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Sample records for ranid frogs collected

  1. Endemic ranid (Amphibia: Anura) genera in southern mountain ranges of the Indian subcontinent represent ancient frog lineages: evidence from molecular data.

    Science.gov (United States)

    Roelants, Kim; Jiang, Jianping; Bossuyt, Franky

    2004-05-01

    The geological history of the Indian subcontinent is marked by successive episodes of extensive isolation, which have provided ideal settings for the development of a unique floral and faunal diversity. By molecular phylogenetic analysis of a large set of ranid frog taxa from the Oriental realm, we show that four genera, now restricted to torrential habitats in the Western Ghats of India and the central highlands of Sri Lanka, represent remnants of ancient divergences. None of three other biodiversity hotspots in the Oriental mainland were found to harbour an equivalent level of long-term evolutionary history in this frog group. By unceasingly providing favourable humid conditions, the subcontinent's southern mountain ranges have served as refugia for old lineages, and hence constitute a unique reservoir of ancient ranid endemism.

  2. INTRAERYTHROCYTIC DEVELOPMENT OF SPECIES OF HEPATOZOON INFECTING RANID FROGS: EVIDENCE FOR CONVERGENCE OF LIFE CYCLE CHARACTERISTICS AMONG APICOMPLEXANS

    National Research Council Canada - National Science Library

    Todd G. Smith; Betty Kim; Henry Hong; Sherwin S. Desser

    2000-01-01

    Intraerythrocytic development of the adeleorin apicomplexans Hepatozoon clamatae and Hepatozoon catesbianae were investigated in the bullfrog, Rana catesbeiana, the green frog, Rana clamitans melanota...

  3. Vicariance and Its Impact on the Molecular Ecology of a Chinese Ranid Frog Species-Complex (Odorrana schmackeri, Ranidae.

    Directory of Open Access Journals (Sweden)

    Yongmin Li

    Full Text Available Paleogeological events and Pleistocene climatic fluctuations have had profound influences on the genetic patterns and phylogeographic structure of species in southern China. In this study, we investigated the population genetic structure and Phylogeography of the Odorrana schmackeri species complex, mountain stream-dwelling odorous frogs, endemic to southern China. We obtained mitochondrial sequences (1,151bp of the complete ND2 gene and two flanking tRNAs of 511 individuals from 25 sites for phylogeographic analyses. Phylogenetic reconstruction revealed seven divergent evolutionary lineages, with mean pairwise (K2P sequence distances from 7.8% to 21.1%, except for a closer ND2 distance (3.4%. The complex geological history of southern China drove matrilineal divergence in the O. schmackeri species complex into highly structured geographical units. The first divergence between lineage A+B and other lineages (C-G had likely been influenced by the uplift of coastal mountains of Southeast China during the Mio-Pliocene period. The subsequent divergences between the lineages C-G may have followed the formation of the Three Gorges and the intensification of the East Asian summer monsoon during the late Pliocene and early Pleistocene. Demographic analyses indicated that major lineages A and C have been experienced recent population expansion (c. 0.045-0.245 Ma from multiple refugia prior to the Last Glacial Maximum (LGM. Molecular analysis suggest that these seven lineages may represent seven different species, three described species and four cryptic species and should at least be separated into seven management units corresponding to these seven geographic lineages for conservation.

  4. Selection, trans-species polymorphism, and locus identification of major histocompatibility complex class IIβ alleles of New World ranid frogs

    Science.gov (United States)

    Kiemnec-Tyburczy, Karen M.; Richmond, Jonathan Q.; Savage, Anna E.; Zamudio, Kelly R.

    2010-01-01

    Genes encoded by the major histocompatibility complex (MHC) play key roles in the vertebrate immune system. However, our understanding of the evolutionary processes and underlying genetic mechanisms shaping these genes is limited in many taxa, including amphibians, a group currently impacted by emerging infectious diseases. To further elucidate the evolution of the MHC in frogs (anurans) and develop tools for population genetics, we surveyed allelic diversity of the MHC class II ??1 domain in both genomic and complementary DNA of seven New World species in the genus Rana (Lithobates). To assign locus affiliation to our alleles, we used a "gene walking" technique to obtain intron 2 sequences that flanked MHC class II?? exon 2. Two distinct intron sequences were recovered, suggesting the presence of at least two class II?? loci in Rana. We designed a primer pair that successfully amplified an orthologous locus from all seven Rana species. In total, we recovered 13 alleles and documented trans-species polymorphism for four of the alleles. We also found quantitative evidence of selection acting on amino acid residues that are putatively involved in peptide binding and structural stability of the ??1 domain of anurans. Our results indicated that primer mismatch can result in polymerase chain reaction (PCR) bias, which influences the number of alleles that are recovered. Using a single locus may minimize PCR bias caused by primer mismatch, and the gene walking technique was an effective approach for generating single-copy orthologous markers necessary for future studies of MHC allelic variation in natural amphibian populations. ?? 2010 Springer-Verlag.

  5. Surveys for presence of Oregon spotted frog (Rana pretiosa): background information and field methods

    Science.gov (United States)

    Pearl, Christopher A.; Clayton, David; Turner, Lauri

    2010-01-01

    The Oregon spotted frog (Rana pretiosa) is the most aquatic of the native frogs in the Pacific Northwest. The common name derives from the pattern of black, ragged-edged spots set against a brown or red ground color on the dorsum of adult frogs. Oregon spotted frogs are generally associated with wetland complexes that have several aquatic habitat types and sizeable coverage of emergent vegetation. Like other ranid frogs native to the Northwest, Oregon spotted frogs breed in spring, larvae transform in summer of their breeding year, and adults tend to be relatively short lived (3-5 yrs). Each life stage (egg, tadpole, juvenile and adult) has characteristics that present challenges for detection. Breeding can be explosive and completed within 1-2 weeks. Egg masses are laid in aggregations, often in a few locations in large areas of potential habitat. Egg masses can develop, hatch, and disintegrate in difficult to identify, have low survival, and spend most of their 3-4 months hidden in vegetation or flocculant substrates. Juveniles and adults are often difficult to capture and can spend summers away from breeding areas. Moreover, a substantial portion of extant populations are of limited size (Management (BLM) personnel tasked with surveying for the presence of Oregon spotted frogs. Our objective was to summarize information to improve the efficiency of field surveys and increase chances of detection if frogs are present. We include overviews of historical and extant ranges of Oregon spotted frog. We briefly summarize what is known of Oregon spotted frog habitat associations and review aspects of behavior and ecology that are likely to affect detectability in the field. We summarize characteristics that can help differentiate Oregon spotted frog life stages from other northwestern ranid frogs encountered during surveys. Appendices include examples of data collection formats and a protocol for disinfecting field gear.

  6. Frog eat frog: exploring variables influencing anurophagy

    Directory of Open Access Journals (Sweden)

    G. John Measey

    2015-08-01

    Full Text Available Background. Frogs are generalist predators of a wide range of typically small prey items. But descriptions of dietary items regularly include other anurans, such that frogs are considered to be among the most important of anuran predators. However, the only existing hypothesis for the inclusion of anurans in the diet of post-metamorphic frogs postulates that it happens more often in bigger frogs. Moreover, this hypothesis has yet to be tested.Methods. We reviewed the literature on frog diet in order to test the size hypothesis and determine whether there are other putative explanations for anurans in the diet of post-metamorphic frogs. In addition to size, we recorded the habitat, the number of other sympatric anuran species, and whether or not the population was invasive. We controlled for taxonomic bias by including the superfamily in our analysis.Results. Around one fifth of the 355 records included anurans as dietary items of populations studied, suggesting that frogs eating anurans is not unusual. Our data showed a clear taxonomic bias with ranids and pipids having a higher proportion of anuran prey than other superfamilies. Accounting for this taxonomic bias, we found that size in addition to being invasive, local anuran diversity, and habitat produced a model that best fitted our data. Large invasive frogs that live in forests with high anuran diversity are most likely to have a higher proportion of anurans in their diet.Conclusions. We confirm the validity of the size hypothesis for anurophagy, but show that there are additional significant variables. The circumstances under which frogs eat frogs are likely to be complex, but our data may help to alert conservationists to the possible dangers of invading frogs entering areas with threatened anuran species.

  7. Indirect effects of introduced trout on Cascades frogs (Rana cascadae) via shared aquatic prey

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    Maxwell B. Joseph; Jonah Piovia-Scott; Sharon P. Lawler; Karen L. Pope

    2010-01-01

    1. The introduction of trout to montane lakes has negatively affected amphibian populations across the western United States. In northern California’s Klamath–Siskiyou Mountains, introduced trout have diminished the distribution and abundance of a native ranid frog, Rana (=Lithobates)

  8. Flow cytometry used to assess genetic damage in frogs from farm ponds

    Science.gov (United States)

    Bly, B.L.; Knutson, M.G.; Sandheinrich, M.B.; Gray, B.R.; Jobe, D.A.

    2004-01-01

    Flow cytometry (FC) is a laboratory method used to detect genetic damage induced by environmental contaminants and other stressors in animals, including amphibians. We tested FC methods on three species of ranid frogs collected from farm ponds and natural wetlands in southeastern Minnesota. We compared FC metrics for Rana clamitans between ponds with direct exposure to agricultural contaminants and reference (unexposed) ponds. Concentrations of atrazine in water from our farm ponds ranged from 0.04 to 0.55 ppb. We found that R. clamitans from exposed ponds had DNA content similar to frogs from unexposed ponds. Pond-averaged C-values (a measure of DNA content) ranged from 6.53 to 7.08 for R. pipiens (n . 13), 6.55 to 6.60 for R. clamitans (n . 40) and 6.74 for R. palustris (n . 5). Among all species, the mean sample CVs ranged from 1.91 (R. palustris) to 6.31 (R. pipiens). Deformities were observed in only 2 of 796 individuals among all species and occurred in both reference and exposed ponds. Although we did not detect evidence of DNA damage associated with agriculture in our study, we demonstrated the potential of FC for screening amphibian populations for genetic damage. Metrics from a variety of amphibian species and locations as well as laboratory studies are needed to further assess the value of FC for monitoring amphibian genetic integrity in contaminated sites.

  9. Transient “deafness” accompanies auditory development during metamorphosis from tadpole to frog

    OpenAIRE

    Boatright-Horowitz, Seth S.; Simmons, Andrea Megela

    1997-01-01

    During metamorphosis, ranid frogs shift from a purely aquatic to a partly terrestrial lifestyle. The central auditory system undergoes functional and neuroanatomical reorganization in parallel with the development of new sound conduction pathways adapted for the detection of airborne sounds. Neural responses to sounds can be recorded from the auditory midbrain of tadpoles shortly after hatching, with higher rates of synchronous neural activity and lower sharpness of tuning than observed in po...

  10. Spatio-Temporal Dynamics in Collective Frog Choruses Examined by Mathematical Modeling and Field Observations

    Science.gov (United States)

    Aihara, Ikkyu; Mizumoto, Takeshi; Otsuka, Takuma; Awano, Hiromitsu; Nagira, Kohei; Okuno, Hiroshi G.; Aihara, Kazuyuki

    2014-01-01

    This paper reports theoretical and experimental studies on spatio-temporal dynamics in the choruses of male Japanese tree frogs. First, we theoretically model their calling times and positions as a system of coupled mobile oscillators. Numerical simulation of the model as well as calculation of the order parameters show that the spatio-temporal dynamics exhibits bistability between two-cluster antisynchronization and wavy antisynchronization, by assuming that the frogs are attracted to the edge of a simple circular breeding site. Second, we change the shape of the breeding site from the circle to rectangles including a straight line, and evaluate the stability of two-cluster and wavy antisynchronization. Numerical simulation shows that two-cluster antisynchronization is more frequently observed than wavy antisynchronization. Finally, we recorded frog choruses at an actual paddy field using our sound-imaging method. Analysis of the video demonstrated a consistent result with the aforementioned simulation: namely, two-cluster antisynchronization was more frequently realized.

  11. Evaluation of the skin peptide defenses of the Oregon spotted frog Rana pretiosa against infection by the chytrid fungus Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Conlon, J Michael; Reinert, Laura K; Mechkarska, Milena; Prajeep, Manju; Meetani, Mohammed A; Coquet, Laurent; Jouenne, Thierry; Hayes, Marc P; Padgett-Flohr, Gretchen; Rollins-Smith, Louise A

    2013-06-01

    Population declines due to amphibian chytridiomycosis among selected species of ranid frogs from western North America have been severe, but there is evidence that the Oregon spotted frog, Rana pretiosa Baird and Girard, 1853, displays resistance to the disease. Norepinephrine-stimulated skin secretions were collected from a non-declining population of R. pretiosa that had been exposed to the causative agent Batrachochytrium dendrobatidis. Peptidomic analysis led to identification and isolation, in pure form, of a total of 18 host-defense peptides that were characterized structurally. Brevinin-1PRa, -1PRb, -1PRc, and -1PRd, esculentin-2PRa and -PRb, ranatuerin-2PRa, -2PRb, -2PRc, and -2PRe, temporin-PRb and -PRc were identified in an earlier study of skin secretions of frogs from a different population of R. pretiosa known to be declining. Ranatuerin-2PRf, -2PRg, -2PRh, temporin-PRd, -PRe, and -PRf were not identified in skin secretions from frogs from the declining population, whereas temporin-PRa and ranatuerin-2PRd, present in skin secretions from the declining population, were not detected in the current study. All purified peptides inhibited the growth of B. dendrobatidis zoospores. Peptides of the brevinin-1 and esculentin-2 families displayed the highest potency (minimum inhibitory concentration = 6.25-12.5 μM). The study provides support for the hypothesis that the multiplicity and diversity of the antimicrobial peptide repertoire in R. pretiosa and the high growth-inhibitory potency of certain peptides against B. dendrobatidis are important in conferring a measure of resistance to fatal chytridiomycosis.

  12. Assembly of the eastern North American herpetofauna: new evidence from lizards and frogs.

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    Macey, J Robert; Schulte, James A; Strasburg, Jared L; Brisson, Jennifer A; Larson, Allan; Ananjeva, Natalia B; Wang, Yuezhao; Parham, James F; Papenfuss, Theodore J

    2006-09-22

    Darwin first recognized the importance of episodic intercontinental dispersal in the establishment of worldwide biotic diversity. Faunal exchange across the Bering Land Bridge is a major example of such dispersal. Here, we demonstrate with mitochondrial DNA evidence that three independent dispersal events from Asia to North America are the source for almost all lizard taxa found in continental eastern North America. Two other dispersal events across Beringia account for observed diversity among North American ranid frogs, one of the most species-rich groups of frogs in eastern North America. The contribution of faunal elements from Asia via dispersal across Beringia is a dominant theme in the historical assembly of the eastern North American herpetofauna.

  13. Region 6 Northern Leopard Frog Information

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document contains a collection of completed questionnaires and related additional data regarding the status review of the northern leopard frog. On July 1,...

  14. Amolopkinins W1 and W2--novel bradykinin-related peptides (BRPs) from the skin of the Chinese torrent frog, Amolops wuyiensis: antagonists of bradykinin-induced smooth muscle contraction of the rat ileum.

    Science.gov (United States)

    Zhou, Xiaowei; Wang, Lei; Zhou, Mei; Chen, Tianbao; Ding, Anwei; Rao, Pingfan; Walker, Brian; Shaw, Chris

    2009-05-01

    Bradykinin-related peptides (BRPs) represent one of the most widespread and closely studied families of amphibian defensive skin secretion peptides. Apart from canonical bradykinin (RPPGFSPFR) that was first reported in skin extracts of the European brown frog, Rana temporaria, many additional site-substituted, N- and/or C-terminally extended peptides have been isolated from skin extracts and secretions from representative species of the families Ranidae, Hylidae, Bombinatoridae and Leiopelmatidae. The most diverse range of BRPs has been found in ranid frog skin secretions and this probably reflects the diversity and number of species studied and their associated life histories within this taxon. Amolops (torrent or cascade frogs) is a genus within the Ranidae that has been poorly studied. Here we report the presence of two novel BRPs in the skin secretions of the Chinese Wuyi Mountain torrent frog (Amolops wuyiensis). Amolopkinins W1 and W2 are dodecapeptides differing in only one amino acid residue at position 2 (Val/Ala) that are essentially (Leu(1), Thr(6))-bradykinins extended at the N-terminus by either RVAL (W1) or RAAL (W2). Amolopkinins W1 and W2 are structurally similar to amolopkinin L1 from Amolops loloensis and the major BRP (Leu(1), Thr(6), Trp(8))-bradykinin from the skin of the Japanese frog, Rana sakuraii. A. wuyiensis amolopkinins were separately encoded as single copies within discrete precursors of 61 amino acid residues as deduced from cloned skin cDNA. Synthetic replicates of both peptides were found to potently antagonize the contractile effects of canonical bradykinin on isolated rat ileum smooth muscle preparations. Amolopkinins thus appear to represent a novel sub-family of ranid frog skin secretion BRPs.

  15. Batrachochytrium dendrobatidis and the Decline and Survival of the Relict Leopard Frog.

    Science.gov (United States)

    Jaeger, Jef R; Waddle, Anthony W; Rivera, Rebeca; Harrison, D Tyler; Ellison, Silas; Forrest, Matthew J; Vredenburg, Vance T; van Breukelen, Frank

    2017-06-01

    Epizootic disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd) is a major driver of amphibian declines, yet many amphibians declined before the pathogen was described. The Relict Leopard Frog, Rana onca (=Lithobates onca), was nearly extinct, with the exception of populations within a few geothermal springs. Growth of Bd, however, is limited by high water temperature, and geothermal springs may have provided refuge during outbreaks of chytridiomycosis. We conducted field surveys and laboratory experiments to assess the susceptibility of R. onca to Bd. In the field, we found Bd at one of the two areas where remnant populations of R. onca still occur, but not in the other. In the laboratory, we infected juvenile frogs from these two areas with two hypervirulent Bd isolates associated with declines in other ranid species. In our experiments, these Bd isolates did not affect survivorship of R. onca and most infections (64%) were cleared by the end of the experiments. We propose that R. onca either has inherent resistance to Bd or has recently evolved such resistance. These results may be important for conservation efforts aimed at establishing new populations of R. onca across a landscape where Bd exists. Resistance, however, varies among life stages, and we also did not assess Bd from the local environment. We caution that the resistance we observed for young frogs under laboratory conditions may not translate to the situation for R. onca in the wild.

  16. Copper and nickel effects on survival and growth of northern leopard frog (Lithobates pipiens) tadpoles in field-collected smelting effluent water.

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    Leduc, Joël; Echaubard, Pierre; Trudeau, Vance; Lesbarrères, David

    2016-03-01

    Trace metals can have subtle yet chronic impacts on organisms by inducing physiological stress that reduces their survival or impedes their ability to tolerate additional environmental stressors. The toxicity literature indicates, however, that aquatic organisms react differently to trace metals depending on the environments in which they reside. The objective of the present study was to understand the response of northern leopard frog (Lithobates pipiens) larvae to ionic copper (Cu), nickel (Ni), and their combination within an effluent water collected downstream of a tailings wetland area. Tadpoles were assigned randomly to 1 of 8 Cu concentrations (8-200 μg/L), 7 Ni concentrations (160-1200 μg/L), or 8 Cu and Ni combined concentrations (8:160-200:1200 μg/L) and showed significant differences in survival and life history traits among treatments. In the Cu and Cu and Ni combined treatments, tadpole survival decreased with increased Cu exposure starting at Cu = 160 μg/L and in the Ni treatment, tadpole survival decreased with increased Ni exposure starting at Ni = 650 μg/L. All Cu-exposed treatments induced a growth increase as the concentration increased, whereas the tadpoles showed a significant decrease in growth rate in Ni treatments. These contrasting outcomes suggest a plastic response to trace metals whereby tadpoles allocate energy reserves toward either escaping or coping with stress. Finally, the authors' argue that future studies will benefit from examining the impacts of multiple stressors in aquatic ecosystems to provide better environmental mitigation. © 2015 SETAC.

  17. Convergent evolution of chemical defense in poison frogs and arthropod prey between Madagascar and the Neotropics

    OpenAIRE

    Clark, Valerie C.; Christopher J Raxworthy; Rakotomalala, Valérie; Sierwald, Petra; Fisher, Brian L.

    2005-01-01

    With few exceptions, aposematically colored poison frogs sequester defensive alkaloids, unchanged, from dietary arthropods. In the Neotropics, myrmicine and formicine ants and the siphonotid millipede Rhinotus purpureus are dietary sources for alkaloids in dendrobatid poison frogs, yet the arthropod sources for Mantella poison frogs in Madagascar remained unknown. We report GC-MS analyses of extracts of arthropods and microsympatric Malagasy poison frogs (Mantella) collected from Ranomafana, ...

  18. Paracosmocercella rosettae n. gen. et n. sp. (Nematoda: Cosmocercoidea: Cosmocercidae) collected from the Japanese tree frog, Hyla japonica (Anura: Hylidae), in Japan.

    Science.gov (United States)

    Hasegawa, Hideo; Ikeda, Yatsukaho

    2007-08-01

    A new genus, Paracosmocercella (Nematoda: Cosmocercoidea: Cosmocercidae), is proposed with monotypic Paracosmocercella rosettae n. sp. from the Japanese tree frog, Hyla japonica Günther, 1859, in Oita, Kyushu Island, Japan. Paracosmocercella resembles Cosmocercella and Cosmocercoides by having 2 rows of rosette papillae without plectanes ventrally in preanal region of male, but it is readily distinguished from Cosmocercella by lacking clear vesicle supporting rosette papillae and from Cosmocercoides by lacking rosette papillae in perianal region and having large-sized eggs, which hatch in uterus.

  19. Courtship in Frogs

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 12. Courtship in Frogs Role of Acoustic Communication in Amphibian Courtship Behaviour. Debjani Roy. General Article Volume 1 Issue 12 December 1996 pp 39-48 ...

  20. Prevalence of Batrachochytrium dendrobatidis in three species of wild frogs on Prince Edward Island, Canada.

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    Forzán, M J; Vanderstichel, R; Hogan, N S; Teather, K; Wood, J

    2010-09-02

    Chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), has resulted in the decline or extinction of approximately 200 frog species worldwide. It has been reported throughout much of North America, but its presence on Prince Edward Island (PEI), on the eastern coast of Canada, was unknown. To determine the presence and prevalence of Bd on PEI, skin swabs were collected from 115 frogs from 18 separate sites across the province during the summer of 2009. The swabs were tested through single round end-point PCR for the presence of Bd DNA. Thirty-one frogs were positive, including 25/93 (27%) green frogs Lithobates (Rana) clamitans, 5/20 (25%) northern leopard frogs L. (R.) pipiens, and 1/2 (50%) wood frogs L. sylvaticus (formerly R. sylvatica); 12 of the 18 (67%) sites had at least 1 positive frog. The overall prevalence of Bd infection was estimated at 26.9% (7.2-46.7%, 95% CI). Prevalence amongst green frogs and leopard frogs was similar, but green frogs had a stronger PCR signal when compared to leopard frogs, regardless of age (p < 0.001) and body length (p = 0.476). Amongst green frogs, juveniles were more frequently positive than adults (p = 0.001). Green frogs may be the most reliable species to sample when looking for Bd in eastern North America. The 1 wood frog positive for Bd was found dead from chytridiomycosis; none of the other frogs that were positive for Bd by PCR showed any obvious signs of illness. Further monitoring will be required to determine what effect Bd infection has on amphibian population health on PEI.

  1. Frogs and climate change in South Africa

    OpenAIRE

    Minter, Leslie Rory

    2011-01-01

    This article explores the relationship between frog declines and climate change, discusses the possible impact of climate change on the South African frog fauna, and highlights the necessity for increased research and monitoring of our frog populations.

  2. Frogs host faecal bacteria typically associated with humans.

    Science.gov (United States)

    Gibb, Karen; Schobben, Xavier; Christian, Keith

    2017-07-01

    Tree frogs commonly access drinking water tanks; this may have human health implications. Although amphibians might not be expected to host mammalian faecal indicator bacteria (FIB), it is possible that they may have human FIB on their skin after exposure to human waste. We collected faeces and skin wash from green tree frogs (Litoria caerulea) from a natural environment, a suburban site, and a suburban site near a creek occasionally contaminated with sewage effluent. We used molecular techniques to test for FIB that are routinely used to indicate human faecal contamination. Enterococci colonies were isolated from both faecal and skin wash samples, and specific markers (Enterococcus faecium and Bacteroides thetaiotaomicron) were found in frog faeces, demonstrating that these markers are not human- or mammalian-specific. Bacteroides thetaiotaomicron was detected in frogs from both natural and urban sites, but E. faecium was only associated with the sewage impacted site.

  3. Adaptive response in frogs chronically exposed to low doses of ionizing radiation in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Audette-Stuart, M., E-mail: stuartm@aecl.ca [Environmental Technologies Branch, Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ontario, K0J 1P0 (Canada); Kim, S.B.; McMullin, D.; Festarini, A.; Yankovich, T.L.; Carr, J.; Mulpuru, S. [Environmental Technologies Branch, Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ontario, K0J 1P0 (Canada)

    2011-06-15

    Using the micronucleus assay, decreased levels of DNA damage were found after high dose ionizing radiation exposure of liver cells taken from frogs inhabiting a natural environment with above-background levels of ionizing radiation, compared to cells taken from frogs inhabiting background areas. The data obtained from a small number of animals suggest that stress present in the above-background environment could induce an adaptive response to ionizing radiation. This study did not reveal harmful effects of exposure to low levels of radioactivity. On the contrary, stress present in the above-background area may serve to enhance cellular defense mechanisms. - Highlights: > Frogs were collected from background and higher tritium level habitats. > The micronucleus assay was conducted on liver cells obtained from the frogs. > No detrimental effects were noted in frogs exposed to elevated tritium. > Adaptive responses were observed in frogs exposed to elevated tritium.

  4. Abundance of Green Tree Frogs and Insects in Artificial Canopy Gaps in a Bottomland Hardwood Forest.

    Energy Technology Data Exchange (ETDEWEB)

    Horn, Scott; Hanula, James, L.; Ulyshen, Michael D.; Kilgo, John, C.

    2005-04-01

    ABSTRACT - We found more green tree frogs ( Hyla cinerea) n canopv gaps than in closed canopy forest. Of the 331 green tree frogs observed, 88% were in canopv gaps. Likewise, higher numbers and biomasses of insects were captured in the open gap habitat Flies were the most commonlv collected insect group accounting for 54% of the total capture. These data suggest that one reason green tree frogs were more abundant in canopy gaps was the increased availability of prey and that small canopy gaps provide early successional habitats that are beneficial to green tree frog populations.

  5. Abundance of green tree frogs and insects in artificial canopy gaps in a bottomland hardwood forest

    Science.gov (United States)

    Scott Horn; James L. Hanula; Michael D. Ulyshen; John C. Kilgo

    2005-01-01

    We found more green tree frogs (Hyla cinera) in canopy gaps than in closed canopy forest. Of the 331 gree ntree frogs observed, 88% were in canopy gaps. Likewise, higher numbers and biomasses of insects were captured in the open gap habitat. Flies were the most commonly collected insect group accounting for 54% of the total capture. These data...

  6. Lithobates sylvaticus (wood frog)

    Science.gov (United States)

    Fuller, Pam

    2016-01-01

    A single specimen found southwest of Hattiesburg in Timberton (31.270391oN, 89.327675oW; WGS 84). 23 July 2015. Gary, Kat, and Ron Lukens. Verifi ed by Kenneth Krysko, Florida Museum of Natural History (UF-Herpetology 176455). This species has never been recorded from the state of Mississippi before (Dodd 2013. Frogs of the United States and Canada – Volume 2. John Hopkins University Press, Baltimore, Maryland. 982 pp.). According to Dodd (2013), the closest population is located in east central Alabama, approximately 400 km to the northeast, as documented by Davis and Folkerts (1986. Brimleyana 12:29-50).

  7. Panamanian frog species host unique skin bacterial communities

    Directory of Open Access Journals (Sweden)

    Lisa K. Belden

    2015-10-01

    Full Text Available Vertebrates, including amphibians, host diverse symbiotic microbes that contribute to host disease resistance. Globally, and especially in montane tropical systems, many amphibian species are threatened by a chytrid fungus, Batrachochytrium dendrobatidis (Bd, that causes a lethal skin disease. Bd therefore may be a strong selective agent on the diversity and function of the microbial communities inhabiting amphibian skin. In Panamá, amphibian population declines and the spread of Bd have been tracked. In 2012, we completed a field survey in Panamá to examine frog skin microbiota in the context of Bd infection. We focused on three frog species and collected two skin swabs per frog from a total of 136 frogs across four sites that varied from west to east in the time since Bd arrival. One swab was used to assess bacterial community structure using 16S rRNA amplicon sequencing and to determine Bd infection status, and one was used to assess metabolite diversity, as the bacterial production of anti-fungal metabolites is an important disease resistance function. The skin microbiota of the three Panamanian frog species differed in OTU (operational taxonomic unit, ~bacterial species community composition and metabolite profiles, although the pattern was less strong for the metabolites. Comparisons between frog skin bacterial communities from Panamá and the US suggest broad similarities at the phylum level, but key differences at lower taxonomic levels. In our field survey in Panamá, across all four sites, only 35 individuals (~26% were Bd infected. There was no clustering of OTUs or metabolite profiles based on Bd infection status and no clear pattern of west-east changes in OTUs or metabolite profiles across the four sites. Overall, our field survey data suggest that different bacterial communities might be producing broadly similar sets of metabolites across frog hosts and sites. Community structure and function may not be as tightly coupled in

  8. Abundance of green tree frogs and insects in artificial canopy gaps in a bottomland hardwood forest.

    Energy Technology Data Exchange (ETDEWEB)

    Horn, Scott; Hanula, James L.; Ulyshen, Michael D.; Kilgo, John C.

    2005-01-01

    Horn, Scott, James L. Hanula, Michael D. Ulyshen, and John C. Kilgo. 2005. Abundance of green tree frogs and insects in artificial canopy gaps in a bottomland hardwood forest. Am. Midl. Nat. 153:321-326. Abstract: We found more green tree frogs (Hyla cinerea) in canopy gaps than in closed canopy forest. Of the 331 green tree frogs observed, 88% were in canopy gaps. Likewise, higher numbers and biomasses of insects were captured in the open gap habitat. Flies were the most commonly collected insect group accounting for 54% of the total capture. These data suggest that one reason green tree frogs were more abundant in canopy gaps was the increased availability of prey and that small canopy gaps provide early successional habitats that are beneficial to green tree frog populations.

  9. Antifungal activity of epithelial secretions from selected frog species ...

    African Journals Online (AJOL)

    This study aimed to investigate the antifungal activity of skin secretions from selected frogs (Amietia fuscigula, Strongylopus grayi and Xenopus laevis) and one toad (Amietophrynus pantherinus) of the south Western Cape Province of South Africa. Initially, different extraction techniques for the collection of skin secretions ...

  10. Life Histories of Frogs in the Namib Desert | Channing | African ...

    African Journals Online (AJOL)

    Large runoff surfaces collect the low rainfall (25 mm per year) in depressions in which the frogs breed. Phrynomerus is only active at night; males are aggressive towards one another; oviposition takes place in deep pools and development takes at least eight weeks. Bufo is active during the heat of the day; oviposition takes ...

  11. Ranavirus in wild edible frogs Pelophylax kl. esculentus in Denmark

    DEFF Research Database (Denmark)

    Ariel, Ellen; Kielgast, Jos; Svart, Hans Erik

    2009-01-01

    interviewed by phone and 10 cases were examined on suspicion of diseaseinduced mortality. All samples were negative for Bd. Ranavirus was isolated from 2 samples of recently dead frogs collected during a mass mortality event in an artificial pond near Slagelse, Denmark. The identity of the virus was confirmed...

  12. Wood frog adaptations to overwintering in Alaska: new limits to freezing tolerance.

    Science.gov (United States)

    Larson, Don J; Middle, Luke; Vu, Henry; Zhang, Wenhui; Serianni, Anthony S; Duman, John; Barnes, Brian M

    2014-06-15

    We investigated the ecological physiology and behavior of free-living wood frogs [Lithobates (Rana) sylvaticus] overwintering in Interior Alaska by tracking animals into natural hibernacula, recording microclimate, and determining frog survival in spring. We measured cryoprotectant (glucose) concentrations and identified the presence of antifreeze glycolipids in tissues from subsamples of naturally freezing frogs. We also recorded the behavior of wood frogs preparing to freeze in artificial hibernacula, and tissue glucose concentrations in captive wood frogs frozen in the laboratory to -2.5°C. Wood frogs in natural hibernacula remained frozen for 193 ± 11 consecutive days and experienced average (October-May) temperatures of -6.3°C and average minimum temperatures of -14.6 ± 2.8°C (range -8.9 to -18.1°C) with 100% survival (N=18). Mean glucose concentrations were 13-fold higher in muscle, 10-fold higher in heart and 3.3-fold higher in liver in naturally freezing compared with laboratory frozen frogs. Antifreeze glycolipid was present in extracts from muscle and internal organs, but not skin, of frozen frogs. Wood frogs in Interior Alaska survive freezing to extreme limits and durations compared with those described in animals collected in southern Canada or the Midwestern United States. We hypothesize that this enhancement of freeze tolerance in Alaskan wood frogs is due to higher cryoprotectant levels that are produced by repeated freezing and thawing cycles experienced under natural conditions during early autumn. © 2014. Published by The Company of Biologists Ltd.

  13. Distribution, structure and projections of the frog intracardiac neurons.

    Science.gov (United States)

    Batulevicius, Darius; Skripkiene, Gertruda; Batuleviciene, Vaida; Skripka, Valdas; Dabuzinskiene, Anita; Pauza, Dainius H

    2012-05-21

    Histochemistry for acetylcholinesterase was used to determine the distribution of intracardiac neurons in the frog Rana temporaria. Seventy-nine intracardiac neurons from 13 frogs were labelled iontophoretically by the intracellular markers Alexa Fluor 568 and Lucifer Yellow CH to determine their structure and projections. Total neuronal number per frog heart was (Mean ± SE) 1374 ± 56. Largest collections of neurons were found in the interatrial septum (46%), atrioventricular junction (25%) and venal sinus (12%). Among the intracellularly labelled neurons, we found the cells of unipolar (71%), multipolar (20%) and bipolar (9%) types. Multiple processes originated from the neuron soma, hillock and proximal axon. These processes projected onto adjacent neuron somata and cardiac muscle fibers within the interatrial septum. Average total length of the processes from proximal axon was 348 ± 50 μm. Average total length of processes from soma and hillock was less, 118 ± 27 μm and 109 ± 24 μm, respectively. The somata of 59% of neurons had bubble- or flake-shaped extensions. Most neurons from the major nerves in the interatrial septum sent their axons towards the ventricle. In contrast, most neurons from the ventral part of the interatrial septum sent their axons towards the atria. Our findings contradict to a view that the frog intracardiac ganglia contain only non-dendritic neurons of the unipolar type. We conclude that the frog intracardiac neurons are structurally complex and diverse. This diversity may account for the complicated integrative functions of the frog intrinsic cardiac ganglia. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Diseases of frogs and toads

    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

    This chapter presents information on infectious diseases of free-living frogs and toads that have completed metamorphosis. The diseases discussed in this chapter pertain principally to sub-adult and adult frogs and toads that are at least 60-90 days removed from completion of metamorphosis. The main emphasis of this chapter is the diseases found in amphibians of Canada and the United States. Diseases of recent metamorphs, larvae and amphibian eggs are presented in the chapters Diseases of Amphibian Eggs and Embryos and Diseases of Tadpoles. The smallest disease agents (viruses and bacteria) are presented first, followed by fungi, protozoa, helminths and ectoparasites. Diseases presented in this chapter are Ranaviral (iridovirus) infection Lucke frog herpesvirus (kidney cancer) Frog erythrocytic virus West Nile virus Red-leg disease (bacterial septicemia) Salmonellosis Chytrid fungal infection Basidiobolus fungi Dermosporidiosis Ichthyophoniasis Dermocystidium & Dermomycoides Myxozoa Ribeiroia flukes and Amphibian malformations Clinostomum metacercaria Aspects of each disease are presented to assist the biologist with recognition of diseases in the field. Hence, the major emphases for identification of diseases are the epizootiological aspects (host species, life stage, casualty numbers, etc) and gross findings ('lesions'). Descriptions of the microscopical, ultrastructural and cultural characteristics of each infectious agent were considered beyond the scope of this text. Detailed cultural and microscopical features of these disease agents are available in other reviews (Taylor et al., 2001; Green, 2001). Some diseases, while common in captive and zoo amphibians, are exceptionally rare in free-living frogs and toads, and therefore are omitted from this review. Among the diseases not presented are infections by chlamydia and mycobacteria, which occur principally in captive colonies of African clawed frogs (Xenopus, Hymenochirus, et al.) and northern leopard frogs

  15. Hind limb malformations in free-living northern leopard frogs (Rana pipiens) from Maine, Minnesota, and Vermont suggest multiple etiologies

    Science.gov (United States)

    Meteyer, C.U.; Loeffler, I.K.; Fallon, J.F.; Converse, K.A.; Green, E.; Helgen, J.C.; Kersten, S.; Levey, R.; Eaton-Poole, L.; Burkhart, J.G.

    2000-01-01

    Background Reports of malformed frogs have increased throughout the North American continent in recent years. Most of the observed malformations have involved the hind limbs. The goal of this study was to accurately characterize the hind limb malformations in wild frogs as an important step toward understanding the possible etiologies. Methods During 1997 and 1998, 182 recently metamorphosed northern leopard frogs (Rana pipiens) were collected from Minnesota, Vermont, and Maine. Malformed hind limbs were present in 157 (86%) of these frogs, which underwent necropsy and radiographic evaluation at the National Wildlife Health Center. These malformations are described in detail and classified into four major categories: (1) no limb (amelia); (2) multiple limbs or limb elements (polymelia, polydactyly, polyphalangy); (3) reduced limb segments or elements (phocomelia, ectromelia, ectrodactyly, and brachydactyly; and (4) distally complete but malformed limb (bone rotations, bridging, skin webbing, and micromelia). Results Amelia and reduced segments and/or elements were the most common finding. Frogs with bilateral hind limb malformations were not common, and in only eight of these 22 frogs were the malformations symmetrical. Malformations of a given type tended to occur in frogs collected from the same site, but the types of malformations varied widely among all three states, and between study sites within Minnesota. Conclusions Clustering of malformation type suggests that developmental events may produce a variety of phenotypes depending on the timing, sequence, and severity of the environmental insult. Hind limb malformations in free-living frogs transcend current mechanistic explanations of tetrapod limb development.

  16. Guinea Worm in a Frog

    Centers for Disease Control (CDC) Podcasts

    2017-03-09

    Dr. Mark Eberhard, a retired parasitologist and CDC guest researcher, discusses Guinea worm infection in a wild-caught frog.  Created: 3/9/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 3/9/2017.

  17. Salmonella Infection and Water Frogs

    Centers for Disease Control (CDC) Podcasts

    2010-01-12

    This podcast, featuring lead investigator Shauna Mettee, discusses the first known outbreak of Salmonella in people due to contact with water frogs.  Created: 1/12/2010 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 1/12/2010.

  18. Leap-Frogging Newton's Method

    Science.gov (United States)

    Kasturiarachi, A. Bathi

    2002-01-01

    Using Newton's method as an intermediate step, we introduce an iterative method that approximates numerically the solution of f(x) = 0. The method is essentially a leap-frog Newton's method. The order of convergence of the proposed method at a simple root is cubic and the computational efficiency in general is less, but close to that of Newton's…

  19. FROG - Fingerprinting Genomic Variation Ontology.

    Directory of Open Access Journals (Sweden)

    E Abinaya

    Full Text Available Genetic variations play a crucial role in differential phenotypic outcomes. Given the complexity in establishing this correlation and the enormous data available today, it is imperative to design machine-readable, efficient methods to store, label, search and analyze this data. A semantic approach, FROG: "FingeRprinting Ontology of Genomic variations" is implemented to label variation data, based on its location, function and interactions. FROG has six levels to describe the variation annotation, namely, chromosome, DNA, RNA, protein, variations and interactions. Each level is a conceptual aggregation of logically connected attributes each of which comprises of various properties for the variant. For example, in chromosome level, one of the attributes is location of variation and which has two properties, allosomes or autosomes. Another attribute is variation kind which has four properties, namely, indel, deletion, insertion, substitution. Likewise, there are 48 attributes and 278 properties to capture the variation annotation across six levels. Each property is then assigned a bit score which in turn leads to generation of a binary fingerprint based on the combination of these properties (mostly taken from existing variation ontologies. FROG is a novel and unique method designed for the purpose of labeling the entire variation data generated till date for efficient storage, search and analysis. A web-based platform is designed as a test case for users to navigate sample datasets and generate fingerprints. The platform is available at http://ab-openlab.csir.res.in/frog.

  20. CARE AND FEEDING OF FROGS

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Margaret; Chiang, Eugene, E-mail: mpan@astro.berkeley.edu [Department of Astronomy, University of California, Berkeley, CA 94720 (United States)

    2012-01-15

    'Propellers' are features in Saturn's A ring associated with moonlets that open partial gaps. They exhibit non-Keplerian motion (Tiscareno et al.); the longitude residuals of the best-observed propeller, 'Bleriot', appear consistent with a sinusoid of period {approx}4 years. Pan and Chiang proposed that propeller moonlets librate in 'frog resonances' with co-orbiting ring material. By analogy with the restricted three-body problem, they treated the co-orbital material as stationary in the rotating frame and neglected non-co-orbital material. Here we use simple numerical experiments to extend the frog model, including feedback due to the gap's motion, and drag associated with the Lindblad disk torques that cause Type I migration. Because the moonlet creates the gap, we expect the gap centroid to track the moonlet, but only after a time delay t{sub delay}, the time for a ring particle to travel from conjunction with the moonlet to the end of the gap. We find that frog librations can persist only if t{sub delay} exceeds the frog libration period P{sub lib}, and if damping from Lindblad torques balances driving from co-orbital torques. If t{sub delay} << Pl{sub ib}, then the libration amplitude damps to zero. In the case of Bleriot, the frog resonance model can reproduce the observed libration period P{sub lib} {approx_equal} 4 yr. However, our simple feedback prescription suggests that Bleriot's t{sub delay} {approx} 0.01P{sub lib}, which is inconsistent with the observed libration amplitude of 260 km. We urge more accurate treatments of feedback to test the assumptions of our toy models.

  1. Museum material reveals a frog parasite emergence after the invasion of the cane toad in Australia

    Directory of Open Access Journals (Sweden)

    Phalen David N

    2010-06-01

    Full Text Available Abstract Background A parasite morphologically indistinguishable from Myxidium immersum (Myxozoa: Myxosporea found in gallbladders of the invasive cane toad (Bufo marinus was identified in Australian frogs. Because no written record exists for such a parasite in Australian endemic frogs in 19th and early 20th century, it was assumed that the cane toad introduced this parasite. While we cannot go back in time ourselves, we investigated whether material at the museum of natural history could be used to retrieve parasites, and whether they were infected at the time of their collection (specifically prior to and after the cane toad translocation to Australia in 1935. Results Using the herpetological collection at the Australian Museum we showed that no myxospores were found in any animals (n = 115 prior to the cane toad invasion (1879-1935. The green and golden bell frog (Litoria aurea, the Peron's tree frog (Litoria peronii, the green tree frog (Litoria caerulea and the striped marsh frog (Limnodynastes peronii were all negative for the presence of the parasite using microscopy of the gallbladder content and its histology. These results were sufficient to conclude that the population was free from this disease (at the expected minimum prevalence of 5% at 99.7% confidence level using the 115 voucher specimens in the Australian Museum. Similarly, museum specimens (n = 29 of the green and golden bell frog from New Caledonia, where it was introduced in 19th century, did not show the presence of myxospores. The earliest specimen positive for myxospores in a gallbladder was a green tree frog from 1966. Myxospores were found in eight (7.1%, n = 112 frogs in the post cane toad introduction period. Conclusion Australian wildlife is increasingly under threat, and amphibian decline is one of the most dramatic examples. The museum material proved essential to directly support the evidence of parasite emergence in Australian native frogs. This parasite can be

  2. Museum material reveals a frog parasite emergence after the invasion of the cane toad in Australia.

    Science.gov (United States)

    Hartigan, Ashlie; Phalen, David N; Slapeta, Jan

    2010-06-10

    A parasite morphologically indistinguishable from Myxidium immersum (Myxozoa: Myxosporea) found in gallbladders of the invasive cane toad (Bufo marinus) was identified in Australian frogs. Because no written record exists for such a parasite in Australian endemic frogs in 19th and early 20th century, it was assumed that the cane toad introduced this parasite. While we cannot go back in time ourselves, we investigated whether material at the museum of natural history could be used to retrieve parasites, and whether they were infected at the time of their collection (specifically prior to and after the cane toad translocation to Australia in 1935). Using the herpetological collection at the Australian Museum we showed that no myxospores were found in any animals (n = 115) prior to the cane toad invasion (1879-1935). The green and golden bell frog (Litoria aurea), the Peron's tree frog (Litoria peronii), the green tree frog (Litoria caerulea) and the striped marsh frog (Limnodynastes peronii) were all negative for the presence of the parasite using microscopy of the gallbladder content and its histology. These results were sufficient to conclude that the population was free from this disease (at the expected minimum prevalence of 5%) at 99.7% confidence level using the 115 voucher specimens in the Australian Museum. Similarly, museum specimens (n = 29) of the green and golden bell frog from New Caledonia, where it was introduced in 19th century, did not show the presence of myxospores. The earliest specimen positive for myxospores in a gallbladder was a green tree frog from 1966. Myxospores were found in eight (7.1%, n = 112) frogs in the post cane toad introduction period. Australian wildlife is increasingly under threat, and amphibian decline is one of the most dramatic examples. The museum material proved essential to directly support the evidence of parasite emergence in Australian native frogs. This parasite can be considered one of the luckiest parasites

  3. Observation of Frog Species in State University of Malang as a Preliminary Effort on Frog Conservation

    OpenAIRE

    Wulandari, Dian Ratri; Habibi, Muhammad; Listyorini, Dwi

    2013-01-01

    Frog is an amphibian which widely distributed around the world. Indonesia houses 450 species which represent 11% of frog species in the world. In Java Island living 42 species of frogs and toads. Frogs can be used as an environment indicator due to the presence of frog in a particular place indicates that the place is stay natural and unpolluted. State University of Malang Campus #1 which is located in the heart of Malang District has been developing rapidly, currently. Thus, it requires for ...

  4. Dietary alkaloid sequestration in a poison frog: an experimental test of alkaloid uptake in Melanophryniscus stelzneri (Bufonidae).

    Science.gov (United States)

    Hantak, Maggie M; Grant, Taran; Reinsch, Sherri; McGinnity, Dale; Loring, Marjorie; Toyooka, Naoki; Saporito, Ralph A

    2013-12-01

    Several lineages of brightly colored anurans independently evolved the ability to secrete alkaloid-containing defensive chemicals from granular glands in the skin. These species, collectively referred to as 'poison frogs,' form a polyphyletic assemblage that includes some species of Dendrobatidae, Mantellidae, Myobatrachidae, Bufonidae, and Eleutherodactylidae. The ability to sequester alkaloids from dietary arthropods has been demonstrated experimentally in most poison frog lineages but not in bufonid or eleutherodactylid poison frogs. As with other poison frogs, species of the genus Melanophryniscus (Bufonidae) consume large numbers of mites and ants, suggesting they might also sequester defensive alkaloids from dietary sources. To test this hypothesis, fruit flies dusted with alkaloid/nutritional supplement powder were fed to individual Melanophryniscus stelzneri in two experiments. In the first experiment, the alkaloids 5,8-disubstituted indolizidine 235B' and decahydroquinoline were administered to three individuals for 104 days. In the second experiment, the alkaloids 3,5-disubstituted indolizidine 239Q and decahydroquinoline were given to three frogs for 153 days. Control frogs were fed fruit flies dusted only with nutritional supplement. Gas chromatography/mass spectrometry analyses revealed that skin secretions of all experimental frogs contained alkaloids, whereas those of all control frogs lacked alkaloids. Uptake of decahydroquinoline was greater than uptake of 5,8-disubstituted indolizidine, and uptake of 3,5-disubstituted indolizidine was greater than uptake of decahydroquinoline, suggesting greater uptake efficiency of certain alkaloids. Frogs in the second experiment accumulated a greater amount of alkaloid, which corresponds to the longer duration and greater number of alkaloid-dusted fruit flies that were consumed. These findings provide the first experimental evidence that bufonid poison frogs sequester alkaloid-based defenses from dietary

  5. Pharmacological Effects of Two Novel Bombesin-Like Peptides from the Skin Secretions of Chinese Piebald Odorous Frog (Odorrana schmackeri and European Edible Frog (Pelophylax kl. esculentus on Smooth Muscle

    Directory of Open Access Journals (Sweden)

    Xiaowei Zhou

    2017-10-01

    Full Text Available Bombesin-like peptides, which were identified from a diversity of amphibian skin secretions, have been demonstrated to possess several biological functions such as stimulation of smooth muscle contraction and regulation of food intake. Here, we report two novel bombesin-like peptides, bombesin-OS and bombesin-PE, which were isolated from Odorrana schmackeri and Pelophylax kl. esculentus, respectively. The mature peptides were identified and structurally confirmed by high performance Scliquid chromatography (HPLC and tandem mass spectrometry (MS/MS. Subsequently, the effects of these purified chemically-synthetic peptides on smooth muscle were determined in bladder, uterus, and ileum. The synthetic replications were revealed to have significant pharmacological effects on these tissues. The EC50 values of bombesin-OS for bladder, uterus and ileum, were 10.8 nM, 33.64 nM, and 12.29 nM, respectively. Furthermore, compared with bombesin-OS, bombesin-PE showed similar contractile activity on ileum smooth muscle and uterus smooth muscle, but had a higher potency on bladder smooth muscle. The EC50 value of bombesin-OS for bladder was around 1000-fold less than that of bombesin-PE. This suggests that bombesin-OS and bombesin-PE have unique binding properties to their receptors. The precursor of bombesin-OS was homologous with that of a bombesin-like peptide, odorranain-BLP-5, and bombesin-PE belongs to the ranatensin subfamily. We identified the structure of bombesin-OS and bombesin-PE, two homologues peptides whose actions may provide a further clue in the classification of ranid frogs, also in the provision of new drugs for human health.

  6. Pharmacological Effects of Two Novel Bombesin-Like Peptides from the Skin Secretions of Chinese Piebald Odorous Frog (Odorrana schmackeri) and European Edible Frog (Pelophylax kl. esculentus) on Smooth Muscle.

    Science.gov (United States)

    Zhou, Xiaowei; Ma, Chengbang; Zhou, Mei; Zhang, Yuning; Xi, Xinping; Zhong, Ruimin; Chen, Tianbao; Shaw, Chris; Wang, Lei

    2017-10-23

    Bombesin-like peptides, which were identified from a diversity of amphibian skin secretions, have been demonstrated to possess several biological functions such as stimulation of smooth muscle contraction and regulation of food intake. Here, we report two novel bombesin-like peptides, bombesin-OS and bombesin-PE, which were isolated from Odorrana schmackeri and Pelophylax kl. esculentus, respectively. The mature peptides were identified and structurally confirmed by high performance Scliquid chromatography (HPLC) and tandem mass spectrometry (MS/MS). Subsequently, the effects of these purified chemically-synthetic peptides on smooth muscle were determined in bladder, uterus, and ileum. The synthetic replications were revealed to have significant pharmacological effects on these tissues. The EC50 values of bombesin-OS for bladder, uterus and ileum, were 10.8 nM, 33.64 nM, and 12.29 nM, respectively. Furthermore, compared with bombesin-OS, bombesin-PE showed similar contractile activity on ileum smooth muscle and uterus smooth muscle, but had a higher potency on bladder smooth muscle. The EC50 value of bombesin-OS for bladder was around 1000-fold less than that of bombesin-PE. This suggests that bombesin-OS and bombesin-PE have unique binding properties to their receptors. The precursor of bombesin-OS was homologous with that of a bombesin-like peptide, odorranain-BLP-5, and bombesin-PE belongs to the ranatensin subfamily. We identified the structure of bombesin-OS and bombesin-PE, two homologues peptides whose actions may provide a further clue in the classification of ranid frogs, also in the provision of new drugs for human health.

  7. Is chytridiomycosis driving Darwin's frogs to extinction?

    Directory of Open Access Journals (Sweden)

    Claudio Soto-Azat

    Full Text Available Darwin's frogs (Rhinoderma darwinii and R. rufum are two species of mouth brooding frogs from Chile and Argentina that have experienced marked population declines. Rhinoderma rufum has not been found in the wild since 1980. We investigated historical and current evidence of Batrachochytrium dendrobatidis (Bd infection in Rhinoderma spp. to determine whether chytridiomycosis is implicated in the population declines of these species. Archived and live specimens of Rhinoderma spp., sympatric amphibians and amphibians at sites where Rhinoderma sp. had recently gone extinct were examined for Bd infection using quantitative real-time PCR. Six (0.9% of 662 archived anurans tested positive for Bd (4/289 R. darwinii; 1/266 R. rufum and 1/107 other anurans, all of which had been collected between 1970 and 1978. An overall Bd-infection prevalence of 12.5% was obtained from 797 swabs taken from 369 extant individuals of R. darwinii and 428 individuals representing 18 other species of anurans found at sites with current and recent presence of the two Rhinoderma species. In extant R. darwinii, Bd-infection prevalence (1.9% was significantly lower than that found in other anurans (7.3%. The prevalence of infection (30% in other amphibian species was significantly higher in sites where either Rhinoderma spp. had become extinct or was experiencing severe population declines than in sites where there had been no apparent decline (3.0%; x(2 = 106.407, P<0.001. This is the first report of widespread Bd presence in Chile and our results are consistent with Rhinoderma spp. declines being due to Bd infection, although additional field and laboratory investigations are required to investigate this further.

  8. Assessment of frog meat utilisation in Ibadan, Oyo state, Nigeria ...

    African Journals Online (AJOL)

    All the respondents (100%) buy the frogs utilised, have knowledge of the sellers and were unaware of frog farms in Nigeria. All the respondents (100%) considered frog meat desirable and preferred it when dried. Almost all the respondents (98.0%) have consumed frog meat more than 10 times. Majority of the respondents ...

  9. Severe sparganosis in Australian tree frogs.

    Science.gov (United States)

    Berger, Lee; Skerratt, Lee F; Zhu, Xing-Quan; Young, Sam; Speare, Rick

    2009-10-01

    Spargana of Spirometra erinacei infect many vertebrate species, but severe disease from sparganosis has been reported from few host species. Information on the effects of this common, introduced tapeworm of cats on Australian frogs is lacking. Our survey to detect significant diseases in free-ranging amphibians in eastern Australia between 1993 and 2000 revealed that infection with spargana (plerocercoids) of S. erinacei occurred in 12/243 (4.9%) sick frogs. Infections occurred in skeletal muscle and subcutis, especially the thighs, of large adults of Litoria caerulea, Litoria aurea, Litoria gracilenta, and Litoria peronii. Three frogs were also infected in the coelomic cavity. Heavy burdens in seven frogs were associated with poor body condition and debilitating lesions, whereas lighter infections in five sick frogs were considered likely to be incidental to other diseases. In severe infections, a large proportion of thigh muscle was replaced with spargana and various amounts of fibrosis, and some frogs also had myonecrosis, granulomatous inflammation, hemorrhage, and skin ulceration. Concurrent infections were common. Our findings suggest sparganosis is one of a few currently recognized serious diseases affecting free-ranging frogs in Australia.

  10. Convergent evolution of chemical defense in poison frogs and arthropod prey between Madagascar and the Neotropics.

    Science.gov (United States)

    Clark, Valerie C; Raxworthy, Christopher J; Rakotomalala, Valérie; Sierwald, Petra; Fisher, Brian L

    2005-08-16

    With few exceptions, aposematically colored poison frogs sequester defensive alkaloids, unchanged, from dietary arthropods. In the Neotropics, myrmicine and formicine ants and the siphonotid millipede Rhinotus purpureus are dietary sources for alkaloids in dendrobatid poison frogs, yet the arthropod sources for Mantella poison frogs in Madagascar remained unknown. We report GC-MS analyses of extracts of arthropods and microsympatric Malagasy poison frogs (Mantella) collected from Ranomafana, Madagascar. Arthropod sources for 11 "poison frog" alkaloids were discovered, 7 of which were also detected in microsympatric Mantella. These arthropod sources include three endemic Malagasy ants, Tetramorium electrum, Anochetus grandidieri, and Paratrechina amblyops (subfamilies Myrmicinae, Ponerinae, and Formicinae, respectively), and the pantropical tramp millipede R. purpureus. Two of these ant species, A. grandidieri and T. electrum, were also found in Mantella stomachs, and ants represented the dominant prey type (67.3% of 609 identified stomach arthropods). To our knowledge, detection of 5,8-disubstituted (ds) indolizidine iso-217B in T. electrum represents the first izidine having a branch point in its carbon skeleton to be identified from ants, and detection of 3,5-ds pyrrolizidine 251O in A. grandidieri represents the first ponerine ant proposed as a dietary source of poison frog alkaloids. Endemic Malagasy ants with defensive alkaloids (with the exception of Paratrechina) are not closely related to any Neotropical species sharing similar chemical defenses. Our results suggest convergent evolution for the acquisition of defensive alkaloids in these dietary ants, which may have been the critical prerequisite for subsequent convergence in poison frogs between Madagascar and the Neotropics.

  11. Hematologic and plasma biochemical reference intervals for health monitoring of wild Australian tree frogs.

    Science.gov (United States)

    Young, Sam; Warner, Jeff; Speare, Rick; Berger, Lee; Skerratt, Lee F; Muller, Reinhold

    2012-12-01

    Few hematologic and biochemical reference intervals for wild amphibians have been established. Reference values would aid in early detection of emerging infectious diseases, which are a significant problem for amphibian conservation efforts. We aimed to establish reference intervals for a wide range of hematologic and plasma biochemistry variables for 2 species of Australian tree frogs, describe morphologic features of leukocytes, and analyze the effects of season, year, and parasite status on blood values. Blood specimens were collected from reference populations of wild adult Australian tree frogs, Litoria caerulea and L infrafrenata, for analysis of hematologic (manual) variables, plasma biochemical (automated) analytes, and plasma and serum proteins using automated methods, refractometry, and electrophoresis. Inter- and intraspecies differences were found in L caerulea (n = 80) and L infrafrenata (n = 66) frogs for hematologic and biochemical variables. Intraspecies differences were largely associated with seasonal variations. In the dry season, both species had higher WBC counts, with higher lymphocyte counts in L caerulea and higher neutrophil counts in L infrafrenata, and uric acid concentrations. In the wet season, both species had higher glucose and potassium concentrations, L caerulea frogs had higher neutrophil counts, and L infrafrenata frogs had higher total protein, phosphorus, and sodium concentrations, AST activity, PCV, hemoglobin concentration, and RBC, thrombocyte, and basophil counts. Hemogregarines were identified in 19% of blood samples from L infrafrenata frogs; multiple hematologic and biochemical variables were altered in infected frogs. Wide interspecies and seasonal variations highlight the need to establish species- and season-specific reference intervals for amphibians. Hematologic and plasma biochemical reference values should be useful in assessing the health status and in detecting emerging diseases in wild amphibians. © 2012

  12. Cryoprotectants and extreme freeze tolerance in a subarctic population of the wood frog.

    Directory of Open Access Journals (Sweden)

    Jon P Costanzo

    Full Text Available Wood frogs (Rana sylvatica exhibit marked geographic variation in freeze tolerance, with subarctic populations tolerating experimental freezing to temperatures at least 10-13 degrees Celsius below the lethal limits for conspecifics from more temperate locales. We determined how seasonal responses enhance the cryoprotectant system in these northern frogs, and also investigated their physiological responses to somatic freezing at extreme temperatures. Alaskan frogs collected in late summer had plasma urea levels near 10 μmol ml-1, but this level rose during preparation for winter to 85.5 ± 2.9 μmol ml-1 (mean ± SEM in frogs that remained fully hydrated, and to 186.9 ± 12.4 μmol ml-1 in frogs held under a restricted moisture regime. An osmolality gap indicated that the plasma of winter-conditioned frogs contained an as yet unidentified osmolyte(s that contributed about 75 mOsmol kg-1 to total osmotic pressure. Experimental freezing to -8°C, either directly or following three cycles of freezing/thawing between -4 and 0°C, or -16°C increased the liver's synthesis of glucose and, to a lesser extent, urea. Concomitantly, organs shed up to one-half (skeletal muscle or two-thirds (liver of their water, with cryoprotectant in the remaining fluid reaching concentrations as high as 0.2 and 2.1 M, respectively. Freeze/thaw cycling, which was readily survived by winter-conditioned frogs, greatly increased hepatic glycogenolysis and delivery of glucose (but not urea to skeletal muscle. We conclude that cryoprotectant accrual in anticipation of and in response to freezing have been greatly enhanced and contribute to extreme freeze tolerance in northern R. sylvatica.

  13. Cryoprotectants and extreme freeze tolerance in a subarctic population of the wood frog.

    Science.gov (United States)

    Costanzo, Jon P; Reynolds, Alice M; do Amaral, M Clara F; Rosendale, Andrew J; Lee, Richard E

    2015-01-01

    Wood frogs (Rana sylvatica) exhibit marked geographic variation in freeze tolerance, with subarctic populations tolerating experimental freezing to temperatures at least 10-13 degrees Celsius below the lethal limits for conspecifics from more temperate locales. We determined how seasonal responses enhance the cryoprotectant system in these northern frogs, and also investigated their physiological responses to somatic freezing at extreme temperatures. Alaskan frogs collected in late summer had plasma urea levels near 10 μmol ml-1, but this level rose during preparation for winter to 85.5 ± 2.9 μmol ml-1 (mean ± SEM) in frogs that remained fully hydrated, and to 186.9 ± 12.4 μmol ml-1 in frogs held under a restricted moisture regime. An osmolality gap indicated that the plasma of winter-conditioned frogs contained an as yet unidentified osmolyte(s) that contributed about 75 mOsmol kg-1 to total osmotic pressure. Experimental freezing to -8°C, either directly or following three cycles of freezing/thawing between -4 and 0°C, or -16°C increased the liver's synthesis of glucose and, to a lesser extent, urea. Concomitantly, organs shed up to one-half (skeletal muscle) or two-thirds (liver) of their water, with cryoprotectant in the remaining fluid reaching concentrations as high as 0.2 and 2.1 M, respectively. Freeze/thaw cycling, which was readily survived by winter-conditioned frogs, greatly increased hepatic glycogenolysis and delivery of glucose (but not urea) to skeletal muscle. We conclude that cryoprotectant accrual in anticipation of and in response to freezing have been greatly enhanced and contribute to extreme freeze tolerance in northern R. sylvatica.

  14. Expression analysis and identification of antimicrobial peptide transcripts from six North American frog species

    Science.gov (United States)

    Robertson, Laura S.; Fellers, Gary M.; Marranca, Jamie Marie; Kleeman, Patrick M.

    2013-01-01

    Frogs secrete antimicrobial peptides onto their skin. We describe an assay to preserve and analyze antimicrobial peptide transcripts from field-collected skin secretions that will complement existing methods for peptide analysis. We collected skin secretions from 4 North American species in the field in California and 2 species in the laboratory. Most frogs appeared healthy after release; however, Rana boylii in the Sierra Nevada foothills, but not the Coast Range, showed signs of morbidity and 2 died after handling. The amount of total RNA extracted from skin secretions was higher in R. boylii and R. sierrae compared to R. draytonii, and much higher compared to Pseudacris regilla. Interspecies variation in amount of RNA extracted was not explained by size, but for P. regilla it depended upon collection site and date. RNA extracted from skin secretions from frogs handled with bare hands had poor quality compared to frogs handled with gloves or plastic bags. Thirty-four putative antimicrobial peptide precursor transcripts were identified. This study demonstrates that RNA extracted from skin secretions collected in the field is of high quality suitable for use in sequencing or quantitative PCR (qPCR). However, some species do not secrete profusely, resulting in very little extracted RNA. The ability to measure transcript abundance of antimicrobial peptides in field-collected skin secretions complements proteomic analyses and may provide insight into transcriptional mechanisms that could affect peptide abundance.

  15. Frog Call Survey Summary 2002-2006

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Since 2002, Patuxent Research Refuge has conducted frog surveys on South Tract, Central Tract, and North Tract locations. These surveys are conducted by Patuxent...

  16. Papuan Hylid Frogs of the Genus Hyla

    NARCIS (Netherlands)

    Tyler, M.J.

    1968-01-01

    CONTENTS Introduction............... 3 History of the study of Papuan Hyla......... 4 The Papuan frog fauna............ 6 Materials, methods and terminology.......... 8 Geographical nomenclature............ 11 Locality names.............. 14 The genus Hyla Laurenti............ 16 Checklist of Papuan

  17. Food Habits of the Endemic Long Legged Wood Frog, Rana Pseudodalmatina (Amphibia, Ranidae, in Northern Iran

    Directory of Open Access Journals (Sweden)

    Najibzadeh M.

    2016-08-01

    Full Text Available Iranian long legged wood frog, Rana pseudodalmatina Eiselt & Schmidtler, 1971 is a brown frog species endemic to the Hyrcanian forest. The objective of the present study is to collect detailed information on the feeding habits of 44 specimens of this species (24 ♂, 20 ♀ by analyzing the stomach contents of individuals from 10 populations inhabiting range. The food habit of R. pseudodalmatina generally varies by the availability of surrounding prey items, and it is a foraging predator, the food of which consists largely of Coleoptera (mainly Carabidae, Dytiscidae and Haliplidae, Diptera (Muscidae and Hymenoptera (Formicidae, and no difference was found between females and males in the stomach content.

  18. On new and little-known Frogs from the Malayan Archipelago

    NARCIS (Netherlands)

    Horst, R.

    1883-01-01

    Being occupied with an examination of the frogs from the Malayan Archipelago in our Collections, the type-specimens of Bufo cruentatus (Schleg.) Tschudi and Hylaplesia borbonica Kuhl & v. Hass. came under my hand, and I was not a little surprised to see that the later authors believe those two

  19. Itraconazole treatment reduces Batrachochytrium dendrobatidis prevalence and increases overwinter field survival in juvenile Cascades frogs

    Science.gov (United States)

    B.M. Hardy; K.L. Pope; J. Piovia-Scott; R.N. Brown; J.E. Foley

    2015-01-01

    The global spread of the fungal pathogen Batrachochytrium dendrobatidis (Bd) has led to widespread extirpation of amphibian populations. During an intervention aimed at stabilizing at-risk populations, we treated wild-caught Cascades frogs Rana cascadae with the antifungal drug itraconazole. In fall 2012, we collected 60 recently...

  20. Functional analysis for gut microbes of the brown tree frog

    National Research Council Canada - National Science Library

    Weng, Francis Cheng-Hsuan; Yang, Yi-Ju; Wang, Daryi

    2016-01-01

    .... In amphibians, the bacteria in the intestinal tract show a drop in bacterial counts. The proportion of pathogenic bacteria is greater in hibernating frogs than that found in nonhibernating frogs...

  1. Exposure of northern leopard frogs in the Green Bay ecosystem to polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans is measured by direct chemistry but not hepatic ethoxyresorufin-O-deethylase activity

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Y.W.; Karasov, W.H.; Patnode, K.A.; Jefcoate, C.R.

    1999-10-01

    The authors measured concentrations of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) in northern leopard frogs collected from the Green Bay ecosystem and explored the catalytic activity of hepatic cytochrome P450-associated monooxygenase (P450 enzyme) as a biomarker for exposure to aryl hydrocarbon receptor (AhR) agonists. The two hypotheses tested were PCH concentrations in northern leopard frogs would be positively correlated with sediment polychlorinated hydrocarbon (PCH) levels in wetland habitats along a contamination gradient and hepatic ethoxyresorufin-O-deethylase (EROD) activity of northern leopard frogs, which is presumably mediated by aryl hydrocarbon receptor (AhR), would be positively correlated with PCH concentrations in frog carcasses from different collection sites. In 1994 and 1995, frogs from seven sites along the lower Fox River and Green Bay, USA, were assayed for hepatic EROD activities and whole carcass concentrations of PCBs, PCDDs, and PCDFs. Tissue total PCB concentrations ranging from 3 to 154 ng/g were significantly correlated with sediment PCB levels. Only one PCDD and two PCDFs at concentrations of 6 to 8 pg/g were found in the frogs collected with frog body weight and was similar among sites except for Peter's Marsh. No significant correlation was found between EROD activity and carcass PCB concentration. This result was consistent with the fact that the frogs collected from the Green Bay ecosystem had relatively low PCB concentrations compared with what was required for induction in the laboratory.

