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Sample records for natterjack toad bufo

  1. Ranking landscape development scenarios affecting natterjack toad (Bufo calamita) population dynamics in Central Poland.

    Science.gov (United States)

    Franz, Kamila W; Romanowski, Jerzy; Johst, Karin; Grimm, Volker

    2013-01-01

    When data are limited it is difficult for conservation managers to assess alternative management scenarios and make decisions. The natterjack toad (Bufo calamita) is declining at the edges of its distribution range in Europe and little is known about its current distribution and abundance in Poland. Although different landscape management plans for central Poland exist, it is unclear to what extent they impact this species. Based on these plans, we investigated how four alternative landscape development scenarios would affect the total carrying capacity and population dynamics of the natterjack toad. To facilitate decision-making, we first ranked the scenarios according to their total carrying capacity. We used the software RAMAS GIS to determine the size and location of habitat patches in the landscape. The estimated carrying capacities were very similar for each scenario, and clear ranking was not possible. Only the reforestation scenario showed a marked loss in carrying capacity. We therefore simulated metapopulation dynamics with RAMAS taking into account dynamical processes such as reproduction and dispersal and ranked the scenarios according to the resulting species abundance. In this case, we could clearly rank the development scenarios. We identified road mortality of adults as a key process governing the dynamics and separating the different scenarios. The renaturalisation scenario clearly ranked highest due to its decreased road mortality. Taken together our results suggest that road infrastructure development might be much more important for natterjack toad conservation than changes in the amount of habitat in the semi-natural river valley. We gained these insights by considering both the resulting metapopulation structure and dynamics in the form of a PVA. We conclude that the consideration of dynamic processes in amphibian conservation management may be indispensable for ranking management scenarios. PMID:23734223

  2. Modelling the extinction risk of isolated populations of natterjack toad Bufo calamita

    Directory of Open Access Journals (Sweden)

    F. Meyer

    2001-09-01

    Full Text Available Many local populations of the natterjack toad Bufo calamita in Germany are endangered. Due to the fragmentation and destruction of natural habitats by man, toads have often been forced to switch to secondary habitats. The permanent existence of these habitats is uncertain. Habitat and area requirements have been investigated in various parts of Germany in recent years. Our study uses field observations from sites in Halle (Saxony-Anhalt and List (Schleswig-Holstein as a basis for analyses of the population dynamics under different environmental conditions. Deterministic trends of these populations are calculated with the help of a Leslie matrix consisting of average parameters for mortality and reproduction. For a more thorough analysis we use a stochastic simulation model in order to assess survival probabilities of local toad populations. This model also takes into account environmental fluctuations affecting mortality and reproduction. Using scenarios from different locations, a sensitivity analysis of the parameters indicates which management options are the most promising to preserve a population. Our results indicate that the mortality rates of juveniles and the availability of spawning ground have the greatest influence on a population’s survival. Consequently, habitat management should focus on these aspects. In addition, we investigate the risk of extinction for different reproductive strategies. Natterjack toad populations observed in the field actually follow a strategy with three breeding periods. We find that this strategy supports the survival of the population better than strategies with less periods, which are more likely to result in a complete breeding failure during one season.

  3. Contrasting patterns of quantitative and neutral genetic variation in locally adapted populations of the natterjack toad, Bufo calamita

    OpenAIRE

    Go?mez-mestre, Iva?n; Tejedo, Miguel

    2004-01-01

    The relative importance of natural selection and genetic drift in determining patterns of phenotypic diversity observed in nature is still unclear. The natterjack toad (Bufo calamita) is one of a few amphibian species capable of breeding in saline ponds, even though water salinity represents a considerable stress for them. Results from two common-garden experiments showed a pattern of geographic variation in embryonic salinity tolerance among populations from either fresh or brackish environm...

  4. Microsatellite analysis of the natterjack toad ( Bufo calamita ) in Denmark: populations are islands in a fragmented landscape

    DEFF Research Database (Denmark)

    Allentoft, Morten E.; Siegismund, Hans Redlef

    2009-01-01

    The European natterjack toad (Bufo calamita) has declined rapidly in recent years, primarily due to loss of habitat, and in Denmark it is estimated that 50% of the isolated populations are lost each decade. To efficiently manage and conserve this species and its genetic diversity, knowledge of the genetic structure is crucial. Based on nine polymorphic microsatellite loci, the genetic diversity, genetic structure and gene flow were investigated at 12 sites representing 5-10% of the natterjack toad localities presently known in Denmark. The expected heterozygosity (H E) within each locality was generally low (range: 0.18-0.43). Further analyses failed to significantly correlate genetic diversity with population size, degree of isolation and increasing northern latitude, indicating a more complex combination of factors in determining the present genetic profile. Genetic differentiation was high (overall ? = 0.29) and analyses based on a Bayesian clustering method revealed that the dataset constituted 11 geneticclusters, defining nearly all sampling sites as distinct populations. Contemporary gene flow among populations was undetectable in nearly all cases, and the failure to detect a pattern of isolation by distance within major regions supported this apparent lack of a gene flow continuum. Indications of a genetic bottleneck were found in three populations. The analyses suggest that the remaining Bufo calamita populations in Denmark are genetically isolated, and represent independent units in a highly fragmented gene pool. Future conservation management of this species is discussed in light of these results.

  5. Effects of temperature on embryonic and larval development and growth in the natterjack toad (Bufo calamita in a semi-arid zone

    Directory of Open Access Journals (Sweden)

    Sanuy, D.

    2008-06-01

    Full Text Available Temperature affects the duration of embryonic and larval periods in amphibians. Plasticity in time to metamorphosis is especially important in amphibian populations of Mediterranean semi-arid zones where temperatures are high and precipitation is low, increasing the rate of pond desiccation. In order to test the influence of water temperature on the larval development and growth of the natterjack toad (Bufo calamita, we collected two spawns in a semi¿arid zone at Balaguer (Lleida, NE Iberian peninsula. Approximately 50 (+/-10 eggs (stage 14-16 were raised in the lab at different temperature conditions: 10, 15, 20, 22.5 and 25ºC with 12:12 photoperiod. The results show a lengthening of development time with decreasing temperatures and a better survival performance of B. calamita to high temperatures. However, mean size at metamorphosis was not different across treatments, thus, suggesting that this population of B. calamita requires a minimum size to complete the metamorphosis. This study is the first approach to examine the effects that climatic factors have on the growth and development of B. calamita in semi-arid zones.

  6. Thyroid anatomy and topography of toad (Bufo marinus ictericus)

    International Nuclear Information System (INIS)

    The autoradiographic method is used for the study of the toad's thyroid of Bufo marinus ictericus by 131I. Histolological proceedings are done. Comparative evaluations with bibliographic informations are presented. (M.A.C.)

  7. Atypical course of myiasis in toad Bufo bufo.

    Czech Academy of Sciences Publication Activity Database

    Zavadil, V.; Kotlík, Petr

    Chambéry : Université de Savoie, 1998. s. -. [SEH Societas Europeae Herpetologica /9./. 25.08.1998-29.08.1998, Chambéry] R&D Projects: GA AV ?R KSK6005114 Keywords : Bufo bufo Subject RIV: EG - Zoology

  8. Behavior of toads, Bufo bufo, in a dynamic environment.

    Science.gov (United States)

    Lychakov, D V

    2009-01-01

    Susceptibility to motion sickness was tested by exposing free moving toads to rotation of a stimulator modeled after an amusement park Ferris Wheel. The stimulator provided a gentle stimulation of frequency 0.25 Hz and centrifugal acceleration 0.143 g during 120 min or more without external visual cues. No emetic or prodromal behavioral response was elicited during or after rotation. During rotation the amount of motor activity in most toads increased evidently. The most active toads attempted to climb out of the test chamber. It was inferred that experimental rotation was rather a stressful stimulus which initiated an escape response. In addition, during rotation the number of eye retractions and urination incidences increased, but appetite after rotation was inhibited. During rotation the motionless toads performed small regular head movements with period equal to rotation period of stimulator. These oscillations were probably vestibular (otolith) reaction to oscillating acceleration. The proposed resonance hypothesis gives a general idea of why lower vertebrates are immune to motion sickness. PMID:20448334

  9. Intoxicación aguda en perro por toxinas de sapo (Bufo bufo - Acute intoxication in a dog by toxins of a toad (Bufo bufo

    Directory of Open Access Journals (Sweden)

    Fernández-Palacios, O´Connor, Rocío

    2009-04-01

    Full Text Available ResumenLas intoxicaciones por toxinas de sapo no son frecuentes en España y su incidencia es mayor en primavera y verano. En este trabajo describimos un caso de intoxicación aguda de una perra de 4 años de edad tras la aprehensión de un sapo (Bufo bufo en la zona de Huelva. Los signos de una intoxicación comenzaron a los 15 minutos de entrar en contacto con el sapo muriendo a las 3 horas sin responder al tratamiento suministrado (corticoides, atropina, fluidoterapia y acepromazina. Aunque el diagnóstico fue precoz, a pesar del tratamiento se produjo la muerte en 3 horas.SummaryIntoxications by toad toxins are not frequent in Spain, and its incidence is greater in spring and summer. In this work it is described a case of an acute intoxication of a dog of 4 years old by toad toxins (Bufo bufo in the area of Huelva. The animal began to show signs of intoxication 15 minutes after the contact with the toad, dying 3 hours later without any response to the provided treatment (corticoids, atropine, fluidotherapy and acepromazine. Although the diagnosis was precocious and the treatment was administrated, after 3 hours the animal died.

  10. SEXUAL DIFFERENCES IN THE ECOLOGY AND HABITAT SELECTION OF WESTERN TOADS (BUFO BOREAS) IN NORTHEASTERN OREGON

    OpenAIRE

    Bull, Evelyn L.

    2006-01-01

    Several species of toads (family Bufonidae), including the Western Toad (Bufo boreas) have declined in thewestern United States. Information on toad ecology and habitat use is essential to determine potential causes for populationdeclines, as is the potential relationship between this information and disturbance events. Aspects of western toad survival,mortality, movements, habitat selection, and diet were investigated at five study areas in northeastern Oregon duringsummers of 2002-2005. Of ...

  11. Bufo toads and bufotenine: fact and fiction surrounding an alleged psychedelic.

    Science.gov (United States)

    Lyttle, T; Goldstein, D; Gartz, J

    1996-01-01

    This paper investigates the supposedly psychedelic Bufo toad and the allegedly psychedelic drug bufotenine, which is contained in the skin and glands of this toad. The bufo toad has held a place in human mythologies and medicines worldwide since archaic times. Used by ancient peoples for a variety of purposes, its most spectacular effects, according to lore, involve magical and shamanic or occult uses for casting spells and for divination. In the Middle Ages, the Bufo toad was celebrated as a panacea and persecuted as a powerful poison. More recently, in the 1960s the Bufo toad was resurrected as a countercultural icon, with people purportedly licking or smoking the secretions to get high. Bufotenine has been at the center of a scientific debate since its discovery in 1893. This paper examines the extensive literature surrounding the Bufo toad and bufotenine, and untangles many of the myths and the misinformation that continue to vex both science and popular reporting. Finally, to promote further investigation, a comprehensive bibliography is provided that charts the history of the Bufo toad and bufotenine. PMID:8895112

  12. Diazinon mediated biochemical changes in the African toad (Bufo regularis

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    Uche Ochei

    2012-12-01

    Full Text Available The sublethal toxicity of diazinon to the adult African toad, Bufo regularis was assessed using an integration of biomarkers. Changes in acetylcholinesterase (AChE, corticosterone and total protein levels were assessed in the serum, brain, liver, lungs and gastrointestinal tract (GIT and the results supported by bioaccumulation data. The biomarkers were chosen as indicators of key physiological functions: AChE for neurotoxicity, corticosterone and total protein levels as indicators of oxidative stress. Toads were exposed to 0.01, 0.02, 0.03 and 0.04 g/L for 28 days. Brain AChE activity reduced by 96% in the highest concentration (0.04 g/L compared to the control brain. Similarly, AChE activities in serum, liver, lungs and GIT tissues (88%, 88%, 87, 87% umg-1 protein respectively were also inhibited in the toads. Corticosterone and total protein levels in the tissues decreased compared to the control. The accumulation results obtained showed accumulation in the tissues (liver>serum>brain> lung>GIT, with a direct relationship between tissue concentration and changes in the biochemical indices. The alterations in all the indices were significantly concentration dependent. The biomarkers described in this study could be useful complementary indices in the risk assessment of diazinon pesticide.

  13. HABITAT PATCH OCCUPANCY BY THE TOADS (BUFO PUNCTATUS) IN A NATURALLY FRAGMENTED, DESERT LANDSCAPE

    Science.gov (United States)

    Amphibians are often thought to have a metapopulation structure, which may render them vulnerable to habitat fragmentation. The red-spotted toad (Bufo punctatus) in the southwestern USA and Mexico commonly inhabits wetlands that have become much smaller and fewer since the late...

  14. Determination of impacts on the endangered Wyoming toad (Bufo baxteri) at Mortenson National Wildlife Refuge from ammonium nitrate concentrations

    US Fish and Wildlife Service, Department of the Interior — The endangered Wyoming toad Bufo baxteri is found only as a reintroduced population at Mortenson NWR in the Laramie Plains of southeast Wyoming. Reasons for the...

  15. SEXUAL DIFFERENCES IN THE ECOLOGY AND HABITAT SELECTION OF WESTERN TOADS (BUFO BOREAS IN NORTHEASTERN OREGON

    Directory of Open Access Journals (Sweden)

    EVELYN L. BULL

    2006-09-01

    Full Text Available Several species of toads (family Bufonidae, including the Western Toad (Bufo boreas have declined in thewestern United States. Information on toad ecology and habitat use is essential to determine potential causes for populationdeclines, as is the potential relationship between this information and disturbance events. Aspects of western toad survival,mortality, movements, habitat selection, and diet were investigated at five study areas in northeastern Oregon duringsummers of 2002-2005. Of 100 radio-tagged toads monitored for one summer during these years, 32% survived untilSeptember, 29% were killed by predators, 10% died of other causes, and 29% were missing or had lost transmitters. Atfour study areas sampled in 2005, 24% of 37 males and 44% of 32 females sampled during the breeding season, and threedead male toads found after the breeding season tested positive for Batrachochytrium dendrobatidis. Females traveledsignificantly farther than males, and the maximum distances traveled by female and male toads were 6230 m and 3870 m,respectively. Toads with transmitters selected habitats: (1 with little or no canopy; (2 on south-facing slopes; (3 nearwater; and (4 with high densities of potential refugia (e.g., burrows, rocks, logs. Males were more closely associated withwater than females. Twenty-six toads overwintered in rodent burrows (38%, under large rocks (27%, under logs or rootwads (19%, and under banks adjacent to streams or a lake (15%. Diet consisted of 82% ants (Formicidae, 13% beetles(Coleoptera, and <1% in 8 additional orders of insects with no differences detected between male and female toads.Disturbance events, such as wildfire, can influence refugia and prey of toads, and climatic conditions may influence a toad’ssusceptibility to B. dendrobatidis.

  16. Seasonal and daily plasma corticosterone rhythms in American toads, Bufo americanus

    International Nuclear Information System (INIS)

    Concentrations of corticosterone were measured in the plasma of American toads, Bufo americanus, on a seasonal basis using a radioimmunoassay technique. Two populations of toads, maintained under different light conditions, were monitored to observe the effects of photoperiod on the seasonal rhythm of plasma corticosterone. Under a natural photoperiod toads demonstrated a rhythm consisting of a spring peak and a fall peak in corticosterone concentration. Toads maintained under a 12L:12D photoperiod all year round demonstrated a similar rhythm with peaks in the spring and fall. This suggests that an endogenous (circannual) rhythm of corticosterone may be playing an important role in the seasonal change of overt behavior and physiology of Bufo americanus. A daily rhythm of corticosterone was also detected in toads when blood samples were taken every 4 hr. When compared to a previously published circadian rhythm study of locomotor activity, the surge in corticosterone concentration for the day occurred at 1730 just prior to the peak in locomotor activity

  17. Localization of water channels in the skin of two species of desert toads, Anaxyrus (Bufo) punctatus and Incilius (Bufo) alvarius.

    Science.gov (United States)

    Shibata, Yuki; Takeuchi, Hiro-Aki; Hasegawa, Takahiro; Suzuki, Masakazu; Tanaka, Shigeyasu; Hillyard, Stanley D; Nagai, Takatoshi

    2011-09-01

    Anuran amphibians obtain water by osmosis across their ventral skin. A specialized region in the pelvic skin of semiterrestrial species, termed the seat patch, contains aquaporins (AQPs) that become inserted into the apical plasma membrane of the epidermis following stimulation by arginine vasotocin (AVT) to facilitate rehydration. Two AVT-stimulated AQPs, AQP-h2 and AQP-h3, have been identified in the epidermis of seat patch skin of the Japanese tree frog, Hyla japonica, and show a high degree of homology with those of bufonid species. We used antibodies raised against AQP-h2 and AQP-h3 to characterize the expression of homologous AQPs in the skin of two species of toads that inhabit arid desert regions of southwestern North America. Western blot analysis of proteins gave positive results for AQP-h2-like proteins in the pelvic skin and also the urinary bladder of Anaxyrus (Bufo) punctatus while AQP-h3-like proteins were found in extracts from the pelvic skin and the more anterior ventral skin, but not the urinary bladder. Immunohistochemical observations showed both AQP-h2- and AQP-h3-like proteins were present in the apical membrane of skin from the pelvic skin of hydrated and dehydrated A. punctatus. Further stimulation by AVT or isoproterenol treatment of living toads was not evident. In contrast, skin from hydrated Incilius (Bufo) alvarius showed very weak labeling of AQP-h2- and AQP-h3-like proteins and labeling turned intense following stimulation by AVT. These results are similar to those of tree frogs and toads that occupy mesic habitats and suggest this pattern of AQP expression is the result of phylogenetic factors shared by hylid and bufonid anurans. PMID:21882955

  18. Hormonal priming, induction of ovulation and in-vitro fertilization of the endangered Wyoming toad (Bufo baxteri)

    OpenAIRE

    Seratt Jessica; Browne Robert K; Vance Carrie; Kouba Andrew

    2006-01-01

    Abstract The endangered Wyoming toad (Bufo baxteri) is the subject of an extensive captive breeding and reintroduction program. Wyoming toads in captivity rarely ovulate spontaneously and hormonal induction is used to ovulate females or to stimulate spermiation in males. With hormonal induction, ovulation is unreliable and egg numbers are low. The sequential administration of anovulatory doses of hormones (priming) has increased egg numbers and quality in both anurans and fish. Consequently, ...

  19. HABITAT PATCH OCCUPANCY BY THE RED-SPOTTED TOAD (BUFO PUNCTATUS) IN A NATURALLY FRAGMENTED, DESERT LANDSCAPE

    Science.gov (United States)

    Amphibians are often thought to have a metapopulation structure, which may render them vulnerable to habitat fragmentation. The red-spotted toad (Bufo panctatus) in the southwestern USA and Mexico commonly inhabits wetlands that have become much smaller and fewer since the la...

  20. Screening breeding sites of the common toad (Bufo bufo) in England and Wales for evidence of endocrine disrupting activity.

    Science.gov (United States)

    Pickford, Daniel B; Jones, Alexandra; Velez-Pelez, Alejandra; Iguchi, Taisen; Mitsui, Naoko; Tooi, Osamu

    2015-07-01

    Anuran amphibians are often present in agricultural landscapes and may therefore be exposed to chemicals in surface waters used for breeding. We used passive accumulation devices (SPMD and POCIS) to sample contaminants from nine breeding sites of the Common toad (Bufo bufo) across England and Wales, measuring endocrine activity of the extracts in a recombinant yeast androgen screen (YAS) and yeast estrogen screen (YES) and an in vitro vitellogenin induction screen in primary culture of Xenopus laevis hepatocytes. We also assessed hatching, growth, survival, and development in caged larvae in situ, and sampled metamorphs for gonadal histopathology. None of the SPMD extracts exhibited estrogen receptor or androgen receptor agonist activity, while POCIS extracts from two sites in west-central England exhibited concentration-dependent androgenic activity in the YAS. Three sites exhibited significant estrogenic activity in both the YES and the Xenopus hepatocyte. Hatching rates varied widely among sites, but there was no consistent correlation between hatching rate and intensity of agricultural activity, predicted concentrations of agrochemicals, or endocrine activity measured in YES/YAS assays. While a small number of intersex individuals were observed, their incidence could not be associated with predicted pesticide exposure or endocrine activitity measured in the in vitro screens. There were no significant differences in sex ratio, as determined by gonadal histomorphology among the study sites, and no significant correlation was observed between proportion of males and predicted exposure to agrochemicals. However, a negative correlation did become apparent in later sampling periods between proportion of males and estrogenic activity of the POCIS sample, as measured in the YES. Our results suggest that larval and adult amphibians may be exposed to endocrine disrupting chemicals in breeding ponds, albeit at low concentrations, and that chemical contaminants other than plant protection products may contribute to endocrine activity of surface waters in the agricultural landscape. PMID:25817886

  1. Body size, nuptial pad size and hormone levels: potential non-destructive biomarkers of reproductive health in wild toads (Bufo bufo).

    Science.gov (United States)

    Orton, Frances; Baynes, Alice; Clare, Frances; Duffus, Amanda L J; Larroze, Severine; Scholze, Martin; Garner, Trenton W J

    2014-09-01

    Amphibians are declining and fertility/fecundity are major drivers of population stability. The development of non-destructive methods to assess reproductive health are needed as destructive measures are fundamentally at odds with conservation goals for declining species. We investigated the utility of body size, nuptial pad size and forelimb width as non-destructive biomarkers of internal reproductive physiology, by analysing correlations with commonly used destructive methods in adult male toads (Bufo bufo) from a low human impact and a high human impact site. Principal component analyses revealed that size was the most important variable for explaining inter-individual differences in other measured endpoints, both non-destructive and destructive, except for hormone levels and nuptial pad, which were independent of size. Toads from the LI and the HI site differed in almost all of the measured endpoints; this was largely driven by the significantly smaller size of toads from the HI site. Correlational analyses within sites revealed that size was correlated with several reproductive endpoints in toads from the HI site but not the LI site, indicating a possible limiting effect of size on reproductive physiology. Intersex was observed in 33% of toads from the HI site and incidence was not related to any other measured endpoint. In conclusion, we provide evidence that size is associated with reproductive physiology and that nuptial pad/hormone levels have potential as additional markers due to their independence from size. We also show that human activities can have a negative effect on reproductive physiology of the common toad. PMID:24935780

  2. Chloride transport in toad skin (Bufo viridis). The effect of salt adaptation

    DEFF Research Database (Denmark)

    Katz, U; Larsen, Erik Hviid

    1984-01-01

    The steady-state Cl- current across the skin of Bufo viridis adapted to tap water was found to be rectified. In skins bathed with NaCl Ringer on both sides, a large outward current, carried by influx of Cl-, was observed at a clamping voltage (V) of less than -50 mV (outside of the skin negative). for V = -50 mV the transepithelial Cl- conductance calculated from isotope flux measurements was 2.5 +/- 0.3 mS cm-2, N = 10. When the skin was clamped at + 50 mV the net flux of Cl- was reversed, but Cl- conductance was only 0.3 +/- 0.1 mScm-2. Flux ratio analysis indicated that the potential-activated Cl- conductance carries Cl- ions by way of passive transport. With NaCl Ringer bathing the outer surface of the skin the spontaneous potential was about -30 mV. At this potential the Cl- conductance of the skin was about half of its maximum value. The time course of Cl- current activation following a fast, stepwise change of V from 50 mV to a potential below O mV showed an initial delay of a few seconds, and proceeded with a halftime (T 1/2) which varied as a bell-shaped function of V. The maximum T 1/2 was about 100 s for V = -10 mV in skins exposed to KCl Ringer on the outside. Following adaptation of the toads to a 250 mM-NaCl solution, the fully activated Cl- conductance of the skin was greatly reduced, and the conductance-voltage curve was shifted to the left along the voltage-axis. With NaCl Ringer on the outside the spontaneous potential was about -20 mV, and Cl- conductance activation was possible only outside the physiological range of potentials. The time constant of Cl- conductance activation from closed to fully activated state was more than doubled following salt adaptation of the toads. The active inward Cl- flux disappeared in skins of toads adapted to a 250 mM-NaCl solution, and apparent leakage conductance was reduced. Application of the phosphodiesterase inhibitor 3-isobutyl-1-methyl-xanthine to skin of fully salt-adapted toads increased the transepithelial Cl- conductance, and the time courses of voltage clamp currents became more like those of water-adapted toads. Apparent leakage conductance was increased.(ABSTRACT TRUNCATED AT 400 WORDS)

  3. Histochemical and structural characterization of egg extra-cellular matrix in bufonid toads, Bufo bufo and Bufotes balearicus: molecular diversity versus morphological uniformity.

