitamin D receptor (VDR) mediates Vit-D activity, thus VDR gene polymorphisms may correlate with different diseases. This study aimed to determine the distribution of VDR gene (Taq-I and Apa-I) polymorphisms using a RFLP in unrelated normal healthy individuals of Syrian population. Allelic frequencies were 65% vs 35% and 66% vs 34% for T vs t and A vs a alleles, respectively. Genotype distribution was 36%, 58% and 6% for TT, Tt and tt and 42%, 47% and 10% for AA, Aa and aa, respectively. These results demonstrate that the frequency and distribution of the VDR polymorphisms in Syrian population are different from other populations worldwide.

  16. Human attitudes towards herpetofauna: The influence of folklore and negative values on the conservation of amphibians and reptiles in Portugal

    Science.gov (United States)

    2012-01-01

    Background Human values and folklore of wildlife strongly influence the effectiveness of conservation efforts. These values and folklore may also vary with certain demographic characteristics such as gender, age, or education. Reptiles and amphibians are among the least appreciated of vertebrates and are victims of many negative values and wrong ideas resulting from the direct interpretation of folklore. We try to demonstrate how these values and folklore can affect the way people relate to them and also the possible conservation impacts on these animals. Methods A questionnaire survey distributed to 514 people in the district of Évora, Portugal, was used to obtain data regarding the hypothesis that the existence of wrong ideas and negative values contributes to the phenomenon of human-associated persecution of these animals. A structural equation model was specified in order to confirm the hypothesis about the possible relationships between the presence of perceptions and negative values about amphibians and reptiles and persecution and anti-conservation attitudes. Sociodemographic variables were also added. Results The results of the model suggest that the presence of folklore and negative values clearly predicts persecution and anti-conservation attitudes towards amphibians and reptiles. Also, the existence of folklore varies sociodemographically, but negative values concerning these animals are widespread in the population. Conclusions With the use of structural equation models, this work is a contribution to the study of how certain ideas and values can directly influence human attitudes towards herpetofauna and how they can be a serious conservation issue. PMID:22316318

  17. Fish consumption, not fatty acid status, is related to quality of life in a healthy population

    NARCIS (Netherlands)

    Schiepers, Olga; De Groot, Renate; Jolles, Jelle; Van Boxtel, Martin

    2010-01-01

    Schiepers, O. J., De Groot, R. H. M., Jolles, J., & Van Boxtel, M. P. J. (2010). Fish consumption, not fatty acid status, is related to quality of life in a healthy population. Prostaglandins Leukot Essent Fatty Acids, 83(1), 31-35.

  18. Endoparasites in some Swedish Amphibians

    DEFF Research Database (Denmark)

    Cedhagen, Tomas

    1988-01-01

    A study was made of the endoparasites in specimens of Rana arvalis and R. temporaria collected on two occasions from a locality of southern Sweden. Some frogs were investigated directly after capture while other frogs were kept hibernating and the composition of the parasites as well...... as the behaviour of the parasites were studied after the termination of hibernation. Twelve species of parasites were found. Six of them, Polystoma integerrimum, Pleurogenes claviger (Trematoda), Rhabdias bufonis, Oswaldocruzia filiformis, Cosmocerca ornata and Oxysomatium brevicauda- tum (Nematoda), have...... not previously been reported from Sweden. The late Prof. O. Nybelin's unpublished records of parasites found in Swedish amphibians are also given....

  19. Helicobacter Pylori Associated Antral Gastritis in Peptic Ulcer Disease Patients and Normal Healthy Population of Kashmir, India

    OpenAIRE

    Gh. Jeelani Romshoo; G. M. Malik; M. Youssuf Bhat; Ab. Rashid rather; Javaid Ahmad Basu; Khursheed Ahmad Qureshi

    1998-01-01

    Aim: To study the association of Helicobacter pylori infection with chronic antral gastritis in peptic ulcer disease patients and healthy population of Kashmir. Methods: 50 peptic ulcer patients (duodenal ulcer = 46, gastric ulcer = 2 and combined duodenal and gastric ulcer = 2) and 30 asymptomatic healthy volunteers were included in this study. Peptic ulcer was diagnosed on endoscopic examination. 4–6 punch biopsies were taken from gastric antrum in all the individuals and in case of gastric...