  2. FROG: The Fast & Realistic OPENGL Displayer

    CERN Document Server

    Quertenmont, Loic

    2009-01-01

    FROG is a generic framework dedicated to visualisation of events in high energy experiment. It is suitable to any particular physics experiment or detector design. The code is light (<3 MB) and fast (browsing time ~20 events per second for a large High Energy Physics experiment) and can run on various operating systems, as its object-oriented structure (C++) relies on the cross-platform OPENGL and GLUT libraries. Moreover, FROG does not require installation of third party libraries for the visualisation. This document describes the features and principles of FROG version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisations, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally, several examples of its current applications are presented for illustration.

  3. Muscles of the pes of hylid frogs.

    Science.gov (United States)

    Burton, Thomas C

    2004-05-01

    Complete or partial dissection of the foot musculature of 404 hylid frogs representing 247 species and 33 genera, along with representatives of eight other families, revealed a number of apomorphic characters that distinguish the hyloid frogs (Hylidae plus Allophryne and Centrolenidae) from other bufonoid frogs. Additional characters were found to define some of the hylid subfamilies. Addition of characters from the foot musculature to Duellman's phylogenetic tree of the hyloids produced a tree in which Allophryne and Centrolenidae are nested within Hylidae. Support was found for the monophyly of the 30-chromosome group within Hyla, and for a large number of the groups that comprise "Boana," viz., the Hyla albomarginata, H. albopunctata, H. boans (except H. vasta), H. geographica, and H. pulchella groups, but foot muscle characters provide no information relating to relationships of the West Indies hylines. Copyright 2004 Wiley-Liss, Inc.

  4. FROG The Fast and Realistic OPENGL Displayer

    CERN Document Server

    Quertenmont, Loic

    2009-01-01

    FROG is a generic framework dedicated to visualisation of events in high energy experiment. It is suitable to any particular physics experiment or detector design. The code is light ($<3\\textrm{MB}$) and fast (browsing time ~20 events per second for a large High Energy Physics experiment) and can run on various operating systems, as its object-oriented structure (C++) relies on the cross-platform OPENGL and GLUT libraries. Moreover, FROG does not require installation of third party libraries for the visualisation. This document describes the features and principles of FROG version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisations, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally, several examples of its current applications are presented for illustration.

  5. The Observation of Frog Species at State University of Malang as a Preliminary Effort on Frog Conservation

    OpenAIRE

    Dian Ratri Wulandari; Muhammad Habibi; Dwi Listyorini

    2013-01-01

    Frog is an amphibian which is widely spread around the world. Indonesia houses 450 species which represent 11% of frog species in the world. In Java Island alone, there live 42 species of frogs and toads. Frogs can be used as an environment indicator in that the presence of frog in a particular place indicates that the place stays natural and unpolluted. The 1st Campus of State University of Malang, which is located in the heart of Malang District, has been developing rapidly currently. Thus,...

  6. [Meiotic chromosomes of the tree frog Smilisca baudinii (Anura: Hylidae)].

    Science.gov (United States)

    Hernández-Guzmán, Javier; Arias-Rodriguez, Lenin; Indy, Jeane Rimber

    2011-03-01

    The Mexican tree frog Smilisca baudinii, is a very common frog in Central America. In spite their importance to keep the ecological equilibrium of the rainforest, its biology and genetics are poorly known. In order to contribute with its biological knowledge, we described the typical meiotic karyotype based in standard cytogenetic protocols to specimens collected in Tabasco, Mexico. The study was centered in the analysis of 131 chromosome spreads at meiotic stage from two adults of the species (one female and one male). The metaphase analysis allowed the establishment of the modal haploid number of 1n = 12 bivalent chromosomes. The chromosomic formulae from the haploid bivalent karyotype was integrated by 12 biarmed chromosomes characterized by twelve pairs of metacentric-submetacentric (msm) chromosomes. The meiotic counting gives the idea that diploid chromosome number is integrated by a complement of 2n = 24 biarmed chromosomes. The presence of sex chromosomes from female and male meiotic spreads was not observed. Current results suggest that S. baudinii chromosome structure is well shared among Hylidae family and "B" chromosomes are particular structures that have very important evolutionary consequences in species diversification.

  7. Treatment of Argulus sp. infestation of river frogs.

    Science.gov (United States)

    Wolfe, B A; Harms, C A; Groves, J D; Loomis, M R

    2001-11-01

    Ten river frog tadpoles (Rana hecksheri) were collected from Pointsett State Park in South Carolina in April 1995. They were housed together in a tank at the North Carolina Zoological Park. Although no skin lesions were evident at collection, skin scrapings performed 4 weeks later revealed numerous immature and adult Argulus sp. on the tails and dorsal trunks of many of the tadpoles. The adult parasites were removed manually, and the tadpoles were treated with lufenuron (15 mg/l; Program, Novartis Animal Health, Greensboro, N.C.) and sodium chloride (3 g/l) in the tank water for 3 weeks. A single immature Argulus was found on a skin scraping on day 2 of treatment, and no parasites were seen thereafter on skin scrapings obtained through day 28 after the initiation of treatment. Metamorphosis occurred in all tadpoles within 4 weeks of initiating treatment. No deleterious effects of the treatment were noted.

  8. Endemic infection of the amphibian chytrid fungus in a frog community post-decline.

    Directory of Open Access Journals (Sweden)

    Richard W R Retallick

    2004-11-01

    Full Text Available The chytrid fungus Batrachochytrium dendrobatidis has been implicated in the decline and extinction of numerous frog species worldwide. In Queensland, Australia, it has been proposed as the cause of the decline or apparent extinction of at least 14 high-elevation rainforest frog species. One of these, Taudactylus eungellensis, disappeared from rainforest streams in Eungella National Park in 1985-1986, but a few remnant populations were subsequently discovered. Here, we report the analysis of B. dendrobatidis infections in toe tips of T. eungellensis and sympatric species collected in a mark-recapture study between 1994 and 1998. This longitudinal study of the fungus in individually marked frogs sheds new light on the effect of this threatening infectious process in field, as distinct from laboratory, conditions. We found a seasonal peak of infection in the cooler months, with no evidence of interannual variation. The overall prevalence of infection was 18% in T. eungellensis and 28% in Litoria wilcoxii/jungguy, a sympatric frog that appeared not to decline in 1985-1986. No infection was found in any of the other sympatric species. Most importantly, we found no consistent evidence of lower survival in T. eungellensis that were infected at the time of first capture, compared with uninfected individuals. These results refute the hypothesis that remnant populations of T. eungellensis recovered after a B. dendrobatidis epidemic because the pathogen had disappeared. They show that populations of T. eungellensis now persist with stable, endemic infections of B. dendrobatidis.

  9. Accumulation of pesticides in pacific chorus frogs (Pseudacris regilla) from California's Sierra Nevada Mountains, USA

    Science.gov (United States)

    Smalling, Kelly L.; Fellers, Gary M.; Kleeman, Patrick M.; Kuivila, Kathryn

    2013-01-01

    Pesticides are receiving increasing attention as potential causes of amphibian declines, acting singly or in combination with other stressors, but limited information is available on the accumulation of current-use pesticides in tissue. The authors examined potential exposure and accumulation of currently used pesticides in pond-breeding frogs (Pseudacris regilla) collected from 7 high elevations sites in northern California. All sites sampled are located downwind of California's highly agricultural Central Valley and receive inputs of pesticides through precipitation and/or dry deposition. Whole frog tissue, water, and sediment were analyzed for more than 90 current-use pesticides and pesticide degradates using gas chromatography–mass spectrometry. Two fungicides, pyraclostrobin and tebuconazole, and one herbicide, simazine, were the most frequently detected pesticides in tissue samples. Median pesticide concentration ranged from 13 µg/kg to 235 µg/kg wet weight. Tebuconazole and pyraclostrobin were the only 2 compounds observed frequently in frog tissue and sediment. Significant spatial differences in tissue concentration were observed, which corresponded to pesticide use in the upwind counties. Data generated indicated that amphibians residing in remote locations are exposed to and capable of accumulating current-use pesticides. A comparison of P. regilla tissue concentrations with water and sediment data indicated that the frogs are accumulating pesticides and are potentially a more reliable indicator of exposure to this group of pesticides than either water or sediment.

  10. Effect of magnetic fields on green color formation in frog skin

    Science.gov (United States)

    Kashiwagi, H.; Kashiwagi, A.; Iwasaka, M.

    2017-05-01

    The present work is focused on a dynamic and efficient optical control system that is made possible by investigation of the body surfaces of various animals. Specifically, we expect Japanese tree frog (Hyla japonica) skin to provide a model for a flexible display device actuator mechanism. Tree frogs change body color from their original green to other colors in response to background colors. The color formation is controlled not only by chromatophores, but also by guanine microcrystals in iridophores. We collected sample microcrystals from the frog's dorsal skin and made a model display sheet using the green skin layers. The transparent chamber that contained the crystal suspension was layered to enhance light reflection. Sheet color was observed while the angle of light incidence was varied, with and without magnetic field exposure at 0.3 T. A slight increase in red and green intensity was detected. Additionally, reflected intensity increased with increasing angle of incidence. These results indicate that the guanine crystal platelets in frog skin can efficiently switch the reflected light direction under application of a magnetic field. This in turn suggests that a several-micron-sized microcrystal of this type is a candidate material for development of flexible optical chips for ambient light control.

  11. Molecular Confirmation of Frogs (Anura) as Hosts of Corethrellidae (Diptera) in the Southeastern United States.

    Science.gov (United States)

    Camp, Jeremy V; Irby, William S

    2017-09-01

    Flies in the family Corethrellidae Edwards 1932 (Diptera) are known to be attracted to the mating calls of male frogs. For the first time, the hosts of corethrellids were identified to species by analyzing bloodmeals taken from resting female flies. A portion of the cytochrome b gene was amplified and sequenced from blood-engorged flies using vertebrate-specific primers. The flies were collected over 6 yr at two locations in the southeastern United States from resting boxes and natural resting sites (rodent burrows). Potential host abundance focused on frog surveillance, and estimation relied on visual encounters, passive trapping (artificial refugia), and call surveys. This study confirms that corethrellids take blood from tree frogs (Hylidae); however, it was found that true frogs (Lithobates Fitzinger 1843 (Ranidae: Anura) sp.) were the principal host selected by Corethrella brakeleyi (Coquillett 1902) (~73% of identified bloodmeals). These preliminary data suggest that host selection of Corethrella Freeman 1962 sp. is not necessarily correlated with host calling abundance. © The Author 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  12. Accumulation of pesticides in Pacific chorus frogs (Pseudacris regilla) from California's Sierra Nevada Mountains, USA.

    Science.gov (United States)

    Smalling, Kelly L; Fellers, Gary M; Kleeman, Patrick M; Kuivila, Kathryn M

    2013-09-01

    Pesticides are receiving increasing attention as potential causes of amphibian declines, acting singly or in combination with other stressors, but limited information is available on the accumulation of current-use pesticides in tissue. The authors examined potential exposure and accumulation of currently used pesticides in pond-breeding frogs (Pseudacris regilla) collected from 7 high elevations sites in northern California. All sites sampled are located downwind of California's highly agricultural Central Valley and receive inputs of pesticides through precipitation and/or dry deposition. Whole frog tissue, water, and sediment were analyzed for more than 90 current-use pesticides and pesticide degradates using gas chromatography-mass spectrometry. Two fungicides, pyraclostrobin and tebuconazole, and one herbicide, simazine, were the most frequently detected pesticides in tissue samples. Median pesticide concentration ranged from 13 µg/kg to 235 µg/kg wet weight. Tebuconazole and pyraclostrobin were the only 2 compounds observed frequently in frog tissue and sediment. Significant spatial differences in tissue concentration were observed, which corresponded to pesticide use in the upwind counties. Data generated indicated that amphibians residing in remote locations are exposed to and capable of accumulating current-use pesticides. A comparison of P. regilla tissue concentrations with water and sediment data indicated that the frogs are accumulating pesticides and are potentially a more reliable indicator of exposure to this group of pesticides than either water or sediment. Copyright © 2013 SETAC.

  13. Effects on seventh-grade students' achievement and science anxiety of alternatives to conventional frog dissection

    Science.gov (United States)

    Marszalek, Christine Susan

    1998-12-01

    The purpose of this study in a suburban school district was to investigate and compare the level of learning and long-term retention of frog internal anatomy between seventh-grade students using an interactive CD tutorial, a desktop microworld, and conventional frog dissection. Students' anxiety toward science was also compared across the three treatment groups and between genders. Additional data on the students' preferred learning style were used to explore possible interaction effects with their respective instructional activity. Subjects participating in the study were all seventh-grade students in one junior-high school, numbering 280 in total. Classes were randomly assigned to the three modes of instruction for the dissection of a frog: a CD-tutorial dissection, a desktop microworld dissection, and a conventional dissection. The Conventional treatment was the traditional physical dissection using a preserved frog specimen and lab dissection tools. The CD-Tutorial treatment was the interactive tutorial Digital Frog from Digital Frog International. The Microworld treatment was a desktop microworld environment composed of Operation Frog on CD supplemented with other programs to provide additional avenues for learning. Data collection and testing occurred prior to treatment, one day after treatment, and three months after treatment. Data collected showed mixed results for all measures taken. The differences in achievement gained favoring the conventional treatment from pretest to both posttests appear to have leveled out somewhat over time. Although anxiety levels declined for both genders after treatment, females continued to report significantly higher science anxiety than males. There appears to be a relationship between treatment and gender in terms of effect on science anxiety. For all three measures taken--pretest, immediate posttest and delayed posttest--no significant difference in achievement by learning style was observed. Learning style alone does not

  14. Of volcanoes, saints, trash, and frogs

    DEFF Research Database (Denmark)

    Andersen, Astrid Oberborbeck

    , at the same time as political elections and economic hardship. During one year of ethnographic fieldwork volcanoes, saints, trash and frogs were among the nonhuman entities referred to in conversations and engaged with when responding to the changes that trouble the world and everyday life of Arequipans...

  15. Return of the Tarahumara frog to Arizona

    Science.gov (United States)

    James C. Rorabaugh; Stephen F. Hale; Michael J. Sredl; Craig Ivanyi

    2005-01-01

    The last wild Tarahumara frog (Rana tarahumarae) in Arizona was found dead in Big Casa Blanca Canyon, Santa Rita Mountains, in May 1983. However, the species is still well represented in the majority of its range in the northern Sierra Madre Occidental and adjacent Sky Islands of Sonora and Chihuahua. Plans to re-establish R. tarahumarae...

  16. Water Frogs, Aquariums, and Salmonella -- Oh My!

    Centers for Disease Control (CDC) Podcasts

    2009-12-09

    This CDC Kidtastics podcast discusses how people can get Salmonella from water frogs and aquariums.  Created: 12/9/2009 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 12/9/2009.

  17. Frog Swarms: Earthquake Precursors or False Alarms?

    Directory of Open Access Journals (Sweden)

    Rachel A. Grant

    2013-10-01

    Full Text Available In short-term earthquake risk forecasting, the avoidance of false alarms is of utmost importance to preclude the possibility of unnecessary panic among populations in seismic hazard areas. Unusual animal behaviour prior to earthquakes has been reported for millennia but has rarely been scientifically documented. Recently large migrations or unusual behaviour of amphibians have been linked to large earthquakes, and media reports of large frog and toad migrations in areas of high seismic risk such as Greece and China have led to fears of a subsequent large earthquake. However, at certain times of year large migrations are part of the normal behavioural repertoire of amphibians. News reports of “frog swarms” from 1850 to the present day were examined for evidence that this behaviour is a precursor to large earthquakes. It was found that only two of 28 reported frog swarms preceded large earthquakes (Sichuan province, China in 2008 and 2010. All of the reported mass migrations of amphibians occurred in late spring, summer and autumn and appeared to relate to small juvenile anurans (frogs and toads. It was concluded that most reported “frog swarms” are actually normal behaviour, probably caused by juvenile animals migrating away from their breeding pond, after a fruitful reproductive season. As amphibian populations undergo large fluctuations in numbers from year to year, this phenomenon will not occur on a yearly basis but will depend on successful reproduction, which is related to numerous climatic and geophysical factors. Hence, most large swarms of amphibians, particularly those involving very small frogs and occurring in late spring or summer, are not unusual and should not be considered earthquake precursors. In addition, it is likely that reports of several mass migration of small toads prior to the Great Sichuan Earthquake in 2008 were not linked to the subsequent M = 7.9 event (some occurred at a great distance from the epicentre

  18. Evidence of maternal provisioning of alkaloid-based chemical defenses in the strawberry poison frog Oophaga pumilio.

    Science.gov (United States)

    Stynoski, Jennifer L; Torres-Mendoza, Yaritbel; Sasa-Marin, Mahmood; Saporito, Ralph A

    2014-03-01

    Many organisms use chemical defenses to reduce predation risk. Aposematic dendrobatid frogs sequester alkaloid-based chemical defenses from a diet of arthropods, but research on these defenses has been limited to adults. Herein, we investigate chemical defense across development in a dendrobatid frog, Oophaga pumilio. This species displays complex parental care: at hatching, mothers transport tadpoles to phytotelmata, and then return to supply them with an obligate diet of nutritive eggs for about six weeks. We collected eggs, tadpoles, juveniles, and adults of O. pumilio, and detected alkaloids in all life stages. The quantity and number of alkaloids increased with frog and tadpole size. We did not detect alkaloids in the earliest stage of tadpoles, but alkaloids were detected as trace quantities in nutritive eggs and as small quantities in ovarian eggs. Tadpoles hand-reared with eggs of an alkaloid-free heterospecific frog did not contain alkaloids. Alkaloids that are sequestered from terrestrial arthropods were detected in both adults and phytotelm-dwelling tadpoles that feed solely on nutritive eggs, suggesting that this frog may be the first animal known to actively provision post-hatch offspring with chemical defenses. Finally, we provide experimental evidence that maternally derived alkaloids deter predation of tadpoles by a predatory arthropod.

  19. The relationship between poison frog chemical defenses and age, body size, and sex

    OpenAIRE

    Jeckel, Adriana M.; Saporito, Ralph A.; Grant, Taran

    2015-01-01

    Introduction Amphibians secrete a wide diversity of chemicals from skin glands as defense against predators, parasites, and pathogens. Most defensive chemicals are produced endogenously through biosynthesis, but poison frogs sequester lipophilic alkaloids from dietary arthropods. Alkaloid composition varies greatly, even among conspecific individuals collected at the same time and place, with some individuals having only a few micrograms of one or a few alkaloids and others possessing >1 mg o...

  20. From frog integument to human skin: dermatological perspectives from frog skin biology.

    Science.gov (United States)

    Haslam, Iain S; Roubos, Eric W; Mangoni, Maria Luisa; Yoshizato, Katsutoshi; Vaudry, Hubert; Kloepper, Jennifer E; Pattwell, David M; Maderson, Paul F A; Paus, Ralf

    2014-08-01

    For over a century, frogs have been studied across various scientific fields, including physiology, embryology, neuroscience, (neuro)endocrinology, ecology, genetics, behavioural science, evolution, drug development, and conservation biology. In some cases, frog skin has proven very successful as a research model, for example aiding in the study of ion transport through tight epithelia, where it has served as a model for the vertebrate distal renal tubule and mammalian epithelia. However, it has rarely been considered in comparative studies involving human skin. Yet, despite certain notable adaptations that have enabled frogs to survive in both aquatic and terrestrial environments, frog skin has many features in common with human skin. Here we present a comprehensive overview of frog (and toad) skin ontogeny, anatomy, cytology, neuroendocrinology and immunology, with special attention to its unique adaptations as well as to its similarities with the mammalian integument, including human skin. We hope to provide a valuable reference point and a source of inspiration for both amphibian investigators and mammalian researchers studying the structural and functional properties of the largest organ of the vertebrate body. © 2013 The Authors. Biological Reviews © 2013 Cambridge Philosophical Society.

  1. Environmental DNA Detection of the Golden Tree Frog (Phytotriades auratus) in Bromeliads.

    Science.gov (United States)

    Torresdal, Jack D; Farrell, Aidan D; Goldberg, Caren S

    2017-01-01

    The analysis of environmental DNA (eDNA) is a powerful, non-destructive technique for detecting rare or hard to find freshwater organisms. In this study, we investigated the effectiveness of environmental DNA analysis as a method for detecting a rare amphibian, the golden tree frog (Phytotriades auratus). These frogs are believed to live exclusively within one species of tank bromeliad, Glomeropitcairnia erectiflora, found on the highest peaks of the island of Trinidad in the West Indies. Previous survey methods for this species involved bromeliad destruction, while here we collected and analyzed water samples from discrete pools within G. erectiflora plants for species-specific DNA. We found 1) that we can identify the presence of P. auratus in the bromeliads using environmental DNA analysis, and 2) that environmental DNA evidence indicates the presence of a previously undiscovered P. auratus population, increasing the species' range from two isolated 'sky islands' to three.

  2. Environmental DNA Detection of the Golden Tree Frog (Phytotriades auratus) in Bromeliads

    Science.gov (United States)

    Torresdal, Jack D.; Farrell, Aidan D.; Goldberg, Caren S.

    2017-01-01

    The analysis of environmental DNA (eDNA) is a powerful, non-destructive technique for detecting rare or hard to find freshwater organisms. In this study, we investigated the effectiveness of environmental DNA analysis as a method for detecting a rare amphibian, the golden tree frog (Phytotriades auratus). These frogs are believed to live exclusively within one species of tank bromeliad, Glomeropitcairnia erectiflora, found on the highest peaks of the island of Trinidad in the West Indies. Previous survey methods for this species involved bromeliad destruction, while here we collected and analyzed water samples from discrete pools within G. erectiflora plants for species-specific DNA. We found 1) that we can identify the presence of P. auratus in the bromeliads using environmental DNA analysis, and 2) that environmental DNA evidence indicates the presence of a previously undiscovered P. auratus population, increasing the species’ range from two isolated ‘sky islands’ to three. PMID:28052079

  3. Tolerance of fungal infection in European water frogs exposed to Batrachochytrium dendrobatidis after experimental reduction of innate immune defenses

    Directory of Open Access Journals (Sweden)

    Woodhams Douglas C

    2012-10-01

    Full Text Available Abstract Background While emerging diseases are affecting many populations of amphibians, some populations are resistant. Determining the relative contributions of factors influencing disease resistance is critical for effective conservation management. Innate immune defenses in amphibian skin are vital host factors against a number of emerging pathogens such as ranaviruses and the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd. Adult water frogs from Switzerland (Pelophylax esculentus and P. lessonae collected in the field with their natural microbiota intact were exposed to Bd after experimental reduction of microbiota, skin peptides, both, or neither to determine the relative contributions of these defenses. Results Naturally-acquired Bd infections were detected in 10/51 P. lessonae and 4/19 P. esculentus, but no disease outbreaks or population declines have been detected at this site. Thus, this population was immunologically primed, and disease resistant. No mortality occurred during the 64 day experiment. Forty percent of initially uninfected frogs became sub-clinically infected upon experimental exposure to Bd. Reduction of both skin peptide and microbiota immune defenses caused frogs to gain less mass when exposed to Bd than frogs in other treatments. Microbiota-reduced frogs increased peptide production upon Bd infection. Ranavirus was undetectable in all but two frogs that appeared healthy in the field, but died within a week under laboratory conditions. Virus was detectable in both toe-clips and internal organs. Conclusion Intact skin microbiota reduced immune activation and can minimize subclinical costs of infection. Tolerance of Bd or ranavirus infection may differ with ecological conditions.

  4. 49 CFR 213.139 - Spring rail frogs.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Spring rail frogs. 213.139 Section 213.139..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.139 Spring rail frogs. (a) The outer edge of a wheel tread shall not contact the gage side of a spring wing rail. (b) The toe of each...

  5. Neuroendocrine regulation of frog adrenocortical cells by neurotensin

    NARCIS (Netherlands)

    Sicard, F.; D, D.E.G.; Gras, M.; Leprince, J.; Conlon, J.M.; Roubos, E.W.; Vaudry, H.; Delarue, C.

    2005-01-01

    We previously characterized the primary structure of neurotensin (NT) from an extract of the intestine of the frog Rana esculenta. In this study, we provide evidence for the involvement of NT in the neurocrine regulation of the secretory activity of frog adrenocortical cells. Immunohistochemical

  6. Coleman Revisited: School Segregation, Peers, and Frog Ponds

    Science.gov (United States)

    Goldsmith, Pat Rubio

    2011-01-01

    Students from minority segregated schools tend to achieve and attain less than similar students from White segregated schools. This study examines whether peer effects can explain this relationship using normative models and frog-pond models. Normative models (where peers become alike) suggest that minority schoolmates are a liability. Frog-pond…

  7. Infrared reflectance in leaf-sitting neotropical frogs.

    Science.gov (United States)

    Schwalm, P A; Starrett, P H; McDiarmid, R W

    1977-06-10

    Two members of the glass-frog family Centrolenidae (Centrolenella fleischmanni, C. prosoblepon) and the hylid subfamily Phyllomedusinae (Agalychnis moreletii, Pachymedusa dacnicolor) reflect near-infrared light (700 to 900 nanometers) when examined by infrared color photography. Infrared reflectance may confer adaptive advantage to these arboreal frogs both in thermoregulation and infrared cryptic coloration.

  8. Using a Phototransduction System to Monitor the Isolated Frog Heart

    Science.gov (United States)

    Stephens, Philip J.

    2015-01-01

    A simple and inexpensive method of monitoring the movement of an isolated frog heart provides comparable results to those obtained with a force transducer. A commercially available photoresistor is integrated into a Wheatstone bridge circuit, and the output signal is interfaced directly with a recording device. An excised, beating frog heart is…

  9. The use of singleplex and nested PCR to detect Batrachochytrium dendrobatidis in free-living frogs.

    Science.gov (United States)

    Coutinho, Selene Dall'Acqua; Burke, Julieta Catarina; de Paula, Catia Dejuste; Rodrigues, Miguel Trefaut; Catão-Dias, José Luiz

    2015-06-01

    Many microorganisms are able to cause diseases in amphibians, and in the past few years one of the most reported has been Batrachochytrium dendrobatidis. This fungus was first reported in Brazil in 2005; following this, other reports were made in specimens deposited in museum collections, captive and free-living frogs. The aim of this study was to compare singleplex and nested-PCR techniques to detect B. dendrobatidis in free-living and apparently healthy adult frogs from the Brazilian Atlantic Forest. The sample collection area was a protected government park, with no general entrance permitted and no management of the animals there. Swabs were taken from the skin of 107 animals without macroscopic lesions and they were maintained in ethanol p.a. Fungal DNA was extracted and identification of B. dendrobatidis was performed using singleplex and nested-PCR techniques, employing specific primers sequences. B. dendrobatidis was detected in 61/107 (57%) and 18/107 (17%) animals, respectively by nested and singleplex-PCR. Nested-PCR was statistically more sensible than the conventional for the detection of B. dendrobatidis (Chi-square = 37.1; α = 1%) and the agreement between both techniques was considered just fair (Kappa = 0.27). The high prevalence obtained confirms that these fungi occur in free-living frogs from the Brazilian Atlantic Forest with no macroscopic lesions, characterizing the state of asymptomatic carrier. We concluded that the nested-PCR technique, due to its ease of execution and reproducibility, can be recommended as one of the alternatives in epidemiological surveys to detect B. dendrobatidis in healthy free-living frog populations.

  10. The use of singleplex and nested PCR to detect Batrachochytrium dendrobatidis in free-living frogs

    Directory of Open Access Journals (Sweden)

    Selene Dall'Acqua Coutinho

    2015-06-01

    Full Text Available Many microorganisms are able to cause diseases in amphibians, and in the past few years one of the most reported has been Batrachochytrium dendrobatidis. This fungus was first reported in Brazil in 2005; following this, other reports were made in specimens deposited in museum collections, captive and free-living frogs. The aim of this study was to compare singleplex and nested-PCR techniques to detect B. dendrobatidis in free-living and apparently healthy adult frogs from the Brazilian Atlantic Forest. The sample collection area was a protected government park, with no general entrance permitted and no management of the animals there. Swabs were taken from the skin of 107 animals without macroscopic lesions and they were maintained in ethanol p.a. Fungal DNA was extracted and identification of B. dendrobatidis was performed using singleplex and nested-PCR techniques, employing specific primers sequences. B. dendrobatidis was detected in 61/107 (57% and 18/107 (17% animals, respectively by nested and singleplex-PCR. Nested-PCR was statistically more sensible than the conventional for the detection of B. dendrobatidis (Chi-square = 37.1; α = 1% and the agreement between both techniques was considered just fair (Kappa = 0.27. The high prevalence obtained confirms that these fungi occur in free-living frogs from the Brazilian Atlantic Forest with no macroscopic lesions, characterizing the state of asymptomatic carrier. We concluded that the nested-PCR technique, due to its ease of execution and reproducibility, can be recommended as one of the alternatives in epidemiological surveys to detect B. dendrobatidis in healthy free-living frog populations.

  11. 49 CFR 213.355 - Frog guard rails and guard faces; gage.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Frog guard rails and guard faces; gage. 213.355... Higher § 213.355 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs... distance between the gage line of a frog to the guard line 1 of its guard rail or guarding face, measured...

  12. The relationship between poison frog chemical defenses and age, body size, and sex.

    Science.gov (United States)

    Jeckel, Adriana M; Saporito, Ralph A; Grant, Taran

    2015-01-01

    Amphibians secrete a wide diversity of chemicals from skin glands as defense against predators, parasites, and pathogens. Most defensive chemicals are produced endogenously through biosynthesis, but poison frogs sequester lipophilic alkaloids from dietary arthropods. Alkaloid composition varies greatly, even among conspecific individuals collected at the same time and place, with some individuals having only a few micrograms of one or a few alkaloids and others possessing >1 mg of >30 alkaloids. The paucity of alkaloids in juveniles and their abundance in adults suggests that alkaloids accumulate over time; however, alkaloid diversity is highly variable among adult poison frogs and has never been studied in relation to individual age. Using skeletochronology to infer individual ages and gas chromatography-mass spectrometry and vapor phase Fourier-transform infrared spectral analysis to identify the defensive chemicals of 63 individuals, we tested the relationship between defensive chemicals and age, size, and sex in the Brazilian red-belly toad, Melanophryniscus moreirae, a poison frog that possesses both sequestered alkaloids and the biosynthesized indolealkylamine bufotenine. Adult females were, on average, older and larger than adult males. Juveniles were smaller but not necessarily younger than adults and possessed bufotenine and 18 of the 37 alkaloids found in adults. Alkaloid richness was positively related to age, but not size, whereas the quantities of sequestered alkaloids and bufotenine were positively related to size, but not age. Defensive chemicals were unrelated to sex, independent of size. The relationship between alkaloid richness and age appears to result from the gradual accumulation of alkaloids over a frog's lifetime, whereas the relationship between the quantity of defensive chemicals and size appears to be due to the greater storage capacity of larger individuals. The decoupling of age and size effects increases the amount of individual

  13. The Observation of Frog Species at State University of Malang as a Preliminary Effort on Frog Conservation

    Directory of Open Access Journals (Sweden)

    Dian Ratri Wulandari

    2013-04-01

    Full Text Available Frog is an amphibian which is widely spread around the world. Indonesia houses 450 species which represent 11% of frog species in the world. In Java Island alone, there live 42 species of frogs and toads. Frogs can be used as an environment indicator in that the presence of frog in a particular place indicates that the place stays natural and unpolluted. The 1st Campus of State University of Malang, which is located in the heart of Malang District, has been developing rapidly currently. Thus, it requires the construction of new various facilities to support its huge activities. Extensive construction can be destructive even damaging to the habitat of frog, which potentially threats the frog’s life, if it does not take the environmental impact into careful consideration. This study is aimed to identify the species of frog which survives at State University of Malang with, particularly the frog species found in 1995. Species identification was conducted by observing the morphological character. This study found that there were four species with three species remained survived in 1995; those were Duttaphrynus melanostictus, Polypedates leucomystax, and Kaloula baleta; and one new species called Rana chalconota. This study also revealed that there were four species which were extinct; those were Fejervarya cancrivora, Fejervarya limnocharis, Ingerophrynus biporcatus, and Occidoziga lima. This situation shows the decreasing amount of species from 7 to 4 within the last 17 years. This result indicates that there is a serious environmental degradation which causes the losing of frog habitats. Further research is needed to study the ecological condition changing in order to save the frog species.

  14. Further Hopping with Toads and Frogs

    OpenAIRE

    Thanatipanonda, Thotsaporn "Aek"

    2008-01-01

    We show the value of positions of the combinatorial game ``Toads and Frogs''. We present new values of starting positions. Moreover, we discuss the values of all positions with exactly one $\\Box, \\regT^{a}\\Box\\Box \\regF^{a}, \\regT^{a} \\Box \\Box \\Box \\regF \\regF \\regF,\\regT^{a}\\Box\\Box \\regF^{b}$, $\\regT^{a}\\Box\\Box\\Box \\regF^{b}$. At the end, we post five new conjectures and discuss the possible future work.

  15. Effect of magnetic fields on green color formation in frog skin

    Directory of Open Access Journals (Sweden)

    H. Kashiwagi

    2017-05-01

    Full Text Available The present work is focused on a dynamic and efficient optical control system that is made possible by investigation of the body surfaces of various animals. Specifically, we expect Japanese tree frog (Hyla japonica skin to provide a model for a flexible display device actuator mechanism. Tree frogs change body color from their original green to other colors in response to background colors. The color formation is controlled not only by chromatophores, but also by guanine microcrystals in iridophores. We collected sample microcrystals from the frog’s dorsal skin and made a model display sheet using the green skin layers. The transparent chamber that contained the crystal suspension was layered to enhance light reflection. Sheet color was observed while the angle of light incidence was varied, with and without magnetic field exposure at 0.3 T. A slight increase in red and green intensity was detected. Additionally, reflected intensity increased with increasing angle of incidence. These results indicate that the guanine crystal platelets in frog skin can efficiently switch the reflected light direction under application of a magnetic field. This in turn suggests that a several-micron-sized microcrystal of this type is a candidate material for development of flexible optical chips for ambient light control.

  16. Influence of water temperature on acetylcholinesterase activity in the pacific tree frog (Hyla regilla)

    Science.gov (United States)

    Johnson, Catherine S.; Schwarzbach, Steven E.; Henderson, John D.; Wilson, Barry W.; Tjeerdema, Ronald S.

    2005-01-01

    This investigation evaluated whether acetylcholinesterase (AChE) in Pacific tree frogs (Hyla regilla) from different geographical locations was influenced by different temperatures during early aquatic life stages, independent of pesticide exposure. Tadpoles were collected from both a California coastal pond and a Sierra Nevada mountain range pond, USA. Groups of frogs from each location were raised in temperatures representative of either the Sierra Nevada (8°C) or the coastal (19°C) location. Metamorphs from both locations raised as tadpoles at 19°C had AChE activities of 42.3 and 38.7 nm/min/mg protein, while those raised as tadpoles at 8°C had activities of 26.9 and 28.2 nm/min/mg protein. A two-way analysis of variance revealed temperature to be the significant factor in determining AChE activity (F = 22.3, p tree frogs must consider the influence of environmental temperature to enable cross-population comparisons.

  17. A consistent nomenclature of antimicrobial peptides isolated from frogs of the subfamily Phyllomedusinae.

    Science.gov (United States)

    Amiche, Mohamed; Ladram, Ali; Nicolas, Pierre

    2008-11-01

    A growing number of cationic antimicrobial peptides have been isolated from the skin of hylid frogs belonging to the Phyllomedusinae subfamily. The amino acid sequences of these peptides are currently located in several databases under identifiers with no consistent system of nomenclature to describe them. In order to provide a workable terminology for antimicrobial peptides from Phyllomedusid frogs, we have made a systematic effort to collect, analyze, and classify all the Phyllomedusid peptide sequences available in databases. We propose that frogs belonging to the Phyllomedusinae subfamily should be described by the species names set out in Amphibian Species of the World: http://research.amnh.org/herpetology/amphibia/index.php, American Museum of Natural History, New York, USA. Multiple alignments analysis of at least 80 antimicrobial peptides isolated from 12 Phyllomedusinae species were distributed in seven distinct peptide families including dermaseptin, phylloseptin, plasticin, dermatoxin, phylloxin, hyposin and orphan peptides, and will be considered as the name of the headgroup of each family. The parent peptide's name should be followed by the first upper letter of the species for orthologous peptides and publication date determines priority. For example, the abbreviation B for bicolor and H for hypochondrialis. When two species begin with the same letter, two letters in upper case should be used (the first letter followed by the second or the third letter and so on). For example, the abbreviation DI for distincta, DU for duellmani, VA for vaillanti and VN for vanzolinii. Paralogous peptides should bear letter(s) in upper case followed by numbers.

  18. Oxidative stress induced in PCB 126-exposed northern leopard frogs, Rana pipiens

    Science.gov (United States)

    Huang, Y.-W.; Hoffman, D.J.; Karasov, W.H.

    2007-01-01

    Northern leopard frogs Rana pipiens exposed to PCB 126 (3,3',4,4',5-pentachlorobiphenyl) were examined for hepatic oxidative stress. In a dose-response study, northern leopard frogs were injected intraperitoneally with either PCB 126 in corn oil (0.2, 0.7, 2.3, or 7.8 mg/kg body weight) or corn oil alone. In a time-course study, frogs received 7.8 mg/kg or corn oil alone, and were examined at 1, 2, 3, and 4 wk after dosing. Hepatic concentrations of reduced glutathione (GSH), thiobarbituric acid-reactive substances (TBARS), and total sulfhydryls (total SH), as well as activities of glutathione peroxidase (GSH-P), GSSG reductase (GSSG-R), glucose-6-phosphate dehydrogenase (G-6-PDH), and glutathione S-transferase (GSH-S-T) were measured. In the dose-response experiment, few effects were apparent 1 wk after dosing. In the time-course experiment, significant changes were observed in the 7.8-mg/kg group at 2 wk or more posttreatment. Hepatic concentrations of GSH and TBARS were higher than in corresponding controls at wk 3 and 4; the activities of GSSG-R and GSH-S-T were higher than in controls at wk 2 and 4; and the activity of G-6-PDH was increased at wk 2 and 4. These data collectively indicate that altered glutathione metabolism and oxidative stress occurred and were indicative of both toxicity and induction of protective mechanisms in frogs exposed to PCB. A similar delay in response was reported in fish and may relate to lower metabolic rate and physiological reactions in ectothermic vertebrates

  19. DNA barcoding revises a misidentification on mossy frog: new record and distribution extension of Theloderma corticale Boulenger, 1903 (Amphibia: Anura: Rhacophoridae).

    Science.gov (United States)

    Huang, Huayuan; Chen, Zening; Wei, Zhonghui; Bu, Rongping; Wu, Zhengjun

    2018-03-01

    As an endangered animal group, mossy frog (genus Theloderma) has attracted the attention of biologists and wildlife conservationists. Clarifying the taxonomic status and distribution of each species in Theloderma is important to determine the conservation status for each species, establish appropriate conservation strategies and probe the speciation process. Recently, we discovered a medium-sized species of mossy frog of the genus Theloderma in April 2015 during municipal surveys of amphibians in Dayao Mountain of Jinxiu. It was collected from the water-filled tree cavities. However, there remains some uncertainty about the species determination of the mossy frog in the Yinshan station of Dayao Mountain in Guangxi Province, China. Previously, the mossy frog in Guangxi Province was recognized as Th. kwangsiense. In order to clarify the species status of the mossy frog obtained from Guangxi, we sequenced 2414 bp of the 12S and 16S genes in the sample collected from the Dayao Mountain. Combining all the sequence in NCBI, genetic analyses from the data suggest that the sample from the Dayao Mountain is Th. corticale rather than Th. kwangsiense. It is most likely that the most previous studies had wrong species identification. And, it is the first time we use DNA barcoding to prove that the species obtained from Guangxi is a new distribution of Th. corticale.

  20. The wood frog (Rana sylvatica): a technical conservation assessment

    Science.gov (United States)

    Muths, E.; Rittmann, S.; Irwin, J.; Keinath, D.; Scherer, R.

    2005-01-01

    Overall, the wood frog (Rana sylvatica) is ranked G5, secure through most of its range (NatureServe Explorer 2002). However, it is more vulnerable in some states within the USDA Forest Service Region 2: S3 (vulnerable) in Colorado, S2 (imperiled) in Wyoming, and S1 (critically imperiled in South Dakota (NatureServe Explorer 2002); there are no records for wood frogs in Kansas or Nebraska. Primary threats to wood frog populations are habitat fragmentation (loss of area, edge effects, and isolation) and habitat loss due to anthropogenic causes (e.g., wetland draining, grazing) and natural changes as habitat succession occurs. Wood frogs are most conspicuous at breeding sites early in the spring, when snow and ice are often still present at pond margins. They tolerate frezzing and hibernate terrestrially in shallow depressions, under leaf litter, grasses, logs, or rocks (Bagdonas 1968, Bellis 1961a); there are no reports of aquatic hibernation for this species (Licht 1991, Pinder et al. 1992). Wood frogs require semi-permanent and temporary pools of natural origin and adjacent wet meadows, and landscape alterations that shorten the hydroperiod of ponds can result in catastrophic tadpole mortality. Plant communities utilized by wood frogs in the Rocky Mountains are hydric to mesic and include sedge and grass meadows, willow hummocks, aspen groves, lodgepole pine forests, and woodlands with leaf litter and/or herbaceous understory (Maslin 1947, Bellis 1961a, Roberts and Lewin 1979, Haynes and Aird 1981). Wood frogs are likely to disperse into surrounding marsh and woodlands soon after oviposition (Heatwole 1961, Haynes and Aird 1981). In the arly fall, wood frogs begin to seek hibernacula at or just below the ground surface, generally in upland forest habitat (Regosin et al. 2003). Licht (1991) demonstrated shelter-seeking behavior at 1.5 [degrees] C. Once they have concealed themselves for hibernation, wood frogs are very difficult to detecta?|

  1. Evidence of auditory insensitivity to vocalization frequencies in two frogs

    DEFF Research Database (Denmark)

    Goutte, Sandra; Mason, Matthew J; Christensen-Dalsgaard, Jakob

    2017-01-01

    The emergence and maintenance of animal communication systems requires the co-evolution of signal and receiver. Frogs and toads rely heavily on acoustic communication for coordinating reproduction and typically have ears tuned to the dominant frequency of their vocalizations, allowing discriminat......The emergence and maintenance of animal communication systems requires the co-evolution of signal and receiver. Frogs and toads rely heavily on acoustic communication for coordinating reproduction and typically have ears tuned to the dominant frequency of their vocalizations, allowing...... by their high toxicity might help to explain why calling has not yet disappeared, and that visual communication may have replaced auditory in these colourful, diurnal frogs....

  2. Complete genome sequence of frog virus 3, isolated from a strawberry poison frog (Oophaga pumilio) imported from nicaragua into the Netherlands

    NARCIS (Netherlands)

    Saucedo, Bernardo; Hughes, Joseph; Beurden, van Steven J.; Suárez, Nicolás M.; Haenen, Olga L.M.; Voorbergen-Laarman, Michal; Gröne, Andrea; Kika, Marja J.L.

    2017-01-01

    Frog virus 3 was isolated from a strawberry poison frog (Oophaga pumilio) imported from Nicaragua via Germany to the Netherlands, and its complete genome sequence was determined. Frog virus 3 isolate Op/2015/Netherlands/UU3150324001 is 107,183 bp long and has a nucleotide similarity of 98.26% to the

  3. The Homing Frog: High Homing Performance in a Territorial Dendrobatid Frog Allobates femoralis (Dendrobatidae)

    Science.gov (United States)

    Pašukonis, Andrius; Ringler, Max; Brandl, Hanja B; Mangione, Rosanna; Ringler, Eva; Hödl, Walter; Tregenza, T

    2013-01-01

    Dendrobatidae (dart-poison frogs) exhibit some of the most complex spatial behaviors among amphibians, such as territoriality and tadpole transport from terrestrial clutches to widely distributed deposition sites. In species that exhibit long-term territoriality, high homing performance after tadpole transport can be assumed, but experimental evidence is lacking, and the underlying orientation mechanisms are unknown. We conducted a field translocation experiment to test whether male Allobates femoralis, a dendrobatid frog with paternal extra-territorial tadpole transport, are capable of homing after experimental removal, as well as to quantify homing success and speed. Translocated individuals showed a very high homing success for distances up to 200 m and successfully returned from up to 400 m. We discuss the potential orientation mechanisms involved and selective forces that could have shaped this strong homing ability. PMID:25104869

  4. Ontogenetic polychromatism in marsupial frogs (Anura: Hylidae) Ontogenetic polychromatism in marsupial frogs (Anura: Hylidae)

    OpenAIRE

    Duellman William E.; Ruiz C. Pedro M.

    1986-01-01

    Color polymorphism is common in many species of marsupial frogs.  Extreme cases of pattern polymorphism are documented in four species. In Amphignathodon guentheri, Castrotheca aureomaculata, G. qriswoldi, and G. helenae juveniles are known to have only one color morph, where as two or more patterns exist in adults. In these species, polymorphism apparently develops ontogenetically. El polimorfismo cromático es común a algunas especies de sapos marsupiales. Casos extremos del modelo de polimo...

  5. Modeling synchronized calling behavior of Japanese tree frogs

    Science.gov (United States)

    Aihara, Ikkyu

    2009-07-01

    We experimentally observed synchronized calling behavior of male Japanese tree frogs Hyla japonica; namely, while isolated single frogs called nearly periodically, a pair of interacting frogs called synchronously almost in antiphase or inphase. In this study, we propose two types of phase-oscillator models on different degrees of approximations, which can quantitatively explain the phase and frequency properties in the experiment. Moreover, it should be noted that, although the second model is obtained by fitting to the experimental data of the two synchronized states, the model can also explain the transitory dynamics in the interactive calling behavior, namely, the shift from a transient inphase state to a stable antiphase state. We also discuss the biological relevance of the estimated parameter values to calling behavior of Japanese tree frogs and the possible biological meanings of the synchronized calling behavior.

  6. Final Critical Habitat for Oregon Spotted Frog (Rana pretiosa)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify, in general, the areas of FINAL critical habitat for Rana pretiosa (Oregon Spotted Frog). Maps published in the Federal Register 2016.

  7. Frog: The fast & realistic OpenGL event displayer

    Science.gov (United States)

    Quertenmont, Loïc

    2010-04-01

    FROG [1] [2] is a generic framework dedicated to visualisation of events in high energy physics experiment. It is suitable to any particular physics experiment or detector design. The code is light (cross-platform OpenGL[3] and Glut [4] libraries. Moreover, Frog does not require installation of heavy third party libraries for the visualisation. This documents describes the features and principles of Frog version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisation, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally the application of FROG for physic experiment/environement, such as Gastof, CMS, ILD, Delphes will be presented for illustration.

  8. Chromosome analysis of five Brazilian species of poison frogs ...

    Indian Academy of Sciences (India)

    Abstract. Dendrobatid frogs have undergone an extensive systematic reorganization based on recent molecular findings. The present work describes karyotypes of the Brazilian species Adelphobates castaneoticus, A. quinquevittatus, Ameerega picta, A. galactonotus and Dendrobates tinctorius which were compared to ...

  9. FROG: The Fast And Realistic OpenGL Event Displayer

    CERN Document Server

    Quertenmont, Loic

    2009-01-01

    FROG [1] [2] is a generic framework dedicated to visualisation of events in high energy experiment. It is suitable to any particular physics experiment or detector design. The code is light (< 3 MB) and fast (browsing time 20 events per second for a large High Energy Physics experiment) and can run on various operating systems, as its object-oriented structure (C++) relies on the cross-platform OPENGL [3] and GLUT [4] libraries. Moreover, FROG does not require installation of third party libraries for the visualisation. This documents describes the features and principles of FROG version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisation, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally the application of FROG for physic experiment/environement, such as Gastof, CMS, ILD, Delphes will be presented for illustration.

  10. Oregon Spotted Frog (Rana pretiosa) Monitoring at Jack Creek 2015

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset contains information from mark-recapture surveys conducted in 2015 by USGS as part of an ongoing Oregon spotted frog (Rana pretiosa) monitoring effort...

  11. California Red-Legged Frogs in coastal dune drainages (2015)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — California Red-legged Frogs (Rana draytonii) are typically regarded as inhabitants of permanent ponds, marshes, and slow-moving streams, but their ecology in other...

  12. Frog tongue surface microstructures: functional and evolutionary patterns

    Science.gov (United States)

    Gorb, Stanislav N

    2016-01-01

    Summary Frogs (Lissamphibia: Anura) use adhesive tongues to capture fast moving, elusive prey. For this, the tongues are moved quickly and adhere instantaneously to various prey surfaces. Recently, the functional morphology of frog tongues was discussed in context of their adhesive performance. It was suggested that the interaction between the tongue surface and the mucus coating is important for generating strong pull-off forces. However, despite the general notions about its importance for a successful contact with the prey, little is known about the surface structure of frog tongues. Previous studies focused almost exclusively on species within the Ranidae and Bufonidae, neglecting the wide diversity of frogs. Here we examined the tongue surface in nine different frog species, comprising eight different taxa, i.e., the Alytidae, Bombinatoridae, Megophryidae, Hylidae, Ceratophryidae, Ranidae, Bufonidae, and Dendrobatidae. In all species examined herein, we found fungiform and filiform papillae on the tongue surface. Further, we observed a high degree of variation among tongues in different frogs. These differences can be seen in the size and shape of the papillae, in the fine-structures on the papillae, as well as in the three-dimensional organization of subsurface tissues. Notably, the fine-structures on the filiform papillae in frogs comprise hair-like protrusions (Megophryidae and Ranidae), microridges (Bufonidae and Dendrobatidae), or can be irregularly shaped or absent as observed in the remaining taxa examined herein. Some of this variation might be related to different degrees of adhesive performance and may point to differences in the spectra of prey items between frog taxa. PMID:27547606

  13. Green tree frog (Hyla cinerea) and ground squirrel (Xerospermophilus spilosoma) mortality attributed to inland brevetoxin transportation at Padre Island National Seashore, Texas, 2015

    Science.gov (United States)

    Buttke, Danielle E.; Walker, Alicia; Huang, I-Shuo; Flewelling, Leanne; Lankton, Julia S.; Ballmann, Anne E.; Clapp, Travis; Lindsay, James; Zimba, Paul V.

    2017-01-01

    On 16 September 2015, a red tide (Karenia brevis) bloom impacted coastal areas of Padre Island National Seashore Park. Two days later and about 0.9 km inland, 30–40 adult green tree frogs (Hyla cinerea) were found dead after displaying tremors, weakness, labored breathing, and other signs of neurologic impairment. A rainstorm, accompanied by high winds, rough surf, and high tides, which could have aerosolized brevetoxin, occurred on the morning of the mortality event. Frog carcasses were healthy but contained significant brevetoxin in tissues. Tissue brevetoxin was also found in two dead or dying spotted ground squirrels (Xerospermophilus spilosoma) and a coyote (Canis latrans). Rainwater collected from the location of the mortality event contained brevetoxin. Mortality of green tree frog and ground squirrel mortality has not been previously attributed to brevetoxin exposure and such mortality suggested that inland toxin transport, possibly through aerosols, rainfall, or insects, may have important implications for coastal species.

  14. Green Tree Frog (Hyla cinerea) and Ground Squirrel (Xerospermophilus spilosoma) Mortality Attributed to Inland Brevetoxin Transportation at Padre Island National Seashore, Texas, 2015.

    Science.gov (United States)

    Buttke, Danielle E; Walker, Alicia; Huang, I-Shuo; Flewelling, Leanne; Lankton, Julia; Ballmann, Anne E; Clapp, Travis; Lindsay, James; Zimba, Paul V

    2017-08-22

    On 16 September 2015, a red tide (Karenia brevis) bloom impacted coastal areas of Padre Island National Seashore Park. Two days later and about 0.9 km inland, 30-40 adult green tree frogs (Hyla cinerea) were found dead after displaying tremors, weakness, labored breathing, and other signs of neurologic impairment. A rainstorm, accompanied by high winds, rough surf, and high tides, which could have aerosolized brevetoxin, occurred on the morning of the mortality event. Frog carcasses were healthy but contained significant brevetoxin in tissues. Tissue brevetoxin was also found in two dead or dying spotted ground squirrels (Xerospermophilus spilosoma) and a coyote (Canis latrans). Rainwater collected from the location of the mortality event contained brevetoxin. Mortality of green tree frog and ground squirrel mortality has not been previously attributed to brevetoxin exposure and such mortality suggested that inland toxin transport, possibly through aerosols, rainfall, or insects, may have important implications for coastal species.

  15. Pure ultrasonic communication in an endemic Bornean frog.

    Directory of Open Access Journals (Sweden)

    Victoria S Arch

    Full Text Available Huia cavitympanum, an endemic Bornean frog, is the first amphibian species known to emit exclusively ultrasonic (i.e., >20 kHz vocal signals. To test the hypothesis that these frogs use purely ultrasonic vocalizations for intraspecific communication, we performed playback experiments with male frogs in their natural calling sites. We found that the frogs respond with increased calling to broadcasts of conspecific calls containing only ultrasound. The field study was complemented by electrophysiological recordings from the auditory midbrain and by laser Doppler vibrometer measurements of the tympanic membrane's response to acoustic stimulation. These measurements revealed that the frog's auditory system is broadly tuned over high frequencies, with peak sensitivity occurring within the ultrasonic frequency range. Our results demonstrate that H. cavitympanum is the first non-mammalian vertebrate described to communicate with purely ultrasonic acoustic signals. These data suggest that further examination of the similarities and differences in the high-frequency/ultrasonic communication systems of H. cavitympanum and Odorrana tormota, an unrelated frog species that produces and detects ultrasound but does not emit exclusively ultrasonic calls, will afford new insights into the mechanisms underlying vertebrate high-frequency communication.

  16. Plasticity of peripheral auditory frequency sensitivity in Emei music frog.

    Science.gov (United States)

    Zhang, Dian; Cui, Jianguo; Tang, Yezhong

    2012-01-01

    In anurans reproductive behavior is strongly seasonal. During the spring, frogs emerge from hibernation and males vocalize for mating or advertising territories. Female frogs have the ability to evaluate the quality of the males' resources on the basis of these vocalizations. Although studies revealed that central single torus semicircularis neurons in frogs exhibit season plasticity, the plasticity of peripheral auditory sensitivity in frog is unknown. In this study the seasonally plasticity of peripheral auditory sensitivity was test in the Emei music frog Babina daunchina, by comparing thresholds and latencies of auditory brainstem responses (ABRs) evoked by tone pips and clicks in the reproductive and non-reproductive seasons. The results show that both ABR thresholds and latency differ significantly between the reproductive and non-reproductive seasons. The thresholds of tone pip evoked ABRs in the non-reproductive season increased significantly about 10 dB than those in the reproductive season for frequencies from 1 KHz to 6 KHz. ABR latencies to waveform valley values for tone pips for the same frequencies using appropriate threshold stimulus levels are longer than those in the reproductive season for frequencies from 1.5 to 6 KHz range, although from 0.2 to 1.5 KHz range it is shorter in the non-reproductive season. These results demonstrated that peripheral auditory frequency sensitivity exhibits seasonal plasticity changes which may be adaptive to seasonal reproductive behavior in frogs.

  17. Plasticity of peripheral auditory frequency sensitivity in Emei music frog.

    Directory of Open Access Journals (Sweden)

    Dian Zhang

    Full Text Available In anurans reproductive behavior is strongly seasonal. During the spring, frogs emerge from hibernation and males vocalize for mating or advertising territories. Female frogs have the ability to evaluate the quality of the males' resources on the basis of these vocalizations. Although studies revealed that central single torus semicircularis neurons in frogs exhibit season plasticity, the plasticity of peripheral auditory sensitivity in frog is unknown. In this study the seasonally plasticity of peripheral auditory sensitivity was test in the Emei music frog Babina daunchina, by comparing thresholds and latencies of auditory brainstem responses (ABRs evoked by tone pips and clicks in the reproductive and non-reproductive seasons. The results show that both ABR thresholds and latency differ significantly between the reproductive and non-reproductive seasons. The thresholds of tone pip evoked ABRs in the non-reproductive season increased significantly about 10 dB than those in the reproductive season for frequencies from 1 KHz to 6 KHz. ABR latencies to waveform valley values for tone pips for the same frequencies using appropriate threshold stimulus levels are longer than those in the reproductive season for frequencies from 1.5 to 6 KHz range, although from 0.2 to 1.5 KHz range it is shorter in the non-reproductive season. These results demonstrated that peripheral auditory frequency sensitivity exhibits seasonal plasticity changes which may be adaptive to seasonal reproductive behavior in frogs.

  18. Birds and frogs selected papers, 1990-2014

    CERN Document Server

    Dyson, Freeman J

    2015-01-01

    This book is a sequel to the volume of selected papers of Dyson up to 1990 that was published by the American Mathematical Society in 1996. The present edition comprises a collection of the most interesting writings of Freeman Dyson, all personally selected by the author, from the period 1990–2014. The five sections start off with an Introduction, followed by Talks about Science, Memoirs, Politics and History, and some Technical Papers. The most noteworthy is a lecture entitled Birds and Frogs to the American Mathematical Society that describes two kinds of mathematicians with examples from real life. Other invaluable contributions include an important tribute to C. N. Yang written for his retirement banquet at Stony Brook University, as well as a historical account of the Operational Research at RAF Bomber Command in World War II provocatively titled A Failure of Intelligence. The final section carries the open-ended question of whether any conceivable experiment could detect single gravitons to provide d...

  19. The Australasian frog family Ceratobatrachidae in China, Myanmar and Thailand: discovery of a new Himalayan forest frog clade

    Science.gov (United States)

    YAN, Fang; JIANG, Ke; WANG, Kai; JIN, Jie-Qiong; SUWANNAPOOM, Chatmongkon; LI, Cheng; Jens, V. VINDUM; Rafe, M. BROWN; CHE, Jing

    2016-01-01

    In an effort to study the systematic affinities and specieslevel phylogenetic relationships of the enigmatic anurans variably assigned to the genera Ingerana or Limnonectes (family Dicroglossidae), we collected new molecular sequence data for five species including four Himalayan taxa, Limnonectes xizangensis, Lim. medogensis, Lim. alpine, Ingerana borealis and one southeast Asian species, I. tasanae, and analyzed these together with data from previous studies involving other ostensibly related taxa. Our surprising results demonstrate unequivocally that Lim. xizangensis, Lim. medogensis and Lim. alpine form a strongly supported clade, the sister-group of the family Australasian forest frog family Ceratobatrachidae. This discovery requires an expansion of the definition of Ceratobatrachidae and represents the first record of this family in China. These three species are distinguished from the species of Ingerana and Limnonectes by the: (1) absence of interdigital webbing of the foot, (2) absence of terminal discs on fingers and toes, (3) absence of circumarginal grooves on the fingers and toes, and (4) absence of tarsal folds. Given their phylogenetic and morphological distinctiveness, we assign them to the oldest available generic name for this clade, Liurana Dubois 1987, and transfer Liurana from Dicroglossidae to the family Ceratobatrachidae. In contrast, Ingerana tasanae was found to be clustered with strong support with the recently described genus Alcalus (Ceratobatrachidae), a small clade of otherwise Sundaic species; this constitutes a new record of the family Ceratobatrachidae for Myanmar and Thailand. Finally, Ingerana borealis clustered with the "true" Ingerana (family Dicroglossidae), for which the type species is I. tenasserimensis. PMID:26828029

  20. Cadmium Contamination and Health Assessment in Frog Microhyla fissipes Living Downstream of Zinc Mining Area in Thailand

    Directory of Open Access Journals (Sweden)

    Jirarach Kitana

    2015-01-01

    Full Text Available In Mae Sot District, Tak Province, Thailand, concerns have been raised over cadmium contamination, potentially due to zinc mining activities. Although there is no report of acute toxicity on animals in this area, the impact of long-term environmental exposure to cadmium on their health are of attention. Water and sediment samples collected from two field sites (low-Cd and high-Cd sites in Mae Sot during 2008 were analyzed by GFAAS. Year round cadmium contamination in water ranged from 0.0015-0.002 mg/L in low-Cd site to 0.0019-0.0023 mg/L in high-Cd site, while higher levels were found in sediment ranged from 0.1013-0.2206 mg/kg in low-Cd site to 2.9260-3.2888 mg/kg in high-Cd site. Microhyla fissipes was collected from each habitat in 2-month interval during wet season. Detectable level of cadmium residue was found only in the frog collected from high-Cd habitat. Gravimetric analysis showed that hepatosomatic indices were significantly higher in high-Cd habitat. Histopathology showed several similar alterations in the liver, however higher number of melanomacrophage center was found in high-Cd habitat. Renosomatic indices and kidney tissue alterations were not significantly different between two sites. Reproductive health in term of gonadosomatic indices (GSI was not significantly different between male frogs from both habitats. But in the females living in high-Cd habitat, significantly lower GSI were observed. The results indicate that exposure to environmentally relevant dose of cadmium may interfere with the frog health. Using the frog as a sentinel species in this study suggests an important implication for overall health of animals/human in this area.

  1. THE MOCHE BOTANICAL FROG (La rana botánica mochica)

    National Research Council Canada - National Science Library

    Donna McClelland

    2011-01-01

    .... Fine line painted vessels and ones with low relief decoration show the Botanical Frog performing as part of a ritual involving other animals and cultivated crops, suggesting that the Botanical Frog...

  2. The first see-through frog created by breeding: description, inheritance patterns, and dermal chromatophore structure

    National Research Council Canada - National Science Library

    Sumida, Masayuki; Islam, Mohammed Mafizul; Igawa, Takeshi; Kurabayashi, Atsushi; Furukawa, Yukari; Sano, Naomi; Fujii, Tamotsu; Yoshizaki, Norio

    2016-01-01

    .... We crossed two kinds of recessive color mutant (black-eyed and gray-eyed) frogs through artificial insemination, and F2 offspring produced frogs whose skin is translucent throughout the life cycle...

  3. Prostaglandin E2 release from dermis regulates sodium permeability of frog skin epithelium

    DEFF Research Database (Denmark)

    Rytved, Klaus A.; Brodin, Birger; Nielsen, Robert

    1995-01-01

    Arachidonic acid, cAMP, epithelium, frog skin, intracellular calcium, prostaglandin E*U2, sodium transport, tight epithelium.......Arachidonic acid, cAMP, epithelium, frog skin, intracellular calcium, prostaglandin E*U2, sodium transport, tight epithelium....

  4. Population estimation of the Green and golden bell frog Litoria aurea at Port Kembla

    National Research Council Canada - National Science Library

    Goldingay, Ross L; Newell, David A

    2005-01-01

    Population estimates of the endangered Green and gold bell frog (Litoria aurea) at Port Kembla NSW, based on mark and recapture techniques suggest that two breeding sites contain more than 300 adult frogs...

  5. Frog community responses to recent American bullfrog invasions

    Directory of Open Access Journals (Sweden)

    Yiming LI, Zhunwei KE, Yihua WANG, Tim M. BLACKBURN

    2011-02-01

    Full Text Available Native species may decline quickly when confronted with an exotic species to which they are not adapted. The extent of decline may depend on the abundance of an invader and the length of time since it first arrived in the community (residence time, and the interaction between these two variables. We tested these effects using data on the effects of American bullfrog Lithobates catesbeianus invasion on native frog communities in 65 permanent lentic waters on islands in the Zhoushan Archipelago, China. We examined variation in native frog abundance and species richness in relation to features of the American bullfrog invasion, habitat disturbance, characteristics of the water body and fish communities and the presence of red swamp crayfish. Bullfrog invaded sites had lower native frog density and species richness, higher submerged vegetation cover and greater frequency of repairs to the water body than did non-invaded sites. The minimum adequate general linear mixed models showed that both native frog density and species richness were negatively related to post-metamorphosis bullfrog density, and that native frog species richness was also positively related to the vegetation cover. There was no effect on either native frog density or species richness of residence time or its interaction with bullfrog density, or of the abundance of bullfrog tadpoles. The results suggested that post-metamorphosis bullfrogs had impacts on native frog communities in the islands, and that the extents of these impacts are proportional to post-metamorphosis bullfrog density [Current Zoology 57 (1: 83–92, 2011].

  6. Frogs Call at a Higher Pitch in Traffic Noise

    Directory of Open Access Journals (Sweden)

    Kirsten M. Parris

    2009-06-01

    Full Text Available Male frogs call to attract females for mating and to defend territories from rival males. Female frogs of some species prefer lower-pitched calls, which indicate larger, more experienced males. Acoustic interference occurs when background noise reduces the active distance or the distance over which an acoustic signal can be detected. Birds are known to call at a higher pitch or frequency in urban noise, decreasing acoustic interference from low-frequency noise. Using Bayesian linear regression, we investigated the effect of traffic noise on the pitch of advertisement calls in two species of frogs, the southern brown tree frog (Litoria ewingii and the common eastern froglet (Crinia signifera. We found evidence that L. ewingii calls at a higher pitch in traffic noise, with an average increase in dominant frequency of 4.1 Hz/dB of traffic noise, and a total effect size of 123 Hz. This frequency shift is smaller than that observed in birds, but is still large enough to be detected by conspecific frogs and confer a significant benefit to the caller. Mathematical modelling predicted a 24% increase in the active distance of a L. ewingii call in traffic noise with a frequency shift of this size. Crinia signifera may also call at a higher pitch in traffic noise, but more data are required to be confident of this effect. Because frog calls are innate rather than learned, the frequency shift demonstrated by L. ewingii may represent an evolutionary adaptation to noisy conditions. The phenomenon of frogs calling at a higher pitch in traffic noise could therefore constitute an intriguing trade-off between audibility and attractiveness to potential mates.

  7. Ecology and distribution of the Florida bog frog and flatwoods salamander on Eglin Air Force Base

    OpenAIRE

    Bishop, David Christopher

    2005-01-01

    I studied the ecology and distribution of the Florida bog frog (Rana okaloosae) and flatwoods salamander (Ambystoma cingulatum) on Eglin Air Force Base in northwest Florida. I report data on the breeding ecology, population dynamics, home ranges, microhabitat, and distribution of the endemic bog frog and make comparisons to its closest relative, the bronze frog (Rana clamitans clamitans). Bog and bronze frogs occur in the same habitats and are suspected to hybridize. I investigated th...

  8. [FRancilian Oncogeriatric Group (FROG)'s focus on management of elderly patients with bladder cancer].

    Science.gov (United States)

    Ghebriou, Djamel; Avenin, Danièle; Caillet, Philippe; Mongiat-Artus, Pierre; Durdux, Catherine; Massard, Christophe; Culine, Stéphane

    2014-09-01

    Bladder cancer is diagnosed more often in the elderly. The most effective treatment strategies are mostly very aggressive and are not applicable to all patients in a very heterogeneous population. However, effective options exist to treat the most vulnerable subjects. A multidisciplinary approach including a geriatric assessment is essential for optimal adaptation of treatment. The FRancilian Oncogeriatric Group (FROG) conducted a comprehensive literature search in order to review the applicable therapeutic options according to oncological and geriatric settings. International recommendations are essential to harmonize the management of elderly patients with bladder cancer.

  9. Determination of age, longevity and age at reproduction of the frog ...

    Indian Academy of Sciences (India)

    Unknown

    to study the reproductive status of the individual frogs. (the femurs of all these frogs were also processed for skeletochronology). The remaining frogs were released. Clipped toes and limb bones were cleaned, deminera- lized in 5% nitric acid and processed for histology. Paraffin sections (8 µm) of the distal phalanx were.

  10. 49 CFR 213.143 - Frog guard rails and guard faces; gage.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Frog guard rails and guard faces; gage. 213.143... and guard faces; gage. The guard check and guard face gages in frogs shall be within the limits... frog to the guard line 1 of its guard rail or guarding face, measured across the track at right angles...