    Science.gov (United States)

    Mentino, Donatella; Mastrodonato, Maria; Rossi, Roberta; Scillitani, Giovanni

    2014-11-01

    The extra-cellular matrix of fertilized eggs in the bufonid toads Bufo bufo and Bufotes balearicus was studied to clear the relationships between structural and molecular diversity. Histochemical (PAS, AB pH 2.5 and pH 1.0, Beta-elimination PAS) and lectin-histochemical (Con A, WGA, Succinyl-WGA, PNA, RCA-1, DBA, SBA, AAA, UEA-I, LTA) techniques were used and the observations were made under light and electron microscopy. Both species present a fertilization envelope (FE) and two jelly layers (J1 and J2). The fibers of J2 are shared among the eggs of a clutch in a jelly ribbon. The FE of both species presents neutral glycoproteins, mostly N-linked. In B. bufo there are also residuals of mannose and/or glucose and N-acetylglucosamine. In the FE fibers run parallel to egg's surface or are in bundles or looser hanks with no clear orientation. The J1 layer of both species presents sialosulfoglycoproteins, mostly O-linked, with lactosaminylated, galactosaminylated, glycosaminylated, and fucosylated residuals. A lower amount of galactosaminylated residuals is observed in B. balearicus in respect to B. bufo, whereas the opposite is seen in the amount of fucosylated residuals. The J2 layer is similar in composition to J1 but in B. balearicus there are no glucosaminylated residuals. J layers present fibers and granules that reduce towards J2 . Several microorganisms, in particular blue algae, are observed in the J2 layer of both species. In respect to other species, B. bufo and B. balearicus have a lower number of jelly layers, but a comparable number of glycan types. PMID:25091902

  4. Multi-Level Effects of Low Dose Rate Ionizing Radiation on Southern Toad, Anaxyrus [Bufo] terrestris

    Science.gov (United States)

    Stark, Karolina; Scott, David E.; Tsyusko, Olga; Coughlin, Daniel P.; Hinton, Thomas G.

    2015-01-01

    Despite their potential vulnerability to contaminants from exposure at multiple life stages, amphibians are one of the least studied groups of vertebrates in ecotoxicology, and research on radiation effects in amphibians is scarce. We used multiple endpoints to assess the radiosensitivity of the southern toad (Anaxyrus [Bufo] terrestris) during its pre-terrestrial stages of development –embryonic, larval, and metamorphic. Toads were exposed, from several hours after oviposition through metamorphosis (up to 77 days later), to four low dose rates of 137Cs at 0.13, 2.4, 21, and 222 mGy d-1, resulting in total doses up to 15.8 Gy. Radiation treatments did not affect hatching success of embryos, larval survival, or the length of the larval period. The individual family variation in hatching success of embryos was larger than the radiation response. In contrast, newly metamorphosed individuals from the higher dose-rate treatments had higher mass and mass/length body indices, a measure which may relate to higher post-metamorphic survival. The increased mass and index at higher dose rates may indicate that the chronic, low dose rate radiation exposures triggered secondary responses. Additionally, the increases in growth were linked to a decrease in DNA damage (as measured by the Comet Assay) in red blood cells at a dose rate of 21 mGy d-1 and a total dose of 1.1 Gy. In conclusion, the complex effects of low dose rates of ionizing radiation may trigger growth and cellular repair mechanisms in amphibian larvae. PMID:25927361

  5. Toads

    Science.gov (United States)

    Ms. B

    2011-04-06

    What are some characteristics of toads? Characterizing toads so that students can complete fact books and a final project of constructing a toad. First you will use: Toad Graphic Organizer Then you will use: All About Toads AND Toad Facts Then you will use: Toads vs. Frogs Then: Life Cycle of a Toad Then use: What do toads eat? Now we will watch a video on toads! Toad Video on National Geographic ...

  6. Inhibition of Batrachochytrium dendrobatidis Caused by Bacteria Isolated from the Skin of Boreal Toads, Anaxyrus (Bufo) boreas boreas, from Grand Teton National Park, Wyoming, USA

    OpenAIRE

    Park, Shawna T.; Collingwood, Amanda M.; Sophie St-Hilaire; Sheridan, Peter P.

    2014-01-01

    The chytrid fungus Batrachochytrium dendrobatidis is a significant cause of the worldwide decline in amphibian populations; however, various amphibian species are capable of coexisting with B. dendrobatidis. Among them are boreal toads (Anaxyrus (Bufo) boreas boreas) located in Grand Teton National Park (GTNP) in Wyoming, USA. The purpose of this study was to identify cultivable bacterial isolates from the skin microbiota of boreal toads from GTNP and determine if they were capable of inhibit...

  7. Hormonal priming, induction of ovulation and in-vitro fertilization of the endangered Wyoming toad (Bufo baxteri

    Directory of Open Access Journals (Sweden)

    Seratt Jessica

    2006-06-01

    Full Text Available Abstract The endangered Wyoming toad (Bufo baxteri is the subject of an extensive captive breeding and reintroduction program. Wyoming toads in captivity rarely ovulate spontaneously and hormonal induction is used to ovulate females or to stimulate spermiation in males. With hormonal induction, ovulation is unreliable and egg numbers are low. The sequential administration of anovulatory doses of hormones (priming has increased egg numbers and quality in both anurans and fish. Consequently, we tested the efficacy of a combination of human Chorionic Gonadotrophin (hCG and Luteinizing Hormone Releasing Hormone analogue (LHRHa administered as one dose, or two or three sequential doses to Bufo baxteri on egg numbers, fertilization and early embryo development. Spawning toads deposited eggs into Simplified Amphibian Ringers (SAR solution to enable controlled in-vitro fertilization (IVF with sperm from hormonally induced male toads. Unprimed females receiving a single mixed normally ovulatory dose of 500 IU hCG plus 4 micrograms of LHRHa produced no eggs. Whereas females primed with this dose and an anovulatory dose (100 IU hCG and 0.8 micrograms of LHRHa of the same hormones, or primed only with an anovulatory dose, spawned after then receiving an ovulatory dose. Higher total egg numbers were produced with two primings than with one priming. Moreover, two primings produced significantly more eggs from each individual female than one priming. The cleavage rate of eggs was not found to differ between one or two primings. Nevertheless, embryo development with eggs from two primings gave a significantly greater percentage neurulation and swim-up than those from one priming. Of the male toads receiving a single dose of 300 IU hCG, 80% produced spermic urine with the greatest sperm concentration 7 hours post-administration (PA. However, peak sperm motility (95% was achieved at 5 hours PA and remained relatively constant until declining 20 hours PA. In conclusion, Bufo baxteri egg numbers and quality benefited from sequential priming with LHRHa and hCG whereas spermic urine for IVF was produced from males with a single dose of hCG. The power of assisted reproduction technology in the conservation of endangered amphibians is shown by the release of nearly 2000 tadpoles produced by IVF during this study.

  8. Interactive effects of maternal and environmental exposure to coal combustion wastes decrease survival of larval southern toads (Bufo terrestris)

    International Nuclear Information System (INIS)

    We conducted a mesocosm study to assess the individual and interactive effects of previous maternal exposure and larval exposure to trace element-laden sediments on southern toads (Bufo terrestris). Previous maternal exposure to coal combustion wastes (CCW) reduced larval survival to metamorphosis up to 57% compared to larvae of unexposed females. Larvae reared on CCW accumulated significant concentrations of trace elements resulting in extended larval periods, reduced growth rates, and reduced mass at metamorphosis. However, the effects were dependent on age of sediments, suggesting the effects of contaminants from CCW may be partially ameliorated over time through the reduced bioavailability of trace elements in aged CCW. Most importantly, maternal exposure to contaminants coupled with larval exposure to fresh CCW interacted to reduce survival to metamorphosis by 85% compared to reference conditions. Our study yields further evidence that disposal of CCW in aquatic basins potentially creates ecological traps for some amphibian populations. - Highlights: ? The interaction of maternal exposure and larval exposure to CCW reduced survival. ? Previous maternal exposure to CCW had a latent effect on survival to metamorphosis. ? Larval southern toads exposed to CCW experienced prolonged larval periods. ? Larval southern toads exposed to CCW had reduced growth rates. ? Larval southern toads exposed to CCW had reduced mass at metamorphosis. - Maternal and environmephosis. - Maternal and environmental exposure to coal combustion wastes interact to decrease survival in larval amphibians.

  9. Diet of southern toads (Bufo terrestris) in loblolly pine (Pinus taeda) stands subject to coarse woody debris manipulations.

    Energy Technology Data Exchange (ETDEWEB)

    Moseley, Kurtis R.; Steven B. Castleberry; James L. Hanula; Mark Ford.

    2005-04-01

    ABSTRACT In the southeastern United States, coarse woody debris (CWD) typically harbors high densities of invertebrates. However, its importance as a foraging substrate for southeastern amphibians is relatively unknown. We examined effects of CWD manipulations on diet composition of southern toads (Bufo terrestris) in upland loblolly pine (Pinus taeda) stands in the Coastal Plain of South Carolina. Twelve 9.3-ha plots were assigned one of the following treatments: removal- all CWD _10 cm in diameter and _60 cm long removed; downed- five-fold increase in volume of down CWD; and unmanipulated control stands. We collected southern toads _4 cm snout-vent length (SVL) during 14 d sampling periods in June and October 2002, June 2003 and during a 28 d sampling period in April 2003. We collected 80, 36 and 35 southern toads in control, downed and removal treatments, respectively. We found no difference in relative abundance or frequency of invertebrate groups consumed among treatments (P.0.05). Average body weight (g), SVL (cm) and stomach content weight (g wet) of individuals also were similar among treatments (P . 0.05). The role of CWD as a foraging substrate for southern toads in loblolly pine stands of the southeastern Coastal Plain may be negligible, at least in the early stages of decay.

  10. Evaluation of the Genotoxicity of Chlorpyrifos in Common Indus Valley Toad, Bufo stomaticus Using Alkaline Single-Cell Gel Electrophoresis (Comet) Assay

    OpenAIRE

    Muhammad Ismail; Qaiser Mahmood Khan; Rahat Ali; Tayyaba Ali; Ameena Mobeen

    2014-01-01

    Chlorpyrifos is a commonly used pesticide of organophosphate group, which causes toxicological effects in non-target organisms especially fish and frogs. In the present study, the genotoxicity of sublethal concentrations of chlorpyrifos was observed in the erythrocytes of common Indus valley toad, Bufo stomaticus, using the Alkaline Single-Cell Gel Electrophoresis (Comet) assay. In the first step, acute toxicity of chlorpyrifos was evaluated by exposing the tadpoles to ...

  11. Relation between chloride exchange diffusion and a conductive chloride pathway across the isolated skin of the toad (Bufo bufo)

    DEFF Research Database (Denmark)

    Kristensen, P; Larsen, Erik Hviid

    1978-01-01

    Substitution of chloride in the outside bathing medium of the toad skin with bromide, iodide, nitrate and sulphate leads to a reduction in the apparent exchange diffusion of chloride across this tissue, and also to a reduction of the chloride current recorded during hyperpolarization. A series of inhibitors (thiocyanate, furosemide, phloretin, and acetazolamide) also affects chloride exchange diffusion, hyperpolarization current as well as chloride influx during hyperpolarization. Although in some cases, effects on the short circuit current were also observed none of the effects on chloride transport systems could be explained as secondary effects due to a primary interaction with the sodium transport mechanisms. A correlation was found between the clamping current recorded during hyperpolarization and the efflux of chloride under short circuit conditions with chloride Ringer's on both sides. On the basis of these findings, and the results reported in the previous paper (Hviid Larsen and Kristensen 1977) it is considered probable that the membrane molecules responsible to chloride exchange diffusion under short circuit conditions, are rearranged under the influence of a hyperpolarizing clamping voltage, thereby forming channels allowing charge transferring transport of chloride.

  12. Spatial and temporal ecology of oak toads (Bufo quercicus) on a Florida landscape.

    Energy Technology Data Exchange (ETDEWEB)

    Greenberg, Cathryn, H.; Tanner, George, W.

    2005-12-01

    ABSTRACT: We used data from 10 years of continuous, concurrent monitoring of oak toads at eight isolated, ephemeral ponds in Florida longleaf pine-wiregrass uplands to address: (1) did weather variables affect movement patterns of oak toads?; (2) did pond hydrology and the condition of surrounding uplands affect pond selection by adults or juvenile recruitment?; (3) were population trends evident?; and (4) did a classical metapopulation model best represent their population ecology? Of 4076 oak toads captured, 92.2% were adults. Substantial (n _ 30 exiting juveniles) recruitment occurred only three times (once each at three ponds during two years). Males outnumbered females (average for all years 2.3:1). Most captures occurred during May–September. Adult captures during June–August increased with heavier rainfall but were not influenced by the durations of preceding dry periods. Movement patterns of metamorphs suggested that oak toads emigrated when moisture conditions become favorable. Pond use by adults was correlated with maximum change in pond depth (May–September). Juvenile recruitment was negatively correlated with minimum pond depth and the number of weeks since a pond was last dry, and positively correlated with the maximum number of weeks a pond held water continuously. The number of breeding adults and juvenile recruitment were highest at ponds within the hardwood-invaded upland matrix. The direction of most immigrations and emigrations was nonrandom, but movement occurred from all directions, and the mean direction of pond entry and exit did not always correspond. A total of 21.1% of individuals was recaptured; 13.3% of first captures were recaptured during the same year, and 7.7% during a subsequent year. Only 1.9% of captured oak toads moved among ponds, mostly within a distance of 132 m. We did not detect adult population trends over the 10- yr studied. Presence or absence at ponds in any given year was a poor indicator of overall use. We saw little evidence of local extinction or ‘‘rescue,’’ but were unable to determine whether juveniles returned to natal ponds or colonized new ponds for breeding as adults. Oak toad conservation can best be ensured by maintaining multiple ponds within a landscape to increase the probability of recruitment within the landscape neighborhood during at least some years and at some ponds, and to increase the likelihood of interpond movement.

  13. Use of lidocaine, propranolol, amiodarone, and verapamil in toad envenoming (genus bufo) in dogs

    OpenAIRE

    Sakate, M.; Lucas Oliveira, P. C.

    2001-01-01

    Toad envenoming in dogs can cause death by cardiac fibrilation (CVF). Traditional therapy consists mainly of atropine and propranolol, the last one used to prevent the CVF, that is preceded by negative ventricular deflections (NVDs) in the QRS complex of the electrocardiogram. This study intended to verify, comparatively, the lidocaine, propranolol, amiodarone, and verapamil abilities to prevent CVF in experimentally envenomed dogs. Thirty-six dogs were divided into 6 groups (GL, GP, GA, GV, ...

  14. Ventilatory behaviors of the toad Bufo marinus revealed by coherence analysis

    Directory of Open Access Journals (Sweden)

    Coelho F. C.

    2003-01-01

    Full Text Available Breathing in amphibians is a remarkably complex behavior consisting of irregular breaths that may be taken singly or in bouts that are used to deflate and inflate the lungs. The valves at the two outlets of the buccal cavity (nares and glottis need to be finely controlled throughout the bout for the expression of these complex respiratory behaviors. In this study, we use a technique based on the calculation of the coherence spectra between respiratory variables (buccal pressure; narial airflow; and lung pressure. Coherence was also used to quantify the effects of chemoreceptor and pulmonary mechanoreceptor input on narial and glottal valve behavior on normoxic, hypoxic, and hypercapnic toads with both intact and bilaterally sectioned pulmonary vagi. We found a significant reduction in narial coherence in hypoxic vagotomized toads indicating that pulmonary mechanoreceptor feedback modulates narial opening duration. An unexpectedly high coherence between Pl and Pb during non-respiratory buccal oscillations in hypercapnic toads indicated more forceful use of the buccal pump. We concluded that the coherence function reveals behaviors that are not apparent through visual inspection of ventilatory time series.

  15. A contribution to the knowledge of the trophic spectrum of the Common toad (Bufo bufo L., 1758 (Amphibia: Anura from Bulgaria

    Directory of Open Access Journals (Sweden)

    Petar Boyadzhiev

    2009-07-01

    Full Text Available During our study we identified 500 prey items in 20 prey categories in the trophic spectrum of Bufo bufo with average number of prey items per stomach 25.00. The most important prey taxon is Formicidae (70.20%, followed by Coleoptera (especially Carabidae – 11.40%, as well as non-insect invertebrates (Isopoda, Gastropoda, Arachnida which also play significant role. The estimated trophic niche breadth is low – 1.96.

  16. Use of lidocaine, propranolol, amiodarone, and verapamil in toad envenoming (genus bufo) in dogs

    Scientific Electronic Library Online (English)

    M., SAKATE; P. C. LUCAS DE, OLIVEIRA.

    2001-12-01

    Full Text Available Toad envenoming in dogs can cause death by cardiac fibrilation (CVF). Traditional therapy consists mainly of atropine and propranolol, the last one used to prevent the CVF, that is preceded by negative ventricular deflections (NVDs) in the QRS complex of the electrocardiogram. This study intended to [...] verify, comparatively, the lidocaine, propranolol, amiodarone, and verapamil abilities to prevent CVF in experimentally envenomed dogs. Thirty-six dogs were divided into 6 groups (GL, GP, GA, GV, GST, and GSV) with n=6; the dogs were submitted to volatile anaesthesia. The animals of the groups GL, GP, GA, and GV received 0.38g of toad venom through oro-gastric catheter and were treated with the following drugs respectively: lidocaine (4mg/Kg), propranolol (0.1mg/Kg), amiodarone (8mg/Kg), and verapamil (2mg/Kg). These drugs were repeated if NVDs reappeared with cardiac frequency >150, GST was not treated and GSV was just anaesthetized. The following results were obtained: GL, NVDs present in 4 animals, 100% recuperation with 3.66 doses/animal; GP, NVDs present in 2 animals, 100% recuperation with 1.66 dose/animal, with bradycardia at the anaesthetic return; GA, NVDs present in 3 animals, 33.33% recuperation with 1.5 dose/animal; GV, NVDs present in 4 animals, 100% recuperation with 2.16 doses/animal; GST, NVD present in 6 animals, 100% death and GSV, NVDs absent, 100% recuperation. As a conclusion, the anaesthetic proceedings used, did not cause NVDs, the envenoming that was not treated was lethal, and among the antiarrhythmics drugs used, verapamil was the most efficient, as it did not cause any serious bradycardia at the anaesthetic return and did not require repeated administrations. For lidocaine, it was efficient but required various administrations; amiodarone could not prevent the death of 4 animals; propranolol was efficient in relation to NVDs control, but caused serious bradycardia at the anaesthetic return.

  17. Use of lidocaine, propranolol, amiodarone, and verapamil in toad envenoming (genus bufo in dogs

    Directory of Open Access Journals (Sweden)

    M. SAKATE

    2001-12-01

    Full Text Available Toad envenoming in dogs can cause death by cardiac fibrilation (CVF. Traditional therapy consists mainly of atropine and propranolol, the last one used to prevent the CVF, that is preceded by negative ventricular deflections (NVDs in the QRS complex of the electrocardiogram. This study intended to verify, comparatively, the lidocaine, propranolol, amiodarone, and verapamil abilities to prevent CVF in experimentally envenomed dogs. Thirty-six dogs were divided into 6 groups (GL, GP, GA, GV, GST, and GSV with n=6; the dogs were submitted to volatile anaesthesia. The animals of the groups GL, GP, GA, and GV received 0.38g of toad venom through oro-gastric catheter and were treated with the following drugs respectively: lidocaine (4mg/Kg, propranolol (0.1mg/Kg, amiodarone (8mg/Kg, and verapamil (2mg/Kg. These drugs were repeated if NVDs reappeared with cardiac frequency >150, GST was not treated and GSV was just anaesthetized. The following results were obtained: GL, NVDs present in 4 animals, 100% recuperation with 3.66 doses/animal; GP, NVDs present in 2 animals, 100% recuperation with 1.66 dose/animal, with bradycardia at the anaesthetic return; GA, NVDs present in 3 animals, 33.33% recuperation with 1.5 dose/animal; GV, NVDs present in 4 animals, 100% recuperation with 2.16 doses/animal; GST, NVD present in 6 animals, 100% death and GSV, NVDs absent, 100% recuperation. As a conclusion, the anaesthetic proceedings used, did not cause NVDs, the envenoming that was not treated was lethal, and among the antiarrhythmics drugs used, verapamil was the most efficient, as it did not cause any serious bradycardia at the anaesthetic return and did not require repeated administrations. For lidocaine, it was efficient but required various administrations; amiodarone could not prevent the death of 4 animals; propranolol was efficient in relation to NVDs control, but caused serious bradycardia at the anaesthetic return.

  18. Oxygen-sensitive regulatory volume increase and Na transport in red blood cells from the cane toad, Bufo marinus.

    Science.gov (United States)

    Kristensen, Karina; Koldkjaer, Pia; Berenbrink, Michael; Wang, Tobias

    2007-07-01

    The red blood cells (RBCs) of cane toad, Bufo marinus, are only partially saturated with oxygen in most of the circulation due to cardiac shunts that cause desaturation of arterial blood. The present study examines the oxygen dependency of RBC ouabain-insensitive unidirectional Na transport, using 22Na, in control cells and in cells exposed to hyperosmotic shrinkage or the beta-adrenergic agonist isoproterenol. Deoxygenation per se induced a slow, but significant Na influx, which was paralleled by a slow increase in RBC volume. Hyperosmotic shrinkage by a calculated 25% activated a robust Na influx that in the first 30 min had a strong PO2 dependency with maximal activation at low PO2 values and a P50 of approximately 5.5 kPa. This activation was completely abolished by the Na/H exchanger (NHE) inhibitor EIPA (10(-4) mol l(-1)). Hyperosmotic shrinkage is particularly interesting in B. marinus as it withstands considerable elevation in extracellular osmolarity following dehydration. Parallel studies showed that deoxygenated B. marinus RBCs had a much faster regulatory volume increase (RVI) response than air-equilibrated RBCs, reflecting the difference in magnitude of Na influxes at the two PO2 values. The extent of RVI ( approximately 60%) after 90 min, however, was similar under the two conditions, reflecting a more prolonged elevation of the shrinkage-induced Na influx in air-equilibrated RBCs. There were no significant differences in the ability to perform RVI between whole blood cells at a PCO2 of 1 and 3 kPa or washed RBCs, and 10(-4) mol l(-1) amiloride reduced the RVI under all conditions, whereas 10(-5) mol l(-1) bumetanide had no effect. Isoproterenol (10(-5) mol l(-1)) induced a significant and prolonged increase in an EIPA-sensitive and bumetanide-insensitive Na influx at low PO2 under iso-osmotic conditions, whilst there was no stimulation by isoproterenol for up to 45 min in air-equilibrated RBCs. The prolonged beta-adrenergic activation of the Na influx at low PO2 is distinctly different from the rapid and transient stimulation in teleost RBCs, suggesting significant differences in the signal transduction pathways leading to transporter activation between vertebrate groups. PMID:17575034

  19. Exposure of toad embryos and larvae to pesticides. Use of nuclear technique to determine their effect on the reproduction, survival and potential risk to Bufo arenarum populations

    International Nuclear Information System (INIS)

    Application of pesticides is currently the most common method used to control agricultural pests. However, undesired effects on non-target organisms and pollution of the soil, air and water are frequent consequences. Amphibians are good bioindicators of the presence of contaminants in the environment, because they are semi-aquatic animals located at the top of the food chain. In many parts of the world, amphibian populations are declining, and many reasons have been suggested for these losses. Although a link between widespread decline and pesticide residues has yet to be established, it is suspected that contamination of their breeding sites with pesticide residues has had a deleterious effect on the reproduction and development of amphibians. Recent experiments with a widely distributed toad, Bufo arenarum Hensel, in South America, particularly in Argentina, indicate that a variety of insecticides affects the fertilization process through the activation of an enzyme that degrades the source of second messengers and is involved in transducing the sperm signal to the oocyte. This harmful effect is not restricted to the fertilization process, since embryonic and larval development are also affected, producing severe morphological and behavioural abnormalities in embryos. Embryonic and larval development influence the timing of metamorphosis, the susceptibility to predation, survival in the terrestrial environment, and even the success of future reproduction, these beinsuccess of future reproduction, these being the most sensitive period of a toad's life. Evaluation of the pesticides in our region showed their presence in many of the potential breeding sites, confirming that they may influence the survival of toad populations. (author). 18 refs, 1 fig., 1 tab

  20. Biosynthesis of bufadienolides in toads. VI. Experiments with [1,2-3H]cholesterol, [21-14C]coprostanol, and 5 beta-[21-14 C]pregnanolone in the toad Bufo arenarum.