  20. Phylogeny and differentiation of reptilian and amphibian ranaviruses detected in Europe.

    Science.gov (United States)

    Stöhr, Anke C; López-Bueno, Alberto; Blahak, Silvia; Caeiro, Maria F; Rosa, Gonçalo M; Alves de Matos, António Pedro; Martel, An; Alejo, Alí; Marschang, Rachel E

    2015-01-01

    Ranaviruses in amphibians and fish are considered emerging pathogens and several isolates have been extensively characterized in different studies. Ranaviruses have also been detected in reptiles with increasing frequency, but the role of reptilian hosts is still unclear and only limited sequence data has been provided. In this study, we characterized a number of ranaviruses detected in wild and captive animals in Europe based on sequence data from six genomic regions (major capsid protein (MCP), DNA polymerase (DNApol), ribonucleoside diphosphate reductase alpha and beta subunit-like proteins (RNR-α and -β), viral homolog of the alpha subunit of eukaryotic initiation factor 2, eIF-2α (vIF-2α) genes and microsatellite region). A total of ten different isolates from reptiles (tortoises, lizards, and a snake) and four ranaviruses from amphibians (anurans, urodeles) were included in the study. Furthermore, the complete genome sequences of three reptilian isolates were determined and a new PCR for rapid classification of the different variants of the genomic arrangement was developed. All ranaviruses showed slight variations on the partial nucleotide sequences from the different genomic regions (92.6-100%). Some very similar isolates could be distinguished by the size of the band from the microsatellite region. Three of the lizard isolates had a truncated vIF-2α gene; the other ranaviruses had full-length genes. In the phylogenetic analyses of concatenated sequences from different genes (3223 nt/10287 aa), the reptilian ranaviruses were often more closely related to amphibian ranaviruses than to each other, and most clustered together with previously detected ranaviruses from the same geographic region of origin. Comparative analyses show that among the closely related amphibian-like ranaviruses (ALRVs) described to date, three recently split and independently evolving distinct genetic groups can be distinguished. These findings underline the wide host range of

  1. Phylogeny and differentiation of reptilian and amphibian ranaviruses detected in Europe.

    Directory of Open Access Journals (Sweden)

    Anke C Stöhr

    Full Text Available Ranaviruses in amphibians and fish are considered emerging pathogens and several isolates have been extensively characterized in different studies. Ranaviruses have also been detected in reptiles with increasing frequency, but the role of reptilian hosts is still unclear and only limited sequence data has been provided. In this study, we characterized a number of ranaviruses detected in wild and captive animals in Europe based on sequence data from six genomic regions (major capsid protein (MCP, DNA polymerase (DNApol, ribonucleoside diphosphate reductase alpha and beta subunit-like proteins (RNR-α and -β, viral homolog of the alpha subunit of eukaryotic initiation factor 2, eIF-2α (vIF-2α genes and microsatellite region. A total of ten different isolates from reptiles (tortoises, lizards, and a snake and four ranaviruses from amphibians (anurans, urodeles were included in the study. Furthermore, the complete genome sequences of three reptilian isolates were determined and a new PCR for rapid classification of the different variants of the genomic arrangement was developed. All ranaviruses showed slight variations on the partial nucleotide sequences from the different genomic regions (92.6-100%. Some very similar isolates could be distinguished by the size of the band from the microsatellite region. Three of the lizard isolates had a truncated vIF-2α gene; the other ranaviruses had full-length genes. In the phylogenetic analyses of concatenated sequences from different genes (3223 nt/10287 aa, the reptilian ranaviruses were often more closely related to amphibian ranaviruses than to each other, and most clustered together with previously detected ranaviruses from the same geographic region of origin. Comparative analyses show that among the closely related amphibian-like ranaviruses (ALRVs described to date, three recently split and independently evolving distinct genetic groups can be distinguished. These findings underline the wide host