  11. Acute and chronic effects of acidic pH on four subtropical frog species

    African Journals Online (AJOL)

    We conducted acute (LC50) and chronic acid tolerance bioassays on embryos and tadpoles of four frog species found in the park, i.e., Chiromantis xerampelina (Southern Foam Nest Frog), Pyxicephalus edulis (African Bullfrog), Amietophrynus maculatus (Flat-backed Toad) and Hildebrandtia ornata (Ornate Frog), using ...

  12. 49 CFR 236.327 - Switch, movable-point frog or split-point derail.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained so...

  13. Tourism and the Conservation of Critically Endangered Frogs

    Science.gov (United States)

    Morrison, Clare; Simpkins, Clay; Castley, J. Guy; Buckley, Ralf C.

    2012-01-01

    Protected areas are critical for the conservation of many threatened species. Despite this, many protected areas are acutely underfunded, which reduces their effectiveness significantly. Tourism is one mechanism to promote and fund conservation in protected areas, but there are few studies analyzing its tangible conservation outcomes for threatened species. This study uses the 415 IUCN critically endangered frog species to evaluate the contribution of protected area tourism revenue to conservation. Contributions were calculated for each species as the proportion of geographic range inside protected areas multiplied by the proportion of protected area revenues derived from tourism. Geographic ranges were determined from IUCN Extent of Occurrence maps. Almost 60% (239) of critically endangered frog species occur in protected areas. Higher proportions of total range are protected in Nearctic, Australasian and Afrotopical regions. Tourism contributions to protected area budgets ranged from 5–100%. These financial contributions are highest for developing countries in the Afrotropical, Indomalayan and Neotropical regions. Data for both geographic range and budget are available for 201 critically endangered frog species with proportional contributions from tourism to species protection ranging from 0.8–99%. Tourism's financial contributions to critically endangered frog species protection are highest in the Afrotropical region. This study uses a coarse measure but at the global scale it demonstrates that tourism has significant potential to contribute to global frog conservation efforts. PMID:22984440

  14. Sophisticated Communication in the Brazilian Torrent Frog Hylodes japi.

    Science.gov (United States)

    de Sá, Fábio P; Zina, Juliana; Haddad, Célio F B

    2016-01-01

    Intraspecific communication in frogs plays an important role in the recognition of conspecifics in general and of potential rivals or mates in particular and therefore with relevant consequences for pre-zygotic reproductive isolation. We investigate intraspecific communication in Hylodes japi, an endemic Brazilian torrent frog with territorial males and an elaborate courtship behavior. We describe its repertoire of acoustic signals as well as one of the most complex repertoires of visual displays known in anurans, including five new visual displays. Previously unknown in frogs, we also describe a bimodal inter-sexual communication system where the female stimulates the male to emit a courtship call. As another novelty for frogs, we show that in addition to choosing which limb to signal with, males choose which of their two vocal sacs will be used for visual signaling. We explain how and why this is accomplished. Control of inflation also provides additional evidence that vocal sac movement and color must be important for visual communication, even while producing sound. Through the current knowledge on visual signaling in Neotropical torrent frogs (i.e. hylodids), we discuss and highlight the behavioral diversity in the family Hylodidae. Our findings indicate that communication in species of Hylodes is undoubtedly more sophisticated than we expected and that visual communication in anurans is more widespread than previously thought. This is especially true in tropical regions, most likely due to the higher number of species and phylogenetic groups and/or to ecological factors, such as higher microhabitat diversity.

  15. Microfungi in Drinking Water: The Role of the Frog Litoria caerulea

    Directory of Open Access Journals (Sweden)

    Larelle D. Fabbro

    2010-08-01

    Full Text Available Microfungi were recovered from all parts of a municipal water distribution system in sub-tropical Australia even though virtually no colony-forming units were recovered from the treated water as it left the treatment plant. A study was then undertaken to determine the potential sources of the microfungal population in the distribution system. Observation of frogs (Litoria caerulea using the internal infrastructure of a reservoir as diurnal sleeping places, together with observation of visible microfungal growth on their faecal pellets, led to an investigation of the possible involvement of this animal. Old faecal pellets were collected and sporulating fungal colonies growing on their surfaces were identified. Fresh faecal pellets were collected and analysed for microfungal content, and skin swabs were analysed for yeasts. It was found that the faeces and skin of L. caerulea carried large numbers of yeasts as well as spores of various filamentous fungal genera. While there are many possible sources of microfungal contamination of municipal drinking water supplies, this study has revealed that the Australian green tree frog L. caerulea is one of the important sources of filamentous microfungi and yeasts in water storage reservoirs in sub-tropical Australia where the animal is endemic.

  16. Microfungi in drinking water: the role of the frog Litoria caerulea.

    Science.gov (United States)

    Sammon, Noel B; Harrower, Keith M; Fabbro, Larelle D; Reed, Rob H

    2010-08-01

    Microfungi were recovered from all parts of a municipal water distribution system in sub-tropical Australia even though virtually no colony-forming units were recovered from the treated water as it left the treatment plant. A study was then undertaken to determine the potential sources of the microfungal population in the distribution system. Observation of frogs (Litoria caerulea) using the internal infrastructure of a reservoir as diurnal sleeping places, together with observation of visible microfungal growth on their faecal pellets, led to an investigation of the possible involvement of this animal. Old faecal pellets were collected and sporulating fungal colonies growing on their surfaces were identified. Fresh faecal pellets were collected and analysed for microfungal content, and skin swabs were analysed for yeasts. It was found that the faeces and skin of L. caerulea carried large numbers of yeasts as well as spores of various filamentous fungal genera. While there are many possible sources of microfungal contamination of municipal drinking water supplies, this study has revealed that the Australian green tree frog L. caerulea is one of the important sources of filamentous microfungi and yeasts in water storage reservoirs in sub-tropical Australia where the animal is endemic.

  17. THE PHARMACOKINETICS OF TOPICAL ITRACONAZOLE IN PANAMANIAN GOLDEN FROGS (ATELOPUS ZETEKI).

    Science.gov (United States)

    Rifkin, Amy; Visser, Marike; Barrett, Kevin; Boothe, Dawn; Bronson, Ellen

    2017-06-01

    Chytridiomycosis is caused by the fungus Batrachochytrium dendrobatidis and is one of the primary causes of the global decline in amphibian populations and specifically of the Panamanian golden frog ( Atelopus zeteki ). Itraconazole has been demonstrated to be an effective treatment for chytridiomycosis by inhibiting cytochrome P450, a major enzyme important for the structure of B. dendrobatidis zoospores' plasma membranes. However, anecdotal reports of toxicity in this and other amphibian species have been reported at the 0.01% concentration. This study is the first to determine pharmacokinetics of 0.01% and 0.001% itraconazole in the Panamanian golden frog. Frogs were bathed 10 min, euthanized, and skin, liver, and heart were collected at 0, 0.5, 1, 2, 4, 6, 8, 10, 12, 24, and 36 hr. Itraconazole concentrations were measured using high performance liquid chromatography, and the minimum inhibitory concentration (MIC) of itraconazole (0.032 μg/ml) for B. dendrobatidis was used to determine whether therapeutic concentrations were attained. Itraconazole was detected in all tissues at both concentrations, indicating systemic absorption. At the 0.01% itraconazole bath, itraconazole concentrations in all tissues exceeded the MIC at all time points, and the lack of decline until the end of the study at 36 hr precluded determining a disappearance half-life. With the 0.001% bath, itraconazole exceeded the MIC and declined with a disappearance half-life that markedly varied (14.1-1,244 min). This study augments the growing literature base on chytridiomycosis and seeks to aid in further experimental attempts to find the most-optimal treatment protocol for this disease.

  18. A perchlorate sensitive iodide transporter in frogs.

    Science.gov (United States)

    Carr, Deborah L; Carr, James A; Willis, Ray E; Pressley, Thomas A

    2008-03-01

    Nucleotide sequence comparisons have identified a gene product in the genome database of African clawed frogs (Xenopus laevis) as a probable member of the solute carrier family of membrane transporters. To confirm its identity as a putative iodide transporter, we examined the function of this sequence after heterologous expression in mammalian cells. A green monkey kidney cell line transfected with the Xenopus nucleotide sequence had significantly greater (125)I uptake than sham-transfected control cells. The uptake in carrier-transfected cells was significantly inhibited in the presence of perchlorate, a competitive inhibitor of mammalian Na(+)/iodide symporter. Tissue distributions of the sequence were also consistent with a role in iodide uptake. The mRNA encoding the carrier was found to be expressed in the thyroid gland, stomach, and kidney of tadpoles from X. laevis, as well as the bullfrog Rana catesbeiana. The ovaries of adult X. laevis also were found to express the carrier. Phylogenetic analysis suggested that the putative X. laevis iodide transporter is orthologous to vertebrate Na(+)-dependent iodide symporters. We conclude that the amphibian sequence encodes a protein that is indeed a functional Na(+)/iodide symporter in X. laevis, as well as R. catesbeiana.

  19. Assessment of heavy metals and metalloids in tissues of two frog species: Rana tigrina and Euphlyctis cyanophlyctis from industrial city Sialkot, Pakistan.

    Science.gov (United States)

    Qureshi, Irfan Zia; Kashif, Zeshan; Hashmi, Muhammad Zaffar; Su, Xiaomei; Malik, Riffat Naseem; Ullah, Kalim; Hu, Jinxing; Dawood, Muhammad

    2015-09-01

    In the present study, we investigated the concentrations of Ni, Fe, Pb, Cu, Co, Zn, Cd, Mn, and Cr in selected body tissues (liver, stomach, kidney, heart, lungs, and skeletal muscles) of two frog species: Rana tigrina and Euphlyctis cyanophlyctis captured from industrial wastewater of Sialkot city known worldwide for its tanning industry. The both frog species had darker appearance, distinctively different wet body weight, and snout-vent length. The results revealed that the heavy metal concentrations were high in the samples collected from industrial sites as compared to non-industrial sites. The different tissues of R. tigrina and E. cyanophlyctis exhibited little significant differences from two sites. The concentrations of heavy metals were more in tissues of R. tigrina as compared to E. cyanophlyctis. Mean concentration of Cd, Fe, Ni, Mn, Cu, and Cr was comparatively greater in R. tigrina, whereas Pb and Co were higher in E. cyanophlyctis. The concentration of Cu and Cd in the liver and kidney were relatively more in both species as compared to other organs. Further, the results indicated that frogs collected from industrial sites showed decreased body length and weight, and greater metal accumulation. The results will help the authorities for the conservation of these frog species which are under the influence of heavy metal contamination.

  20. Sticking under wet conditions: the remarkable attachment abilities of the torrent frog, Staurois guttatus.

    Science.gov (United States)

    Endlein, Thomas; Barnes, W Jon P; Samuel, Diana S; Crawford, Niall A; Biaw, Ang Bee; Grafe, Ulmar

    2013-01-01

    Tree frogs climb smooth surfaces utilising capillary forces arising from an air-fluid interface around their toe pads, whereas torrent frogs are able to climb in wet environments near waterfalls where the integrity of the meniscus is at risk. This study compares the adhesive capabilities of a torrent frog to a tree frog, investigating possible adaptations for adhesion under wet conditions. We challenged both frog species to cling to a platform which could be tilted from the horizontal to an upside-down orientation, testing the frogs on different levels of roughness and water flow. On dry, smooth surfaces, both frog species stayed attached to overhanging slopes equally well. In contrast, under both low and high flow rate conditions, the torrent frogs performed significantly better, even adhering under conditions where their toe pads were submerged in water, abolishing the meniscus that underlies capillarity. Using a transparent platform where areas of contact are illuminated, we measured the contact area of frogs during platform rotation under dry conditions. Both frog species not only used the contact area of their pads to adhere, but also large parts of their belly and thigh skin. In the tree frogs, the belly and thighs often detached on steeper slopes, whereas the torrent frogs increased the use of these areas as the slope angle increased. Probing small areas of the different skin parts with a force transducer revealed that forces declined significantly in wet conditions, with only minor differences between the frog species. The superior abilities of the torrent frogs were thus due to the large contact area they used on steep, overhanging surfaces. SEM images revealed slightly elongated cells in the periphery of the toe pads in the torrent frogs, with straightened channels in between them which could facilitate drainage of excess fluid underneath the pad.

  1. Sticking under wet conditions: the remarkable attachment abilities of the torrent frog, Staurois guttatus.

    Directory of Open Access Journals (Sweden)

    Thomas Endlein

    Full Text Available Tree frogs climb smooth surfaces utilising capillary forces arising from an air-fluid interface around their toe pads, whereas torrent frogs are able to climb in wet environments near waterfalls where the integrity of the meniscus is at risk. This study compares the adhesive capabilities of a torrent frog to a tree frog, investigating possible adaptations for adhesion under wet conditions. We challenged both frog species to cling to a platform which could be tilted from the horizontal to an upside-down orientation, testing the frogs on different levels of roughness and water flow. On dry, smooth surfaces, both frog species stayed attached to overhanging slopes equally well. In contrast, under both low and high flow rate conditions, the torrent frogs performed significantly better, even adhering under conditions where their toe pads were submerged in water, abolishing the meniscus that underlies capillarity. Using a transparent platform where areas of contact are illuminated, we measured the contact area of frogs during platform rotation under dry conditions. Both frog species not only used the contact area of their pads to adhere, but also large parts of their belly and thigh skin. In the tree frogs, the belly and thighs often detached on steeper slopes, whereas the torrent frogs increased the use of these areas as the slope angle increased. Probing small areas of the different skin parts with a force transducer revealed that forces declined significantly in wet conditions, with only minor differences between the frog species. The superior abilities of the torrent frogs were thus due to the large contact area they used on steep, overhanging surfaces. SEM images revealed slightly elongated cells in the periphery of the toe pads in the torrent frogs, with straightened channels in between them which could facilitate drainage of excess fluid underneath the pad.

  2. Sensory afferent segregation in three-eared frogs resemble the dominance columns observed in three-eyed frogs.

    Science.gov (United States)

    Elliott, Karen L; Houston, Douglas W; Fritzsch, Bernd

    2015-02-09

    The formation of proper sensory afferent connections during development is essential for brain function. Activity-based competition is believed to drive ocular dominance columns (ODC) in mammals and in experimentally-generated three-eyed frogs. ODC formation is thus a compromise of activity differences between two eyes and similar molecular cues. To gauge the generality of graphical map formation in the brain, we investigated the inner ear projection, known for its well-defined and early segregation of afferents from vestibular and auditory endorgans. In analogy to three eyed-frogs, we generated three-eared frogs to assess to what extent vestibular afferents from two adjacent ears could segregate. Donor ears were transplanted either in the native orientation or rotated by 90 degrees. These manipulations should result in either similar or different induced activity between both ears, respectively. Three-eared frogs with normal orientation showed normal swimming whereas those with a rotated third ear showed aberrant behaviors. Projection studies revealed that only afferents from the rotated ears segregated from those from the native ear within the vestibular nucleus, resembling the ocular dominance columns formed in three-eyed frogs. Vestibular segregation suggests that mechanisms comparable to those operating in the ODC formation of the visual system may act on vestibular projection refinements.

  3. Frog: The Fast & Realistic OpenGL Event Displayer

    CERN Document Server

    Quertenmont, Loic

    2009-01-01

    FROG [1] is a generic framework dedicated to visualisation of events in high energy experiment. It is suitable for any particular physics experiment or detector design. The code is light ($<3~\\textrm{MB}$) and fast (browsing time $\\sim20$ events per second for a large High Energy Physics experiment) and can run on various operating systems, as its object-oriented structure (C++) relies on the cross-platform OpenGL[2] and GLUT [3] libraries. Moreover, \\textsc{Frog} does not require installation of third party libraries for the visualisation. This documents describes the features and principles of FROG version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisation, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally, several examples of its current applications are presented for illustration.

  4. Lizard and frog prestin: evolutionary insight into functional changes.

    Directory of Open Access Journals (Sweden)

    Jie Tang

    Full Text Available The plasma membrane of mammalian cochlear outer hair cells contains prestin, a unique motor protein. Prestin is the fifth member of the solute carrier protein 26A family. Orthologs of prestin are also found in the ear of non-mammalian vertebrates such as zebrafish and chicken. However, these orthologs are electrogenic anion exchangers/transporters with no motor function. Amphibian and reptilian lineages represent phylogenic branches in the evolution of tetrapods and subsequent amniotes. Comparison of the peptide sequences and functional properties of these prestin orthologs offer new insights into prestin evolution. With the recent availability of the lizard and frog genome sequences, we examined amino acid sequence and function of lizard and frog prestins to determine how they are functionally and structurally different from prestins of mammals and other non-mammals. Somatic motility, voltage-dependent nonlinear capacitance (NLC, the two hallmarks of prestin function, and transport capability were measured in transfected human embryonic kidney cells using voltage-clamp and radioisotope techniques. We demonstrated that while the transport capability of lizard and frog prestin was compatible to that of chicken prestin, the NLC of lizard prestin was more robust than that of chicken's and was close to that of platypus. However, unlike platypus prestin which has acquired motor capability, lizard or frog prestin did not demonstrate motor capability. Lizard and frog prestins do not possess the same 11-amino-acid motif that is likely the structural adaptation for motor function in mammals. Thus, lizard and frog prestins appear to be functionally more advanced than that of chicken prestin, although motor capability is not yet acquired.

  5. Host Defense Peptides from Asian Frogs as Potential Clinical Therapies

    Directory of Open Access Journals (Sweden)

    Vineeth T.V. Kumar

    2015-03-01

    Full Text Available Host defense peptides (HDPs are currently major focal points of medical research as infectious microbes are gaining resistance to existing drugs. They are effective against multi-drug resistant pathogens due to their unique primary target, biological membranes, and their peculiar mode of action. Even though HDPs from 60 Asian frog species belonging to 15 genera have been characterized, research into these peptides is at a very early stage. The purpose of this review is to showcase the status of peptide research in Asia. Here we provide a summary of HDPs from Asian frogs.

  6. Neutralization of bacterial endotoxins by frog antimicrobial peptides.

    Science.gov (United States)

    Schadich, Ermin; Mason, Drusilla; Cole, Anthony L

    2013-02-01

    The ability of skin antimicrobial peptides of the southern bell frog, Litoria raniformis, to neutralize in vitro the endotoxin, proinflammatory lipopolysaccharide (LPS) complex, from two different gram-negative bacterial pathogens, human pathogen Escherichia coli (0111:B4) and frog pathogen Klebsiella pneumoniae, was investigated. The LPS neutralization activity of the natural mixture of skin antimicrobial peptides was measured using chromogenic Limulus amebocyte lysate assays. These skin antimicrobial peptides neutralized the LPSs from both pathogens at physiologically relevant concentrations (IC(50)  endotoxin agents. © 2012 The Societies and Wiley Publishing Asia Pty Ltd.

  7. Eugenol Anesthesia in African Clawed Frogs (Xenopus laevis) of Different Body Weights

    Science.gov (United States)

    Goulet, Félix; Hélie, Pierre; Vachon, Pascal

    2010-01-01

    The objective of this prospective study was to determine the duration of anesthesia in Xenopus laevis frogs of different body weights relative to exposure time in a eugenol (350 µL/L) bath. Two groups of 5 female frogs each weighing 7.5 ± 2.1 g (small frogs) or 29.2 ± 7.4 g (medium frogs) were used. The acetic acid test (AAT), withdrawal reflex, righting reflex, heart rate, and blood oxygen saturation were used to evaluate CNS depression after eugenol bath administration. No responses to the AAT, withdrawal reflex, and righting reflex were seen for 1 h (small frogs) or 0.5 h (medium frogs) after immersion in a eugenol bath for 5 or 10 min, respectively. Oxygen saturation was not affected by anesthesia, but heart rate was depressed for as long as 1 h in both groups of frogs. Surgical anesthesia evaluated by using skin and abdominal incisions revealed that small frogs were anesthetized for a maximum of 15 min compared with 30 min in medium frogs. Frogs showed no ill effects 24 h after eugenol bath administration. These results suggest that body weight is an important parameter to consider when using a eugenol bath for anesthesia of Xenopus frogs. PMID:20819393

  8. Time Series Analysis of Sound Data on Interactive Calling Behavior of Japanese Tree Frogs

    Science.gov (United States)

    Horai, Shunsuke; Aihara, Ikkyu; Aihara, Kazuyuki

    We have analyzed time series data of sound on interactive calling behavior of two male Japanese tree frogs (Hyla japonica Nihon-Ama-Gaeru). First, we have extracted two time series data mainly corresponding to respective frogs from the single time series data of calls of two frogs by the free and cross-platform sound editor Audacity. Then, we have quantitatively analyzed timing and inter-call intervals of respective frogs. Finally, we have characterized nonstationarily temporal change of the interactive calling behavior of two frogs by analysis of the cross recurrence plot. The results have shown that a pair of male frogs called in almost anti-phase synchronization after a short-term period of nearly in-phase synchronization, which implies existence of complex interactive calling behavior of two male frogs.

  9. Behavior of Japanese tree frogs under microgravity on MIR and in parabolic flight

    Science.gov (United States)

    Izumi-Kurotani, A.; Yamashita, M.; Kawasaki, Y.; Kurotani, T.; Mogami, Y.; Okuno, M.; Oketa, A.; Shiraishi, A.; Ueda, K.; Wassersug, R. J.; Naitoh, T.

    1994-08-01

    Japanese tree frogs (Hyla japonica) were flown to the space station MIR and spent eight days in orbit during December, 1990/1/. Under microgravity, their postures and behaviors were observed and recorded. On the MIR, floating frogs stretched four legs out, bent their bodies backward and expanded their abdomens. Frogs on a surface often bent their neck backward and walked backwards. This behavior was observed on parabolic flights and resembles the retching behavior of sick frogs on land- a possible indicator of motion sickness. Observations on MIR were carried out twice to investigate the frog's adaptation to space. The frequency of failure in landing after a jump decreased in the second observation period. After the frogs returned to earth, readaptation processes were observed. The frogs behaved normally as early as 2.5 hours after landing.

  10. Take time to smell the frogs: vocal sac glands of reed frogs (Anura: Hyperoliidae) contain species-specific chemical cocktails.

    Science.gov (United States)

    Starnberger, Iris; Poth, Dennis; Peram, Pardha Saradhi; Schulz, Stefan; Vences, Miguel; Knudsen, Jette; Barej, Michael F; Rödel, Mark-Oliver; Walzl, Manfred; Hödl, Walter

    2013-12-01

    Males of all reed frog species (Anura: Hyperoliidae) have a prominent, often colourful, gular patch on their vocal sac, which is particularly conspicuous once the vocal sac is inflated. Although the presence, shape, and form of the gular patch are well-known diagnostic characters for these frogs, its function remains unknown. By integrating biochemical and histological methods, we found strong evidence that the gular patch is a gland producing volatile compounds, which might be emitted while calling. Volatile compounds were confirmed by gas chromatography-mass spectrometry in the gular glands in 11 species of the hyperoliid genera Afrixalus, Heterixalus, Hyperolius, and Phlyctimantis. Comparing the gular gland contents of 17 specimens of four sympatric Hyperolius species yielded a large variety of 65 compounds in species-specific combinations. We suggest that reed frogs might use a complex combination of at least acoustic and chemical signals in species recognition and mate choice.

  11. Spread of Amphibian Chytrid Fungus across Lowland Populations of Túngara Frogs in Panamá.

    Directory of Open Access Journals (Sweden)

    Sofía Rodríguez-Brenes

    Full Text Available Chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd, is an emergent infectious disease partially responsible for worldwide amphibian population declines. The spread of Bd along highland habitats (> 500 meters above sea level, m a.s.l. of Costa Rica and Panamá is well documented and has been linked to amphibian population collapses. In contrast, data are scarce on the prevalence and dispersal of Bd in lowland habitats where amphibians may be infected but asymptomatic. Here we describe the spread (2009 to 2014 of Bd across lowland habitats east of the Panamá Canal (< 500 m a.s.l. with a focus on the Túngara frog (Physalaemus [Engystomops] pustulosus, one of the most common and abundant frog species in this region. Highland populations in western Panamá were already infected with Bd at the start of the study, which was consistent with previous studies indicating that Bd is enzootic in this region. In central Panamá, we collected the first positive samples in 2010, and by 2014, we detected Bd from remote sites in eastern Panamá (Darién National Park. We discuss the importance of studying Bd in lowland species, which may serve as potential reservoirs and agents of dispersal of Bd to highland species that are more susceptible to chytridiomycosis.

  12. Leaping frogs (Anura: Ranixalidae of the Western Ghats of India: An integrated taxonomic review

    Directory of Open Access Journals (Sweden)

    Neelesh Dahanukar

    2016-09-01

    Full Text Available Leaping frogs of the family Ranixalidae are endemic to the Western Ghats of India and are currently placed in a single genus, Indirana.  Based on specimens collected from their entire range and a comprehensive study of type material defining all known species, we propose a revised taxonomy for the leaping frogs using an integrative approach including an analysis of the mitochondrial 16S rRNA and nuclear rhodopsin genes, as well as multivariate morphometrics. Both genetic and morphological analyses suggest that the genus Indirana is paraphyletic and a distinct monophyletic group, Walkerana gen. nov is described herein.  The new genus is separated from Indirana sensu stricto by an apomorphic character state of reduced webbing, with one phalange free on the first and second toe (vs. no free phalanges, two phalanges free on the third and fifth toe (vs. one free phalange, and three phalanges free on the fourth toe (vs. 2–2½ phalanges free.  This review includes (i identification of lectotypes and redescription of three species of the genus Walkerana; (ii identification of lectotypes for Indirana beddomii and I. semipalmata and their redescription; (iii redescription of I. brachytarsus and I. gundia; and (iv descriptions of four new species, namely, I. duboisi and I. tysoni from north of the Palghat gap, and I. yadera and I. sarojamma from south of the Palghat gap; and (iv a key to the genera and species in the family Ranixalidae. 

  13. Microhabitat and Climatic Niche Change Explain Patterns of Diversification among Frog Families.

    Science.gov (United States)

    Moen, Daniel S; Wiens, John J

    2017-07-01

    A major goal of ecology and evolutionary biology is to explain patterns of species richness among clades. Differences in rates of net diversification (speciation minus extinction over time) may often explain these patterns, but the factors that drive variation in diversification rates remain uncertain. Three important candidates are climatic niche position (e.g., whether clades are primarily temperate or tropical), rates of climatic niche change among species within clades, and microhabitat (e.g., aquatic, terrestrial, arboreal). The first two factors have been tested separately in several studies, but the relative importance of all three is largely unknown. Here we explore the correlates of diversification among families of frogs, which collectively represent ∼88% of amphibian species. We assemble and analyze data on phylogeny, climate, and microhabitat for thousands of species. We find that the best-fitting phylogenetic multiple regression model includes all three types of variables: microhabitat, rates of climatic niche change, and climatic niche position. This model explains 67% of the variation in diversification rates among frog families, with arboreal microhabitat explaining ∼31%, niche rates ∼25%, and climatic niche position ∼11%. Surprisingly, we show that microhabitat can have a much stronger influence on diversification than climatic niche position or rates of climatic niche change.

  14. The unexpectedly dull tadpole of Madagascar’s largest frog, Mantidactylus guttulatus

    Directory of Open Access Journals (Sweden)

    Arne Schulze

    2016-12-01

    Full Text Available The Madagascar-endemic mantellid genus Mantidactylus contains one subclade with two described frog species characterized by very large body sizes. This subclade is classified as the subgenus Mantidactylus and is widespread in eastern and northern Madagascar, but their reproductive biology and larval stages are still unknown. We here provide a detailed description of the larvae of one species in this subgenus, M. guttulatus, on the basis of genetic assignment (16S DNA barcoding. The tadpoles were collected in the dry season from shallow waters near a stream in the Mahajanga Province in northwestern Madagascar. Their body and tail shape is remarkably generalized as typical for stream-adapted tadpoles, and the oral disc and labial keratodont row formula (4(2-4/3(1 are similar to those of other lotic mantellid frog larvae with generalized mouthparts like those in the subgenus Brygoomantis. The well-separated positions of these subgenera in the mantellid phylogeny suggest extensive homoplasy in the evolution of larval mouthpart morphology within Mantidactylus.

  15. Ontogenetic polychromatism in marsupial frogs (Anura: Hylidae Ontogenetic polychromatism in marsupial frogs (Anura: Hylidae

    Directory of Open Access Journals (Sweden)

    Duellman William E.

    1986-12-01

    Full Text Available Color polymorphism is common in many species of marsupial frogs.  Extreme cases of pattern polymorphism are documented in four species. In Amphignathodon guentheri, Castrotheca aureomaculata, G. qriswoldi, and G. helenae juveniles are known to have only one color morph, where as two or more patterns exist in adults. In these species, polymorphism apparently develops ontogenetically. El polimorfismo cromático es común a algunas especies de sapos marsupiales. Casos extremos del modelo de polimorfismo son evidentes en cuatro especies Amphignathodon guentheri, Gastrotheca aureomaculata, G. griswoldi, y G. helenae. En estas especies, se sabe que los juveniles tienen sólo un morfo de color; el polimorfismo, al parecer, se desarrolla ontogenéticamente.

  16. MicroRNA regulation in heart and skeletal muscle over the freeze-thaw cycle in the freeze tolerant wood frog.

    Science.gov (United States)

    Bansal, Saumya; Luu, Bryan E; Storey, Kenneth B

    2016-02-01

    The North American wood frog, Rana sylvatica, is one of just a few anuran species that tolerates whole body freezing during the winter and has been intensely studied to identify the biochemical adaptations that support freeze tolerance. Among these adaptations is the altered expression of many genes, making freeze-responsive changes to gene regulatory mechanisms a topic of interest. The present study focuses on the potential involvement of microRNAs as one such regulatory mechanism and aims to better understand freeze/thaw stress-induced microRNA responses in the freeze-tolerant wood frog. Using quantitative PCR, relative levels of 53 microRNAs were measured in heart and skeletal muscle of control, 24 h frozen, and 8 h thawed frogs. MicroRNAs showed tissue specific expression patterns: 21 microRNAs decreased in the heart during thawing, whereas 16 microRNAs increased during freezing stress in skeletal muscle. These findings suggest that select genes may be activated and suppressed in heart and skeletal muscle, respectively, in response to freezing. Bioinformatics analysis using the DIANA miRPath program (v.2.0) predicted that the differentially expressed microRNAs may collectively regulate tissue-specific cellular pathways to promote survival of wood frogs undergoing freezing and thawing.

  17. Measurement and Evaluation of Wear Frogs Switches ŽSR

    Directory of Open Access Journals (Sweden)

    Urda Ján

    2014-05-01

    Full Text Available This paper deals with the measurement and evaluation of wear frogs switches ZSR. One of the main problems is the oversize wear. The possibilities analysis of this problem is offered through a set of switches and monitoring of selected parameters. One of these parameters is also monitoring the vertical wear

  18. Taxonomic variation in oviposition by tailed frogs (Aschaphus spp.).

    Science.gov (United States)

    Nancy E. Karraker; David S. Pilliod; Michael J. Adams; Evelyn L. Bull; Paul Stephen Corn; Lowell V. Diller; Linda A. Dupuis; Marc P. Hayes; Blake R. Hossack; Garth R. Hodgson; Erin J. Hyde; Kirk Lohman; Bradford R. Norman; Lisa M. Ollivier; Christopher A. Pearl; Charles R. Peterson

    2006-01-01

    Tailed frogs (Ascaphus spp.) oviposit in cryptic locations in streams of the Pacific Northwest and Rocky Mountains. This aspect of their life history has restricted our understanding of their reproductive ecology. The recent split of A. montanus in the Rocky Mountains from A. truei was based on molecular...

  19. Strategies of water conservation in southern African frogs

    African Journals Online (AJOL)

    do not normally have a water conservation problem except when the water in or near which they are living dries up. Burrowing frogs (e.g. Bulo, Pyxicephalus, T017Wpterna and Brel/keps) are able to select microhabitats in the soil which reduce evaporative water loss. Burrowing may, in particular cases, be associated with ...

  20. Research on moving object detection based on frog's eyes

    Science.gov (United States)

    Fu, Hongwei; Li, Dongguang; Zhang, Xinyuan

    2008-12-01

    On the basis of object's information processing mechanism with frog's eyes, this paper discussed a bionic detection technology which suitable for object's information processing based on frog's vision. First, the bionics detection theory by imitating frog vision is established, it is an parallel processing mechanism which including pick-up and pretreatment of object's information, parallel separating of digital image, parallel processing, and information synthesis. The computer vision detection system is described to detect moving objects which has special color, special shape, the experiment indicates that it can scheme out the detecting result in the certain interfered background can be detected. A moving objects detection electro-model by imitating biologic vision based on frog's eyes is established, the video simulative signal is digital firstly in this system, then the digital signal is parallel separated by FPGA. IN the parallel processing, the video information can be caught, processed and displayed in the same time, the information fusion is taken by DSP HPI ports, in order to transmit the data which processed by DSP. This system can watch the bigger visual field and get higher image resolution than ordinary monitor systems. In summary, simulative experiments for edge detection of moving object with canny algorithm based on this system indicate that this system can detect the edge of moving objects in real time, the feasibility of bionic model was fully demonstrated in the engineering system, and it laid a solid foundation for the future study of detection technology by imitating biologic vision.

  1. Colour patterning in the skin of the reed-frog

    African Journals Online (AJOL)

    1985-12-08

    Dec 8, 1985 ... A collec1ion 01 37 Natal reed·frogs, HyperoJius marmoratus, from a single locality was studied for their dorsal colour pattems. Data were assembled on the spectrophotometry, the structure and distribution of ttie chromato· phores by means of light and electron microscopy, and the features of colour ...

  2. Elastic modulus of tree frog adhesive toe pads.

    Science.gov (United States)

    Barnes, W Jon P; Goodwyn, Pablo J Perez; Nokhbatolfoghahai, Mohsen; Gorb, Stanislav N

    2011-10-01

    Previous work using an atomic force microscope in nanoindenter mode indicated that the outer, 10- to 15-μm thick, keratinised layer of tree frog toe pads has a modulus of elasticity equivalent to silicone rubber (5-15 MPa) (Scholz et al. 2009), but gave no information on the physical properties of deeper structures. In this study, micro-indentation is used to measure the stiffness of whole toe pads of the tree frog, Litoria caerulea. We show here that tree frog toe pads are amongst the softest of biological structures (effective elastic modulus 4-25 kPa), and that they exhibit a gradient of stiffness, being stiffest on the outside. This stiffness gradient results from the presence of a dense network of capillaries lying beneath the pad epidermis, which probably has a shock absorbing function. Additionally, we compare the physical properties (elastic modulus, work of adhesion, pull-off force) of the toe pads of immature and adult frogs.

  3. Foraging behaviour in tadpoles of the bronze frog Rana temporalis ...

    Indian Academy of Sciences (India)

    The ability of bronze frog Rana temporalis tadpoles (pure or mixed parental lines) to assess the profitability of food habitats and distribute themselves accordingly was tested experimentally using a rectangular choice tank with a non-continuous input design. Food (boiled spinach) was placed at two opposite ends of the ...

  4. Genomic Sequencing of Ranaviruses Isolated from Edible Frogs (Pelophylax esculentus)

    DEFF Research Database (Denmark)

    Ariel, Ellen; Subramaniam, Kuttichantran; Imnoi, Kamonchai

    2017-01-01

    Ranaviruses were isolated from wild edible frogs (Pelophylax esculentus) during epizootics in Denmark and Italy. Phylogenomic analyses revealed that these isolates are closely related and belong to a clade of ranaviruses that includes the Andrias davidianus ranavirus (ADRV), common midwife toad...

  5. Drying kinetics of pre-osmosed fresh water frog ( Dicroglossus ...

    African Journals Online (AJOL)

    The drying kinetics of frog (Dicroglossus occipitalis) was conducted using convective oven dryer. The results were fitted into three thin-layer models; Lewis, Henderson and Page models. The constants and coefficients of the various models used were evaluated using non-linear regression methods, and the results show that ...

  6. Role of cutaneous surface fluid in frog osmoregulation

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Ramløv, Hans

    2013-01-01

    The study investigated whether evaporative water loss (EWL) in frogs stems from water diffusing through the skin or fluid secreted by mucous glands. Osmolality of cutaneous surface fluid (CSF) of Rana esculenta (Pelophylax kl. esculentus) subjected to isoproterenol or 30 °C–34 °C was 191 ± 9...

  7. Macro and Trace Element Accumulation in Edible Crabs and Frogs ...

    African Journals Online (AJOL)

    The tissue accumulation of five macroelements (Na, Mg, K, Ca, Fe) and twelve trace elements (Vd, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Pb) were assessed in the organs of the edible frogs; Xenopus laevis and Rana esculentus, and whole body of the crab, Callinestes caught from Alaro Stream Floodplain (Ibadan, ...

  8. One-tone suppression in the frog auditory nerve

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J; Jørgensen, M B

    1996-01-01

    frequencies ranged from 700 to 1200 Hz. Spontaneous activities for the fibers showing one-tone suppression ranged from 3 to 75 spikes/s. Spontaneous activities above 40 spikes/s and the phenomenon of one-tone suppression itself has not been reported previously for frogs. The population of fibers showing one...

  9. Biophysics of underwater hearing in the clawed frog, Xenopus laevis

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J; Elepfandt, A

    1995-01-01

    Anesthetized clawed frogs (Xenopus laevis) were stimulated with underwater sound and the tympanic disk vibrations were studied using laser vibrometry. The tympanic disk velocities ranged from 0.01 to 0.5 mm/s (at a sound pressure of 2 Pa) in the frequency range of 0.4-4 kHz and were 20-40 dB high...

  10. Phylogenetic relationships of the North American chorus frogs (Pseudacris: Hylidae).

    Science.gov (United States)

    Moriarty, Emily C; Cannatella, David C

    2004-02-01

    We examined phylogenetic relationships of the North American chorus frogs (Pseudacris: Hylidae) from 38 populations using 2.4 kb of 12S and 16S mtDNA to elucidate species relationships and examine congruence of previous phylogenetic hypotheses. Parsimony, maximum likelihood, and Bayesian phylogenies are consistent and reveal four strongly supported clades within Pseudacris: (1). A West Coast Clade containing regilla and cadaverina, (2). a Fat Frog Clade including ornata, streckeri, and illinoensis, (3). a Crucifer Clade consisting of crucifer and ocularis, and (4). a Trilling Frog Clade containing all other Pseudacris. Explicit hypothesis testing using parametric bootstrapping indicates that previous phylogenetic hypotheses are rejected by our sequence dataset. Within the Trilling Frog Clade, brimleyi and brachyphona form the sister group to the Nigrita Clade: nigrita, feriarum, triseriata, kalmi, clarkii, and maculata. The Nigrita Clade shows geographic division into three clades: (1). populations of maculata and triseriata west of the Mississippi River and Canadian populations, (2). southeastern US populations of feriarum and nigrita, and (3). northeastern US populations of feriarum, kalmi, and triseriata. We find that subspecific epithets for crucifer (crucifer and bartramiana) and nigrita (nigrita and verrucosa) are uninformative, therefore we discourage recognition of these subspecies. Pseudacris regilla, cadaverina, ocularis, and crucifer are maintained in Pseudacris.

  11. Evidence of auditory insensitivity to vocalization frequencies in two frogs

    DEFF Research Database (Denmark)

    Goutte, Sandra; Mason, Matthew J; Christensen-Dalsgaard, Jakob

    2017-01-01

    The emergence and maintenance of animal communication systems requires the co-evolution of signal and receiver. Frogs and toads rely heavily on acoustic communication for coordinating reproduction and typically have ears tuned to the dominant frequency of their vocalizations, allowing discriminat...

  12. Body wiping behaviors associated with cutaneous lipids in hylid tree frogs of Florida.

    Science.gov (United States)

    Barbeau, Tamatha R; Lillywhite, Harvey B

    2005-06-01

    Body wiping behavior, integumentary secretions and rates of evaporative water loss (EWL) were examined in six species of Florida tree frogs (Anura: Hylidae). Additionally, morphology of the integument and dermal glands were compared among these and one other Florida tree frog (Hyla andersonii), an arid-adapted tree frog (Phyllomedusa hypochondrialis), and a highly aquatic frog (Rana utricularia). An extra-epidermal layer of lipid and mucus, presumably secreted from dermal granular glands, was detected on the skin of all Florida hylid frogs examined. Distinct body wiping behaviors were observed in the hylid frogs, but these were less complex than those described previously in phyllomedusine frogs, which occupy arid habitats, secrete lipids onto their skin, and are regarded as relatively 'waterproof'. Florida hylids occupy seasonally arid habitats and appear to have reduced rates of EWL. The suite of traits we observed in these frogs have been previously documented in a rhacophorid tree frog from seasonally arid regions of India and likely represent an evolutionary convergent response to periodic dehydration stress. The presence of lipids that are spread by simple wiping behaviors to form an extra-epidermal water barrier may represent an early stage of the more advanced adaptations described in more waterproof arboreal frogs.

  13. Cryoprotectant Production in Freeze-Tolerant Wood Frogs Is Augmented by Multiple Freeze-Thaw Cycles.

    Science.gov (United States)

    Larson, Don J; Barnes, Brian M

    2016-01-01

    Ice nucleation across the skin of wood frogs (Lithobates sylvaticus) rapidly induces endogenous production of glucose, a cryoprotectant necessary for freeze tolerance. In laboratory studies of freeze tolerance, wood frogs are cooled slowly, often at -0.05°C h(-1), to facilitate high cryoprotectant production and survival. Under natural conditions in Alaska, however, wood frogs accumulate maximal tissue glucose concentrations while cooling at much faster rates, -0.35° to -1.6°C h(-1), and in addition undergo multiple successive freeze-thaw cycles before remaining frozen for the winter. We examined whether simulating these ecologically relevant cooling rates and repeated freeze-thaw events in captive wood frogs results in the high glucose concentrations found in naturally frozen wood frogs. We found that over successive freezing and thawing events, glucose concentrations increased stepwise in all measured tissues. Short thawing periods did not result in a statistically significant decline of glucose concentrations. Wood frogs that experienced three freeze-thaw events had fresh weight glucose concentrations that approached values found in tissues of wood frogs frozen in natural conditions. Laboratory wood frogs survive frozen for 2 mo, while wood frogs frozen under natural conditions survive frozen for up to 7 mo at temperatures below -18°C. We hypothesize that repeated freeze-thaw cycles with rapid cooling and warming rates allow for greater survival in Alaskan wood frogs through enhanced cryoprotectant production.

  14. The population decline and extinction of Darwin's frogs.

    Directory of Open Access Journals (Sweden)

    Claudio Soto-Azat

    Full Text Available Darwin's frogs (Rhinoderma darwinii and R. rufum are two species of mouth-brooding frogs from Chile and Argentina. Here, we present evidence on the extent of declines, current distribution and conservation status of Rhinoderma spp.; including information on abundance, habitat and threats to extant Darwin's frog populations. All known archived Rhinoderma specimens were examined in museums in North America, Europe and South America. Extensive surveys were carried out throughout the historical ranges of R. rufum and R. darwinii from 2008 to 2012. Literature review and location data of 2,244 archived specimens were used to develop historical distribution maps for Rhinoderma spp. Based on records of sightings, optimal linear estimation was used to estimate whether R. rufum can be considered extinct. No extant R. rufum was found and our modelling inferred that this species became extinct in 1982 (95% CI, 1980-2000. Rhinoderma darwinii was found in 36 sites. All populations were within native forest and abundance was highest in Chiloé Island, when compared with Coast, Andes and South populations. Estimated population size and density (five populations averaged 33.2 frogs/population (range, 10.2-56.3 and 14.9 frogs/100 m(2 (range, 5.3-74.1, respectively. Our results provide further evidence that R. rufum is extinct and indicate that R. darwinii has declined to a much greater degree than previously recognised. Although this species can still be found across a large part of its historical range, remaining populations are small and severely fragmented. Conservation efforts for R. darwinii should be stepped up and the species re-classified as Endangered.

  15. The complete mitochondrial genome of the relict frog Leiopelma archeyi: insights into the root of the frog Tree of Life.

    Science.gov (United States)

    Irisarri, Iker; San Mauro, Diego; Green, David M; Zardoya, Rafael

    2010-10-01

    Determining the root of the anuran Tree of Life is still a contentious and open question in frog systematics. Two genera with disjunct distributions have been traditionally considered the most basal among extant frogs: Leiopelma, which is endemic to New Zealand, and Ascaphus, which lives in North America. However, their specific phylogenetic position is rather elusive because each genus shows many autapomorphies, and together they retain many symplesiomorphic characters. Therefore, several alternative hypotheses have been proposed regarding the relative phylogenetic position of both Leiopelma and Ascaphus. In order to distinguish among these competing phylogenetic hypotheses, we sequenced the complete mitochondrial (mt) genome of Leiopelma archeyi and used it along with previously reported frog mt genomes (including that of Ascaphus truei) to infer a robust phylogeny of major anuran lineages. The reconstructed maximum likelihood and Bayesian inference phylogenies recovered identical topology, which supports the sister group relationship of Ascaphus and Leiopelma, and the placement of this clade at the base of the anuran tree. Interestingly, the mt genome of L. archeyi displays a novel gene arrangement in frog mt genomes affecting the relative position of cytochrome b, trnT, NADH dehydrogenase subunit 6, trnE, and trnP genes. The tandem duplication-random loss model of gene order change explains the origin of this novel frog mt genome arrangement, which is convergent with others reported in some fishes and salamanders. These results, together with comparative data for other available vertebrate mt genomes, provide evidence that the 5' end of the control region is a hot spot for gene order rearrangement.

  16. Pathogenicity of Aeromonas hydrophila, Klebsiella pneumoniae, and Proteus mirabilis to brown tree frogs (Litoria ewingii).

    Science.gov (United States)

    Schadich, Ermin; Cole, Anthony L J

    2010-04-01

    Bacterial dermatosepticemia, a systemic infectious bacterial disease of frogs, can be caused by several opportunistic gram-negative bacterial species including Aeromonas hydrophila, Chryseobacterium indologenes, Chryseobacterium meningosepticum, Citrobacter freundii, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, and Serratia liquifaciens. Here we determined the pathogenicity of 3 bacterial species (Aeromonas hydrophila, Klebsiella pneumoniae, and Proteus mirabilis) associated with an outbreak of fatal dermatosepticemia in New Zealand Litoria ewingii frogs. A bath challenge method was used to expose test frogs to individual bacterial species (2 x 10(7) cfu/mL in pond water); control frogs were exposed to uninfected pond water. None of the control frogs or those exposed to A. hydrophila or P. mirabilis showed any morbidity or mortality. Morbidity and mortality was 40% among frogs exposed to K. pneumonia, and the organism was reisolated from the hearts, spleens, and livers of affected animals.

  17. Glycation of wood frog (Rana sylvatica) hemoglobin and blood proteins: in vivo and in vitro studies

    Science.gov (United States)

    MacDonald, Justin A.; Degenhardt, Thorsten; Baynes, John W.; Storey, Kenneth B.

    2010-01-01

    The effects of in vivo freezing and glucose cryoprotectant on protein glycation were investigated in the wood frog, Rana sylvatica. Our studies revealed no difference in the fructoselysine content of blood plasma sampled from control, 27 h frozen and 18 h thawed wood frogs. Glycated hemoglobin (GHb) decreased slightly with 48 h freezing exposure and was below control levels after 7 d recovery, while glycated serum albumin was unchanged by 48 h freezing but did increase after 7 d of recovery. In vitro exposure of blood lysates to glucose revealed that the GHb production in wood frogs was similar to that of the rat but was lower than in leopard frogs. We conclude that wood frog hemoglobin was glycated in vitro; however, GHb production was not apparent during freezing and recovery when in vivo glucose is highly elevated. It is possible that wood frog blood proteins have different in vivo susceptibilities to glycation. PMID:19540217

  18. Frog: Asynchronous Graph Processing on GPU with Hybrid Coloring Model

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Xuanhua; Luo, Xuan; Liang, Junling; Zhao, Peng; Di, Sheng; He, Bingsheng; Jin, Hai

    2018-01-01

    GPUs have been increasingly used to accelerate graph processing for complicated computational problems regarding graph theory. Many parallel graph algorithms adopt the asynchronous computing model to accelerate the iterative convergence. Unfortunately, the consistent asynchronous computing requires locking or atomic operations, leading to significant penalties/overheads when implemented on GPUs. As such, coloring algorithm is adopted to separate the vertices with potential updating conflicts, guaranteeing the consistency/correctness of the parallel processing. Common coloring algorithms, however, may suffer from low parallelism because of a large number of colors generally required for processing a large-scale graph with billions of vertices. We propose a light-weight asynchronous processing framework called Frog with a preprocessing/hybrid coloring model. The fundamental idea is based on Pareto principle (or 80-20 rule) about coloring algorithms as we observed through masses of realworld graph coloring cases. We find that a majority of vertices (about 80%) are colored with only a few colors, such that they can be read and updated in a very high degree of parallelism without violating the sequential consistency. Accordingly, our solution separates the processing of the vertices based on the distribution of colors. In this work, we mainly answer three questions: (1) how to partition the vertices in a sparse graph with maximized parallelism, (2) how to process large-scale graphs that cannot fit into GPU memory, and (3) how to reduce the overhead of data transfers on PCIe while processing each partition. We conduct experiments on real-world data (Amazon, DBLP, YouTube, RoadNet-CA, WikiTalk and Twitter) to evaluate our approach and make comparisons with well-known non-preprocessed (such as Totem, Medusa, MapGraph and Gunrock) and preprocessed (Cusha) approaches, by testing four classical algorithms (BFS, PageRank, SSSP and CC). On all the tested applications and

  19. Frankixalus, a New Rhacophorid Genus of Tree Hole Breeding Frogs with Oophagous Tadpoles

    OpenAIRE

    Biju, S. D.; Gayani Senevirathne; Sonali Garg; Stephen Mahony; Kamei, Rachunliu G.; Ashish Thomas; Yogesh Shouche; Christopher J Raxworthy; Madhava Meegaskumbura; Ines Van Bocxlaer

    2016-01-01

    Despite renewed interest in the biogeography and evolutionary history of Old World tree frogs (Rhacophoridae), this family still includes enigmatic frogs with ambiguous phylogenetic placement. During fieldwork in four northeastern states of India, we discovered several populations of tree hole breeding frogs with oophagous tadpoles. We used molecular data, consisting of two nuclear and three mitochondrial gene fragments for all known rhacophorid genera, to investigate the phylogenetic positio...

  20. Complex and Transitive Synchronization in a Frustrated System of Calling Frogs

    OpenAIRE

    Aihara, Ikkyu; Takeda, Ryu; Mizumoto, Takeshi; Otsuka, Takuma; Takahashi, Toru; Hiroshi G. Okuno; Aihara, Kazuyuki

    2011-01-01

    This letter reports synchronization phenomena and mathematical modeling on a frustrated system of living beings, or Japanese tree frogs (Hyla japonica). While an isolated male Japanese tree frog calls nearly periodically, he can hear sounds including calls of other males. Therefore, the spontaneous calling behavior of interacting males can be understood as a system of coupled oscillators. We construct a simple but biologically reasonable model based on the experimental results of two frogs, e...

  1. Pathophysiology in mountain yellow-legged frogs (Rana muscosa during a chytridiomycosis outbreak.

    Directory of Open Access Journals (Sweden)

    Jamie Voyles

    Full Text Available The disease chytridiomycosis is responsible for declines and extirpations of amphibians worldwide. Chytridiomycosis is caused by a fungal pathogen (Batrachochytrium dendrobatidis that infects amphibian skin. Although we have a basic understanding of the pathophysiology from laboratory experiments, many mechanistic details remain unresolved and it is unknown if disease development is similar in wild amphibian populations. To gain a better understanding of chytridiomycosis pathophysiology in wild amphibian populations, we collected blood biochemistry measurements during an outbreak in mountain yellow-legged frogs (Rana muscosa in the Sierra Nevada Mountains of California. We found that pathogen load is associated with disruptions in fluid and electrolyte balance, yet is not associated with fluctuations acid-base balance. These findings enhance our knowledge of the pathophysiology of this disease and indicate that disease development is consistent across multiple species and in both laboratory and natural conditions. We recommend integrating an understanding of chytridiomycosis pathophysiology with mitigation practices to improve amphibian conservation.

  2. Phylogeography of the fanged dicroglossine frog, Limnonectes fujianensis (Anura, Ranidae), in Taiwan.

    Science.gov (United States)

    Jang-Liaw, Nian-Hong; Chou, Wen-Hao

    2011-04-01

    A phylogenetic analysis of Taiwanese fanged dicroglossine frog, Limnonectes fujianensis (Anura, Ranidae), was conducted to examine its genetic diversification using sequence data from a portion of the mitochondrial DNA (mtDNA) cytochrome b sequences. We collected genetic data from 200 individuals at 23 localities in Taiwan and three localities in China. A neighbor-joining tree of 39 haplotypes revealed two clades in Taiwan and a clade in China, each showing restricted geographical distribution. The pattern of geographical divergence suggests a single invasion into Taiwan. Divergence times between clades were inferred using molecular clock tests. The population relationship of L. fujianensis between Taiwan and mainland China, and the phylogenetic relationships with its congeners, e.g., L. bannaensis, L. fragilis and L. kuhlii, were obtained and discussed.

  3. Visual and acoustic signaling in three species of Brazilian nocturnal tree frogs (Anura, Hylidae

    Directory of Open Access Journals (Sweden)

    Luís Felipe Toledo

    2007-06-01

    Full Text Available Visual communication seems to be widespread among nocturnal anurans, however, reports of these behaviors in many Neotropical species are lacking. Therefore, we gathered information collected during several sporadic field expeditions in central and southern Brazil with three nocturnal tree frogs: Aplastodiscus perviridis, Hypsiboas albopunctatus and H. bischoffi. These species displayed various aggressive behaviors, both visual and acoustic, towards other males. For A. perviridis we described arm lifting and leg kicking; for H. albopunctatus we described the advertisement and territorial calls, visual signalizations, including a previously unreported behavior (short leg kicking, and male-male combat; and for H. bischoffiwe described the advertisement and fighting calls, toes and fingers trembling, leg lifting, and leg kicking. We speculate about the evolution of some behaviors and concluded that the use of visual signals among Neotropical anurans may be much more common than suggested by the current knowledge.

  4. The pathogen Batrachochytrium dendrobatidis disturbs the frog skin microbiome during a natural epidemic and experimental infection

    National Research Council Canada - National Science Library

    Andrea J. Jani; Cheryl J. Briggs

    2014-01-01

    ... [the chytrid fungus Batrachochytrium dendrobatidis (Bd)] on the skin-associated bacterial microbiome of the endangered frog, Rana sierrae, using a combination of population surveys and laboratory experiments...

  5. The Genome of the Western Clawed Frog Xenopus tropicalis

    Energy Technology Data Exchange (ETDEWEB)

    Hellsten, Uffe; Harland, Richard M.; Gilchrist, Michael J.; Hendrix, David; Jurka, Jerzy; Kapitonov, Vladimir; Ovcharenko, Ivan; Putnam, Nicholas H.; Shu, Shengqiang; Taher, Leila; Blitz, Ira L.; Blumberg, Bruce; Dichmann, Darwin S.; Dubchak, Inna; Amaya, Enrique; Detter, John C.; Fletcher, Russell; Gerhard, Daniela S.; Goodstein, David; Graves, Tina; Grigoriev, Igor V.; Grimwood, Jane; Kawashima, Takeshi; Lindquist, Erika; Lucas, Susan M.; Mead, Paul E.; Mitros, Therese; Ogino, Hajime; Ohta, Yuko; Poliakov, Alexander V.; Pollet, Nicolas; Robert, Jacques; Salamov, Asaf; Sater, Amy K.; Schmutz, Jeremy; Terry, Astrid; Vize, Peter D.; Warren, Wesley C.; Wells, Dan; Wills, Andrea; Wilson, Richard K.; Zimmerman, Lyle B.; Zorn, Aaron M.; Grainger, Robert; Grammer, Timothy; Khokha, Mustafa K.; Richardson, Paul M.; Rokhsar, Daniel S.

    2009-10-01

    The western clawed frog Xenopus tropicalis is an important model for vertebrate development that combines experimental advantages of the African clawed frog Xenopus laevis with more tractable genetics. Here we present a draft genome sequence assembly of X. tropicalis. This genome encodes over 20,000 protein-coding genes, including orthologs of at least 1,700 human disease genes. Over a million expressed sequence tags validated the annotation. More than one-third of the genome consists of transposable elements, with unusually prevalent DNA transposons. Like other tetrapods, the genome contains gene deserts enriched for conserved non-coding elements. The genome exhibits remarkable shared synteny with human and chicken over major parts of large chromosomes, broken by lineage-specific chromosome fusions and fissions, mainly in the mammalian lineage.

  6. Effect of cattle exclosures on Columbia Spotted Frog abundance

    Science.gov (United States)

    Adams, Michael J.; Pearl, Christopher; Chambert, Thierry; Mccreary, Brome; Galvan, Stephanie; Rowe, Jennifer

    2018-01-01

    Livestock grazing is an important land use in the western USA and can have positive or negative effects on amphibians. Columbia Spotted Frog (Rana luteiventris) often use ponds that provide water for cattle. We conducted a long-term manipulative study on US Forest Service land in northeastern Oregon to determine the effects of full and partial exclosures that limited cattle access to ponds used by frogs. We found weak evidence of a short-term increase in abundance that did not differ between full and partial exclosures and that diminished with continuing exclusion of cattle. The benefit of exclosures was small relative to the overall decline in breeding numbers that we documented. This suggests that some protection can provide a short-term boost to populations.

  7. Nanoscale friction and adhesion of tree frog toe pads.

    Science.gov (United States)

    Kappl, Michael; Kaveh, Farzaneh; Barnes, W Jon P

    2016-05-11

    Tree frogs have become an object of interest in biomimetics due to their ability to cling to wet and slippery surfaces. In this study, we have investigated the adhesion and friction behavior of toe pads of White's tree frog (Litoria caerulea) using atomic force microscopy (AFM) in an aqueous medium. Facilitating special types of AFM probes with radii of ∼400 nm and ∼13 μm, we were able to sense the frictional response without damaging the delicate nanopillar structures of the epithelial cells. While we observed no significant adhesion between both types of probes and toe pads in wet conditions, frictional forces under such conditions were very pronounced and friction coefficients amounted between 0.3 and 1.1 for the sliding friction between probes and the epithelial cell surfaces.

  8. Corneal curvatures and refractions of central American frogs.

    Science.gov (United States)

    Howland, H C; Howland, M; Giunta, A; Cronin, T W

    1997-01-01

    We employed neutralizing infrared videophotorefraction and photokeratometry to examine the manifest refractions and corneal curvatures of 21 species of anurans (frogs and toads) in five families (Dendrobatidae, Bufonidae, Centrolenidae, Leptodactylidae, and Hylidae) resident in Central America. We found that all of the anurans exhibited hyperopic refractions in air, but that the observed hyperopia was not totally explained by the small eye artefact (Glickstein & Millodot, 1970). An allometric comparison of the corneal radii of these small anurans with those of a large number of other vertebrates, inferred from ocular axial lengths, showed that their corneal radii increased significantly more rapidly with increasing body size than that of other vertebrates generally (allometric slope constants: anurans: 0.270 +/- 0.032; other vertebrates: 0.151 +/- 0.004). Among the anurans examined, nocturnal Hylids had significantly larger eyes than diurnal Dendrobatid frogs and Bufonid toads.

  9. Develop Inventory Protocols for frogs within the Region 1 Great Northern and Great Basin LCC, Protocol Development & Remote Audial Inventory

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Many refuges lack basic information on distribution of frogs, but conducting inventory surveys for frogs can be problematic. Different species breed at different...

  10. Electrophysiological evidence for an ATP-gated ion channel in the principal cells of the frog skin epithelium

    DEFF Research Database (Denmark)

    Brodin, Birger; Nielsen, Robert

    2000-01-01

    P2X receptor, Na+ absorption, Short circuit current, Cell potential, Microelectrodes, Frog skin, Cytosolic Ca2+......P2X receptor, Na+ absorption, Short circuit current, Cell potential, Microelectrodes, Frog skin, Cytosolic Ca2+...

  11. Correlation between chloride flux via the mitochondria-rich cells and transepithelial water movement in isolated frog skin (Rana esculenta)

    DEFF Research Database (Denmark)

    Nielsen, Robert

    1995-01-01

    Antidiuretic hormone; chloride transport; electroosmosis; Frog skin; Intercalated cells; Local osmosis; Mitochondria-rich cells.......Antidiuretic hormone; chloride transport; electroosmosis; Frog skin; Intercalated cells; Local osmosis; Mitochondria-rich cells....

  12. Internal pigment cells respond to external UV radiation in frogs.

    Science.gov (United States)

    Franco-Belussi, Lilian; Nilsson Sköld, Helen; de Oliveira, Classius

    2016-05-01

    Fish and amphibians have pigment cells that generate colorful skins important for signaling, camouflage, thermoregulation and protection against ultraviolet radiation (UVR). However, many animals also have pigment cells inside their bodies, on their internal organs and membranes. In contrast to external pigmentation, internal pigmentation is remarkably little studied and its function is not well known. Here, we tested genotoxic effects of UVR and its effects on internal pigmentation in a neotropical frog, Physalaemus nattereri We found increases in body darkness and internal melanin pigmentation in testes and heart surfaces and in the mesenterium and lumbar region after just a few hours of UVR exposure. The melanin dispersion in melanomacrophages in the liver and melanocytes in testes increased after UV exposure. In addition, the amount of melanin inside melanomacrophages cells also increased. Although mast cells were quickly activated by UVR, only longer UVR exposure resulted in genotoxic effects inside frogs, by increasing the frequency of micronuclei in red blood cells. This is the first study to describe systemic responses of external UVR on internal melanin pigmentation, melanomacrophages and melanocytes in frogs and thus provides a functional explanation to the presence of internal pigmentation. © 2016. Published by The Company of Biologists Ltd.

  13. Nitric oxide modulates the frog heart ventricle morphodynamics.

    Science.gov (United States)

    Acierno, Raffaele; Gattuso, Alfonsina; Guerrieri, Antonio; Mannarino, Cinzia; Amelio, Daniela; Tota, Bruno

    2008-09-01

    The aim of this work was to investigate in the avascular heart of the frog Rana esculenta the influence of nitric oxide (NO) on ventricular systolic and diastolic functions by using a novel image analysis technique. The external volume variations of the whole ventricle were monitored during the heart cycle by video acquisition(visible light) and analysed by an appropriately developed software with a specific formula for irregular convex solids. The system, which measures the rate of volume changes and the ejection fraction, directly determined the volumetric behaviour of the working frog heart after stimulation or inhibition of NOS-NOcGMP pathway. End-diastolic volume (EDVext), end-systolic volume (ESVext), contraction and relaxation velocities (dV/dtsys and dV/dtdia, respectively), stroke volume (SV) and ejection fraction (EF), were measured before and after perfusion with NOS substrate (L-arginine), NO donor (SIN-1), cGMP analogue (8-Br-cGMP),NOS inhibitors (NG-monomethyl-L-arginine, L-NMMA; L-N(5)-(1-iminoethyl)-ornithine, L-NIO; 7-Nitroindazole,7-NI) and guanylyl cyclase inhibitor (ODQ). The results showed that NO reduces ventricular systolicfunction improving diastolic filling, while NOS inhibition increases contractility impairing ventricular filling capacity. The presence of activated eNOS (p-eNOS) was morphologically documented, further supporting that the mechanical activity of the ventricular pump in frog is influenced by a tonic release of NOS-generated NO.

  14. Effects of the herbicide imazapyr on juvenile Oregon spotted frogs.

    Science.gov (United States)

    Yahnke, Amy E; Grue, Christian E; Hayes, Marc P; Troiano, Alexandra T

    2013-01-01

    Conflict between native amphibians and aquatic weed management in the Pacific Northwest is rarely recognized because most native stillwater-breeding amphibian species move upland during summer, when herbicide application to control weeds in aquatic habitats typically occurs. However, aquatic weed management may pose a risk for aquatic species present in wetlands through the summer, such as the Oregon spotted frog (OSF, Rana pretiosa), a state endangered species in Washington. Acute toxicity of herbicides used to control aquatic weeds tends to be low, but the direct effects of herbicide tank mixes on OSFs have remained unexamined. We exposed juvenile OSFs to tank mixes of the herbicide imazapyr, a surfactant, and a marker dye in a 96-h static-renewal test. The tank mix was chosen because of its low toxicity to fish and its effectiveness in aquatic weed control. Concentrations were those associated with low-volume (3.5 L/ha) and high-volume (7.0 L/ha) applications of imazapyr and a clean-water control. Following exposure, frogs were reared for two months in clean water to identify potential latent effects on growth. Endpoints evaluated included feeding behavior, growth, and body and liver condition indices. We recorded no mortalities and found no significant differences for any end point between the herbicide-exposed and clean-water control frogs. The results suggest that imazapyr use in wetland restoration poses a low risk of direct toxic effects on juvenile OSFs. Copyright © 2012 SETAC.

  15. Eugenol for anesthesia of African clawed frogs (Xenopus laevis).

    Science.gov (United States)

    Guénette, Sarah A; Hélie, Pierre; Beaudry, Francis; Vachon, Pascal

    2007-05-01

    To determine the level of anesthesia attained in Xenopus laevis frogs with eugenol at different doses and by different routes of administration. Prospective experimental trial. Sixty X. laevis nonbreeding female frogs weighing between 90 and 140 g. Three different routes of administration were tested - subcutaneous injections into the dorsal lymph sacs, topical administration using a gauze patch, and immersion in a bath containing eugenol. Following the determination of the best route of administration, the acetic acid test, the withdrawal reflex, righting reflex, heart rate, and respiratory frequency were used to evaluate central nervous system depression following eugenol bath administration. In an additional group, the response to a surgical incision of the abdominal wall was evaluated. The pharmacokinetics of eugenol were determined following bath immersion administration, and pharmacokinetic parameters were calculated following blood concentration determination by tandem liquid chromatography/mass spectrometry analyses. It was not possible to induce anethesia with subcutaneous and patch administration, independent of the eugenol dose administered. The immersion bath was the only efficacious route for anesthesia inducing surgical anesthesia for at least 30 minutes with postoperative analgesia. Histopathology of selected tissues (heart, lung, liver, kidneys, eyes) showed no evidence of lesions 24 hours following bath immersion. The elimination half-life (T(1/2)) was 4 hours. When administered as a single-bath immersion (dose 350 mg L(-1)) for 15 minutes, eugenol may serve as an effective anesthetic in X. laevis frogs for short surgical procedures.

  16. Frog meat microbiota (Lithobates catesbeianus used in infant food

    Directory of Open Access Journals (Sweden)

    Eliane Rodrigues

    2014-03-01

    Full Text Available Captive breeding of bullfrog (Lithobates catesbeianus is of great economic potential, mainly for its thighs and leather. The nutritional quality of frog meat includes properly balanced amino acids with a protein profile of high biological value, low fat and low cholesterol, and high digestibility due to its short chain molecule structure. It is recommended by doctors and nutritionists, especially for protein restricted children or malnourished children. Aiming to aggregate value to the segment and offer a product with nutritional properties that meet the need of children aged six months and above, a meat product based on the composition of frog meat was developed experimentally. To ensure raw material quality after bleaching and deboning, the microbiota present in the frog meat was determined. The analyses were performed according to Brazilian laws. It was observed that the resident and transient microbiota met the standards set by regulations. The results found were: mesophyll 4.5 x 10(4 CFU/g; Staphylococcus coagulase positive 2.0 x 10² CFU/g; negative for Salmonella sp. and Aeromonas spp. The findings indicate that the raw material showed satisfactory sanitation even in terms of family industry.

  17. An addition to the diversity of dendrobatid frogs in Venezuela: description of three new collared frogs (Anura: Dendrobatidae: Mannophryne

    Directory of Open Access Journals (Sweden)

    César Luis Barrio-Amorós

    2010-07-01

    Full Text Available Three new species of collared frogs of the genus Mannophryne are described from Venezuela. Two are newly discovered taxa from the Venezuelan Andes, whereas the third species, previously confused with M. trinitatis, is from the Caracas area in the Cordillera de la Costa. The call of the three new species and that of Mannophryne collaris are described. Taxonomic, zoogeographic, and conservation issues are discussed.

  18. Vitamin A values of wild-caught Cuban tree frogs (Osteopilus septentrionalis) and marine toads (Rhinella marina) in whole body, liver, and serum.