    Science.gov (United States)

    Garraffo, H M; Gros, E G

    1986-01-01

    [1,2-3H]Cholesterol, 5 beta-[21-14C]cholestan-3 beta-ol (coprostanol), and 3 beta-hydroxy-5 beta-[21-14C]pregnan-20-one were injected into intact Bufo arenarum toads. Arenobufagin, the main bufadienolide present in the venom of the mentioned toad, was isolated and purified by means of chromatographic procedures. The first two compounds, having an intact cholesterol side chain, were incorporated, at comparable levels, into the bufadienolide while the labeled pregnane derivative yielded non-radioactive arenobufagin. The above results support the hypothesis that cholesterol and those steroids having an intact cholesterol-type side chain are able to penetrate to the site of bufadienolide biosynthesis and are converted into bufadienolides by a still-unknown mechanism. On the other hand, those steroid derivatives bearing a degraded side chain, e.g., 20-keto-pregnanes, are not converted into bufadienolides because they are not incorporated into the bufadienolide-producing cells. PMID:3127947

  1. Helminth community structure of sympatric eastern American toad, Bufo americanus americanus, northern leopard frog, Rana pipiens, and blue-spotted salamander, Ambystoma laterale, from southeastern Wisconsin.

    Science.gov (United States)

    Bolek, Matthew G; Coggins, James R

    2003-08-01

    One-hundred twelve amphibians, including 51 blue-spotted salamanders, Ambystoma laterale, 30 eastern American toads, Bufo americanus americanus, and 31 northern leopard frogs, Rana pipiens, were collected during April-October 1996 from Waukesha County, Wisconsin and examined for helminth parasites. The helminth compound community of this amphibian assemblage consisted of at least 10 species: 9 in American toads, 8 in leopard frogs, and 3 in blue-spotted salamanders. American toads shared 7 species with leopard frogs, and 2 species occurred in all 3 host species. Although there was a high degree of helminth species overlap among these sympatric amphibians, statistically significant differences were found among host species and percent of indirect or direct-life cycle parasites of amphibian species individual component communities (chi2 = 1,015, P frogs had a higher relative abundance of larval cestodes, 71.3%, and larval and adult trematodes, 25.3%, than nematodes 3.4%. This is related to ecological differences in habitat and dietary preferences between these 2 anuran species. Helminth communities of blue-spotted salamanders were depauperate and were dominated by larval trematodes, 94%, and few nematodes, 6%. Low helminth species richness in this host species is related to this salamander's relatively small host body size, smaller gape size, lower vagility, and more fossorial habitat preference than the other 2 anuran species. Adult leopard frogs and toads had significantly higher mean helminth species richness than metamorphs, but there was no significant difference in mean helminth species richness among adult and metamorph blue-spotted salamanders. Considering adult helminths, the low species richness and low vagility of caudatans as compared with anurans suggest that local factors may be more important in structuring caudatan helminth communities of salamanders than of anuran hosts. Helminth species infecting salamanders may be more clumped in their geographic distribution as compared with anurans, and the role of other hosts and their parasites at the compound community level may be important in structuring helminth communities of salamanders. PMID:14533672

  2. The Brongersma's toad (Bufo brongersmai, Hoogmoed 1972): a summary of the new data on morphology, ecology, distribution and population dynamics

    OpenAIRE

    Seglie, Daniele; Delfino, Massimo

    2010-01-01

    Il rospo di Brongersma (Bufo brongersmai Hoogmoed, 1972) è stato oggetto negli ultimi anni di alcuni studi che hanno significativamente incrementato le conoscenze relative alla sua morfologia, ecologia, distribuzione e dinamica di popolazione. Sebbene esistano ancora opinioni contrastanti sulle sue relazioni filogenetiche, è ora conosciuta la morfologia dei principali elementi scheletrici e la struttura dei canti emessi nel periodo riproduttivo. E’ stata studiata la demografia e la modali...

  3. Toad poisoning in Laos.

    OpenAIRE

    Keomany, S; Mayxay, M; Souvannasing, P; Vilayhong, C; Stuart, BL; Srour, L; Newton, PN

    2007-01-01

    We describe two patients who developed severe illness after eating the skin and eggs of a toad, probably Bufo melanostictus Schneider, in southeastern Laos. One boy died, and one developed a digoxin toxicity-like syndrome with bradycardia and heart failure but survived. A telephone survey of 16 Lao provincial hospitals suggested that toad poisoning occurs in at least six provinces. That 93% of villagers in three villages in southeastern Laos were aware that toads are poisonous but that 51% ha...

  4. Expression pattern of glycoconjugates in the Bidderian and ovarian follicles of the Brazilian toad Bufo ictericus analyzed by lectin histochemistry Padrão de expressão de glicoconjugados nos folículos Bidderianos e ovarianos do sapo brasileiro Bufo ictericus, analisado por histoquímica de lectin

    Directory of Open Access Journals (Sweden)

    C. F. Farias

    2006-02-01

    Full Text Available The Bidder's organ and ovary of the Brazilian toad Bufo ictericus were studied by light microscopy, using hematoxylin-eosin (HE and periodic acid Schiff (PAS staining. The expression and distribution of carbohydrate moieties was analyzed by lectin histochemistry, using 8 lectins with different carbohydrate specificities: Ulex europaeus (UEA I, Lens culinaris (LCA, Erythrina cristagalli (ECA, Arachis hypogaea (PNA, Ricinus communis (RCA I, Aleuria aurantia (AAA, Triticum vulgaris (WGA, and Glycine maximum (SBA. The results showed that the Bidderian zona pellucida presented alpha-mannose, alpha-L-fucose, beta-D-galactose, N-acetyl-D-glucosamine, and alpha/beta-N-acetyl-galactosamine residues. The Bidderian follicular cells showed the presence of beta-D-galactose and N-acetyl-D-glucosamine. In the extracellular matrix, alpha-mannose and alpha/beta-N-acetyl-galactosamine residues were detected. The ovarian zona pellucida showed alpha-L-fucose, N-acetyl-D-glucosamine, alpha/beta-N-acetyl-galactosamine residues, and alpha-mannose and N-acetyl-D-glucosamine residues were detected in the follicular cells. Thus, the zona pellucida in both organs contains N-acetyl-D-glucosamine, and alpha/beta-N-acetyl-galactosamine residues. alpha-L-fucose residues were detected in the zona pellucida of both organs, using different lectins. Considering that beta-D-galactose residue was absent from ovary but present in the Bidder's organ, this sugar residue may play an important role in follicle development, blocking the Bidderian follicles and preventing further development of the Bidder's organ into a functional ovary.O órgão do Bidder e o ovário do sapo Bufo ictericus foram analisados por meio de microscopia de luz, utilizando a coloração pela hematoxilina-eosina (HE e o método do ácido periódico de Schiff (PAS. A expressão e a distribuição de carboidratos foram verificadas por meio da histoquímica com lectinas, tendo sido utilizadas 8 lectinas com diferentes especificidades para carboidratos (Ulex europaeus (UEA I, Lens culinaris (LCA, Erythrina cristagalli (ECA, Arachis hypogaea (PNA, Ricinus communis (RCA I, Aleuria aurantia (AAA, Triticum vulgaris (WGA e Glycine maximum (SBA. Os resultados mostraram que a zona pelúcida Bidderiana apresenta resíduos de alfa-mannose, alfa-L-fucose, beta-D-galactose, N-acetilDglicosamine e alfa/beta-N-acetil-galactosamina. As células foliculares Bidderianas mostraram a presença de beta-D-galactose e N-acetil-D-glicosamina. Na matriz de extracelular foram detectados resíduos de alfa-mannose e alfa/beta-N-acetil-galactosamina. Resíduos de alfa-L-fucose, N-acetyl-D-glicosamina e alfa/beta-N-acetil-galactosamina foram evidenciados na zona pelúcida ovariana, enquanto na célula folicular foi detectado o resíduo de alfa-mannose e de N-acetil-D-glicosamina. Assim, a zona pelúcida, em ambos os órgãos, contém resíduos de N-acetil-D-glicosamina e alfa/beta-N-acetil-galactosamina. O resíduo de alfa-L-fucose foi detectado na zona pelúcida de ambos os órgãos, mas utilizando-se diferentes lectinas. Considerando que o resíduo de alfa-D-galactose é ausente no ovário, mas presente no órgão de Bidder, a alfa-D-galactose pode ter um papel importante no controle do desenvolvimento folicular, bloqueando o desenvolvimento dos folículos Bidderianos e impedindo que o órgão de Bidder se transforme em um ovário funcional.

  5. Expression pattern of glycoconjugates in the Bidderian and ovarian follicles of the Brazilian toad Bufo ictericus analyzed by lectin histochemistry / Padrão de expressão de glicoconjugados nos folículos Bidderianos e ovarianos do sapo brasileiro Bufo ictericus, analisado por histoquímica de lectin

    Scientific Electronic Library Online (English)

    C. F., Farias; R. A., Azevedo; L., Brito-Gitirana.

    2006-02-01

    Full Text Available O órgão do Bidder e o ovário do sapo Bufo ictericus foram analisados por meio de microscopia de luz, utilizando a coloração pela hematoxilina-eosina (HE) e o método do ácido periódico de Schiff (PAS). A expressão e a distribuição de carboidratos foram verificadas por meio da histoquímica com lectina [...] s, tendo sido utilizadas 8 lectinas com diferentes especificidades para carboidratos (Ulex europaeus (UEA I), Lens culinaris (LCA), Erythrina cristagalli (ECA), Arachis hypogaea (PNA), Ricinus communis (RCA I), Aleuria aurantia (AAA), Triticum vulgaris (WGA) e Glycine maximum (SBA). Os resultados mostraram que a zona pelúcida Bidderiana apresenta resíduos de alfa-mannose, alfa-L-fucose, beta-D-galactose, N-acetilDglicosamine e alfa/beta-N-acetil-galactosamina. As células foliculares Bidderianas mostraram a presença de beta-D-galactose e N-acetil-D-glicosamina. Na matriz de extracelular foram detectados resíduos de alfa-mannose e alfa/beta-N-acetil-galactosamina. Resíduos de alfa-L-fucose, N-acetyl-D-glicosamina e alfa/beta-N-acetil-galactosamina foram evidenciados na zona pelúcida ovariana, enquanto na célula folicular foi detectado o resíduo de alfa-mannose e de N-acetil-D-glicosamina. Assim, a zona pelúcida, em ambos os órgãos, contém resíduos de N-acetil-D-glicosamina e alfa/beta-N-acetil-galactosamina. O resíduo de alfa-L-fucose foi detectado na zona pelúcida de ambos os órgãos, mas utilizando-se diferentes lectinas. Considerando que o resíduo de alfa-D-galactose é ausente no ovário, mas presente no órgão de Bidder, a alfa-D-galactose pode ter um papel importante no controle do desenvolvimento folicular, bloqueando o desenvolvimento dos folículos Bidderianos e impedindo que o órgão de Bidder se transforme em um ovário funcional. Abstract in english The Bidder's organ and ovary of the Brazilian toad Bufo ictericus were studied by light microscopy, using hematoxylin-eosin (HE) and periodic acid Schiff (PAS) staining. The expression and distribution of carbohydrate moieties was analyzed by lectin histochemistry, using 8 lectins with different car [...] bohydrate specificities: Ulex europaeus (UEA I), Lens culinaris (LCA), Erythrina cristagalli (ECA), Arachis hypogaea (PNA), Ricinus communis (RCA I), Aleuria aurantia (AAA), Triticum vulgaris (WGA), and Glycine maximum (SBA). The results showed that the Bidderian zona pellucida presented alpha-mannose, alpha-L-fucose, beta-D-galactose, N-acetyl-D-glucosamine, and alpha/beta-N-acetyl-galactosamine residues. The Bidderian follicular cells showed the presence of beta-D-galactose and N-acetyl-D-glucosamine. In the extracellular matrix, alpha-mannose and alpha/beta-N-acetyl-galactosamine residues were detected. The ovarian zona pellucida showed alpha-L-fucose, N-acetyl-D-glucosamine, alpha/beta-N-acetyl-galactosamine residues, and alpha-mannose and N-acetyl-D-glucosamine residues were detected in the follicular cells. Thus, the zona pellucida in both organs contains N-acetyl-D-glucosamine, and alpha/beta-N-acetyl-galactosamine residues. alpha-L-fucose residues were detected in the zona pellucida of both organs, using different lectins. Considering that beta-D-galactose residue was absent from ovary but present in the Bidder's organ, this sugar residue may play an important role in follicle development, blocking the Bidderian follicles and preventing further development of the Bidder's organ into a functional ovary.

  6. Determination of pesticide aerial drift and associated effects to the endangered Wyoming toad (Bufo baxteri) at Mortenson and Hutton National Wildlife Refuges and potential reintroduction sites

    US Fish and Wildlife Service, Department of the Interior — The endangered Wyoming toad is confined to Mortenson National Wildlife Refuge NWR in southeast Wyoming. Reasons for the decline of the toad are unknown, but it is...

  7. The Use of Swiss Albino Mice and Egyptian Toads (Bufo regularis) as Reliable Biological Test Animals for Screening Chemicals and Drugs Which Induce Leukaemia in Man. I: The Effect of Nizoral (Ketoconazole) on Leucocytes of Toads and Mice

    OpenAIRE

    M.M. El-Mofty; A. E. Essawy; M.H. Shwairebv; H.M. Abdel-Karim

    2000-01-01

    Nizoral (Ketoconazole) is an antifungal drug used for the treatment of systemic mycosis and mucocutaneous candidiasis. Administration of Nizoral into toads and mice induced pronounced alterations in leucocytes. Electron microscopical examination revealed that these alterations are leukaemic alterations and they are more or less similar to the criteria reported in human Leukaemia. The changes were all comparable to those observed after the administration of the carcinogenic chemical 7,12 dimet...

  8. The Use of Swiss Albino Mice and Egyptian Toads (Bufo regularis as Reliable Biological Test Animals for Screening Chemicals and Drugs Which Induce Leukaemia in Man. I: The Effect of Nizoral (Ketoconazole on Leucocytes of Toads and Mice

    Directory of Open Access Journals (Sweden)

    M.M. El-Mofty

    2000-01-01

    Full Text Available Nizoral (Ketoconazole is an antifungal drug used for the treatment of systemic mycosis and mucocutaneous candidiasis. Administration of Nizoral into toads and mice induced pronounced alterations in leucocytes. Electron microscopical examination revealed that these alterations are leukaemic alterations and they are more or less similar to the criteria reported in human Leukaemia. The changes were all comparable to those observed after the administration of the carcinogenic chemical 7,12 dimethylbenz (a anthracene.

  9. Biometrical Analyses of a Sicilian Green Toad, Bufo siculus (Stöck et al. 2008), Population Living in Sicily (Italy) / Análisis Biométricos del Sapo Verde Siciliano, Bufo siculus (Stöck et al. 2008), Población que Vive en Sicilia (Italia)

    Scientific Electronic Library Online (English)

    Mario, Lo Valvo; Gabriele, Giacalone.

    2013-06-01

    Full Text Available Se realizó un estudio morfométrico de la estructura del sapo verde siciliano de la Reserva Natural "Monte Pellegrino" (norte-oeste de Sicilia). Un total de 666 individuos (354 machos y 312 hembras) fueron capturados desde el año 2003 durante la época de reproducción. Se encontraron diferencias estad [...] ísticamente significativas entre los dos sexos, donde el peso corporal fue el mejor parámetro (hasta 92% de clasificación correcta), seguido por la longitud corporal (hasta 90% de clasificación correcta). El uso simultáneo de todos los caracteres examinados solo aumentó un 1% la probabilidad de una correcta discriminación del sexo. En comparación con la dimensión de otras poblaciones de sapos verdes estudiados por otros autores, el tamaño del cuerpo de esta población siciliana resulta elevado, similar a las poblaciones de Córcega y Cerdeña. Es posible que la gran dimensión de la población siciliana pueda deberse al bajo nivel de competencia con anfibios otras especies y/o a la ausencia de una latencia de invierno. Abstract in english Morphometry structure of Sicilian green toad from the Nature Reserve "Monte Pellegrino" (north-western Sicily) was studied. A total of 666 individuals (354 males and 312 females) were captured in 2003 during reproduction period. Meaningful differences have statistically emerged among the two sexes a [...] nd the body weight is the best parameter (up to 92% correct classification), followed by the length of the body (up to 90% correct classification). The simultaneous use of all the examined characters only increases of 1% the probability for correct discrimination of the sex. In comparison to the dimension of other green toad populations studied by other authors, the body size of this sicilian population results elevated, similar to that of Corsica and of Sardinia. It is possible that the high dimension of the Sicilian population is the result of low competition with other amphibians species and/or to the absence of a winter latency.

  10. The primary structure and carbohydrate specificity of a beta-galactosyl-binding lectin from toad (Bufo arenarum Hensel) ovary reveal closer similarities to the mammalian galectin-1 than to the galectin from the clawed frog Xenopus laevis.

    Science.gov (United States)

    Ahmed, H; Pohl, J; Fink, N E; Strobel, F; Vasta, G R

    1996-12-20

    The detailed characterization of a galectin from the toad (Bufo arenarum Hensel) ovary in its primary structure, carbohydrate specificity, and overall biochemical properties has provided novel information pertaining to structural and evolutionary aspects of the galectin family. The lectin consists of identical single-chain polypeptide subunits composed of 134 amino acids (calculated mass, 14,797 daltons), and its N-terminal residue, alanine, is N-acetylated. When compared to the sequences of known galectins, the B. arenarum galectin exhibited the highest identity (48% for the whole molecule and 77% for the carbohydrate recognition domain (CRD)) with the bovine spleen galectin-1, but surprisingly less identity (38% for the whole molecule and 47% for the CRD) with a galectin from Xenopus laevis skin (Marschal, P., Herrmann, J., Leffler, H., Barondes, S. H., and Cooper, D. N. W. (1992) J. Biol. Chem. 267, 12942-12949). Unlike the X. laevis galectin, the binding activity of the B. arenarum galectin for N-acetyllactosamine, the human blood group A tetrasaccharide and Galbeta1,3GalNAc relative to lactose, was in agreement with that observed for the galectin-1 subgroup and those galectins having "conserved" (type I) CRDs (Ahmed, H., and Vasta, G. R. (1994) Glycobiology 4, 545-549). Moreover, the toad galectin shares three of the six cysteine residues that are conserved in all mammalian galectins-1, but not in the galectins from X. laevis, fish, and invertebrates described so far. Based on the homologies of the B. arenarum galectin with the bovine spleen galectin-1 and X. laevis skin galectin, it should be concluded that within the galectin family the correlation between conservation of primary structure and phylogenetic distances among the source species may not be a direct one as proposed elsewhere (Hirabayashi, J., and Kasai, K. (1993) Glycobiology 3, 297-304). Furthermore, galectins with conserved (type I) CRDs, represented by the B. arenarum ovary galectin, and those with "variable" (type II) CRDs, represented by the X. laevis 16-kDa galectin, clearly constitute distinct subgroups in the extant amphibian taxa and may have diverged early in the evolution of chordate lineages. PMID:8955156

  11. Development of the nasal chemosensory organs in two terrestrial anurans: the directly developing frog, Eleutherodactylus coqui (Anura: Leptodactylidae), and the metamorphosing toad, Bufo americanus (Anura: Bufonidae).

    Science.gov (United States)

    Jermakowicz, Walter J; Dorsey, David A; Brown, Amy L; Wojciechowski, Karen; Giscombe, Claudette L; Graves, Brent M; Summers, Cliff H; Ten Eyck, Gary R

    2004-08-01

    Nearly all vertebrates possess an olfactory organ but the vomeronasal organ is a synapomorphy for tetrapods. Nevertheless, it has been lost in several groups of tetrapods, including aquatic and marine animals. The present study examines the development of the olfactory and vomeronasal organs in two terrestrial anurans that exhibit different developmental modes. This study compares the development of the olfactory and vomeronasal organs in metamorphic anurans that exhibit an aquatic larva (Bufo americanus) and directly developing anurans that have eliminated the tadpole (Eleutherodactylus coqui). The olfactory epithelium in larval B. americanus is divided into dorsal and ventral branches in the rostral and mid-nasal regions. The larval olfactory pattern in E. coqui has been eliminated. Ontogeny of the olfactory system in E. coqui embryos starts to vary substantially from the larval pattern around the time of operculum development, the temporal period when the larval stage is hypothesized to have been eliminated. The nasal anatomy of the two frogs does not appear morphologically similar until the late stages of embryogenesis in E. coqui and the terminal portion of metamorphosis in B. americanus. Both species and their respective developing offspring, aquatic tadpoles and terrestrial egg/embryos, possess a vomeronasal organ. The vomeronasal organ develops at mid-embryogenesis in E. coqui and during the middle of the larval period in B. americanus, which is relatively late for neobatrachians. Development of the vomeronasal organ in both frogs is linked to the developmental pattern of the olfactory system. This study supports the hypothesis that the most recent common ancestor of tetrapods possessed a vomeronasal organ and was aquatic, and that the vomeronasal organ was retained in the Amphibia, but lost in some other groups of tetrapods, including aquatic and marine animals. PMID:15216526

  12. Effect of Fish Oil on Liver Tumorigenesis and Biochemical Perturbations in Toads Treated with 7,12-Dimethylbenz (a) anthracene

    OpenAIRE

    Ismail A. Sadek; Kamal S. Ghazaly; Amina E. Essawy; Al-Attar, Atef M.

    2002-01-01

    The effect of fish oil on 7,12-dimethylbenz(a) anthracene (DMBA) - induced liver tumors in toads Bufo regularis was investigated. Feeding toads with DMBA 0.5 mg/toad twice weekly for 14 weeks, induced liver tumors (hepatocellular carcinomas) in 32 % of the treated animals. No tumors were detected in toads received DMBA plus 0.1 ml fish oil. Biochemical estimation of several parameters; total lipids, cholesterol, triglycerides, glutamic pyruvic acid transaminase (GPT) and glutamic oxalo...

  13. Assessment of age and intersexual size differences in Bufo bufo

    Directory of Open Access Journals (Sweden)

    Cvetkovi? Dragana D.

    2005-01-01

    Full Text Available Numerous studies have underlined the complex nature of relationship between age, size, and reproductive traits in anurans. One of the most intriguing problems for evolutionary biologists is intersexual difference in body size (SSD. For testing various hypotheses about SSD, we need reliable estimates of its extent (the important issue being the choice of trait for analysis as well as the accurate determination of individual age. The measures of SSD may be subject to error if estimated from populations with unknown age distribution; amphibians continue to grow throughout their life and SSD is linked to sex differences in traits such as age at maturity and lifespan. In the present paper, we analyze problems involved in accurate determination of age structure and factors that may lead to under- or overestimation of individual age, as well as the problem of appropriate choice of traits, in the light of our experience and results of investigating populations of common toad (Bufo bufo in the vicinity of Belgrade.