  2. Ranavirus-associated mass mortality in wild amphibians, the Netherlands, 2010: a first report.

    Science.gov (United States)

    Kik, Marja; Martel, An; Sluijs, Annemarieke Spitzen-van der; Pasmans, Frank; Wohlsein, Peter; Gröne, Andrea; Rijks, Jolianne M

    2011-11-01

    In 2010, a mass die-off of over 1000 wild water frogs (Pelophylax spp.) and at least 10 common newts (Lissotriton vulgaris) occurred in a pond in The Netherlands. Haemorrhagic disease with hepatomegaly and splenomegaly was evident. Microscopically, multiple organs presented cells with multifocal intracytoplasmic inclusion bodies, in which ranavirus-like particles were demonstrated ultrastructurally. All specimens examined tested positive for ranavirus by PCR. The sequence obtained showed a 100% identity with the one deposited for common midwife toad virus (CMTV). This is the first report of ranavirus-associated mortality in wild amphibian populations in The Netherlands. It is also the first time CMTV or a CMTV-like virus has been reported in these two species in the adult stage and outside of Spain. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Species Diversity and Distribution of Amphibians and Reptiles in Nature Park "Sinite Kamani" in Stara Planina Mt. (Bulgaria

    Directory of Open Access Journals (Sweden)

    Stanimira R. Deleva

    2014-12-01

    Full Text Available The current study presents briefly the species composition and distribution of the amphibians and reptiles in the Nature Park "Sinite Kamani" in Stara Planina Mnt. Bulgaria, based on a 2×2 km UTM grid. Between 2012 and 2014, we identified total 20 species (7 amphibians and 13 reptiles. We documented three new amphibian species for the region (Hyla arborea, Rana dalmatina and Rana graeca, which is discovered for the area for the first time and three species of reptiles (Testudo hermanni, Ablepharus kitaibelii and Lacerta trilienata. The contemporary conservation status for each species is presented and conservation threats and problems, specific for the park are discussed.

  4. Nasal carriage of Methicillin-resistant Staphylococcus aureus among healthy population of Kashmir, India

    Directory of Open Access Journals (Sweden)

    B A Fomda

    2014-01-01

    Full Text Available Background: Nasal colonisation with community acquired methicillin resistant Staphylococcus aureus (CA-MRSA is being increasingly reported, especially in places where people are in close contact and where hygiene is compromised. The aim of this study was to find out prevalence of methicillin resistant S.aureus (MRSA colonising anterior nares of healthy subjects. Materials and Methods: Nasal swabs of healthy subjects were collected aseptically and cultured using standard microbiological protocols. Antibiotic susceptibility was done by Kirby-Bauer disc diffusion method according to CLSI guidelines. Methicillin resistance was detected by cefoxitin disc diffusion method and confirmed by minimum inhibitory concentration (MIC and amplification of mecA gene by PCR. Strain typing of MRSA strains was done by PFGE. Results: Out of 820 samples, S.aureus was isolated from 229 (27.92% subjects. Of the 229 isolates, 15 were methicillin resistant. All S. aureus isolates were susceptible to vancomycin. Nasal carriage of MRSA was found to be 1.83% among healthy population. The isolates were found to be polyclonal by PFGE analysis. Conclusion: High prevalence of MRSA is a cause of concern and strategies to interrupt transmission should be implemented.