    Science.gov (United States)

    Sullivan, Kathleen E; Fleming, Greg; Terrell, Scott; Smith, Dustin; Ridgley, Frank; Valdes, Eduardo V

    2014-12-01

    Recent issues surrounding captive amphibians are often nutritionally related problems, such as hypovitaminosis A. Although supplementation of frogs with vitamin A is a topic of investigation, the underlying issue is understanding vitamin A metabolism in amphibian species. To develop a range of "normal" vitamin A concentrations for captive amphibians, baseline vitamin A concentrations must be established in wild amphibian species. In this study, two species, Cuban tree frogs (Osteopilus septentrionalis; n = 59) and marine toads (Rhinella marina; n = 20) were collected from the wild as part of an invasive species control program at Zoo Miami, Miami, Florida. Serum, liver, and whole body samples were analyzed for vitamin A content. The Cuban tree frogs showed higher concentrations on average of vitamin A in serum (82.8 ppb), liver (248.3 IU/g), and whole body (5474.7 IU/kg) samples compared with marine toads (60.1 ppb; 105.3 IU/g; 940.7 IU/kg, respectively), but differences were not significant (P = 0.22). What can be considered "normal" values of vitamin A concentrations across different amphibian species requires further investigation. Although all amphibians collected in this study appeared healthy, a larger sample size of animals, with known health histories and diets, may provide stronger evidence of normal expectations.

  19. Divergence of thermal physiological traits in terrestrial breeding frogs along a tropical elevational gradient.

    Science.gov (United States)

    von May, Rudolf; Catenazzi, Alessandro; Corl, Ammon; Santa-Cruz, Roy; Carnaval, Ana Carolina; Moritz, Craig

    2017-05-01

    Critical thermal limits are thought to be correlated with the elevational distribution of species living in tropical montane regions, but with upper limits being relatively invariant compared to lower limits. To test this hypothesis, we examined the variation of thermal physiological traits in a group of terrestrial breeding frogs (Craugastoridae) distributed along a tropical elevational gradient. We measured the critical thermal maximum (CT max; n = 22 species) and critical thermal minimum (CT min; n = 14 species) of frogs captured between the Amazon floodplain (250 m asl) and the high Andes (3,800 m asl). After inferring a multilocus species tree, we conducted a phylogenetically informed test of whether body size, body mass, and elevation contributed to the observed variation in CT max and CT min along the gradient. We also tested whether CT max and CT min exhibit different rates of change given that critical thermal limits (and their plasticity) may have evolved differently in response to different temperature constraints along the gradient. Variation of critical thermal traits was significantly correlated with species' elevational midpoint, their maximum and minimum elevations, as well as the maximum air temperature and the maximum operative temperature as measured across this gradient. Both thermal limits showed substantial variation, but CT min exhibited relatively faster rates of change than CT max, as observed in other taxa. Nonetheless, our findings call for caution in assuming inflexibility of upper thermal limits and underscore the value of collecting additional empirical data on species' thermal physiology across elevational gradients.

  20. Dramatic Declines of Montane Frogs in a Central African Biodiversity Hotspot.

    Directory of Open Access Journals (Sweden)

    Mareike Hirschfeld

    Full Text Available Amphibian populations are vanishing worldwide. Declines and extinctions of many populations have been attributed to chytridiomycosis, a disease induced by the pathogenic fungus Batrachochytrium dendrobatidis (Bd. In Africa, however, changes in amphibian assemblages were typically attributed to habitat change. We conducted a retrospective study utilizing field surveys from 2004-2012 of the anuran faunas on two mountains in western Cameroon, a hotspot of African amphibian diversity. The number of species detected was negatively influenced by year, habitat degradation, and elevation, and we detected a decline of certain species. Because another study in this region revealed an emergence of Bd in 2008, we screened additional recent field-collected samples and also pre-decline preserved museum specimens for the presence of Bd supporting emergence before 2008. When comparing the years before and after Bd detection, we found significantly diminished frog species richness and abundance on both mountains after Bd emergence. Our analyses suggest that this may be the first disease-driven community-level decline in anuran biodiversity in Central Africa. The disappearance of several species known to tolerate habitat degradation, and a trend of stronger declines at higher elevations, are consistent with Bd-induced declines in other regions. Not all species decreased; populations of some species remained constant, and others increased after the emergence of Bd. This variation might be explained by species-specific differences in infection probability. Increased habitat protection and Bd-mitigation strategies are needed for sustaining diverse amphibian communities such as those on Mt. Manengouba, which contains nearly half of Cameroon's frog diversity.

  1. Dramatic Declines of Montane Frogs in a Central African Biodiversity Hotspot

    Science.gov (United States)

    Hirschfeld, Mareike; Blackburn, David C.; Doherty-Bone, Thomas M.; Gonwouo, LeGrand Nono; Ghose, Sonia; Rödel, Mark-Oliver

    2016-01-01

    Amphibian populations are vanishing worldwide. Declines and extinctions of many populations have been attributed to chytridiomycosis, a disease induced by the pathogenic fungus Batrachochytrium dendrobatidis (Bd). In Africa, however, changes in amphibian assemblages were typically attributed to habitat change. We conducted a retrospective study utilizing field surveys from 2004–2012 of the anuran faunas on two mountains in western Cameroon, a hotspot of African amphibian diversity. The number of species detected was negatively influenced by year, habitat degradation, and elevation, and we detected a decline of certain species. Because another study in this region revealed an emergence of Bd in 2008, we screened additional recent field-collected samples and also pre-decline preserved museum specimens for the presence of Bd supporting emergence before 2008. When comparing the years before and after Bd detection, we found significantly diminished frog species richness and abundance on both mountains after Bd emergence. Our analyses suggest that this may be the first disease-driven community-level decline in anuran biodiversity in Central Africa. The disappearance of several species known to tolerate habitat degradation, and a trend of stronger declines at higher elevations, are consistent with Bd-induced declines in other regions. Not all species decreased; populations of some species remained constant, and others increased after the emergence of Bd. This variation might be explained by species-specific differences in infection probability. Increased habitat protection and Bd-mitigation strategies are needed for sustaining diverse amphibian communities such as those on Mt. Manengouba, which contains nearly half of Cameroon’s frog diversity. PMID:27149624

  2. Bacterial flora on Cascades frogs in the Klamath Mountains of California

    Science.gov (United States)

    Karen Pope

    2013-01-01

    Amphibians are experiencing global declines due in part to the infectious disease chytridiomycosis. Some symbiotic bacteria residents on frog skin have been shown to inhibit the growth of Batrachochytrium dendrobatitis (Bd) but few studies have attempted to fully describe the resident bacterial flora of frog skin. We cultured and sequenced 130...

  3. Phylogeography of Declining Relict and Lowland Leopard Frogs in the Desert Southwest of North America

    Science.gov (United States)

    We investigated the phylogeography of the closely related relict leopard frog (Rana onca) and lowland leopard frog (R. yavapaiensis) – two declining anurans from the warm-desert regions of southwestern North America. We used sequence data from two mitochondrial DNA genes to asses...

  4. 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

  5. An erythrocytic virus of the brazilian tree-frog, Phrynohyas venulosa

    Directory of Open Access Journals (Sweden)

    A. P. Alves de Matos

    1995-10-01

    Full Text Available Blood erythrocytes of Brazilian tree-frogs, Phrynohyas venulosa were found to frequently contain single, small, densely staining inclusions. Electron microscopy showed these to be icosahedral viral particles which measured from 250-280 nm in diameter; they were devoid of an envelope, and thus differed from previously described viruses of frog erythrocytes. The infected erythrocytes lacked a crystalline body.

  6. The critical density for the frog model is the degree of the tree

    OpenAIRE

    Johnson, Tobias; Junge, Matthew

    2016-01-01

    The frog model on the rooted $d$-ary tree changes from transient to recurrent as the number of frogs per site is increased. We prove that the location of this transition is on the same order as the degree of the tree.

  7. Complex and transitive synchronization in a frustrated system of calling frogs

    Science.gov (United States)

    Aihara, Ikkyu; Takeda, Ryu; Mizumoto, Takeshi; Otsuka, Takuma; Takahashi, Toru; Okuno, Hiroshi G.; Aihara, Kazuyuki

    2011-03-01

    This letter reports synchronization phenomena and mathematical modeling on a frustrated system of living beings, or Japanese tree frogs (Hyla japonica). While an isolated male Japanese tree frog calls nearly periodically, he can hear sounds including calls of other males. Therefore, the spontaneous calling behavior of interacting males can be understood as a system of coupled oscillators. We construct a simple but biologically reasonable model based on the experimental results of two frogs, extend the model to a system of three frogs, and theoretically predict the occurrence of rich synchronization phenomena, such as triphase synchronization and 1:2 antiphase synchronization. In addition, we experimentally verify the theoretical prediction by ethological experiments on the calling behavior of three frogs and time series analysis on recorded sound data. Note that the calling behavior of three male Japanese tree frogs is frustrated because almost perfect antiphase synchronization is robustly observed in a system of two male frogs. Thus, nonlinear dynamics of the three-frogs system should be far from trivial.

  8. Propulsive force calculations in swimming frogs II. Application of a vortex ring model to DPIV data

    NARCIS (Netherlands)

    Stamhuis, E.J.; Nauwelaerts, S.

    Frogs propel themselves by kicking water backwards using a synchronised extension of their hind limbs and webbed feet. To understand this propulsion process, we quantified the water movements and displacements resulting from swimming in the green frog Rana esculenta, applying digital particle image

  9. Population estimates for the Toiyabe population of the Columbia spotted frog (Rana luteiventris), 2004–10

    Science.gov (United States)

    Adams, Michael J.; Mellison, Chad; Galvan, Stephanie K.

    2013-01-01

    The Toiyabe population of Columbia spotted frogs (Rana luteiventris, hereafter "Toiyabe frogs") is a geographically isolated population located in central Nevada (fig. 1). The Toiyabe population is part of the Great Basin Distinct Population Segment of Columbia spotted frogs, and is a candidate for listing under the Endangered Species Act (U.S. Fish and Wildlife Service, 2011). The cluster of breeding sites in central Nevada represents the southernmost extremity of the Columbia spotted frogs' known range (Funk and others, 2008). Toiyabe frogs are known to occur in seven drainages in Nye County, Nevada: Reese River, Cow Canyon Creek, Ledbetter Canyon Creek, Cloverdale Creek, Stewart Creek, Illinois Creek, and Indian Valley Creek. Most of the Toiyabe frog population resides in the Reese River, Indian Valley Creek, and Cloverdale Creek drainages (fig. 1; Nevada Department of Wildlife, 2003). Approximately 90 percent of the Toiyabe frogs' habitat is on public land. Most of the public land habitat (95 percent) is managed by the U.S. Forest Service (USFS), while the Bureau of Land Management (BLM) manages the remainder. Additional Toiyabe frog habitat is under Yomba Shoshone Tribal management and in private ownership (Nevada Department of Wildlife, 2003). The BLM, USFS, Nevada Department of Wildlife (NDOW), Nevada Natural Heritage Program (NNHP), Nye County, and U.S Fish and Wildlife Service (USFWS) have monitored the Toiyabe population since 2004 using mark and recapture surveys (Nevada Department of Wildlife, 2004). The USFWS contracted with the U.S. Geological Survey (USGS) to produce population estimates using these data.

  10. Propulsive force calculations in swimming frogs I. A momentum-impulse approach

    NARCIS (Netherlands)

    Nauwelaerts, S; Stamhuis, EJ; Aerts, P

    Frogs are animals that are capable of locomotion in two physically different media, aquatic and terrestrial. A comparison of the kinematics of swimming frogs in a previous study revealed a difference in propulsive impulse between jumping and swimming. To explore this difference further, we

  11. [Case of cutaneous necrosis in African clawed frogs Xenopus laevis after the topical application of eugenol].

    Science.gov (United States)

    Ross, Andréanne; Guénette, Sarah Annie; Hélie, Pierre; Vachon, Pascal

    2006-11-01

    Case of cutaneous necrosis in African Clawed frogs Xenopus laevis after the topical application of eugenol. African Clawed frogs showed necrotic cutaneous lesions after a topical application of high concentrations of eugenol, an analgesic and anesthetic agent. Microscopically, ulceration of the epidermis, a loss of mucous and serous glands as well as an infiltration of inflammatory cells were observed.

  12. 78 FR 53581 - Endangered and Threatened Wildlife and Plants; Threatened Status for Oregon Spotted Frog

    Science.gov (United States)

    2013-08-29

    ... faint mask, and a light jaw stripe extends to the shoulder. Small bumps and tubercles usually cover the... the area used during the rest of the year. During the dry season (June-August), frogs moved to deeper... and the limited dispersal ability of Oregon spotted frog. For the rest of the document, we will...

  13. Histopathological changes and erythrocytic nuclear abnormalities in Iberian green frogs (Rana perezi Seoane) from a uranium mine pond

    Energy Technology Data Exchange (ETDEWEB)

    Marques, S.M. [Departamento de Biologia/Centro de Estudos do Ambiente e do Mar (CESAM), Campus de Santiago, Universidade de Aveiro, 3810-193 Aveiro (Portugal)], E-mail: s.reis.marques@gmail.com; Antunes, S.C. [Departamento de Biologia/Centro de Estudos do Ambiente e do Mar (CESAM), Campus de Santiago, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Pissarra, H. [Laboratorio de Anatomia Patologica, Centro de Investigacao Interdisciplinar em Sanidade Animal (CIISA), Faculdade de Medicina Veterinaria, U.T.L., Lisboa (Portugal); Pereira, M.L. [Departamento de Biologia/Centro de Investigacao em Materiais Ceramicos e Compositos (CICECO), Campus de Santiago, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Goncalves, F.; Pereira, R. [Departamento de Biologia/Centro de Estudos do Ambiente e do Mar (CESAM), Campus de Santiago, Universidade de Aveiro, 3810-193 Aveiro (Portugal)

    2009-01-31

    In spite of their sensitivity to anthropogenic stressors, adults of Rana perezi Seoane were found inhabiting effluent ponds from a uranium mine. Due to the presence of such organisms in this environment, it becomes of paramount importance to assess the damages induced by local contamination on these aquatic vertebrates, in order to integrate this information on a site-specific risk assessment that is being carried out in the area. To attain this purpose an ethically and statistically acceptable number of green frogs were captured in the mine pond (M) and in a pristine river (VR), a few kilometres from the mine. Bioaccumulation of metals and histopathological alterations were evaluated in the liver, kidneys, spleen, lungs and testes of the animals. Simultaneously, blood samples were collected for the evaluation of genotoxic damage on erythrocytes. Animals captured in the M pond showed significantly increased levels of Be, Al, Mn, Fe and U in the liver, as well as Pb and U in the kidney. The liver was the main target organ for the bioaccumulation of Be, Al, Fe and U. However, renal histopathologies were more severe than those of liver. The main tissue alterations recorded in animals from the mine were: a slight increase in melanomacrophagic centers (MMC) in liver, lung and kidneys; dilatation of the renal tubules lumen associated with tubular necrosis. A significantly higher number of erythrocytic abnormalities (lobed, notched and kidney shaped nuclei and micronuclei) were recorded in frogs from M than in frogs from VR, along with a significantly lower frequency of immature erythrocytes. Both observations suggested that the removal of abnormal blood cells might be compromised.

  14. Isolation of Brucella inopinata-Like Bacteria from White's and Denny's Tree Frogs.

    Science.gov (United States)

    Kimura, Masanobu; Une, Yumi; Suzuki, Michio; Park, Eun-Sil; Imaoka, Koichi; Morikawa, Shigeru

    2017-05-01

    Brucella inopinata strain BO1 and B. sp. strain BO2 isolated from human patients, respectively, are genetically different from classical Brucella species. We isolated bacteria of the genus Brucella from two species of wild-caught tropical frogs kept in the facilities in Japan: White's tree frog, which inhabits Oceania, and Denny's tree frog, which inhabits Southeast Asia. Phylogenetic analyses based on 16S rRNA and recA gene sequences and multilocus sequence analysis showed that two isolates of Brucella spp. showed significant similarity to BO1, BO2, and the isolates from other wild-caught frogs. These results suggest that a variety of frog species are susceptible to a novel clade of Brucella bacteria, including B. inopinata.

  15. The brain tryptophan hydroxylase activity in the sleep-like states in frog.

    Science.gov (United States)

    Kulikov, A V; Karmanova, I G; Kozlachkova, E Y; Voronova, I P; Popova, N K

    1994-10-01

    The activity of the rate-limiting enzyme of serotonin biosynthesis, tryptophan hydroxylase, was determined in the brain stem in active awake frogs, and frogs in three sleep-like states: with plastic muscle tone (SLS-1), with rigid muscle tone (SLS-2), and with relaxed muscle tone (SLS-3). Significant decrease in the enzyme activity has been found in frogs in SLS-1 and SLS-2 compared to awake animals. The development in frogs a cataleptic-like immobility after treating the animals with rhythmic lighting was accompanied with a decrease in the brain tryptophan hydroxylase activity. These results provide strong evidence for the involvement of the brain serotonin in frogs in the control of evolutionary ancient sleep-like states, probably by the regulation of muscle tone.

  16. Frankixalus, a New Rhacophorid Genus of Tree Hole Breeding Frogs with Oophagous Tadpoles.

    Science.gov (United States)

    Biju, S D; Senevirathne, Gayani; Garg, Sonali; Mahony, Stephen; Kamei, Rachunliu G; Thomas, Ashish; Shouche, Yogesh; Raxworthy, Christopher J; Meegaskumbura, Madhava; Van Bocxlaer, Ines

    2016-01-01

    Despite renewed interest in the biogeography and evolutionary history of Old World tree frogs (Rhacophoridae), this family still includes enigmatic frogs with ambiguous phylogenetic placement. During fieldwork in four northeastern states of India, we discovered several populations of tree hole breeding frogs with oophagous tadpoles. We used molecular data, consisting of two nuclear and three mitochondrial gene fragments for all known rhacophorid genera, to investigate the phylogenetic position of these new frogs. Our analyses identify a previously overlooked, yet distinct evolutionary lineage of frogs that warrants recognition as a new genus and is here described as Frankixalus gen. nov. This genus, which contains the enigmatic 'Polypedates' jerdonii described by Günther in 1876, forms the sister group of a clade containing Kurixalus, Pseudophilautus, Raorchestes, Mercurana and Beddomixalus. The distinctiveness of this evolutionary lineage is also corroborated by the external morphology of adults and tadpoles, adult osteology, breeding ecology, and life history features.

  17. Frankixalus, a New Rhacophorid Genus of Tree Hole Breeding Frogs with Oophagous Tadpoles.

    Directory of Open Access Journals (Sweden)

    S D Biju

    Full Text Available Despite renewed interest in the biogeography and evolutionary history of Old World tree frogs (Rhacophoridae, this family still includes enigmatic frogs with ambiguous phylogenetic placement. During fieldwork in four northeastern states of India, we discovered several populations of tree hole breeding frogs with oophagous tadpoles. We used molecular data, consisting of two nuclear and three mitochondrial gene fragments for all known rhacophorid genera, to investigate the phylogenetic position of these new frogs. Our analyses identify a previously overlooked, yet distinct evolutionary lineage of frogs that warrants recognition as a new genus and is here described as Frankixalus gen. nov. This genus, which contains the enigmatic 'Polypedates' jerdonii described by Günther in 1876, forms the sister group of a clade containing Kurixalus, Pseudophilautus, Raorchestes, Mercurana and Beddomixalus. The distinctiveness of this evolutionary lineage is also corroborated by the external morphology of adults and tadpoles, adult osteology, breeding ecology, and life history features.

  18. Inventory of frog species in the South Carolina Sandhills with a focus on the pine barrens treefrog and the gopher frog

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Tabular data consists of site specific locations of sampling points on Carolina Sandhills NWR for determination of frog species and more specifically sites with Pine...

  19. Which frog's legs do froggies eat? The use of DNA barcoding for identification of deep frozen frog legs (Dicroglossidae, Amphibia commercialized in France

    Directory of Open Access Journals (Sweden)

    Annemarie Ohler

    2017-02-01

    Full Text Available Several millions frogs captured in the wild in Indonesia are sold for food yearly in French supermarkets, as deep frozen frog legs. They are commercialized as Rana macrodon, but up to 15 look-alike species might also be concerned by this trade. From December 2012 to May 2013, we bought 209 specimens of deep frozen frog legs, and identified them through a barcoding approach based on the 16S gene. Our results show that 206 out of the 209 specimens belong to Fejervarya cancrivora, two to Limnonectes macrodon and one to F. moodiei. Thus only 0.96 % of the frogs were correctly identified. Unless misclassification was intentional, it seems that Indonesian frog leg exporters are not able to discriminate between the species. The quasi absence of L. macrodon in our samples might be an indication of its rarity, confirming that its natural populations are declining rapidly, in agreement with its “vulnerable” status according to the IUCN Red List. Our results show that the genetic and morphological diversity of the frogs in trade is much higher than the genetic and morphological diversity measured so far by scientific studies. These results underline the need for large scale studies to assess the status of wild populations.

  20. Taxonomy Icon Data: Japanese tree frog [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available Japanese tree frog Hyla japonica Chordata/Vertebrata/Amphibia Hyla_japonica_L.png Hyla_japon...ica_NL.png Hyla_japonica_S.png Hyla_japonica_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Hyla+japon...ica&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Hyla+japonica&t=NL http://biosciencedbc....jp/taxonomy_icon/icon.cgi?i=Hyla+japonica&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Hyla+japon

  1. Tactical reproductive parasitism via larval cannibalism in Peruvian poison frogs

    Science.gov (United States)

    Brown, Jason L.; Morales, Victor; Summers, Kyle

    2008-01-01

    We report an unusual example of reproductive parasitism in amphibians. Dendrobates variabilis, an Amazonian poison frog, oviposits at the surface of the water in small pools in plants and deposits tadpoles within the pools. Tadpoles are highly cannibalistic and consume young tadpoles if they are accessible. Deposition of embryos and tadpoles in the same pool is common. Genetic analyses indicate that tadpoles are frequently unrelated to embryos in the same pool. A pool choice experiment in the field demonstrated that males carrying tadpoles prefer to place them in pools with embryos, facilitating reproductive parasitism via cannibalism. PMID:19042178

  2. Membrane interactions of antimicrobial peptides from Australian frogs.

    Science.gov (United States)

    Fernandez, David I; Gehman, John D; Separovic, Frances

    2009-08-01

    The membrane interactions of four antimicrobial peptides, aurein 1.2, citropin 1.1, maculatin 1.1 and caerin 1.1, isolated from Australian tree frogs, are reviewed. All four peptides are amphipathic alpha-helices with a net positive charge and range in length from 13 to 25 residues. Despite several similar sequence characteristics, these peptides compromise the integrity of model membrane bilayers via different mechanisms; the shorter peptides exhibit a surface interaction mechanism while the longer peptides may form pores in membranes.

  3. From transience to recurrence with Poisson tree frogs

    OpenAIRE

    Hoffman, Christopher; Johnson, Tobias; Junge, Matthew

    2016-01-01

    Consider the following interacting particle system on the $d$-ary tree, known as the frog model: Initially, one particle is awake at the root and i.i.d. Poisson many particles are sleeping at every other vertex. Particles that are awake perform simple random walks, awakening any sleeping particles they encounter. We prove that there is a phase transition between transience and recurrence as the initial density of particles increases, and we give the order of the transition up to a logarithmic...

  4. Taxonomy Icon Data: Western clawed frog [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available Western clawed frog Xenopus tropicalis Chordata/Vertebrata/Amphibia Xenopus_tropicalis_L.png Xenopus_tropica...lis_NL.png Xenopus_tropicalis_S.png Xenopus_tropicalis_NS.png http://biosciencedbc....jp/taxonomy_icon/icon.cgi?i=Xenopus+tropicalis&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Xenopus+tropical...is&t=NL http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Xenopus+tropical...is&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Xenopus+tropicalis&t=NS http://togodb.biosciencedbc.jp/togodb/view/taxonomy_icon_comment_en?species_id=137 ...

  5. Analysis of veterinary drug residues in frog legs and other aquacultured species using liquid chromatography quadrupole time-of-flight mass spectrometry.

    Science.gov (United States)

    Turnipseed, Sherri B; Clark, Susan B; Storey, Joseph M; Carr, Justin R

    2012-05-09

    A liquid chromatography quadrupole time-of-flight (Q-TOF) mass spectrometry method was developed to analyze veterinary drug residues in frog legs and other aquacultured species. Samples were extracted using a procedure based on a method developed for the analysis of fluoroquinolones (FQs) in fish. Briefly, the tissue was extracted with dilute acetic acid and acetonitrile with added sodium chloride. After centrifugation, the extracts were evaporated and reconstituted in mobile phase. A molecular weight cutoff filter was used to clean up the final extract. A set of target compounds, including trimethoprim, sulfamethoxazole, chloramphenicol, quinolones, and FQs, was used to validate the method. Screening of residues was accomplished by collecting TOF (MS¹) data and comparing the accurate mass and retention times of compounds to a database containing information for veterinary drugs. An evaluation of the MS data in fortified frog legs indicated that the target compounds could be consistently detected at the level of concern. The linearity and recoveries from matrix were evaluated for these analytes to estimate the amount of residue present. MS/MS data were also generated from precursor ions, and the mass accuracy of the product ions for each compound was compared to theoretical values. When the method was used to analyze imported frog legs, many of these residues were found in the samples, often in combination and at relatively high concentrations (>10 ng/g). The data from these samples were also evaluated for nontarget analytes such as residue metabolites and other chemotherapeutics.

  6. Morphological description of Cosmocerca sp. (Nematoda: Cosmocerdidae) from the Mascarene grass frog Ptychadena cf. mascareniensis (Amphibia: Ptychadenidae). A light and scanning electron microscopic studies.

    Science.gov (United States)

    Abdel-Gaber, Rewaida; Abdel-Ghaffar, Fathy; Kamel, Reem; Maher, Sherein; El Deeb, Nashwa; Al Quraishy, Saleh; Mehlhorn, Heinz

    2017-06-01

    The Mascarene grass frog Ptychadena cf. mascareniensis is a species of frog with a vast area of distribution in Africa. A total of 300 frog specimens were collected from different localities at El-Giza province, Egypt; then dissected and examined for the presence of parasitic infection. Only eighty six (28.66%) specimens were found to be naturally infected with nematode parasite. Seasonally, the prevalence of infection was reached its maximum value of 74.66% during summer and minimum values of 26.66% (20/75), 13.33% (10/75) during spring and autumn, respectively; while no records were observed during winter season. The morphology of the recovered parasite was studied by using light and scanning electron microscopy. The adult worm characterized by anterior extremity with small mouth opening being surrounded by three lips provided with four sub-median cephalic papillae and one pair of lateral amphids. Body measurements showed that male worms were smaller than females measuring 1.22-2.43 (2.21 ± 0.1) mm in length and 0.21-0.34 (0.29 ± 0.01) mm in width. Females measured 1.9-3.7 (2.8 ± 0.1) mm in length and 0.24-0.42 (0.38 ± 0.01) mm in width. Comparing the present parasite with other species of the same genus described previously, several similarities were observed. However, peculiar new characteristics such as the arrangement of plectanes and somatic papillae, the presence of gubernaculum, the position of nerve ring, excretory pore, and vulval opening make it reasonable belongs to the family Cosmocercidae and identified as Cosmocerca sp. In addition, the present study was the first report for occurrence of cosmocercid species from the Mascarene grass frog in Egypt.

  7. Evolutionary and natural history of the turtle frog, Myobatrachus gouldii, a bizarre myobatrachid frog in the southwestern Australian biodiversity hotspot.

    Directory of Open Access Journals (Sweden)

    Samantha Vertucci

    Full Text Available Southwest Australia (SWA is a global biodiversity hotspot and a centre of diversity and endemism for the Australo-Papuan myobatrachid frogs. Myobatrachus gouldii (the turtle frog has a highly derived morphology associated with its forward burrowing behaviour, largely subterranean habit, and unusual mode of reproduction. Its sister genera Metacrinia and Arenophryne have restricted distributions in Western Australia with significant phylogeographic structure, leading to the recent description of a new species in the latter. In contrast, Myobatrachus is distributed widely throughout SWA over multiple climatic zones, but little is known of its population structure, geographic variation in morphology, or reproduction. We generated molecular and morphological data to test for genetic and morphological variation, and to assess whether substrate specialisation in this species may have led to phylogeographic structuring similar to that of other plant and animal taxa in SWA. We assembled sequence data for one mitochondrial and four nuclear DNA loci (3628 base pairs for 42 turtle frogs sampled throughout their range. Likelihood phylogenetic analyses revealed shallow phylogeographic structure in the mtDNA locus (up to 3.3% genetic distance and little variation in three of the four nDNA loci. The mtDNA haplotype network suggests five geographically allopatric groups, with no shared haplotypes between regions. These geographic patterns are congruent with several other SWA species, with genetic groups restricted to major hydrological divisions, the Swan Coastal Plain, and the Darling Scarp. The geographically structured genetic groups showed no evidence of significant morphological differentiation (242 individuals, and there was little sexual size dimorphism, but subtle differences in reproductive traits suggest more opportunistic breeding in lower rainfall zones. Call data were compared to sister genera Metacrinia and Arenophryne and found to be highly

  8. Effects of environmental pollution on the liver parenchymal cells and Kupffer-melanomacrophagic cells of the frog Rana esculenta.

    Science.gov (United States)

    Fenoglio, Carla; Boncompagni, Eleonora; Fasola, Mauro; Gandini, Carlo; Comizzoli, Sergio; Milanesi, Gloria; Barni, Sergio

    2005-03-01

    In vertebrates, the biotransformation processes of xenobiotics are performed mainly by the liver which involves both hepatocytes and Kupffer-melanomacrophagic cells through enzymatic and nonenzymatic mechanisms. In this study, we investigated the liver of Rana esculenta adult frogs collected at two sample rice fields, one heavily polluted and one relatively unpolluted. Water pollution was determined by chemical analysis on tadpoles. The specific activities of some enzymes (glucose-6-phosphate dehydrogenase (G6PDH), acid and alkaline phosphatases (AcPase and AlkPase), succinic dehydrogenase (SDH), and catalase) were studied in the liver of adult frogs to identify the possible changes induced by contamination in the metabolic processes which depend on the function of the liver. The production of reactive oxygen species (ROS) were also evaluated through histochemical techniques. In the polluted samples, hepatocytes showed variations in the activity of G6PDH, AlkPase, and SDH and a moderate to intense ROS expression. Prominent changes were observed in Kupffer cells (KCs) and melanomacrophages (MMPs), both showing intense reactivity for AcPase and catalase and variations in melanin content and distribution. Results thus indicate a general adaptive response of liver parenchyma to environmental pollution. The possible role of both KCs and MMPs as scavengers of foreign substances is discussed.

  9. Diamond in the rough: a new species of fossorial diamond frog (Rhombophryne from Ranomafana National Park, southeastern Madagascar

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    Shea M. Lambert

    2017-02-01

    Full Text Available We describe a new species from the cophyline microhylid genus Rhombophryne, a group of fossorial and terrestrial frogs endemic to Madagascar. Found during herpetofaunal surveys of moist montane forest in the remote north of Ranomafana National Park, Rhombophryne nilevina sp. n. exemplifies two difficulties that hinder taxonomic progress in Malagasy cophyline frogs: micro-endemicity and highly secretive habits. Known from only two adult male specimens, this new species is nonetheless easily distinguishable from all other known Rhombophryne using morphological data, and osteological data collected here via X-ray Micro-Computed Tomography, or “micro-CT”. This species is now the largest known Rhombophryne, and the only one known from Ranomafana National Park, which will make it the southern-most member of the genus pending a forthcoming taxonomic revision involving Plethodontohyla and Rhombophryne. Pairwise distances of the mitochondrial 16s rRNA marker show a minimum genetic distance of 4.9% from other nominal Rhombophryne. We also describe recordings of an advertisement call, emitted from a burrow by the holotype. Rhombophryne nilevina sp. n. is not known to be found syntopically with other Rhombophryne, nor to be present elsewhere in Ranomafana National Park, but it probably does co-occur with a few ecologically similar Plethodontohyla species. Although the type locality is within a protected area, we suggest an IUCN listing of Data Deficient for R. nilevina sp. n., as its area of occupancy is largely undetermined within the park.

  10. Discovery of Larval Gnathostoma nipponicum in Frogs and Snakes from Jeju-do (Province), Republic of Korea

    Science.gov (United States)

    Woo, Ho-Choon; Oh, Hong-Shik; Cho, Shin-Hyeong; Na, Byoung-Kuk

    2011-01-01

    A survey was performed to find out the intermediate hosts of Gnathostoma nipponicum in Jeju-do (Province), the Republic of Korea. In August 2009 and 2010, a total of 82 tadpoles, 23 black-spotted pond frogs (Rana nigromaculata), 7 tiger keelback snakes (Rhabdophis tigrinus tigrinus), 6 red-tongue viper snakes (Agkistrodon ussuriensis), and 2 cat snakes (Elaphe dione) were collected in Jeju-do and examined by the pepsin-HCl digestion method. Total 5 gnathostome larvae were detected in 3 (50%) of 6 A. ussuriensis, 70 larvae in 3 of 7 (42.9%) R. tigrinus tigrinus, and 2 larvae in 2 of 82 (8.7%) frogs. No gnathostome larvae were detected in tadpoles and cat snakes. The larvae detected were a single species, and 2.17×0.22 mm in average size. They had characteristic head bulbs, muscular esophagus, and 4 cervical sacs. Three rows of hooklets were arranged in the head bulbs, and the number of hooklets in each row was 29, 33, and 36 posteriorly. All these characters were consistent with the advanced third-stage larvae of G. nipponicum. It has been first confirmed in Jeju-do that R. nigromaculata, A. ussuriensis, and R. tigrinus tigrinus play a role for intermediate and/or paratenic hosts for G. nipponicum. PMID:22355217

  11. Seasonality of Freeze Tolerance in a Subarctic Population of the Wood Frog, Rana sylvatica

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    Jon P. Costanzo

    2014-01-01

    Full Text Available We compared physiological characteristics and responses to experimental freezing and thawing in winter and spring samples of the wood frog, Rana sylvatica, indigenous to Interior Alaska, USA. Whereas winter frogs can survive freezing at temperatures at least as low as −16°C, the lower limit of tolerance for spring frogs was between −2.5°C and −5°C. Spring frogs had comparatively low levels of the urea in blood plasma, liver, heart, brain, and skeletal muscle, as well as a smaller hepatic reserve of glycogen, which is converted to glucose after freezing begins. Consequently, following freezing (−2.5°C, 48 h tissue concentrations of these cryoprotective osmolytes were 44–88% lower than those measured in winter frogs. Spring frogs formed much more ice and incurred extensive cryohemolysis and lactate accrual, indicating that they had suffered marked cell damage and hypoxic stress during freezing. Multiple, interactive stresses, in addition to diminished cryoprotectant levels, contribute to the reduced capacity for freeze tolerance in posthibernal frogs.

  12. The effects of experimentally infecting Australian tree frogs with lungworms (Rhabdias pseudosphaerocephala) from invasive cane toads.

    Science.gov (United States)

    Pizzatto, Lígia; Shine, Richard

    2011-08-01

    Invasive species may transmit novel pathogens to native taxa, and lacking a history of coevolutionary interactions with the pathogen, the new hosts may be severely affected. Cane toads (Rhinella marina) were introduced to Australia in 1935, bringing with them a lungworm (Rhabdias pseudosphaerocephala) not found in Australian frogs. Previous studies suggest that most frog species are unaffected by this parasite, but one tree-frog (Litoria caerulea) can harbour high numbers of lungworm. More detailed laboratory studies confirm and extend the earlier results on L. caerulea and show that Rhabdias infection severely depresses the viability of metamorphs of an allied tree-frog species, Litoria splendida. Parasitic larvae infected both of these two closely related tree-frog species, but the two anurans differed in the consequences of infection. Parasitism reduced the survivorship of L. splendida and the stamina of both species. Lungworms did not consistently reduce growth rates or affect heart rates in either tree-frog species. Although L. splendida is potentially vulnerable to the arrival of toad-transported lungworms, rates of host-switching may be reduced by low levels of habitat overlap between the frogs (which are rock-dwelling and arboreal) and the toads (which are terrestrial and most abundant in disturbed habitats). Copyright © 2011 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  13. Mycobacterium marinum infection in Japanese forest green tree frogs (Rhacophorus arboreus).

    Science.gov (United States)

    Haridy, M; Tachikawa, Y; Yoshida, S; Tsuyuguchi, K; Tomita, M; Maeda, S; Wada, T; Ibi, K; Sakai, H; Yanai, T

    2014-01-01

    Four Japanese forest green tree frogs (Rhacophorus arboreus) were presented with emaciation, abdominal distention and ulcerative and nodular cutaneous lesions affecting the brisket, limbs, digits and ventral abdomen. Another three frogs had been found dead in the same tank 1 year previously. Necropsy examination of these seven frogs revealed splenomegaly and hepatomegaly, with multiple tan-yellow nodular foci present in the liver, spleen, heart, lungs, ovaries and kidneys. Microscopically, five frogs had necrosis and surrounding granulomatous inflammation in the liver, spleen, kidneys, lungs, intestine and ovaries, with numerous acid-fast bacilli in the areas of necrosis. Two frogs had granulomatous lesions in the lungs, liver, spleen, heart, coelomic membrane, stomach and intestinal wall. These lesions had no or minimal necrosis and few acid-fast bacilli. Mycobacterium spp. was cultured from three frogs and identified as Mycobacterium marinum by colony growth rate and photochromogenicity and DNA sequencing. This is the first report of M. marinum infection in Japanese forest green tree frogs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Landing in basal frogs: evidence of saltational patterns in the evolution of anuran locomotion

    Science.gov (United States)

    Essner, Richard L.; Suffian, Daniel J.; Bishop, Phillip J.; Reilly, Stephen M.

    2010-10-01

    All frogs are assumed to jump in a similar manner by rapidly extending hindlimbs during the propulsive phase and rotating the limbs forward during flight in order to land forelimbs first. However, studies of jumping behavior are lacking in the most primitive living frogs of the family Leiopelmatidae. These semi-aquatic or terrestrial anurans retain a suite of plesiomorphic morphological features and are unique in using an asynchronous (trot-like) rather than synchronous “frog-kick” swimming gait of other frogs. We compared jumping behavior in leiopelmatids to more derived frogs and found that leiopelmatids maintain extended hindlimbs throughout flight and landing phases and do not land on adducted forelimbs. These “belly-flop” landings limit the ability for repeated jumps and are consistent with a riparian origin of jumping in frogs. The unique behavior of leiopelmatids shows that frogs evolved jumping before they perfected landing. Moreover, an inability to rapidly cycle the limbs may provide a functional explanation for the absence of synchronous swimming in leiopelmatids.

  15. Embryo Development of Tree Frog Polypedates leucomystax at Campus of State University of Malang

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    Pearlindah

    2012-12-01

    Full Text Available Tree frogs live in natural places which are unpolluted. Regarding their role as an ecological indicator, the decrease of frogs population in a particular habitat indicates the danger of environment quality decrease. Moreover, this condition can harm the frogs themselves. All kinds of frogs breed in aqueous environment such as ponds, marshes, and farming fields. One of the tree frogs, Polypedates leucomystax, which belongs to Familia Rachophoridae, is widely spread in Indonesia. This frog has yellowish brown skin with black spots or six lines extending from head to the posterior tip of body. A breeding couple of the frog produces foam nests on the water or plants around water body, where they will nest their fertilized eggs. This species produces over a hundred embryos in one spawning season. These embryos require appropriate conditions to develop normally in the nature. Frog embryo development may becomes a reference to understand how the frog population survives. This study focused on P. leucomystax with regards to its decrease in number due to the drying up of the environment and a lot lost of trees in Campus of State University of Malang. The development of P. leucomystax embryos in the reproduction foam was observed until it reached a tadpole stage. The result showed that the embryos developed in the foam until they hatched then they move out of the foam into the water under which they would continue their development. Considering that water body is a critical requirement for the development of P. leucomystax embryos, it is our responsibility to make any efforts to conserve not only the trees but also any type of water bodies including ponds, marshes, and farming fields as well.

  16. Living in a same microhabitat should means eating the same food? Diet and trophic niche of sympatric leaf-litter frogs Ischnocnema henselii and Adenomera marmorata in a forest of Southern Brazil

    Directory of Open Access Journals (Sweden)

    M. Santos-Pereira

    Full Text Available In this study we analyzed diet composition, niche breadth and overlap of the two leaf-litter frogs Ischnocnema henselii and Adenomera marmorata. Frogs were collected in an Atlantic Rainforest area in the Reserva Natural Salto Morato, in Paraná State, Southern Brazil, using plots of 16 m2 established on forest floor. Ischnocnema henselii consumed 18 different types of prey and the diet of this species was composed predominantly by Hymenoptera (Formicidae (15.4%, Araneae (13.83%, Orthoptera (6.15% and Opiliones (6.15%, whereas Adenomera marmorata consumed 15 different types of prey and its diet was composed mainly by Hymenoptera (Formicidae (45.7%, Acari (31.8% and Blattodea (14.8%. The niche breadth of I. henselii was BA = 0.43 and that of A. marmorata was BA = 0.19. The diet of the two sympatric species of leaf-litter frogs was basically composed by arthropods and the trophic niche overlap among them did not differ from expected at random. The differences in prey consumption should potentially facilitate the coexistence of two sympatric frogs on the forest floor. Possibly, this difference of prey consumption partly reflects differences in jaw width, species-specific body size of the two species and the period of activity of these two species.

  17. Evolution of advertisement calls in African clawed frogs.

    Science.gov (United States)

    Tobias, Martha L; Evans, Ben J; Kelley, Darcy B

    2011-01-01

    For most frogs, advertisement calls are essential for reproductive success, conveying information on species identity, male quality, sexual state and location. While the evolutionary divergence of call characters has been examined in a number of species, the relative impacts of genetic drift or natural and sexual selection remain unclear. Insights into the evolutionary trajectory of vocal signals can be gained by examining how advertisement calls vary in a phylogenetic context. Evolution by genetic drift would be supported if more closely related species express more similar songs. Conversely, a poor correlation between evolutionary history and song expression would suggest evolution shaped by natural or sexual selection. Here, we measure seven song characters in 20 described and two undescribed species of African clawed frogs (genera Xenopus and Silurana ) and four populations of X. laevis . We identify three call types - click, burst and trill - that can be distinguished by click number, call rate and intensity modulation. A fourth type is biphasic, consisting of two of the above. Call types vary in complexity from the simplest, a click, to the most complex, a biphasic call. Maximum parsimony analysis of variation in call type suggests that the ancestral type was of intermediate complexity. Each call type evolved independently more than once and call type is typically not shared by closely related species. These results indicate that call type is homoplasious and has low phylogenetic signal. We conclude that the evolution of call type is not due to genetic drift, but is under selective pressure.

  18. New genus of diminutive microhylid frogs from Papua New Guinea

    Directory of Open Access Journals (Sweden)

    Fred Kraus

    2010-06-01

    Full Text Available A new genus of diminutive (10.1-11.3 mm microhylid frogs is described from New Guinea that is unique in its combination ofonly seven presacral vertebrae, a reduced phalangeal formula that leaves the first fingers and first toes as vestigial nubs, and reduction of the prepollex and prehallux to single elements. Relationships to other genera are unknown, but overall similarity suggests some relationship to Cophixalus, although that genus also differs in some muscle characters and likely remains paraphyletic. The new genus contains two species, which are among the smallest known frogs in the world. Their miniaturization may be related to their inhabiting leaf litter, exploitation of which may for small size. The new genus is currently known only from one mountaintop in the southeasternmost portion of New Guinea and another on a nearby island. This region is part of the East Papuan Composite Terrane and, should this lineage prove endemic to that region, it may suggest that it originated prior to that geological unit’s docking with mainland New Guinea at 23–29 MY.

  19. Evolution of advertisement calls in African clawed frogs

    Science.gov (United States)

    Tobias, Martha L.; Evans, Ben J.; Kelley, Darcy B.

    2014-01-01

    Summary For most frogs, advertisement calls are essential for reproductive success, conveying information on species identity, male quality, sexual state and location. While the evolutionary divergence of call characters has been examined in a number of species, the relative impacts of genetic drift or natural and sexual selection remain unclear. Insights into the evolutionary trajectory of vocal signals can be gained by examining how advertisement calls vary in a phylogenetic context. Evolution by genetic drift would be supported if more closely related species express more similar songs. Conversely, a poor correlation between evolutionary history and song expression would suggest evolution shaped by natural or sexual selection. Here, we measure seven song characters in 20 described and two undescribed species of African clawed frogs (genera Xenopus and Silurana) and four populations of X. laevis. We identify three call types — click, burst and trill — that can be distinguished by click number, call rate and intensity modulation. A fourth type is biphasic, consisting of two of the above. Call types vary in complexity from the simplest, a click, to the most complex, a biphasic call. Maximum parsimony analysis of variation in call type suggests that the ancestral type was of intermediate complexity. Each call type evolved independently more than once and call type is typically not shared by closely related species. These results indicate that call type is homoplasious and has low phylogenetic signal. We conclude that the evolution of call type is not due to genetic drift, but is under selective pressure. PMID:24723737

  20. Ever-young sex chromosomes in European tree frogs.

    Science.gov (United States)

    Stöck, Matthias; Horn, Agnès; Grossen, Christine; Lindtke, Dorothea; Sermier, Roberto; Betto-Colliard, Caroline; Dufresnes, Christophe; Bonjour, Emmanuel; Dumas, Zoé; Luquet, Emilien; Maddalena, Tiziano; Sousa, Helena Clavero; Martinez-Solano, Iñigo; Perrin, Nicolas

    2011-05-01

    Non-recombining sex chromosomes are expected to undergo evolutionary decay, ending up genetically degenerated, as has happened in birds and mammals. Why are then sex chromosomes so often homomorphic in cold-blooded vertebrates? One possible explanation is a high rate of turnover events, replacing master sex-determining genes by new ones on other chromosomes. An alternative is that X-Y similarity is maintained by occasional recombination events, occurring in sex-reversed XY females. Based on mitochondrial and nuclear gene sequences, we estimated the divergence times between European tree frogs (Hyla arborea, H. intermedia, and H. molleri) to the upper Miocene, about 5.4-7.1 million years ago. Sibship analyses of microsatellite polymorphisms revealed that all three species have the same pair of sex chromosomes, with complete absence of X-Y recombination in males. Despite this, sequences of sex-linked loci show no divergence between the X and Y chromosomes. In the phylogeny, the X and Y alleles cluster according to species, not in groups of gametologs. We conclude that sex-chromosome homomorphy in these tree frogs does not result from a recent turnover but is maintained over evolutionary timescales by occasional X-Y recombination. Seemingly young sex chromosomes may thus carry old-established sex-determining genes, a result at odds with the view that sex chromosomes necessarily decay until they are replaced. This raises intriguing perspectives regarding the evolutionary dynamics of sexually antagonistic genes and the mechanisms that control X-Y recombination.

  1. The digital pads of rhacophorid tree-frogs.

    Science.gov (United States)

    Mizuhira, Vinci

    2004-01-01

    The digital pads of rhacophorid tree-frogs were studied by light and electron microscopy using a tannic acid-containing fixative. The digital pads are concave mucous epithelial structures surrounded by a soft raised epithelial border. The cells in the first epithelial layer are separated by deep intercellular fissures and the epithelial cell surface is densely covered with thousands of setaceous keratinized microvilli. These are estimated to be 0.1-0.5 microm in width and have flattened tips. A longitudinal section view of the pad's first epithelial cell layer shows a rugose pattern. Deep intercellular fissures in between the cells are formed by the enzymatic activity of invading mononuclear leukocytes in the interepithelial cell junctions. The 'rugose' surface epithelial cell layer is peeled off from the underlying second epithelial layer by the epithelial metabolism that occurs when the leukocytes invade the second interepithelial cell spaces. Thus, the second epithelial cell layer becomes the new 'rugose' epithelial cell layer. The ultrastructures of the frog digital pads are compared with those of other biological suction cups, such as those of octopuses and geckos. Further discussed are their interatomic or intermolecular mechanofunctional aspects, such as hanging upside down and moving easily over smooth surfaces with the aid of interatomic or intermolecular forces, the so-called 'van der Waals forces', without any energy expenditure.

  2. Identical skin toxins by convergent molecular adaptation in frogs.

    Science.gov (United States)

    Roelants, Kim; Fry, Bryan G; Norman, Janette A; Clynen, Elke; Schoofs, Liliane; Bossuyt, Franky

    2010-01-26

    The Tree of Life is rife with adaptive convergences at all scales and biological levels of complexity. However, natural selection is not likely to result in the independent evolution of identical gene products. Here we report such a striking example of evolutionary convergence in the toxic skin secretions of two distantly related frog lineages. Caeruleins are important decapeptides in pharmacological and clinical research [1] and are commonly believed to represent a single evolutionary class of peptides [2-4]. Instead, our phylogenetic analyses combining transcriptome and genome data reveal that independently evolved precursor genes encode identical caeruleins in Xenopus and Litoria frogs. The former arose by duplication from the cholecystokinin (cck) gene, whereas the latter was derived from the gastrin gene. These hormone genes that are involved in many physiological processes diverged early in vertebrate evolution, after a segmental duplication during the Cambrian period. Besides implicating convergent mutations of the peptide-encoding sequence, recurrent caerulein origins entail parallel shifts of expression from the gut-brain axis to skin secretory glands. These results highlight extreme structural convergence in anciently diverged genes as an evolutionary mechanism through which recurrent adaptation is attained across large phylogenetic distances. Copyright 2010 Elsevier Ltd. All rights reserved.

  3. The genetic structure of a relict population of wood frogs

    Science.gov (United States)

    Scherer, Rick; Muths, Erin; Noon, Barry; Oyler-McCance, Sara

    2012-01-01

    Habitat fragmentation and the associated reduction in connectivity between habitat patches are commonly cited causes of genetic differentiation and reduced genetic variation in animal populations. We used eight microsatellite markers to investigate genetic structure and levels of genetic diversity in a relict population of wood frogs (Lithobates sylvatica) in Rocky Mountain National Park, Colorado, where recent disturbances have altered hydrologic processes and fragmented amphibian habitat. We also estimated migration rates among subpopulations, tested for a pattern of isolation-by-distance, and looked for evidence of a recent population bottleneck. The results from the clustering algorithm in Program STRUCTURE indicated the population is partitioned into two genetic clusters (subpopulations), and this result was further supported by factorial component analysis. In addition, an estimate of FST (FST = 0.0675, P value \\0.0001) supported the genetic differentiation of the two clusters. Estimates of migration rates among the two subpopulations were low, as were estimates of genetic variability. Conservation of the population of wood frogs may be improved by increasing the spatial distribution of the population and improving gene flow between the subpopulations. Construction or restoration of wetlands in the landscape between the clusters has the potential to address each of these objectives.

  4. Negative chronotropic effect of proton pump inhibitors on frog-heart preparation.

    Science.gov (United States)

    Gautam, Chander Shekhar; Utreja, Amita; Goel, Divya; Sandhu, Gurpreet; Gogia, Nidhi

    2009-01-01

    Proton pump inhibitors (PPIs) have been known to cause bradycardia. We evaluated the effect of three PPIs, i.e. omeprazole, rabeprazole and pantoprazole on the heart rate of frog. The in situ frog heart preparation was set up. Heart rate and amplitude of contraction were studied following administration of different doses of the three PPIs. Statistical analysis was done by using Graphpad statistical software system. After 1 mg of omeprazole and rabeprazole, and 2 mg pantoprazole, the heart rate was similar as compared to baseline (p >0.05). After 2 mg of omeprazole and rabeprazole, and 4 mg pantoprazole, the reduction in heart rate was significant (p frog heart prepration.

  5. Superficial and deep blood vessel distribution in the frog telencephalon. Reference to morphological brain asymmetries.

    Science.gov (United States)

    Kemali, M; Sada, E; Fiorino, L

    1990-01-01

    Nine frogs of the species "Rana esculenta" were heart perfused with Microfile Silicone Rubber. The frogs were examined both after dissection (cut with a razor blade) to study the superficial blood vessel pattern, and histologically (the Nissl staining method) to study the distribution of the deep blood capillaries. While the superficial blood vary in pattern, the deep capillaries are distributed symmetrically. This finding does not support a correlation between blood vessel pattern and morphological brain asymmetry, at least in the frog, and thus other explanations must be sought to explain brain asymmetry.

  6. Clutch effects explain heart rate variation in embryonic frogs (Cave Coqui, Eleutherodactylus cooki).

    Science.gov (United States)

    Burggren, W; Crossley, D; Rogowitz, G; Thompson, D

    2003-01-01

    Few physiological studies to date have focused on whether variation among sibling groups during development can account for often large, intraspecific physiological variation. In this study, we measured heart rate in the direct-developing frog Eleutherodactylus cooki throughout its embryonic development and examined heart rate variation among egg clutches comprising from 10 to 40 eggs. Clutches were collected in the wild in Yubucoa, Puerto Rico, and individual eggs were maintained under equivalent conditions in the lab. Heart rate showed large increases during development, rising from about 40 beats min(-1) in the earliest stages to about 110 beats min(-1) at hatching. The effect of stage (averaged across clutches) was highly significant (P<0.001). However, repeated-measures MANOVA also revealed that there were highly significant effects on heart rate associated with both clutch (variation among clutches averaged across development; P<0.001) and clutch-stage interactions (differences among clutches in the developmental change in heart rate; P<0.0001). These effects and interactions reveal that throughout development, heart rate in siblings is much more similar than in nonsiblings and that sib groups follow different heart rate trajectories during their development. Collectively, these data indicate that "clutch effects" caused by genetic and/or maternal influences can strongly affect patterns of heart function during development within cave coqui populations. This phenomenon also occurs in bird eggs and armadillo neonates, suggesting that physiological variation attributable to clutch effects might be a widespread phenomenon in vertebrates.

  7. Seasonal infection rates of Batrachochytrium dendrobatidis in populations of northern green frog Lithobates clamitans melanota tadpoles.

    Science.gov (United States)

    Julian, James T; Gould, Victoria A; Glenney, Gavin W; Brooks, Robert P

    2016-09-26

    Few studies have documented seasonal variation of Batrachochytrium dendrobatidis (Bd) infection rates in larval amphibians. We identified 4 natural populations of northern green frogs Lithobates clamitans melanota in Pennsylvania (USA) that contained Bd-infected tadpoles during post-wintering collections in May and June, after hibernating tadpoles had overwintered in wetlands. However, we failed to detect infected tadpoles at those wetlands when pre-wintering collections were made in late July through early September. We observed 2 cohorts of tadpoles that appeared to lack Bd-infected individuals in pre-wintering collections, yet contained Bd-infected individuals the following spring. We also observed 4 cohorts of pre-wintering tadpoles that were Bd-free, even though post-wintering tadpoles collected earlier in the year were infected with Bd. Our results suggest that tadpoles either reduce Bd infections during the summer months, and/or infections proliferate sometime prior to (or shortly after) tadpoles emerge from hibernation. It is unlikely that pre-wintering tadpoles were too small to detect Bd zoospores because (1) there was no correlation between Bd zoospore levels and tadpole size or stage, and (2) size was not a significant predictor of infection status. These results suggest that, while sampling larvae can be an effective means of collecting large sample sizes, investigators in our Mid-Atlantic region should conduct sampling by early summer to maximize the chances of detecting Bd. Further research is warranted to determine whether wetland topography and warm, shallow microhabitats within wetlands contribute to a population's ability to drastically reduce Bd prevalence prior to overwintering at ponds.

  8. Oregon Spotted Frog (Rana pretiosa) Monitoring in the Oregon Cascades 2012-2016

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset contains information from visual encounter surveys conducted between 2012 and 2016 by USGS as part of an ongoing Oregon spotted frog (Rana pretiosa)...

  9. Exploratory evaluation of nutrient enrichment and frog response at Conboy Lake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — We sampled nutrient and water quality parameters and surveyed Oregon spotted frogs (Rana pretiosa) life stages (eggs, larvae and recently metamorphosed juveniles) to...

  10. Effects of ACTH4–10 on synaptic transmission in frog sympathetic ganglion

    NARCIS (Netherlands)

    Wouters, W.; Bercken, J. van den

    1979-01-01

    The influenced of ACHT4−10, a behaviourally active fragment of adrenocorticotropic hormone (ACTH) devoid of endocrine activity, on synaptic transmission in the paravertebral sympathetic ganglion of the frog was investigated. Postsynaptic potentials evoked by electrical stimulation of preganglionic

  11. Effects of oxymorphazone in frogs: long lasting antinociception in vivo, and apparently irreversible binding in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Benyhe, S.; Hoffman, G.; Varga, E.; Hosztafi, S.; Toth, G.; Borsodi, A.; Wollemann, M.

    1989-01-01

    Oxymorphazone was found to be a relatively weak antinociceptive drug in intact frog (Rana esculenta) when acetic acid was used as pain stimulus. Frogs remained analgesic for at least 48 hrs following oxymorphazone administration. The ligand increased the latency of wiping reflex in spinal frogs too. There effects were blocked by naloxone. In equilibrium binding studies (/sup 3/H)oxymorphazone had high affinity to the opioid receptors of frog brain and spinal cord as well. Kinetic experiments show that only 25% of the bound (/sup 3/H)oxymorphazone is readily dissociable. Preincubation of the membranes with labeled oxymorphazone results in a washing resistant inhibition of the opioid binding sites. At least 70% of the (/sup 3/H)oxymorphazone specific binding is apparently irreversible after reaction at 5 nM ligand concentration, and this can be enhanced by a higher concentration of tritiated ligand.

  12. Recovery plan for the California Red-legged frog (Rana aurora draytonii)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The objective of this plan is to reduce threats and improve the population status of the California red-legged frog sufficiently to warrant delisting. Actions...

  13. Gramicidin-perforated patch revealed depolarizing effect of GABA in cultured frog melanotrophs

    National Research Council Canada - National Science Library

    Frank Le Foll; Hélène Castel; Olivier Soriani; Hubert Vaudry; Lionel Cazin

    1998-01-01

    ...ˆ’ ] i ) in cultured frog melanotrophs. In the gramicidin-perforated patch configuration, 1 μM GABA caused a depolarization associated with an action potential discharge and a slight fall of membrane resistance...

  14. Report on Oregon Spotted Frog Egg Mass Surveys 2013-2015

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Oregon spotted frogs (Rana pretiosa) were once common across wetlands throughout western Washington and Oregon and were found in northern California and southern...

  15. Hargreaves does not evaluate nociception following a surgical laparotomy in Xenopus leavis frogs.

    Science.gov (United States)

    Vachon, P

    2014-10-01

    The present study was performed to determine the effectiveness of the Hargreaves test for the evaluation of nociception in frogs, more precisely to determine if cutaneous thresholds to a radiant heat stimulus would increase with analgesics following an abdominal laparotomy performed under general anaesthesia. Non breeding female Xenopus leavis frogs (3 groups (non-anaesthetized, anaesthetized with tricaine methanesulfonate (MS222), with or without an abdominal laparotomy) were used to evaluate the effectiveness of the Hargreaves test. Cutaneous thresholds were evaluated at baseline and following anaesthetic recovery (over 8 h) at six different body locations. Increased reaction times were observed in the gular area only at 1 h post-recovery following a MS222 bath immersion in frogs with (p nociception induced by an abdominal laparotomy and consequently cannot be used to evaluate analgesics in X. leavis frogs. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  16. Oregon Spotted Frog (Rana pretiosa) Monitoring in the Oregon Cascades 2012-2015

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset contains information from visual encounter surveys conducted between 2012 and 2015 by USGS as part of an ongoing Oregon spotted frog (Rana pretiosa)...

  17. Oregon Spotted Frog (Rana pretiosa) Monitoring at Jack Creek 2015-2016

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset contains information from mark-recapture and egg mass surveys conducted 2015-2016 by USGS as part of an ongoing Oregon spotted frog (Rana pretiosa)...

  18. Oregon Spotted Frog Monitoring in the Oregon Cascades 2012-2016

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset contains information from visual encounter surveys conducted between 2012 and 2016 by USGS as part of an ongoing Oregon spotted frog (Rana pretiosa)...

  19. Balancing a cline by influx of migrants: a genetic transition in water frogs of eastern Greece

    National Research Council Canada - National Science Library

    Hotz, Hansjürg; Beerli, Peter; Uzzell, Thomas; Guex, Gaston-Denis; Pruvost, Nicolas B M; Schreiber, Robert; Plötner, Jörg

    2013-01-01

    Variation patterns of allozymes and of ND3 haplotypes of mitochondrial DNA reveal a zone of genetic transition among western Palearctic water frogs extending across northeastern Greece and European Turkey...

  20. Okefenokee and Banks Lake National Wildlife Refuge 2009 Frog Abnormality Survey Summary

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Summary of frog observations for abnormal conditions at select sites on both Okefenokee and Banks Lake NWRs. During the 2009 summer, STEP students Zach Carter along...

  1. Interacting amino acid replacements allow poison frogs to evolve epibatidine resistance.

    Science.gov (United States)

    Tarvin, Rebecca D; Borghese, Cecilia M; Sachs, Wiebke; Santos, Juan C; Lu, Ying; O'Connell, Lauren A; Cannatella, David C; Harris, R Adron; Zakon, Harold H

    2017-09-22

    Animals that wield toxins face self-intoxication. Poison frogs have a diverse arsenal of defensive alkaloids that target the nervous system. Among them is epibatidine, a nicotinic acetylcholine receptor (nAChR) agonist that is lethal at microgram doses. Epibatidine shares a highly conserved binding site with acetylcholine, making it difficult to evolve resistance yet maintain nAChR function. Electrophysiological assays of human and frog nAChR revealed that one amino acid replacement, which evolved three times in poison frogs, decreased epibatidine sensitivity but at a cost of acetylcholine sensitivity. However, receptor functionality was rescued by additional amino acid replacements that differed among poison frog lineages. Our results demonstrate how resistance to agonist toxins can evolve and that such genetic changes propel organisms toward an adaptive peak of chemical defense. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  2. Stormwater wetlands can function as ecological traps for urban frogs.

    Science.gov (United States)

    Sievers, Michael; Parris, Kirsten M; Swearer, Stephen E; Hale, Robin

    2018-03-01

    Around cities, natural wetlands are rapidly being destroyed and replaced with wetlands constructed to treat stormwater. Although the intended purpose of these wetlands is to manage urban stormwater, they are inhabited by wildlife that might be exposed to contaminants. These effects will be exacerbated if animals are unable to differentiate between stormwater treatment wetlands of varying quality and some function as 'ecological traps' (i.e. habitats that animals prefer despite fitness being lower than in other habitats). To examine if urban stormwater wetlands can be ecological traps for frogs, we tested if survival, metamorphosis-related measures and predator avoidance behaviours of frogs differed within mesocosms that simulated stormwater wetlands with different contaminant levels, and paired this with a natural oviposition experiment to assess breeding-site preferences. We provide the first empirical evidence that these wetlands can function as ecological traps for frogs. Tadpoles had lower survival and were less responsive to predator olfactory cues when raised in more polluted stormwater wetlands, but also reached metamorphosis earlier and at a larger size. A greater size at metamorphosis was likely a result of increased per capita food availability due to higher mortality combined with eutrophication, although other compensatory effects such as selective-mortality removing smaller individuals from low-quality mesocosms may also explain these results. Breeding adults laid comparable numbers of eggs across wetlands with high and low contaminant levels, indicating no avoidance of the former. Since stormwater treatment wetlands are often the only available aquatic habitat in urban landscapes we need to better understand how they perform as habitats to guide management decisions that mitigate their potential ecological costs. This may include improving wetland quality so that fitness is no longer compromised, preventing colonisation by animals, altering the cues

  3. Karakteristik Parsial Gen Sitokrom-C Oksidase Subunit-I Katak Pohon Suaka Marga Satwa Tanjung Peropa Moramo, Sulawesi Tenggara (CHARACTERISTICS OF PARTIAL CYTOCHROME C OXIDASE SUBUNIT I (COI GENE OF TREE FROG (Polypedates celebensis IN TANJUNG PEROPA WI

    Directory of Open Access Journals (Sweden)

    Suriana Suriana

    2017-01-01

    Full Text Available Tree frog (Polypedates celebensis is an endemic amphibi found in Southeast Sulawesi. Database ofthis species, in particular genetic databases is still very limited. The purpose of this research was tocharacterize the partial gene cytochrome C oxidase subunit I (COI of tree frog (P. celebensis. Frog sampleswere collected from Tanjung Peropa Wildlife Reserve, Moramo, Southeast Sulawesi, and extracted theirDNA genome, and amplified using the polymerase chain reaction (PCR method, with specific primers,and then sequenced. Characterization was done by comparing the COI gene with another COI gene fromother frog (data available on GenBank. The results showed that the COI gene fragment P. celebensisconsisted of 665 base pairs. These fragment gene had 99% conserved nucleotides, and only 1% nucleotidesthat varied. Nine sites of nucleotide varied namely: 65th, 98th, 101th, 358th, 396th, 403th, 405th, 424th, and426th. These sites of nucleotide varied can be used as genetic markers for P. celebensis. Composition ofnitrogenous bases P. celebensis COI gene fragment were 29.9% timine, 28.9% cytocine, 22.0% adenine, and19.2% guanine. Molecular phylogeny of P. celebensis based on 665 bp of their COI gene suggests that thesespecies was monophyletic. It is concluded that the gene fragment of cytochrome C oxidase of tree frog (P.celebensis the origin of Wildlife Moramo, Southeast Sulawesi, has conserved nucleotides more thannucleotides that varied. These varied nucleotides can be used as genetic markers especially for the treefrog origin of Wildlife Moramo, Southeast Sulawesi. The most nitrogenous bases is thymine, while thefewest is guanine. Molecular phylogeny based on cytochrome C oxidase gene is monophyletic

  4. Glycogen synthase kinase-3: cryoprotection and glycogen metabolism in the freeze-tolerant wood frog.

    Science.gov (United States)

    Dieni, Christopher A; Bouffard, Melanie C; Storey, Kenneth B

    2012-02-01

    The terrestrial anuran Rana sylvatica tolerates extended periods of whole-body freezing during the winter. Freezing survival is facilitated by extensive glycogen hydrolysis and distribution of high concentrations of the cryoprotectant glucose into blood and all tissues. As glycogenesis is both an energy-expensive process and counter-productive to maintaining sustained high cryoprotectant levels, we proposed that glycogen synthase kinase-3 (GSK-3) would be activated when wood frogs froze and would phosphorylate its downstream substrates to inactivate glycogen synthesis. Western blot analysis determined that the amount of phosphorylated (inactive) GSK-3 decreased in all five tissues tested in 24 h frozen frogs compared with unfrozen controls. Total GSK-3 protein levels did not change, with the exception of heart GSK-3, indicating that post-translational modification was the primary regulatory mechanism for this kinase. Kinetic properties of skeletal muscle GSK-3 from control and frozen frogs displayed differential responses to a temperature change (22 versus 4°C) and high glucose. For example, when assayed at 4°C, the K(m) for the GSK-3 substrate peptide was ∼44% lower for frozen frogs than the corresponding value in control frogs, indicating greater GSK-3 affinity for its substrates in the frozen state. This indicates that at temperatures similar to the environment encountered by frogs, GSK-3 in frozen frogs will phosphorylate its downstream targets more readily than in unfrozen controls. GSK-3 from skeletal muscle of control frogs was also allosterically regulated. AMP and phosphoenolpyruvate activated GSK-3 whereas inhibitors included glucose, glucose 6-phosphate, pyruvate, ATP, glutamate, glutamine, glycerol, NH(4)Cl, NaCl and KCl. The combination of phosphorylation and allosteric control argues for a regulatory role of GSK-3 in inactivating glycogenesis to preserve high glucose cryoprotectant levels throughout each freezing bout.

  5. Reproduction and hybrid load in all-hybrid populations of Rana esculenta water frogs in Denmark

    DEFF Research Database (Denmark)

    Christiansen, Ditte Guldager; Fog, Kåre; Pedersen, Bo Vest

    2005-01-01

    All-hybrid populations of the water frog, Rana esculenta, are exceptional in consisting of independently and to some extent sexually reproducing interspecific hybrids. In most of its range R. esculenta reproduces hemiclonally with one of the parental species, R. lessonae or R. ridibunda, but viable...... gametogenesis and mating between frogs with incompatible gametes induce a significant hybrid load in all-hybrid populations of R. esculenta, and we discuss compensating advantages and potential evolutionary trajectories to reduce this hybrid load....