  14. Effects of salinity stress on Bufo balearicus and Bufo bufo tadpoles: Tolerance, morphological gill alterations and Na+/K+-ATPase localization

    International Nuclear Information System (INIS)

    Freshwater habitats are globally threatened by human-induced secondary salinization. Amphibians are generally poorly adapted to survive in saline environments. We experimentally investigated the effects of chronic exposure to various salinities (5%, 10%, 15%, 20%, 25%, 30% and 35% seawater, SW) on survival, larval growth and metamorphosis of tadpoles from two amphibian populations belonging to two species: the green toad Bufo balearicus and the common toad Bufo bufo. In addition, gill morphology of tadpoles of both species after acute exposure to hypertonic conditions (20%, 25%, and 30% SW) was examined by light and electron microscopy. Tadpoles experienced 100% mortality above 20% SW in B. balearicus while above 15% SW in B. bufo. We detected also sublethal effects of salinity stress on growth and metamorphosis. B. bufo cannot withstand chronic exposure to salinity above 5% SW, tadpoles grew slower and were significantly smaller than those in control at metamorphosis. B. balearicus tolerated salinity up to 20% SW without apparent effects during larval development, but starting from 15% SW tadpoles metamorphosed later and at a smaller size compared with control. We also revealed a negative relation between increasing salt concentration and gill integrity. The main modifications were increased mucous secretion, detachment of external layer, alteration of epithelial surface, degeneration phenomena, appearance of residual bodies, and macrophage immigration. These morphological alterations of gill epithelium can interfere with respiratory function and both osmotic and acid-base regulation. Significant variations in branchial Na+/K+-ATPase activity were also observed between two species; moreover an increase in enzyme activity was evident in response to SW exposure. Epithelial responses to increasing salt concentration were different in the populations belonging to two species: the intensity of histological and ultrastructural pathology in B. bufo was greater and we noticed the appearance in exposed samples of the tubular vesicle cells (TVCs). Taken together, our results demonstrated that increased salinity of freshwater may give cause for concern and must be considered a stressor for amphibians as well as other pollutants

  15. An invasive species induces rapid adaptive change in a native predator: cane toads and black snakes in Australia

    OpenAIRE

    Phillips, Ben L.; Shine, Richard

    2006-01-01

    Rapid environmental change due to human activities has increased rates of extinction, but some species may be able to adapt rapidly enough to deal with such changes. Our studies of feeding behaviour and physiological resistance to toxins reveal surprisingly rapid adaptive responses in Australian black snakes (Pseudechis porphyriacus) following the invasion of a lethally toxic prey item, the cane toad (Bufo marinus). Snakes from toad-exposed localities showed increased resistance to toad toxin...

  16. Characterization of urea transport in Bufo arenarum oocytes.

    Science.gov (United States)

    Silberstein, Claudia; Zotta, Elsa; Ripoche, Pierre; Ibarra, Cristina

    2003-07-01

    Xenopus laevis oocytes have been extensively used for expression cloning, structure/function relationships, and regulation analysis of transporter proteins. Urea transporters have been expressed in Xenopus oocytes and their properties have been described. In order to establish an alternative system in which urea transporters could be efficiently expressed and studied, we determined the urea transport properties of ovarian oocytes from Bufo arenarum, a toad species common in Argentina. Bufo oocytes presented a high urea permeability of 22.3 x 10(-6) cm/s, which was significantly inhibited by the incubation with phloretin. The urea uptake in these oocytes was also inhibited by mercurial reagents, and high-affinity urea analogues. The urea uptake was not sodium dependent. The activation energy was 3.2 Kcal/mol, suggesting that urea movement across membrane oocytes may be through a facilitated urea transporter. In contrast, Bufo oocytes showed a low permeability for mannitol and glycerol. From these results, we propose that one or several specific urea transporters are present in ovarian oocytes from Bufo arenarum. Therefore, these oocytes cannot be used in expression studies of foreign urea transporters. The importance of Bufo urea transporter is not known but could be implicated in osmotic regulation during the laying of eggs in water. PMID:12840834

  17. Trophic ecology and microhabitat utilization by the Bufo gargarizans, Rana guentheri, and Rana limnocharis in southwestern China

    OpenAIRE

    Tonglei Yu; Yanshu Guo

    2012-01-01

    We studied the trophic ecology and microhabitat use of the Asiatic toad, Bufo gargarizans Cantor, 1842; Guentheri frog, Rana guentheri (Boulenger, 1882); and the Ricefield frog, Rana limnocharis (Boie, 1834). These three species are common around Nanchong City, in southwestern China, where they live in the same habitat before hibernation. The main objective of this study was to analyze the diets and patterns of coexistence relative to the microhabitat of each species. In the Asiatic toad, bas...

  18. Effects of salinity stress on Bufo balearicus and Bufo bufo tadpoles: Tolerance, morphological gill alterations and Na{sup +}/K{sup +}-ATPase localization

    Energy Technology Data Exchange (ETDEWEB)

    Bernabò, Ilaria; Bonacci, Antonella; Coscarelli, Francesca [Department of Ecology, University of Calabria, Via P. Bucci, 87036 Rende (Cosenza) (Italy); Tripepi, Manuela [University of Pennsylvania, Department of Biology, 201 Leidy Laboratories, Philadelphia, PA 19104 (United States); Brunelli, Elvira, E-mail: brunelli@unical.it [Department of Ecology, University of Calabria, Via P. Bucci, 87036 Rende (Cosenza) (Italy)

    2013-05-15

    Freshwater habitats are globally threatened by human-induced secondary salinization. Amphibians are generally poorly adapted to survive in saline environments. We experimentally investigated the effects of chronic exposure to various salinities (5%, 10%, 15%, 20%, 25%, 30% and 35% seawater, SW) on survival, larval growth and metamorphosis of tadpoles from two amphibian populations belonging to two species: the green toad Bufo balearicus and the common toad Bufo bufo. In addition, gill morphology of tadpoles of both species after acute exposure to hypertonic conditions (20%, 25%, and 30% SW) was examined by light and electron microscopy. Tadpoles experienced 100% mortality above 20% SW in B. balearicus while above 15% SW in B. bufo. We detected also sublethal effects of salinity stress on growth and metamorphosis. B. bufo cannot withstand chronic exposure to salinity above 5% SW, tadpoles grew slower and were significantly smaller than those in control at metamorphosis. B. balearicus tolerated salinity up to 20% SW without apparent effects during larval development, but starting from 15% SW tadpoles metamorphosed later and at a smaller size compared with control. We also revealed a negative relation between increasing salt concentration and gill integrity. The main modifications were increased mucous secretion, detachment of external layer, alteration of epithelial surface, degeneration phenomena, appearance of residual bodies, and macrophage immigration. These morphological alterations of gill epithelium can interfere with respiratory function and both osmotic and acid-base regulation. Significant variations in branchial Na{sup +}/K{sup +}-ATPase activity were also observed between two species; moreover an increase in enzyme activity was evident in response to SW exposure. Epithelial responses to increasing salt concentration were different in the populations belonging to two species: the intensity of histological and ultrastructural pathology in B. bufo was greater and we noticed the appearance in exposed samples of the tubular vesicle cells (TVCs). Taken together, our results demonstrated that increased salinity of freshwater may give cause for concern and must be considered a stressor for amphibians as well as other pollutants.

  19. [The life cycle of Gorgoderina rochalimai Pereira and Cuocolo, 1940, a Digenea parasite of Bufo marinus in Guadeloupe].

    Science.gov (United States)

    Jourdane, J; Theron, A

    1975-01-01

    The sporocysts of G. rochalimai were found in Guadeloupe, in the bivalve Mollusc Sphaeriidae Eupera viridans. The cystocercous cercariae are ingested by Odonatan larvae in which the encystement occurs. The Toad Bufo marinus is the definitive host of the parasite. The life-cycle of G. rochalimai shows close similarities with the ones already known in many other speicies of Gorgoderidae. PMID:813553

  20. Toad envenoming in dogs: effects and treatment

    Scientific Electronic Library Online (English)

    M., SAKATE; P. C. LUCAS DE, OLIVEIRA.

    Full Text Available Toads (order: Anura; family: Bufonidae; genus: Bufo) are distributed throughout the world, but more species are found in areas of tropical and humid temperate climates. Although toads do not have a venom inoculation system, they are venomous animals because the glands covering the whole surface of t [...] heir bodies secrete a milk-like venom of which composition is not yet completely known. Some of these glands are the bilateral glands located in post-orbital position. These glands, which are somewhat diamond-shaped and can be seen by the naked eye, are known as parotids. Toad envenoming in dogs may cause local and systemic alterations and may cause death by cardiac ventricular fibrillation. The electrocardiographic alterations observed consist of gradual deterioration of the normal standards with progressive appearance of negative ventricular deflections that can result in ventricular fibrillation and death if the envenomed dog is not promptly treated. Traditional therapy consists mainly of administration of atropine and propranolol; the latter used to prevent ventricular fibrillation.

  1. Estimation of temporary emigration in male toads

    Science.gov (United States)

    Muths, E.; Scherer, R. D.; Corn, P.S.; Lambert, B.A.

    2006-01-01

    Male boreal toads (Bufo boreas) are thought to return to the breeding site every year but, if absent in a particular year, will be more likely to return the following year. Using Pollock's robust design we estimated temporary emigration (the probability a male toad is absent from a breeding site in a given year) at three locations in Colorado, USA: two in Rocky Mountain National Park and one in Chaffee County. We present data that suggest that not all male toads return to the breeding site every year. Our analyses indicate that temporary emigration varies by site and time (for example, from 1992 to 1998, the probability of temporary emigration ranged from 10% to 29% and from 3% to 95% at Lost Lake and Kettle Tarn, respectively). Although the results provide weak evidence that males are more likely to return after a year's hiatus, a general pattern of state-dependent temporary emigration was not supported. We also hypothesized relationships between temporary emigration and a number of weather variables. While some competitive models included weather covariates, imprecise and variable estimates of the effects of these covariates precluded fully defining their impact on temporary emigration. ?? 2006 by the Ecological Society of America.

  2. Toad venom poisoning: resemblance to digoxin toxicity and therapeutic implications

    Science.gov (United States)

    Gowda, R M; Cohen, R A; Khan, I A

    2003-01-01

    A healthy man developed gastrointestinal symptoms after ingesting purported aphrodisiac pills. He had severe unrelenting bradycardia, hyperkalaemia, and acidosis. He rapidly developed severe life threatening cardiac arrhythmias and died after a few hours. He was found to have positive serum digoxin concentrations, although he was not taking digoxin. Toad venom poisoning is similar to digitalis toxicity and carries a high mortality. Cardiac glycoside poisoning can occur from ingestion of various plants and animal toxins, and the venom gland of cane toad (Bufo marinus) contains large quantities of cardiac glycosides. Toad venom, a constituent of an aphrodisiac, was considered responsible for the development of clinical manifestations and death in this patient. Digoxin specific Fab fragment has been reported to be beneficial in the treatment of toad venom poisoning. This report alerts physicians to the need to be aware of a new community toxic exposure, as prompt treatment with digoxin specific Fab fragment may be life saving. The treatment approach to patients with suspected toad venom poisoning is described. PMID:12639891

  3. The ecological impact of invasive cane toads on tropical snakes: field data do not support laboratory-based predictions.

    Science.gov (United States)

    Brown, Gregory P; Phillips, Benjamin L; Shine, Richard

    2011-02-01

    Predicting which species will be affected by an invasive taxon is critical to developing conservation priorities, but this is a difficult task. A previous study on the impact of invasive cane toads (Bufo marinus) on Australian snakes attempted to predict vulnerability a priori based on the assumptions that any snake species that eats frogs, and is vulnerable to toad toxins, may be at risk from the toad invasion. We used time-series analyses to evaluate the accuracy of that prediction, based on >3600 standardized nocturnal surveys over a 138-month period on 12 species of snakes and lizards on a floodplain in the Australian wet-dry tropics, bracketing the arrival of cane toads at this site. Contrary to prediction, encounter rates with most species were unaffected by toad arrival, and some taxa predicted to be vulnerable to toads increased rather than declined (e.g., death adder Acanthophis praelongus; Children's python Antaresia childreni). Indirect positive effects of toad invasion (perhaps mediated by toad-induced mortality of predatory varanid lizards) and stochastic weather events outweighed effects of toad invasion for most snake species. Our study casts doubt on the ability of a priori desktop studies, or short-term field surveys, to predict or document the ecological impact of invasive species. PMID:21618921

  4. Karyological and flow cytometric evidence of triploid specimens in Bufo viridis (Amphibia Anura

    Directory of Open Access Journals (Sweden)

    D Cavallo

    2010-01-01

    Full Text Available Karyological and flow cytometric (FCM analyses were performed on a group of 14 green toads of the Bufo viridis species from seven Eurasian populations. Both approaches gave concordant results concerning the DNA ploidy level. All the populations examined were represented exclusively by diploid or tetraploid specimens, except one, where triploids were found. Results evidenced an interpopulation variability in DNA content against the same ploidy level, as well as an unusually high number of triploids in a particular reproductive place. The origin of polyploidy and the presence and persistence of a high number of triploids in a particular population are discussed.

  5. Resting respiratory behavior in minimally instrumented toads - effects of very long apneas on blood gases and pH

    Directory of Open Access Journals (Sweden)

    Coelho F. C.

    2003-01-01

    Full Text Available Resting respiratory behavior of Bufo marinus in minimally instrumented toads is described for a period of 24 hours in which the animals are left undisturbed. Torpor-related long apneas are described and their implications for blood gas levels are investigated. Results show that the resting ventilation rate of Bufo marinus is much lower than that reported so far. Levels of arterial oxygen, carbon dioxide, and pH are monitored during artificial long apneas induced by anesthesia. The toads showed an unexpected ability to unload carbon dioxide by non-respiratory means, even while being kept on dry plastic box with no access to water. Oxygen arterial partial pressure dropped to very low levels after one hour of apnea. This suggests that these animals may endure very well severe hypoxia for long periods of time while in torpor.

  6. Phospholipid transfer activities in toad oocytes and developing embryos

    International Nuclear Information System (INIS)

    The role of lipid transfer proteins during plasma membrane biogenesis was explored. Developing amphibia embryos were used because during their growth an active plasma membrane biosynthesis occurs together with negligible mitochondrial and endoplasmic reticulum proliferation. Sonicated vesicles, containing 14C-labeled phospholipids and 3H-labeled triolein, as donor particles and cross-linked erythrocyte ghosts as acceptor particles were used to measure phospholipid transfer activities in unfertilized oocytes and in developing embryos of the toad Bufo arenarum. Phosphatidylcholine transfer activity in pH 5.1 supernatant of unfertilized oocytes was 8-fold higher than the activity found in female toad liver supernatant, but dropped steadily after fertilization. After 20 hr of development, at the stage of late blastula, the phosphatidylcholine transfer activity had dropped 4-fold. Unfertilized oocyte supernatant exhibited phosphatidylinositol and phosphatidylethanolamine transfer activity also, but at the late blastula stage the former had dropped 18-fold and the latter was no longer detectable under our assay conditions. Our results show that fertilization does not trigger a phospholipid transport process catalyzed by lipid transfer proteins. Moreover, they imply that 75% of the phosphatidylcholine transfer activity and more than 95% of the phosphatidylinositol and phosphatidylethanolamine transfer activities present in pH 5.1 supernatants of unferti present in pH 5.1 supernatants of unfertilized oocytes may not be essential for toad embryo development. Our findings do not rule out, however, that a phosphatidylcholine-specific lipid transfer protein could be required for embryo early growth

  7. Trophic ecology and microhabitat utilization by the Bufo gargarizans, Rana guentheri, and Rana limnocharis in southwestern China

    Scientific Electronic Library Online (English)

    Tonglei, Yu; Yanshu, Guo.

    2012-02-01

    Full Text Available We studied the trophic ecology and microhabitat use of the Asiatic toad, Bufo gargarizans Cantor, 1842; Guentheri frog, Rana guentheri (Boulenger, 1882); and the Ricefield frog, Rana limnocharis (Boie, 1834). These three species are common around Nanchong City, in southwestern China, where they live [...] in the same habitat before hibernation. The main objective of this study was to analyze the diets and patterns of coexistence relative to the microhabitat of each species. In the Asiatic toad, based on index of relative importance, the diet was dominated by adult Coleoptera, Isopoda, and Hymenoptera (29.53%, 22.07%, and 15.20%, respectively), while the Guenther's frog and Ricefield frog ingested predominantly Orthoptera (67.44% and 40.94%, respectively). The standardized feeding niche breadth of the Asiatic toad (0.277) was wider than that of the Guentheri frog (0.177) and Ricefield frog (0.269). The overlap in the trophic niche (prey proportion) between the toad and two species of frog was low (toad vs. Guentheri frog, C H = 0.526; toad vs. Ricefield frog, C H = 0.521), while this was high for the two species of frogs (C H = 0.942). The three species also differed in microhabitat use. Asiatic toads showed strong preference for small roads close to shrubs or pre-harvest corn, while Guenther's frogs preferred bare surfaces on habitat edges, and Ricefield frogs showed a preference for bare surfaces as feeding sites in the middle of habitat. The difference in diet observed during three species seems to be explained by the difference in microhabitat use and body size of three species.

  8. Trophic ecology and microhabitat utilization by the Bufo gargarizans, Rana guentheri, and Rana limnocharis in southwestern China

    Directory of Open Access Journals (Sweden)

    Tonglei Yu

    2012-02-01

    Full Text Available We studied the trophic ecology and microhabitat use of the Asiatic toad, Bufo gargarizans Cantor, 1842; Guentheri frog, Rana guentheri (Boulenger, 1882; and the Ricefield frog, Rana limnocharis (Boie, 1834. These three species are common around Nanchong City, in southwestern China, where they live in the same habitat before hibernation. The main objective of this study was to analyze the diets and patterns of coexistence relative to the microhabitat of each species. In the Asiatic toad, based on index of relative importance, the diet was dominated by adult Coleoptera, Isopoda, and Hymenoptera (29.53%, 22.07%, and 15.20%, respectively, while the Guenther's frog and Ricefield frog ingested predominantly Orthoptera (67.44% and 40.94%, respectively. The standardized feeding niche breadth of the Asiatic toad (0.277 was wider than that of the Guentheri frog (0.177 and Ricefield frog (0.269. The overlap in the trophic niche (prey proportion between the toad and two species of frog was low (toad vs. Guentheri frog, C H = 0.526; toad vs. Ricefield frog, C H = 0.521, while this was high for the two species of frogs (C H = 0.942. The three species also differed in microhabitat use. Asiatic toads showed strong preference for small roads close to shrubs or pre-harvest corn, while Guenther's frogs preferred bare surfaces on habitat edges, and Ricefield frogs showed a preference for bare surfaces as feeding sites in the middle of habitat. The difference in diet observed during three species seems to be explained by the difference in microhabitat use and body size of three species.

  9. Intoxicação por veneno de sapo em um canino / Toad venom intoxication in a dog

    Scientific Electronic Library Online (English)

    Luciana, Sonne; Daniela Bernadete, Rozza; Adriana Nunes, Wolffenbüttel; Adriana Erica Wilkes Burton, Meirelles; Pedro Miguel Ocampos, Pedroso; Eduardo Conceição de, Oliveira; David, Driemeier.

    1787-17-01

    Full Text Available O sapo do gênero Bufo possui nas suas glândulas paratóides uma secreção mucóide contendo toxinas como bufaginas e Bufotoxinas, que são esteróides cardiogênicos. Os cães podem atacar os sapos, entrando em contato com o veneno por meio das mucosas. Um canino, da raça Bulldog Francês, foi encaminhado a [...] o Setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul (UFRGS) para a necropsia com histórico de provável intoxicação por veneno de sapo. Na necropsia o canino apresentava pulmões aumentados de volume, avermelhados e com edema, e rins de coloração vermelho-escura. As alterações microscópicas indicaram congestão, hemorragia e edema pulmonar. Nos rins, no baço e nos linfonodos foi observada congestão. As análises toxicológicas para os venenos de rotina foram negativas. Porém, a investigação do veneno de sapo a partir de cromatografia por camada delgada e gasosa demonstrou resultado positivo, revelando ser esta a causa da morte do canino. Abstract in english The toads of the genus Bufo produce, in their parotoid glands, a mucoid secretion containing toxins such as bufagins and Bufotoxins, which are cardiogenic steroids. The mucous membranes of dogs can absorb this venom when they attack the toads. A French bulldog with a history of probable toad venom i [...] ntoxication was referred to Veterinary Pathology Section of Federal University of Rio Grande do Sul (UFRGS) for necropsy. The necropsy revealed enlarged, reddish, edematous lungs, and kidneys displaying a dark red color. The microscopic alterations indicated the presence of congestion, hemorrhage, and pulmonary edema. Congestion was observed in the kidneys, spleen and lymph nodes. The routine toxicological analyses for venom detection were negative. Nevertheless, the toad venom test result was positive as assessed by thin layer and gas chromatography, indicating that toad venom intoxication was the cause of death.

  10. Immunohistochemical localisation of a galectin from Bufo arenarum ovary.

    Science.gov (United States)

    Elola, M T; Cabada, M O; Barisone, G A; Fink, N E

    1998-02-01

    Galectins are a group of soluble animal lectins that exhibit specificity for beta-galactosides and conserve sequence homology in the carbohydrate-recognition domain. The galectin from Bufo arenarum ovary showed a strong cross-reaction with the lectin of 14.5 kDa purified from embryos at early blastula stage. In this paper, we studied the immunohistochemical localisation of the galectin of 14.5 kDa from ovary of the toad B. arenarum in adult ovary sections. We also analysed the immunohistochemical localisation of the embryonic lectin during early development using the antiserum anti-ovary galectin. In the ovary, oocytes in the previtellogenic stage showed strong reactivity in the nucleus and the cortex but not in the cytoplasm. Oocytes in the stage of primary vitellogenesis exhibited a similar pattern in the nuclear and cortical areas but showed immunostaining in the cytoplasm. Intense nuclear staining was detected in oocytes in the stage of late vitellogenesis and in mature oocytes, which also presented strong reactions in the yolk platelets that completely covered the cytoplasm. In blastula embryos the staining was found in the blastomeres, the yolk platelets and the blastocoele. Each lectin localisation is discussed in relation to potential biological roles in the corresponding tissues. PMID:9652066

  11. Presynaptic neuromuscular action of a methanolic extract from the venom of Rhinella schneideri toad

    Scientific Electronic Library Online (English)

    Sandro, Rostelato-Ferreira; Cháriston A Dal, Belo; Gildo B, Leite; Stephen, Hyslop; Léa, Rodrigues-Simioni.

    2014-09-02

    Full Text Available Background Rhinella schneideri, previously known as Bufo paracnemis, is a common toad in many regions of Brazil. Its venom exerts important cardiovascular effects on humans and other animals. Although this toad venom has been the subject of intense investigations, little is known about its neuromus [...] cular activity. Methods The neurotoxicity of a methanolic extract of R. schneideri venom was tested on mouse phrenic nerve-diaphragm (PND) preparations mounted for conventional twitch tension recording – in response to indirect stimulation – and for electrophysiological measurements. Results Venom extract (50 ?g/mL) increased the muscle twitch tension in PND preparations but did not significantly alter the resting membrane potential values. Electrophysiological evaluations showed that the extract (50 ?g/mL) significantly augmented the frequency of miniature end-plate potential (from 38?±?3.5 to 88?±?15 after 60 minutes; n?=?5; p?