  5. Evaluación del estado de conservación de los anfibios en Chile Assessment of the conservation status of amphibians in Chile

    Directory of Open Access Journals (Sweden)

    HELEN DÍAZ-PÁEZ

    2003-09-01

    Full Text Available Los anfibios son uno de los grupos con mayores problemas de conservación en la actualidad. La declinación que se produce en numerosas poblaciones a nivel mundial ha llevado a los herpetólogos a reconocer la urgencia de abordar temas relacionados a la biología y estado de conservación de este grupo. En Chile existen numerosas propuestas para categorizar en estados de conservación, tanto a flora como fauna. De allí, que el estado de conservación de la fauna de anfibios haya sido evaluado a nivel nacional y regional. Sin embargo, la revisión de estos trabajos denota el uso reiterado de análisis cualitativos que carecen de datos cuantificables, estando sujetas a observaciones de campo y a la experiencia de los investigadores. Se hace necesario aplicar un método más cuantificable en la categorización de anfibios de manera que sea posible detectar y reconocer los factores que podrían incidir en la disminución de las poblaciones. El presente trabajo recopila la información disponible para los diversos taxa de anfibios chilenos, y evalúa el estado de conservación de la fauna de anfibios que habita en Chile por medio de la adición del índice SUMIN elaborado por Reca et al. (1994 y la propuesta por la Unión Internacional para la Conservación de la Naturaleza (IUCN 2001. Se comparan los resultados de la aplicación de estas metodologías con las evaluaciones previas.At present, amphibians are one of the groups with the most from conservation problems. The decline that is taking place in numerous amphibian populations around the world has led herpetologists to recognize the urgency of studying topics related to the biology and conservation status of this group. In Chile, numerous proposals exist to categorize the conservation status of flora as well as fauna at both national and regional levels. However, most of these works have used qualitative analysis. Because quantifiable data is not available, proposals of conservation status are

  6. Tempo of Diversification of Global Amphibians: One-Constant Rate, One-Continuous Shift or Multiple-Discrete Shifts?

    OpenAIRE

    Youhua Chen

    2014-01-01

    In this brief report, alternative time-varying diversification rate models were fitted onto the phylogeny of global amphibians by considering one-constant-rate (OCR), one-continuous-shift (OCS) and multiplediscrete- shifts (MDS) situations. The OCS diversification model was rejected by γ statistic (γ=-5.556, p⁄ 0.001), implying the existence of shifting diversification rates for global amphibian phylogeny. Through model selection, MDS diversification model outperformed OCS and OCR...

  7. [Effects and the associated factors of the 2016 China Motivational Healthy Walking Program among occupational population].

    Science.gov (United States)

    Jiang, W; Zhao, Y F; Yang, X Z; Li, Y C; Li, Z X; Wang, L H

    2018-05-06

    Objective: To examine the effects and associated factors of the China Motivational Healthy Walking Program among occupational population. Methods: The 2016 China Motivational Healthy Walking Program recruited 29 224 participants from 139 demonstration areas for comprehensive prevention and control of chronic and non-communicable disease at national level and 70 at provincial level. Intervention on walking was carried out by adopting group and individual motivating measures. Walking steps were recorded by electronic pedometer. We used percent of days achieving 10 000 steps (P10 000), percent of days fulfilling continuous walking (PCW), and proportion of valid walking (PVW) steps to reflect walking quantity, pattern and quality of participants. Motivation intensity was measured by summing up scores of each motivating activity. Questionnaire-based online survey collected information about demographic characteristics, lifestyle risk factors and chronic diseases. This study finally included 12 368 individuals in the analysis. Multilevel logistic regression model was used to assess the effect of group and individual motivating measures on walking activity and corresponding associated factors. Results: Age of the study sample was (41.2±8.99) years, and 58.17% (7 194) of them were female. After 100-day intervention, the P10 000, PCW and PVW of all participants were 93.89%±14.42%,92.01%±15.97% and 81.00%±7.45%, respectively. The mean P10 000 and PCW increased with rising group-motivated scores, self-motivated scores and individual-activity scores ( Pmotivated scores and self-motivated scores (both Pmotivated scores and self-motivated scores tended to have more likelihood of high-level of P10 000 and PCW. Age, sex, smoking status, education attainment and alcohol drinking were associated with P10 000 and PCW ( PMotivational Healthy Walking Program had positive effect on promoting healthy walking among occupational population. Group-motivated and self-motivated activities

  8. Salmonella Infections Caused by Reptiles and Amphibians in Childcare Centers

    Centers for Disease Control (CDC) Podcasts

    2013-02-07

    Dr. Neil Vora, an EIS Officer at CDC, discusses his article about Salmonella infections in childcare centers caused by reptiles and amphibians.  Created: 2/7/2013 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 2/7/2013.