  6. Interference of a short-chain phospholipid with ion transport pathways in frog skin

    DEFF Research Database (Denmark)

    Unmack, M A; Frederiksen, O; Willumsen, N J

    1997-01-01

    The effects of mucosal application of the short-chain phospholipid didecanoyl-L-alpha-phosphatidylcholine (DDPC; with two saturated 10-carbon acyl chains) on active Na+ transport and transepithelial conductance (G) in the frog skin (Rana temporaria) were investigated. Active Na+ transport...... of the frog skin epithelium and opens a paracellular tight junction pathway. Both effects may be caused by incorporation of DDPC in the apical cell membrane....

  7. Nuclear Abnormalities in Erythrocytes of Frogs From Wetlands and Croplands of Western Ghats Indicate Environmental Contaminations

    OpenAIRE

    Raghunath, Shreyas; Veerabhadrappa, Chethankumar Masaruru; Krishnamurthy, Sannanegunda Venkatarama Bhatta

    2017-01-01

    Anuran amphibians are the biological models to assess the influence of environmental contamination. We conducted nuclear abnormality assessment and micronuclei test in erythrocytes of frogs to identify an early influence of environmental contaminations. In Western Ghats of India, farmers use different agrochemicals and obviously, the amphibian habitat is contaminated with combinations of many residues. Many frog species use these agro-ecosystem for breeding and to complete early life stage. I...

  8. Pecular Features of Hematopoiesis in the Liver of Mature and Immature Green Frogs (Pelophylax Esculentus Complex

    Directory of Open Access Journals (Sweden)

    Akulenko N. M.

    2016-12-01

    Full Text Available The article describes characteristic features of the hematopoiesis in mature and immature green frogs (Pelophylax esculentus complex. Quantitative differences in liver myelograms were insignificant. However, in a sample of mature animals numerous significant correlations between the number of pigment inclusions in the liver and indicators of erythropoiesis and myelopoiesis were observed. Those correlations were absent in the immature frogs. We concluded that aft er the frogs’ breeding a lack of plastic resources, in particular, hemosiderin remains up to the hibernation.

  9. Impact of Dams on Riparian Frog Communities in the Southern Western Ghats, India

    Directory of Open Access Journals (Sweden)

    Rohit Naniwadekar

    2014-08-01

    Full Text Available The Western Ghats is a global biodiversity hotspot and home to diverse and unique assemblages of amphibians. Several rivers originate from these mountains and hydropower is being tapped from them. The impacts of hydrological regulation of riparian ecosystems to wildlife and its habitat are poorly documented, and in particular the fate of frog populations is unknown. We examined the effects of dams on riparian frog communities in the Thamirabarani catchment in southern Western Ghats. We used nocturnal visual encounter surveys constrained for time, to document the species richness of frogs below and above the dam, and also at control sites in the same catchment. While we did not find differences in species richness below and above the dams, the frog community composition was significantly altered as a likely consequence of altered flow regime. The frog species compositions in control sites were similar to above-dam sites. Below-dam sites had a distinctly different species composition. Select endemic frog species appeared to be adversely impacted due to the dams. Below-dam sites had a greater proportion of generalist and widely distributed species. Dams in the Western Ghats appeared to adversely impact population of endemic species, particularly those belonging to the genus Nyctibatrachus that shows specialization for intact streams.

  10. The scotopic and photopic visual sensitivity in the nocturnal tree frog Agalychnis callidryas.

    Science.gov (United States)

    Liebau, Arne; Eisenberg, Tobias; Esser, Karl-Heinz

    2015-10-01

    The red-eyed tree frog (Agalychnis callidryas) is endemic to the rainforests of Central America. During the night, it hunts for insects in the treetops whereas at daytime, the frogs rest under leaves. In the present study we determined the relative visual sensitivity spectrum of this nocturnal frog species by ERG recordings in both the dark- and light-adapted state. In both the scotopic- and photopic-sensitivity curve, we found only minor individual variations among the tested individuals. The sensitivity maximum of the scotopic curve was determined at 500 nm, which matches the absorption properties of the RH1-visual pigment expressed in the red rods of frogs. The sensitivity maximum of the photopic curve was found at 545 nm which is close to the absorption maximum of the LWS pigment type expressed in most cones of the frog retina. The threshold curves determined by ERG recordings here reveal no unusual features in the sensitivity spectrum of the red-eyed tree frog that could be interpreted as adaptations for its strictly nocturnal life style.

  11. Reciprocal subsidies in ponds: does leaf input increase frog biomass export?

    Science.gov (United States)

    Earl, Julia E; Semlitsch, Raymond D

    2012-12-01

    Reciprocal subsidies occur when ecosystems are paired, both importing and exporting resources to each other. The input of subsidies increases reciprocal subsidy export, but it is unclear how this changes with other important factors, such as ambient resources. We provide a conceptual framework for reciprocal subsidies and empirical data testing this framework using a pond-forest system in Missouri, USA. Our experiment used in situ pond mesocosms and three species of anurans: wood frogs, American toads, and southern leopard frogs. We predicted that increases in ambient resources (primary productivity) and detrital subsidy input (deciduous tree leaves) into pond mesocosms would increase reciprocal export (frog biomass) to the surrounding terrestrial ecosystem. In contrast, we found that increases in primary productivity consistently decreased frog biomass, except with leaf litter inputs. With leaf inputs, primary productivity did not affect the export of frogs, indicating that leaf detritus and associated microbial communities may be more important than algae for frog production. We found that subsidy inputs tended to increase reciprocal exports, and thus partial concordance with our conceptual framework.

  12. The island rule in the Brazilian frog Phyllodytes luteolus (Anura: Hylidae: incipient gigantism?

    Directory of Open Access Journals (Sweden)

    Marcio Mageski

    2015-10-01

    Full Text Available ABSTRACT The island rule suggests that, when mainland animals are isolated on islands, large animals tend to become smaller, while small animals tend to become larger. A small frog in eastern Brazil, Phyllodytes luteolus (Wied-Neuwied, 1824, is widely distributed in association with bromeliads. At the end of the last glaciation, parts of the mainland became islands due to rising sea levels, thereby isolating frog populations on these islands. If the island rule holds, we predicted that frogs on islands would tend to be larger than frogs on the mainland. We compared sizes (weight and length of 30 randomly selected male frogs from the mainland with 30 from an island in the state of Espírito Santo, Brazil. We also sampled population density on the island and mainland because concurrent with changing sizes, depending on the causal relationship, density may also change. As predicted, island frogs tended to be larger (both in snout-vent length and weight and were much more abundant. While not specifically addressed in this study, the absence of predators and interspecific competitors may explain both of these trends.

  13. Placement of intracoelomic radio transmitters and silicone passive sampling devices in northern leopard frogs (Lithobates pipiens)

    Science.gov (United States)

    Zaffarano, Bianca Anne; Yaw, Taylor; Swanson, Jennifer E; Pierce, Clay; Muths, Erin L.; Smalling, Kelly; Vandever, Mark

    2017-01-01

    Historically, wetland toxin exposure studies have relied on single time point samples from stationary sampling devices. Development of passive sampling devices (PSDs) that can be attached to individual animals within wetland habitats has greatly improved in recent years, presenting an innovative sampling technology that can potentially yield individual-specific, quantifiable data about chemical exposure. In this study, silicone based PSDs were attached to the ventral skin of 20 northern leopard frogs (Lithobates pipiens) with polypropylene sutures after radio transmitters had been surgically implanted into the coleomic cavity. After a recovery period frogs were released back into the wetland habitat where they were acquired. The animals were located daily using radio telemetry to assess how long PSDs would remain attached in the frogs' natural habitat. After one week, PSDs remained on 18 of the original 20 frogs. At 2 weeks 17 frogs were recovered and no PSDs remained attached. Although valuable data can be obtained over a short time period, more research will be necessary to demonstrate effectiveness of externally attaching silicone PSDs to northern leopard frogs for time periods longer than 1-2 weeks.

  14. Origin of invasive Florida frogs traced to Cuba

    Science.gov (United States)

    Heinicke, Matthew P.; Diaz, Luis M.; Hedges, S. Blair

    2011-01-01

    Two of the earliest examples of successful invasive amphibians are the greenhouse frog (Eleutherodactylus planirostris) and the Cuban treefrog (Osteopilus septentrionalis) in Florida. Although both are generally assumed to be recent introductions, they are widespread on Caribbean islands and also have been proposed as natural colonizers. We obtained nucleotide sequence data for both species and their closest relatives in their native and introduced ranges. Phylogenetic analyses trace the origin of E. planirostris to a small area in western Cuba, while O. septentrionalis is derived from at least two Cuban sources, one probably a remote peninsula in western Cuba. The tropical-to-temperate invasion began with colonization of the Florida Keys followed by human-mediated dispersal within peninsular Florida. The subtropical Keys may have served as an adaptive stepping stone for the successful invasion of the North American continent. PMID:21270024

  15. Biophysics of directional hearing in the frog Eleutherodactylus coqui

    DEFF Research Database (Denmark)

    Jørgensen, Morten Buhl; Schmitz, Barbara; Christensen-Dalsgaard, Jakob

    1991-01-01

    1. We used laser vibrometry and free field sound stimulation to study the frequency responses of the eardrum and the lateral body wall of awake male Eleutherodactylus coqui. 2. The eardrum snowed one of two distinct frequency responses depending on whether the glottis was open (GO response......) or closed (GC response) during the measurement. 3. The lateral body wall vibrated with a maximum amplitude close to that of the eardrum and in the same frequency range. 4. Covering the frog's body wall with vaseline reduced the vibration amplitude of the GC response by up to 15 dB. 5. When a closed sound...... delivery system was used to stimulate a local area of the body wall the eardrum also showed one of two types of responses. 6. These results suggest that sound is transmitted via the lung cavity to the internal surface of the eardrum. This lung input has a significant influence on the vibrations...

  16. Ciliary function of the frog oro-pharyngeal epithelium.

    Science.gov (United States)

    Aiello, E; Sleigh, M

    1977-03-09

    The palate epithelium of the frog was examined by scanning electron microscopy, light microscopy and high speed cine micrography. The cilia remain stationary for much of time in the end-of-effective stroke position. Each beat cycle begins with a forwardly-directed recovery stroke lasting about 60 ms, followed by an effective stroke towards the oesophagus lasting about 12 ms. Activity can often be correlated with the presence of mucus, which is carried as strands on the tips of the ciliary effective strokes whilst the recovery strokes move beneath the mucus. Coordination of ciliary activity was very variable; local antiplectic metachrony of the recovery strokes could almost always be seen, and on very active epithelia effective strokes were associated with approximately diaplectic waves (either to left or right), but any particular pattern of coordinated activity was transient and quickly transformed to another pattern. Beating and coordination of these short cilia were compared with those of cilia propelling water.

  17. Photoinduced toxicity of fluoranthene to northern leopard frogs (Rana pipiens)

    Energy Technology Data Exchange (ETDEWEB)

    Monson, P.D.; Call, D.J.; Cox, D.A.; Liber, K. [Univ. of Wisconsin, Superior, WI (United States). Lake Superior Research Inst.; Ankley, G.T. [Environmental Protection Agency, Duluth, MN (United States). Mid-Continent Ecology Div.

    1999-02-01

    Rana pipiens larvae were exposed for 48 h in a flow-through system to clean water or five concentrations of the phototoxic polycyclic aromatic hydrocarbon (PAH) fluoranthene. Following this uptake period, the larvae were divided into four groups: one for immediate tissue residue analysis, a second for residue analysis following 48 h of depuration in clean water, and two for a 48-h exposure in clean water to ultraviolet (UV) light at two different levels. At the highest treatment, mean intensity was 8.12 {+-} 0.19 {times} 10{sup 2} {micro}W/cm{sup 2}, whereas at a lower treatment the UVA intensity was 4.45 {+-} 0.05 {times} 10{sup 2} {micro}W/cm{sup 2}. Larval frogs bioaccumulated fluoranthene in direct proportion to the water exposure concentrations, with initial whole-body PAH concentrations of 1.48, 3.53, 4.85, 11.3, and 18.7 {micro}g/g at the five treatment levels. No mortality of the animals occurred during the 48-h uptake phase. When the frogs were placed in clean water, the fluoranthene was rapidly depurated, with up to 80% lost in 48 h. Exposure to UV light following fluoranthene exposure significantly enhanced toxicity of the PAH. Median time to death decreased as the product of UVA light intensity and fluoranthene body residue increased. For larval R. Pipiens, sufficient tissue residues of fluoranthene were bioaccumulated within 48 h, at water exposure concentrations in the range of 2 to 10 {micro}g/L, to be lethal when combined with a UVA exposure simulating a fraction of summertime, midday sunlight in northern latitudes.

  18. Ever-young sex chromosomes in European tree frogs.

    Directory of Open Access Journals (Sweden)

    Matthias Stöck

    2011-05-01

    Full Text Available Non-recombining sex chromosomes are expected to undergo evolutionary decay, ending up genetically degenerated, as has happened in birds and mammals. Why are then sex chromosomes so often homomorphic in cold-blooded vertebrates? One possible explanation is a high rate of turnover events, replacing master sex-determining genes by new ones on other chromosomes. An alternative is that X-Y similarity is maintained by occasional recombination events, occurring in sex-reversed XY females. Based on mitochondrial and nuclear gene sequences, we estimated the divergence times between European tree frogs (Hyla arborea, H. intermedia, and H. molleri to the upper Miocene, about 5.4-7.1 million years ago. Sibship analyses of microsatellite polymorphisms revealed that all three species have the same pair of sex chromosomes, with complete absence of X-Y recombination in males. Despite this, sequences of sex-linked loci show no divergence between the X and Y chromosomes. In the phylogeny, the X and Y alleles cluster according to species, not in groups of gametologs. We conclude that sex-chromosome homomorphy in these tree frogs does not result from a recent turnover but is maintained over evolutionary timescales by occasional X-Y recombination. Seemingly young sex chromosomes may thus carry old-established sex-determining genes, a result at odds with the view that sex chromosomes necessarily decay until they are replaced. This raises intriguing perspectives regarding the evolutionary dynamics of sexually antagonistic genes and the mechanisms that control X-Y recombination.

  19. Apical Na+ permeability of frog skin during serosal Cl- replacement.

    Science.gov (United States)

    Leibowich, S; DeLong, J; Civan, M M

    1988-05-01

    Gluconate substitution for serosal Cl- reduces the transepithelial short-circuit current (Isc) and depolarizes short-circuited frog skins. These effects could result either from inhibition of basolateral K+ conductance, or from two actions to inhibit both apical Na+ permeability (PapNa) and basolateral pump activity. We have addressed this question by studying whole-and split-thickness frog skins. Intracellular Na+ concentration (CcNa) and PapNa have been monitored by measuring the current-voltage relationship for apical Na+ entry. This analysis was conducted by applying trains of voltage pulses, with pulse durations of 16 to 32 msec. Estimates of PapNa and CcNa were not detectably dependent on pulse duration over the range 16 to 80 msec. Serosal Cl- replacement uniformly depolarized short-circuited tissues. The depolarization was associated with inhibition of Isc across each split skin, but only occasionally across the whole-thickness preparations. This difference may reflect the better ionic exchange between the bulk medium and the extracellular fluid in contact with the basolateral membranes, following removal of the underlying dermis in the split-skin preparations. PapNa was either unchanged or increased, and CcNa either unchanged or reduced after the anionic replacement. These data are incompatible with the concept that serosal Cl- replacement inhibits PapNa and Na,K-pump activity. Gluconate substitution likely reduces cell volume, triggering inhibition of the basolateral K+ channels, consistent with the data and conclusions of S.A. Lewis, A.G. Butt, M.J. Bowler, J.P. Leader and A.D.C. Macknight (J. Membrane Biol. 83:119-137, 1985) for toad bladder. The resulting depolarization reduces the electrical force favoring apical Na+ entry. The volume-conductance coupling serves to conserve volume by reducing K+ solute loss. Its molecular basis remains to be identified.

  20. Muscle fatigue in frog semitendinosus: alterations in contractile function

    Science.gov (United States)

    Thompson, L. V.; Balog, E. M.; Riley, D. A.; Fitts, R. H.

    1992-01-01

    The purpose of this study was to characterize the contractile properties of the frog semitendinosus (ST) muscle before and during recovery from fatigue, to relate the observed functional changes to alterations in specific steps in the crossbridge model of muscle contraction, and to determine how fatigue affects the force-frequency relationship. The frog ST (22 degrees C) was fatigued by direct electrical stimulation with 100-ms 150-Hz trains at 1/s for 5 min. The fatigue protocol reduced peak twitch (Pt) and tetanic (Po) force to 32 and 8.5% of initial force, respectively. The decline in Pt was less than Po, in part due to a prolongation in the isometric contraction time (CT), which increased to 300% of the initial value. The isometric twitch duration was greatly prolonged as reflected by the lengthened CT and the 800% increase in the one-half relaxation time (1/2RT). Both Pt and Po showed a biphasic recovery, a rapid initial phase (2 min) followed by a slower (40 min) return to the prefatigue force. CT and 1/2RT also recovered in two phases, returning to 160 and 265% of control in the first 5 min. CT returned to the prefatigue value between 35 and 40 min, whereas even at 60 min 1/2RT was 133% of control. The maximal velocity of shortening, determined by the slack test, was significantly reduced [from 6.7 +/- 0.5 to 2.5 +/- 0.4 optimal muscle length/s] at fatigue. The force-frequency relationship was shifted to the left, so that optimal frequency for generating Po was reduced.(ABSTRACT TRUNCATED AT 250 WORDS).

  1. Phylogeography of four frog species in forest fragments of northeastern Brazil--a preliminary study.

    Science.gov (United States)

    Carnaval, Ana Carolina O Q

    2002-11-01

    I contrast mitochondrial DNA genealogies based on 612 bp of the cytochrome b gene across four co-distributed species of frogs in Northeastern Brazil. They are Hyla albomarginata, Hyla branneri, Proceratophrys boiei, and Scinax nebulosus. Samples were collected from the core or edge of six rainforest remnants in the states of Pernambuco and Alagoas. Three fragments are located within the humid Atlantic Forest morphoclimatic domain (municipalities of Cabo de Santo Agostinho, Ibateguara, and Jaqueira), two are located in the transition zone between the Atlantic Forest domain and the semi-arid Caatinga (Caruaru and Timbaúba), and one is found within the Caatinga (Brejo da Madre de Deus). Results show that local patterns and levels of genetic diversity are influenced by taxon-specific habitat requirements. Populations of the montane, closed-canopy species P. boiei show strong geographical structure, reflecting barriers to gene flow that predate human-driven habitat destruction. Species occurring along forest edges, such as H. albomarginata and S. nebulosus, show genetic patterns similar to those of P. boiei, but lower levels of genetic divergence. The more generalist Hyla branneri shows no geographic pattern. The data are in agreement with distribution and fossil data gathered for other groups of organisms, suggesting that mesic forests occupied the currently arid Caatinga in the recent past.

  2. The prospective science teachers’ perspectives of dissection experiments: Calf’s heart, fish and frog dissection

    Directory of Open Access Journals (Sweden)

    Beşoluk Şenol

    2016-01-01

    Full Text Available This study aims to find out the sophomore prospective science teachers’ cognitive emotional reactions, physiological-motor reactions with regard to a calf’s heart, fish and frog dissection in biology laboratory experiments. Meanwhile to find out if they had a choice, they would prefer to do or not to do these dissections. In this study a phenomenological design was used which is involving a qualitative research method. The sample consisted of totally 43 (37 female and 6 male sophomore prospective science teachers in 2013-2014 spring term. The data was collected with using of a questionnaire which was developed by one of the researcher. The data was analyzed through qualitative descriptive analysis. According to the results of the study, the prospective science teachers’ cognitive emotional reactions were mainly categorized as positive and negative feelings. Positive feelings were curiosity, interest, excitement, enjoyable and pleasure and also negative feelings were disgust, displeasure, sad, stress and fear. Also five physiological-motor reactions were found. These were queasiness, trembling hands, loss of appetite, dizziness and dry mouth.

  3. A new species of tree frog genus Rhacophorus from Sumatra, Indonesia Amphibia, Anura).

    Science.gov (United States)

    Hamidy, Amir; Kurniati, Hellen

    2015-04-14

    A small-sized tree frog of the genus Rhacophorus is described on the basis of 18 specimens collected from three different localities on Sumatra Island, Indonesia. Rhacophorus indonesiensis sp. nov. is divergent from all other Rhacophorus species genetically and morphologically. The new species is distinguished from its congeners by a combination of: the presence of black spots on the ventral surfaces of the hand and foot webbing, an absence of vomerine teeth, a venter with a white kite-shaped marking, raised white spots on the dorsum or on the head, and a reddish brown dorsum with irregular dark brown blotches and distinct black dots. With the addition of this new species, fifteen species of Rhacophorus are now known from Sumatra, the highest number of species of this genus in the Sundaland region. However, with the increasing conversion of forest to oil palm cultivation or mining, the possibility of the extinction of newly described or as yet undiscovered species is of great concern.

  4. MHC genotypes associate with resistance to a frog-killing fungus.

    Science.gov (United States)

    Savage, Anna E; Zamudio, Kelly R

    2011-10-04

    The emerging amphibian disease chytridiomycosis is caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd). Amphibian populations and species differ in susceptibility to Bd, yet we know surprisingly little about the genetic basis of this natural variation. MHC loci encode peptides that initiate acquired immunity in vertebrates, making them likely candidates for determining disease susceptibility. However, MHC genes have never been characterized in the context of chytridiomycosis. Here, we performed experimental Bd infections in laboratory-reared frogs collected from five populations that show natural variation in Bd susceptibility. We found that alleles of an expressed MHC class IIB locus associate with survival following Bd infection. Across populations, MHC heterozygosity was a significant predictor of survival. Within populations, MHC heterozygotes and individuals bearing MHC allele Q had a significantly reduced risk of death, and we detected a significant signal of positive selection along the evolutionary lineage leading to allele Q. Our findings demonstrate that immunogenetic variation affects chytridiomycosis survival under controlled experimental conditions, confirming that host genetic polymorphisms contribute to chytridiomycosis resistance.

  5. The Molecular Biology of Frog Virus 3 and other Iridoviruses Infecting Cold-Blooded Vertebrates

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    Kwang H. Yu

    2011-10-01

    Full Text Available Frog virus 3 (FV3 is the best characterized member of the family Iridoviridae. FV3 study has provided insights into the replication of other family members, and has served as a model of viral transcription, genome replication, and virus-mediated host-shutoff. Although the broad outlines of FV3 replication have been elucidated, the precise roles of most viral proteins remain unknown. Current studies using knock down (KD mediated by antisense morpholino oligonucleotides (asMO and small, interfering RNAs (siRNA, knock out (KO following replacement of the targeted gene with a selectable marker by homologous recombination, ectopic viral gene expression, and recombinant viral proteins have enabled researchers to systematically ascertain replicative- and virulence-related gene functions. In addition, the application of molecular tools to ecological studies is providing novel ways for field biologists to identify potential pathogens, quantify infections, and trace the evolution of ecologically important viral species. In this review, we summarize current studies using not only FV3, but also other iridoviruses infecting ectotherms. As described below, general principles ascertained using FV3 served as a model for the family, and studies utilizing other ranaviruses and megalocytiviruses have confirmed and extended our understanding of iridovirus replication. Collectively, these and future efforts will elucidate molecular events in viral replication, intrinsic and extrinsic factors that contribute to disease outbreaks, and the role of the host immune system in protection from disease.

  6. Indirana chiravasi, a new species of Leaping Frog (Anura: Ranixalidae from Western Ghats of India

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    A.D. Padhye

    2014-09-01

    Full Text Available Indirana chiravasi, a new species of leaping frog is described from the northern Western Ghats around Amboli, Sindhudurg District, Maharashtra, India. It differs from all its congeners based on a combination of characters including presence of median single internal vocal sac, head longer than wide, distinct canthus rostralis, tympanum 2/3rd to 3/4th the diameter of eye, vomerine teeth in two oblique series at the posterior border of choanae, long midventral lingual papilla, first finger longer than or equal to second, presence of double outer palmer tubercle, thin and elongated inner metatarsal tubercle, absence of outer metatarsal tubercle, webbing moderate, dorsal skin with glandular folds but without warts, ventral skin smooth without mottling and palms and soles dark brown. Molecular analysis based on mitochondrial 12S and 16S genes and nuclear rhodopsin and rag1 genes suggests that the species is genetically distinct from other species for which genetic data is available. Preliminary observations on the development of the species are also provided. We also provide genetic data and images for Indirana gundia collected from the type locality.

  7. Predictive-like distribution mapping using Google Earth: reassessment of the distribution of the bromeligenous frog, Scinax v-signatus (Anura: Hylidae).

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    Da Silva, Helio Ricardo; Alves-Silva, Ricardo

    2013-01-29

    The hylid frog Scinax perpusillus species group comprises 13 species that share, in addition to a few morphological features, reproduction that occurs exclusively associated with bromeliads. Among the species in the group, Scinax v-signatus (Lutz, 1968) is one of the few with a relatively large geographic distribution, occurring in association with bromeliads growing on granitic outcrops above 800 m along the Serra dos Órgãos (a local designation of Serra do Mar) in the Atlantic forest, State of Rio de Janeiro. Here we demonstrate that previous assessment of the distribution of this species was overestimated, and reevaluate the available data on its occurrence. The distributional data analyzed was based on three levels of evidence. First, we assessed the distribution of the bromeliad, Alcantarea imperialis (Carrière) Harms, which is used by S. v-signatus at the type locality. We plotted potential occurrence data for this plant using Google Earth (GE) by visually inspecting GE images in search of indications of granitic outcrops where groups and large individual bromeliads could be identified. Second, we plotted the distribution of these plants and that of the frog based on locality data taken from the literature and voucher specimens in natural history collections and checked for congruence between these sets of data. Third, as a second test of accuracy of this methodology we visited four new localities indicated by the bromeliad-occurrence GE prediction map and searched for the occurrence of both the frog and the bromeliad. This simple process has proven efficient and accurate in finding new collecting sites and determining the distribution of the two involved taxa. We discuss this and other possibilities of using Google Earth as a tool for mapping and discovering the distribution of organisms and habitats. Furthermore, this study has shed light on a more accurate and realistic estimate of the distribution of Scinax v-signatus with implications for the

  8. Defects in host immune function in tree frogs with chronic chytridiomycosis.

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    Young, Sam; Whitehorn, Paul; Berger, Lee; Skerratt, Lee F; Speare, Rick; Garland, Stephen; Webb, Rebecca

    2014-01-01

    The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) has caused mass mortality leading to population declines and extinctions in many frog species worldwide. The lack of host resistance may be due to fungal immunosuppressive effects that have been observed when Bd is incubated with cultured lymphocytes, but whether in vivo host immunosuppression occurs is unknown. We used a broad range of hematologic and protein electrophoresis biomarkers, along with various functional tests, to assess immune competence in common green (Litoria caerulea) and white-lipped (L. infrafrenata) tree frogs experimentally infected with Bd. Compared with uninfected frogs, Bd infection in L. caerulea caused a reduction in immunoglobulin and splenic lymphocyte responses to antigenic stimulation with sheep red blood cells, along with decreased white blood cell and serum protein concentrations, indicating possible impaired immune response capability of Bd-infected frogs. This is the first in vivo study suggesting that infection with Bd causes multiple defects in systemic host immune function, and this may contribute to disease development in susceptible host species. Although L. infrafrenata failed to maintain Bd infection after exposure, white blood cell and serum globulin concentrations were lower in recovered frogs compared with unexposed frogs, but antigen-specific serum and splenic antibody, and splenic cellular, responses were similar in both recovered and unexposed frogs. This may indicate potential systemic costs associated with infection clearance and/or redirection of host resources towards more effective mechanisms to overcome infection. No clear mechanism for resistance was identified in L. infrafrenata, suggesting that localized and/or innate immune defense mechanisms may be important factors involved in disease resistance in this species.

  9. Defects in host immune function in tree frogs with chronic chytridiomycosis.

    Directory of Open Access Journals (Sweden)

    Sam Young

    Full Text Available The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd has caused mass mortality leading to population declines and extinctions in many frog species worldwide. The lack of host resistance may be due to fungal immunosuppressive effects that have been observed when Bd is incubated with cultured lymphocytes, but whether in vivo host immunosuppression occurs is unknown. We used a broad range of hematologic and protein electrophoresis biomarkers, along with various functional tests, to assess immune competence in common green (Litoria caerulea and white-lipped (L. infrafrenata tree frogs experimentally infected with Bd. Compared with uninfected frogs, Bd infection in L. caerulea caused a reduction in immunoglobulin and splenic lymphocyte responses to antigenic stimulation with sheep red blood cells, along with decreased white blood cell and serum protein concentrations, indicating possible impaired immune response capability of Bd-infected frogs. This is the first in vivo study suggesting that infection with Bd causes multiple defects in systemic host immune function, and this may contribute to disease development in susceptible host species. Although L. infrafrenata failed to maintain Bd infection after exposure, white blood cell and serum globulin concentrations were lower in recovered frogs compared with unexposed frogs, but antigen-specific serum and splenic antibody, and splenic cellular, responses were similar in both recovered and unexposed frogs. This may indicate potential systemic costs associated with infection clearance and/or redirection of host resources towards more effective mechanisms to overcome infection. No clear mechanism for resistance was identified in L. infrafrenata, suggesting that localized and/or innate immune defense mechanisms may be important factors involved in disease resistance in this species.

  10. An Analysis of Predator Selection to Affect Aposematic Coloration in a Poison Frog Species.

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    Corinna E Dreher

    Full Text Available Natural selection is widely noted to drive divergence of phenotypic traits. Predation pressure can facilitate morphological divergence, for example the evolution of both cryptic and conspicuous coloration in animals. In this context Dendrobatid frogs have been used to study evolutionary forces inducing diversity in protective coloration. The polytypic strawberry poison frog (Oophaga pumilio shows strong divergence in aposematic coloration among populations. To investigate whether predation pressure is important for color divergence among populations of O. pumilio we selected four mainland populations and two island populations from Costa Rica and Panama. Spectrometric measurements of body coloration were used to calculate color and brightness contrasts of frogs as an indicator of conspicuousness for the visual systems of several potential predators (avian, crab and snake and a conspecific observer. Additionally, we conducted experiments using clay model frogs of different coloration to investigate whether the local coloration of frogs is better protected than non-local color morphs, and if predator communities vary among populations. Overall predation risk differed strongly among populations and interestingly was higher on the two island populations. Imprints on clay models indicated that birds are the main predators while attacks of other predators were rare. Furthermore, clay models of local coloration were equally likely to be attacked as those of non-local coloration. Overall conspicuousness (and brightness contrast of local frogs was positively correlated with attack rates by birds across populations. Together with results from earlier studies we conclude that conspicuousness honestly indicates toxicity to avian predators. The different coloration patterns among populations of strawberry poison frogs in combination with behavior and toxicity might integrate into equally efficient anti-predator strategies depending on local predation and

  11. The biomechanics of tree frogs climbing curved surfaces: a gripping problem.

    Science.gov (United States)

    Hill, Iain D C; Dong, Benzheng; Barnes, W Jon P; Ji, Aihong; Endlein, Thomas

    2018-01-19

    The adhesive mechanisms of climbing animals have become an important research topic because of their biomimetic implications. We examined the climbing abilities of hylid tree frogs on vertical cylinders of differing diameter and surface roughness to investigate the relative roles of adduction forces (gripping) and adhesion. Tree frogs adhere using their toe pads and subarticular tubercles, the adhesive joint being fluid-filled. Our hypothesis was that, on an effectively flat surface (adduction forces on the largest 120 mm diameter cylinder were insufficient to allow climbing), adhesion would effectively be the only means by which tree frogs could climb, but on the two smaller diameter cylinders (44 mm and 13 mm), frogs could additionally utilise adduction forces by gripping the cylinder either with their limbs outstretched or by grasping around the cylinder with their digits, respectively. The frogs' performance would also depend on whether the surfaces were smooth (easy to adhere to) or rough (relatively non-adhesive). Our findings showed that climbing performance was highest on the narrowest smooth cylinder. Frogs climbed faster, frequently using a 'walking trot' gait rather than the 'lateral sequence walk' used on other cylinders. Using an optical technique to visualize substrate contact during climbing on smooth surfaces, we also observed an increasing engagement of the subarticular tubercles on the narrower cylinders. Finally, on the rough substrate, frogs were unable to climb the largest diameter cylinder, but were able to climb the narrowest one slowly. These results support our hypotheses and have relevance for the design of climbing robots. © 2018. Published by The Company of Biologists Ltd.

  12. Cytological maps of lampbrush chromosomes of European water frogs (Pelophylax esculentus complex) from the Eastern Ukraine

    Science.gov (United States)

    2013-01-01

    Background Hybridogenesis (hemiclonal inheritance) is a kind of clonal reproduction in which hybrids between parental species are reproduced by crossing with one of the parental species. European water frogs (Pelophylax esculentus complex) represent an appropriate model for studying interspecies hybridization, processes of hemiclonal inheritance and polyploidization. P. esculentus complex consists of two parental species, P. ridibundus (the lake frog) and P. lessonae (the pool frog), and their hybridogenetic hybrid – P. esculentus (the edible frog). Parental and hybrid frogs can reproduce syntopically and form hemiclonal population systems. For studying mechanisms underlying the maintenance of water frog population systems it is required to characterize the karyotypes transmitted in gametes of parental and different hybrid animals of both sexes. Results In order to obtain an instrument for characterization of oocyte karyotypes in hybrid female frogs, we constructed cytological maps of lampbrush chromosomes from oocytes of both parental species originating in Eastern Ukraine. We further identified certain molecular components of chromosomal marker structures and mapped coilin-rich spheres and granules, chromosome associated nucleoli and special loops accumulating splicing factors. We recorded the dissimilarities between P. ridibundus and P. lessonae lampbrush chromosomes in the length of orthologous chromosomes, number and location of marker structures and interstitial (TTAGGG)n-repeat sites as well as activity of nucleolus organizer. Satellite repeat RrS1 was mapped in centromere regions of lampbrush chromosomes of the both species. Additionally, we discovered transcripts of RrS1 repeat in oocytes of P. ridibundus and P. lessonae. Moreover, G-rich transcripts of telomere repeat were revealed in association with terminal regions of P. ridibundus and P. lessonae lampbrush chromosomes. Conclusions The constructed cytological maps of lampbrush chromosomes of P

  13. An Analysis of Predator Selection to Affect Aposematic Coloration in a Poison Frog Species.

    Science.gov (United States)

    Dreher, Corinna E; Cummings, Molly E; Pröhl, Heike

    2015-01-01

    Natural selection is widely noted to drive divergence of phenotypic traits. Predation pressure can facilitate morphological divergence, for example the evolution of both cryptic and conspicuous coloration in animals. In this context Dendrobatid frogs have been used to study evolutionary forces inducing diversity in protective coloration. The polytypic strawberry poison frog (Oophaga pumilio) shows strong divergence in aposematic coloration among populations. To investigate whether predation pressure is important for color divergence among populations of O. pumilio we selected four mainland populations and two island populations from Costa Rica and Panama. Spectrometric measurements of body coloration were used to calculate color and brightness contrasts of frogs as an indicator of conspicuousness for the visual systems of several potential predators (avian, crab and snake) and a conspecific observer. Additionally, we conducted experiments using clay model frogs of different coloration to investigate whether the local coloration of frogs is better protected than non-local color morphs, and if predator communities vary among populations. Overall predation risk differed strongly among populations and interestingly was higher on the two island populations. Imprints on clay models indicated that birds are the main predators while attacks of other predators were rare. Furthermore, clay models of local coloration were equally likely to be attacked as those of non-local coloration. Overall conspicuousness (and brightness contrast) of local frogs was positively correlated with attack rates by birds across populations. Together with results from earlier studies we conclude that conspicuousness honestly indicates toxicity to avian predators. The different coloration patterns among populations of strawberry poison frogs in combination with behavior and toxicity might integrate into equally efficient anti-predator strategies depending on local predation and other ecological

  14. Ultraviolet radiation influences perch selection by a neotropical poison-dart frog.

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    Lee B Kats

    Full Text Available Ambient ultraviolet-B radiation can harm amphibian eggs, larvae and adults. However, some amphibians avoid UV-B radiation when given the opportunity. The strawberry poison dart frog, Oophaga pumilio, is diurnal and males vocalize throughout the day in light gaps under forest canopies that expose them to solar radiation. Previous studies have demonstrated that males calling from high perches are more successful at mating than those at lower perches. We investigated whether frogs at higher perches receive more ultraviolet-B than those calling from lower perches. We also investigated whether frogs on perches receiving relatively low ultraviolet-B levels maintained their positions for longer compared to individuals calling from perches receiving higher levels of ultraviolet-B. Finally, since it has been hypothesized that some animals utilize levels of UV-A as a visual cue to avoid UV-B damage, we artificially elevated ultraviolet-A levels to examine whether males exposed to artificially elevated ultraviolet-A abandoned their perches sooner compared to males exposed to visible light. We found that frogs called from perches receiving low ultraviolet-B regardless of perch height, and that frogs maintain their positions longer on perches receiving low ultraviolet-B compared to perches receiving even slightly higher ultraviolet-B levels. Exposing the frogs to artificially elevated levels of ultraviolet-A radiation caused males to move off of their perches faster than when they were exposed to a control light source. These experiments suggest that ultraviolet radiation plays an important role in frog behavior related to perch selection, even in rainforests where much of the solar radiation is shielded by the forest canopy.

  15. Enzymatic regulation of glycogenolysis in a subarctic population of the wood frog: implications for extreme freeze tolerance.

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    M Clara F do Amaral

    Full Text Available The wood frog, Rana sylvatica, from Interior Alaska survives freezing at -16°C, a temperature 10-13°C below that tolerated by its southern conspecifics. We investigated the hepatic freezing response in this northern phenotype to determine if its profound freeze tolerance is associated with an enhanced glucosic cryoprotectant system. Alaskan frogs had a larger liver glycogen reserve that was mobilized faster during early freezing as compared to conspecifics from a cool-temperate region (southern Ohio, USA. In Alaskan frogs the rapid glucose production in the first hours of freezing was associated with a 7-fold increase in glycogen phosphorylase activity above unfrozen frog levels, and the activity of this enzyme was higher than that of frozen Ohioan frogs. Freezing of Ohioan frogs induced a more modest (4-fold increase in glycogen phosphorylase activity above unfrozen frog values. Relative to the Ohioan frogs, Alaskan frogs maintained a higher total protein kinase A activity throughout an experimental freezing/thawing time course, and this may have potentiated glycogenolysis during early freezing. We found populational variation in the activity and protein level of protein kinase A which suggested that the Alaskan population had a more efficient form of this enzyme. Alaskan frogs modulated their glycogenolytic response by decreasing the activity of glycogen phosphorylase after cryoprotectant mobilization was well under way, thereby conserving their hepatic glycogen reserve. Ohioan frogs, however, sustained high glycogen phosphorylase activity until early thawing and consumed nearly all their liver glycogen. These unique hepatic responses of Alaskan R. sylvatica likely contribute to this phenotype's exceptional freeze tolerance, which is necessary for their survival in a subarctic climate.

  16. Enzymatic regulation of glycogenolysis in a subarctic population of the wood frog: implications for extreme freeze tolerance.

    Science.gov (United States)

    do Amaral, M Clara F; Lee, Richard E; Costanzo, Jon P

    2013-01-01

    The wood frog, Rana sylvatica, from Interior Alaska survives freezing at -16°C, a temperature 10-13°C below that tolerated by its southern conspecifics. We investigated the hepatic freezing response in this northern phenotype to determine if its profound freeze tolerance is associated with an enhanced glucosic cryoprotectant system. Alaskan frogs had a larger liver glycogen reserve that was mobilized faster during early freezing as compared to conspecifics from a cool-temperate region (southern Ohio, USA). In Alaskan frogs the rapid glucose production in the first hours of freezing was associated with a 7-fold increase in glycogen phosphorylase activity above unfrozen frog levels, and the activity of this enzyme was higher than that of frozen Ohioan frogs. Freezing of Ohioan frogs induced a more modest (4-fold) increase in glycogen phosphorylase activity above unfrozen frog values. Relative to the Ohioan frogs, Alaskan frogs maintained a higher total protein kinase A activity throughout an experimental freezing/thawing time course, and this may have potentiated glycogenolysis during early freezing. We found populational variation in the activity and protein level of protein kinase A which suggested that the Alaskan population had a more efficient form of this enzyme. Alaskan frogs modulated their glycogenolytic response by decreasing the activity of glycogen phosphorylase after cryoprotectant mobilization was well under way, thereby conserving their hepatic glycogen reserve. Ohioan frogs, however, sustained high glycogen phosphorylase activity until early thawing and consumed nearly all their liver glycogen. These unique hepatic responses of Alaskan R. sylvatica likely contribute to this phenotype's exceptional freeze tolerance, which is necessary for their survival in a subarctic climate.

  17. Rangewide phylogeography of the western U.S. endemic frog Rana boylii (Ranidae): Implications for the conservation of frogs and rivers

    Science.gov (United States)

    A.J. Lind; H.B. Shaffer; P.Q. Spinks; G.M. Fellers

    2011-01-01

    Genetic data are increasingly being used in conservation planning for declining species. We sampled both the ecological and distributional limits of the foothill yellow-legged frog, Rana boylii to characterize mitochondrial DNA (mtDNA) variation in this declining, riverine amphibian. We evaluated 1525 base pairs (bp) of cytochrome b...

  18. Prevalence of Spirometra mansoni in dogs, cats, and frogs and its medical relevance in Guangzhou, China.

    Science.gov (United States)

    Hong, Qing; Feng, Jieping; Liu, Haijuan; Li, Xiaomin; Gong, Lirong; Yang, Zhen; Yang, Weiming; Liang, Xiongfa; Zheng, Rujiang; Cui, Zhicai; Wang, Weiliang; Chen, Daixiong

    2016-12-01

    Sparganosis is an important parasitic disease in Guangzhou and is mainly acquired through the consumption of frog meat or contact with fresh frogs infected by larval stages (spargana) of the tapeworm species Spirometra mansoni. In this study, the prevalence of intestinal S. mansoni infections (with adult parasites) in dogs and cats and of extraintestinal S. mansoni infections (with spargana) in frogs was assessed. In addition, a questionnaire survey was carried out among residents in Guangzhou City in order to evaluate their awareness about the medical and epidemiological relevance of Spirometra and sparganosis. In total, the feces of 229 dogs and 116 cats were examined for eggs, and 1949 frogs were examined for spargana. Sixty-three dogs (27.5%) and 47 cats (40.5%) had eggs in their feces. Two hundred and sixteen out of 416 wild Rana tigrina rugulosa Wiegmann frogs examined were sparganum-positive, with an infection rate of 51.9%, while the infection rate in Rana limnocharis Boie was 35.1% (13/37). None of the tested farmed frogs (including R. tigrina rugulosa and Rana catesbeiana) was positive (0/1382). Analysis of the questionnaire revealed the following results: (1) about 41.0% of residents in Guangzhou had some knowledge of sparganosis or sparganum infection, and information in TV programs was the most important way that residents learned about sparganosis. (2) About 59.9% of the residents ate frog meat. Eating the meat, viscera, or blood of animals, e.g., frogs, snakes, pigs, chicken, mice, and birds, in an improper way might be the main means by which residents acquire the infection. (3) The risk of sparganum infection was higher in males than in females. A high sparganum infection rate was observed in the wild frogs sold in agricultural product markets in Guangzhou. The infection was also serious in cats and dogs in Guangdong Province. With lifestyles and eating habits resulting in sparganum infection, it is necessary to focus on market management and

  19. Composition and Functional Specialists of the Gut Microbiota of Frogs Reflect Habitat Differences and Agricultural Activity.

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    Huang, Bing-Hong; Chang, Chun-Wen; Huang, Chih-Wei; Gao, Jian; Liao, Pei-Chun

    2017-01-01

    The physiological impact of agricultural pollution, habitat disturbance, and food source variability on amphibian remains poorly understood. By comparing the composition and predicted functions of gut microbiota of two frog species from forest and farmland, we quantified the effects of the exogenous environment and endogenous filters on gut microbiota and the corresponding functions. However, compositional differences of the gut microbiota between the frog species were not detected, even when removing roughly 80-88% of the confounding effect produced by common and shared bacteria (i.e., generalists) and those taxa deemed too rare. The habitat effect accounted for 14.1% of the compositional difference of gut microbial specialists, but host and host × habitat effects were not significant. Similar trends of a significant habitat effect, at an even higher level (26.0%), for the physiological and metabolic functions of gut microbiota was predicted. A very obvious skewing of the relative abundance of functional groups toward farmland habitats reflects the highly diverse bacterial functions of farmland frogs, in particular related to pathogenic disease and pesticide degradation, which may be indication of poor adaptation or strong selective pressure against disease. These patterns reflect the impacts of agricultural activities on frogs and how such stresses may be applied in an unequal manner for different frog species.

  20. Comparison of metal bioavailability in frogs from urban and rural sites of Western Ukraine.

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    Stolyar, O B; Loumbourdis, N S; Falfushinska, H I; Romanchuk, L D

    2008-01-01

    The seasonal and spatial fluctuations of heavy metals in the liver of the frog Rana ridibunda from a river in Western Ukraine were investigated. Liver weight was seen to increase from spring to summer/autumn, most probably as a result of accumulation of metabolites, especially fat and glycogen. The concentrations of the metals found in the liver of the frog was in the order: Fe>Cu approximately Zn>Mn>Cd. For most metals, the highest concentration was recorded in the frogs inhabiting the urban site. The highest level of Cu in the liver was observed in the spring, in the agricultural site, while the highest level of other metals was observed in the summer. The most probable explanation for the high concentration of Cu in the rural site was that in this wetland there were discharge effluents from fungicides with Cu in their formula. Compared to other metals, the bioavailability of Cu was approximately 1000 times higher. The high concentration of Fe rather reflects its fluctuation in the water. Despite its very low concentration in the water (below the limit of detection), Cd was detected in the liver of frogs inhabiting both sites. This is an indication that tissues accumulate Cd, despite the very low concentration detected in the water. This may be an indication of intermittent exposure of frogs to Cd and possibly of other heavy metals.

  1. Urea loading enhances freezing survival and postfreeze recovery in a terrestrially hibernating frog.

    Science.gov (United States)

    Costanzo, Jon P; Lee, Richard E

    2008-09-01

    We tested the hypothesis that urea, an osmolyte accumulated early in hibernation, functions as a cryoprotectant in the freeze-tolerant wood frog, Rana sylvatica. Relative to saline-treated, normouremic (10 micromol ml(-1)) frogs, individuals rendered hyperuremic (70 micromol ml(-1)) by administration of an aqueous urea solution exhibited significantly higher survival (100% versus 64%) following freezing at -4 degrees C, a potentially lethal temperature. Hyperuremic frogs also had lower plasma levels of intracellular proteins (lactate dehydrogenase, creatine kinase, hemoglobin), which presumably escaped from damaged cells, and more quickly recovered neurobehavioral functions following thawing. Experimental freezing-thawing did not alter tissue urea concentrations, but did elevate glucose levels in the blood and organs of all frogs. When measured 24 h after thawing commenced, glucose concentrations were markedly higher in urea-loaded frogs as compared to saline-treated ones, possibly because elevated urea retarded glucose clearance. Like other low-molecular-mass cryoprotectants, urea colligatively reduces both the amount of ice forming within the body and the osmotic dehydration of cells. In addition, by virtue of certain non-colligative properties, it may bestow additional protection from freeze-thaw damage not afforded by glucose.

  2. Chemical camouflage--a frog's strategy to co-exist with aggressive ants.

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    Mark-Oliver Rödel

    Full Text Available Whereas interspecific associations receive considerable attention in evolutionary, behavioural and ecological literature, the proximate bases for these associations are usually unknown. This in particular applies to associations between vertebrates with invertebrates. The West-African savanna frog Phrynomantis microps lives in the underground nest of ponerine ants (Paltothyreus tarsatus. The ants usually react highly aggressively when disturbed by fiercely stinging, but the frog is not attacked and lives unharmed among the ants. Herein we examined the proximate mechanisms for this unusual association. Experiments with termites and mealworms covered with the skin secretion of the frog revealed that specific chemical compounds seem to prevent the ants from stinging. By HPLC-fractionation of an aqueous solution of the frogs' skin secretion, two peptides of 1,029 and 1,143 Da were isolated and found to inhibit the aggressive behaviour of the ants. By de novo sequencing using tandem mass spectrometry, the amino acid sequence of both peptides consisting of a chain of 9 and 11 residues, respectively, was elucidated. Both peptides were synthesized and tested, and exhibited the same inhibitory properties as the original frog secretions. These novel peptides most likely act as an appeasement allomone and may serve as models for taming insect aggression.

  3. Transmission of Batrachochytrium dendrobatidis to wood frogs (Lithobates sylvaticus) via a bullfrog (L. catesbeianus) vector.

    Science.gov (United States)

    Greenspan, Sasha E; Calhoun, Aram J K; Longcore, Joyce E; Levy, Michael G

    2012-07-01

    Chytridiomycosis, an emerging infectious disease caused by the chytrid fungus Batrachochytrium dendrobatidis, threatens anuran populations worldwide. Effects of B. dendrobatidis on frog species are variable. Some species typically develop nonlethal infections and may function as carriers; others typically develop lethal infections that can lead to population declines. Nonlethal infections in the bullfrog (Lithobates catesbeianus) are well-documented. In contrast, recently metamorphosed wood frogs (L. sylvaticus) can die from chytridiomycosis. We conducted an ex-situ experiment between May and July 2010 to determine whether B. dendrobatidis-infected bullfrogs could transmit the fungus to wood frog tadpoles when the two species shared a body of water. We tested for B. dendrobatidis infections with quantitative polymerase chain reactions (qPCR) in a subsample of the wood frog tadpoles and in all metamorphosed wood frogs and compared risk of death of froglets exposed and unexposed to infected bullfrogs. We detected B. dendrobatidis sporadically in subsampled treatment tadpoles (nine of 90, 10%) and frequently in treatment froglets (112 of 113, 99.1%). Pooled risk of froglet death was higher (Pdendrobatidis in this species. We highlight bullfrog disease screening as a management challenge, especially in light of exotic bullfrog colonies on multiple continents and large-scale global trade in this species. We document the importance of quantifying lethal and sublethal effects of bullfrog vectors on B. dendrobatidis-susceptible species.

  4. Citizen Science Program Shows Urban Areas Have Lower Occurrence of Frog Species, but Not Accelerated Declines.

    Directory of Open Access Journals (Sweden)

    Martin J Westgate

    Full Text Available Understanding the influence of landscape change on animal populations is critical to inform biodiversity conservation efforts. A particularly important goal is to understand how urban density affects the persistence of animal populations through time, and how these impacts can be mediated by habitat provision; but data on this question are limited for some taxa. Here, we use data from a citizen science monitoring program to investigate the effect of urbanization on patterns of frog species richness and occurrence over 13 years. Sites surrounded by a high proportion of bare ground (a proxy for urbanization had consistently lower frog occurrence, but we found no evidence that declines were restricted to urban areas. Instead, several frog species showed declines in rural wetlands with low-quality habitat. Our analysis shows that urban wetlands had low but stable species richness; but also that population trajectories are strongly influenced by vegetation provision in both the riparian zone and the wider landscape. Future increases in the extent of urban environments in our study area are likely to negatively impact populations of several frog species. However, existing urban areas are unlikely to lose further frog species in the medium term. We recommend that landscape planning and management focus on the conservation and restoration of rural wetlands to arrest current declines, and the revegetation of urban wetlands to facilitate the re-expansion of urban-sensitive species.

  5. Osmotic and metabolic responses to dehydration and urea-loading in a dormant, terrestrially hibernating frog.

    Science.gov (United States)

    Muir, Timothy J; Costanzo, Jon P; Lee, Richard E

    2007-11-01

    Physiological responses to dehydration in amphibians are reasonably well documented, although little work has addressed this problem in hibernating animals. We investigated osmotic and metabolic responses to experimental manipulation of hydration state in the wood frog (Rana sylvatica), a terrestrial hibernator that encounters low environmental water potential during autumn and winter. In winter-conditioned frogs, plasma osmolality varied inversely with body water content (range 69-79%, fresh mass) primarily due to increases in sodium and chloride concentrations, as well as accumulation of glucose and urea. Decreased hydration was accompanied by a marked reduction in the resting rate of oxygen consumption, which was inversely correlated with plasma osmolality and urea concentration. In a separate experiment, resting rates of oxygen consumption in fully hydrated frogs receiving injections of saline or saline containing urea did not differ initially; however, upon dehydration, metabolic rates decreased sooner in the urea-loaded frogs than in control frogs. Our findings suggest an important role for urea, acting in concert with dehydration, in the metabolic regulation and energy conservation of hibernating R. sylvatica.

  6. Take the long way home: Behaviour of a neotropical frog, Allobates femoralis, in a detour task.

    Science.gov (United States)

    Munteanu, Alexandru Marian; Starnberger, Iris; Pašukonis, Andrius; Bugnyar, Thomas; Hödl, Walter; Fitch, William Tecumseh

    2016-05-01

    Detour behaviour, an individual's ability to reach its goal by taking an indirect route, has been used to test spatial cognitive abilities across a variety of taxa. Although many amphibians show a strong homing ability, there is currently little evidence of amphibian spatial cognitive flexibility. We tested whether a territorial frog, Allobates femoralis, can flexibly adjust its homing path when faced with an obstacle. We displaced male frogs from their calling sites into the centre of circular arenas and recorded their escape routes. In the first experiment we provided an arena with equally high walls. In the second experiment we doubled the height of the homeward facing wall. Finally, we provided a tube as a shortcut through the high wall. In the equal-height arena, most frogs chose to escape via the quadrant facing their former calling site. However, when challenged with different heights, nearly all frogs chose the low wall, directing their movements away from the calling site. In the "escape tunnel" experiment most frogs still chose the low wall. Our results show that displaced A. femoralis males can flexibly adjust their homing path and avoid (presumably energetically costly) obstacles, providing experimental evidence of spatial cognitive flexibility in an amphibian. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Emerging myxosporean parasites of Australian frogs take a ride with fresh fruit transport.

    Science.gov (United States)

    Hartigan, Ashlie; Peacock, Lee; Rosenwax, Alex; Phalen, David N; Slapeta, Jan

    2012-09-24

    The spread of wildlife pathogens into new geographical ranges or populations is a conservation concern for endangered species. Cystodiscus australis and Cystodiscus axonis are two species of myxosporean parasites infecting Australian frogs and tadpoles that have been recently recognised as important disease agents impacting amphibian conservation. Yet despite their importance to wildlife health, the mechanism of emergence for these parasites is unknown. We hypothesise that these parasites are capable of being accidentally translocated with their amphibian hosts in fresh produce (agricultural, horticultural and industrial) shipments into naïve environments and host populations. We surveyed 33 Australian "Banana box" frogs from Sydney fruit markets during 2011 using faecal smears and multiplex species specific PCR on DNA isolated from frog faeces or using histopathology to demonstrate the presence of both C. australis and C. axonis. One of the "Banana box" frogs, the Dainty green tree frog (Litoria gracilenta) was positive for C. australis and C. axonis in its faeces and continuously shed the parasites for eight months. We present a possible mechanism for the emergence of Cystodiscus parasites and a non-invasive screening method to be used as a diagnostic test. In the future, vigilance and communication between wildlife managers/researchers and veterinarians will provide valuable information about these parasites, their host range and true distribution. This will aid risk management assessments for threatened populations within the range of Cystodiscus parasites and ultimately enhance conservation efforts.

  8. Proteomic analysis of skin defensive factors of tree frog Hyla simplex.

    Science.gov (United States)

    Wu, Jing; Liu, Han; Yang, Hailong; Yu, Haining; You, Dewen; Ma, Yufang; Ye, Huahu; Lai, Ren

    2011-09-02

    Tree frogs produce a variety of skin defensive chemicals against many biotic and abiotic risk factors for their everyday survival. By proteomics or peptidomics and coupling transcriptome analysis with pharmacological testings, 27 peptides or proteins belonging to 9 families, which act mainly as defensive functions, were identified and characterized from skin secretions of the tree frog, Hyla simplex. They are: (1) a novel family of peptides with EGF- and VEGF-releasing activities; (2) a novel family of analgesic peptides; (3) a family of neurotoxins acting on sodium channel; (4) a snake venom-like presynaptically active neurotoxin; (5) a snake venom-like neurotoxin targeting cyclic nucleotide-gated ion channels; (6) a tachykinin-like peptide, which is the first report from tree frogs; (7) two antimicrobial peptides; (8) a alpha-1-antitrypsin-like serpin; and (9) a wasp venom-like toxin with serine protease inhibitors activity. Families of 1, 2, 4, 5, and 8 proteins or peptides are first reported in amphibians. The chemical array in the tree frog skin shares some similarities with snake venoms. Most of these components in this tree frog help defend against predators, heal wounds, or attenuate suffering.

  9. Emerging myxosporean parasites of Australian frogs take a ride with fresh fruit transport

    Directory of Open Access Journals (Sweden)

    Hartigan Ashlie

    2012-09-01

    Full Text Available Abstract Background The spread of wildlife pathogens into new geographical ranges or populations is a conservation concern for endangered species. Cystodiscus australis and Cystodiscus axonis are two species of myxosporean parasites infecting Australian frogs and tadpoles that have been recently recognised as important disease agents impacting amphibian conservation. Yet despite their importance to wildlife health, the mechanism of emergence for these parasites is unknown. We hypothesise that these parasites are capable of being accidentally translocated with their amphibian hosts in fresh produce (agricultural, horticultural and industrial shipments into naïve environments and host populations. Methods We surveyed 33 Australian “Banana box” frogs from Sydney fruit markets during 2011 using faecal smears and multiplex species specific PCR on DNA isolated from frog faeces or using histopathology to demonstrate the presence of both C. australis and C. axonis. Results One of the “Banana box” frogs, the Dainty green tree frog (Litoria gracilenta was positive for C. australis and C. axonis in its faeces and continuously shed the parasites for eight months. Conclusions We present a possible mechanism for the emergence of Cystodiscus parasites and a non-invasive screening method to be used as a diagnostic test. In the future, vigilance and communication between wildlife managers/researchers and veterinarians will provide valuable information about these parasites, their host range and true distribution. This will aid risk management assessments for threatened populations within the range of Cystodiscus parasites and ultimately enhance conservation efforts.

  10. Composition and Functional Specialists of the Gut Microbiota of Frogs Reflect Habitat Differences and Agricultural Activity

    Directory of Open Access Journals (Sweden)

    Bing-Hong Huang

    2018-01-01

    Full Text Available The physiological impact of agricultural pollution, habitat disturbance, and food source variability on amphibian remains poorly understood. By comparing the composition and predicted functions of gut microbiota of two frog species from forest and farmland, we quantified the effects of the exogenous environment and endogenous filters on gut microbiota and the corresponding functions. However, compositional differences of the gut microbiota between the frog species were not detected, even when removing roughly 80–88% of the confounding effect produced by common and shared bacteria (i.e., generalists and those taxa deemed too rare. The habitat effect accounted for 14.1% of the compositional difference of gut microbial specialists, but host and host × habitat effects were not significant. Similar trends of a significant habitat effect, at an even higher level (26.0%, for the physiological and metabolic functions of gut microbiota was predicted. A very obvious skewing of the relative abundance of functional groups toward farmland habitats reflects the highly diverse bacterial functions of farmland frogs, in particular related to pathogenic disease and pesticide degradation, which may be indication of poor adaptation or strong selective pressure against disease. These patterns reflect the impacts of agricultural activities on frogs and how such stresses may be applied in an unequal manner for different frog species.

  11. THE MOCHE BOTANICAL FROG (La rana botánica mochica

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    Donna McClelland †

    2011-06-01

    Full Text Available Plants and animals with features which identify them as supernaturals characterize the art of the Precolumbian Moche culture of northern Peru. Among these animals is a frog with feline attributes and a consistent association with manioc tubers, stalks, and plants, the Botanical Frog. The Botanical Frog appears to have been patterned on Leptodactylus pentadactylus. It is shown copulating with felines. Fine line painted vessels and ones with low relief decoration show the Botanical Frog performing as part of a ritual involving other animals and cultivated crops, suggesting that the Botanical Frog was associated with agriculture. ESPAÑOL: El arte de la cultura mochica de la costa norte del Perú presenta plantas y animales mostrando rasgos sobrenaturales. Uno de los animales es una rana con elementos felinos y asociada con tubérculos, ramas y plantas de yuca. La Rana Botánica probablemente tiene su origen en Leptodactylus pentadactylus, una rana carnívora de la selva amazónica. La Rana Botánica copula con felinos y, en vasijas pintadas con líneas finas o con escenarios representados en bajorrelieve, toma parte en ceremonias involucrando a otros animales y cosechas domésticas. Parece ser que la Rana Botánica era un ser sobrenatural asociado con la agricultura.

  12. Propulsive efficiency of frog swimming with different feet and swimming patterns

    Science.gov (United States)

    Jizhuang, Fan; Wei, Zhang; Bowen, Yuan; Gangfeng, Liu

    2017-01-01

    ABSTRACT Aquatic and terrestrial animals have different swimming performances and mechanical efficiencies based on their different swimming methods. To explore propulsion in swimming frogs, this study calculated mechanical efficiencies based on data describing aquatic and terrestrial webbed-foot shapes and swimming patterns. First, a simplified frog model and dynamic equation were established, and hydrodynamic forces on the foot were computed according to computational fluid dynamic calculations. Then, a two-link mechanism was used to stand in for the diverse and complicated hind legs found in different frog species, in order to simplify the input work calculation. Joint torques were derived based on the virtual work principle to compute the efficiency of foot propulsion. Finally, two feet and swimming patterns were combined to compute propulsive efficiency. The aquatic frog demonstrated a propulsive efficiency (43.11%) between those of drag-based and lift-based propulsions, while the terrestrial frog efficiency (29.58%) fell within the range of drag-based propulsion. The results illustrate the main factor of swimming patterns for swimming performance and efficiency. PMID:28302669

  13. Asplenium bird’s nest ferns in rainforest canopies are climate-contingent refuges for frogs

    Directory of Open Access Journals (Sweden)

    Brett R. Scheffers

    2014-12-01

    Full Text Available Epiphytes are important for canopy dwelling organisms because they provide a cool and moist microhabitat in the relatively hot and dry canopy. Here we examine whether epiphytic Asplenium ferns act as important habitats for arboreal frogs. We conducted extensive fern and habitat surveys for frogs in the Philippines, and complimented these surveys with roaming day and night canopy surveys to identify the full extent of habitat use across the vertical strata. We artificially dried ferns of various sizes to identify relationships between water and temperature buffering. Ferns are the preferred diurnal microhabitat and breeding habitat for arboreal frogs. A strong positive relationship exists between fern size and frog usage and abundance. Our drying experiments show that large ferns buffer maximum temperatures and reduce variability in temperatures, and buffering is directly linked to their hydration. Frogs are likely using large ferns for their moist, cool, environments for breeding and daytime retreat, which supports the buffered microhabitat hypothesis—these plants promote species coexistence through habitat creation and amelioration of physical stress. However, drying experiments suggest that this buffering is contingent on regular rainfall. Altered rainfall regimes could lead to the unexpected loss of the functional capacity of these important fern habitats.

  14. Single and interactive effects of malathion, overwintered green frog tadpoles, and cyanobacteria on gray treefrog tadpoles.

    Science.gov (United States)

    Mackey, Mark J; Boone, Michelle D

    2009-03-01

    Amphibian population declines around the world are associated with invasive species, pesticides, pathogens, habitat destruction, or a combination of factors. Because contamination is widespread, it represents a relevant environmental stress that can affect the ability of organisms to deal with other factors present in the environment. We examined the effects of the insecticide malathion, larger tadpole competitors (green frogs, Rana clamitans), and a toxic cyanobacteria (Anabaena spp.) on tadpoles of Cope's gray treefrog (Hyla chrysoscelis) reared from hatching through metamorphosis in outdoor mesocosms. The response of mass at metamorphosis and time to metamorphosis was significantly affected by exposure to malathion and presence of overwintered green frog tadpoles. Malathion generally led to increased mass at metamorphosis, earlier time to metamorphosis, and increased activity during larval development. These results likely stem from short-term increases in periphyton associated with malathion exposure (although these effects were nonsignificant). Exposure of gray treefrogs to overwintered green frog tadpoles led to an earlier time to metamorphosis without differences in mass at metamorphosis and was associated with increased activity in gray treefrogs. Survival of gray treefrogs was significantly affected by an interaction of green frog and malathion, indicating nonadditive effects of these treatments. Exposure to cyanobacteria had a significant negative effect on green frogs but no effect on treefrogs. Malathion had the strongest effect on the community, but our results indicated that some factors can interact in ways not predicted by single factors alone.

  15. The effect of food properties on grasping and manipulation in the aquatic frog, Xenopus laevis.

    Science.gov (United States)

    Anzeraey, Aude; Aumont, Madeleine; Decamps, Thierry; Herrel, Anthony; Pouydebat, Emmanuelle

    2017-10-05

    The ability to grasp an object is fundamental from an evolutionary perspective. Involved in many daily activities, grasping has been extensively studied in primates and other mammals. Yet, other groups of tetrapods, including anurans, have also evolved significant forelimb prehensile capacities that are often thought to have originated in an arboreal context. However, grasping is also observed in aquatic species. Yet, how aquatic frogs use their forelimbs to capture and manipulate prey remains largely unknown. The aim of this study is to explore how the grasping and manipulation of food items in aquatic frogs is impacted by food properties such as size and mobility. To do so we use the aquatic frog Xenopus laevis and quantified the use of the hands and fingers while processing mobile and stationary prey of different sizes (small, intermediate, and large prey). Our results show that X. laevis is able to individualize the digits and that the mobility and the length of the prey significantly influence the kind of grasping pattern used. Grasping abilities are thus not specific to terrestrial, nor arboreal species. These results illustrate how prey properties impact grasping and manipulation strategies in an aquatic frog and shed further light on the ecological contexts that may have given rise to the origin of grasping in frogs. © 2017. Published by The Company of Biologists Ltd.

  16. Propulsive efficiency of frog swimming with different feet and swimming patterns

    Directory of Open Access Journals (Sweden)

    Fan Jizhuang

    2017-04-01

    Full Text Available Aquatic and terrestrial animals have different swimming performances and mechanical efficiencies based on their different swimming methods. To explore propulsion in swimming frogs, this study calculated mechanical efficiencies based on data describing aquatic and terrestrial webbed-foot shapes and swimming patterns. First, a simplified frog model and dynamic equation were established, and hydrodynamic forces on the foot were computed according to computational fluid dynamic calculations. Then, a two-link mechanism was used to stand in for the diverse and complicated hind legs found in different frog species, in order to simplify the input work calculation. Joint torques were derived based on the virtual work principle to compute the efficiency of foot propulsion. Finally, two feet and swimming patterns were combined to compute propulsive efficiency. The aquatic frog demonstrated a propulsive efficiency (43.11% between those of drag-based and lift-based propulsions, while the terrestrial frog efficiency (29.58% fell within the range of drag-based propulsion. The results illustrate the main factor of swimming patterns for swimming performance and efficiency.

  17. Phylogenomics reveals rapid, simultaneous diversification of three major clades of Gondwanan frogs at the Cretaceous-Paleogene boundary.

    Science.gov (United States)

    Feng, Yan-Jie; Blackburn, David C; Liang, Dan; Hillis, David M; Wake, David B; Cannatella, David C; Zhang, Peng

    2017-07-18

    Frogs (Anura) are one of the most diverse groups of vertebrates and comprise nearly 90% of living amphibian species. Their worldwide distribution and diverse biology make them well-suited for assessing fundamental questions in evolution, ecology, and conservation. However, despite their scientific importance, the evolutionary history and tempo of frog diversification remain poorly understood. By using a molecular dataset of unprecedented size, including 88-kb characters from 95 nuclear genes of 156 frog species, in conjunction with 20 fossil-based calibrations, our analyses result in the most strongly supported phylogeny of all major frog lineages and provide a timescale of frog evolution that suggests much younger divergence times than suggested by earlier studies. Unexpectedly, our divergence-time analyses show that three species-rich clades (Hyloidea, Microhylidae, and Natatanura), which together comprise ∼88% of extant anuran species, simultaneously underwent rapid diversification at the Cretaceous-Paleogene (K-Pg) boundary (KPB). Moreover, anuran families and subfamilies containing arboreal species originated near or after the KPB. These results suggest that the K-Pg mass extinction may have triggered explosive radiations of frogs by creating new ecological opportunities. This phylogeny also reveals relationships such as Microhylidae being sister to all other ranoid frogs and African continental lineages of Natatanura forming a clade that is sister to a clade of Eurasian, Indian, Melanesian, and Malagasy lineages. Biogeographical analyses suggest that the ancestral area of modern frogs was Africa, and their current distribution is largely associated with the breakup of Pangaea and subsequent Gondwanan fragmentation.