  12. The importance of glucose for the freezing tolerance/intolerance of the anuran amphibians Rana catesbeiana and Bufo paracnemis / A importância da glicose para a tolerância/intolerância ao congelamento dos anfíbios anuros Rana catesbeiana e Bufo paracnemis

    Scientific Electronic Library Online (English)

    A. A., STEINER; S. O., PETENUSCI; L. G., BRENTEGANI; L. G. S., BRANCO.

    2000-05-01

    Full Text Available Diversas espécies de rãs terrestres, tartarugas e insetos desenvolveram mecanismos para resistência ao congelamento, como o aumento dos níveis de glicose, proteínas anticongelantes e enzimas antioxidantes. Neste estudo, verificou-se a importância da glicose para a crioresistência de dois anfíbios an [...] uros: a rã Rana catesbeiana e o sapo Bufo paracnemis. Os animais foram expostos a -2ºC para medidas de glicemia, conteúdo de glicogênio muscular e hepático, hematócrito e volume celular das hemácias. As rãs sobreviveram à exposição, enquanto os sapos não. A glicemia aumentou de 40,35 ± 7,25 para 131,87 ± 20,72 mg/dl (P Abstract in english Several species of terrestrially hibernating frogs, turtles and insects have developed mechanisms, such as increased plasma glucose, anti-freeze proteins and antioxidant enzymes that resist to freezing, for survival at subzero temperatures. In the present study, we assessed the importance of glucose [...] to cryoresistance of two anuran amphibians: the frog Rana catesbeiana and the toad Bufo paracnemis. Both animals were exposed to -2ºC for measurements of plasma glucose levels, liver and muscle glycogen content, haematocrit and red blood cell volume. Frogs survived cold exposure but toads did not. Blood glucose concentration increased from 40.35 ± 7.25 to 131.87 ± 20.72 mg/dl (P

  13. Haematological changes in Bufo maculatus treated with sublethal concentrations of Cadmium

    Directory of Open Access Journals (Sweden)

    Alex Ajeh Enuneku

    2011-05-01

    Full Text Available Adult Bufo maculatus was exposed to sublethal cadmium concentrations of 0.25, 0.50, 1.00 and 2.00 mg/L. The toxicant from which the cadmium concentrations were prepared was cadmium chloride (CdCl2.H2O. There were three replicate tanks per treatment and three individuals per tank including control groups. The hematologic alterations based on the examination of blood indices during the 28 days of exposure showed that total erythrocyte count (TEC, hematocrit (Hct and hemoglobin (Hb concentration decreased (PBufo maculatus toad to cadmium can inflict alterations in the hematologic indices, which could induce unfavorable physiological changes in the amphibian, which may lead to death. There is, therefore, the need to protect amphibians in order to sustain the biodiversity in the Nigerian Niger Delta ecological zone.

  14. A Research of Peripheral Blood Cells Annually in Bufo Bufo gargarizans / Investigación de las Células Sanguíneas Periféricas en un Periodo Anual del Bufo Bufo gargarizans

    Scientific Electronic Library Online (English)

    Chongbin, Liu; Chengqiang, Xia; Zhaohui, Xie; Yang, Jiao; Qiusheng, She.

    2013-12-01

    Full Text Available Se realizó el presente estudio histológico de las células sanguíneas de Bufo Bufo gargarizans en diferentes meses del año: enero, marzo, mayo, julio y octubre. Fueron utilizados métodos de rutina por frotis de sangre con tinción de Wright y observación in vivo. Encontramos dos tipos principales de c [...] élulas de glóbulos rojos al frotis como también en células in vivo: mitóticas y amitóticas. Por cuanto amitosis se produce durante todo el año, sobre todo en el mes de julio, la mitosis hasta el momento se había observado solamente en julio. Además, se encontró una gran cantidad de neutrófilos en los glóbulos de Bufo Bufo gargarizans. Los núcleos de estas células son polimórficos, especialmente en enero y marzo. La concentración de glóbulos rojos era más bajo en mayo y más alta en enero; la concentración de las células blancas de la sangre fue mayor en octubre y menor en marzo. En cuanto a los granulocitos, eosinófilos estos presentaron una mayor proporción en julio y octubre, mientras que los neutrófilos y basófilos registraran una mayor proporción en el mes de julio. Los agranulocitos y las células mononucleares alcanzaron el valor más alto en marzo, y el valor más bajo en enero. Los linfocitos y el valor máximo fue registrado en mayo, el valor más bajo fue registrado en julio. No fueron evidentes los cambios morfológicos de trombocitos, lo que podría tener relación con su estabilidad. Abstract in english The present paper deals with a histological study of the blood cells of Bufo Bufo gargarizans in different months: January, March, May, July and October. The methods used are by routine blood smear in Wright stain and observation in vivo. We found that in smears and in vivo two main types of cells o [...] f the red cells: mitotic as well as amitotic. While amitotic occurs all the year round, particularly in July, mitosis so far had been seen only in July. It is also found that there are plenty of neutrophils in the blood cells of Bufo Bufo gargarizans, furthermore, the nuclei of these cells are polymorphic, especially in January and March. Meanwhile, the concentration of red cells was lowest in May and highest in January; The concentration of white blood cells was highest in October and lowest in March; As to granulocytes, eosinophils in July and October had higher proportion, while neutrophils and basophils in July; in agranulocytes, mononuclear cells reached the highest value in March, lowest in January, lymphocytes and the maximum value appeared in May, the lowest value appeared in July. Morphological changes of thrombocytes were not obvious.

  15. The importance of glucose for the freezing tolerance/intolerance of the anuran amphibians Rana catesbeiana and Bufo paracnemis

    Directory of Open Access Journals (Sweden)

    STEINER A. A.

    2000-01-01

    Full Text Available Several species of terrestrially hibernating frogs, turtles and insects have developed mechanisms, such as increased plasma glucose, anti-freeze proteins and antioxidant enzymes that resist to freezing, for survival at subzero temperatures. In the present study, we assessed the importance of glucose to cryoresistance of two anuran amphibians: the frog Rana catesbeiana and the toad Bufo paracnemis. Both animals were exposed to -2ºC for measurements of plasma glucose levels, liver and muscle glycogen content, haematocrit and red blood cell volume. Frogs survived cold exposure but toads did not. Blood glucose concentration increased from 40.35 ± 7.25 to 131.87 ± 20.72 mg/dl (P < 0.01 when the frogs were transferred from 20 to -2ºC. Glucose accumulation in response to cold exposition in the frogs was accompanied by a decrease (P < 0.05 in liver glycogen content from 3.94 ± 0.42 to 1.33 ± 0.36 mg/100 mg tissue, indicating that liver carbohydrate reserves were probably the primary carbon source of glucose synthesis whereas muscle carbohydrate seems unimportant. In the toads, the cold-induced hyperglycaemia was less (P < 0.05 pronounced (from 27.25 ± 1.14 to 73.72 ± 13.50 mg/dl and no significant change could be measured in liver or muscle glycogen. Cold exposition had no effect on the haematocrit of the frogs but significantly reduced (P < 0.01 the haematocrit of toads from 20.0 ± 2.1% to 5.8 ± 1.7% due to a decreased red blood cell volume (from 1532 ± 63 to 728 ± 87 mm³. When toads were injected with glucose, blood glucose increased to levels similar to those of frogs and haematocrit did not change, but this failed to make them cryoresistent. In conclusion, the lack of cold-induced glucose catabolism may not be the only mechanism responsible for the freeze intolerance of Bufo paracnemis, a freeze-intolerant species.

  16. Expression of N-CAM-180 and N-Cadherin during development in two southamerican anuran species (Bufo arenarum and Hyla nana)

    OpenAIRE

    VH. Casco; A Peralta Soler; MF. Izaguirre

    2009-01-01

    Cadherins and N-CAM are Ca++-dependent and Ca++-independent cell adhesion molecules respectively. These molecules play a key role in morphogenesis and histogenesis. We determined the spatiotemporal pattern of N-cadherin and N-CAM-180 kDa expression by immunohistochemistry during development in two South-American anuran species (Bufo arenarum, toad and Hyla nana, frog). Both N-cadherin and N-CAM were not detectable during early developmental stages. Expression of Ncadherin appeared between the...

  17. Estudo sôbre hemoparasitos de Bufo marinus L. da Venezuela: 1. Hemogregarinas - - 2. Uma nova espécie de Toxoplasma

    Scientific Electronic Library Online (English)

    José Vicente, Scorza; Cecilia, Dagert B.; Luís Iturriza, Arocha.

    1956-10-01

    Full Text Available Faz-se uma revisão das espécies de Haemogregarina, encontradas, até a presente data, em Bufo marinus L. da região Norte, Leste e Sul da Venezuela,descrevendo-se o ciclo agâmico da Haemogregarina darlingi Leger, 1918, o ciclo esquizogônico da Haemogregarina aquai Phisalix, 1930, propondo-se seja deno [...] minada Karyolysus aquai (Phisalix) por realizar o ciclo agâmico nas células endoteliais. Descreve-se a Haemogregarina legeri nov. sp. Estuda-se um Toxoplasma no sangue e vísceras de Bufo marinus L., descrevendo-se a anatomia patológica dos órgãos afetados, discutindo-se o estado atual da sistemática das espécies de Toxoplasma, parasitos de vertebrados poikilotermos, propondo-se o nome de Toxoplasma serpai nov. sp. para êste protozoário. Abstract in spanish Se hace una revisión de las especies de Haemogregarina encontradas hasta el presente en Bufo marinus L. de la región neotrópica, estudiando estos parásitos en sapos del centro, norte, oriente y sur de Venezuela, describiendo el ciclo agamico de la Haemogregarina darlingi Leger 1918, el ciclo esquizo [...] gonico de la Haemogregarina aquai Phisalix 1930, proponiendo denominaria Karyolysus aquai (Phisalix) por realizar su ciclo agámico en las células endoteliales. Se describe la Haemogregarina legeri nov. sp. Se estudia un Toxoplasma en la sangre y visceras de bufo marinus L. describiendo la anatomia patológica de los órganos afectados, discutiendose el estado actual de la sistematica de Toxoplasma parasitos de vertebrados poikilotermos, proponiendo el nombre de Toxoplasma serpai nov. sp. para este protozoario. Abstract in english A revision is made of the species of Haemogregarina found up to now in Bufo marinus L. from the Neotropical Region. Parasites in toads from the north, center, south and east of Venezuela are studied and descriptions are made of the agamic cycle of Haemogregarina darlingi Leger 1918; the schizogonic [...] cycle of Haemogregarina aquai Phisalix 1930, proposing reclassify it as Karyolysus aquai (Phisalix) since its agamic cycle is carried through in endothelial cells, and Haemogregarina legeri nov. sp. A Toxoplasma is studied in the blood and viscera of Bufo marinus L. describing the pathology of affected organs, proposing the name Toxoplasma serpai nov. sp. for it. The actual state of the systematics of Toxoplasma parasites in poikilotherm vertebrates is discussed.

  18. THE HELMINTH PARASITOFAUNA OF BUFO REGULARIS (REUSS IN AWKA, ANAMBRA STATE, NIGERIA

    Directory of Open Access Journals (Sweden)

    NWORAH DC, OLORUNFEMI OJ

    2011-12-01

    Full Text Available The term "toad" tends to refer to the "True Toads".... which are members of the family Bufonidae, containing more than300 species. One hundred specimens of Bufo regularis (67 males and 33 females were collected between June 2006 andAugust 2006 in Awka metropolis of Anambra State of Nigeria and examined for helminth parasites or for non-protozoan gut andtissue parasites. Seventy one percent (71% (48 males and 23 females of the specimens were infected by five hundred andforty-three (543 parasitic helminthes made up of 475(89% nematodes, 6(2% pentastomids and 62(14% trematodes. Theseseven species collected include Nematoda: Ascaridoid larva (12%, Rhabdias bufonis(30%, Camallanus sp.(10%, Amplicaecumafricanum(31%, Ascaridoid(6%; Trematoda: Messocoelium monodi(14%; Pentastomida: Raillietiella sp.(6%.Amplicaecum africanum was most prevalent in males with 24% than in females 7%. Also Rhabdias bufonis was most prevalent inmales with 19% than in females 11% and the differences were statistically significant. Prevalence also varied with length andweight. Male toads in the length classes of 11.0-11.9cm and 12.0-12.9cm had the highest prevalence of 100% while those in 7.0-7.9cm length class had the least prevalence of 60%. Females in the 10.0-10.9cm length class had the highest prevalence of81.82% while those in 9.0-9.9cm length class had the least prevalence of 50% (P<0.05. Males in 101-120g weight class had thehighest prevalence of 100% while those in the 61-80g weight class had the least prevalence of 63.64%. Females in 141-160gweight class had the highest prevalence of 100%while those in the weight classes of 41-60g, 61-80g and 81-100g had the leastprevalence of 75% and the differences were statistically significant.(P<0.05. All the helminths exhibited site preferences exceptone nematode, Amplicaecum africanum, recovered from rectum, intestine and stomach of both male and female toads.Parasite abundance was variable from one toad size class to another. It appeared that there was a general tendency for theprevalences to increase with increase in size of the host.

  19. NHE-1 sequence and expression in toad, snake and fish red blood cells

    DEFF Research Database (Denmark)

    Thomsen, Steffen Nyegaard; Wang, Tobias

    Red blood cells (RBC) from reptiles appear not to express regulatory volume increase (RVI) upon shrinkage (Kristensen et al., 2008). In other vertebrates, the RVI response is primarily mediated by activation of the Na+/H+ exchanger (NHE-1) and we, therefore decided to investigate whether red cells of reptiles express a different NHE-1 that responds less to volume activation compared to other vertebrates or simply lack the Na+/H+ exchanger. Using various tissues from the ball python (Python regius), Cane toad (Bufo marinus) and European perch (Perca fluviatilis), cDNA libraries were created and sequenced using PCR with primers generated from a clustal alignment of available NHE-1 sequences in the NR database. Having established the presence of the NHE-1 gene in python, cane toad and perch, expression was quantified by Western Blot and Immunoconfocal microscopy using fluorophore coupled NHE-1 antibodies. These studies showed that NHE-1 is expressed in RBCs from both toads and teleosts fish, but is not expressed in the RBCs of pythons. Thus, the lack of the RVI response in pythons is likely to reflect the lack of capacity to exchange Na+ and H+ for volume regulation.

  20. Effects of weather on survival in populations of boreal toads in Colorado

    Science.gov (United States)

    Scherer, R. D.; Muths, E.; Lambert, B.A.

    2008-01-01

    Understanding the relationships between animal population demography and the abiotic and biotic elements of the environments in which they live is a central objective in population ecology. For example, correlations between weather variables and the probability of survival in populations of temperate zone amphibians may be broadly applicable to several species if such correlations can be validated for multiple situations. This study focuses on the probability of survival and evaluates hypotheses based on six weather variables in three populations of Boreal Toads (Bufo boreas) from central Colorado over eight years. In addition to suggesting a relationship between some weather variables and survival probability in Boreal Toad populations, this study uses robust methods and highlights the need for demographic estimates that are precise and have minimal bias. Capture-recapture methods were used to collect the data, and the Cormack-Jolly-Seber model in program MARK was used for analysis. The top models included minimum daily winter air temperature, and the sum of the model weights for these models was 0.956. Weaker support was found for the importance of snow depth and the amount of environmental moisture in winter in modeling survival probability. Minimum daily winter air temperature was positively correlated with the probability of survival in Boreal Toads at other sites in Colorado and has been identified as an important covariate in studies in other parts of the world. If air temperatures are an important component of survival for Boreal Toads or other amphibians, changes in climate may have profound impacts on populations. Copyright 2008 Society for the Study of Amphibians and Reptiles.

  1. Mortality and toxin bioaccumulation in Bufo marinus following exposure to Cylindrospermopsis raciborskii cell extracts and live cultures

    International Nuclear Information System (INIS)

    Cylindrospermopsis raciborskii is a cyanobacterium responsible for the production of the toxin, cylindrospermopsin (CYN). Tadpoles of the cane toad Bufo marinus were exposed to freeze-thawed whole cell extracts or live cultures of C. raciborskii containing maximum CYN concentrations of 400 ?g L-1 or 232 ?g L-1, respectively. Exposure to live culture treatment solutions resulted in up to 66% mortality of B. marinus, whereas tadpoles exposed to whole cell extracts containing similar toxin concentrations survived. Decreases in relative growth rates and time spent for swimming were recorded from tadpoles during both types of exposure regimes. Bioconcentration of CYN was not evident following exposure to whole cell extracts containing extracellular toxin. In contrast exposure to live cultures, which contained cell-bound toxin, resulted in maximum average tissue concentrations of 895 ?g free-CYN kg-1 fresh weight. This is the first investigation of C. raciborskii exposure effects and toxin bioaccumulation in the developmental stages of an amphibian. - Cane toad tadpoles experienced adverse effects and bioaccumulation of toxin following exposure to the cyanobacterium Cylindrospermopsis raciborskii

  2. Within- and among-population level differences in response to chronic copper exposure in southern toads, Anaxyrus terrestris

    International Nuclear Information System (INIS)

    Environmental contaminants are implicated in the global decline of amphibian populations. Copper (Cu) is a widespread contaminant that can be toxic at concentrations just above the normal physiological range. In the present study we examined the effects of chronic Cu aqueous exposure on embryos and larvae of southern toads, Anaxyrus (Bufo) terrestris. Measurable levels of Cu were found in larvae, with tissue concentrations up to 27.5 ?g Cu/g dry mass. Aqueous concentrations of Cu as low as 10 ?g/L significantly reduced survival to the free-swimming stage and no larvae reached metamorphosis at concentrations above 15 ?g/L. Clutches from populations with prior Cu exposure had the lowest survivorship. Among several populations there was significant variation in survivorship at different levels of Cu. More data are needed to understand the underlying causes of within- and among-population resilience to anthropogenic stressors. -- Highlights: ? Southern toad, Anaxyrus terrestris, embryos and larvae are highly sensitive to Cu. ? Significant variation in survivorship exists among clutches and populations. ? Clutches with prior Cu exposure had the lowest survivorship. ? Body burdens in larvae were up to 27.5 ?g Cu/g dry mass. -- Capsule: Southern toad aquatic survival is significantly reduced at 15 ?g Cu/L with variation in survivorship across clutches and populations

  3. Structure of the kidney of Bufo arenarum: Intermediate segment, distal tubule and collecting tubule

    Directory of Open Access Journals (Sweden)

    Alejandro Farías

    2003-04-01

    Full Text Available The ultrastructure of the intermediate segment (IS, distal tubule and collecting tubule (CT of the south american toad Bufo arenarum, was studied by light and transmission electron microscopy. The IS is composed of cubical ciliated cells which propel the urine along the renal tubule. The distal tubule is divided into two portions: the early distal tubule (EDT and the late distal tubule (LDT. The EDT is characterized by only one type of cells with well developed basolateral interdigitations and numerous elongated mitochondria, which are oriented normal to the basal surface. The "macula densa - like" is a specialized zone of the EDT in contact with the vascular pole, where cells are more tightly packed than in the rest of the tubule. The LDT shows two types of cells called dark and light cells according to the appearance of their cytoplasm. Dark cells have microplicae and few but long microvilli at their luminal surface, and abundant mitochondria in their cytoplasm. Light cells show basal and lateral infoldings and few mitochondria. The CT, which is composed of dark and light cells, exhibits an enlarged lumen with an undulated surface and dilated spaces between neighbouring cells. This work is a contribution to the knowledge of the kidney of B. arenarum; frequently used as an experimental model for physiological and biochemical studies.

  4. 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 considered one of the luckiest parasites, because it has found an empty niche in Australia. It now flourishes in > 20 endemic and exotic frog species, but its consequences are yet to be fully understood.

  5. Study on Comparative Histology of Retinas in Ctenopharyngodon idella, Cynops orientalis, Bufo bufo gargarizans, Gekko japonicus, and Columba livia / Estudio Histológico Comparado de la Retina en Ctenopharyngodon Idella, Cynops Orientalis, Bufo Bufo Gargarizans, Gekko Japonicus, y Columba Livia

    Scientific Electronic Library Online (English)

    Qiusheng, She; Zhenqiang, An; Chengqiang, Xia; Yunfei, Kong; Enxiang, Chen.

    2014-09-01

    Full Text Available El objetivo de este estudio fue explorar la relación entre las estructuras de la retina y su adaptación al medioambiente en Ctenopharyngodon idella, Cynops orientalis, Bufo bufo gargarizans,Gekko japonicus y Columba livia . La medición del espesor de cada capa de la retina, la capa nuclear y su diám [...] etro en los cinco animales, mostró a través del análisis estadístico que las capas nucleares en todos ellos fueron 4, y sus estructuras se pueden dividir en 10 capas cuando se observan con el microscopio óptico. El espesor de la retina de Ctenopharyngodon idella fue 190,49 µm, de Cynops orientalis fue 173,07 µm, de Bufo bufo gargarizans fue 195,06 µm, de Gekko japonicus fue 224,32 µm y de Columba livia fue 174,10 µm. El número de capas nucleares internas de la retina de Bufo gargarizans, Gekko japonicus y Columba livia fue mayor que sus capas nucleares externas, mientras que las capas nucleares internas de Ctenopharyngodon idella y Cynops orientalis fueron menos que las capas nucleares externas. La capa de conos y bastones de la retina de Cynops orientalis fue más desarrollada, pero su capa de fibras nerviosas presentó una elevada degeneración, lo que muestra una gran fotosensibilidad, pero una sensibilidad visual baja. En Columba livia, la capa de fibras nerviosas de la retina estuvo muy desarrollada, y de esta manera, su visión. El grado de desarrollo de las diferentes estructuras y funciones de la retina de Ctenopharyngodon idella, Cynops orientalis, Bufo bufo gargarizans, Gekko japonicus y Columba livia está relacionada con sus características de comportamiento y el cambio de las condiciones de las vidas acuática y anfibia en la tierra. Abstract in english The objective of this study was to explore the relationship between the retinal structure and its life adaptation to the environment of Ctenopharyngodon idella, Cynops orientalis, Bufo bufo gargarizans, Gekko japonicus and Columba livia . Measuring retinal thickness of each layer, the nuclei layer, [...] and the diameter of each nuclear layer of the five animals, the statistical data analysis shows that: the nuclei layers of five animals are all 4, and their structures can be divided to 10 layers when observing with optical microscope. The retinal thickness of Ctenopharyngodon idella was 190.49 mm, Cynops orientalis was 173.07 µm, and the Bufo bufo gargarizans was 195.06 µm, Gekko japonicus was 224.32 µm and Columba livia was 174.10 µm. The number of retinal inner nuclear layers of Bufo bufo gargarizans and Gekko japonicus and Columba livia are more than their outer nuclear layers, on the contrary, retinal inner nuclear layers of Ctenopharyngodon idella and Cynops orientalis are less than their outer nuclear layers. The rod and cone layer of retina of Cynops orientalis were more advanced, but their nerve fiber layer (NFL) degraded highly, revealing a strong photosensitivity but a low visual sensitivity; to Columba livia , their NFL of retina are highly developed, so as their vision. The different structures and functions of the retina of Ctenopharyngodon idella, Cynops orientalis, Bufo bufo gargarizans, Gekko japonicus and Columba livia correspond with their behavioral characteristics and the living environment's change from aquatic to amphibious to land.

  6. Sexual selection in cane toads Rhinella marina: A male’s body size affects his success and his tactics

    Directory of Open Access Journals (Sweden)

    Haley BOWCOCK, Gregory P. BROWN, Richard SHINE

    2013-12-01

    Full Text Available Male body size can play an important role in the mating systems of anuran amphibians. We conducted laboratory-based trials with cane toads Rhinella (Bufo marina from an invasive population in the wet-dry tropics of northern Australia, to clarify the effects of a male's body size on his reproductive success and behavior (mate choice. Males were stimulated with a synthetic hormone to induce reproductive readiness. Larger body size enhanced a male toad's ability to displace a smaller rival from amplexus, apparently because of physical strength: more force was required to dislodge a larger than a smaller amplectant male. A male’s body size also affected his mate-choice criteria. Males of all body sizes were as likely to attempt amplexus with another male as with a female of the same size, and preferred larger rather than smaller sexual targets. However, this size preference was stronger in larger males and hence, amplexus was size-assortative. This pattern broke down when males were given access to already-amplectant male-female pairs: males of all body sizes readily attempted amplexus with the pair, with no size discrimination. An amplectant pair provides a larger visual stimulus, and prolonged amplexus provides a strong cue for sex identification (one of the individuals involved is almost certainly a female. Thus, a male cane toad’s body size affects both his ability to defeat rivals in physical struggles over females, and the criteria he uses when selecting potential mates, but the impacts of that selectivity depend upon the context in which mating occurs [Current Zoology 59 (6: 747–753, 2013].