  9. The role of 'atypical' Brucella in amphibians: are we facing novel emerging pathogens?

    Science.gov (United States)

    Mühldorfer, K; Wibbelt, G; Szentiks, C A; Fischer, D; Scholz, H C; Zschöck, M; Eisenberg, T

    2017-01-01

    To discuss together the novel cases of Brucella infections in frogs with the results of published reports to extend our current knowledge on 'atypical' brucellae isolated from amphibians and to discuss the challenges we face on this extraordinary emerging group of pathogens. Since our first description, an additional 14 isolates from four different frog species were collected. Novel isolates and a subset of Brucella isolates previously cultured from African bullfrogs were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), Fourier transform-infrared (FT-IR) spectroscopy and broth microdilution susceptibility testing. MALDI-TOF MS worked very efficiently for an accurate bacterial identification to the genus level. Within the cluster analysis, 'atypical' brucellae grouped distant from Brucella melitensis and were even more separated by FT-IR spectroscopy with respect to their geographical origin. Minimum inhibitory concentrations of 14 antimicrobial substances are provided as baseline data on antimicrobial susceptibility. The case history of Brucella infections in amphibians reveals a variety of pathologies ranging from localized manifestations to systemic infections. Some isolates seem to be capable of causing high mortality in zoological exhibitions putting higher demands on the management of endangered frog species. There is considerable risk in overlooking and misidentifying 'atypical' Brucella in routine diagnostics. Brucella have only recently been described in cold-blooded vertebrates. Their presence in frog species native to Africa, America and Australia indicates a more common occurrence in amphibians than previously thought. This study provides an extensive overview of amphibian brucellae by highlighting the main features of their clinical significance, diagnosis and zoonotic potential. © 2016 The Society for Applied Microbiology.

  10. Engineering a future for amphibians under a changing climate

    Science.gov (United States)

    Noreen Parks; Deanna H. Olson

    2011-01-01

    Climate variation exacerbates threats to amphibians such as disease and habitat loss. Yet, by and large existing species- and land-management plans give little if any consideration to climate impacts. Moreover, many management actions that do address emerging climate patterns have yet to be evaluated for feasibility and effectiveness. To help address these needs,...

  11. Eco–geographical characterization of aquatic microhabitats used by amphibians in the Mediterranean Basin

    Directory of Open Access Journals (Sweden)

    Benítez, M.

    2017-01-01

    Full Text Available Small freshwater ecosystems, whether natural or artificial origin, are aquatic microhabitats for many species and are particularly important in the Mediterranean region. This study characterizes the aquatic microhabitats suitable for amphibian reproduction in the Andalusian Mediterranean Basin and identifies the environmental and geographical features that determine the presence of different amphibian species in these water bodies. Geographical and environmental favourability models were performed to determine the relationship between characteristics of the microhabitats and species presence. The characteristics analysed were geographical location, external environment (climate and topography, surrounding conditions (connectivity and conservation, type of water body, water conditions, and water dimensions. Microhabitats located in the western and central part of the study area were geographically favourable for most species. In descending order, the most common environmental factors characterizing the microhabitats were typology, surrounding conditions, water condition, external environment and size of the water body. The most common variables in the models were the connectivity between water bodies and old wells, a frequent type of microhabitat in areas of traditional cultures. Management plans should take these results into account in efforts to preserve these habitats for wildlife and especially amphibians.