  18. Bioavailability and tissue distribution of Dechloranes in wild frogs (Rana limnocharis) from an e-waste recycling area in Southeast China.

    Science.gov (United States)

    Li, Long; Wang, Wenyue; Lv, Quanxia; Ben, Yujie; Li, Xinghong

    2014-03-01

    Dechlorane Plus (DP), a flame retardant used as an alternative to decabromodiphenylether, has been frequently detected in organisms, indicating its bioaccumulation and biomagnification potential in aquatic and terrestrial species. However, little data is available on the bioaccumulation of DP in amphibians. Dechlorane Plus and its analogs (DPs) were detected in the liver, muscle and brain tissues of wild frogs (Rana limnocharis), which were collected from an e-waste recycling site, Southeast China. DP, Mirex, Dec 602 and a dechlorinated compound of DP (anti-Cl11-DP) varied in the range of 2.01-291, 0.650-179, 0.260-12.4, and not detected (nd)-8.67 ng/g lipid weight, respectively. No difference of tissue distribution was found for syn-DP, Mirex and Dec 602 between the liver and muscle tissue (liver/muscle concentration ratio close to 1, p > 0.05). However, higher retention was observed for anti-DP and anti-Cl11-DP in the frog muscle relative to the liver tissue (liver/muscle concentration ratio 1, p < 0.05), and the molecular weight was a key factor impacting the extent of the blood-brain barrier. Compared to levels in the muscle and brain tissue, a preferential enrichment of syn-DP was observed in the liver tissue, suggesting the occurrence of stereo-selective bioaccumulation in the wild frog. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  19. Pharmacological studies of charge movement in frog skeletal muscle.

    Science.gov (United States)

    Hui, C S

    1983-04-01

    Charge movements in frog twitch fibres were studied using the three-microelectrode voltage-clamp technique. In a solution made moderately hypertonic with 350 mM-sucrose, fibre contraction was effectively blocked and a secondary hump appeared in the decay phase of the 'on' part of charge movement. At small depolarizations, the hump (Q gamma) is small and slow. As depolarization is increased, Q gamma becomes larger in magnitude and faster in kinetics until it merges with the main part of charge movement (Q beta). As the fibre is perfused extracellularly with a test solution saturated with dantrolene sodium, Q gamma disappears in about 30 min whereas the kinetics of Q beta are slowed down. After equilibration in the dantrolene sodium solution, the total moveable charge is reduced by about 20%, which could very well be the charge carried by Q gamma. Tetracaine also suppresses Q gamma but does not seem to have any effect on the kinetics of Q beta. The suppression of Q gamma appears to be dose-dependent, with complete abolition occurring at about 4 mM-tetracaine. Dissection of charge movement with tetracaine indicates that Q gamma might be bell-shaped and capacitive in nature. Q beta and Q gamma might be two distinct species of charge and Q gamma would probably be more closely associated with calcium release from the sarcoplasmic reticulum.

  20. Antimicrobial properties of the skin secretions of frogs

    Directory of Open Access Journals (Sweden)

    Adriaan J. Esterhuyse

    2012-05-01

    Full Text Available Antimicrobial resistance results in increased morbidity and mortality, and increased health-care costs. Therefore the need to develop new classes of antibiotics is indispensable. Antimicrobial peptides are a relatively new class of potential antibiotics which are fast acting, possess broad-spectrum activity and are able to escape many of the currently known mechanisms of drug resistance. They have been shown to be active against Gram-negative and Gram-positive bacteria, fungi, enveloped viruses and even cancer cells. However, toxicity to healthy host cells remains a concern and has affected the clinical development of therapeutics based on antimicrobial peptides. The purpose of this review is to discuss recent advances in research focused on antimicrobial peptides from frogs and the challenges in conducting research in this area in southern Africa. An extensive literature review of relevant articles published between 1980 and the present was conducted using PubMed, ScienceDirect, Sabinet, Elsevier and GoogleScholar. There has been little research done on anurans from southern Africa which are endemic to the region, and there is therefore a need to focus on this group for the purposes of bioprospecting for potentially new antimicrobial peptide compounds.

  1. Transcriptome profile of the green odorous frog (Odorrana margaretae).

    Science.gov (United States)

    Qiao, Liang; Yang, Weizhao; Fu, Jinzhong; Song, Zhaobin

    2013-01-01

    Transcriptome profiles provide a practical and inexpensive alternative to explore genomic data in non-model organisms, particularly in amphibians where the genomes are very large and complex. The odorous frog Odorranamargaretae (Anura: Ranidae) is a dominant species in the mountain stream ecosystem of western China. Limited knowledge of its genetic background has hindered research on this species, despite its importance in the ecosystem and as biological resources. Here we report the transcriptome of O. margaretae in order to establish the foundation for genetic research. Using an Illumina sequencing platform, 62,321,166 raw reads were acquired. After a de novo assembly, 37,906 transcripts were obtained, and 18,933 transcripts were annotated to 14,628 genes. We functionally classified these transcripts by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). A total of 11,457 unique transcripts were assigned to 52 GO terms, and 1,438 transcripts were assigned to 128 KEGG pathways. Furthermore, we identified 27 potential antimicrobial peptides (AMPs), 50,351 single nucleotide polymorphism (SNP) sites, and 2,574 microsatellite DNA loci. The transcriptome profile of this species will shed more light on its genetic background and provide useful tools for future studies of this species, as well as other species in the genus Odorrana. It will also contribute to the accumulation of amphibian genomic data.

  2. Sexual selection drives speciation in an Amazonian frog

    Science.gov (United States)

    Boul, K.E.; Funk, W.C.; Darst, C.R.; Cannatella, D.C.; Ryan, M.J.

    2007-01-01

    One proposed mechanism of speciation is divergent sexual selection, whereby divergence in female preferences and male signals results in behavioural isolation. Despite the appeal of this hypothesis, evidence for it remains inconclusive. Here, we present several lines of evidence that sexual selection is driving behavioural isolation and speciation among populations of an Amazonian frog (Physalaemus petersi). First, sexual selection has promoted divergence in male mating calls and female preferences for calls between neighbouring populations, resulting in strong behavioural isolation. Second, phylogenetic analysis indicates that populations have become fixed for alternative call types several times throughout the species' range, and coalescent analysis rejects genetic drift as a cause for this pattern, suggesting that this divergence is due to selection. Finally, gene flow estimated with microsatellite loci is an average of 30 times lower between populations with different call types than between populations separated by a similar geographical distance with the same call type, demonstrating genetic divergence and incipient speciation. Taken together, these data provide strong evidence that sexual selection is driving behavioural isolation and speciation, supporting sexual selection as a cause for speciation in the wild. ?? 2006 The Royal Society.

  3. Synthesis of nanoparticles with frog foam nest proteins

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hyo-Jick, E-mail: choihc@ucmail.uc.edu; Ebersbacher, Charles F. [University of Cincinnati, School of Energy, Environmental, Biological and Medical Engineering (United States); Myung, Nosang V. [University of California, Riverside, Department of Chemical and Environmental Engineering (United States); Montemagno, Carlo D., E-mail: montemcd@ucmail.uc.edu [University of Cincinnati, School of Energy, Environmental, Biological and Medical Engineering (United States)

    2012-09-15

    Microemulsions provide an efficient means of synthesizing monodispersed nanoparticles. Recent studies have demonstrated potential problems of surfactant due to the interaction with nanoparticles/precursors. To solve the problems, various types of chemical surfactants have been tested, but natural biosurfactants have not received a great deal of attention in engineering application. Here, we report the formation of microemulsions using frog foam nest protein, ranaspumin-2 (RSN-2), based on the hypothesis that RSN-2 assembles at the water-oil interface as a result of conformational change into an extended form. Fluorescence spectroscopic studies showed that RSN-2 undergoes a reversible transition between extended and globular conformation in foams/microemulsions and aqueous solution, respectively. Microemulsions were formulated with RSN-2 to synthesize 8-10 nm superparamagnetic iron oxide nanoparticles by mixing precursor-containing microemulsions with base-containing microemulsions. RSN-2 proteins were recovered from microemulsions and found to be recycled to make foams and microemulsions. Fluorescence spectroscopic analyses showed that RSN-2 maintained its mechanical agitation-induced amphiphilicity throughout multiple foaming/defoaming processes. These results suggest that conformational flexibility and structural stability of RSN-2 in aggressive environments enable the recycled use of RSN-2, elucidating the cost-effective advantage.

  4. A multigene species tree for Western Mediterranean painted frogs (Discoglossus).

    Science.gov (United States)

    Pabijan, Maciej; Crottini, Angelica; Reckwell, Dennis; Irisarri, Iker; Hauswaldt, J Susanne; Vences, Miguel

    2012-09-01

    Painted frogs (Discoglossus) are an anuran clade that originated in the Upper Miocene. Extant species are morphologically similar and have a circum-Mediterranean distribution. We assembled a multilocus dataset from seven nuclear and four mitochondrial genes for several individuals of all but one of the extant species and reconstructed a robust phylogeny by applying a coalescent-based species-tree method and a concatenation approach, both of which gave congruent results. The earliest phylogenetic split within Discoglossus separates D. montalentii from a clade comprising all other species. Discoglossus montalentii is monophyletic for haplotype variation at all loci and has distinct morphological, bioacoustic and karyotypic characters. We find moderate support for a sister-group relationship between the Iberian taxa and the Moroccan D. scovazzi, and high support for a D. pictus -D. sardus clade distributed around the Tyrrhenian basin. Topological discordance among gene trees during the speciation of D. galganoi, D. scovazzi, D. pictus and D. sardus is interpreted as the consequence of nearly simultaneous, vicariant diversification. The timing of these events is unclear, but possibly coincided with the final geotectonic rearrangement of the Western Mediterranean in the Middle Miocene or later during the Messinian salinity crisis. The Iberian taxa D. galganoi galganoi and D. g. jeanneae are reciprocally monophyletic in mitochondrial DNA but not in nuclear gene trees, and are therefore treated as subspecies of D. galganoi. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Brazilian marsupial frogs are diphyletic (Anura: Hemiphractidae: Gastrotheca).

    Science.gov (United States)

    Blackburn, David C; Duellman, William E

    2013-09-01

    Molecular phylogenetic analyses based on expanded taxonomic and geographic sampling support the monophyly of the marsupial frog genera (family Hemiphractidae), resolve six geographically circumscribed lineages within Gastrotheca, and, for the first time, reveal that two divergent lineages of Gastrotheca inhabit the Atlantic Coastal Forests of Brazil. Within Gastrotheca, the earliest diverging clade is confined to northeastern Brazil, whereas the three subsequent diverging lineages are restricted to northern Venezuela (G. walkeri), southeastern Brazil, and northwestern South America. All species in these clades inhabit humid forests at low to mid-elevations, and their life histories are characterized by lacking free-living tadpoles (i.e., direct development). Two derived clades inhabit the Andes, and both contain species with either direct development or tadpoles. One Andean clade of Gastrotheca ranges in the high Andes from Colombia to extreme northern Peru, whereas the other clade inhabits high elevations in the Andes of southern Ecuador, Peru, and Bolivia, and lower elevations in the Andes of northwestern Argentina. The presence of two non-sister lineages on each side of the Amazon Basin suggests that vicariance across this central region played an important role in diversification within Gastrotheca. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Novel analgesic peptides from the tree frog of Hyla japonica.

    Science.gov (United States)

    Zhu, Yuqin; Li, Zhengtao; Liu, Han; He, Xiaoqin; Zhang, Yun; Jin, Jieqiong; Che, Jing; Li, Cheng; Chen, Wenlin; Lai, Ren; Liu, Jingze

    2014-04-01

    Two novel analgesic peptides (Analgesin-HJ, FWPVI-NH2 and Analgesin-HJ(I5T), FWPVT-NH2) were identified from the skin of the tree frog, Hyla japonica. There are 171 amino acid residues in the precursor encoding analgesin-HJs. The precursor contains 10 copies of mature peptide, which include 9 copies of analgesin-HJ and one copy of analgesin-HJ(I5T). Results from analgesic experiments using mice models including abdominal writhing induced by acetic acid, formalin-induced paw licking, and thermal pain test indicated that this two peptides exerted comparable analgesic activities with morphine. In addition, they had ability to inhibit inflammatory factor secretion induced by lipopolysaccharides (LPS). Considering their easy production, storage, transfer and potential analgesic activity, analgesin-HJs might be exciting leading compounds or templates for the development of novel analgesic agent. In addition, this study might facilitate to understand skin defensive mechanism of amphibians. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  7. Immune challenges and visual signalling in tree frogs

    Science.gov (United States)

    Desprat, Julia L.; Lengagne, Thierry; Mondy, Nathalie

    2017-04-01

    In animals, mate-choice is often based on sexual signals that carry information and help the receiver make the best choice to improve the receiver's fitness. Orange visual sexual signals have been hypothesised to carry immune information because they are often due to carotenoid pigments which are also involved in immunity response. Although many studies have focused on the direct relationships between coloration and immunocompetence, few studies have simultaneously studied immunocompetent response and coloration variation after an immune challenge. We tested this hypothesis on starved and ad libitum-fed males of the European tree frog Hyla arborea. Our results show that male coloration is not a reliable indicator of its immune response capacity in this species. However, after an immune challenge induced by a PHA ( Phaseolus vulgaris phytohaemagglutinin) injection, starved males presented a significant coloration loss and this alteration was related to the immune response intensity. Taken together, these results suggest that the brighter (lighter) coloration may be used as a cue by female to exclude males with a recent immune challenge, due to diseases or parasites for example.

  8. Environmental constraints and call evolution in torrent-dwelling frogs.

    Science.gov (United States)

    Goutte, Sandra; Dubois, Alain; Howard, Samuel D; Marquez, Rafael; Rowley, Jodi J L; Dehling, J Maximilian; Grandcolas, Philippe; Rongchuan, Xiong; Legendre, Frédéric

    2016-04-01

    Although acoustic signals are important for communication in many taxa, signal propagation is affected by environmental properties. Strong environmental constraints should drive call evolution, favoring signals with greater transmission distance and content integrity in a given calling habitat. Yet, few empirical studies have verified this prediction, possibly due to a shortcoming in habitat characterization, which is often too broad. Here we assess the potential impact of environmental constraints on the evolution of advertisement call in four groups of torrent-dwelling frogs in the family Ranidae. We reconstruct the evolution of calling site preferences, both broadly categorized and at a finer scale, onto a phylogenetic tree for 148 species with five markers (∼3600 bp). We test models of evolution for six call traits for 79 species with regard to the reconstructed history of calling site preferences and estimate their ancestral states. We find that in spite of existing morphological constraints, vocalizations of torrent-dwelling species are most probably constrained by the acoustic specificities of torrent habitats and particularly their high level of ambient noise. We also show that a fine-scale characterization of calling sites allows a better perception of the impact of environmental constraints on call evolution. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  9. Adaptogenic and cardioprotective action of ashwagandha in rats and frogs.

    Science.gov (United States)

    Dhuley, J N

    2000-04-01

    Pharmacological and metabolic effects of ashwagandha (Withania somnifera L. (Solanaceae)) used in Ayurveda as a herbal tonic and health food were studied. Ashwagandha was shown to increase swimming time in rats in physical working capacity test, i.e. rats swimming endurance test. Significant increase in relative heart weight and glycogen content in myocardium and liver was also observed in ashwagandha treated group. Ashwagandha treatment increased the duration of contractility in functional test for the resistance of frog heart muscle towards the toxic action of strophanthin-K. Ashwaaandha treatment also resulted in significant increase in coagulation time which attains normalcy 7 days after cessation of treatment. Ashwagandha possesses no toxicity up to a dose of (100 mg/kg; p.o. for 180 days) and does not cause significant changes in biochemical parameters in the blood serum of rats. Increase in catecholamine content in the heart and aortic tissues and their decrease in adrenal glands are unfavourable effects of high doses of ashwagandha. On the basis of these observations, it was concluded that ashwagandha possesses adaptogenic, cardiotropic, cardioprotective and anticoagulant properties.

  10. Transcriptome profile of the green odorous frog (Odorrana margaretae.

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    Liang Qiao

    Full Text Available Transcriptome profiles provide a practical and inexpensive alternative to explore genomic data in non-model organisms, particularly in amphibians where the genomes are very large and complex. The odorous frog Odorranamargaretae (Anura: Ranidae is a dominant species in the mountain stream ecosystem of western China. Limited knowledge of its genetic background has hindered research on this species, despite its importance in the ecosystem and as biological resources. Here we report the transcriptome of O. margaretae in order to establish the foundation for genetic research. Using an Illumina sequencing platform, 62,321,166 raw reads were acquired. After a de novo assembly, 37,906 transcripts were obtained, and 18,933 transcripts were annotated to 14,628 genes. We functionally classified these transcripts by Gene Ontology (GO and Kyoto Encyclopedia of Genes and Genomes (KEGG. A total of 11,457 unique transcripts were assigned to 52 GO terms, and 1,438 transcripts were assigned to 128 KEGG pathways. Furthermore, we identified 27 potential antimicrobial peptides (AMPs, 50,351 single nucleotide polymorphism (SNP sites, and 2,574 microsatellite DNA loci. The transcriptome profile of this species will shed more light on its genetic background and provide useful tools for future studies of this species, as well as other species in the genus Odorrana. It will also contribute to the accumulation of amphibian genomic data.

  11. Antibody dependent enhancement of frog virus 3 infection

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    Penny Emily

    2010-02-01

    Full Text Available Abstract Background Viruses included in the family Iridoviridae are large, icosahedral, dsDNA viruses that are subdivided into 5 genera. Frog virus 3 (FV3 is the type species of the genus Ranavirus and the best studied iridovirus at the molecular level. Typically, antibodies directed against a virus act to neutralize the virus and limit infection. Antibody dependent enhancement occurs when viral antibodies enhance infectivity of the virus rather than neutralize it. Results Here we show that anti-FV3 serum present at the time of FV3 infection enhances infectivity of the virus in two non-immune teleost cell lines. We found that antibody dependent enhancement of FV3 was dependent on the Fc portion of anti-FV3 antibodies but not related to complement. Furthermore, the presence of anti-FV3 serum during an FV3 infection in a non-immune mammalian cell line resulted in neutralization of the virus. Our results suggest that a cell surface receptor specific to teleost cell lines is responsible for the enhancement. Conclusions This report represents the first evidence of antibody dependent enhancement in iridoviruses. The data suggests that anti-FV3 serum can either neutralize or enhance viral infection and that enhancement is related to a novel antibody dependent enhancement pathway found in teleosts that is Fc dependent.

  12. FROG ASSEMBLAGE ASSOCIATED WITH BROMELIADS IN A SANDY COASTAL PLAIN IN THE STATE OF ESPÍRITO SANTO, SOUTHEASTERN BRAZIL

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    MARCIO MARQUES MAGESKI

    Full Text Available ABSTRACT Amphibians may use bromeliads for reproduction (i.e., bromeligenous species or only for refuge and foraging (i.e., bromelicolous species. The partition of bromeliad resources is essential to maintain the coexistence of the associated assemblages. We sampled 913 bromeliads in a sandy coastal plain (i.e., restinga habitat in southeastern Brazil and found 234 frogs belonging to seven species. One of the frog species was bromeligenous and the other six were facultative bromelicolous. The bromeliads of the genus Aechmea were the most frequently used by frogs. The low degree of frog occupancy of bromeliads (26% suggests habitat segregation. Our study highlights the importance of maintenance of bromeliad species for conservation of the associated frog assemblages.

  13. A success model and implementation on examining teacher’s attitude in using frog virtual learning environment

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    Wan Rozaini Sheik Osman

    2017-12-01

    Full Text Available The Frog Virtual Learning Environment (Frog VLE together with school administrators, teachers, students and parents has formed the concept of a virtual community within the school environment. The research uses a qualitative approach that involves interviewing four selected teachers in a primary school located in the district of Baling/ Sik, Kedah. The study employs a structured questionnaire as an interview protocol instrument. The questionnaires were also distributed to sixteen other teachers to compare the responses. The findings showed that teachers were using Frog VLE application and it helps in teaching and learning. Frog VLE also motivates teachers to teach better. However, not all teachers are comfortable using it because there are many obstacles and constraints that teachers face when applying them. The analysis of result from the teacher’s attitude indicated that there was an important relationship between the teacher’s basic knowledge of ICT and the skills in accessing the Frog VLE.

  14. Discovery of skin alkaloids in a miniaturized eleutherodactylid frog from Cuba.

    Science.gov (United States)

    Rodríguez, Ariel; Poth, Dennis; Schulz, Stefan; Vences, Miguel

    2011-06-23

    Four phylogenetically independent lineages of frogs are currently known to sequester lipid-soluble skin alkaloids for which a dietary source has been demonstrated. We report here a remarkable fifth such instance, in Eleutherodactylus iberia and Eleutherodactylus orientalis, two species of miniaturized frogs of the family Eleutherodactylidae from Cuba. Six pumiliotoxins and two indolizidines were found in E. iberia, one of the smallest frogs in the world and characterized by a contrasting colour pattern for which we hypothesize an aposematic function. Analyses of stomach content indicated a numerical prevalence of mites with an important proportion of oribatids-a group of arthropods known to contain one of the pumiliotoxins detected in E. iberia. This suggests that miniaturization and specialization to small prey may have favoured the acquisition of dietary skin alkaloids in these amphibians.

  15. Condensation onto the skin as a means for water gain by tree frogs in tropical Australia.

    Science.gov (United States)

    Tracy, Christopher R; Laurence, Nathalie; Christian, Keith A

    2011-10-01

    Green tree frogs, Litoria caerulea, in the wet-dry tropics of northern Australia remain active during the dry season with apparently no available water and temperatures that approach their lower critical temperature. We hypothesized that this surprising activity might be because frogs that are cooled during nighttime activity gain water from condensation by returning to a warm, humid tree hollow. We measured the mass gained when a cool frog moved into either a natural or an artificial hollow. In both hollows, water condensed on cool L. caerulea, resulting in water gains of up to 0.93% of body mass. We estimated that the water gained was more than the water that would be lost to evaporation during activity. The use of condensation as a means for water gain may be a significant source of water uptake for species like L. caerulea that occur in areas where free water is unavailable over extended periods.

  16. An efficient method of wavelength interval selection based on random frog for multivariate spectral calibration

    Science.gov (United States)

    Yun, Yong-Huan; Li, Hong-Dong; Wood, Leslie R. E.; Fan, Wei; Wang, Jia-Jun; Cao, Dong-Sheng; Xu, Qing-Song; Liang, Yi-Zeng

    2013-07-01

    Wavelength selection is a critical step for producing better prediction performance when applied to spectral data. Considering the fact that the vibrational and rotational spectra have continuous features of spectral bands, we propose a novel method of wavelength interval selection based on random frog, called interval random frog (iRF). To obtain all the possible continuous intervals, spectra are first divided into intervals by moving window of a fix width over the whole spectra. These overlapping intervals are ranked applying random frog coupled with PLS and the optimal ones are chosen. This method has been applied to two near-infrared spectral datasets displaying higher efficiency in wavelength interval selection than others. The source code of iRF can be freely downloaded for academy research at the website: http://code.google.com/p/multivariate-calibration/downloads/list.

  17. Pesticide concentrations in frog tissue and wetland habitats in a landscape dominated by agriculture.

    Science.gov (United States)

    Smalling, Kelly L; Reeves, Rebecca; Muths, Erin; Vandever, Mark; Battaglin, William A; Hladik, Michelle L; Pierce, Clay L

    2015-01-01

    Habitat loss and exposure to pesticides are likely primary factors contributing to amphibian decline in agricultural landscapes. Conservation efforts have attempted to restore wetlands lost through landscape modifications to reduce contaminant loads in surface waters and providing quality habitat to wildlife. The benefits of this increased wetland area, perhaps especially for amphibians, may be negated if habitat quality is insufficient to support persistent populations. We examined the presence of pesticides and nutrients in water and sediment as indicators of habitat quality and assessed the bioaccumulation of pesticides in the tissue of two native amphibian species Pseudacris maculata (chorus frogs) and Lithobates pipiens (leopard frogs) at six wetlands (3 restored and 3 reference) in Iowa, USA. Restored wetlands are positioned on the landscape to receive subsurface tile drainage water while reference wetlands receive water from overland run-off and shallow groundwater sources. Concentrations of the pesticides frequently detected in water and sediment samples were not different between wetland types. The median concentration of atrazine in surface water was 0.2 μg/L. Reproductive abnormalities in leopard frogs have been observed in other studies at these concentrations. Nutrient concentrations were higher in the restored wetlands but lower than concentrations thought lethal to frogs. Complex mixtures of pesticides including up to 8 fungicides, some previously unreported in tissue, were detected with concentrations ranging from 0.08 to 1,500 μg/kg wet weight. No significant differences in pesticide concentrations were observed between species, although concentrations tended to be higher in leopard frogs compared to chorus frogs, possibly because of differences in life histories. Our results provide information on habitat quality in restored wetlands that will assist state and federal agencies, landowners, and resource managers in identifying and implementing

  18. Reactivity of metallothioneins of frog Rana ridibunda treated by copper and zinc ions.

    Science.gov (United States)

    Falfushynska, H I; Romanchuk, L D; Stoliar, O B

    2010-01-01

    The metal-buffering and stress proteins metallothioneins (MTs) of frog are characterised by unusually high content of copper as for vertebrate animals and instability that was shown in our previous studies. They easily lost copper and especially zinc under unfavourable conditions. The aim of this study was to examine the reactivity of SH groups in the MTs from the liver of frog Rana ridibunda after the effect of Cu2+ (0.01 mg/l) and Zn2+ (0.1 mg/l) ions on the organism during 14 days. The alpha- and beta-domains of MTs with molecular weights of about 4 kDa were separated by the size-exclusion chromatography on Sephadex G-50. Unlike higher vertebrates, frogs demonstrated higher reactivity of alpha-domain than beta-domain with the Ellman's reagent (DTNB). The signs of partial oxidations in beta-domain included the creation of by-products with molecular weight about 12 kDa, low reactivity of SH-groups, and typical of -S-S-bonds peculiarities of UV-spectra. The effect of both metal ions on frog provoked the elevation of SH-groups reactivity in a-domain with the appearance of by-product with molecular weight of 16 kDa and its reduction in beta-domain. The incubation of MTs of control animals with 0.5 and 5.0 mM of H2O2 did not affect its chromatographic characteristics. In the frogs loaded by Cu2+ and Zn2+ the effect of 5.0 mM H2O2 on MTs provoked the release of 4 kDa product. So the alpha-domain is responsible for the increased release of metals from injured MTs in frogs, whereas extremely high oxidizability of beta-domain makes its participation in the exchange of metals elusive and provokes the aggregation of MTs.

  19. Functional analysis for gut microbes of the brown tree frog (Polypedates megacephalus) in artificial hibernation.

    Science.gov (United States)

    Weng, Francis Cheng-Hsuan; Yang, Yi-Ju; Wang, Daryi

    2016-12-22

    Annual hibernation is an adaptation that helps many animals conserve energy during food shortage in winter. This natural cycle is also accompanied by a remodeling of the intestinal immune system, which is an aspect of host biology that is both influenced by, and can itself influence, the microbiota. In amphibians, the bacteria in the intestinal tract show a drop in bacterial counts. The proportion of pathogenic bacteria is greater in hibernating frogs than that found in nonhibernating frogs. This suggests that some intestinal gut microbes in amphibians can be maintained and may contribute to the functions in this closed ecosystem during hibernation. However, these results were derived from culture-based approaches that only covered a small portion of bacteria in the intestinal tract. In this study, we use a more comprehensive analysis, including bacterial appearance and functional prediction, to reveal the global changes in gut microbiota during artificial hibernation via high-throughput sequencing technology. Our results suggest that artificial hibernation in the brown tree frog (Polypedates megacephalus) could reduce microbial diversity, and artificially hibernating frogs tend to harbor core operational taxonomic units that are rarely distributed among nonhibernating frogs. In addition, artificial hibernation increased significantly the relative abundance of the red-leg syndrome-related pathogenic genus Citrobacter. Furthermore, functional predictions via PICRUSt and Tax4Fun suggested that artificial hibernation has effects on metabolism, disease, signal transduction, bacterial infection, and primary immunodeficiency. We infer that artificial hibernation may impose potential effects on primary immunodeficiency and increase the risk of bacterial infections in the brown tree frog.

  20. Validation of a functional remission threshold for the Functional Remission of General Schizophrenia (FROGS) scale.

    Science.gov (United States)

    Boyer, Laurent; Richieri, Raphaëlle; Guedj, Eric; Faget-Agius, Catherine; Loundou, Anderson; Llorca, Pierre-Michel; Auquier, Pascal; Lançon, Christophe

    2013-10-01

    The aim of this study was to develop a functional remission threshold for the Functional Remission Of General Schizophrenia (FROGS) scale, and test its validity regarding clinical and quality of life outcomes. Cross-sectional study. Schizophrenia according to DSM-IV-TR criteria. Functioning was assessed using the FROGS and the Global Assessment of Functioning (GAF) scales; psychotic symptoms using the Positive and Negative Syndrome Scale; memory, attention, and executive functions were assessed using the California Verbal Learning Test, the D2 attention task, the Stroop color-word test, the verbal fluency test, the Trail Making Test A and B and the Wechsler Adult Intelligence Scale; and quality of life using the schizophrenia quality of life (S-QoL 18) scale. A logistic regression analysis including the different dimensions of the FROGS was used to create a composite score to classify patients into remitted and non-remitted according a gold standard (cut-off: GAF>= 61). Receiver operating characteristics analyses were then performed to determine the area under the curve (AUC). Of 137 patients enrolled, 26 were functionally remitted and 111 were not remitted according to GAF score. The AUC for the combination of the FROGS's dimensions to detect functional remission was 0.903 (p<0.001). Sensitivity and specificity for the combination of the FROGS dimensions using the Youden index were 88.5 [69.8; 97.6] and 81.1 [72.5; 87.9], respectively. Validity of this combination was satisfactory. Patients in functional remission had a lower severity of the disease, especially for PANSS negative (p<0.001) and general psychopathology (p<0.001) symptoms. Only two cognitive functions (i.e. fluency and episodic memory) were improved in remitted patients. Higher quality of life levels were globally associated with better functioning. These findings provide for first accurate FROGS thresholds to detect functional remission in schizophrenia. Copyright © 2013 Elsevier Inc. All rights

  1. Transdifferentiation of pigmented epithelium induced by the influence of lens epithelium in frogs.

    Science.gov (United States)

    Lopashov, G V

    1983-01-01

    The influence of lens epithelium (LE) of adult frogs on the character of transdifferentiation of retinal pigmented epithelium (RPE) of adult frogs and tadpoles of Rana temporaria has been studied. After a period of intense proliferation RPE cultured in vivo in contact with LE in the tadpole orbit almost exclusively transforms into retina. RPE precultivated in vitro in contact with LE for three days in protein-free medium does not manifest cell divisions and mostly transdifferentiates into lentoids. The problem of the relative significance of inducing determinants and the role of activation or inhibition of proliferation in transdifferentiation is discussed.

  2. [Optical mapping of chronotopography of excitation of the frog heart ventricle epicardial surface in sinus rhythm].

    Science.gov (United States)

    abramochkin, D V; Rozenshtraukh, L V

    2008-04-01

    Two points of early activation were shown on the surface of the frog Rana temporaria ventricle using optical mapping technique. These points are located on the left and right ventricular surface at equal distance from apex and base of the ventricle. The excitation approaches to epicardial ventricular surface at these points, and then it spreads all over the surface. Such pattern of epicardial activation is also shown in mammals where it is related to conduction system functioning. Thus, the precursor of conduction system seems to exist in the frog ventricle, too.

  3. Early-Life Diet Affects Host Microbiota and Later-Life Defenses Against Parasites in Frogs.

    Science.gov (United States)

    Knutie, Sarah A; Shea, Lauren A; Kupselaitis, Marinna; Wilkinson, Christina L; Kohl, Kevin D; Rohr, Jason R

    2017-10-01

    Food resources can affect the health of organisms by altering their symbiotic microbiota and affecting energy reserves for host defenses against parasites. Different diets can vary in their macronutrient content and therefore they might favor certain bacterial communities of the host and affect the development and maintenance of the immune system, such as the inflammatory or antibody responses. Thus, testing the effect of diet, especially for animals with wide diet breadths, on host-associated microbiota and defenses against parasites might be important in determining infection and disease risk. Here, we test whether the early-life diet of Cuban tree frogs (Osteopilus septentrionalis) affects early- and later-life microbiota as well as later-life defenses against skin-penetrating, gut worms (Aplectana hamatospicula). We fed tadpoles two ecologically common diets: a diet of conspecifics or a diet of algae (Arthrospira sp.). We then: (1) characterized the gut microbiota of tadpoles and adults; and (2) challenged adult frogs with parasitic worms and measured host resistance (including the antibody-mediated immune response) and tolerance of infections. Tadpole diet affected bacterial communities in the guts of tadpoles but did not have enduring effects on the bacterial communities of adults. In contrast, tadpole diet had enduring effects on host resistance and tolerance of infections in adult frogs. Frogs that were fed a conspecific-based diet as tadpoles were more resistant to worm penetration compared with frogs that were fed an alga-based diet as tadpoles, but less resistant to worm establishment, which may be related to their suppressed antibody response during worm establishment. Furthermore, frogs that were fed a conspecific-based diet as tadpoles were more tolerant to the effect of parasite abundance on host mass during worm establishment. Overall, our study demonstrates that the diet of Cuban tree frog tadpoles affects the gut microbiota and defenses against

  4. Oregon spotted frog (Rana pretiosa) monitoring in the Oregon Cascades 2012-2016

    Science.gov (United States)

    Adams, Michael J.; Pearl, Christopher A.; Mccreary, Brome; Galvan, Stephanie; Rowe, Jennifer

    2017-01-01

    This dataset contains information from visual encounter surveys conducted between 2012 and 2016 by USGS as part of an ongoing Oregon spotted frog (Rana pretiosa) monitoring effort in the Oregon Cascade Mountain Range. We surveyed 91 sites using a rotating frame design in the Klamath and Deschutes Basins, Oregon, which encompass most of the species' core extant range. Data consist of spotted frog counts aggregated by date, location, and life stage, as well as data on environmental conditions at the time of each survey.

  5. Regulation of 5'-adenosine monophosphate deaminase in the freeze tolerant wood frog, Rana sylvatica

    Directory of Open Access Journals (Sweden)

    Storey Kenneth B

    2008-04-01

    Full Text Available Abstract Background The wood frog, Rana sylvatica, is one of a few vertebrate species that have developed natural freeze tolerance, surviving days or weeks with 65–70% of its total body water frozen in extracellular ice masses. Frozen frogs exhibit no vital signs and their organs must endure multiple stresses, particularly long term anoxia and ischemia. Maintenance of cellular energy supply is critical to viability in the frozen state and in skeletal muscle, AMP deaminase (AMPD plays a key role in stabilizing cellular energetics. The present study investigated AMPD control in wood frog muscle. Results Wood frog AMPD was subject to multiple regulatory controls: binding to subcellular structures, protein phosphorylation, and effects of allosteric effectors, cryoprotectants and temperature. The percentage of bound AMPD activity increased from 20 to 35% with the transition to the frozen state. Bound AMPD showed altered kinetic parameters compared with the free enzyme (S0.5 AMP was reduced, Hill coefficient fell to ~1.0 and the transition to the frozen state led to a 3-fold increase in S0.5 AMP of the bound enzyme. AMPD was a target of protein phosphorylation. Bound AMPD from control frogs proved to be a low phosphate form with a low S0.5 AMP and was phosphorylated in incubations that stimulated PKA, PKC, CaMK, or AMPK. Bound AMPD from frozen frogs was a high phosphate form with a high S0.5 AMP that was reduced under incubation conditions that stimulated protein phosphatases. Frog muscle AMPD was activated by Mg·ATP and Mg·ADP and inhibited by Mg·GTP, KCl, NaCl and NH4Cl. The enzyme product, IMP, uniquely inhibited only the bound (phosphorylated enzyme from muscle of frozen frogs. Activators and inhibitors differentially affected the free versus bound enzyme. S0.5 AMP of bound AMPD was also differentially affected by high versus low assay temperature (25 vs 5°C and by the presence/absence of the natural cryoprotectant (250 mM glucose that

  6. The Japanese tree frog (Hyla japonica), one of the most cold-resistant species of amphibians.

    Science.gov (United States)

    Berman, D I; Meshcheryakova, E N; Bulakhova, N A

    2016-11-01

    The Japanese tree frog, a representative of the Manchurian fauna, is characterized by an outstanding cold resistance among the anuran amphibian species studied so far. Almost 70% of the specimens from the population inhabiting the middle Amur River withstand the cooling down to-30°C; some animals, down to-35°C. This exceeds more than twofold the cold hardiness of the wood frog (Lithobates sylvaticus LeConte, 1825), which has been considered earlier to be the most cold-resistant species. The ability of H. japonica to survive for four months in the frozen state at low temperatures makes this species independent of the temperature overwintering conditions.

  7. Novel relationships among hyloid frogs inferred from 12S and 16S mitochondrial DNA sequences.

    Science.gov (United States)

    Darst, Catherine R; Cannatella, David C

    2004-05-01

    Advanced frogs (Neobatrachia) are usually divided into two taxa, Ranoidea (the firmisternal frogs) and Hyloidea (all other neobatrachians). We investigated phylogenetic relationships among several groups of Hyloidea using 12S and 16S rRNA mitochondrial gene sequences and tested explicit relationships of certain problematic hyloid taxa using a sample of 93 neobatrachians. Parsimony, maximum likelihood, and Bayesian inference methods suggest that both the Ranoidea and Hyloidea are well-supported monophyletic groups. We reject three hypotheses using parametric bootstrap simulation: (1) Dendrobatidae lies within the Ranoidea; (2) The group containing Hylidae, Pseudidae, and Centrolenidae is monophyletic; and (3) Brachycephalus is part of Bufonidae.

  8. Three new species of the microhylid frog genus Choerophryne (Amphibia, Anura, Microhylidae from Papua New Guinea

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    Rainer Günther

    2017-05-01

    Full Text Available We describe three new species of the microhylid frog genus Choerophryne from the mountains and foothills of southern and northeastern Papua New Guinea. All three species lack elongated snouts and all are arboreal calling from elevated perch sites between ~1 and 10 m above the forest floor. Advertisement calls and habitat preferences are described for each species. Descriptions of these three frogs brings the total number of Choerophryne recognized to 34 but numerous additional species undoubtedly remain to be discovered in poorly-surveyed mountainous regions of New Guinea.

  9. A new Gephyromantis (Phylacomantis frog species from the pinnacle karst of Bemaraha, western Madagascar

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    Angelica Crottini

    2011-02-01

    Full Text Available We describe a new mantellid frog of the subfamily Mantellinae from the karstic Bemaraha Plateau, western Madagascar. The new species belongs to the genus Gephyromantis, subgenus Phylacomantis, which previously included G. azzurrae, G. corvus and G. pseudoasper. Gephyromantis atsingy sp. n. has a snout-vent length of 35–43 mm and is a scansorial frog living among the Tsingy de Bemaraha pinnacles and inside the caves present in the area. A morphological analysis and biomolecular comparison revealed the degree of differentiation between these four species of the Phylacomantis subgenus. The new species seems to be endemic to Tsingy de Bemaraha.

  10. Introducing the Forensic Research/Reference on Genetics knowledge base, FROG-kb.

    Science.gov (United States)

    Rajeevan, Haseena; Soundararajan, Usha; Pakstis, Andrew J; Kidd, Kenneth K

    2012-09-01

    Online tools and databases based on multi-allelic short tandem repeat polymorphisms (STRPs) are actively used in forensic teaching, research, and investigations. The Fst value of each CODIS marker tends to be low across the populations of the world and most populations typically have all the common STRP alleles present diminishing the ability of these systems to discriminate ethnicity. Recently, considerable research is being conducted on single nucleotide polymorphisms (SNPs) to be considered for human identification and description. However, online tools and databases that can be used for forensic research and investigation are limited. The back end DBMS (Database Management System) for FROG-kb is Oracle version 10. The front end is implemented with specific code using technologies such as Java, Java Servlet, JSP, JQuery, and GoogleCharts. We present an open access web application, FROG-kb (Forensic Research/Reference on Genetics-knowledge base, http://frog.med.yale.edu), that is useful for teaching and research relevant to forensics and can serve as a tool facilitating forensic practice. The underlying data for FROG-kb are provided by the already extensively used and referenced ALlele FREquency Database, ALFRED (http://alfred.med.yale.edu). In addition to displaying data in an organized manner, computational tools that use the underlying allele frequencies with user-provided data are implemented in FROG-kb. These tools are organized by the different published SNP/marker panels available. This web tool currently has implemented general functions possible for two types of SNP panels, individual identification and ancestry inference, and a prediction function specific to a phenotype informative panel for eye color. The current online version of FROG-kb already provides new and useful functionality. We expect FROG-kb to grow and expand in capabilities and welcome input from the forensic community in identifying datasets and functionalities that will be most helpful

  11. Pathogenic fungus Batrachochytrium dendrobatidis in marbled water frog Telmatobius marmoratus: first record from Lake Titicaca, Bolivia.

    Science.gov (United States)

    Cossel, John; Lindquist, Erik; Craig, Heather; Luthman, Kyle

    2014-11-13

    The pathogenic fungus Batrachochytrium dendrobatidis (Bd) has been associated with amphibian declines worldwide but has not been well-studied among Critically Endangered amphibian species in Bolivia. We sampled free-living marbled water frogs Telmatobius marmoratus (Anura: Leptodactylidae) from Isla del Sol, Bolivia, for Bd using skin swabs and quantitative polymerase chain reactions. We detected Bd on 44% of T. marmoratus sampled. This is the first record of Bd in amphibians from waters associated with Lake Titicaca, Bolivia. These results further confirm the presence of Bd in Bolivia and substantiate the potential threat of this pathogen to the Critically Endangered, sympatric Titicaca water frog T. culeus and other Andean amphibians.

  12. Pharmacological separation of charge movement components in frog skeletal muscle.

    Science.gov (United States)

    Huang, C L

    1982-03-01

    1. Charge movements to small 10 mV steps superimposed upon a wide range of closely spaced depolarizing voltage-clamp pulses were studied in frog skeletal muscles under different pharmacological conditions in hypertonic solutions.2. In control fibres, capacitance was strongly voltage-dependent, especially between potentials of -60 and -20 mV, confirming earlier work. There was a sharp increase in capacitance at around -50 mV. The dependence of non-linear charge on potential was asymmetrical and saturated at around 25 nC/muF.3. The presence of tetracaine abolished the ;hump' in the non-linear transients, which became simple monotonic decays. The dependence of capacitance upon potential was reduced. The maximum available amount of non-linear charge fell to 10 nC/muF.4. The presence of lidocaine abolished both the ;hump' as well as the monotonic part of the non-linear transients. This resulted in capacitance falling with depolarization from -85 mV.5. Comparing the steady-state properties of the non-linear charge under the different pharmacological conditions made it possible to deduce empirically the following components:(i) A lidocaine-resistant component (q(alpha)), which was responsible for the fall in observed capacitance with depolarization from the control voltage.(ii) A component resistant to tetracaine yet abolished by lidocaine (q(beta)). This possesses quasi-exponential kinetics, and a maximum charge of about 20 nC/muF.(iii) A component abolished by both lidocaine and tetracaine (q(gamma)), which possesses a maximum charge of 15 nC/muF. This has complex kinetics, and its steep dependence upon voltage resembles the potential-dependence of the development of tension in skeletal muscle.

  13. Cost-effective conservation of an endangered frog under uncertainty.

    Science.gov (United States)

    Rose, Lucy E; Heard, Geoffrey W; Chee, Yung En; Wintle, Brendan A

    2016-04-01

    How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well-developed tools exist for prioritizing areas for one-time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost-effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost-effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost-effectiveness analysis. This allowed us to discern between cost-effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost-effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost-effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost-effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost

  14. [Ventricular pump function under ectopic excitation of the frog heart].

    Science.gov (United States)

    Kibler, N A; Belogolova, A S; Vaĭkshnoraĭte, M A; Azarov, Ia E; Shmakov, D N

    2008-02-01

    The ventricular pump function under ectopic excitation of the heart was studied in decapitated and pithed adult frogs Rana temporaria (n = 21) at 18-19 degrees C. The intraventricular pressure was recorded with a catheter via ventricular wall. During pacing of the ventricular base and apex, the systolic pressure decreased (6.1 +/- 4.5 mm Hg and 8.9 +/- 5.0 mm Hg, respectively) as compared to the supraventricular rhythm (8.9 +/- 5.0 mm Hg, p < 0.05). The end-diastolic pressure decreased insignificantly both under basal and apical pacing. The systolic rate of pressure rise during dP/dtmax decreased under ventricular pacing, especially during pacing of the ventricular apex, as compared to the supraventricular rhythm (14.4 +/- 6/9 mm Hg/s and 22.1 +/- 11.2 mm Hg/s, respectively, p < 0.003). The isovolumetric relaxation (dP/dtmin) slowed during apical pacing as compared to the supraventricular rhythm (-25.1 +/- 13.6 and -35.6 +/- 18.3 mm Hg/s, respectively, p < 0.03). Ectopic excitation of the ventricular base and apex resulted in increase of the QRS duration (93 +/- 33 ms and 81 +/- 30 ms, respectively) as compared to the supraventricular rhythm (63 +/- 13 ms, p < 0.05). Thus, pacing of different ventricular areas ventricular myocardium with the ventricular pump function being reduced more obviously during the apical pacing compared to the pacing of ventricular base.

  15. A tree of tree frogs around the Black Sea.

    Science.gov (United States)

    Irwin, Darren E

    2016-09-01

    Speciation, the process by which one species evolves into two or more, is a major focus of ongoing debate, particularly regarding the geographic context in which it occurs. Geographic models of speciation tend to fall into discrete categories, typically referred to as allopatric, parapatric and sympatric speciation, according to whether two groups evolve reproductive isolation while geographically isolated, differentiated but connected by gene flow, or completely co-occurring. Yet molecular studies indicate that full development of reproductive isolation can take very long compared with the timescale at which climatic oscillations occur, such that the geographic context of differentiating forms might change often during the long process to full species. Studies of genetic relationships across the ranges of organisms with low-dispersal distances have the potential to reveal these complex histories. In a particularly elegant example in this issue, Dufresnes et al. () use genetic variation and ecological niche modelling to show that a ring of populations of the eastern tree frog (Hyla orientalis) surrounding the Black Sea had a complex history of geographic differentiation. Alternating phases of geographic fragmentation and phases of gene flow between neighbouring populations have produced a pattern of gradual genetic change connecting the western, southern and eastern sides of the ring, with the northwestern and northeastern forms being most differentiated. In the north, a population in Crimea appears to have been produced through mixture of the two extreme forms. The overall genetic relationships are reminiscent of those found in ring species, which have been used as prime demonstrations of the process of speciation. The difference, however, is that the terminal forms appear to have mixed rather than be reproductively isolated, although more research is needed to infer whether there might be some reproductive isolation on the northern side of the ring. © 2016 John

  16. Dry-season retreat and dietary shift of the dart-poison frog Dendrobates tinctorius (Anura: Dendrobatidae

    Directory of Open Access Journals (Sweden)

    Marga Born

    2010-07-01

    Full Text Available Seasonal rainfall affects tropical forest dynamics and behaviorof species that are part of these ecosystems. The positive correlation between amphibian activity patterns and rainfall has been demonstrated repeatedly. Members of Dendrobatidae, a clade of Neotropical dart-poison frogs, are well known for their habitat use and behavior during the rainy season, but their behavior during the dry season has received little attention. We studied habitat use and diet of the dendrobatid frog Dendrobates tinctorius in French Guiana during the rainy and dry seasons. Unlike many other dendrobatid frogs, D. tinctorius does not maintain territories for the entire rainy season. Both sexes colonize recently formed canopy-gaps and stay in these forest patches for only a few weeks. The frogs inthese patches consume a great diversity of prey, consisting of ants, beetles, wasps, insect larvae, and mites. During the dry season, frogs move to retreat sites in mature forest, such as palm bracts and tree holes. The frogs are less active and consume fewer prey items in the dry season, and they consume fewer wasps and insect larvae, but more termites. Ants are the most common prey items during both the wet and dry seasons. We discuss the effects of shifts in seasonal habitat use on the territorial behavior of dendrobatid frogs.

  17. Differentiation of frog fats from vegetable and marine oils by Fourier Transform Infrared Spectroscopy and chemometric analysis

    Directory of Open Access Journals (Sweden)

    A. N. Nina Naquiah

    2015-01-01

    Full Text Available The agro-based production and consumption of frogs coupled with world-wide trading have been increased in the recent years giving rise to the risk of frog fat adulteration in expensive vegetable and marine oils. For the first time, we profiled here frog fats using Fourier Transform Infrared (FTIR Spectroscopy coupled with multivariate principal component analysis (PCA. The comparison of the FTIR spectral absorbance intensities demonstrated linkage of frog fats to other edible fats and oils. Three commercially available marine oils and three vegetables oils were studied with frog fats and clear pattern of clusters with distinctive identifiable features were obtained through PCA modeling. PCA analysis identified 2922.21 cm-1, 2852.88 cm-1, 1745.45 cm-1, 1158.29 cm-1 and 721.51 cm-1 FTIR-frequencies as the most discriminating variables influencing the group separation into different clusters. This fundamental study has clear implications in the identification of frog fat from its marine and vegetable counterparts for the potential detection of frog fat adulteration in various fat and oils.

  18. Phosphoglycerate kinase 1 expression responds to freezing, anoxia, and dehydration stresses in the freeze tolerant wood frog, Rana sylvatica.

    Science.gov (United States)

    Wu, Shaobo; Storey, Janet M; Storey, Kenneth B

    2009-01-01

    Natural freezing survival by wood frogs (Rana sylvatica) involves multiple organ-specific changes in gene expression. Screening of a cDNA library made from brain of frozen frogs revealed freeze-responsive up-regulation of the glycolytic enzyme, phosphoglycerate kinase 1 (PGK1). Northern blots showed an approximately two-fold increase in pgk1 transcripts in brain of frozen frogs whereas PGK1 protein levels rose by three- to five-fold within 4-8 hr of freezing. Freezing also elevated pgk1 transcripts in liver but not in skin. Both transcript and protein levels also rose in response to two of the component stresses of freezing (anoxia and dehydration) with a particularly pronounced (11-fold) increase in PGK1 protein in brain in response to anoxia. Amino acid sequence analysis showed 92.5% identity between wood frog and Xenopus laevis PGK1 and 86-88% identity with the zebrafish, chicken, and human protein. Four unique amino acid substitutions in the wood frog protein could be important in maintaining the functional conformation of the wood frog protein at low body temperatures. Elevated amounts of PGK1, one of the ATP-generating reactions of glycolysis, in wood frog brain during freezing would enhance the glycolytic capacity of the organ and support the maintenance of cellular energetics under the ischemic conditions of the frozen state. 2008 Wiley-Liss, Inc

  19. Relying on known or exploring for new? Movement patterns and reproductive resource use in a tadpole-transporting frog

    Directory of Open Access Journals (Sweden)

    Kristina B. Beck

    2017-08-01

    Full Text Available Animals relying on uncertain, ephemeral and patchy resources have to regularly update their information about profitable sites. For many tropical amphibians, widespread, scattered breeding pools constitute such fluctuating resources. Among tropical amphibians, poison frogs (Dendrobatidae exhibit some of the most complex spatial and parental behaviors—including territoriality and tadpole transport from terrestrial clutches to ephemeral aquatic deposition sites. Recent studies have revealed that poison frogs rely on spatial memory to successfully navigate through their environment. This raises the question of when and how these frogs gain information about the area and suitable reproductive resources. To investigate the spatial patterns of pool use and to reveal potential explorative behavior, we used telemetry to follow males of the territorial dendrobatid frog Allobates femoralis during tadpole transport and subsequent homing. To elicit exploration, we reduced resource availability experimentally by simulating desiccated deposition sites. We found that tadpole transport is strongly directed towards known deposition sites and that frogs take similar direct paths when returning to their home territory. Frogs move faster during tadpole transport than when homing after the deposition, which probably reflects different risks and costs during these two movement phases. We found no evidence for exploration, neither during transport nor homing, and independent of the availability of deposition sites. We suggest that prospecting during tadpole transport is too risky for the transported offspring as well as for the transporting male. Relying on spatial memory of multiple previously discovered pools appears to be the predominant and successful strategy for the exploitation of reproductive resources in A. femoralis. Our study provides for the first time a detailed description of poison frog movement patterns during tadpole transport and corroborates

  20. Medicinal use of secretions (“the frog vaccine” from the kambô frog (Phyllomedusa bicolor by non-indigenous peoples in Rondônia, Brazil

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio Bernarde

    2009-09-01

    Full Text Available Amphibians have pharmaceutically active skin secretions that protect against infections and predation. Some indigenous people in southwestern Amazonia use these secretions from P. bicolor for medicinal purposes. While the use of these secretions by indigenous people is relatively well-known, the use by non-indigenous peoples is very poorly studied. Here we describe the use of the “frog vaccine” by non-indigenous populations in the Brazilian state of Rondônia. Thirty-one people who had received this “vaccine” were interviewed. The use of this vaccine is not typical or habitual in this region, and the person who administers the vaccine must travel from another part of Amazonia. Users of the vaccine come from middle and upper social classes with reasonable levels of education (primary, secondary and university. Approximately half the people vaccinated felt that their health had improved after vaccination and if need be, they would take the vaccination again. Most of the people do not know the frog species from which the secretions are taken. While the people who use this treatment believe that it is good for any infirmity, the medicinal properties, if any, of the “frog vaccine” are under study and are still unknown.

  1. Chilled frogs are hot: hibernation and reproduction of the Endangered mountain yellow-legged frog Rana muscosa

    Science.gov (United States)

    Santana, Frank E.; Swaisgood, Ronald R.; Lemm, Jeffrey M.; Fisher, Robert N.; Clark, Rulon W.

    2015-01-01

    In the face of the sixth great extinction crisis, it is imperative to establish effective breeding protocols for amphibian conservation breeding programs. Captive efforts should not proceed by trial and error, nor should they jump prematurely to assisted reproduction techniques, which can be invasive, difficult, costly, and, at times, counterproductive. Instead, conservation practitioners should first look to nature for guidance, and replicate key conditions found in nature in the captive environment, according to the ecological and behavioral requirements of the species. We tested the effect of a natural hibernation regime on reproductive behaviors and body condition in the Endangered mountain yellow-legged frog Rana muscosa. Hibernation had a clear positive effect on reproductive behavior, manifesting in vocal advertisement signaling, female receptivity, amplexus, and oviposition. These behaviors are critical components of courtship that lead to successful reproduction. Our main finding was that captive R. muscosa require a hibernation period for successful reproduction, as only hibernated females produced eggs and only hibernated males successfully fertilized eggs. Although hibernation also resulted in a reduced body condition, the reduction appeared to be minimal with no associated mortality. The importance of hibernation for reproduction is not surprising, since it is a major component of the conditions that R. muscosa experiences in the wild. Other amphibian conservation breeding programs can also benefit from a scientific approach that tests the effect of natural ecological conditions on reproduction. This will ensure that captive colonies maximize their role in providing genetic reservoirs for assurance and reintroduction efforts.

  2. Frogs in the spotlight: a 16-year survey of native frogs and invasive toads on a floodplain in tropical Australia.

    Science.gov (United States)

    Brown, Gregory P; Shine, Richard

    2016-07-01

    Although widespread declines in anuran populations have attracted considerable concern, the stochastic demographics of these animals make it difficult to detect consistent trends against a background of spatial and temporal variation. To identify long-term trends, we need datasets gathered over long time periods, especially from tropical areas where anuran biodiversity is highest. We conducted road surveys of four anurans in the Australian wet-dry tropics on 4637 nights over a 16-year period. Our surveys spanned the arrival of invasive cane toads (Rhinella marina), allowing us to assess the invader's impact on native anuran populations. Our counts demonstrate abrupt and asynchronous shifts in abundance and species composition from one year to the next, not clearly linked to rainfall patterns. Typically, periods of decline in numbers of a species were limited to 1-2 years and were followed by 1- to 2-year periods of increase. No taxa showed consistent declines over time, although trajectories for some species showed significant perturbations coincident with the arrival of toads. None of the four focal frog species was less common at the end of the study than at the beginning, and three of the species reached peak abundances after toad arrival. Survey counts of cane toads increased rapidly during the initial stage of invasion but have subsequently declined and fluctuated. Distinguishing consistent declines versus stochastic fluctuations in anuran populations requires extensive time-series analysis, coupled with an understanding of the shifts expected under local climatic conditions. This is especially pertinent when assessing impacts of specific perturbations such as invasive species.

  3. Slipping through the cracks: rubber plantation is unsuitable breeding habitat for frogs in Xishuangbanna, China.

    NARCIS (Netherlands)

    Behm, J.E.; Yang, X.; Chen, J.

    2013-01-01

    Conversion of tropical forests into agriculture may present a serious risk to amphibian diversity if amphibians are not able to use agricultural areas as habitat. Recently, in Xishuangbanna Prefecture, Yunnan Province - a hotspot of frog diversity within China - two-thirds of the native tropical

  4. Different Effects of Road Traffic Noise and Frogs' Croaking on Night Sleep

    Science.gov (United States)

    SASAZAWA, Y.; XIN, P.; SUZUKI, S.; KAWADA, T.; KUROIWA, M.; TAMURA, Y.

    2002-02-01

    This study was designed to assess the effects of road traffic noise and frogs' croaking on the objective and subjective quality of sleep in a laboratory. The subjects were seven male students aged 19-21 years. They were exposed to recorded road traffic noise and frogs' croaking, with 49·6 and 49·5 dB(A)LAeq , and 71·2 and 56·1 dB(A) LAmax, respectively. The background noise in the experimental room was 31·0 dB(A) LAeq. The sleep EEG was recorded according to standard methods. The sleep polygraphic parameters examined were the percentage of sleep stage relative to the total sleep time (%S1, %S2, %S(3+4), %SREM, %MT), total sleep time, sleep onset latency, and awakening during sleep in minutes and sleep efficiency. A structured sleep rating questionnaire (OSA), was administered to the subjects after they awakened. The %S2 increased and the %SREM decreased during exposure to road traffic noise. However, no significant effect of exposure to frogs' croaking was observed on any of the polygraphic sleep parameters. The subjective quality of sleep was degraded more by exposure to road traffic noise than that to frogs' croaking.

  5. How to subsidize contributions to public goods: Does the frog jump out of the boiling water?

    NARCIS (Netherlands)

    Offerman, T.; van der Veen, A.

    2009-01-01

    According to popular belief, frogs jump out of the water when the temperature is raised quickly while they are boiled to death when the water is gradually heated. In this paper, we investigate how humans respond to a very slow versus a very steep increase of a subsidy on contributions to a public

  6. Chytrid Fungus, Batrachochytrium dendrobatidis , in Wild Populations of the Lake Titicaca Frog, Telmatobius culeus, in Peru.

    Science.gov (United States)

    Berenguel, Raul A; Elias, Roberto K; Weaver, Thomas J; Reading, Richard P

    2016-10-01

    The Lake Titicaca frog (Telmatobius culeus) is critically endangered, primarily from overexploitation. However, additional threats, such as chytrid fungus ( Batrachochytrium dendrobatidis ), are poorly studied. We found moderate levels of chytrid infection using quantitative PCR. Our results enhance our understanding of chytrid tolerance to high pH and low water temperature.

  7. Disgusting or delicious? Predatory behavior of the hylid frog Phyllodytes luteolus on sympatric ants

    Directory of Open Access Journals (Sweden)

    Mirco Solé

    2017-10-01

    Full Text Available ABSTRACT The phytotelm-dwelling frogs from the genus Phyllodytes Wagler, 1830 have been characterized as specialist frogs regarding their diet strategy which is mainly composed by colonial insects. Herein, we used two species of ants (Camponotus sp. and Gnamptogenys sp. with distinct defensive mechanisms to test the predatory behavior of Phyllodytes luteolus Wied, 1824. The experiment was conducted with frogs inhabiting a patch of 20 bromeliads (Aechmea cf. blanchetiana. Ants were offered randomly to the frogs until we obtained ten observations of predation of each ant species. We observed and recorded the time that P. luteolus needed to keep each ant species inside its mouth before it could ingest it. Predatory behavior was highly distinct. While Camponotus were caught and swallowed within six seconds and without apparent discomfort, individuals of P. luteolus had more difficulty in swallowing Gnamptogenys individuals, the time of manipulation ranging from 57 to 177 seconds. The mean values of time of predation observed in each treatment was highly significant (p<0.001. We conclude that differences found in the time of manipulation are highly correlated with defense mechanisms of each species of ants.

  8. A Novel Vasoactive Proline-Rich Oligopeptide from the Skin Secretion of the Frog Brachycephalus ephippium

    DEFF Research Database (Denmark)

    Arcanjo, Daniel Dias Rufino; Vasconcelos, Andreanne Gomes; Comerma-Steffensen, Simón Gabriel

    2015-01-01

    , PROs decrease blood pressure in animals. In the present study, the isolation and biological characterization of a novel vasoactive BPP isolated from the skin secretion of the frog Brachycephalus ephippium is described. This new PRO, termed BPP-Brachy, has the primary structure WPPPKVSP and the amidated...

  9. Formation of cell masses in the myelencephalon of the clawed frog ...

    African Journals Online (AJOL)

    An important process in the organization of developing nervous system is the clustering of neurons with similar properties to form nuclei. The development of myelencephalon of Xenopus muelleri, a pipid frog that retains a lateral line system throughout life, was studied in Nissl stained serial sections. The results showed that ...

  10. Inherent rhythmcity and interstitial cells of Cajal in a frog vein

    Indian Academy of Sciences (India)

    Interstitial cells of Cajal are responsible for rhythmic contractions of the musculature of the gastrointestinal tract and blood vessels. The existence of these cells and spontaneous rhythmicity were noticed in amphibian vein and the findings are reported in this paper. The postcaval vein was identified in the frog, Rana tigrina ...

  11. Colonization and biology of the frog-feeding mosquito Uranotaeinia macfarlanei in the Ryukyu Archipelago.

    Science.gov (United States)

    Miyagi, Ichiro; Toma, Takako; Tamashiro, Mikako; Higa, Yukiko; Kinjyo, Takako; Takara, Tomio

    2010-03-01

    A colony of Uranotaenia macfarlanei, a frog-feeding mosquito, was established in the laboratory. We report the bionomics of the species, as studied in the laboratory colony and in the field on Ryukyu Island, Japan. These include mating activity, feeding and resting habits, manner of oviposition, and egg, larval, and pupal periods.

  12. Natural history and conservation of the rediscovered Hula painted frog, Latonia nigriventer

    NARCIS (Netherlands)

    Bina Perl, R.G.; Gafny, S.; Malka, Y.; Renan, S.; Woodhams, D.C.; Rollins-Smith, L.; Pask, J.D.; Bletz, M.C.; Geffen, E.; Vences, M.

    2017-01-01

    Dramatic global amphibian declines have recently led to an increased concern for many species of this animal class. The enigmatic Hula painted frog (Latonia nigriventer), the first amphibian to be declared extinct but unexpectedly rediscovered in 2011, has remained one of the rarest and most poorly

  13. Chloramphenicol with fluid and electrolyte therapy cures terminally ill green tree frogs (Litoria caerulea) with chytridiomycosis.

    Science.gov (United States)

    Young, Sam; Speare, Rick; Berger, Lee; Skerratt, Lee F

    2012-06-01

    Terminal changes in frogs infected with the amphibian fungal pathogen Batrachochytrium dendrobatidis (Bd) include epidermal degeneration leading to inhibited epidermal electrolyte transport, systemic electrolyte disturbances, and asystolic cardiac arrest. There are few reports of successful treatment of chytridiomycosis and none that include curing amphibians with severe disease. Three terminally ill green tree frogs (Litoria caerulea) with heavy Bd infections were cured using a combination of continuous shallow immersion in 20 mg/L chloramphenicol solution for 14 days, parenteral isotonic electrolyte fluid therapy for 6 days, and increased ambient temperature to 28 degrees C for 14 days. All terminally ill frogs recovered rapidly to normal activity levels and appetite within 5 days of commencing treatment. In contrast, five untreated terminally ill L. caerulea with heavy Bd infections died within 24-48 hr of becoming moribund. Subclinical infections in 15 experimentally infected L. caerulea were cured within 28 days by continuous shallow immersion in 20 mg/L chloramphenicol solution without adverse effects. This is the first known report of a clinical treatment protocol for curing terminally ill Bd-infected frogs.

  14. Description of a new moss frog from the south-western Cape (Anura ...

    African Journals Online (AJOL)

    A new species of moss frog, genus Arthroleptella, is described from the Kleinrivier mountains of the south-western Cape. It is morphologically indistinguishable from the other three species in the area. The four Cape species are allopatric, each has a unique male advertisement call, and preliminary molecular data shows ...

  15. Dissecting the frog inner ear with Gaussian noise .2. Temperature dependence of inner ear function

    NARCIS (Netherlands)

    vanDijk, P; Wit, HP; Segenhout, JM

    1997-01-01

    The temperature dependence of the response of single primary auditory nerve fibers (n = 31) was investigated in the European edible frog, Rana esculenta (seven ears). Nerve fiber responses were analyzed with Wiener kernel analysis and polynomial correlation. The responses were described with a

  16. A taxonomic revision of the Neotropical poison frog genus Ranitomeya (Amphibia: Dendrobatidae)

    NARCIS (Netherlands)

    Brown, J.L.; Twomey, E.; Amézquita, A.; Souza, M.B.; Caldwell, J.P.; Lötters, S.; May, R.; Melo-Sampaio, P.R.; Mejía-Vargas, D.; Perez-Peña, P.; Pepper, M.; Poelman, E.H.; Sanchez-Rodriguez, M.; Summers, K.

    2011-01-01

    The Neotropical poison frog genus Ranitomeya is revised, resulting in one new genus, one new species, five synonymies and one species classified as nomen dubium. We present an expanded molecular phylogeny that contains 235 terminals, 104 of which are new to this study. Notable additions to this

  17. Microsatellite variation and population structure of a recovering tree frog (Hyla arborea L.) metapopulation

    NARCIS (Netherlands)

    Arens, P.F.P.; Bugter, R.J.F.; Westende, van 't W.P.C.; Zollinger, R.; Stronks, J.; Vos, C.C.; Smulders, M.J.M.

    2006-01-01

    Numbers and sizes of populations of the European tree frog in The Netherlands have dramatically decreased in the second half of the last century due to extensive habitat destruction and fragmentation. We have studied the genetic structure of a slowly recovering meta-population. Strong genetic

  18. Effects of dopamine agonists on calling behavior in the green tree frog, Hyla cinerea.

    Science.gov (United States)

    Creighton, Anna; Satterfield, Dara; Chu, Joanne

    2013-05-27

    Dopamine (DA) is an important neurotransmitter involved in social behaviors, such as courtship and pair-bonding. In the green tree frog (Hyla cinerea), calling behavior is the primary social behavior used for mate attraction, and is critical for the reproductive success of the species. Our study examined how DA influences advertisement calling behavior of the green tree frog. In a field environment, calling males were treated with either a DA receptor-specific agonist (SKF-38393 or quinpirole), a non-specific DA agonist (apomorphine), or a control Ringer's solution, and vocalizations were recorded after a 20 min post-injection period. Behavioral analyses focused on if and when the frogs called (call latency), and the number of calls produced during post-injection recordings (call rate). There were significant differences in all measurements that varied with treatment and/or dose. The results demonstrate that activation of D2-like receptors has an inhibitory effect on vocalization in the green tree frog, while the D1-like and non-specific DA agonists do not affect calling behavior. These findings coincide with behavioral data from other taxa, and support the function of D2-like receptors in the inhibition of certain social behaviors. Overall, the results suggest conservation for DA in social behaviors across vertebrates. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Foothill yellow-legged frog (Rana boylii) oviposition site choice at multiple spatial scales

    Science.gov (United States)

    Amy J. Lind; Hartwell H. Welsh; Clara A. Wheeler

    2016-01-01

    Studies of resource selection at multiple scales are critical to understanding ecological and evolutionary attributes of a species. We analyzed relative abundance, habitat use, and oviposition site selection of Foothill Yellow-Legged Frogs (Rana boylii) at 11 localities across two geographic regions in California (northern Coast Range and Sierra...