  7. critical habitat designated for the arroyo toad

    US Fish and Wildlife Service, Department of the Interior — These data identify the areas (in general) of critical habitat designated for the arroyo toad. NOTE: THIS DATA SET INCLUDES APPROXIMATELY 900 ACRES OF LAND...

  8. Molecular cloning and analysis of Myc modulator 1 (Mm-1) from Bufo gargarizans (Amphibia: Anura)

    Scientific Electronic Library Online (English)

    Ning, Wang; Rui, Jia; Jing J., Wang; Liu W., Nie.

    2010-02-01

    Full Text Available The protein of Myc modulator 1 (Mm-1) has been reported to repress the transcriptional activity of the proto-oncogene c-Myc in humans. Moreover, it was shown to be the subunit 5 of human prefoldin (PFD). So far, this gene and its homologs have been isolated and sequenced in many organisms, such as m [...] ammals and fish, but has not been sequenced for any amphibian or reptile. In order to better understand the function and evolution of Mm-1, we isolated a full-length Mm-1 cDNA (BgMm-1, GenBank accession no. EF211947) from Bufo gargarizans (Cantor, 1842) using RACE (rapid amplification of cDNA ends) methods. Mm-1 in B. gargarizans is 755 bp long, comprising an open reading frame (ORF) of 459 bp encoding 152 amino acids. The amino acid sequence had a prefoldin ?-like domain, partially including a typical putative leucine zipper motif. BgMm-1 showed high similarity to its homolog of Mus musculus Linnaeus, 1758 (82%) and Homo sapiens Linnaeus, 1758 MM-1 isoform a (81%) at the amino acid level. The protein secondary structure modeled with the SWISS MODEL server revealed that there were two ?-helices and four b-strands in BgMm-1 as its human orthologue, and both proteins belonged to the a class of PFD family. The phylogenetic relationships of Mm-1s from lower archaea to high mammals was consistent with the evolution of species, meanwhile the cluster result was consistent with the multiple alignment and the sequence identity analysis. RT-PCR (reverse transcriptase-polymerase chain reaction) analysis demonstrated that BgMm-1 expressed widely in ten tissues of adult toad. These results can be helpful for the further investigation on the evolution of Mm-1.

  9. Molecular cloning and analysis of Myc modulator 1 (Mm-1 from Bufo gargarizans (Amphibia: Anura

    Directory of Open Access Journals (Sweden)

    Ning Wang

    2010-02-01

    Full Text Available The protein of Myc modulator 1 (Mm-1 has been reported to repress the transcriptional activity of the proto-oncogene c-Myc in humans. Moreover, it was shown to be the subunit 5 of human prefoldin (PFD. So far, this gene and its homologs have been isolated and sequenced in many organisms, such as mammals and fish, but has not been sequenced for any amphibian or reptile. In order to better understand the function and evolution of Mm-1, we isolated a full-length Mm-1 cDNA (BgMm-1, GenBank accession no. EF211947 from Bufo gargarizans (Cantor, 1842 using RACE (rapid amplification of cDNA ends methods. Mm-1 in B. gargarizans is 755 bp long, comprising an open reading frame (ORF of 459 bp encoding 152 amino acids. The amino acid sequence had a prefoldin ?-like domain, partially including a typical putative leucine zipper motif. BgMm-1 showed high similarity to its homolog of Mus musculus Linnaeus, 1758 (82% and Homo sapiens Linnaeus, 1758 MM-1 isoform a (81% at the amino acid level. The protein secondary structure modeled with the SWISS MODEL server revealed that there were two ?-helices and four b-strands in BgMm-1 as its human orthologue, and both proteins belonged to the a class of PFD family. The phylogenetic relationships of Mm-1s from lower archaea to high mammals was consistent with the evolution of species, meanwhile the cluster result was consistent with the multiple alignment and the sequence identity analysis. RT-PCR (reverse transcriptase-polymerase chain reaction analysis demonstrated that BgMm-1 expressed widely in ten tissues of adult toad. These results can be helpful for the further investigation on the evolution of Mm-1.

  10. Determinación de la frecuencia de micronúcleos en eritrocitos de Bufo arenarum que habitan ambientes urbanizados / Determination of micronuclei frequency in erythrocytes of Bufo arenarum inhabiting urbanized environments

    Scientific Electronic Library Online (English)

    Evangelina, Caraffa; Clarisa del L, Bionda; Favio E, Pollo; Nancy E, Salas; Adolfo L, Martino.

    2013-12-01

    Full Text Available Los anfibios son constituyentes integrales de ecosistemas naturales y agrícolas, y debido a su sensibilidad pueden ser utilizados como bioindicadores. La frecuencia de micronúcleos se emplea como un biomarcador que evalúa la respuesta a agentes genotóxicos. El objetivo del trabajo fue determinar y c [...] omparar la frecuencia de micronúcleos en eritrocitos de Bufo arenarum que habitan ambientes antrópicos de la ciudad de Río Cuarto. Se escogieron tres sitios modificados: un lago urbano Lago Villa Dálcar (33º06´S-64º22´W) y dos sitios de cultivo denominados Cultivo1 (33º05'S-64º26'W) y Cultivo 2 (33º05'S-64º25'W). Como control se escogió un área ubicada en las sierras de Comechingones, en el Campo Experimental Las Guindas (32º35'S- 64º42'W), pertenecientes a la UNRC. En cada sitio se recolectaron ocho individuos utilizando trampas de caída y relevamientos por encuentros visuales. A cada individuo se le extrajo sangre de la vena angularis inmediatamente después de la captura. Se realizaron dos extendidos por cada individuo, se dejaron secar al aire por 24 hs, luego se fijaron con metanol por 20 minutos y se colorearon con Giemsa al 5% durante 10 minutos. Posteriormente los frotis fueron analizados con microscopio (1000X) y se tomaron fotografías con cámara digital. La frecuencia de micronúcleos fue contabilizada para 4000 células por individuo. Se realizaron comparaciones utilizando el test de Kruskal-Wallis. Las frecuencias de micronúcleos encontradas son: Las Guindas: 0,17 ± 0,23; Cultivo1: 0,78 ± 0,28; Cultivo 2: 0,61 ± 0,45 y Villa Dálcar: 0,76 ± 0,47. Existen diferencias significativas entre el control y los demás sitios (p Abstract in english Amphibians are integral constituents of natural and agricultural ecosystems, and because of their sensitivity can be used as bioindicators. Micronuclei test is used as a biomarker for determining the response to genotoxic agents. The purpose of this study was to determine and compare the frequency o [...] f micronuclei in peripheral blood erythrocytes of Bufo arenarum toads that inhabiting anthropic environments for the city of Rio Cuarto. Organisms used in the MN test were collected from three sites modified: an urban lakeVilla Dalcar (33º06´S-64º22´W) and two cultivation sites called Crop 1 (33º05'S-64º26'W) and Crop 2 (33º05'S-64º25'W). As a control site, an area in the mountains of Comechingones, Las Guindas (32º35'S-64º42'W), belonging to the UNRC was sampled. At each site, eight individuals were collected using pitfall traps and by visual encounter surveys. To each individual is bled from the vein angularis immediately after capture. We performed two extended for each individual, air-dried for 24 hours, then fixed with methanol for 20 minutes and stained with 5% Giemsa for 10 minutes. Then the smears were analyzed with microscope (1000X) and took pictures with digital camera. For each individual the frequency of micronuclei for 4000 cells was recorded. Comparisons were made using the Kruskal-Wallis test. Micronuclei frequencies found are: Las Guindas: 0.17± 0.23; Crop 1: 0.78 ± 0.28, Crop 2: 0.61 ± 0.45 and Villa Dalcar: 0.76 ± 0.47. There are significant differences between the control and the other sites (p

  11. Toad poisoning in three dogs: case reports

    Directory of Open Access Journals (Sweden)

    CM Barbosa

    2009-01-01

    Full Text Available Toad poisoning is frequent in dogs, but has been infrequently addressed in published case reports and review articles. Dogs can be poisoned when they bite a toad or otherwise ingest the venom. The venom effects manifest soon after the accident, since the toxin is rapidly absorbed by the mucous membrane of the digestive system. Hospital records of three dogs, diagnosed with toad poisoning, were retrospectively reviewed from January 2005 to July 2007. Poisoned dogs may present only local irritation or systemic signs in the gastrointestinal, cardiac and neurological systems. All three cases presented herein had clinical signs of gastrointestinal alterations including vomiting, sialorrhea and diarrhea. Two dogs developed abnormal cardiac rhythm and two exhibited neurological signs. A poisoned animal requires emergency care and symptomatic therapy with intense monitoring of its clinical parameters. Although there have been reports on the low mortality of dogs poisoned by toads, one animal died even after appropriate therapy. The severity of clinical signs and the risk of death must be considered by the veterinarian.

  12. Toad poisoning in three dogs: case reports

    Scientific Electronic Library Online (English)

    CM, Barbosa; MS, Medeiros; CCM, Riani Costa; AC, Camplesi; M., Sakate.

    Full Text Available Toad poisoning is frequent in dogs, but has been infrequently addressed in published case reports and review articles. Dogs can be poisoned when they bite a toad or otherwise ingest the venom. The venom effects manifest soon after the accident, since the toxin is rapidly absorbed by the mucous membr [...] ane of the digestive system. Hospital records of three dogs, diagnosed with toad poisoning, were retrospectively reviewed from January 2005 to July 2007. Poisoned dogs may present only local irritation or systemic signs in the gastrointestinal, cardiac and neurological systems. All three cases presented herein had clinical signs of gastrointestinal alterations including vomiting, sialorrhea and diarrhea. Two dogs developed abnormal cardiac rhythm and two exhibited neurological signs. A poisoned animal requires emergency care and symptomatic therapy with intense monitoring of its clinical parameters. Although there have been reports on the low mortality of dogs poisoned by toads, one animal died even after appropriate therapy. The severity of clinical signs and the risk of death must be considered by the veterinarian.

  13. Comparing and Contrasting with Frog and Toad

    Science.gov (United States)

    Rebecca Childs

    2012-04-09

    In this lesson, students will learn how to compare and contrast the experiences of the familiar characters, Frog and Toad, by completing t-charts and writing a simple paragraph about the similarities and differences in the characters' experiences across stories.

  14. The envelopes of amphibian oocytes: physiological modifications in Bufo arenarum

    OpenAIRE

    Sánchez Mercedes; Albertali Isabel E; Barisone Gustavo A; Cabada Marcelo O

    2003-01-01

    Abstract A characterization of the Amphibian Bufo arenarum oocyte envelope is presented. It was made in different functional conditions of the oocyte: 1) when it has been released into the coelomic cavity during ovulation (surrounded by the coelomic envelope, (CE), 2) after it has passed through the oviduct and is deposed (surrounded by the viteline envelope, (VE), and 3) after oocyte activation (surrounded by the fertilization envelope, (FE). The characterization was made by SDS-PAGE followe...

  15. Comparative cytogenetic studies of Bufo ictericus, B. paracnemis (Amphibia, Anura and an intermediate form in sympatry

    Directory of Open Access Journals (Sweden)

    Azevedo MFC

    2003-01-01

    Full Text Available Specimens of Bufo ictericus, Bufo paracnemis and a third type, considered an intermediate subgroup between these species, were cytogenetically studied by conventional Giemsa staining, C-banding and staining of the nucleolus organizer region (NOR. The nuclear DNA content and seroproteins were also analyzed to characterize these species, and verify the possibility of hybridization between them. Karyotypes and cytogenetic markers were essentially equal on the basis of the methods used. The DNA nuclear content found was 6.25 ± 0.30 pg/DNA in Bufo ictericus; 7.57 ± 0.40 pg/DNA in Bufo paracnemis and 7.04 ± 0.29 pg/DNA in the intermediate subgroup. Eletrophoresis of total blood serum in Bufo ictericus, Bufo paracnemis and the intermediate specimens revealed a remarkable difference in the patterns of the protein bands whose molecular weight corresponded to that of albumin. While the parental species presented two different bands, the intermediate form presented 4. However, only three of these bands were seen in each specimen. The results obtained pointed to a high probability for natural hybridization between Bufo ictericus and Bufo paracnemis in the site and specimens studied.

  16. Comparative cytogenetic studies of Bufo ictericus, B. paracnemis (Amphibia, Anura) and an intermediate form in sympatry

    Scientific Electronic Library Online (English)

    MFC, Azevedo; F., Foresti; PRR, Ramos; J, Jim.

    Full Text Available Specimens of Bufo ictericus, Bufo paracnemis and a third type, considered an intermediate subgroup between these species, were cytogenetically studied by conventional Giemsa staining, C-banding and staining of the nucleolus organizer region (NOR). The nuclear DNA content and seroproteins were also a [...] nalyzed to characterize these species, and verify the possibility of hybridization between them. Karyotypes and cytogenetic markers were essentially equal on the basis of the methods used. The DNA nuclear content found was 6.25 ± 0.30 pg/DNA in Bufo ictericus; 7.57 ± 0.40 pg/DNA in Bufo paracnemis and 7.04 ± 0.29 pg/DNA in the intermediate subgroup. Eletrophoresis of total blood serum in Bufo ictericus, Bufo paracnemis and the intermediate specimens revealed a remarkable difference in the patterns of the protein bands whose molecular weight corresponded to that of albumin. While the parental species presented two different bands, the intermediate form presented 4. However, only three of these bands were seen in each specimen. The results obtained pointed to a high probability for natural hybridization between Bufo ictericus and Bufo paracnemis in the site and specimens studied.

  17. Aerobic scope and cardiovascular oxygen transport is not compromised at high temperatures in the toad Rhinella marina

    DEFF Research Database (Denmark)

    Overgaard, Johannes; Andersen, Jonas Lembcke

    2012-01-01

    Numerous recent studies convincingly correlate the upper thermal tolerance limit of aquatic ectothermic animals to reduced aerobic scope, and ascribe the decline in aerobic scope to failure of the cardiovascular system at high temperatures. In the present study we investigate whether this "aerobic scope model" applies to an air-breathing and semi-terrestrial vertebrate Rhinella marina (formerly Bufo marinus). To quantify aerobic scope, we measured resting and maximal rate of oxygen consumption at temperatures ranging from 10 to 40°C. To include potential effects of acclimation, three groups of toads were acclimated chronically at 20, 25 and 30°C, respectively. The absolute difference between resting and maximal rate of oxygen consumption increased progressively with temperature and there was no significant decrease in aerobic scope, even at temperature immediately below the lethal limit (41-42°C). Hematological and cardio-respiratory variables were measured at rest and immediately after maximal activity at benign (30°C) and critically high (40°C) temperatures. Within this temperature interval, both resting and active heart rate increased, and there was no indication of respiratory failure, judged from high arterial oxygen saturation, PO(2) and [HbO(2)]. With the exception of elevated resting metabolic rate for cold acclimated toads, we found few differences in the thermal responses between acclimation groups with regard to the cardio-metabolic parameters. In conclusion, we found no evidence for temperature induced cardio-respiratory failure in Rhinella marina indicating that maintenance of aerobic scope and oxygen transport is unrelated to the upper thermal limit of this air-breathing semi-terrestrial vertebrate.

  18. Concentration dependence of halide fluxes and selectivity of the anion pathway in toad skin

    DEFF Research Database (Denmark)

    Harck, A F; Larsen, Erik Hviid

    1986-01-01

    The isolated toad (Bufo bufo) skin was mounted under voltage-clamp conditions in a chamber shown to cause no significant edge damage. The serosal side of the skin was bathed with NaCl-Ringer's, and the passive voltage-sensitive anion conductance studied in its fully voltage activated state, V = -80 mV (apical bath negative). The active sodium currents were eliminated by replacing external Na+ with K+. With [Cl-]o varying between 1.45 mM and 110 mM (gluconate substitution) and [I-]o = 3 mM, the total clamping current (y) and the sum of halide currents (x), estimated from flux measurements, were related by y = 1.0x-3.7 microA cm-2 (r2 = 0.98, n = 50 preparations). The increase in [Cl-]o produced a sigmoidal increase in Cl- influx and clamping current, with the rate coefficient for the influx increasing with [Cl-]o for 1.45 less than [Cl-]o less than 60 mM, but decreasing slightly again as [Cl-]o was further raised to 110 mM. A similar relationship was obtained between the rate coefficient for the Br- influx and[Br-]o, and the I- influx and [Cl-]o, indicating that these three ions are transported by a pathway that is activated by Cl-o and Br-o. The rate coefficients for the influxes ranked as follows, I-:Cl-:Br- = 0.7:1:1.3. The I-/Cl- selectivity was shown to be independent of the degree of Cl-o activation of the anion pathway, and identical with the I-/Cl- selectivity of a furosemide-sensitive, conductive pathway. With [Cl-]o, [Br-]o, or [I-]o = 110 mM, the currents ranked as follows, Cl-:Br-:I- = 1:0.68:0.06, indicating that Cl-, to a lesser extent Br-, and I-, poorly activate the conductive anion pathway. External I- was a potent inhibitor of the Cl-o activation of the Cl- conductance. The unidirectional I- fluxes ([I-]o = [I-]i = 3 mM, [Cl-]o = [Cl-]i = 110 mM) revealed passive transport for V less than -50 mV, active transport for V = o mV, and exchange diffusion for V = 50 mV, confirming our previous finding that depending on the transepithelial potential, the toad skin exhibits three modes of anion transport. A model that shares some properties with that of the anion transport system of the red cell membrane accounts for our findings, and for an inwardly directed active Cl- flux in terms of Cl-/HCO3- exchange.

  19. Further Hopping with Toads and Frogs

    CERN Document Server

    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.

  20. Helmintos parásitos de anfibios: Dos Especies de Nemátodos parásitos de Bufo spinulosus trifolium (Tschudi

    Directory of Open Access Journals (Sweden)

    Asucena Naupay

    2014-06-01

    Full Text Available En el presente trabajo sobre los helmintos que parasitan a Bufo spinulosus trifolium (Tschudi de la localidad de Huánuco, se presentan dos especies conocidas para la ciencia pero una de ellas nueva para el Perú.

  1. Bufo toxin: A new testing prospect for the screening of anti-convulsant agents. A review

    OpenAIRE

    David Arome; Agbafor Amarachi

    2014-01-01

    Epilepsy is a common neurological disorder with diverse aetiology, affecting approximately 1 % of the entire population. Epilepsy present wide range of clinical manifestations, that affect the way a person feels and acts for a short time. Previous scientific investigations have indicated bufo toxin as a potential convulsant candidate that produced similar effects as other known convulsant agents. Bufo toxin has been shown to mimic or exhibit similar action as other known convulsant agent. Its...

  2. Variación ontogenética en la palatibilidad de los renacuajos de Bufo spinulosus papillosus Philippi, 1902 (Anura: Bufonidae

    Directory of Open Access Journals (Sweden)

    Jara, Fabián Gastón

    2006-03-01

    Full Text Available Se evaluó la variación ontogenética de la palatabilidad en Bufo spinulosus papillosus expuestos a larvas del odonato Rhionaeshna variegata (Odonata, Aeshnidae. Los renacuajos fueron agrupados en cuatro categorías de desarrollo y fueron expuestos a la depredación directa determinándose el número de renacuajos consumidos al finalizar los experimentos. Bufo spinulosus papillosus no fue palatable en los primeros estadios del desarrollo (categorías I, estadios 24-26 y categoría II, estadios 32-34, mientras que los estadios de las categoría III (estadios 38-40 y categoría IV (estadios 42-45 fueron progresivamente palatables. Se observó un comportamiento de rechazo por parte de los depredadores luego de la captura de renacuajos de las categorías I y II. El patrón de palatabilidad encontrado en Bufo spinulosus papillosus difiere del observado en otras especies relacionadas del género Bufo (Brodie y Formanowicz, 1987; Kehr y Schnack, 1991; Lawler y Hero, 1997. We evaluated the ontogenetic variation in the palatability of Bufo spinulosus papillosus tadpoles exposed to odonate larvae of Rhionaeshna variegata (Odonata, Aeshnidae. We exposed tadpoles to direct predation and determined the number of consumed tadpoles in four developmental categories. Bufo spinulosus papillosus tadpoles of categories I (stages 24-26 and II (stages 32-34 were unpalatable, while categories III (stages 38-40 and IV (stages 42-45 were progressively palatable. We observed a post-capture rejection behavior when they caught unpalatable tadpoles in categories I and II. The palatability pattern observed in Bufo spinulosus papillosus was different from related Bufo species (Brodie and Formanowicz, 1987; Kehr and Schnack, 1991; Lawler and Hero, 1997.

  3. Biogeographic patterns of Colombian frogs and toads

    International Nuclear Information System (INIS)

    Using the data provided in Ruiz-Carranza et al. (1996) the distributions of the 540 species of frogs and toads are partitioned among ten ecogeographic units of Colombia defined on the basis of precipitation and elevation. Some lowlands areas (pacific lowlands, Amazonian) exhibit high diversity (85-94 species) but lowlands areas in general are impoverished (30-52 species), especially when contrasted with upland areas. The three Andean cordilleras harbor between 87 and 121 species of frogs and toads, demonstrating that the biodiversity of Colombia resides primarily in its montane components, not in its lowland rain forests. When biological endemicity is separated from political endemicity, five areas of high endemicity remain (the three Andean cordilleras, the Sierra Nevada de Santa Marta, and the pacific lowlands). We endeavor to explain this description by recourse to cladistic analyses of several groups of leptodactylid frogs where we find that the general pattern of diversification is by means of horizontal diversification (allopatric speciation) with a minor contribution from vertical diversification

  4. Bufo toxin: A new testing prospect for the screening of anti-convulsant agents. A review

    Directory of Open Access Journals (Sweden)

    David Arome

    2014-07-01

    Full Text Available Epilepsy is a common neurological disorder with diverse aetiology, affecting approximately 1 % of the entire population. Epilepsy present wide range of clinical manifestations, that affect the way a person feels and acts for a short time. Previous scientific investigations have indicated bufo toxin as a potential convulsant candidate that produced similar effects as other known convulsant agents. Bufo toxin has been shown to mimic or exhibit similar action as other known convulsant agent. Its biochemical components are formed as a result of the binding of bufo-fagin and a molecule arginina. There exist wide array of convulsant agents used in the screening of anti-convulsant agents. The commonly used one are: bicuculline, picrotoxin, pentylene tetrazole, isonizid etc. However, these agents are expensive, not easily available and affordable. This challenge prompted the search of other alternative convulsant agents that is easily accessible for use in the screening of anti-convulsant agents. The principal objective of this review paper is to suggest the possible use of bufo toxin which mimics the action of existing convulsant agents. This new testing convulsant agent (bufo toxin is inexpensive, affordable and easy to use when compared to other known convulsant agents. The experimental procedure is easy and it gives a broad spectrum in comparing the action of bufo toxin to other chemical convulsant agents. It also offers researchers broader view or options in exploring the anti-convulsant activity of test agents and the understanding of their possible mechanism of action.