  12. Evolutionary insights into the regulation of courtship behavior in male amphibians and reptiles.

    Science.gov (United States)

    Woolley, Sarah C; Sakata, Jon T; Crews, David

    2004-11-15

    Comparative studies of species differences and similarities in the regulation of courtship behavior afford an understanding of evolutionary pressures and constraints shaping reproductive processes and the relative contributions of hormonal, genetic, and ecological factors. Here, we review species differences and similarities in the control of courtship and copulatory behaviors in male amphibians and reptiles, focusing on the role of sex steroid hormones, the neurohormone arginine vasotocin (AVT), and catecholamines. We discuss species differences in the sensory modalities used during courtship and in the neural correlates of these differences, as well as the value of particular model systems for neural evolution studies with regard to reproductive processes. For example, in some genera of amphibians (e.g., Ambystoma) and reptiles (e.g., Cnemidophorus), interspecific hybridizations occur, making it possible to compare the ancestral with the descendant species, and these systems provide a window into the process of behavioral and neural evolution as well as the effect of genome size. Though our understanding of the hormonal and neural correlates of mating behavior in a variety of amphibian and reptilian species has advanced substantially, more studies that manipulate hormone or neurotransmitter systems are required to assess the functions of these systems.

  13. Assessing DNA Barcodes for Species Identification in North American Reptiles and Amphibians in Natural History Collections.

    Science.gov (United States)

    Chambers, E Anne; Hebert, Paul D N

    2016-01-01

    High rates of species discovery and loss have led to the urgent need for more rapid assessment of species diversity in the herpetofauna. DNA barcoding allows for the preliminary identification of species based on sequence divergence. Prior DNA barcoding work on reptiles and amphibians has revealed higher biodiversity counts than previously estimated due to cases of cryptic and undiscovered species. Past studies have provided DNA barcodes for just 14% of the North American herpetofauna, revealing the need for expanded coverage. This study extends the DNA barcode reference library for North American herpetofauna, assesses the utility of this approach in aiding species delimitation, and examines the correspondence between current species boundaries and sequence clusters designated by the BIN system. Sequences were obtained from 730 specimens, representing 274 species (43%) from the North American herpetofauna. Mean intraspecific divergences were 1% and 3%, while average congeneric sequence divergences were 16% and 14% in amphibians and reptiles, respectively. BIN assignments corresponded with current species boundaries in 79% of amphibians, 100% of turtles, and 60% of squamates. Deep divergences (>2%) were noted in 35% of squamate and 16% of amphibian species, and low divergences (reptiles and 23% of amphibians, patterns reflected in BIN assignments. Sequence recovery declined with specimen age, and variation in recovery success was noted among collections. Within collections, barcodes effectively flagged seven mislabeled tissues, and barcode fragments were recovered from five formalin-fixed specimens. This study demonstrates that DNA barcodes can effectively flag errors in museum collections, while BIN splits and merges reveal taxa belonging to deeply diverged or hybridizing lineages. This study is the first effort to compile a reference library of DNA barcodes for herpetofauna on a continental scale.

  14. Applications of geographic information systems and remote sensing techniques to conservation of amphibians in northwestern Ecuador

    Directory of Open Access Journals (Sweden)

    Mariela Palacios González

    2015-01-01

    Full Text Available The biodiversity of the Andean Chocó in western Ecuador and Colombia is threatened by anthropogenic changes in land cover. The main goal of this study was to contribute to conservation of 12 threatened species of amphibians at a cloud forest site in northwestern Ecuador, by identifying and proposing protection of critical areas. We used Geographic Information Systems (GIS and remote sensing techniques to quantify land cover changes over 35 years and outline important areas for amphibian conservation. We performed a supervised classification of an IKONOS satellite image from 2011 and two aerial photographs from 1977 and 2000. The 2011 IKONOS satellite image classification was used to delineate areas important for conservation of threatened amphibians within a 200 m buffer around rivers and streams. The overall classification accuracy of the three images was ≥80%. Forest cover was reduced by 17% during the last 34 years. However, only 50% of the study area retained the initial (1977 forest cover, as land was cleared for farming and eventually reforested. Finally, using the 2011 IKONOS satellite image, we delineated areas of potential conservation interest that would benefit the long term survival of threatened amphibian species at the Ecuadorian cloud forest site studied.