  20. Generation of the Dimensional Embryology Application (App) for Visualization of Early Chick and Frog Embryonic Development

    Science.gov (United States)

    Webb, Rebecca L.; Bilitski, James; Zerbee, Alyssa; Symans, Alexandra; Chop, Alexandra; Seitz, Brianne; Tran, Cindy

    2015-01-01

    The study of embryonic development of multiple organisms, including model organisms such as frogs and chicks, is included in many undergraduate biology programs, as well as in a variety of graduate programs. As our knowledge of biological systems increases and the amount of material to be taught expands, the time spent instructing students about…

  1. Design and Dynamic Model of a Frog-inspired Swimming Robot Powered by Pneumatic Muscles

    Science.gov (United States)

    Fan, Ji-Zhuang; Zhang, Wei; Kong, Peng-Cheng; Cai, He-Gao; Liu, Gang-Feng

    2017-09-01

    Pneumatic muscles with similar characteristics to biological muscles have been widely used in robots, and thus are promising drivers for frog inspired robots. However, the application and nonlinearity of the pneumatic system limit the advance. On the basis of the swimming mechanism of the frog, a frog-inspired robot based on pneumatic muscles is developed. To realize the independent tasks by the robot, a pneumatic system with internal chambers, micro air pump, and valves is implemented. The micro pump is used to maintain the pressure difference between the source and exhaust chambers. The pneumatic muscles are controlled by high-speed switch valves which can reduce the robot cost, volume, and mass. A dynamic model of the pneumatic system is established for the simulation to estimate the system, including the chamber, muscle, and pneumatic circuit models. The robot design is verified by the robot swimming experiments and the dynamic model is verified through the experiments and simulations of the pneumatic system. The simulation results are compared to analyze the functions of the source pressure, internal volume of the muscle, and circuit flow rate which is proved the main factor that limits the response of muscle pressure. The proposed research provides the application of the pneumatic muscles in the frog inspired robot and the pneumatic model to study muscle controller.

  2. Patterns of reproduction and habitat use in an assemblage of Neotropical hylid frogs.

    Science.gov (United States)

    Donnelly, Maureen A; Guyer, Craig

    1994-08-01

    We censused pond-breeding hylid frogs in northeastern Costa Rica weekly for 15 months to deseribe patterns of reproduction, habitat use, and to establish baseline data on relative abundance for members of the assemblage. Reproduction in the Costa Rican assemblage was seasonal and occurred only during wet months. Some species called, but none reproduced, during the dry season. Three species (Agalychnis callidryas, Hyla ebraccata, and Scinax elaeochroa) accounted for more than 75% of the observations made during the study. The species overlapped broadly in time and space, but differed in substrate use and phenology. Two species of leaf-breeding frogs (A. callidryas and A. saltator) used perches that were significantly higher than those used by the other species. Some phenological differences were associated with different mating strategies. Explosive breeders (Scinax elaeochroa and Smilisca baudinii) were most common early in the wet seasons. Prolonged breeders (A. callidryas and H. ebraccata) were the most persistent members of this assemblage. Predation affects early and late life history stages of these hylids. Predation on arboreal egg masses by two snake species was observed. Ctenid spiders preyed on recently metamorphosed frogs and small adults. Our weekly samples were pooled into 21-day periods so that we could compare our results with those obtained for two communities of breeding anurans from South America. The patterns observed in the Costa Rican assemblage differed from those reported for South American pond-breeding frogs, but in all three assemblages reproduction was associated with wet periods.

  3. BIOMETRIC STUDY TO RANA RIDIBUNDA FROG SPECIES NEARNESS TO TIMISOARA LOCALITY

    Directory of Open Access Journals (Sweden)

    M. BURA

    2007-10-01

    Full Text Available Speciality literature provides little informations regarding Rana ridibunda frogbiometry. For supply this gap we studied the size and weight of 54 frogs sampled fromnearby Timişoara area ponds.The mean body lenght was 8,08 ± 0,54 cm for the females and respectively 6,17 ± 0,45cm for the males. Before evisceration on a par females weighted 62,28 ± 12,87 g andthe males 22,46 ± 5,3 g whereas after this action the carcase weighted 43,89 ± 8,91 gin the case of females and respectively 18,45 ± 4,42 g in the case of male lake frog. Themean leg lenght measured 12,59 ± 0,68 cm for female frogs and 9,78 ± 0,66 cm in thecase of male frogs. The hind stylopodium was estimated on a par as 13,23 ± 2,57 g forfemales and 5,33 ± 1,26 g for the males.

  4. The impact of fish and drought on frog breeding in temporary waters ...

    African Journals Online (AJOL)

    The breeding of frogs in four ponds near Harare, Zimbabwe, was investigated during a wet rainy season (2000/01) and a dry one (2001/02). During 2000/01 eight and nine species bred in two ponds in abandoned gravel pits that never contained fish, but only four species bred in these in 2001/02 and the relative abundance ...

  5. Investigation of longitudinal profile of rigid frogs on reinforced concrete sleepers

    Directory of Open Access Journals (Sweden)

    A.M. Orlovs’kyi

    2012-08-01

    Full Text Available In the paper the effect of longitudinal profile of rigid frogs of type R65 mark 1/11 on reinforced concrete sleepers on the interaction in the ‘wheel-rail’ system in the zone of rolling surface irregularities is investigated.

  6. Receptor-mediated endocytosis of lysozyme in renal proximal tubules of the frog Rana temporaria

    Directory of Open Access Journals (Sweden)

    E.V. Seliverstova

    2015-04-01

    Full Text Available The mechanism of protein reabsorption in the kidney of lower vertebrates remains insufficiently investigated in spite of raising interest to the amphibian and fish kidneys as a useful model for physiological and pathophysiological examinations. In the present study, we examined the renal tubular uptake and the internalization rote of lysozyme after its intravenous injection in the wintering frog Rana temporaria using immunohisto- and immunocytochemistry and specific markers for some endocytic compartments. The distinct expression of megalin and cubilin in the proximal tubule cells of lysozyme-injected frogs was revealed whereas kidney tissue of control animals showed no positive immunoreactivity. Lysozyme was detected in the apical endocytic compartment of the tubular cells and colocalized with clathrin 10 min after injection. After 20 min, lysozyme was located in the subapical compartment negative to clathrin (endosomes, and intracellular trafficking of lysozyme was coincided with the distribution of megalin and cubilin. However, internalized protein was retained in the endosomes and did not reach lysosomes within 30 min after treatment that may indicate the inhibition of intracellular trafficking in hibernating frogs. For the first time, we provided the evidence that lysozyme is filtered through the glomeruli and absorbed by receptor-mediated clathrin-dependent endocytosis in the frog proximal tubule cells. Thus, the protein uptake in the amphibian mesonephros is mediated by megalin and cubilin that confirms a critical role of endocytic receptors in the renal reabsorption of proteins in amphibians as in mammals.

  7. Cryptic species of sharp-nosed reed frogs in the Hyperolius nasutus ...

    African Journals Online (AJOL)

    The sharp-nosed reed frog is widespread in Africa. Although currently recognized as one species, suggestions have been made that more than one species might exist. We analysed 237 calls of 69 males from 19 localities in the western to southern parts of Africa. Calls fall into three groups, which we recognize as cryptic ...

  8. COMPARATIVE ACTIVITY OF CECROPIN A AND POLYMYXIN B AGAINST FROG BACTERIAL PATHOGENS

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    Ermin Schadich

    2013-03-01

    Full Text Available The antimicrobial activity of two antimicrobial peptides, cecropin A and polymyxin B against different bacterial pathogens associated with bacterial dermatosepticemia, a fatal bacterial infectious disease of frogs was investigated. The peptides were tested in serial of concentrations (100-0.19 µg/ml for growth inhibition of seven pathogens: Aeromonas hydrophila, Chryseobacterium meningosepticum, Citrobacter freundii, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis and Serratia liquefaciens. Their antimicrobial activity was compared with that of two antimicrobial peptides from frog skin, magainin 2 and aurein 2.1. Both cecropin A and polymyxin B, completely inhibited the growth of three pathogens: C. freundii, K. pneumoniae and P. aeruginosa at a concentration some sixteen times less than two skin peptides. Furthermore, cecropin A inhibited the growth of three pathogens resistant to the two skin peptides, A. hydrophila, C. meningosepticum and P. mirabilis. Polymyxin B also inhibited the growth of three pathogens resistant to the skin peptides, A. hydrophila, C. meningosepticum and S. liquefaciens. Cecropin A and polymyxin B have marked antibacterial activity against different frog bacterial pathogens indicating potential for therapeutic measures.Keywords: frogs, antimicrobial, bacteria, cecropin, polymyxin, resistance

  9. Effects of Endocrine Disruptors Ethinylestradiol and Procloraz on the vocal system of the frog Xenopus tropicalis

    DEFF Research Database (Denmark)

    Brande-Lavridsen, Nanna; Nørum, Ulrik; Korsgaard, Bodil

    2009-01-01

    for studying the effects of endocrine disruptors on sexual differentiation. We exposed tadpoles and metamorphs of the species Xenopus tropicalis to the synthetic estrogen ethinylestradiol and the fungicide prochloraz. Prochloraz masculinized the larynx of female frogs while ethinylestradiol had no effect...

  10. Space use of Amazonian poison frogs: Testing the reproductive resource defense hypothesis

    NARCIS (Netherlands)

    Poelman, E.H.; Dicke, M.

    2008-01-01

    In most Anuran species, space use includes a lek mating system with defense of a calling site for only a short time period during an individual's lifespan. In contrast, territoriality over a longer time period by one or both of the sexes has been reported in all studied dendrobatid frogs. In most

  11. Site fidelity of the declining amphibian Rana sierrae (Sierra Nevada yellow-legged frog)

    Science.gov (United States)

    Kathleen Matthews; Haiganoush Preisler

    2010-01-01

    From 1997 to 2006, we used mark–recapture models to estimate the site fidelity of 1250 Sierra Nevada yellow-legged frogs (Rana sierrae) in Kings Canyon National Park, California, USA, during their three main activity periods of overwintering, breeding, and feeding. To quantify site fidelity, the tendency to return to and reuse previously occupied...

  12. On Semiotics and Jumping Frogs: The Role of Gesture in the Teaching of Subtraction

    Science.gov (United States)

    Farrugia, Marie Therese

    2017-01-01

    In this article, I describe a research/teaching experience I undertook with a class of 5-year-old children in Malta. The topic was subtraction on the number line. I interpret the teaching/learning process through a semiotic perspective. In particular, I highlight the role played by the gesture of forming "frog jumps" on the number line.…

  13. Biomimetic agent based modelling using male Frog calling behaviour as a case study

    DEFF Research Database (Denmark)

    Jørgensen, Søren V.; Demazeau, Yves; Christensen-Dalsgaard, Jakob

    2014-01-01

    A new agent-based modelling tool has been developed to allow the modelling of populations of individuals whose interactions are characterised by tightly timed dynamics. The tool was developed to model male frog calling dynamics, to facilitate research into what local rules may be employed by indi...

  14. Effects of forest fragmentation and habitat degradation on West African leaf-litter frogs

    NARCIS (Netherlands)

    Hillers, A.; Veith, M.; Rödel, M.-O.

    2008-01-01

    Habitat degradation alters the dynamics and composition of anuran assemblages in tropical forests. The effects of forest fragmentation on the composition of anuran assemblages are so far poorly known. We studied the joint influence of forest fragmentation and degradation on leaf-litter frogs. We

  15. Frequency-dependent effects of the pyrethroid insecticide decamethrin in frog myelinated nerve fibres

    NARCIS (Netherlands)

    Vijverberg, H.P.M.; Bercken, J. van den

    1979-01-01

    The pyrethroid insectide decamethrin (10−6M) caused a frequency-dependent depression of the action potential in frog myelinated nerve fibres which was associated with a progressive membrane depolarisation brought about by summation of depolarising after-potentials. Voltage clamp experiments with

  16. Complete Genome Sequence of the Frog Pathogen Mycobacterium ulcerans Ecovar Liflandii

    NARCIS (Netherlands)

    Tobias, Nicholas J.; Doig, Kenneth D.; Medema, Marnix H.; Chen, Honglei; Haring, Volker; Moore, Robert; Seemann, Torsten; Stinear, Timothy P.

    In 2004, a previously undiscovered mycobacterium resembling Mycobacterium ulcerans (the agent of Buruli ulcer) was reported in an outbreak of a lethal mycobacteriosis in a laboratory colony of the African clawed frog Xenopus tropicalis. This mycobacterium makes mycolactone and is one of several

  17. Schellackia (Apicomplexa: Eimeriidae of the brazilian tree-frog, Phrynohyas venulosa (Amphibia: Anura from Amazonian Brazil

    Directory of Open Access Journals (Sweden)

    I. Paperna

    1995-10-01

    Full Text Available Endogenous stages of a Schellackia species are described in histological sections of the intestine of the tree-frog, Phrynohyas venulosa, from North Brazil. Most oocysts sporulate within the epithelial cells of the gut, but a few were detected in the lamina propria.

  18. A molecular phylogenetic analysis of the neotropical dart-poison frog genus Phyllobates (Amphibia: Dendrobatidae)

    Science.gov (United States)

    Widmer, A.; Lötters, S.; Jungfer, K.-H.

    A phylogenetic analysis of the Neotropical dart-poison frogs, genus Phyllobates, was performed based on mitochondrial cytochrome b sequences. Members of Phyllobates from South and Central America were found to form each an evolutionary lineage. Among the South American lineage, species with uniform dorsal coloration as adults form a derived monophyletic clade.

  19. Going back to rovuma: the frog fauna of a coastal Dry forest, and a ...

    African Journals Online (AJOL)

    A dendrogram of occurrence data investigating faunal relationships between provinces illustrates Cabo Delgado is closest to Nampula in the number of shared species, reflecting the distribution of East African coastal dry forest frog fauna. Keywords: Amphibia, faunistic study, taxonomy, live colouration, species list ...

  20. No Flower Shall Wither; or, Horticulture in the Kingdom of the Frogs. The Cutting Edge

    Science.gov (United States)

    Clabaugh, Gary K.

    2004-01-01

    Dedicated educators, struggling with the mandates of "No Child Left Behind" will immediately identify with the hero of this allegory. Horace is a small frog, who has a passion for gardening, and watching flowers bloom. As soon as he comes of age, Horace decides to pursue his great love of nurturing tender blooming things. He studies, diligently,…

  1. A stem batrachian from the Early Permian of Texas and the origin of frogs and salamanders.

    Science.gov (United States)

    Anderson, Jason S; Reisz, Robert R; Scott, Diane; Fröbisch, Nadia B; Sumida, Stuart S

    2008-05-22

    The origin of extant amphibians (Lissamphibia: frogs, salamanders and caecilians) is one of the most controversial questions in vertebrate evolution, owing to large morphological and temporal gaps in the fossil record. Current discussions focus on three competing hypotheses: a monophyletic origin within either Temnospondyli or Lepospondyli, or a polyphyletic origin with frogs and salamanders arising among temnospondyls and caecilians among the lepospondyls. Recent molecular analyses are also controversial, with estimations for the batrachian (frog-salamander) divergence significantly older than the palaeontological evidence supports. Here we report the discovery of an amphibamid temnospondyl from the Early Permian of Texas that bridges the gap between other Palaeozoic amphibians and the earliest known salientians and caudatans from the Mesozoic. The presence of a mosaic of salientian and caudatan characters in this small fossil makes it a key taxon close to the batrachian (frog and salamander) divergence. Phylogenetic analysis suggests that the batrachian divergence occurred in the Middle Permian, rather than the late Carboniferous as recently estimated using molecular clocks, but the divergence with caecilians corresponds to the deep split between temnospondyls and lepospondyls, which is congruent with the molecular estimates.

  2. Investigating the distributional limits of the coastal tailed frog (Ascaphus truei) near its southern range terminus

    Science.gov (United States)

    Robert B. Douglas; David W. Ulrich; Christopher A. Morris; Matthew O. Goldsworthy

    2017-01-01

    Documenting species distribution patterns and habitat associations is a necessary prerequisite for developing conservation measures, prioritizing areas for habitat restoration, and establishing baseline conditions for long-term monitoring programs. The coastal tailed frog (Ascaphus truei) ranges from coastal British Columbia to...

  3. Genetic population differentiation and connectivity among fragmented Moor frog (Rana arvalis) populations in The Netherlands

    NARCIS (Netherlands)

    Arens, P.F.P.; Sluis, van der T.; Westende, van 't W.P.C.; Vosman, B.; Vos, C.C.; Smulders, M.J.M.

    2007-01-01

    We studied the effects of landscape structure, habitat loss and fragmentation on genetic differentiation of Moor frog populations in two landscapes in The Netherlands (Drenthe and Noord-Brabant). Microsatellite data of eight loci showed small to moderate genetic differentiation among populations in

  4. Genetic similarity as a measure for connectivity between fragmented populations of the moor frog (Rana arvalis)

    NARCIS (Netherlands)

    Vos, C.C.; Antonisse-de Jong, A.G.; Goedhart, P.W.; Smulders, M.J.M.

    2001-01-01

    Genetic differentiation among populations of the moor frog (Rana arvalis) was tested on a spatial scale where some dispersal between populations is expected to occur, in a landscape in The Netherlands that has become fragmented fairly recently, in the 1930s. Five microsatellite loci were used, with

  5. Tolerance of Frogs among High School Students: Influences of Disgust and Culture

    Science.gov (United States)

    Prokop, Pavol; Medina-Jerez, William; Coleman, Joy; Fancovicová, Jana; Özel, Murat; Fedor, Peter

    2016-01-01

    Amphibians play an important role in the functioning of ecosystems and some of them inhabit human gardens where they can successfully reproduce. The decline of amphibian diversity worldwide suggests that people may play a crucial role in their survival. We conducted a cross-cultural study on high school students' tolerance of frogs in Chile,…

  6. Prevalence of Spirometra mansoni in dogs, cats, and frogs and its medical relevance in Guangzhou, China

    Directory of Open Access Journals (Sweden)

    Qing Hong

    2016-12-01

    Conclusions: A high sparganum infection rate was observed in the wild frogs sold in agricultural product markets in Guangzhou. The infection was also serious in cats and dogs in Guangdong Province. With lifestyles and eating habits resulting in sparganum infection, it is necessary to focus on market management and community education in order to prevent the transmission of this disease in Guangzhou.

  7. Neglecting the call of the wild: Captive frogs like the sound of their own voice.

    Directory of Open Access Journals (Sweden)

    Luiza Figueiredo Passos

    Full Text Available Acoustic communication is highly influential in the expression of social behavior by anuran amphibians, transmitting information about the individual's physical condition and motivation. We studied the phonotactic (approach movements responses of wild and captive male golden mantella frogs to conspecific wild and captive playback calls to determine the impact of captivity on social behaviour mediated by vocalisations. Calls were recorded from one wild and two captive populations. Phonotaxis experiments were then conducted by attracting M. aurantiaca males across a PVC grid on the forest floor or enclosure floor to a speaker. For each playback, the following parameters were recorded to define the accuracy of phonotaxis: (1 number of jumps; (2 jump angles; (3 jump distances; (4 path straightness. During this experiment we observed that wild frogs had a similar behavioural (phonotaxis response to calls independent of their source while frogs from Chester Zoo had a significantly stronger response to calls of other conspecifics held separately at Chester Zoo. The lack of appropriate phonotaxis response by captive bred frogs to the calls of wild conspecifics could have serious negative conservation implications, if the captive bred individuals were released back to the wild.

  8. Contemporary "Hoisan-wa" Language Maintenance in Northern California: Evidence from Fourteen Frog Story Narratives

    Science.gov (United States)

    Leung, Genevieve

    2012-01-01

    This article explores uninvestigated issues in Cantonese and "Hoisan-wa" language maintenance from an ethnic Chinese diaspora point of view. Data come from a larger study looking at Frog Story narratives from 140 Cantonese-English bilingual children in California. Fourteen of these children were found to display uniquely…

  9. Distortion product otoacoustic emissions provide clues to hearing mechanisms in the frog

    Science.gov (United States)

    Vassilakis, Pantelis; Narins, Peter M.

    2003-10-01

    Cubic distortion product otoacoustic emissions (DPOAEs) were recorded from 10 Rana pipiens and 10 Rana catesbeiana, 5 males and 5 females each. The I/O curves obtained from the amphibian papilla (AP) of both species are very similar to the respective mammalian curves, indicating that, like in the mammalian cochlea, there may be an amplification process active in the frog AP. The DPOAE level dependence on primary levels is also similar to the mammalian case, suggesting a mechanical structure in the frog inner ear may be functioning analogously to the mammalian basilar membrane. DPOAE audiograms were obtained for primary frequencies spanning the animals hearing range and levels determined by the previous experiments. R. catesbeiana produce stronger emissions than R. pipiens and, consistent with previously reported sexual dimorphism in the mammalian and anuran auditory systems, females from both species produce stronger emissions than males. Additionally, the 2f1-f2 DPOAE is generated primarily at the DPOAE frequency place, while the 2f2-f1 DPOAE is generated primarily at a frequency place between the primaries. This difference in mammalian and frog DPOAEs may be linked to an anatomical difference that results in the acoustic energy following opposite paths through the mammalian and frog inner ears. [Work supported by NIH Grant No. DC-00222 to Peter M. Narins.] a)Currently at De Paul Univ., School of Music, Chicago, IL 60614.

  10. Neglecting the call of the wild: Captive frogs like the sound of their own voice

    Science.gov (United States)

    Passos, Luiza Figueiredo; Garcia, Gerardo

    2017-01-01

    Acoustic communication is highly influential in the expression of social behavior by anuran amphibians, transmitting information about the individual’s physical condition and motivation. We studied the phonotactic (approach movements) responses of wild and captive male golden mantella frogs to conspecific wild and captive playback calls to determine the impact of captivity on social behaviour mediated by vocalisations. Calls were recorded from one wild and two captive populations. Phonotaxis experiments were then conducted by attracting M. aurantiaca males across a PVC grid on the forest floor or enclosure floor to a speaker. For each playback, the following parameters were recorded to define the accuracy of phonotaxis: (1) number of jumps; (2) jump angles; (3) jump distances; (4) path straightness. During this experiment we observed that wild frogs had a similar behavioural (phonotaxis) response to calls independent of their source while frogs from Chester Zoo had a significantly stronger response to calls of other conspecifics held separately at Chester Zoo. The lack of appropriate phonotaxis response by captive bred frogs to the calls of wild conspecifics could have serious negative conservation implications, if the captive bred individuals were released back to the wild. PMID:28732034

  11. Urinary corticosterone metabolite responses to capture and handling in two closely related species of free-living Fijian frogs.

    Science.gov (United States)

    Narayan, Edward J; Cockrem, John F; Hero, Jean-Marc

    2012-05-15

    Studies of baseline (unstressed) and short-term corticosterone stress responses in free-living amphibians can provide crucial information on the physiological responses of different populations to environmental change. In this study, we compared baseline and urinary corticosterone metabolite responses of free-living adult males and females of two closely related Fijian frogs of the Platymantis genus (Family: Ceratobatrachidae). Fijian ground frogs (Platymantis vitiana) live on the ground while Fijian tree frogs (Platymantis vitiensis) are arboreal. We captured free-living frogs and applied our moderate stress protocol (5 min handling during urine sampling at hourly intervals), with urinary corticosterone metabolite concentrations measured by enzyme-immunoassay. Mean urinary corticosterone metabolite concentrations in male and female Fijian ground frogs increased from 0 to 2 h and continued to increase to peak concentrations 5-6 h after capture. Mean baseline corticosterone concentration was significantly different between sexes (higher in males than females) only for Fijian ground frogs. There was no significant difference between sexes in the integrated corticosterone responses for both species. Mean baseline and urinary corticosterone metabolite responses of Fijian tree frogs were lower than those of Fijian ground frogs. Corticosterone levels increased for 4-5 h in both species and began to decrease again 7 h after initial capture. Corticosterone responses were consistently higher for Fijian ground frogs than Fijian tree frogs. Individuals in both species showed markedly variable corticosterone responses over the 8h duration of the stressor, with some individuals showing low stress responses and others showing high stress responses. The magnitude of the corrected integrated response of the ground frogs was almost twice that of the tree frogs. These differences in baseline and short-term corticosterone stress responses between these two species could be a

  12. Sticking like sticky tape: tree frogs use friction forces to enhance attachment on overhanging surfaces.

    Science.gov (United States)

    Endlein, Thomas; Ji, Aihong; Samuel, Diana; Yao, Ning; Wang, Zhongyuan; Barnes, W Jon P; Federle, Walter; Kappl, Michael; Dai, Zhendong

    2013-03-06

    To live and clamber about in an arboreal habitat, tree frogs have evolved adhesive pads on their toes. In addition, they often have long and slender legs to facilitate not only long jumps, but also to bridge gaps between leaves when climbing. Both adhesive pads and long limbs are used in conjunction, as we will show in this study. Previous research has shown that tree frogs change from a crouched posture (where the limbs are close to the body) to a sprawled posture with extended limbs when clinging on to steeper inclines such as vertical or overhanging slopes. We investigated this change in posture in White's tree frogs (Litoria caerulea) by challenging the frogs to cling onto a tiltable platform. The platform consisted of an array of 24 three-dimensional force transducers, which allowed us to measure the ground reaction forces of the frogs during a tilt. Starting from a crouched resting position, the normal forces on the forelimbs changed sign and became increasingly negative with increasing slope angle of the platform. At about 106° ± 12°, tilt of the platform the frogs reacted by extending one or two of their limbs outwards. At a steeper angle (131° ± 11°), the frogs spread out all their limbs sideways, with the hindlimbs stretched out to their maximum reach. Although the extension was strongest in the lateral direction, limbs were significantly extended in the fore-aft direction as well. With the extension of the limbs, the lateral forces increased relative to the normal forces. The large contribution of the in-plane forces helped to keep the angle between the force vector and the platform small. The Kendall theory for the peeling of adhesive tape predicts that smaller peel angles lead to higher attachment forces. We compare our data with the predictions of the Kendall model and discuss possible implications of the sliding of the pads on the surface. The forces were indeed much larger for smaller angles and thus can be explained by peeling theory.

  13. Effects of CFT Legumine (5% Rotenone) on tadpole survival and metamorphosis of Chiricahua leopard frogs Lithobates chiricahuensis, Northern leopard frogs L. pipiens, and American bullfrogs L. catesbeianus

    Science.gov (United States)

    Alvarez, Guillermo; Caldwell, Colleen A.; Kruse, Carter G.

    2017-01-01

    Amphibians may experience collateral effects if exposed to CFT Legumine (5% rotenone), a piscicide that is used to remove invasive fish. A series of 48-h static toxicity tests assessed the acute effects of CFT Legumine on multi-aged tadpoles of the federally listed Chiricahua leopard frog Lithobates chiricahuensis, the widespread northern leopard frog L. pipiens, and the increasingly invasive American bullfrog L. catesbeianus. At the earliest Gosner stages (GS 21–25), Chiricahua leopard frogs were more sensitive to CFT Legumine (median lethal concentration [LC50] = 0.41–0.58 mg/L) than American bullfrogs (LC50 = 0.63–0.69 mg/L) and northern leopard frogs (LC50 = 0.91 and 1.17 mg/L). As tadpoles developed (i.e., increase in GS), their sensitivity to rotenone decreased. In a separate series of 48-h static nonrenewal toxicity tests, tadpoles (GS 21–25 and GS 31–36) of all three species were exposed to piscicidal concentrations of CFT Legumine (0.5, 1.0, and 2.0 mg/L) to assess postexposure effects on metamorphosis. In survivors of all three species at both life stages, the time to tail resorption was nearly doubled in comparison with that of controls. For example, mid-age (GS 31–36) Chiricahua leopard frog tadpoles required 210.7 h to complete tail resorption, whereas controls required 108.5 h. However, because tail resorption is a relatively short period in metamorphosis, the total duration of development (days from posthatch to complete metamorphosis) and the final weight did not differ in either age-group surviving nominal concentrations of 0.5-, 1.0-, and 2.0-mg/L CFT Legumine relative to controls. This research demonstrates that the CFT Legumine concentrations commonly used in field applications to remove unwanted fish could result in considerable mortality of the earliest stages of Lithobates species. In addition to acute lethality, piscicide treatments may result in delayed tail resorption, which places the tadpoles at risk by increasing

  14. The Breccia of Frog Lakes: Record of Mafic Arc Magmatism in the Mesozoic Sierra Nevada, California

    Science.gov (United States)

    Douglas, S.; Riggs, N.; Barth, A. P.; Economos, R. C.

    2011-12-01

    The evolution of the Mesozoic western margin of North America in California is characterized by a change in tectonic regimes. After the emplacement of the Golconda thrust during the Sonoma orogeny in early Triassic time, the passive western margin changed to a convergent margin with subducting oceanic crust. Onset of arc magmatism is recorded by the volcanic section of Saddlebag Lake pendant in the east-central Sierra Nevada and includes welded tuffs, mafic flows, and volcanic breccias. The welded tuffs and mafic breccias provide insight into the diversity of volcanic processes during early evolution of the Sierran arc. The Mesozoic volcanic section of the Saddlebag Lake pendant (SLP) overlies foreland basin sediments derived from the eroding Golconda allochthon. The initial volcanic unit, the tuff of Black Mountain, is overlain by the conglomerate of Cooney Lake, which contains continental-derived sediment similar to the Candelaria Fm, and no volcanic clasts. Stratigraphically above the conglomerate is the 224 Ma tuff of Saddlebag Lake, which underlies the breccia of Frog Lakes. The breccia of Frog Lakes thus represents the earliest stratigraphic record of mafic volcanism in the Mesozoic Sierran arc. Basaltic to andesitic clasts found within the breccia of Frog Lakes are geochemically similar to modern arc-derived andesites, enriched in fluid-mobile LILEs, indicating that water had been introduced into the mantle wedge by the subducting plate and consequently depleted in less-mobile HFSEs, especially niobium. A subaqueous setting is indicated by the presence of a fine-grained, laminated sedimentary succession between the tuff of Saddlebag Lake and the breccia of Frog Lakes, together with jigsaw fragmentation of Frog Lakes breccia clasts, fluidal margins of some of these clasts, and localized fine-grained laminated sedimentary zones within clast-rich horizons. Although the arc setting remained subaqueous throughout deposition of at least the basal SLP Mesozoic

  15. US outbreak of human Salmonella infections associated with aquatic frogs, 2008-2011.

    Science.gov (United States)

    Mettee Zarecki, Shauna L; Bennett, Sarah D; Hall, Julia; Yaeger, Jill; Lujan, Kate; Adams-Cameron, Marguerite; Winpisinger Quinn, Kim; Brenden, Rita; Biggerstaff, Gwen; Hill, Vincent R; Sholtes, Kari; Garrett, Nancy Marie; Lafon, Patti C; Barton Behravesh, Casey; Sodha, Samir V

    2013-04-01

    Although amphibians are known Salmonella carriers, no such outbreaks have been reported. We investigated a nationwide outbreak of human Salmonella Typhimurium infections occurring predominantly among children from 2008 to 2011. We conducted a matched case-control study. Cases were defined as persons with Salmonella Typhimurium infection yielding an isolate indistinguishable from the outbreak strain. Controls were persons with recent infection with Salmonella strains other than the outbreak strain and matched to cases by age and geography. Environmental samples were obtained from patients' homes; traceback investigations were conducted. We identified 376 cases from 44 states from January 1, 2008, to December 31, 2011; 29% (56/193) of patients were hospitalized and none died. Median patient age was 5 years (range <1-86 years); 69% were children <10 years old (253/367). Among 114 patients interviewed, 69 (61%) reported frog exposure. Of patients who knew frog type, 79% (44/56) reported African dwarf frogs (ADF), a type of aquatic frog. Among 18 cases and 29 controls, illness was significantly associated with frog exposure (67% cases versus 3% controls, matched odds ratio 12.4, 95% confidence interval 1.9-infinity). Environmental samples from aquariums containing ADFs in 8 patients' homes, 2 ADF distributors, and a day care center yielded isolates indistinguishable from the outbreak strain. Traceback investigations of ADFs from patient purchases converged to a common ADF breeding facility. Environmental samples from the breeding facility yielded the outbreak strain. ADFs were the source of this nationwide pediatric predominant outbreak. Pediatricians should routinely inquire about pet ownership and advise families about illness risks associated with animals.

  16. Hibernal habitat selection by Wood Frogs (Lithobates sylvaticus) in a northern New England montane landscape

    Science.gov (United States)

    Groff, Luke A.; Calhoun, Aram J.K.; Loftin, Cynthia S.

    2016-01-01

    Poikilothermic species, such as amphibians, endure harsh winter conditions via freeze-tolerance or freeze-avoidance strategies. Freeze-tolerance requires a suite of complex, physiological mechanisms (e.g., cryoprotectant synthesis); however, behavioral strategies (e.g., hibernal habitat selection) may be used to regulate hibernaculum temperatures and promote overwintering survival. We investigated the hibernal ecology of the freeze-tolerant Wood Frog (Lithobates sylvaticus) in north-central Maine. Our objectives were to characterize the species hibernaculum microclimate (temperature, relative humidity), evaluate hibernal habitat selection, and describe the spatial arrangement of breeding, post-breeding, and hibernal habitats. We monitored 15 frogs during two winters (2011/12: N = 10; 2012/13: N = 5), measured hibernal habitat features at micro (2 m) and macro (10 m) spatial scales, and recorded microclimate hourly in three strata (hibernaculum, leaf litter, ambient air). We compared these data to that of 57 random locations with logistic regression models, Akaike Information Criterion, and Kolmogorov–Smirnov tests. Hibernaculum microclimate was significantly different and less variable than leaf litter, ambient air, and random location microclimate. Model averaging indicated that canopy cover (−), leaf litter depth (+), and number of logs and stumps (+; microhabitat only) were important predictors of Wood Frog hibernal habitat. These habitat features likely act to insulate hibernating frogs from extreme and variable air temperatures. For example, decreased canopy cover facilitates increased snowpack depth and earlier snowpack accumulation and melt. Altered winter temperature and precipitation patterns attributable to climate change may reduce snowpack insulation, facilitate greater temperature variation in the underlying hibernacula, and potentially compromise Wood Frog winter survival.

  17. Persistence at distributional edges: Columbia spotted frog habitat in the arid Great Basin, USA

    Science.gov (United States)

    Arkle, Robert S.; Pilliod, David S.

    2015-01-01

    A common challenge in the conservation of broadly distributed, yet imperiled species is understanding which factors facilitate persistence at distributional edges, locations where populations are often vulnerable to extirpation due to changes in climate, land use, or distributions of other species. For Columbia spotted frogs (Rana luteiventris) in the Great Basin (USA), a genetically distinct population segment of conservation concern, we approached this problem by examining (1) landscape-scale habitat availability and distribution, (2) water body-scale habitat associations, and (3) resource management-identified threats to persistence. We found that areas with perennial aquatic habitat and suitable climate are extremely limited in the southern portion of the species’ range. Within these suitable areas, native and non-native predators (trout and American bullfrogs [Lithobates catesbeianus]) are widespread and may further limit habitat availability in upper- and lower-elevation areas, respectively. At the water body scale, spotted frog occupancy was associated with deeper sites containing abundant emergent vegetation and nontrout fish species. Streams with American beaver (Castor canadensis) frequently had these structural characteristics and were significantly more likely to be occupied than ponds, lakes, streams without beaver, or streams with inactive beaver ponds, highlighting the importance of active manipulation of stream environments by beaver. Native and non-native trout reduced the likelihood of spotted frog occupancy, especially where emergent vegetation cover was sparse. Intensive livestock grazing, low aquatic connectivity, and ephemeral hydroperiods were also negatively associated with spotted frog occupancy. We conclude that persistence of this species at the arid end of its range has been largely facilitated by habitat stability (i.e., permanent hydroperiod), connectivity, predator-free refugia, and a commensalistic interaction with an ecosystem

  18. Road Impacts on Abundance, Call Traits, and Body Size of Rainforest Frogs in Northeast Australia

    Directory of Open Access Journals (Sweden)

    Conrad J. Hoskin

    2010-09-01

    Full Text Available Frogs are potentially sensitive indicators of road impacts, with studies indicating particular susceptibility to road mortality. Calling, i.e., breeding, behavior could also be affected by traffic noise. We investigated effects on frog abundance and calling behavior where a busy highway crosses rainforest stream breeding habitat in northeast Australia. Frog abundance was repeatedly surveyed along five stream transects during a summer breeding season. Abundance of two species, Litoria rheocola and Austrochaperina pluvialis, increased significantly with perpendicular distance from the road along two transects. No trends in abundance were detected for A. pluvialis on two other transects where it was common, or for Litoria serrata on one transect where abundance was sufficient for analysis. Both species with lowered abundance near the road, L. rheocola and A. pluvialis, are rare in road kill statistics along this highway, suggesting road mortality is not the cause of reduced frog abundance near the road. We postulate that lowered abundance may reflect traffic noise effects. We analyzed calls of the International Union for Conservation of Nature endangered species L. rheocola along the one stream transect on which it was common. We found significant trends in two call traits over a very fine scale: both call rate and dominant frequency were significantly higher closer to the road. Furthermore, males were significantly smaller closer to the road. These call and body size trends most likely reflect road impacts, but resolving these is complicated by correlations between traits. Potential mechanisms, effects on fitness, and management recommendations to mitigate the impacts of roads on frogs are outlined.

  19. Hibernation physiology, freezing adaptation and extreme freeze tolerance in a northern population of the wood frog.

    Science.gov (United States)

    Costanzo, Jon P; do Amaral, M Clara F; Rosendale, Andrew J; Lee, Richard E

    2013-09-15

    We investigated hibernation physiology and freeze tolerance in a population of the wood frog, Rana sylvatica, indigenous to Interior Alaska, USA, near the northernmost limit of the species' range. Winter acclimatization responses included a 233% increase in the hepatic glycogen depot that was subsidized by fat body and skeletal muscle catabolism, and a rise in plasma osmolality that reflected accrual of urea (to 106±10 μmol ml(-1)) and an unidentified solute (to ~73 μmol ml(-1)). In contrast, frogs from a cool-temperate population (southern Ohio, USA) amassed much less glycogen, had a lower uremia (28±5 μmol ml(-1)) and apparently lacked the unidentified solute. Alaskan frogs survived freezing at temperatures as low as -16°C, some 10-13°C below those tolerated by southern conspecifics, and endured a 2-month bout of freezing at -4°C. The profound freeze tolerance is presumably due to their high levels of organic osmolytes and bound water, which limits ice formation. Adaptive responses to freezing (-2.5°C for 48 h) and subsequent thawing (4°C) included synthesis of the cryoprotectants urea and glucose, and dehydration of certain tissues. Alaskan frogs differed from Ohioan frogs in retaining a substantial reserve capacity for glucose synthesis, accumulating high levels of cryoprotectants in brain tissue, and remaining hyperglycemic long after thawing. The northern phenotype also incurred less stress during freezing/thawing, as indicated by limited cryohemolysis and lactate accumulation. Post-glacial colonization of high latitudes by R. sylvatica required a substantial increase in freeze tolerance that was at least partly achieved by enhancing their cryoprotectant system.

  20. Identification, synthesis and mass spectrometry of a macrolide from the African reed frog Hyperolius cinnamomeoventris

    Directory of Open Access Journals (Sweden)

    Markus Menke

    2016-12-01

    Full Text Available The contents of the gular glands of the male African reed frog Hyperolius cinnamomeoventris consist of a mixture of aliphatic macrolides and sesquiterpenes. While the known macrolide gephyromantolide A was readily identified, the structure of another major component was suggested to be a tetradecen-13-olide. The synthesis of the two candidate compounds (Z-5- and (Z-9-tetradecen-13-olide revealed the former to be the naturally occurring compound. The synthesis used ring-closing metathesis as key step. While the Hoveyda–Grubbs catalyst furnished a broad range of isomeric products, the (Z-selective Grubbs catalyst lead to pure (Z-products. Analysis by chiral GC revealed the natural frog compound to be (5Z,13S-5-tetradecen-13-olide (1. This compound is also present in the secretion of other hyperoliid frogs as well as in femoral glands of male mantellid frogs such as Spinomantis aglavei. The mass spectra of the synthesized macrolides as well as their rearranged isomers obtained during ring-closing metathesis showed that it is possible to assign the location of the double bond in an unsaturated macrolide on the basis of its EI mass spectrum. The occurrence of characteristic ions can be explained by the fragmentation pathway proposed in the article. In contrast, the localization of a double bond in many aliphatic open-chain compounds like alkenes, alcohols or acetates, important structural classes of pheromones, is usually not possible from an EI mass spectrum. In the article, we present the synthesis and for the first time elucidate the structure of macrolides from the frog family Hyperoliidae.

  1. Population genetics of the Chilean frog Batrachyla Leptopus (Leptodactylidae

    Directory of Open Access Journals (Sweden)

    J.R. Formas

    2000-03-01

    Full Text Available Electrophoretic variation of proteins encoded by 14 loci was analyzed in eight (five continental and three insular populations of the Chilean leptodactylid frog Batrachyla leptopus. The overall proportion of polymorphic loci was estimated to be 18.7% and the average number of alleles per locus, 1.2, while observed and expected heterozygosities were 1.7 and 5.1%, respectively. The estimated coefficient of genetic identity was 0.940; the corresponding figure for genetic distance was 0.063. F-statistics analysis showed a total inbreeding coefficient (Fit of 0.855 and high levels of genetic subdivision (Fst = 0.596 as well as of inbreeding within populations (Fis = 0.640. However, there was only a moderate level of genetic differentiation (Fst = 0.181 between the insular group of populations and the continental group.A variação eletroforética de proteínas codificadas por 14 loci foi analisada em oito populações (5 continentais e 3 insulares da rã leptodactilídea chilena Batrachyla leptopus. A proporção geral de loci polimórficos foi estimada como sendo de 18,7% e o número médio de alelos por loco, 1,2, enquanto que as heterozigosidades observada e esperada foram 1,7 e 5,1%, respectivamente. O coeficiente esperado de identidade genética foi 0,940; o número correspondente para a distância genética foi 0,063. A análise estatística F mostrou um coeficiente de endogamia total (Fit de 0,855 e altos níveis de subdivisão genética (Fst = 0,596, assim como de endogamia dentro das populações (Fis = 0,640. Contudo, houve apenas um nível moderado de diferenciação genética (Fst = 0,181 entre o grupo insular de populações e o grupo continental.

  2. Elucidating the Life History and Ecological Aspects of Allodero hylae (Annelida: Clitellata: Naididae), A Parasitic Oligochaete of Invasive Cuban Tree Frogs in Florida.

    Science.gov (United States)

    Andrews, Jessee M; Childress, Jasmine N; Iakovidis, Triantafilos J; Langford, Gabriel J

    2015-06-01

    Given their ubiquitous nature, it is surprising that more oligochaete annelid worms (Annelida: Clitellata) have not adopted an endoparasitic lifestyle. Exceptions, however, are the understudied members of the genus Dero (Allodero) that parasitize the ureters of tree frogs and toads. This study experimentally explores the life cycle and host specificity of Allodero hylae, the worm's use of chemical cues in host searching, and its seasonal prevalence and abundance over a year-long collection period on the Florida Southern College campus. A total of 2,005 A. hylae was collected from the ureter, urinary bladder, or expressed urine of wild Osteopilus septentrionalis ; a significant positive correlation was found between host snout-vent length and parasite intensity for female but not male hosts. Monthly prevalence of A. hylae reached a peak of 58% in April, but never dropped below 20% in any month; mean abundance peaked March-May, whereas few worms were recovered in December and January. Confirming a parasitic lifestyle, wild-collected hosts with intense infections, typically >40 worms, showed obvious dilatation of the ureter wall, and some young-of-the-year O. septentrionalis exposed to A. hylae in the laboratory were killed by the apparent rupture of the host's ureter. The worm has a direct life cycle: worms expelled in the host's urine are capable of locating and re-infecting other hosts within aquatic microhabitats such as bromeliad tanks, and worms can survive for weeks in a free-living environment, even undergoing a morphological change. Further, chemotaxis assays found a positive response to a tree frog attractant for worms recently removed from hosts. Overall, this study provides the first multifaceted investigation on the life history and ecology of any Allodero spp., which offers new insights into an understudied endoparasitic oligochaete.

  3. Self-cleaning in tree frog toe pads; a mechanism for recovering from contamination without the need for grooming.

    Science.gov (United States)

    Crawford, Niall; Endlein, Thomas; Barnes, W Jon P

    2012-11-15

    Tree frogs use adhesive toe pads for climbing on a variety of surfaces. They rely on wet adhesion, which is aided by the secretion of mucus. In nature, the pads will undoubtedly get contaminated regularly through usage, but appear to maintain their stickiness over time. Here, we show in two experiments that the toe pads of White's tree frogs (Litoria caerulea) quickly recover from contamination through a self-cleaning mechanism. We compared adhesive forces prior to and after contamination of (1) the whole animal on a rotatable platform and (2) individual toe pads in restrained frogs mimicking individual steps using a motorised stage. In both cases, the adhesive forces recovered after a few steps but this took significantly longer in single toe pad experiments from restrained frogs, showing that use of the pads increases recovery. We propose that both shear movements and a 'flushing' effect of the secreted mucus play an important role in shedding particles/contaminants.

  4. Effects of predator exposure on Hsp70 expression and survival in tadpoles of the Common Frog (Rana temporaria)

    National Research Council Canada - National Science Library

    Sorensen, Jesper Givskov; Loeschcke, Volker; Merila, Juha; Laurila, Anssi

    2011-01-01

    ...)—a commonly found response to stress—in tadpoles of the Common Frog ( Rana temporaria L., 1758). In another experiment, we tested the survival of tadpoles in the presence of a free-ranging predator...

  5. lAhoratoire Arago, Banyuls-sur-mer, France

    African Journals Online (AJOL)

    In Gaboon, the frog Aub,iD subsigillata. at least at certain periods of the ~,eats fishes of the genus. Epiplatys. The fish are caught when they jump out ofthc water to escape their aquatic predators, or to look for different surroundings. The African ranid genus Aubria Boulenger is represented by a single species, A. suhsigillata.

  6. Tool path planning of hole-making operations in ejector plate of injection mould using modified shuffled frog leaping algorithm

    Directory of Open Access Journals (Sweden)

    Amol M. Dalavi

    2016-07-01

    Full Text Available Optimization of hole-making operations in manufacturing industry plays a vital role. Tool travel and tool switch planning are the two major issues in hole-making operations. Many industrial applications such as moulds, dies, engine block, automotive parts etc. requires machining of large number of holes. Large number of machining operations like drilling, enlargement or tapping/reaming are required to achieve the final size of individual hole, which gives rise to number of possible sequences to complete hole-making operations on the part depending upon the location of hole and tool sequence to be followed. It is necessary to find the optimal sequence of operations which minimizes the total processing cost of hole-making operations. In this work, therefore an attempt is made to reduce the total processing cost of hole-making operations by applying relatively new optimization algorithms known as shuffled frog leaping algorithm and proposed modified shuffled frog leaping algorithm for the determination of optimal sequence of hole-making operations. An industrial application example of ejector plate of injection mould is considered in this work to demonstrate the proposed approach. The obtained results by the shuffled frog leaping algorithm and proposed modified shuffled frog leaping algorithm are compared with each other. It is seen from the obtained results that the results of proposed modified shuffled frog leaping algorithm are superior to those obtained using shuffled frog leaping algorithm.

  7. Underwater sonar image detection: A combination of non-local spatial information and quantum-inspired shuffled frog leaping algorithm.

    Science.gov (United States)

    Wang, Xingmei; Liu, Shu; Liu, Zhipeng

    2017-01-01

    This paper proposes a combination of non-local spatial information and quantum-inspired shuffled frog leaping algorithm to detect underwater objects in sonar images. Specifically, for the first time, the problem of inappropriate filtering degree parameter which commonly occurs in non-local spatial information and seriously affects the denoising performance in sonar images, was solved with the method utilizing a novel filtering degree parameter. Then, a quantum-inspired shuffled frog leaping algorithm based on new search mechanism (QSFLA-NSM) is proposed to precisely and quickly detect sonar images. Each frog individual is directly encoded by real numbers, which can greatly simplify the evolution process of the quantum-inspired shuffled frog leaping algorithm (QSFLA). Meanwhile, a fitness function combining intra-class difference with inter-class difference is adopted to evaluate frog positions more accurately. On this basis, recurring to an analysis of the quantum-behaved particle swarm optimization (QPSO) and the shuffled frog leaping algorithm (SFLA), a new search mechanism is developed to improve the searching ability and detection accuracy. At the same time, the time complexity is further reduced. Finally, the results of comparative experiments using the original sonar images, the UCI data sets and the benchmark functions demonstrate the effectiveness and adaptability of the proposed method.

  8. Metabolic depression induced by urea in organs of the wood frog, Rana sylvatica: effects of season and temperature.

    Science.gov (United States)

    Muir, Timothy J; Costanzo, Jon P; Lee, Richard E

    2008-03-01

    It has long been suspected that urea accumulation plays a key role in the induction or maintenance of metabolic suppression during extended dormancy in animals from diverse taxa. However, little evidence supporting that hypothesis in living systems exists. We measured aerobic metabolism of isolated organs from the wood frog (Rana sylvatica) in the presence or absence of elevated urea at various temperatures using frogs acclimatized to different seasons. The depressive effect of urea on metabolism was not consistent across organs, seasons, or temperatures. None of the organs from summer frogs, which were tested at 20 degrees C, or from winter frogs tested at 4 degrees C were affected by urea treatment. However, liver, stomach, and heart from spring frogs tested at 4 degrees C had significantly lower metabolic rates when treated with urea as compared with control samples. Additionally, when organs from winter frogs were tested at 10 degrees C, metabolism was significantly decreased in urea-treated liver and stomach by approximately 15% and in urea-treated skeletal muscle by approximately 50%. Our results suggest that the presence of urea depresses the metabolism of living organs, and thereby reduces energy expenditure, but its effect varies with temperature and seasonal acclimatization. The impact of our findings may be wide ranging owing to the number of diverse organisms that accumulate urea during dormancy. (c) 2008 Wiley-Liss, Inc.

  9. Underwater sonar image detection: A combination of non-local spatial information and quantum-inspired shuffled frog leaping algorithm.

    Directory of Open Access Journals (Sweden)

    Xingmei Wang

    Full Text Available This paper proposes a combination of non-local spatial information and quantum-inspired shuffled frog leaping algorithm to detect underwater objects in sonar images. Specifically, for the first time, the problem of inappropriate filtering degree parameter which commonly occurs in non-local spatial information and seriously affects the denoising performance in sonar images, was solved with the method utilizing a novel filtering degree parameter. Then, a quantum-inspired shuffled frog leaping algorithm based on new search mechanism (QSFLA-NSM is proposed to precisely and quickly detect sonar images. Each frog individual is directly encoded by real numbers, which can greatly simplify the evolution process of the quantum-inspired shuffled frog leaping algorithm (QSFLA. Meanwhile, a fitness function combining intra-class difference with inter-class difference is adopted to evaluate frog positions more accurately. On this basis, recurring to an analysis of the quantum-behaved particle swarm optimization (QPSO and the shuffled frog leaping algorithm (SFLA, a new search mechanism is developed to improve the searching ability and detection accuracy. At the same time, the time complexity is further reduced. Finally, the results of comparative experiments using the original sonar images, the UCI data sets and the benchmark functions demonstrate the effectiveness and adaptability of the proposed method.

  10. Anfíbios Anuros do Distrito Federal The Frogs of the Federal District of Brazil

    Directory of Open Access Journals (Sweden)

    Bertha Lutz

    1954-03-01

    Full Text Available The frogs of the Federal District of Brazil are listed and discussed as to habit, biology and ecology. The F. D is situated 22° 54' 24" S. & 43° 10' 21" W Gr. and comprises 1.356 km². Its topography includes sea-shore, maritime scrub, lagoons, plains and marsh, open slopes, forested mountains and great heads of rock. Three thousand feet of altitude are attained at two points. Fifty two different frogs occur in the F.D. Three fifths of them live in open country. Two fifths of these have never been found above the plains; the others range higher but mostly in open country. Their environment offers conditions suitable for average tadpoles and adults. these frogs are more or less unspecialized. There are six genera and thirty species. Two thirds of the latter belong to the type genera of the large neotropical families Bufonidae, Leptodactylidae and Hylidae. Only in the maritime scrub formation are conditions somewhat different. Water for average tadpoles is provided by the lagoons. The xerophytism of the vegetation is, however, so marked that bromeliads growing on the ground provide almost the only appropriate shelter for adult tree-frogs used to sleeping upright on the vegetation. One large Hylid genus lives entirely in them. It is casque-headed and phragmotic, shutting the lumen of the leaf-cup with head used as a plug. Another large Hylid genus shows a lesser degree of the same specialization. (Lutz A & Lutz B, 1939 II. One genus with two species is entirely saxicolous; it lives on wet ledges of rock at all phases of its life history. (B. Lutz 1948. The other two fifths of the frogs from F. D. are montane forest forms. Their environment offers numerous and varied biotopes and is near optimum for adults. There is,however, hardly any standing water available for larvae. These frogs are ecologically diversified. They also show a general trend towards spawning in the adult biotipe, which leads to delayed hatching, semi-aquatic and terrestrial

  11. Cadmium-induced oxidative stress and apoptosis in the testes of frog Rana limnocharis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Hangjun; Cai Chenchen; Shi Cailei; Cao Hui; Han Ziliu [Department of Environmental Sciences, Hangzhou Normal University, Xuelin Road 16, Xiasha Gaojiao Dongqu, Hangzhou, Zhejiang Province, 310036 (China); Jia Xiuying, E-mail: hznujiaxiuying@126.com [Department of Environmental Sciences, Hangzhou Normal University, Xuelin Road 16, Xiasha Gaojiao Dongqu, Hangzhou, Zhejiang Province, 310036 (China)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Cd can cause vacuoles and deformity of the spermatogenic cells in the frog testes. Black-Right-Pointing-Pointer Cd can result in oxidative stress in the frog testes. Black-Right-Pointing-Pointer Cd can induce significantly increase of ROS contents triggered DNA damages in the frog testes. Black-Right-Pointing-Pointer Cd can cause apoptosis in the testes of male R. limnocharis. Black-Right-Pointing-Pointer Apoptosis by Cd in the frog testes is related to Caspase-3, Bax and Bcl-2 genes. - Abstract: This study explored the genetic damage induced by cadmium exposure in the testes of Rana limnocharis. Healthy adult frogs were exposed to 2.5, 5, 7.5, or 10 mg/L of cadmium solution for 14 days. The results showed that exposure to these concentrations increased the levels of reactive oxygen species and malondialdehyde content in the testes, clearly indicating a dose-effect relationship. Moreover, the same dosages of Cd{sup 2+} solution increased glutathione (reduced) content, with the values being significantly different from those observed in the control group (P < 0.01). The comet assay results demonstrated that the DNA damage rate, tail length, and tail moment of samples obtained from frogs exposed to 2.5-7.5 mg/L of cadmium solution significantly increased compared with those of samples obtained from the control group (P < 0.01). These findings suggest that cadmium can induce free radical generation, followed by lipid peroxidation and DNA damage. Ultrastructural observation revealed vacuoles in the spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. Moreover, cadmium exposure induced significant down-regulation of Bcl-2 expression and up-regulation of Bax and caspase-3 expressions. Taken together, these data indicate that cadmium can induce testicular cell apoptosis in R. limnocharis. Exploring the effects of cadmium on the mechanism of reproductive toxicity in amphibians will help provide a

  12. Analysis of skin derived peptides from the Cuyaba Dwarf Frog Physalaemus nattereri by off-line LC MALDI MS/MS

    DEFF Research Database (Denmark)

    Castro, Mariana S; Pires Júnior, Osmindo Rodrigues; Fontes, Wagner

    2017-01-01

    We have investigated the potential for analysis of the complex peptide mixtures secreted from frog skin using off-line LC-MALDI MS/MS. Since only limited information about the sequence of such peptides is available, de novo sequencing followed by Blast search was needed. An automated workflow has...... been applied based on automated collection of the chromatographic fractions on the MALDI target followed by automated recording of the MS/MS spectra of the 10 most intense peaks in each fraction. The MS/MS spectra were submitted to de novo sequencing by the Peaks software and searched for potential...... matches in an amphibian database extracted from UniProt. A number of known skin secreted peptides as well as precursor proteins for these were identified. However, most of the recorded MS/MS data and deduced sequences did not result in matches with the databases. These sequences might serve as a reference...

  13. Karyological and morphometric variation of the North African green frog Pelophylax saharicus (Anura in north-eastern Africa

    Directory of Open Access Journals (Sweden)

    Nabil AMOR, Sarra FARJALLAH, Slim BEN-YACOUB, Paolo MERELLA, Khaled SAID

    2010-12-01

    Full Text Available Morphometric variation of Pelophylax saharicus was analysed using univariate and multivariate statistics, with both traditional and geometric morphometrics, based on 148 specimens from four different geographical localities in Tunisia and Algeria. The results show the existence of three morphotypes in Tunisia and one in Algeria, and indicate a significant degree of variation in morphometric characters between regions. Specimens from the southernmost region have the smallest body size and the greatest morphometric divergence from other populations. This pattern of morphometric variation probably results from phenotypic plasticity in response to local environmental factors. The results of our chromosomal study (C-, Ag-NOR-, endonuclease digestion, DAPI, CMA3 and Q-banding reveal this species to exhibit the plesiomorphic Pelophylax karyotype of 2n = 26 biarmed chromosomes and NORs on the eleventh pair. Similarities and differences of the North African green frog are discussed in relation to the different forms of data collected (chromosomal, morphometric, ecological [Current Zoology 56 (6: 678–686, 2010].

  14. Diversification in a biodiversity hot spot: landscape correlates of phylogeographic patterns in the African spotted reed frog.

    Science.gov (United States)

    Lawson, Lucinda P

    2013-04-01

    The Eastern Afromontane Biodiversity Hotspot is known for microendemism and exceptional population genetic structure. The region's landscape heterogeneity is thought to limit gene flow between fragmented populations and create opportunities for regional adaptation, but the processes involved are poorly understood. Using a combination of phylogeographic analyses and circuit theory, I investigate how characteristics of landscape heterogeneity including regional distributions of slope, rivers and streams, habitat and hydrological basins (drainages) impact genetic distance among populations of the endemic spotted reed frog (Hyperolius substriatus), identifying corridors of connectivity as well as barriers to dispersal. Results show that genetic distance among populations is most strongly correlated to regional and local hydrologic structure and the distribution of suitable habitat corridors, not isolation by distance. Contrary to expectations, phylogeographic structure is not coincident with the two montane systems, but instead corresponds to the split between the region's two major hydrological basins (Zambezi and East Central Coastal). This results in a paraphyletic relationship for the Malawian Highlands populations with respect to the Eastern Arc Mountains and implies that the northern Malawian Highlands are the diversity centre for H. substriatus. Although the Malawian Highlands collectively hold the greatest genetic diversity, individual populations have lower diversity than their Eastern Arc counterparts, with an overall pattern of decreasing population diversity from north to south. Through the study of intraspecific differentiation across a mosaic of ecosystem and geographic heterogeneity, we gain insight into the processes of diversification and a broader understanding of the role of landscape in evolution. © 2013 Blackwell Publishing Ltd.

  15. Polychlorinated biphenyls and toxaphene in Pacific tree frog tadpoles (Hyla regilla) from the California Sierra Nevada, USA

    Science.gov (United States)

    Angermann, Jeffrey E.; Fellers, Gary M.; Matsumura, Fumio

    2002-01-01

    Pacific tree frog (Hyla regilla) tadpoles were collected throughout the Sierra Nevada mountain range, California, USA, in 1996 and 1997 and analyzed for the presence of polychlorinated biphenyls (PCBs) and toxaphene. Whole-tadpole Σ PCB levels ranged from 244 ng/g (wet wt) at lower elevations on the western slope to 1.6 ng/g high on the eastern slope, whereas Σ toxaphene levels ranged from 15.6 to 1.5 ng/g. Linear regression of PCB and toxaphene residue levels versus elevation indicated a significant relationship, with an r2 value of 0.33 for PCB and 0.45 for toxaphene indicating a significant elevation effect on PCB and toxaphene bioaccumulation in Sierra Nevada H. regilla. Tadpole samples from sites in east-facing versus west-facing drainage basins showed significant differences in PCB and toxaphene residue levels, suggesting the possibility of a rain-shadow effect in the long-range atmospheric transport of these contaminants to the Sierra Nevada Mountains.

  16. The demography of Atelopus decline: Harlequin frog survival and abundance in central Panama prior to and during a disease outbreak

    Directory of Open Access Journals (Sweden)

    Rebecca McCaffery

    2015-07-01

    Full Text Available Harlequin frogs (Bufonidae: Atelopus are a species-rich genus of Neotropical toads that have experienced disproportionately severe population declines and extinctions caused by the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd. The genus Atelopus is of high conservation concern, but relatively little is known about the population dynamics and life history of the majority of species. We examined the demography of one population of Atelopus zeteki and two populations of A. varius in central Panama using three to six years of mark-recapture data collected prior to and during an outbreak of Bd. We estimated male survival probabilities prior to the arrival of Bd and sex-specific population sizes for these three populations using state-space Bayesian population models. Prior to the arrival of Bd, monthly apparent survival probabilities were higher for A. varius males than for A. zeteki males, and recaptures among years were low in both species. Abundance of both species varied over time and declined rapidly after the arrival of Bd. Male densities were generally greater than female densities, though female densities were higher or equivalent to males after the arrival of Bd. Estimates of survival and abundance over time may be explained by differences in the use of stream habitat by the two sexes and three populations, both during and between breeding seasons. These estimates provide key baseline population information that can be used to inform reintroductions from captive assurance colonies and studies of extant Atelopus populations as part of conservation and management programs.

  17. Modified shuffled frog leaping algorithm optimized control for air-breathing hypersonic flight vehicle

    Directory of Open Access Journals (Sweden)

    Bingbing Liang

    2016-11-01

    Full Text Available This article addresses the flight control problem of air-breathing hypersonic vehicles and proposes a novel intelligent algorithm optimized control method. To achieve the climbing, cruising and descending flight control of the air-breathing hypersonic vehicle, an engineering-oriented flight control system based on a Proportional Integral Derivative (PID method is designed for the hypersonic vehicle, which including the height loop, the pitch angle loop and the velocity loop. Moreover, as a variant of nature-inspired algorithm, modified shuffled frog leaping algorithm is presented to optimize the flight control parameters and is characterized by better exploration and exploitation than the standard shuffled frog leaping algorithm. A nonlinear model of air-breathing hypersonic vehicle is used to verify the dynamic characteristics achieved by the intelligent flight control system. Simulation results demonstrate that the proposed swarm intelligence optimized PID controllers are effective in achieving better flight trajectory and velocity control performance than the traditional controllers.

  18. [A simple and new type of drop recorder mainly applied in the experiment of frog heart].

    Science.gov (United States)

    Ji, Shu-Mei; Wang, Qing-Shan; Fan, Zhen-Zhong; Sun, Ying

    2004-02-01

    To introduce the manufacture and use of a simple, new type of drop recorder of frog heart. To improve the perfusion device of (see text for symbol) and Straub method. Two electrodes of drop recorder were fixed in an injector of 20 ml. The input tube, output tube and resistance tube were all made of plastic material. This device could be used to observe effects of preload, after-load, hormone and electrolyte on the cardiac output in isolated frog heart. The new type of drop recorder was economical and could be easily operated, it could be also connected to computer. Using the new type of drop recorder, effects of various physical and chemical factors on cardiac function could be observed directly, accurately.

  19. Wet adhesion with application to tree frog adhesive toe pads and tires

    Energy Technology Data Exchange (ETDEWEB)

    Persson, B N J [IFF, FZ-Juelich, 52425 Juelich (Germany)

    2007-09-19

    Strong adhesion between solids with rough surfaces is only possible if at least one of the solids is elastically very soft. Some lizards and spiders are able to adhere (dry adhesion) and move on very rough vertical surfaces due to very compliant surface layers on their attachment pads. Flies, bugs, grasshoppers and tree frogs have less compliant pad surface layers, and in these cases adhesion to rough surfaces is only possible because the animals inject a wetting liquid into the pad-substrate contact area, which generates a relative long-range attractive interaction due to the formation of capillary bridges. In this presentation I will discuss some aspects of wet adhesion for tree frogs and give some comments related to tire applications.

  20. Robust jumping performance and elastic energy recovery from compliant perches in tree frogs.

    Science.gov (United States)

    Astley, Henry C; Haruta, Alison; Roberts, Thomas J

    2015-11-01

    Arboreal animals often move on compliant branches, which may deform substantially under loads, absorbing energy. Energy stored in a compliant substrate may be returned to the animal or it may be lost. In all cases studied so far, animals jumping from a static start lose all of the energy imparted to compliant substrates and performance is reduced. Cuban tree frogs (Osteopilus septentrionalis) are particularly capable arboreal jumpers, and we hypothesized that these animals would be able to recover energy from perches of varying compliance. In spite of large deflections of the perches and consequent substantial energy absorption, frogs were able to regain some of the energy lost to the perch during the recoil. Takeoff velocity was robust to changes in compliance, but was lower than when jumping from flat surfaces. This highlights the ability of animals to minimize energy loss and maintain dependable performance on challenging substrates via behavioral changes. © 2015. Published by The Company of Biologists Ltd.

  1. An Improved Upper Bound for the Critical Probability of the Frog Model on Homogeneous Trees

    Science.gov (United States)

    Lebensztayn, Élcio; Machado, Fábio P.; Popov, Serguei

    2005-04-01

    We study the frog model on homogeneous trees, a discrete time system of simple symmetric random walks whose description is as follows. There are active and inactive particles living on the vertices. Each active particle performs a simple symmetric random walk having a geometrically distributed random lifetime with parameter (1 - p). When an active particle hits an inactive particle, the latter becomes active. We obtain an improved upper bound for the critical parameter for having indefinite survival of active particles, in the case of one-particle-per-vertex initial configuration. The main tool is to construct a class of branching processes which are dominated by the frog model and analyze their supercritical behavior. This approach allows us also to present an upper bound for the critical probability in the case of random initial configuration.

  2. Evidence for a Na+/Ca2+ exchange mechanism in frog skin epithelium

    DEFF Research Database (Denmark)

    Madsen, K H; Brodin, Birger; Nielsen, R

    1999-01-01

    In the present study we investigated the possible existence of a Na+/Ca2+ exchange mechanism in the basolateral membrane of the frog skin epithelium and whether such a mechanism plays a role in the regulation of transepithelial Na+ transport. Cytosolic calcium ([Ca2+]i) was measured with the probe...... in serosal Na+ were followed by stepwise changes in [Ca2+]i. These observations indicate the existence of a Na+/Ca2+ exchange mechanism in the basolateral membrane of the frog skin epithelium. The transepithelial Na+ transport decreased from 13.2+/-1.8 to 9.2+/-1.5 microA cm-2 (n=8, P=0.049) when Na...

  3. Depth perception in frogs and toads a study in neural computing

    CERN Document Server

    House, Donald

    1989-01-01

    Depth Perception in Frogs and Toads provides a comprehensive exploration of the phenomenon of depth perception in frogs and toads, as seen from a neuro-computational point of view. Perhaps the most important feature of the book is the development and presentation of two neurally realizable depth perception algorithms that utilize both monocular and binocular depth cues in a cooperative fashion. One of these algorithms is specialized for computation of depth maps for navigation, and the other for the selection and localization of a single prey for prey catching. The book is also unique in that it thoroughly reviews the known neuroanatomical, neurophysiological and behavioral data, and then synthesizes, organizes and interprets that information to explain a complex sensory-motor task. The book will be of special interest to that segment of the neural computing community interested in understanding natural neurocomputational structures, particularly to those working in perception and sensory-motor coordination. ...