  5. Responsiveness of the hypothalamo-pituitary-interrenal axis in an amphibian (Bufo terrestris) exposed to coal combustion wastes

    International Nuclear Information System (INIS)

    To assess the responsiveness of the interrenal axis to stress, we injected toads exposed to coal combustion wastes and toads from an unpolluted reference site with adrenocorticotropic hormone (ACTH), as well as the vehicle alone (saline). Initial circulating levels of corticosterone in toads captured at the polluted area were significantly higher than levels in toads from the reference site. Corticosterone levels in toads from the polluted site remained high even after 2 weeks of laboratory acclimation and injection with saline. The results may suggest disruption of hepatic enzymes responsible for the metabolic clearance of steroid hormones. Injection of toads from the polluted site with ACTH had no effect on plasma corticosterone levels, whereas a similar treatment of toads from the reference site stimulated a marked increase in corticosterone. Our study provides evidence that toads exposed to coal combustion wastes may be less efficient at responding to additional environmental stressors. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  6. Stereological analysis of mitochondria in embryos of Rana temporaria and Bufo bufo during cleavage

    Directory of Open Access Journals (Sweden)

    Ewa Krzysztofowicz

    2011-08-01

    Full Text Available Total numbers of mitochondria and their morphology have been quantitatively determined in mature oocytes and in cleaving embryos of two anuran species Rana temporaria and Bufo bufo using stereological methods. Surface densities of inner mitochondrial membranes for both studied species during cleavage ranged from 5.43 m2/cm3 to 7.53 m2/cm3, whereas volume densities of mitochondria did not exceed 1.65%. Since values of these parameters were low, thus embryos during cleavage may be considered as metabolically "silent". Transition of ultrastructural morphology of mitochondria towards that characterising actively respiring organelles occurs at stage 9 for R. temporaria and at stage 8 for B. bufo, correlated with blastula-gastrula and mid-blastula transition, respectively. The total numbers of mitochondria N(c in mature oocytes are as high as 114.8 and 107.2 millions for R. temporaria and B. bufo, respectively, and during cleavage at late blastula stages they increase to 300 millions for both species under study. We suggest that an undefined mechanism might eliminate during cleavage those amphibian embryos which contain small number of mitochondria and low levels of nutrient substances.

  7. Humoral immune alterations caused by lead: studies on an adult toad model / Alteraciones inmunes humorales causadas por plomo: estudios en un modelo de sapo adulto

    Scientific Electronic Library Online (English)

    Carolina E., Rosenberg; Nilda E., Fink; Alfredo, Salibián.

    2007-07-01

    Full Text Available Existe evidencia de que los niveles de metal ambientales afectan la función inmune. En el caso particular del impacto de metales pesados, la información disponible sugiere que el sistema inmune es un blanco para la exposición a bajas dosis de Pb. Entre los vertebrados, se ha mostrado que los anfibio [...] s son capaces de formar anticuerpos contra una variedad de antígenos, que causan diversas respuestas, tales como respuesta anafiláctica y rechazo de injertos. En este estudio, la producción de anticuerpos fue evaluada contra eritrocitos de oveja (EO) en el anuro Bufo arenarum, luego de seis inyecciones semanales de dosis subletales de plomo (50 mg.kg-1, como acetato de Pb). Los anticuerpos naturales (heteroaglutininas naturales) fueron también cuantificados contra EO. Ambas evaluaciones fueron llevadas a cabo empleando un método de ELISA desarrollado a este fin, midiendo la absorbancia (A). Para los anticuerpos anti-EO naturales, tanto en sapos controles (C) como en sapos tratados con Pb (T), hubo una tendencia significativa a incrementar las absorbancias iniciales (C inicial: 0,69±0,39 A; T inicial: 0,54±0,30 A); la relación T/C tampoco mostró cambios. La única diferencia significativa se encontró entre las muestras inicial y final de los sapos tratados con plomo (p Abstract in english There is evidence that environmental metal levels affect the immune function. In the particular case of the impact of heavy metals, information available suggests that the immune system is a target for low-dose Pb exposure. Among vertebrates it was shown that amphibians are capable of forming antibo [...] dies against a variety of antigens, causing several responses such as anaphylactic response and rejecting grafts. In this study, the production of antibodies was assessed against sheep red blood cells (SRBC) in the anuran Bufo arenarum after six weekly injections of sublethal doses of lead (50 mg.kg-1, as lead acetate). Natural antibodies (natural heteroagglutinins) were also quantified against SRBC. Both assessments were carried out employing an ELISA method developed to this end, measuring absorbance (A). For natural anti-SRBC antibodies in both control (C) and Pb treated (T) toads, there was a non significant tendency to increase the initial absorbances (C initial: 0.69±0.39 A; T initial: 0.54±0.30 A), relative to those registered at the end of the experiments (C final: 0.89±0.49 A; T final: 0.76±0.31A); the T/C ratios also did not show changes. The only significant difference was found between initial and final samples from lead-treated toads (p

  8. Morfologia da glândula intermaxilar do sapo (Bufo paracnemis Lutz, 1925

    Directory of Open Access Journals (Sweden)

    Marlene Soares Dias Alves

    1988-01-01

    Full Text Available The intermaxillary gland of Bufo paracnemis Lutz, 1925 is located at the pre-nasal area being divided anteriorly by the ascendent processes of the intermaxillary bone. The secretory tubules converge to form very ramified ducts which drain into a common opening in a fosseta underlying the vomer bone. The cells of the intermaxillary gland were be classified in four distinct types: Light-granule secretory; Dark-granule secretory; ciliated and basal cells. The light-granule secretory cells, are the main type of the secretory tubules, which are also found, in smaller numbers, in the excretory ducts. The dark-granule secretory cells appear in a low number, both in the secretory tubules and in the excretory ducts. Degranulated cells are frequently found in the excretory ducts and represent the degranulated phase of dark-granule secretory cells. The ciliated cells occur only in the excretory ducts. The basal cells occur in small number in the excretory ducts and secretory tubules. In the excretory ducts these cells are regarded as being mioepithelial cells. Although usually described in the literature as mucous, the secretory cells of the intermaxillary gland have serous characteristics. The intermaxillary gland is the first salivary gland to appear in the vertebrate evolution. Its duct system is uniformly lined by ciliated cells and scattered secretory cells. This indicates that in the evolution, of salivary glands, there was a diversification of the duct system, together with progressxve concentration of secretory cells in special áreas of this system.

  9. Morfologia da glândula intermaxilar do sapo (Bufo paracnemis Lutz, 1925)

    Scientific Electronic Library Online (English)

    Marlene Soares Dias, Alves.

    Full Text Available [...] Abstract in english The intermaxillary gland of Bufo paracnemis Lutz, 1925 is located at the pre-nasal area being divided anteriorly by the ascendent processes of the intermaxillary bone. The secretory tubules converge to form very ramified ducts which drain into a common opening in a fosseta underlying the vomer bone. [...] The cells of the intermaxillary gland were be classified in four distinct types: Light-granule secretory; Dark-granule secretory; ciliated and basal cells. The light-granule secretory cells, are the main type of the secretory tubules, which are also found, in smaller numbers, in the excretory ducts. The dark-granule secretory cells appear in a low number, both in the secretory tubules and in the excretory ducts. Degranulated cells are frequently found in the excretory ducts and represent the degranulated phase of dark-granule secretory cells. The ciliated cells occur only in the excretory ducts. The basal cells occur in small number in the excretory ducts and secretory tubules. In the excretory ducts these cells are regarded as being mioepithelial cells. Although usually described in the literature as mucous, the secretory cells of the intermaxillary gland have serous characteristics. The intermaxillary gland is the first salivary gland to appear in the vertebrate evolution. Its duct system is uniformly lined by ciliated cells and scattered secretory cells. This indicates that in the evolution, of salivary glands, there was a diversification of the duct system, together with progressxve concentration of secretory cells in special áreas of this system.

  10. Expression of N-CAM-180 and N-Cadherin during development in two southamerican anuran species (Bufo arenarum and Hyla nana

    Directory of Open Access Journals (Sweden)

    VH Casco

    2009-12-01

    Full Text Available Cadherins and N-CAM are Ca++-dependent and Ca++-independent cell adhesion molecules respectively. These molecules play a key role in morphogenesis and histogenesis. We determined the spatiotemporal pattern of N-cadherin and N-CAM-180 kDa expression by immunohistochemistry during development in two South-American anuran species (Bufo arenarum, toad and Hyla nana, frog. Both N-cadherin and N-CAM were not detectable during early developmental stages. Expression of Ncadherin appeared between the inner and the outer ectoderm layers at stages 19-20. At stages 24 -25, Ncadherin was expressed in the neural tube and the heart. In early tadpoles, N-cadherin expression increased along with the central nervous system (CNS morphogenesis, and reached its maximum level at metamorphic climax stage. N-Cadherin expression was not uniformly distributed. At stage 42, olfactory placodes and retina expressed N-cadherin. Contrary to N-CAM, the strongly myelinated cranial nerves were not labeled. N-Cadherin was present in several mesoderm derivatives such as the notochord, heart and skeletal muscle. The non-neural ectoderm and the endoderm were always negative. Expression of N-CAM appeared first in the neural tube at stages 24-25 and the level of expression became uniform from pre-metamorphic to metamorphic climax tadpoles. At this latter stage, a clear N-CAM immunolabeling appeared in the nerve terminals of pharynx and heart. N-Cadherin and N-CAM were found mainly co-expressed in the CNS from early tadpole to metamorphic climax tadpole. Our results show that the expression of N-CAM and N-cadherin is evolutionary conserved. Their increased expression during late developmental stages suggests that N-CAM and N-cadherin are involved in cell contact stabilization during tissue formation.

  11. Phosphorus-31 nuclear magnetic resonance spectroscopy of toad retina.

    OpenAIRE

    Apte, D. V.; Koutalos, Y.; Mcfarlane, D. K.; Dawson, M. J.; Ebrey, T. G.

    1989-01-01

    Phosphorus-31 nuclear magnetic resonance (31P-NMR) spectra were obtained from living toad retinae and toad retinal extracts at 4 degrees C. Several phosphorus metabolites--nucleoside di- and triphosphates (NTP), phosphocreatine, phosphodiesters, inorganic phosphate, and phosphomonoesters--were identified from the spectra of whole retinae. The intracellular pH was determined to be 7.27 +/- 0.06 at 4 degrees C and the intracellular MgNTP/NTP ratio was at least 0.77. These results are consistent...

  12. The envelopes of amphibian oocytes: physiological modifications in Bufo arenarum

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    Sánchez Mercedes

    2003-02-01

    Full Text Available Abstract A characterization of the Amphibian Bufo arenarum oocyte envelope is presented. It was made in different functional conditions of the oocyte: 1 when it has been released into the coelomic cavity during ovulation (surrounded by the coelomic envelope, (CE, 2 after it has passed through the oviduct and is deposed (surrounded by the viteline envelope, (VE, and 3 after oocyte activation (surrounded by the fertilization envelope, (FE. The characterization was made by SDS-PAGE followed by staining for protein and glycoproteins. Labeled lectins were used to identify glycosidic residues both in separated components on nitrocellulose membranes or in intact oocytes and embryos. Proteolytic properties of the content of the cortical granules were also analyzed. After SDS-PAGE of CE and VE, a different protein pattern was observed. This is probably due to the activity of a protease present in the pars recta of the oviduct. Comparison of the SDS-PAGE pattern of VE and FE showed a different mobility for one of the glycoproteins, gp75. VE and FE proved to have different sugar residues in their oligosaccharide chains. Mannose residues are only present in gp120 of the three envelopes. N-acetyl-galactosamine residues are present in all of the components, except for gp69 in the FE. Galactose residues are present mainly in gp120 of FE. Lectin-binding assays indicate the presence of glucosamine, galactose and N-acetyl galactosamine residues and the absence (or non-availability of N-acetyl-glucosamine or fucose residues on the envelopes surface. The cortical granule product (CGP shows proteolytic activity on gp75 of the VE.

  13. A network extension of species occupancy models in a patchy environment applied to the Yosemite toad (Anaxyrus canorus)

    Science.gov (United States)

    Berlow, Eric L.; Knapp, Roland A.; Ostoja, Steven M.; Williams, Richard J.; McKenny, Heather; Matchett, John R.; Guo, Qinghau; Fellers, Gary M.; Kleeman, Patrick; Brooks, Matthew L.; Joppa, Lucas

    2013-01-01

    A central challenge of conservation biology is using limited data to predict rare species occurrence and identify conservation areas that play a disproportionate role in regional persistence. Where species occupy discrete patches in a landscape, such predictions require data about environmental quality of individual patches and the connectivity among high quality patches. We present a novel extension to species occupancy modeling that blends traditionalpredictions of individual patch environmental quality with network analysis to estimate connectivity characteristics using limited survey data. We demonstrate this approach using environmental and geospatial attributes to predict observed occupancy patterns of the Yosemite toad (Anaxyrus (= Bufo) canorus) across >2,500 meadows in Yosemite National Park (USA). A. canorus, a Federal Proposed Species, breeds in shallow water associated with meadows. Our generalized linear model (GLM) accurately predicted ~84% of true presence-absence data on a subset of data withheld for testing. The predicted environmental quality of each meadow was iteratively ‘boosted’ by the quality of neighbors within dispersal distance. We used this park-wide meadow connectivity network to estimate the relative influence of an individual Meadow’s ‘environmental quality’ versus its ‘network quality’ to predict: a) clusters of high quality breeding meadows potentially linked by dispersal, b) breeding meadows with high environmental quality that are isolated from other such meadows, c) breeding meadows with lower environmental quality where long-term persistence may critically depend on the network neighborhood, and d) breeding meadows with the biggest impact on park-wide breeding patterns. Combined with targeted data on dispersal, genetics, disease, and other potential stressors, these results can guide designation of core conservation areas for A. canorus in Yosemite National Park.

  14. Cosmocerca parva Travassos, 1925 (Nematoda: Cosmocercidae) in Toads from Argentina

    OpenAIRE

    Cecilia Mordeglia; María Celina Digiani

    1998-01-01

    Cosmocerca parva Travassos 1925 (Asca-ridida, Cosmocercoidea, Cosmocercidae) was originally described from Helosia nasus (Leptodactylidae) of Angra dos Reis, State of Rio de Janeiro, Brazil. It has also been reported in Leptodactylus chaquensis, L. elenae, Hyla fuscovaria and Bufo paracnemis from Paraguay (MR Baker & C Vaucher 1984 Rev Suisse Zool 91: 299-307). This note enlarges the known morphological variability of C. parva in a new host and makes amend for previous descriptions wit...

  15. Il rospo smeraldino Bufo viridis in Val d’Ossola (Amphibia: Anura: Bufonidae)

    OpenAIRE

    Fabio Casale; Radames Bionda; Franco Zanghellini; Alessandro Marsilli; Claudio Torboli

    2006-01-01

    Vengono riportate le osservazioni di rospo smeraldino (Bufo viridis) compiute tra il 1998 e il 2004 in Val d’Ossola (provincia del Verbano Cusio Ossola), un’area nella quale questa specie non era stata mai precedentemente segnalata.

  16. Bufoténine et bufoténidine : des alcaloïdes aux vertus hallucinogènes et aphrodisiaques extraits du venin de crapaud Bufotenine and bufotenidine : hallucinogenic and aphrodisiac alleged alcaloids extracted from toad venom

    Directory of Open Access Journals (Sweden)

    Anger Jean-Pierre

    2008-02-01

    Full Text Available La bufoténine (5-hydroxy-N,N-diméthyltryptamine est un alcaloïde indolique de la famille des tryptamines comme la sérotonine, la N-méthylsérotonine, la 5-méthoxy-N-méthyltryptamine et la mélatonine retrouvées dans les graines de certaines légumineuses ainsi que dans les sécrétions de la peau de différents amphibiens. Chez l'homme, ces molécules possèdent de puissantes propriétés psychotropes et sont impliquées dans les désordres mentaux temporaires ou dans des maladies du cerveau comme la schizophrénie et autres symptômes psychotiques, probablement du fait de leur point commun tant sur le plan structural que physiologique avec le L.S.D, vis à vis du récepteur 5-HT2. Le présent travail se propose de faire le point sur la composition et les propriétés du venin de crapaud, ses prétendues vertus hallucinogènes et aphrodisiaques, ce que l'on sait actuellement de ses effets sur l'homme et des risques d'intoxication. Historiquement les crapauds Bufo ont été extrêmement importants pour différentes cultures à travers le monde, durant des millénaires. Ils semblent aujourd'hui susceptibles de nous aider à comprendre et peut-être même un jour à diagnostiquer la survenue de maladies aussi déroutantes que la schizophrénie ou l'autisme et même qui sait, à les guérir. Diverses publications font état de l'usage de ces sécrétions par ingestion ou par inhalation pour leurs effets psychoactifs aux Etats-Unis et en Australie. Cet usage ne semble pas encore répandu en France. On peut souhaiter que le venin de Bufo ne prenne jamais le relais des drogues existantes et qu'au contraire, on puisse y découvrir d'autres molécules d'intérêt thérapeutique. Bufotenin (5-hydroxy-N,N-dimethyltryptamine is a tryptamine alkaloid, such as serotonin, N-methylserotonin, 5- methoxy-N-methylserotonin and melatonin, widely distributed in the leguminosae family and commonly found in a number of vertebrate as mammals and in many amphibian groups around the world. In human, these molecules show potent psychotropic properties an are usually associated to temporary mental disorders and brain deseases such as schizophrenia and other psychotic symptoms, probably due to their similar physiological and structural features to LSD in the 5HT2 receptor. The present study investigates the properties of toad venom, its hallucinogenic and aphrodisiac alleged properties, what we know about its psychedelic effects and the toxicological hazards for humans. Some papers report the use of toad venom by ingestion or by sniffing in the United States and in Australia. This practice is not yet expanded in France. It is wished that toad venom doesn t take the relay to existent drugs, but on the opposite, it could be useful to discover other therapeutical interests.

  17. An introduced pentastomid parasite (Raillietiella frenata) infects native cane toads (Rhinella marina) in Panama.

    Science.gov (United States)

    Kelehear, Crystal; Saltonstall, Kristin; Torchin, Mark E

    2015-04-01

    The pentastomid parasite, Raillietiella frenata, is native to Asia where it infects the Asian House gecko, Hemidactylus frenatus. This gecko has been widely introduced and recently R. frenata was found in introduced populations of cane toads (Rhinella marina) in Australia, indicating a host-switch from introduced geckos to toads. Here we report non-native adult R. frenata infecting the lungs of native cane toads in Panama. Eight of 64 toads were infected (median = 2·5, range = 1-80 pentastomids/toad) and pentastomid prevalence was positively associated with the number of buildings at a site, though further sampling is needed to confirm this pattern. We postulate that this pattern is likely due to a host shift of this parasite from an urban-associated introduced gecko. This is the first record of this parasite infecting cane toads in their native range, and the first instance of this parasite occurring in Central America. PMID:25394910

  18. Hormone coexpression in the adult toad endocrine pancreas: double-label immunofluorescence under basal conditions and after glucose injection.

    Science.gov (United States)

    Luna, G; Francini, F; Gómez Dumm, C L; Madsen, O; Gagliardino, J J

    1999-07-01

    We have investigated the type and frequency of hormone coexpression in the endocrine pancreas of amphibians both under basal conditions and after sustained glucose loading. Adult male specimens of the wild toad Bufo arenarum were injected with a 50% (w/v) glucose solution (2 g/100 g) for 2 days, while control animals received an equal volume of the vehicle. Serum glucose levels were measured at the time of sacrifice and the pancreatic free lobe was processed for light microscopy. A double-labeling immunofluorescence study was performed for the detection of insulin (I), glucagon (G), somatostatin (S), and pancreatic polypeptide (PP). Heterospecific antisera against the following hormone combinations were used for their detection and immunocytochemical localization: I+G, I+PP, G+PP, S+G, and S+PP; visualization of the reacted IgG's was effected by fluorescein- and rhodamine-conjugated species-specific antibodies as fluorophores. Intracellular hormone coexpression was found to occur in the combinations G+PP, S+G, and S+PP. Moreover, glucose administration caused, together with a marked hyperglycemia (123 +/- 17 vs 23 +/- 1 mg/dl; P < 0.05), a decrease in the fraction of cells containing both G and PP together (from 106.3 +/- 8.1 to 26 +/- 4 cell/mm2) along with a reciprocal rise in the number of cells possessing G alone (from 128.7-152.3 to 235.9-274 cell/mm2). The fewer number of cells coexpressing either of the other two hormone combinations, however, were unaffected by glucose injection. With respect to the simultaneous measurement of I+G and I+PP, no cells were detected with both hormones of either pair, and the I-containing cells were more frequent in each instance in the control toads (264.8 +/- 22.3 to 269.2 +/- 27 cell/mm2). For both combinations, however, this value diminished significantly in the glucose-treated animals (108 +/- 2 cell/mm2 for I+G and 112.1 +/- 7. 8 cell/mm2 for I+PP). While the G-containing cells became more numerous (rising to 235.9 +/- 12.4, 274 +/- 26, and 250.4 +/- 23.7 cell/mm2 for I-G, G-PP, and G-S combinations, respectively), the PP- and S-containing cells remained unaffected. We conclude that the copresence of different hormones within the same cell is a relatively common finding in the non-I-secreting elements of the adult toad pancreas and that the proportions of specific cell types are affected by glucose administration. We thus propose that intracellular hormonal coexpression in this fashion may well represent a rapid and efficient regulatory mechanism for compensating for the metabolic stress imposed by glucose loading. PMID:10375461

  19. Effect of dietary fat on toad liver tumor induced by DMBA. Ultrastructural studies

    OpenAIRE

    I. A. Sadek; Abdul-Salarn, F.

    1994-01-01

    Toads injected with 2 mg 7,12-dimethylbenza( a)anthracene (DMBA)/toad, 3 timeslweek for 12 weeks induced liver tumors in 12 out of 50 cases. The electron micrograph of toad liver tumor showed disorganization of the rough endoplasmic reticulum which encircles or partially surrounds the mitochondria. Cristae mitochondrialis are rare in comparison with control. Enhancement of liver tumor incidences (29 out of 50 cases) by DMBA at the same dose level plus 2cc c...

  20. Invasive Cane Toads: Social Facilitation Depends upon an Individual’s Personality

    OpenAIRE

    González-Bernal, Edna; Brown, Gregory P.; Shine, Richard

    2014-01-01

    Individual variation in behavioural traits (including responses to social cues) may influence the success of invasive populations. We studied the relationship between sociality and personality in invasive cane toads (Rhinella marina) from a recently established population in tropical Australia. In our field experiments, we manipulated social cues (the presence of a feeding conspecific) near a food source. We captured and compared toads that only approached feeding sites where another toad was...

  1. Travelling waves for the cane toads equation with bounded traits

    International Nuclear Information System (INIS)

    In this paper, we study propagation in a non-local reaction–diffusion–mutation model describing the invasion of cane toads in Australia (Phillips et al 2006 Nature 439 803). The population of toads is structured by a space variable and a phenotypical trait and the space diffusivity depends on the trait. We use a Schauder topological degree argument for the construction of some travelling wave solutions of the model. The speed c* of the wave is obtained after solving a suitable spectral problem in the trait variable. An eigenvector arising from this eigenvalue problem gives the flavour of the profile at the edge of the front. The major difficulty is to obtain uniform L? bounds despite the combination of non-local terms and a heterogeneous diffusivity. (paper)

  2. Toad venom poisoning: resemblance to digoxin toxicity and therapeutic implications

    OpenAIRE

    Gowda, R M; Cohen, R. A.; Khan, I A

    2003-01-01

    A healthy man developed gastrointestinal symptoms after ingesting purported aphrodisiac pills. He had severe unrelenting bradycardia, hyperkalaemia, and acidosis. He rapidly developed severe life threatening cardiac arrhythmias and died after a few hours. He was found to have positive serum digoxin concentrations, although he was not taking digoxin. Toad venom poisoning is similar to digitalis toxicity and carries a high mortality. Cardiac glycoside poisoning can occur from ingestion of vario...

  3. Habitat use and movement of the endangered Arroyo Toad (Anaxyrus californicus) in coastal southern California

    Science.gov (United States)

    Gallegos, Elizabeth; Lyren, Lisa M.; Lovich, E. Robert; Mitrovich, Milan J.; Fisher, Robert N.