  15. Widespread presence of the pathogenic fungus Batrachochytrium dendrobatidis in wild amphibian communities in Madagascar

    Science.gov (United States)

    Bletz, Molly C.; Rosa, Gonçalo M.; Andreone, Franco; Courtois, Elodie A.; Schmeller, Dirk S.; Rabibisoa, Nirhy H. C.; Rabemananjara, Falitiana C. E.; Raharivololoniaina, Liliane; Vences, Miguel; Weldon, Ché; Edmonds, Devin; Raxworthy, Christopher J.; Harris, Reid N.; Fisher, Matthew C.; Crottini, Angelica

    2015-01-01

    Amphibian chytridiomycosis, an emerging infectious disease caused by the fungus Batrachochytrium dendrobatidis (Bd), has been a significant driver of amphibian declines. While globally widespread, Bd had not yet been reported from within Madagascar. We document surveys conducted across the country between 2005 and 2014, showing Bd's first record in 2010. Subsequently, Bd was detected in multiple areas, with prevalence reaching up to 100%. Detection of Bd appears to be associated with mid to high elevation sites and to have a seasonal pattern, with greater detectability during the dry season. Lineage-based PCR was performed on a subset of samples. While some did not amplify with any lineage probe, when a positive signal was observed, samples were most similar to the Global Panzootic Lineage (BdGPL). These results may suggest that Bd arrived recently, but do not exclude the existence of a previously undetected endemic Bd genotype. Representatives of all native anuran families have tested Bd-positive, and exposure trials confirm infection by Bd is possible. Bd's presence could pose significant threats to Madagascar's unique “megadiverse” amphibians. PMID:25719857

  16. Amphibians of Serra Bonita, southern Bahia: a new hotpoint within Brazil's Atlantic Forest hotspot.

    Science.gov (United States)

    Dias, Iuri Ribeiro; Medeiros, Tadeu Teixeira; Vila Nova, Marcos Ferreira; Solé, Mirco

    2014-01-01

    We studied the amphibian community of the Private Reserve of Natural Heritage (RPPN) Serra Bonita, an area of 20 km(2) with steep altitudinal gradients (200-950 m a.s.l.) located in the municipalities of Camacan and Pau-Brasil, southern Bahia State, Brazil. Data were obtained at 38 sampling sites (including ponds and transects within the forest and in streams), through active and visual and acoustic searches, pitfall traps, and opportunistic encounters. We recorded 80 amphibian species distributed in 15 families: Aromobatidae (1), Brachycephalidae (3), Bufonidae (4), Centrolenidae (2), Ceratophryidae (1), Craugastoridae (7), Eleutherodactylidae (2), Hemiphractidae (2), Hylidae (42), Hylodidae (1), Leptodactylidae (7), Microhylidae (3), Siphonopidae (1), Odontophrynidae (3) and Pipidae (1). Species richness was positively correlated with monthly rainfall. Near 36% of the species were found in strictly forest environments, 15% are endemic to Bahia State and 77.2% are endemic to the Atlantic Forest biome. The large species diversity of this small area, the high degree of endemism and the taxonomic and biogeographic significance turn the Serra Bonita mountain into a hotpoint for amphibians within Brazil's Atlantic Forest hotspot.

  17. Preliminary checklist of amphibians and reptiles from Baramita, Guyana

    Science.gov (United States)

    Reynolds, R.P.; MacCulloch, R.D.

    2012-01-01

    We provide an initial checklist of the herpetofauna of Baramita, a lowland rainforest site in the Northwest Region of Guyana. Twenty-five amphibian and 28 reptile species were collected during two separate dry-season visits. New country records for two species of snakes are documented, contributing to the knowledge on the incompletely known herpetofauna of Guyana.