  4. Biotic Resistance to an Alien Amphibian: Larval Competition between Japanese Frogs and Invasive Cane Toads.

    Science.gov (United States)

    Haramura, Takashi; Takeuchi, Hirohiko; Crossland, Michael R; Shine, Richard

    2016-01-01

    Understanding negative effects of native species on introduced taxa may suggest novel ways to control the invasive species by enhancing such effects. Previous studies have reported that the larvae of invasive cane toads (Rhinella marina) are suppressed by competition with the larvae of native anurans in Australia, but not in North America. We conducted laboratory trials to measure the effect of exposure to the larvae of Japanese frogs (Microhyla ornata, Fejervarya sakishimensis, Rhacophorus owstoni) on rates of survival, growth and development of cane toad tadpoles in Ishigaki Island, in southern Japan. Survival rates were not affected by native species, but competition with Dicroglossids and Rhacophorids (but not Microhylids) strongly reduced rates of growth and development in the tadpoles of cane toads. Dicroglossid tadpoles also reduced the body condition to toad tadpoles in addition to effects on SVL and mass. Encouraging populations of native frogs in toad-invaded areas of Japan thus may help to reduce the numbers of invasive cane toads.

  5. DISPERSAL IN THE WOOD FROG (RANA SYLVATICA): IMPLICATIONS FOR GENETIC POPULATION STRUCTURE.

    Science.gov (United States)

    Berven, Keith A; Grudzien, Thaddeus A

    1990-12-01

    Recapture of marked juvenile and adult wood frogs in five Appalachian Mountain ponds showed adults to be 100% faithful to the ponds in which they first bred, but approximately 18% of the juveniles dispersed to breed in ponds other than the one of origin. Effective population sizes were generally smaller than the population censuses and genetic neighborhoods had an average radius of 1,126 meters. Values of standardized genetic variance based on effective population size and mating success were relatively small. Genetic population structure estimated from the dispersal data suggested that ponds within about a 1,000 meter radius should show little genetic differentiation; ponds separated by a distance greater than 1,000 meters should experience little gene flow and show higher genetic differentiation. Wood frogs in these ponds do not show a meta-population structure as suggested for newts. © 1990 The Society for the Study of Evolution.

  6. Effects of D-600 on intramembrane charge movement of polarized and depolarized frog muscle fibers

    OpenAIRE

    1989-01-01

    Intramembrane charge movement has been measured in frog cut skeletal muscle fibers using the triple vaseline gap voltage-clamp technique. Ionic currents were reduced using an external solution prepared with tetraethylammonium to block potassium currents, and O sodium + tetrodotoxin to abolish sodium currents. The internal solution contained 10 mM EGTA to prevent contractions. Both the internal and external solutions were prepared with impermeant anions. Linear capacitive currents were subtrac...

  7. Further Development and Validation of the Frog Embryo Teratogenesis Assay-Xenopus (FETAX).

    Science.gov (United States)

    1992-11-23

    high osmosis water to culture the adults with no temperature bake oven in which glassware can be apparent adverse effects on results. Only non- heated...Toxicol 14(1&2):143-160, 199 1. Laevis. Bull Environ Contain Toxicol 22:159-166, 1979. Friedman M, Rayburn JR, Bantle JA: Developmental toxicology of potato ...160. Friedman, M., Rayburn, J.R., and Bantle, J.A. 1990. Developmental toxicology of potato alkaloids in the Frog Embryo Teratogenesis Assay-Xenopus

  8. A philosophical approach to Emotions: understanding Love’s Knowledge through a Frog in Love

    OpenAIRE

    Murris, Karin

    2009-01-01

    In this paper I offer a philosophical approach to the emotion ‘love’, as a response to more psychological approaches presupposed in ‘emotional intelligence’, ‘emotional literacy’ programmes, or how some Philosophy for Children practitioners interpret ‘caring thinking’. Martha Nussbaum’s philosophy of emotions expressed in her book Love’s Knowledge, and the complex arguments contained within it have been given a narrative context: the picturebook Frog in Love by Max Velthuijs. The narrative co...

  9. Birefringence signals in mammalian and frog myocardium. E-C coupling implications

    OpenAIRE

    1983-01-01

    Birefringence signals from mammalian and frog hearts were studied. The period between excitation and the onset of contraction in which optical signals were free of movement artifact was determined by changes in scattered incandescent light and changes in laser diffraction patterns. The birefringence signal preceding contraction was found to behave as a change in retardation and was not contaminated measurably by linear dichroic or isotropic absorption changes. There were two components of the...

  10. Stabilizing effect of Silene pectin polysaccharide on electrical activity of the sinoatrial area in frog heart.

    Science.gov (United States)

    Golovko, V A; Bushneva, O A

    2007-03-01

    Silenan, a pectin polysaccharide from common catchfly (Silene vulgaris), corrects disorders in the conduction of action potentials between cells of the sinoatrial area of frog heart forming a functional syncytium. Recovery of action potential conduction in the sinoatrial cells was recorded in long-term experiments (>8 h). The effect of silenan manifested mainly against the background of arrhythmic generation and impaired propagation of action potentials.

  11. [Detection of light intensity in the frog retina: evidence from dark and light adaptation].

    Science.gov (United States)

    Izmaĭlov, Ch A; Zimachev, M M

    2010-01-01

    The frog retina was stimulated with light flashes homogeneous in space but not time. The time heterogeneity of stimulation was created by abrupt change of a referent stimulus for a stimulus with different luminance. Such changes form a time pattern, as well as sharp borders of luminance between the neighbor areas of the visual field form a spatial pattern. The electroretinogram recorded in response to presentation of a triad of stimuli: the onset of a short flash of homogeneous light after long dark (or light) adaptation of a retina, brief sequence of the referent and test light flashes varied in luminance, and the offset, with returning to the initial level of adaptation. It was shown that responses of the retina under conditions of time heterogeneity of stimulation could be divided in two types as well as under conditions of spatial heterogeneity. Such a dual change in amplitude confirms our earlier hypothesis on the existence of two mechanisms of luminance coding in the frog retina. The first mechanism encodes power characteristics of light, it forms the information on the absolute level of the environmental luminance. Its activity is connected basically with receptors and cells of the external plexiform layer of the frog's retina. It is responsible for the b-wave of the electroretinogram. The other mechanism associated with RERG is based on a vector code of stimuli. This mechanism forms the information on spatial and time differentiation of the light flow in the visual field and is connected basically with cells of the internal plexiform layer. The results suggest that the frog retina has the individual mechanism for time pattern detection, distinguishing it from the homogeneous light flow in a similar way as in case of spatial light pattern detection. It is possible that the first mechanism is responsible for the detection of any new stimulus in general, irrespective of its specificity, whereas the second mechanism serves for the measurement of suprathreshold

  12. An elusive new species of Marsupial Frog (Anura: Hemiphractidae: Gastrotheca) from the Andes of northern Peru

    OpenAIRE

    William E. Duellman

    2013-01-01

    A new species of marsupial frog, genus Gastrotheca, is described from high-elevation grasslands in the Andes in Región Amazonas in northernPeru, where even calling males are well hidden in deep moss. The new species is distinguished from all congeners by its unique color pattern that includes a narrow, blackbordered, yellow middorsal stripe. The species apparently belongs to the Gastrotheca plumbea Group, which ranges in the Andes from northern Colombia to northern Peru.

  13. Stochastic juvenile--adult models with application to a green tree frog population.

    Science.gov (United States)

    Ackleh, Azmy S; Deng, Keng; Huang, Qihua

    2011-01-01

    We derive several stochastic models from a deterministic population model that describes the dynamics of age-structured juveniles coupled with size-structured adults. Numerical simulation results of the stochastic models are compared with the solution of the deterministic model. These models are then used to understand the effect of demographic stochasticity on the dynamics of an urban green tree frog (Hyla cinerea) population.

  14. An elusive new species of Marsupial Frog (Anura: Hemiphractidae: Gastrotheca from the Andes of northern Peru

    Directory of Open Access Journals (Sweden)

    William E. Duellman

    2013-06-01

    Full Text Available A new species of marsupial frog, genus Gastrotheca, is described from high-elevation grasslands in the Andes in Región Amazonas in northernPeru, where even calling males are well hidden in deep moss. The new species is distinguished from all congeners by its unique color pattern that includes a narrow, blackbordered, yellow middorsal stripe. The species apparently belongs to the Gastrotheca plumbea Group, which ranges in the Andes from northern Colombia to northern Peru.

  15. Factors associated with the catastrophic decline of a cloudforest frog fauna in Guatemala

    OpenAIRE

    Mendelson III, J R; E.D Brodie,Jr; Malone, J H; Acevedo, M E; M.A Baker; N.J Smatresk; Campbell, J. A.

    2004-01-01

    Comparison of recent and historical surveys of frog populations in cloudforest habitat in Sierra de las Minas,Guatemala,indicated population declines and local extirpation of several species.Pathological exams of diseased tadpoles indicated infection by amphibian chytridiomycosis. The local habitat has been severely altered by recent establishment of large-scale leatherleaf fern production.Analysis of water chemistry at our study site suggested increased nitrogenation associated with the leat...

  16. Factors associated with the catastrophic decline of a cloudforest frog fauna in Guatemala

    OpenAIRE

    Mendelson III, J R; Brodie, E. D.; Malone, J H; Acevedo, M E; M.A Baker; N.J Smatresk; Campbell, J. A.

    2014-01-01

    Comparison of recent and historical surveys of frog populations in cloudforest habitat in Sierra de las Minas, Guatemala, indicated population declines and local extirpation of several species. Pathological exams of diseased tadpoles indicated infection by amphibian chytridiomycosis. The local habitat has been severely altered by recent establishment of large-scale leatherleaf fern production. Analysis of water chemistry at our study site suggested increased nitrogenation associated with the ...

  17. Preliminary report on self-healing minefield (frogs) concepts and utility in battle

    Energy Technology Data Exchange (ETDEWEB)

    Greenwalt, R J; Magnoli, D

    2000-01-13

    The purpose of this study is to determine battlefield effectiveness of the self-healing minefield (''Frogs'') concept system compared to basecases of the standard AP/AT (anti-personnel/anti-tank) mixed minefield, the AT (anti-tank) pure minefield, and no minefields. This involves tactical modeling where a basecase with and without mines is compared to the concept system. However, it is first necessary to establish system characteristics and behavior of the Frog mine and minefield in order to do the tactical modeling. This initial report provides emerging insights into various minefield parameters in order to allow better program definition early in the conceptual development. In the following sections of this report, we investigate the self-healing minefield's ground pattern and several concepts for movement (''jump'') of a mine. Basic enemy breaching techniques are compared for the different mine movement concepts. These results are then used in the (Joint Conflict and Tactical Simulation) JCATS tactical model to evaluate minefield effects in a combat situation. The three basecases and the Frogs concept are used against a North Korean mechanized rifle battalion and outcomes are compared. Preliminary results indicate: (1) Possible breaching techniques for the self-healing minefield were proposed and compared through simulation modeling. Of these, the best breaching counter to the self-healing minefield is the ''wide-lane'' breach technique. (2) Several methods for mine movement are tested and the optimal method from this group was selected for use in the modeling. However, continued work is needed on jump criteria; a more sophisticated model may reduce the advantage of the breach counter. (3) The battle scenario used in this study is a very difficult defense for Blue. In the three baseline cases (no mines, AT mines only, and mixed AT/AP minefield), Blue loses. Only in the Frog case does Blue win, and

  18. A Non-Cross-Bridge Stiffness in Activated Frog Muscle Fibers

    OpenAIRE

    Bagni, Maria A.; Cecchi, Giovanni; Colombini, Barbara; Colomo, Francesco

    2002-01-01

    Force responses to fast ramp stretches of various amplitude and velocity, applied during tetanic contractions, were measured in single intact fibers from frog tibialis anterior muscle. Experiments were performed at 14 degrees C at approximately 2.1 microm sarcomere length on fibers bathed in Ringer's solution containing various concentrations of 2,3-butanedione monoxime (BDM) to greatly reduce the isometric tension. The fast tension transient produced by the stretch was followed by a period, ...

  19. New material of Beelzebufo, a hyperossified frog (Amphibia: Anura from the late cretaceous of Madagascar.

    Directory of Open Access Journals (Sweden)

    Susan E Evans

    Full Text Available The extant anuran fauna of Madagascar is exceptionally rich and almost completely endemic. In recent years, many new species have been described and understanding of the history and relationships of this fauna has been greatly advanced by molecular studies, but very little is known of the fossil history of frogs on the island. Beelzebufo ampinga, the first named pre-Holocene frog from Madagascar, was described in 2008 on the basis of numerous disarticulated cranial and postcranial elements from the Upper Cretaceous (Maastrichtian Maevarano Formation of Madagascar. These specimens documented the presence of a hyperossified taxon that differed strikingly from extant Malagasy frogs in its large size and heavy coarse cranial exostosis. Here we describe and analyse new, articulated, and more complete material of the skull, vertebral column, and hind limb, as well as additional isolated elements discovered since 2008. μCT scans allow a detailed understanding of both internal and external morphology and permit a more accurate reconstruction. The new material shows Beelzebufo to have been even more bizarre than originally interpreted, with large posterolateral skull flanges and sculptured vertebral spine tables. The apparent absence of a tympanic membrane, the strong cranial exostosis, and vertebral morphology suggest it may have burrowed during seasonally arid conditions, which have been interpreted for the Maevarano Formation from independent sedimentological and taphonomic evidence. New phylogenetic analyses, incorporating both morphological and molecular data, continue to place Beelzebufo with hyloid rather than ranoid frogs. Within Hyloidea, Beelzebufo still groups with the South American Ceratophryidae thus continuing to pose difficulties with both biogeographic interpretations and prior molecular divergence dates.

  20. A mechanism for diversity in warning signals: Conspicuousness versus toxicity in poison frogs

    OpenAIRE

    Darst, Catherine R; Cummings, Molly E.; Cannatella, David C

    2006-01-01

    Many animals advertise their chemical defense to predators with conspicuous coloration and unpalatability, but little is known about the information in these signal elements. To effectively avoid predation, is it more advantageous to invest in increased conspicuousness or greater noxiousness, or to allocate equally to both signal modalities? Using natural variation among poison frog species measured with spectral reflectance and toxicity assays, we tested the relative importance of warning si...

  1. Collection Development.

    Science.gov (United States)

    School Libraries in Canada, 2002

    2002-01-01

    Includes 21 articles that discuss collection development in Canadian school libraries. Topics include digital collections in school library media centers; print and electronic library resources; library collections; collaborative projects; print-disabled students; informing administrators of the importance of collection development; censorship;…

  2. Shuffled Frog Leaping Algorithm for Preemptive Project Scheduling Problems with Resource Vacations Based on Patterson Set

    Directory of Open Access Journals (Sweden)

    Yi Han

    2013-01-01

    Full Text Available This paper presents a shuffled frog leaping algorithm (SFLA for the single-mode resource-constrained project scheduling problem where activities can be divided into equant units and interrupted during processing. Each activity consumes 0–3 types of resources which are renewable and temporarily not available due to resource vacations in each period. The presence of scarce resources and precedence relations between activities makes project scheduling a difficult and important task in project management. A recent popular metaheuristic shuffled frog leaping algorithm, which is enlightened by the predatory habit of frog group in a small pond, is adopted to investigate the project makespan improvement on Patterson benchmark sets which is composed of different small and medium size projects. Computational results demonstrate the effectiveness and efficiency of SFLA in reducing project makespan and minimizing activity splitting number within an average CPU runtime, 0.521 second. This paper exposes all the scheduling sequences for each project and shows that of the 23 best known solutions have been improved.

  3. Seasonal and spatial comparison of metallothioneins in frog Rana ridibunda from feral populations.

    Science.gov (United States)

    Falfushynska, Halina I; Romanchuk, Liliya D; Stolyar, Oksana B

    2008-11-01

    The aim of this study was to elucidate the seasonal and spatial regularity of the properties of metallothioneins (MTs) from the liver and kidney of the frog Rana ridibunda in rural (R) and urban (U) sites in Western Ukraine. This allowed examination of their possibility use in biomonitoring of environmental quality. The positive correlation for Zn and negative correlation for Cu were reflected between their content in the liver and MTs. The content of MTs was higher in summer compared to other seasons and also at the U site compare to the R site. MTs had been comprised of two chromatographic forms (MT-1 and MT-2/MT-2a), with lesser and variable MT-2/2a in frogs from the U site, particularly in the kidney. MTs accumulated about 75% of Cd in the liver. In summary, the ability MTs to elevate content as a stress response, together with the sensitivity of MT-2, may be explored to understand the health status of the frog in each season, reflecting the higher overall anthropogenic impact at the U site.

  4. Population recovery following decline in an endangered stream-breeding frog (Mixophyes fleayi from subtropical Australia.

    Directory of Open Access Journals (Sweden)

    David Alan Newell

    Full Text Available Amphibians have undergone dramatic declines and extinctions worldwide. Prominent among these have been the stream-breeding frogs in the rainforests of eastern Australia. The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd has been postulated as the primary cause of these declines. We conducted a capture-mark-recapture study over a 7-year period on the endangered Fleay's barred frog (Mixophyes fleayi at two independent streams (30 km apart in order to assess the stability of these populations. This species had undergone a severe decline across its narrow geographic range. Mark-recapture modelling showed that the number of individuals increased 3-10 fold along stream transects over this period. Frog detection probabilities were frequently above 50% but declined as the populations increased. Adult survival was important to overall population persistence in light of low recruitment events, suggesting that longevity may be a key factor in this recovery. One male and female were present in the capture record for >6 years. This study provides an unambiguous example of population recovery in the presence of Bd.

  5. Widespread occurrence of the chytrid fungus batrachochytrium dendrobatidis on oregon spotted frogs (rana pretiosa)

    Science.gov (United States)

    Pearl, C.A.; Bowerman, J.; Adams, M.J.; Chelgren, N.D.

    2009-01-01

    The pathogen Batrachochytrium dendrobatidis (Bd) has been associated with amphibian declines in multiple continents, including western North America. We investigated Bd prevalence in Oregon spotted frog (Rana pretiosa), a species that has declined across its range in the Pacific Northwest. Polymerase chain reaction analysis of skin swabs indicated that Bd was prevalent within populations (420 of 617 juvenile and adults) and widespread among populations (36 of 36 sites) where we sampled R. pretiosa in Oregon and Washington. We rarely detected Bd in R. pretiosa larvae (2 of 72). Prevalence of Bd in postmetamorphic R. pretiosa was inversely related to frog size. We found support for an interactive effect of elevation and sampling date on Bd: prevalence of Bd generally increased with date, but this effect was more pronounced at lower elevations. We also found evidence that the body condition of juvenile R. pretiosa with Bd decreased after their first winter. Our data indicate that some Oregon spotted frog populations are currently persisting with relatively high Bd prevalence, but the risk posed by Bd is unknown. ?? 2010 International Association for Ecology and Health.

  6. Thyrotropin-releasing hormone (TRH promotes wound re-epithelialisation in frog and human skin.

    Directory of Open Access Journals (Sweden)

    Natalia T Meier

    Full Text Available There remains a critical need for new therapeutics that promote wound healing in patients suffering from chronic skin wounds. This is, in part, due to a shortage of simple, physiologically and clinically relevant test systems for investigating candidate agents. The skin of amphibians possesses a remarkable regenerative capacity, which remains insufficiently explored for clinical purposes. Combining comparative biology with a translational medicine approach, we report the development and application of a simple ex vivo frog (Xenopus tropicalis skin organ culture system that permits exploration of the effects of amphibian skin-derived agents on re-epithelialisation in both frog and human skin. Using this amphibian model, we identify thyrotropin-releasing hormone (TRH as a novel stimulant of epidermal regeneration. Moving to a complementary human ex vivo wounded skin assay, we demonstrate that the effects of TRH are conserved across the amphibian-mammalian divide: TRH stimulates wound closure and formation of neo-epidermis in organ-cultured human skin, accompanied by increased keratinocyte proliferation and wound healing-associated differentiation (cytokeratin 6 expression. Thus, TRH represents a novel, clinically relevant neuroendocrine wound repair promoter that deserves further exploration. These complementary frog and human skin ex vivo assays encourage a comparative biology approach in future wound healing research so as to facilitate the rapid identification and preclinical testing of novel, evolutionarily conserved, and clinically relevant wound healing promoters.

  7. Cardiac heterometric response: the interplay between Catestatin and nitric oxide deciphered by the frog heart.

    Science.gov (United States)

    Mazza, Rosa; Pasqua, Teresa; Gattuso, Alfonsina

    2012-06-30

    The length-active tension relation or heterometric regulation (Frank-Starling mechanism) is modulated by nitric oxide (NO) which, released in pulsatile fashion from the beating heart, improves myocardial relaxation and diastolic distensibility. The NO signaling is also implicated in the homeometric regulation exerted by extrinsic factors such as autonomic nervous system, endocrine and humoral agents. In the in vitro working frog heart, the Chromogranin A (CGA)-derived peptide, Catestatin (CTS; bovine CGA344-364), exerts a direct cardio-suppressive action through a NOS-NO-cGMP-mediated mechanism which requires the functional integrity of the endocardial endothelium (EE) and its endothelin-1 B type (ETB) receptor. However, functional interplay between NO and CTS and their role in the Frank-Starling response of the frog heart are lacking. Here we show that CTS improves the sensitivity to preload increases similar to that exerted by NO. This effect is abolished by inhibition of NO synthase (L-NAME), guanylate cyclase (ODQ), protein kinase G (KT5823), PI3K (Wortmannin), as well as by the functional damage of EE (Triton X-100) suggesting that CTS operates through an EE-dependent NO release. On the whole, the use of the avascular frog heart revealed the EE as major sensor-transducer interface between the physical (volume load) and chemical (CTS) stimuli, NO functioning as a connector between heterometric and homeometric regulation. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Effect of aqueous extract of Ipomoea carnea leaf on isolated frog and mouse heart.

    Science.gov (United States)

    Bachhav, K V; Burande, M D; Rangari, V D; Mehta, J K

    1999-11-01

    Ipomoea carnea fam. Convolvulaceae is a poisonous plant and its toxicity is supposed to be due to the cardiac and respiratory failure. The present paper describes the cardiac effect of aqueous extract of the fresh leaves of I. carnea using mouse and frog heart. The aqueous extract produced an initial blockade of isolated frog heart for 5-10 sec followed by dose dependent increase in both amplitude and rate that lasts up to 2 min. Atropine (1 microgram/ml) blocked the initial depressant phase and potentiated the stimulant effect of the aqueous extract. The dose dependent increase in cardiac contractility of aqueous extract was not altered by propranolol or calcium channel blockers like nifedipine or diltiazem. The decrease in sodium chloride concentration or increase in potassium chloride concentration or calcium chloride concentration in physiological salt solution inhibited the responses to aqueous extract while an increase in sodium chloride concentration or decrease in potassium chloride or calcium chloride concentration in physiological salt solution potentiated the responses to the aqueous extract of I. carnea. It may be suggested from the data that aqueous extract of I. carnea produces positive inotropic effect on isolate frog heart possibly by sodium extrusion or release of the intracellular calcium.

  9. Identification of alpha1-adrenergic receptors and their involvement in phosphoinositide hydrolysis in the frog heart.

    Science.gov (United States)

    Lazou, Antigone; Gaitanaki, Catherine; Vaxevanellis, Spiros; Pehtelidou, Anastasia

    2002-07-01

    The aim of this study was to characterize alpha(1)-adrenergic receptors in frog heart and to examine their related signal transduction pathway. alpha(1)-Adrenergic binding sites were studied in purified heart membranes using the specific alpha(1)-adrenergic antagonist [(3)H]prazosin. Analysis of the binding data indicated one class of binding sites displaying a K(d) of 4.19 +/- 0.56 nM and a B(max) of 14.66 +/- 1.61 fmol/mg original wet weight. Adrenaline, noradrenaline, or phenylephrine, in the presence of propranolol, competed with [(3)H]prazosin binding with a similar potency and a K(i) value of about 10 microM. The kinetics of adrenaline binding was closely related to its biological effect. Adrenaline concentration dependently increased the production of inositol phosphates in the heart in the presence or absence of propranolol. Maximal stimulation was about 8.5-fold, and the half-maximum effective concentration was 30 and 21 microM in the absence and presence of propranolol, respectively. These data clearly show that alpha(1)-adrenergic receptors are coupled to the phosphoinositide hydrolysis in frog heart. To our knowledge, this is the first direct evidence supporting the presence of functional alpha(1)-adrenergic receptors in the frog heart. Copyright 2002 Wiley-Liss, Inc.

  10. [Cardiac electric field at the period of depolarization and repolarization of the frog heart ventricle].

    Science.gov (United States)

    Vaĭkshnoraĭte, M A; Belogolova, A S; Vitiazev, V A; Azarov, Ia E; Shmakov, D N

    2008-01-01

    Multichannel mapping of electrical field on heart ventricle epicardium and the body surface in frogs Rana esculenta and Rana temporaria was performed at periods of the ventricular myocardium depolarization and repolarization. The zone of the epicardium early depolarization is located on epicardium of the ventricle base posterior wall, while the late depolarization zone--on its apex and on the base anterior wall. The total vector of sequence of the ventricle epicardium depolarization is directed from the base to the apex. The zone of the early repolarization is located in the apical area, while that of the late one--in the area of the base. On the frog body surface the cardioelectric field with the cranial zone of negative and the caudal zone of positive potentials is formed before the appearance of the QRS complex on ECG. At the period of the heart ventricle repolarization the zone of the cardioelectric field negative potentials is located in the cranial, while that of the positive ones--in the body surface caudal parts. The cardioelectric field on the frog body surface at the periods of depolarization and repolarization of the ventricle myocardium reflects adequately the projection of sequence of involvement with excitation and of distribution of potentials on epicardium.

  11. Activation and repolarization patterns in the ventricular epicardium under sinus rhythm in frog and rabbit hearts.

    Science.gov (United States)

    Azarov, Jan E; Shmakov, Dmitry N; Vityazev, Vladimir A; Roshchevskaya, Irina M; Roshchevsky, Mikhail P

    2007-03-01

    Our study compared the contributions of activation sequence and local repolarization durations distribution in the organization of epicardial repolarization in animals with fast (rabbit) and slow (frog) myocardial activation under sinus rhythm. Activation times, repolarization times and activation-recovery intervals (ARI) were obtained from ventricular epicardial unipolar electrograms recorded in 13 Chinchilla rabbits (Oryctolagus cuniculus) and 10 frogs (Rana temporaria). In frogs, depolarization travels from the atrioventricular ring radially. ARIs increased progressively from the apex to the middle portion and finally to the base (502+/-75, 557+/-73, 606+/-79 ms, respectively; Pfrogs (17+/-3 vs. 44+/-18 ms; P<0.001). ARI durations were 120+/-37, 143+/-45, and 163+/-40 ms in the left ventricular apex, left, and right ventricular bases, respectively (P<0.05). In both species, repolarization sequence was directed from apex to base according to the ARI distribution with dispersion of repolarization being higher than that of activation (P<0.001). Thus, excitation spread sequence and velocity per se do not play a crucial role in the formation of ventricular epicardial repolarization pattern, but the chief factor governing repolarization sequences is the distribution of local repolarization durations.

  12. Importance of riparian remnants for frog species diversity in a highly fragmented rainforest

    Science.gov (United States)

    Rodríguez-Mendoza, Clara; Pineda, Eduardo

    2010-01-01

    Tropical forests undergo continuous transformation to other land uses, resulting in landscapes typified by forest fragments surrounded by anthropogenic habitats. Small forest fragments, specifically strip-shaped remnants flanking streams (referred to as riparian remnants), can be particularly important for the maintenance and conservation of biodiversity within highly fragmented forests. We compared frog species diversity between riparian remnants, other forest fragments and cattle pastures in a tropical landscape in Los Tuxtlas, Mexico. We found similar species richness in the three habitats studied and a similar assemblage structure between riparian remnants and forest fragments, although species composition differed by 50 per cent. Frog abundance was halved in riparian remnants compared with forest fragments, but was twice that found in pastures. Our results suggest that riparian remnants play an important role in maintaining a portion of frog species diversity in a highly fragmented forest, particularly during environmentally stressful (hot and dry) periods. In this regard, however, the role of riparian remnants is complementary, rather than substitutive, with respect to the function of other forest fragments within the fragmented forest. PMID:20554561

  13. Species tree estimation of North American chorus frogs (Hylidae: Pseudacris) with parallel tagged amplicon sequencing.

    Science.gov (United States)

    Barrow, Lisa N; Ralicki, Hannah F; Emme, Sandra A; Lemmon, Emily Moriarty

    2014-06-01

    The field of phylogenetics is changing rapidly with the application of high-throughput sequencing to non-model organisms. Cost-effective use of this technology for phylogenetic studies, which often include a relatively small portion of the genome but several taxa, requires strategies for genome partitioning and sequencing multiple individuals in parallel. In this study we estimated a multilocus phylogeny for the North American chorus frog genus Pseudacris using anonymous nuclear loci that were recently developed using a reduced representation library approach. We sequenced 27 nuclear loci and three mitochondrial loci for 44 individuals on 1/3 of an Illumina MiSeq run, obtaining 96.5% of the targeted amplicons at less than 20% of the cost of traditional Sanger sequencing. We found heterogeneity among gene trees, although four major clades (Trilling Frog, Fat Frog, crucifer, and West Coast) were consistently supported, and we resolved the relationships among these clades for the first time with strong support. We also found discordance between the mitochondrial and nuclear datasets that we attribute to mitochondrial introgression and a possible selective sweep. Bayesian concordance analysis in BUCKy and species tree analysis in (*)BEAST produced largely similar topologies, although we identify taxa that require additional investigation in order to clarify taxonomic and geographic range boundaries. Overall, we demonstrate the utility of a reduced representation library approach for marker development and parallel tagged sequencing on an Illumina MiSeq for phylogenetic studies of non-model organisms. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. The biological significance of acoustic stimuli determines ear preference in the music frog.

    Science.gov (United States)

    Xue, Fei; Fang, Guangzhan; Yang, Ping; Zhao, Ermi; Brauth, Steven E; Tang, Yezhong

    2015-03-01

    Behavioral and neurophysiological studies support the idea that right ear advantage (REA) exists for perception of conspecific vocal signals in birds and mammals. Nevertheless, few studies have focused on anuran species that typically communicate through vocalization. The present study examined the direction and latencies of orientation behaviors in Emei music frogs (Babina daunchina) produced in response to six auditory stimuli emitted by a speaker placed directly behind the subjects. The stimuli included male advertisement calls produced from within burrow nests, which have been shown to be highly sexually attractive (HSA), calls produced from outside burrows, which are of low sexual attractiveness (LSA), screech calls produced when frogs are attacked by snakes, white noise, thunder and silence. For all sound stimuli except the screech, the frogs preferentially turned to the right. Right ear preference was strongest for HSA calls. For the screech and thunder stimuli, there was an increased tendency for subjects to move further from the speaker rather than turning. These results support the idea that in anurans, right ear preference is associated with perception of positive or neutral signals such as the conspecific advertisement call and white noise, while a left ear preference is associated with perception of negative signals such as predatory attack. © 2015. Published by The Company of Biologists Ltd.

  15. Climatic influences on the breeding biology of the agile frog ( Rana dalmatina)

    Science.gov (United States)

    Combes, Magali; Pinaud, David; Barbraud, Christophe; Trotignon, Jacques; Brischoux, François

    2018-02-01

    Severe population declines of amphibians have been shown to be attributed to climate change. Nevertheless, the various mechanisms through which climate can influence population dynamics of amphibians remain to be assessed, notably to disentangle the relative synergetic or antagonistic influences of temperature and precipitations on specific life history stages. We investigated the impact of rainfall and temperature on the egg-clutch abundance in a population of agile frog ( Rana dalmatina) during 29 years (1987-2016) on 14 breeding sites located in Brenne Natural Park, France. Specifically, we examined the influence of environmental conditions occurring during five temporal windows of the year cycle corresponding to specific life history stages. Overall, our results suggest that the year-to-year fluctuations of egg-clutch abundances in Brenne Natural Park were partly dependent on local climatic conditions (rainfall and temperature). Climate seemed to influence breeding frogs during the autumn-winter period preceding reproduction. Spring and summer conditions did not influence reproduction. Additionally, we failed to detect effects of climatic conditions on newly metamorphosed individuals. Other factors such as density dependence and inter-specific interactions with introduced predators are likely to play a significant role in reproduction dynamics of the studied frog populations.

  16. Helminth parasites of the leopard frog Lithobates sp. Colima (Amphibia: Ranidae) from Colima, Mexico.

    Science.gov (United States)

    Cabrera-Guzmán, Elisa; Garrido-Olvera, Lorena; León-Règagnon, Virginia

    2010-08-01

    The helminth fauna inhabiting Lithobates sp. Colima from Ticuizitán, Colima, Mexico, comprises 10 species: 4 digeneans ( Clinostomum sp., Glypthelmins quieta , Haematoloechus sp., and Langeronia macrocirra ), 5 nematodes ( Aplectana itzocanensis , Cosmocerca podicipinus , Foleyellides striatus , Oswaldocruzia subauricularis , and Rhabdias sp.), and 1 cestode (Cyclophyllidea). Glypthelmins quieta , L. macrocirra , and A. itzocanensis represent new host records. These observations, added to previous records from Acapulco, Guerrero, Mexico, indicate that the helminth fauna of Lithobates sp. from Colima comprises 25 taxa. Frogs are being parasitized by 3 infection routes: ingestion of intermediate host, skin penetration by larval forms, and transmission by vectors. Species of Aplectana , Cosmocerca , Foleyellides , and Oswaldocruzia occurred in high prevalence in Colima, similar to a previous study on the same frog species from Guerrero. In Colima, Glypthelmins , Haematoloechus , and Rhabdias also occurred in high prevalence. Haematoloechus species reached the highest mean intensity in both localities. The semiaquatic habits of this species of frog and the availability of particular feeding resources appear to determine the helminth composition and infection levels; however, co-speciation events also play an important role structuring these helminth communities.

  17. The Potential of Frog Skin-Derived Peptides for Development into Therapeutically-Valuable Immunomodulatory Agents

    Directory of Open Access Journals (Sweden)

    Jelena M. Pantic

    2017-12-01

    Full Text Available The aim of this article is to review the immunoregulatory actions of frog skin-derived peptides in order to assess their potential as candidates for immunomodulatory or anti-inflammatory therapy. Frog skin peptides with demonstrable immunomodulatory properties have been isolated from skin secretions of a range of species belonging to the families Alytidae, Ascaphidae, Discoglossidae, Leptodactylidae, Pipidae and Ranidae. Their effects upon production of inflammatory and immunoregulatory cytokines by target cells have been evaluated ex vivo and effects upon cytokine expression and immune cell activity have been studied in vivo by flow cytometry after injection into mice. The naturally-occurring peptides and/or their synthetic analogues show complex and variable actions on the production of proinflammatory (TNF-α, IL-1β, IL-12, IL-23, IL-8, IFN-γ and IL-17, pleiotropic (IL-4 and IL-6 and immunosuppressive (IL-10 and TGF-β cytokines by peripheral and spleen cells, peritoneal cells and/or isolated macrophages. The effects of frenatin 2.1S include enhancement of the activation state and homing capacity of Th1-type lymphocytes and NK cells in the mouse peritoneal cavity, as well as the promotion of their tumoricidal capacities. Overall, the diverse effects of frog skin-derived peptides on the immune system indicate their potential for development into therapeutic agents.

  18. Combined Effects of Pesticides and Trematode Infections on Hourglass Tree Frog Polypedates cruciger.

    Science.gov (United States)

    Jayawardena, Uthpala A; Rohr, Jason R; Navaratne, Ayanthi N; Amerasinghe, Priyanie H; Rajakaruna, Rupika S

    2016-03-01

    The impact of widespread and common environmental factors, such as chemical contaminants, on infectious disease risk in amphibians is particularly important because both chemical contaminants and infectious disease have been implicated in worldwide amphibian declines. Here we report on the lone and combined effects of exposure to parasitic cercariae (larval stage) of the digenetic trematode, Acanthostomum burminis, and four commonly used pesticides (insecticides: chlorpyrifos, dimethoate; herbicides: glyphosate, propanil) at ecologically relevant concentrations on the survival, growth, and development of the common hourglass tree frog, Polypedates cruciger Blyth 1852. There was no evidence of any pesticide-induced mortality on cercariae because all the cercariae successfully penetrated each tadpole host regardless of pesticide treatment. In isolation, both cercarial and pesticide exposure significantly decreased frog survival, development, and growth, and increased developmental malformations, such as scoliosis, kyphosis, and also edema and skin ulcers. The combination of cercariae and pesticides generally posed greater risk to frogs than either factor alone by decreasing survival or growth or increasing time to metamorphosis or malformations. The exception was that lone exposure to chlorpyrifos had higher mortality without than with cercariae. Consistent with mathematical models that suggest that stress should increase the impact of generalist parasites, the weight of the evidence from the field and laboratory suggests that ecologically relevant concentrations of agrochemicals generally increase the threat that trematodes pose to amphibians, highlighting the importance of elucidating interactions between anthropogenic activities and infectious disease in taxa of conservation concern.

  19. Colour and pattern change against visually heterogeneous backgrounds in the tree frog Hyla japonica.

    Science.gov (United States)

    Kang, Changku; Kim, Ye Eun; Jang, Yikweon

    2016-03-02

    Colour change in animals can be adaptive phenotypic plasticity in heterogeneous environments. Camouflage through background colour matching has been considered a primary force that drives the evolution of colour changing ability. However, the mechanism to which animals change their colour and patterns under visually heterogeneous backgrounds (i.e. consisting of more than one colour) has only been identified in limited taxa. Here, we investigated the colour change process of the Japanese tree frog (Hyla japonica) against patterned backgrounds and elucidated how the expression of dorsal patterns changes against various achromatic/chromatic backgrounds with/without patterns. Our main findings are i) frogs primarily responded to the achromatic differences in background, ii) their contrasting dorsal patterns were conditionally expressed dependent on the brightness of backgrounds, iii) against mixed coloured background, frogs adopted intermediate forms between two colours. Using predator (avian and snake) vision models, we determined that colour differences against different backgrounds yielded perceptible changes in dorsal colours. We also found substantial individual variation in colour changing ability and the levels of dorsal pattern expression between individuals. We discuss the possibility of correlational selection on colour changing ability and resting behaviour that maintains the high variation in colour changing ability within population.

  20. High dispersal in a frog species suggests that it is vulnerable to habitat fragmentation

    Science.gov (United States)

    Funk, W. Chris; Greene, Allison E; Corn, Paul Stephen; Allendorf, Fred W

    2005-01-01

    Global losses of amphibian populations are a major conservation concern and their causes have generated substantial debate. Habitat fragmentation is considered one important cause of amphibian decline. However, if fragmentation is to be invoked as a mechanism of amphibian decline, it must first be established that dispersal is prevalent among contiguous amphibian populations using formal movement estimators. In contrast, if dispersal is naturally low in amphibians, fragmentation can be disregarded as a cause of amphibian declines and conservation efforts can be focused elsewhere. We examined dispersal rates in Columbia spotted frogs (Rana luteiventris) using capture–recapture analysis of over 10 000 frogs in combination with genetic analysis of microsatellite loci in replicate basins. We found that frogs had exceptionally high juvenile dispersal rates (up to 62% annually) over long distances (>5 km), large elevation gains (>750 m) and steep inclines (36° incline over 2 km) that were corroborated by genetic data showing high gene flow. These findings show that dispersal is an important life-history feature of some amphibians and suggest that habitat fragmentation is a serious threat to amphibian persistence. PMID:17148116

  1. Oviduct modifications in foam-nesting frogs, with emphasis on the genus Leptodactylus (Amphibia, Leptodactylidae)

    Science.gov (United States)

    Furness, Andrew I.; McDiarmid, Roy W.; Heyer, W. Ronald; Zug, George R.

    2010-01-01

    Various species of frogs produce foam nests that hold their eggs during development. We examined the external morphology and histology of structures associated with foam nest production in frogs of the genus Leptodactylus and a few other taxa. We found that the posterior convolutions of the oviducts in all mature female foam-nesting frogs that we examined were enlarged and compressed into globular structures. This organ-like portion of the oviduct has been called a "foam gland" and these structures almost certainly produce the secretion that is beaten by rhythmic limb movements into foam that forms the nest. However, the label "foam gland" is a misnomer because the structures are simply enlarged and tightly folded regions of the pars convoluta of the oviduct, rather than a separate structure; we suggest the name pars convoluta dilata (PCD) for this feature. Although all the foam-nesters we examined had a pars convoluta dilata, its size and shape showed considerable interspecific variation. Some of this variation likely reflects differences in the breeding behaviors among species and in the size, type, and placement of their foam nests. Other variation, particularly in size, may be associated with the physiological periodicity and reproductive state of the female, her age, and/or the number of times she has laid eggs.

  2. When dinner is dangerous: toxic frogs elicit species-specific responses from a generalist snake predator.

    Science.gov (United States)

    Phillips, Ben; Shine, Richard

    2007-12-01

    In arms races between predators and prey, some evolved tactics are unbeatable by the other player. For example, many types of prey are inedible because they have evolved chemical defenses. In this case, prey death removes any selective advantage of toxicity to the prey but not the selective advantage to a predator of being able to consume the prey. In the absence of effective selection for postmortem persistence of the toxicity then, some chemical defenses probably break down rapidly after prey death. If so, predators can overcome the toxic defense simply by waiting for that breakdown before consuming the prey. Floodplain death adders (Acanthophis praelongus) are highly venomous frog-eating elapid snakes native to northern Australia. Some of the frogs they eat are nontoxic (Litoria nasuta), others produce gluelike mucus when seized by a predator (Limnodynastes convexiusculus), and one species (Litoria dahlii) is dangerously toxic to snakes. Both the glue and the toxin degrade within about 20 min of prey death. Adders deal with these prey types in different and highly stereotyped ways: they consume nontoxic frogs directly but envenomate and release the other taxa, waiting until the chemical defense loses its potency before consuming the prey.

  3. Neuronal intermediate filaments in the developing tongue of the frog Rana esculenta

    Directory of Open Access Journals (Sweden)

    K Zuwala

    2009-06-01

    Full Text Available The expression of several neuronal intermediate filament (NIF proteins was investigated in the tongue of metamorphosing tadpoles (stage 38-45 of Gosner and in adult individuals of the frog, Rana esculenta by means of immunohistochemistry. Results showed that nerve fibres at early stages of tongue development expressed peripherin (a NIF protein usually found in differentiating neurones as well as the light- and medium molecular weight NIF polypeptide subunits (NF-L and NF-M, respectively; in the adult frog, peripherin was still found in nerve fibres reaching the fungiform papilla together with NF-M, but NF-L immunoreactivity was absent therein. Clusters of epithelial cells expressing peripherin were found in the early developing tongue before differentiation of taste organs, and NF-L and NF-H immunoreactivities were present in basal (Merkel cells of the adult frog taste disc. Results indicate that neurones innervating the adult frog’s taste disc maintain a certain plasticity in their cytoskeleton and that neuronal-like cells are present in the undifferentiated and differentiated tongue epithelium possibly playing a role in the developing and mature taste organ.

  4. Developmental toxicity of two common corn pesticides to the endangered southern bell frog (Litoria raniformis)

    Energy Technology Data Exchange (ETDEWEB)

    Choung, Catherine B., E-mail: Catherine.Choung@mq.edu.au [Department of Biological Sciences, Macquarie University, Sydney, NSW 2109 (Australia); Hyne, Ross V. [Ecotoxicology and Environmental Contaminants Section, Office of Environment and Heritage, PO Box 29, Lidcombe, NSW 1825 (Australia); Mann, Reinier M. [Centre for Environmental Sustainability, University of Technology - Sydney, PO Box 123, Broadway, NSW 2007 (Australia); Stevens, Mark M. [EH Graham Centre for Agricultural Innovation (Industry and Investment NSW and Charles Sturt University), Yanco Agricultural Institute, Private Mail Bag, Yanco, NSW 2703 (Australia); Hose, Grant C. [Department of Biological Sciences, Macquarie University, Sydney, NSW 2109 (Australia)

    2011-10-15

    To examine the link between corn agriculture and the observed decline of the endangered southern bell frog (SBF), the effects of two corn crop pesticides on larval growth and development were investigated. Tadpoles were exposed to terbufos sulfone (10 {mu}g/L), a major breakdown product of the insecticide terbufos, and the herbicide atrazine (25 {mu}g/L) individually and as a mixture until the completion of metamorphosis. Atrazine did not interact synergistically with terbufos sulfone or result in significant effects on growth and development alone, although there was some indication of accelerated metamorphosis in the pilot study. Terbufos sulfone alone and as a mixture (terbufos/atrazine) significantly slowed larval development and ultimately delayed metamorphosis. The observed developmental effects from an environmentally relevant concentration of terbufos sulfone indicates a risk posed by this persistent degradation product to the endangered SBF, which breeds and develops in the rice bays adjacent to corn fields treated with pesticides. - Highlights: > The effect of terbufos sulfone and atrazine on larval growth and development was investigated. > Terbufos sulfone alone significantly slowed development and delayed metamorphosis of tadpoles. > Atrazine had no observable effects alone nor did it interact synergistically with terbufos sulfone. > The developmental effects indicates a risk to endangered southern bell frogs in the irrigation area. > The results highlight the toxicological importance of some pesticide breakdown products. - A breakdown product of the insecticide terbufos retards development and delays metamorphosis of southern bell frog tadpoles.

  5. Pulmonary and cutaneous O₂gas exchange: a student laboratory exercise in the frog.

    Science.gov (United States)

    Tattersall, Glenn J; Currie, Suzanne; LeBlanc, Danielle M

    2013-03-01

    Gas exchange in animals is ultimately diffusion based, generally occurring across dedicated respiratory organs. In many aquatic amphibians, however, multiple modes of gas exchange exist, allowing for the partitioning of O2 uptake and CO2 excretion between respiratory organs with different efficiencies. For example, due to the physical properties of O2 being vastly different between air and water phases, the lung and skin play disproportionately important roles in O2 uptake. Many aquatic frogs are renowned for their cutaneous gas exchange capacity, where often the majority of CO2 is excreted across the skin. Furthermore, the roles of these gas exchange organs change with the animal's behavior. Under diving conditions, most of the frog's gas exchange needs must be met by the skin. In this article, we describe an interactive undergraduate laboratory that allows a class of students to share equipment while assessing pulmonary and cutaneous respiration in frogs provided with an air/water choice and under enforced dive conditions. Concepts explored in this laboratory exercise include animal energetics, diving reflex, pulmonary and cutaneous gas exchange processes, diffusion-based gas flux, and O2 debt.

  6. Susceptibility of the endangered frog Dendropsophus meridensis to the pathogenic fungus Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Villarroel, Leomar; García, Carmen Zulay; Nava-González, Francisco; Lampo, Margarita

    2013-11-25

    Chytridiomycosis is an emerging disease that has driven some amphibian species to extinction while leaving others apparently unharmed. Its causative agent, Batrachochytrium dendrobatidis (Bd), now persists endemically in many amphibian communities. Understanding host species response to Bd infection is critical for managing chytridiomycosis because the epidemiology of this disease is host-specific. Dendropsophus meridensis is an endangered hylid frog endemic to the Venezuelan Andes. This species is sympatric with the American bullfrog Lithobates catesbeianus, an introduced species known to act as a reservoir for Bd. High prevalence of infection and high zoospore burdens in wild populations of D. meridensis in the Venezuelan Andes suggested some tolerance for Bd. However, experimental exposure of post-metamorphic frogs resulted in 53% mortality, a value that represents a 14-fold increase in the odds of dying compared to control frogs. Repeated diagnostics using real-time polymerase chain reaction assays demonstrated that individuals that died accumulated a higher number of zoospores than those that survived, although this value was lower than the mean zoospore burdens observed in natural populations. Given the susceptibility of D. meridensis to a strain of Bd isolated from a nearby population of bullfrogs, we emphasize the need to limit the dispersion of this invasive species.

  7. The use of clamping grips and friction pads by tree frogs for climbing curved surfaces.

    Science.gov (United States)

    Endlein, Thomas; Ji, Aihong; Yuan, Shanshan; Hill, Iain; Wang, Huan; Barnes, W Jon P; Dai, Zhendong; Sitti, Metin

    2017-02-22

    Most studies on the adhesive mechanisms of climbing animals have addressed attachment against flat surfaces, yet many animals can climb highly curved surfaces, like twigs and small branches. Here we investigated whether tree frogs use a clamping grip by recording the ground reaction forces on a cylindrical object with either a smooth or anti-adhesive, rough surface. Furthermore, we measured the contact area of fore and hindlimbs against differently sized transparent cylinders and the forces of individual pads and subarticular tubercles in restrained animals. Our study revealed that frogs use friction and normal forces of roughly a similar magnitude for holding on to cylindrical objects. When challenged with climbing a non-adhesive surface, the compressive forces between opposite legs nearly doubled, indicating a stronger clamping grip. In contrast to climbing flat surfaces, frogs increased the contact area on all limbs by engaging not just adhesive pads but also subarticular tubercles on curved surfaces. Our force measurements showed that tubercles can withstand larger shear stresses than pads. SEM images of tubercles revealed a similar structure to that of toe pads including the presence of nanopillars, though channels surrounding epithelial cells were less pronounced. The tubercles' smaller size, proximal location on the toes and shallow cells make them probably less prone to buckling and thus ideal for gripping curved surfaces. © 2017 The Authors.

  8. Thyrotropin-releasing hormone (TRH) promotes wound re-epithelialisation in frog and human skin.

    Science.gov (United States)

    Meier, Natalia T; Haslam, Iain S; Pattwell, David M; Zhang, Guo-You; Emelianov, Vladimir; Paredes, Roberto; Debus, Sebastian; Augustin, Matthias; Funk, Wolfgang; Amaya, Enrique; Kloepper, Jennifer E; Hardman, Matthew J; Paus, Ralf

    2013-01-01

    There remains a critical need for new therapeutics that promote wound healing in patients suffering from chronic skin wounds. This is, in part, due to a shortage of simple, physiologically and clinically relevant test systems for investigating candidate agents. The skin of amphibians possesses a remarkable regenerative capacity, which remains insufficiently explored for clinical purposes. Combining comparative biology with a translational medicine approach, we report the development and application of a simple ex vivo frog (Xenopus tropicalis) skin organ culture system that permits exploration of the effects of amphibian skin-derived agents on re-epithelialisation in both frog and human skin. Using this amphibian model, we identify thyrotropin-releasing hormone (TRH) as a novel stimulant of epidermal regeneration. Moving to a complementary human ex vivo wounded skin assay, we demonstrate that the effects of TRH are conserved across the amphibian-mammalian divide: TRH stimulates wound closure and formation of neo-epidermis in organ-cultured human skin, accompanied by increased keratinocyte proliferation and wound healing-associated differentiation (cytokeratin 6 expression). Thus, TRH represents a novel, clinically relevant neuroendocrine wound repair promoter that deserves further exploration. These complementary frog and human skin ex vivo assays encourage a comparative biology approach in future wound healing research so as to facilitate the rapid identification and preclinical testing of novel, evolutionarily conserved, and clinically relevant wound healing promoters.

  9. A Threshold Dosage of Testosterone for Female-to-Male Sex Reversal in Rana rugosa Frogs.

    Science.gov (United States)

    Oike, Akira; Kodama, Maho; Nakamura, Yoriko; Nakamura, Masahisa

    2016-10-01

    Androgens play a critical role in testicular differentiation in many species of vertebrates. While female-to-male sex reversal can be induced by testosterone (T) in some species of amphibians, the mechanism still remains largely unknown even at the histological level. In this study, we determined a threshold dosage of T to induce female-to-male sex reversal in the Japanese frog Rana (R.) rugosa. Tadpoles were allowed to metamorphose into frogs with T present in the rearing water. At 0.2 ng/mL T, female frogs formed tissue comprising a mixture of ovary and testis, the so-called ovotestis, the size of which was significantly smaller than the wild-type ovary. Histological changes occurring in the oocytes of T-treated ovaries induced oocyte degeneration in the masculinizing ovaries leading to their final disappearance. In parallel, many germ cells emerged in the cortex of the ovotestis and, later, in the medulla as well. RT-PCR analysis revealed upregulated expression of CYP17 and Dmrt1 but not 17βHSD in the ovotestis, and downregulation of Pat1a expression. Furthermore, immunohistology revealed CYP17-positive signals in the cortex of the masculinizing ovary, spreading throughout the whole area as the testis developed. These results indicate that oocytes are sensitive to T in the ovary of R. rugosa and that male-type germ cells expand in the masculinizing gonad (testis) contemporaneous with oocyte disappearance. © 2016 Wiley Periodicals, Inc.

  10. Helpful invaders: Can cane toads reduce the parasite burdens of native frogs?

    Directory of Open Access Journals (Sweden)

    Felicity B.L. Nelson

    2015-12-01

    Full Text Available Many invading species have brought devastating parasites and diseases to their new homes, thereby imperiling native taxa. Potentially, though, invaders might have the opposite effect. If they take up parasites that otherwise would infect native taxa, but those parasites fail to develop in the invader, the introduced species might reduce parasite burdens of the native fauna. Similarly, earlier exposure to the other taxon's parasites might ‘prime’ an anuran's immune system such that it is then able to reject subsequent infection by its own parasite species. Field surveys suggest that lungworm counts in native Australian frogs decrease after the arrival of invasive cane toads (Rhinella marina, and laboratory studies confirm that native lungworm larvae enter, but do not survive in, the toads. In laboratory trials, we confirmed that the presence of anurans (either frogs or toads in an experimental arena reduced uptake rates of lungworm larvae by anurans that were later added to the same arena. However, experimental exposure to lungworms from native frogs did not enhance a toad's ability to reject subsequent infection by its own lungworm species.

  11. Reproductive phenology of the tomato frog, Dyscophus antongili, in an urban pond of Madagascar's east coast

    Directory of Open Access Journals (Sweden)

    Ori Segev

    2012-12-01

    Full Text Available Based on daily monitoring around an urban pond in the coastal town of Maroantsetra, from 2003-2011, we provide an analysis of the yearly reproductive activity of the tomato frog (Dyscophus antongilii, a large-sized and prominent red-coloured microhylid frog from north-eastern Madagascar. Frogs were observed all year round but despite the limited climatic seasonality in the region it was possible to identify a high activity period between January-May and a lower activity period between June-December. Freshly laid eggs were found in all months except November, and with highest incidence between January and May, while calling was heard in all months. We found a positive correlation between daily adult counts and minimum air temperature. On the contrary rainfall did not significantly predict activity, although boosts of calling and egg-laying especially in the austral winter were observed after heavy rainfall events. We define D. antongilii in Maroantsetra as a sporadic wet season breeder that reproduces at irregular intervals following heavy rain events.

  12. Disentangling genetic vs. environmental causes of sex determination in the common frog, Rana temporaria

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    Merilä Juha

    2008-01-01

    Full Text Available Abstract Background Understanding of sex ratio dynamics in a given species requires understanding its sex determination system, as well as access for reliable tools for sex identification at different life stages. As in the case of many other amphibians, the common frogs (Rana temporaria do not have well differentiated sex chromosomes, and an identification of individuals' genetic sex may be complicated by sex reversals. Here, we report results of studies shedding light on the sex determination system and sex ratio variation in this species. Results A microsatellite locus RtSB03 was found to be sex-linked in four geographically disparate populations, suggesting male heterogamy in common frogs. However, in three other populations examined, no or little evidence for sex-linkage was detected suggesting either ongoing/recent recombination events, and/or frequent sex-reversals. Comparison of inheritance patterns of alleles in RtSB03 and phenotypic sex within sibships revealed a mixed evidence for sex-linkage: all individuals with male phenotype carried a male specific allele in one population, whereas results were more mixed in another population. Conclusion These results make sense only if we assume that the RtSB03 locus is linked to male sex determination factor in some, but not in all common frog populations, and if phenotypic sex-reversals – for which there is earlier evidence from this species – are frequently occurring.

  13. Evidence for an intrinsic factor promoting landscape divergence in Madagascan leaf-litter frogs

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    Katharina C. Wollenberg Valero

    2015-05-01

    Full Text Available The endemic Malagasy frog radiations are an ideal model system to study patterns and processes of speciation in amphibians. Large-scale diversity patterns of these frogs, together with other endemic animal radiations, led to the postulation of new and the application of known hypotheses of species diversification causing diversity patterns in this biodiversity hotspot. Both extrinsic and intrinsic factors have been studied in a comparative framework, with extrinsic factors usually being related to the physical environment (landscape, climate, river catchments, mountain chains, and intrinsic factors being clade-specific traits or constraints (reproduction, ecology, morphology, physiology. Despite some general patterns emerging from such large-scale comparative analyses, it became clear that the mechanism of diversification in Madagascar may vary among clades, and may be a multifactorial process. In this contribution, I test for intrinsic factors promoting population-level divergence within a clade of terrestrial, diurnal leaf-litter frogs (genus Gephyromantis that has previously been shown to diversify according to extrinsic factors. Landscape genetic analyses of the microendemic species G. enki and its widely distributed, larger sister species G. boulengeri over a rugged landscape in the Ranomafana area shows that genetic variance of the smaller species cannot be explained by landscape resistance alone. Both topographic and riverine barriers are found to be important in generating this divergence. This case study yields additional evidence for the probable importance of body size in lineage diversification.

  14. Ghrelin receptor in two species of anuran amphibian, bullfrog (Rana catesbeiana and Japanese tree frog (Hyla japonica

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    Hiroyuki eKaiya

    2011-09-01

    Full Text Available We identified cDNA encoding a functional growth hormone secretagogue-receptor 1a (GHS-R1a, ghrelin receptor in two species of anuran amphibian, bullfrog (Rana catesbeiana and Japanese tree frog (Hyla japonica. Deduced receptor protein for bullfrog and Japanese tree frog (tree frog was comprised of 374- and 371-amino acids, respectively. The two receptors showed 86% identity with each other, and phylogenetic analysis revealed that the two receptors belong to the same category with tetrapods. In functional analyses, ghrelin and GHS-R1a agonists increased intracellular Ca2+ concentration in HEK293 cell that transfected each receptor cDNA, but ligand selectivity of ghrelin with Ser3 and Thr3 was not observed between the two receptors. Bullfrog GHS-R1a mRNA was mainly expressed in the brain, stomach and testis. In the brain, the gene expression was detected in the diencephalon and mesencephalon, but not in the pituitary. Tree frog GHS-R1a mRNA was predominantly expressed in the gastrointestinal tract and ovary, but not detected in the pituitary. In bullfrog stomach, GHS-R1a mRNA expression increased at 10 days after fasting, but not in the brain. In tree frog, GHS-R1a mRNA expression increased in the brain, stomach and ventral skin by 10-days fasting, and in the stomach and ventral skin by a dehydration treatment. Intracerebroventricular injection of ghrelin in dehydrated tree frog did not affect water absorption from the ventral skin. These results suggest that ghrelin is involved in energy homeostasis and possibly in osmoregulation in frogs.

  15. Comparative pathology and ecological implications of two myxosporean parasites in native Australian frogs and the invasive cane toad.

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    Ashlie Hartigan

    Full Text Available Myxosporean parasites Cystodiscus axonis and C. australis are pathogens of native and exotic Australian frog species. The pathology and ecological outcomes of infection with these parasites were investigated in this study. Gliosis was correlated to Cystodiscus axonis plasmodia in the brains of (9/60 tadpoles and (3/9 adult endangered Green and golden bell frogs using ordinal regression. Severe host reactions to C. axonis (haemorrhage, necrosis, and vasulitis were observed in the brains of threatened Southern bell frogs (8/8, critically endangered Booroolong frogs (15/44 and Yellow spotted bell frogs (3/3. Severe brain lesions were associated with behavioural changes, neurological dysfunction, and spontaneous death. Both C. axonis and C. australis develop in the bile ducts of tadpoles, the plasmodia were significantly associated with biliary hyperplasia, inflammation and the loss of hepatocytes in (34/72 Green and golden bell frog tadpoles using ordinal regression. These lesions were so severe that in some cases 70% of the total liver was diseased. Normal liver function in tadpoles is necessary for metamorphosis, metabolism, and immune function. We postulate that this extensive liver damage would have significant host health impacts. Severe hepatic myxosporidiosis was more prevalent in tadpoles examined in autumn and winter (overwintered, suggestive of delayed metamorphosis in infected tadpoles, which would have serious flow-on effects in small populations. We compared the sensitivity of histopathology and species-specific PCR in the detection of C. australis and C. axonis. PCR was determined to be the most sensitive method (detection limit 1 myxospore equivalent of ribosomal DNA. Histology, however, had the advantage of assessing the impact of the parasite on the host. It was concluded that these parasites have the potential for significant ecological impacts, because of their high prevalence of infection and their ability to cause disease in

  16. Trichobothrial mediation of an aquatic escape response: Directional jumps by the fishing spider, Dolomedes triton, foil frog attacks

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    Robert B. Suter

    2003-07-01

    Full Text Available Fishing spiders (Pisauridae frequent the surfaces of ponds and streams and thereby expose themselves to predation by a variety of aquatic and semi-aquatic vertebrates. To assess the possibility that the impressive jumps of fishing spiders from the water surface function in evading attacks by frogs, attacks by bullfrogs (Rana catesbiana and green frogs (R. clamitans on Dolomedes triton were studied. Both the attack dynamics of the frogs and the evasive behaviors of the spiders were recorded at 250 frames per second. A freeze-dried bullfrog, propelled toward spiders with acceleration, posture, and position that approximated the natural attack posture and dynamics, was used to assess the spiders' behavior. Qualitatively, the spiders responded to these mock-attacks just as they had to attacks by live frogs: jumping (N=29 jumps, 56.9% of instances, rearing the legs nearest the attacking frog (N=15, 29.4%, or showing no visible response (N=7, 13.7%. Spiders that jumped always did so away (in the vertical plane from the attack (mean =137° vs. vertical at 90° or horizontally toward the frog at 0°. The involvement of the trichobothria (leg hairs sensitive to air movements, and the eyes as sensory mediators of the evasion response was assessed. Spiders with deactivated trichobothria were significantly impaired relative to intact and sham-deactivated spiders, and relative to spiders in total darkness. Thus, functional trichobothria, unlike the eyes, are both necessary and sufficient mediators of the evasion response. Measurements of air flow during frog attacks suggest that an exponential rise in flow velocity is the airborne signature of an attack.

  17. Differential uptake of gold nanoparticles by 2 species of tadpole, the wood frog (Lithobates sylvaticus) and the bullfrog (Lithobates catesbeianus).

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    Thompson, Lucas B; Carfagno, Gerardo L F; Andresen, Kurt; Sitton, Andrea J; Bury, Taylor; Lee, Laura L; Lerner, Kevin T; Fong, Peter P

    2017-12-01

    Engineered nanoparticles are aquatic contaminants of emerging concern that exert ecotoxicological effects on a wide variety of organisms. We exposed cetyltrimethylammonium bromide-capped spherical gold nanoparticles to wood frog and bullfrog tadpoles with conspecifics and in combination with the other species continuously for 21 d, then measured uptake and localization of gold. Wood frog tadpoles alone and in combination with bullfrog tadpoles took up significantly more gold than bullfrogs. Bullfrog tadpoles in combination with wood frogs took up significantly more gold than controls. The rank order of weight-normalized gold uptake was wood frogs in combination > wood frogs alone > bullfrogs in combination > bullfrogs alone > controls. In all gold-exposed groups of tadpoles, gold was concentrated in the anterior region compared with the posterior region of the body. The concentration of gold nanoparticles in the anterior region of wood frogs both alone and in combination with bullfrogs was significantly higher than the corresponding posterior regions. We also measured depuration time of gold in wood frogs. After 21 d in a solution of gold nanoparticles, tadpoles lost >83% of internalized gold when placed in gold-free water for 5 d. After 10 d in gold-free water, tadpoles lost 94% of their gold. After 15 d, gold concentrations were below the level of detection. Our finding of differential uptake between closely related species living in similar habitats with overlapping geographical distributions argues against generalizing toxicological effects of nanoparticles for a large group of organisms based on measurements in only one species. Environ Toxicol Chem 2017;36:3351-3358. © 2017 SETAC. © 2017 SETAC.

  18. Human-assisted invasions of pacific islands by litoria frogs: a case study of the bleating tree frog on Lord Howe Island.

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    T Lynette Plenderleith

    Full Text Available There are substantial differences among taxonomic groups in their capacity to reach remote oceanic islands via long-distance overwater dispersal from mainland regions. Due to their permeable skin and intolerance of saltwater, amphibians generally require human-assisted dispersal to reach oceanic islands. Several Litoria frog species have been introduced to remote islands throughout the Pacific Ocean region. Lord Howe Island (LHI is an oceanic island that lies approximately 600 km east of the Australian mainland and has a diverse, endemic biota. The bleating tree frog (Litoria dentata is native to mainland eastern Australia, but was accidentally introduced to LHI in the 1990s, yet its ecology and potential impact on LHI has remained unstudied. We used a mitochondrial phylogeographical approach to determine that L. dentata was introduced from the Ballina region in northeastern New South Wales. The founding population was likely accidentally introduced with cargo shipped from the mainland. We also completed the first detailed investigation of the distribution, ecology and habitat use of L. dentata on LHI. The species is widespread on LHI and is prevalent in human habitat, cattle pasture and undisturbed forest. We discuss the potential impact of introduced Litoria species on Pacific islands and outline what biosecurity protocols could be implemented to prevent the introduction of further amphibian species to the ecologically sensitive oceanic area.

  19. Human-assisted invasions of pacific islands by litoria frogs: a case study of the bleating tree frog on Lord Howe Island.

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    Plenderleith, T Lynette; Smith, Katie L; Donnellan, Stephen C; Reina, Richard D; Chapple, David G

    2015-01-01

    There are substantial differences among taxonomic groups in their capacity to reach remote oceanic islands via long-distance overwater dispersal from mainland regions. Due to their permeable skin and intolerance of saltwater, amphibians generally require human-assisted dispersal to reach oceanic islands. Several Litoria frog species have been introduced to remote islands throughout the Pacific Ocean region. Lord Howe Island (LHI) is an oceanic island that lies approximately 600 km east of the Australian mainland and has a diverse, endemic biota. The bleating tree frog (Litoria dentata) is native to mainland eastern Australia, but was accidentally introduced to LHI in the 1990s, yet its ecology and potential impact on LHI has remained unstudied. We used a mitochondrial phylogeographical approach to determine that L. dentata was introduced from the Ballina region in northeastern New South Wales. The founding population was likely accidentally introduced with cargo shipped from the mainland. We also completed the first detailed investigation of the distribution, ecology and habitat use of L. dentata on LHI. The species is widespread on LHI and is prevalent in human habitat, cattle pasture and undisturbed forest. We discuss the potential impact of introduced Litoria species on Pacific islands and outline what biosecurity protocols could be implemented to prevent the introduction of further amphibian species to the ecologically sensitive oceanic area.

  20. Recovery of frog and lizard communities following primary habitat alteration in Mizoram, Northeast India

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    Rawat Gopal S

    2004-08-01

    Full Text Available Abstract Background Community recovery following primary habitat alteration can provide tests for various hypotheses in ecology and conservation biology. Prominent among these are questions related to the manner and rate of community assembly after habitat perturbation. Here we use space-for-time substitution to analyse frog and lizard community assembly along two gradients of habitat recovery following slash and burn agriculture (jhum in Mizoram, Northeast India. One recovery gradient undergoes natural succession to mature tropical rainforest, while the other involves plantation of jhum fallows with teak Tectona grandis monoculture. Results Frog and lizard communities accumulated species steadily during natural succession, attaining characteristics similar to those from mature forest after 30 years of regeneration. Lizards showed higher turnover and lower augmentation of species relative to frogs. Niche based classification identified a number of guilds, some of which contained both frogs and lizards. Successional change in species richness was due to increase in the number of guilds as well as the number of species per guild. Phylogenetic structure increased with succession for some guilds. Communities along the teak plantation gradient on the other hand, did not show any sign of change with chronosere age. Factor analysis revealed sets of habitat variables that independently determined changes in community and guild composition during habitat recovery. Conclusions The timescale of frog and lizard community recovery was comparable with that reported by previous studies on different faunal groups in other tropical regions. Both communities converged on primary habitat attributes during natural vegetation succession, the recovery being driven by deterministic, nonlinear changes in habitat characteristics. On the other hand, very little faunal recovery was seen even in relatively old teak plantation. In general, tree monocultures are unlikely to