  18. Comparative and phylogenetic perspectives of the cleavage process in tailed amphibians.

    Science.gov (United States)

    Desnitskiy, Alexey G; Litvinchuk, Spartak N

    2015-10-01

    The order Caudata includes about 660 species and displays a variety of important developmental traits such as cleavage pattern and egg size. However, the cleavage process of tailed amphibians has never been analyzed within a phylogenetic framework. We use published data on the embryos of 36 species concerning the character of the third cleavage furrow (latitudinal, longitudinal or variable) and the magnitude of synchronous cleavage period (up to 3-4 synchronous cell divisions in the animal hemisphere or a considerably longer series of synchronous divisions followed by midblastula transition). Several species from basal caudate families Cryptobranchidae (Andrias davidianus and Cryptobranchus alleganiensis) and Hynobiidae (Onychodactylus japonicus) as well as several representatives from derived families Plethodontidae (Desmognathus fuscus and Ensatina eschscholtzii) and Proteidae (Necturus maculosus) are characterized by longitudinal furrows of the third cleavage and the loss of synchrony as early as the 8-cell stage. By contrast, many representatives of derived families Ambystomatidae and Salamandridae have latitudinal furrows of the third cleavage and extensive period of synchronous divisions. Our analysis of these ontogenetic characters mapped onto a phylogenetic tree shows that the cleavage pattern of large, yolky eggs with short series of synchronous divisions is an ancestral trait for the tailed amphibians, while the data on the orientation of third cleavage furrows seem to be ambiguous with respect to phylogeny. Nevertheless, the midblastula transition, which is characteristic of the model species Ambystoma mexicanum (Caudata) and Xenopus laevis (Anura), might have evolved convergently in these two amphibian orders.

  19. Development of a Standardized Approach for Assessing Potential Risks to Amphibians Exposed to Sediment and Hydric Soils

    Science.gov (United States)

    2004-05-01

    different foods in amphibian tests. Possible foods considered for this study included boiled spinach, boiled lettuce , fish flakes, TetraMin...other foods such as boiled spinach or lettuce . • Sediment tests in flow-through chambers are preferable over static-renewal systems because of... hybridization may be possible. Amphibian Ecological Risk Assessment Guidance Manual Q:\\mw97\\Projects\\9070045\\419\\Appendix C\\appC-1

  20. Origin of amphibian and avian chromosomes by fission, fusion, and retention of ancestral chromosomes

    Science.gov (United States)

    Voss, Stephen R.; Kump, D. Kevin; Putta, Srikrishna; Pauly, Nathan; Reynolds, Anna; Henry, Rema J.; Basa, Saritha; Walker, John A.; Smith, Jeramiah J.

    2011-01-01

    Amphibian genomes differ greatly in DNA content and chromosome size, morphology, and number. Investigations of this diversity are needed to identify mechanisms that have shaped the evolution of vertebrate genomes. We used comparative mapping to investigate the organization of genes in the Mexican axolotl (Ambystoma mexicanum), a species that presents relatively few chromosomes (n = 14) and a gigantic genome (>20 pg/N). We show extensive conservation of synteny between Ambystoma, chicken, and human, and a positive correlation between the length of conserved segments and genome size. Ambystoma segments are estimated to be four to 51 times longer than homologous human and chicken segments. Strikingly, genes demarking the structures of 28 chicken chromosomes are ordered among linkage groups defining the Ambystoma genome, and we show that these same chromosomal segments are also conserved in a distantly related anuran amphibian (Xenopus tropicalis). Using linkage relationships from the amphibian maps, we predict that three chicken chromosomes originated by fusion, nine to 14 originated by fission, and 12–17 evolved directly from ancestral tetrapod chromosomes. We further show that some ancestral segments were fused prior to the divergence of salamanders and anurans, while others fused independently and randomly as chromosome numbers were reduced in lineages leading to Ambystoma and Xenopus. The maintenance of gene order relationships between chromosomal segments that have greatly expanded and contracted in salamander and chicken genomes, respectively, suggests selection to maintain synteny relationships and/or extremely low rates of chromosomal rearrangement. Overall, the results demonstrate the value of data from diverse, amphibian genomes in studies of vertebrate genome evolution. PMID:21482624