    2011-01-01

    Information on the habitat use and movement patterns of Arroyo Toads (Anaxyrus californicus) is limited. The temporal and spatial characteristics of terrestrial habitat use, especially as it relates to upland use in coastal areas of the species' range, are poorly understood. We present analyses of radiotelemetry data from 40 individual adult toads tracked at a single site in coastal southern California from March through November of 2004. We quantify adult Arroyo Toad habitat use and movements and interpret results in the context of their life history. We show concentrated activity by both male and female toads along stream terraces during and after breeding, and, although our fall sample size is low, the continued presence of adult toads in the floodplain through the late fall. Adult toads used open sandy flats with sparse vegetation. Home-range size and movement frequency varied as a function of body mass. Observed spatial patterns of movement and habitat use both during and outside of the breeding period as well as available climatological data suggest that overwintering of toads in floodplain habitats of near-coastal areas of southern California may be more common than previously considered. If adult toads are not migrating out of the floodplain at the close of the breeding season but instead overwinter on stream terraces in near-coastal areas, then current management practices that assume toad absence from floodplain habitats may be leaving adult toads over-wintering on stream terraces vulnerable to human disturbance during a time of year when Arroyo Toad mortality is potentially highest.

  4. Exploiting intraspecific competitive mechanisms to control invasive cane toads (Rhinella marina).

    Science.gov (United States)

    Crossland, Michael R; Haramura, Takashi; Salim, Angela A; Capon, Robert J; Shine, Richard

    2012-09-01

    If invasive species use chemical weapons to suppress the viability of conspecifics, we may be able to exploit those species-specific chemical cues for selective control of the invader. Cane toads (Rhinella marina) are spreading through tropical Australia, with negative effects on native species. The tadpoles of cane toads eliminate intraspecific competitors by locating and consuming newly laid eggs. Our laboratory trials show that tadpoles find those eggs by searching for the powerful bufadienolide toxins (especially, bufogenins) that toads use to deter predators. Using those toxins as bait, funnel-traps placed in natural waterbodies achieved near-complete eradication of cane toad tadpoles with minimal collateral damage (because most native (non-target) species are repelled by the toads' toxins). More generally, communication systems that have evolved for intraspecific conflict provide novel opportunities for invasive-species control. PMID:22696528

  5. Humoral immune alterations caused by lead: studies on an adult toad model Alteraciones inmunes humorales causadas por plomo: estudios en un modelo de sapo adulto

    Directory of Open Access Journals (Sweden)

    Carolina E. Rosenberg

    2007-07-01

    Full Text Available There is evidence that environmental metal levels affect the immune function. In the particular case of the impact of heavy metals, information available suggests that the immune system is a target for low-dose Pb exposure. Among vertebrates it was shown that amphibians are capable of forming antibodies against a variety of antigens, causing several responses such as anaphylactic response and rejecting grafts. In this study, the production of antibodies was assessed against sheep red blood cells (SRBC in the anuran Bufo arenarum after six weekly injections of sublethal doses of lead (50 mg.kg-1, as lead acetate. Natural antibodies (natural heteroagglutinins were also quantified against SRBC. Both assessments were carried out employing an ELISA method developed to this end, measuring absorbance (A. For natural anti-SRBC antibodies in both control (C and Pb treated (T toads, there was a non significant tendency to increase the initial absorbances (C initial: 0.69±0.39 A; T initial: 0.54±0.30 A, relative to those registered at the end of the experiments (C final: 0.89±0.49 A; T final: 0.76±0.31A; the T/C ratios also did not show changes. The only significant difference was found between initial and final samples from lead-treated toads (pExiste evidencia de que los niveles de metal ambientales afectan la función inmune. En el caso particular del impacto de metales pesados, la información disponible sugiere que el sistema inmune es un blanco para la exposición a bajas dosis de Pb. Entre los vertebrados, se ha mostrado que los anfibios son capaces de formar anticuerpos contra una variedad de antígenos, que causan diversas respuestas, tales como respuesta anafiláctica y rechazo de injertos. En este estudio, la producción de anticuerpos fue evaluada contra eritrocitos de oveja (EO en el anuro Bufo arenarum, luego de seis inyecciones semanales de dosis subletales de plomo (50 mg.kg-1, como acetato de Pb. Los anticuerpos naturales (heteroaglutininas naturales fueron también cuantificados contra EO. Ambas evaluaciones fueron llevadas a cabo empleando un método de ELISA desarrollado a este fin, midiendo la absorbancia (A. Para los anticuerpos anti-EO naturales, tanto en sapos controles (C como en sapos tratados con Pb (T, hubo una tendencia significativa a incrementar las absorbancias iniciales (C inicial: 0,69±0,39 A; T inicial: 0,54±0,30 A; la relación T/C tampoco mostró cambios. La única diferencia significativa se encontró entre las muestras inicial y final de los sapos tratados con plomo (p<0,014. Los niveles de anticuerpos anti-EO inmune de sapos inmunizados con EO mostraron un bajo incremento significativo (p<0,05 en los animales tratados con plomo (T final: 0,66±0,36 A, al compararse con sapos control (C final: 0,91±0,50 A al final del experimento. De este modo, se concluye que los cambios debidos a las dosis analizadas de Pb en los niveles de anticuerpos no pueden explicarse sólo sobre la base de un único mecanismo de acción del metal, sino como resultado de una conjunción de efectos sobre diferentes subpoblaciones de células inmunocompetentes. Estas diferentes respuestas sugieren que los factores que afectan los animales expuestos a un estímulo externo son diferentes de aquellos que influyen la respuesta en los animales silvestres.

  6. 2.MD Frog and Toad on the number line

    Science.gov (United States)

    This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: One day, Frog and Toad were sitting together on a lily pad. Some lily pads were in a line across the pond. In the morning, Frog hopped three lily pads ...

  7. Haematological changes in Bufo maculatus treated with sublethal concentrations of Cadmium

    OpenAIRE

    Alex Ajeh Enuneku; Lawrence Ikechukwu Ezemonye

    2011-01-01

    Adult Bufo maculatus was exposed to sublethal cadmium concentrations of 0.25, 0.50, 1.00 and 2.00 mg/L. The toxicant from which the cadmium concentrations were prepared was cadmium chloride (CdCl2.H2O). There were three replicate tanks per treatment and three individuals per tank including control groups. The hematologic alterations based on the examination of blood indices during the 28 days of exposure showed that total erythrocyte count (TEC), hematocrit (Hct) and hemoglobin (Hb) concentra...

  8. Portrait of a small population of boreal toads (Anaxyrus boreas)

    Science.gov (United States)

    Muths, Erin; Scherer, Rick D.

    2011-01-01

    Much attention has been given to the conservation of small populations, those that are small because of decline, and those that are naturally small. Small populations are of particular interest because ecological theory suggests that they are vulnerable to the deleterious effects of environmental, demographic, and genetic stochasticity as well as natural and human-induced catastrophes. However, testing theory and developing applicable conservation measures for small populations is hampered by sparse data. This lack of information is frequently driven by computational issues with small data sets that can be confounded by the impacts of stressors. We present estimates of demographic parameters from a small population of Boreal Toads (Anaxyrus boreas) that has been surveyed since 2001 by using capture-recapture methods. Estimates of annual adult survival probability are high relative to other Boreal Toad populations, whereas estimates of recruitment rate are low. Despite using simple models, clear patterns emerged from the analyses, suggesting that population size is constrained by low recruitment of adults and is declining slowly. These patterns provide insights that are useful in developing management directions for this small population, and this study serves as an example of the potential for small populations to yield robust and useful information despite sample size constraints.

  9. CAS role in the brain apoptosis of Bufo arenarum induced by Cypermethrin

    Scientific Electronic Library Online (English)

    M. F., Izaguirre; M. N., Vergara; V. H., Casco.

    2006-08-01

    Full Text Available CAS might have a key role in the apoptosis induced by toxins, acting as anti-apoptotic factor, stimulating the cellular proliferation and the cell contact stabilization. To start to elucidate their role in the brain apoptosis of Bufo arenarum induced by cypermethrin (CY), the expression patterns of [...] CAS and several cell adhesion molecules (CAMs) were established. Bufo arenarum tadpoles of the control and acute bioassay survival at different doses (39, 156, 625 and 2,500 µg CY/L) and times (24, 48, 72 and 96 h) of CY treatment were fixed in Carnoy, embedded in paraffin and sectioned. CAS and CAMs expression was determined by immunofluorescence and immunohistochemistry, respectively. When the bioassay starts, CAS increases suggesting a proliferative or regenerative effect, but decreases when the doses and/or the biocide exposure time increases, suggesting compromise of the cellular cycle control and trigger of an apoptotic wave. However, these neurotoxic mechanisms should not involve degradation of N-cadherin and ?-catenin, in contrast of ?-catenin and axonal N-CAM180, at least in the initial apoptotic phase. Additionally, an adhesion compensatory mechanism by N-CAM180 is observed in the neuron cell body. These results suggest a dual role of CAS in the cellular cycle control during the CY-induced apoptosis: induction of cell proliferation and stabilization of the cell-cell junctions by modulating CAMs expression.

  10. CAS role in the brain apoptosis of Bufo arenarum induced by Cypermethrin

    Directory of Open Access Journals (Sweden)

    M. F. Izaguirre

    2006-08-01

    Full Text Available CAS might have a key role in the apoptosis induced by toxins, acting as anti-apoptotic factor, stimulating the cellular proliferation and the cell contact stabilization. To start to elucidate their role in the brain apoptosis of Bufo arenarum induced by cypermethrin (CY, the expression patterns of CAS and several cell adhesion molecules (CAMs were established. Bufo arenarum tadpoles of the control and acute bioassay survival at different doses (39, 156, 625 and 2,500 µg CY/L and times (24, 48, 72 and 96 h of CY treatment were fixed in Carnoy, embedded in paraffin and sectioned. CAS and CAMs expression was determined by immunofluorescence and immunohistochemistry, respectively. When the bioassay starts, CAS increases suggesting a proliferative or regenerative effect, but decreases when the doses and/or the biocide exposure time increases, suggesting compromise of the cellular cycle control and trigger of an apoptotic wave. However, these neurotoxic mechanisms should not involve degradation of N-cadherin and ?-catenin, in contrast of ?-catenin and axonal N-CAM180, at least in the initial apoptotic phase. Additionally, an adhesion compensatory mechanism by N-CAM180 is observed in the neuron cell body. These results suggest a dual role of CAS in the cellular cycle control during the CY-induced apoptosis: induction of cell proliferation and stabilization of the cell-cell junctions by modulating CAMs expression.

  11. Descripción de dos renacuajos y una clave para las larvas conocidas del grupo Bufo spinulosus (Anura: Bufonidae) de Perú / Description of two tadpoles and a key to the known larvae of the Bufo spinulosus group (Anura: Bufonidae) occurring in Peru

    Scientific Electronic Library Online (English)

    César, Aguilar; Rocío, Gamarra.

    2004-07-01

    Full Text Available Se describen los renacuajos de Bufo arequipensis y Bufo cophotis. Ningún carácter externo examinado permite distinguir la larva de las especies nominales B. arequipensis, B. flavolineatus y B. trifolium. La larva de Bufo limensis se diferencia de las de B. flavolineatus y B. trifolium por presentar [...] un espacio menor en la segunda fila anterior de dentículos labiales y una fórmula de dentículos labiales (LTRF) igual a 2(2)/3[1]. B. cophotis difiere de B. limensis, B. flavolineatus y B. trifolium por presentar la altura máxima de la cola en su extremo posterior, una coloración marrón oscura en el cuerpo y cola, y un LTRF igual a 2(2)/3(1). Se proporciona una clave de identificación para las larvas conocidas del grupo spinulosus presentes en Perú. Abstract in english The tadpoles of Bufo arequipensis and Bufo cophotis are described. No external larval character studied allowed the distinction between the tadpoles of the nominal species B. arequipensis, B. flavolineatus and B. trifolium. The tadpole of B. limensis differs from the ones of B. flavolineatus and B. [...] trifolium by the presence of a small gap in the second anterior tooth row and a 2(2)/3[1] labial tooth row formula (LTRF). The tadpole of B. cophotis differs from B. limensis, B. flavolineatus and B. trifolium larvae by showing the highest part of the tail in its posterior end, a dark brown coloration in the body and tail, and a 2(2)/3(1) LTRF. An identification key for the known Peruvian tadpoles of the spinulosus group is provided.

  12. Exploiting intraspecific competitive mechanisms to control invasive cane toads (Rhinella marina)

    OpenAIRE

    Crossland, Michael R.; Haramura, Takashi; Salim, Angela A.; Capon, Robert J.; Shine, Richard

    2012-01-01

    If invasive species use chemical weapons to suppress the viability of conspecifics, we may be able to exploit those species-specific chemical cues for selective control of the invader. Cane toads (Rhinella marina) are spreading through tropical Australia, with negative effects on native species. The tadpoles of cane toads eliminate intraspecific competitors by locating and consuming newly laid eggs. Our laboratory trials show that tadpoles find those eggs by searching for the powerful bufadie...

  13. Morphological and genetic differentiation among Chilean populations of Bufo spinulosus (Anura: Bufonidae Diferenciación morfológica y genética entre poblaciones chilenas de Bufo spinulosus (Anura: Bufonidae

    Directory of Open Access Journals (Sweden)

    Marco A. Méndez

    2004-09-01

    Full Text Available Bufo spinulosus has a wide and fragmented range distribution in Chile (18° to 33° S along altitudinal and latitudinal gradients. Genetic variation was estimated using RAPD (Random Amplified Polymorphic DNA markers in 10 populations from northern and central Chile. Morphometric and genetic information was analyzed as a function of geographical origin. The correlation between genetic and morphometric differentiation was analyzed by the Mantel test. An increase in body size as a function of latitude was observed. Specimens from El Tatio had the smallest body size and the greatest morphometric divergence. The AMOVA applied to genetic data indicated that 57.85 % of the variance is explained by interregional differences and that 30.12 % of the variance is found within populations. Low levels of within-regions genetic differentiation was observed in northern populations while higher levels of genetic differentiation was found in populations from central Chile. Mantel tests revealed a significant, positive correlation between genetic variation and geographic distance. When we excluded El Tatio population, Mantel test analyses showed significant correlations between morphological distance and genetic and geographic distances. We discuss whether water temperature could explain the morphological divergence observed in individuals from El TatioBufo spinulosus presenta una amplia y fragmentada distribución en Chile (18º a 33º S a lo largo de gradientes altitudinales y latitudinales. La variación genética fue estimada utilizando marcadores RAPD ("Random Amplified Polymorphic DNA" en diez poblaciones del norte y centro de Chile. La información morfométrica y genética fue analizada en función de la procedencia geográfica. La correlación entre diferenciación genética y morfométrica fue analizada utilizando la prueba de Mantel. Se observó un incremento en el tamaño corporal en función de la latitud. Los individuos de El Tatio mostraron el tamaño corporal más pequeño y la mayor divergencia morfométrica. El AMOVA aplicado a los datos genéticos indicó que el 57.85 % de la varianza es explicada por diferencias entre regiones y que el 30.12 % de la varianza se encuentra dentro de las poblaciones. Bajos niveles de diferenciación genética intraregional fueron observados en las poblaciones del norte de Chile, mientras que las poblaciones de Chile central mostraron niveles más altos de diferenciación genética. Las pruebas de Mantel revelaron una correlación significativa y positiva entre la variación genética y la distancia geográfica. Cuando excluimos la población de El Tatio, las pruebas de Mantel mostraron correlaciones positivas y significativas entre las distancias morfológicas, genéticas y geográficas. Se discute si la temperatura del agua podría explicar la divergencia morfológica observada en los individuos de El Tatio

  14. The All Optical New Universal Gate Using TOAD

    Directory of Open Access Journals (Sweden)

    Goutam Kumar Maity

    2014-06-01

    Full Text Available Since the seventies of the past century the reversible logic has originated as an unconventional form of computing. It is new relatively in the area of extensive applications in quantum computing, low power CMOS, DNA computing, digital signal processing (DSP, nanotechnology, communication, optical computing, computer graphics, bio information, etc .Here we present and configure a new TAND gate in all-optical domain and also in this paper we have explained their principle of operations and used a theoretical model to fulfil this task, finally supporting through numerical simulations. In the field of ultra-fast all-optical signal processing Terahertz Optical Asymmetric Demultiplexer (TOAD, semiconductor optical amplifier (SOA-based, has an important function. The different logical (composing of Boolean function operations can be executed by designed circuits with TAND gate in the domain of universal logic-based information processing.

  15. Alimentación y fecundidad de Bufo variegatus (Anura: Bufonidae en Santa Cruz, Argentina

    Directory of Open Access Journals (Sweden)

    Rappi, Guillermina E.

    2000-04-01

    Full Text Available Se describe la alimentación de una población de Bufo variegatus procedente de la región de Lago del Desierto, provincia de Santa Cruz, Argentina. De los 11 ítems presa identificados, los más consumidos por los adultos (tanto machos como hembras fueron los coleópteros. En los machos la segunda categoría presa mas importante en la contribución a la dieta fueron los ácaros, mientras que en las hembras las hormigas y las larvas de insectos siguieron en importancia al consumo de coleópteros. En los especímenes juveniles, los ácaros fueron las presas más consumidas, quedando los coleópteros en segundo lugar en importancia relativa. Se demuestra la existencia de una correlación positiva significativa entre el volumen de las presas y el tamaño del depredador. Se aportan datos referentes a la fecundidad de B. variegatus y se comprueba la ausencia de correlación entre el tamaño de las hembras grávidas y el número de óvulos maduros. The diet of a population of Bufo variegatus from the region of Lago del Desierto, Santa Cruz province, Argentina, is described. Of the 11 prey items identified, Coleoptera was the most consumed prey both for males and females. In males, the second most important prey was Acarii, while in females they were the ants and insect larvae. Acarii was the most consumed prey for juveniles, followed by Coleoptera. A significant positive correlation was found between prey volume and predator body size. Fecundity information for B. variegwus is given, and a lack of correlation between snout-vent length of mature females and ovarian egg complement is demonstrated.

  16. Acclimation to Low Level Exposure of Copper in Bufo arenarum Embryos: Linkage of Effects to Tissue Residues

    Directory of Open Access Journals (Sweden)

    Cristina Silvia Pérez-Coll

    2007-06-01

    Full Text Available The acclimation possibilities to copper in Bufo arenarum embryos was evaluated by means of three different low level copper exposure conditions during 14 days. By the end of the acclimation period the copper content in control embryos was 1.04 ± 0.09 μg.g-1 (wet weight while in all the acclimated embryos a reduction of about 25% of copper was found. Thus copper content could be considered as a biomarker of low level exposure conditions. Batches of 10 embryos (by triplicate from each acclimation condition were challenged with three different toxic concentrations of copper. As a general pattern, the acclimation protocol to copper exerted a transient beneficial effect on the survival of the Bufo arenarum embryos. The acclimation phenomenon could be related to the selection of pollution tolerant organisms within an adaptive process and therefore the persistence of information within an ecological system following a toxicological stressor.

  17. Effect of Corn Oil on Liver Glycogen Content and Blood Glucose-6-phosphatase Dehydrogenase in Toads Treated with DMBA

    Directory of Open Access Journals (Sweden)

    N.E. Abdelmeguid

    2000-01-01

    Full Text Available Environmental factors play an important role in the etiology of several types of cancer, this discovery has led to a great deal of interest in the role of diet in cancer etiology. Fed the Egyptian toad with 0.5 ml corn oil and 0.2 mg DMBA toad/3, 3 times/week increased the incidence of liver tumor (22 out of 50 cases in comparison with toads treated with DMBA alone (16 out of 50 cases. On the ultrastructural level, corn oil increased (a the depletion of glycogen, (b accumulation of fat and lysosomes in toad liver tumor. The biochemical data indicated that glucose-6 phosphatase dehydrogenase in the blood, acid and alkaline phosphatase enzymes activities were increased in serum of toads treated with DMBA and corn oil than animals treated with DMBA alone.

  18. Stage dependent acute toxicity of exposure of Bufo maculatus and Ptychadena bibroni tadpoles to cadmium (Cd2)

    International Nuclear Information System (INIS)

    Tadpoles of Bufo maculatus and Ptychadena bibroni were exposed to five concentrations of Cadmium (Cd2+) (0.1, 0.15, 0.2, 0.25 and 0.5 ?g/L) at four life stages (7, 14, 21 and 28 days) after hatching. Two replicate tanks with 20 tadpoles per replicate were used for the study. Percentage mortality increased with increase in concentration of Cd2+ and exposure time, but decreased as maturation stage increased. Derived 96 h lethal median count (LC50) values increased with increase in maturation and ranged between 0.103 - 0.148 ?lg/L for Bufo maculatus and 0.126 - 0.159 ?lg/L for Ptychadena bibroni. Acute toxicity of Cd2+ was observed to be species specific. Tadpoles of Bufo maculatus were highly sensitive to Cd2+, while tadpoles of Ptychadena bibroni were observed to be better sentinels of Cd2+ due to the higher tolerance level exhibited. The four-week old larvae proved to be a better experimental material for ecotoxicological studies. Since the anuran larvae were sensitive to chemical stressors containing Cd, discharging effluents containing Cd2+ into aquatic ecosystem during amphibian breeding must be avoided. (au)

  19. Time-dependent aldosterone metabolism in toad urinary bladder

    International Nuclear Information System (INIS)

    Aldosterone (Aldo) metabolism was examined in the toad bladder. Bladders were incubated with [3H]aldosterone (10(-7) M) for 5 h, 1 h, or 10 min. Tissues were analyzed for metabolites using high-pressure liquid chromatography (HPLC). In separate experiments, Na+ transport was assessed by the short-circuit current (SCC) technique. Following a 5-h tissue incubation, about 25% of the [3H]-aldosterone was converted into metabolites including a polar monosulfate metabolite, 20 beta-dihydroaldo (20 beta-DHAldo), small quantities of 5 beta-reduced products, and a variety of 5 alpha-reduced Aldo products including 5 alpha-DHAldo, 3 alpha,5 alpha-tetrahydroaldo (3 alpha,5 alpha-THAldo), and 3 beta,5 alpha-THAldo. Tissues metabolized approximately 10% of the labeled hormone into the same compounds by 1 h. Measurable quantities of these metabolites were also synthesized by bladders exposed to Aldo for only 10 min and then incubated in buffer for an additional 50 min without Aldo. Bladders pretreated with the spironolactone, K+-canrenoate (3.5 X 10(-4) M), and stimulated with Aldo (10(-7) M) generated a peak SCC 44 +/- 6% of that observed in matched pairs stimulated with Aldo (P less than 0.001; n = 6). K+-canrenoate also markedly diminished [3H]aldosterone metabolism at both 5 and 1 h. Thus, metabolic transformation of Aldo begins prior to hormone-induced increases in Na+ transport. Both the generation of certain metabolites (e.g., 5 alpha-reductacertain metabolites (e.g., 5 alpha-reductase pathway products) and the increase in Na+ transport can be selectively inhibited by K+-canrenoate

  20. Photodynamic toxicity and its prevention by antioxidative agents in Bufo arenarum embryos

    International Nuclear Information System (INIS)

    In this work we describe an experimental model to evaluate the photodynamic toxicity on amphibian embryos, as well as the protective effect of antioxidants against the lethal oxidative stress induced by photosensitization. Bufo arenarum embryos were treated with 10 mg/l methylene blue (MB) in AMPHITOX solution for 72 h and then irradiated with a red laser or white light for variable times. Both light sources affected the survival of MB-treated animals and lethal effects occurred within the initial 12 h post-irradiation. For white light irradiation, the most effective phototoxic condition in our study, the LD10, 50 and 90 at 6 h post-irradiation corresponded to 13.57, 19.87 and 29.10 J/cm2, respectively. To explore the action of antioxidants against the photogenerated oxidative stress, MB-treated embryos were incubated with 1 mM glutathione (GSH) or ascorbic acid (AA) during 48 h before irradiation. For GSH and 21.6 J/cm2 irradiation, the survival increased from 20 to 90%, whereas 100% survival was achieved with AA even after 43.2 J/cm2 irradiation. These results indicate that both the lethal photodynamic effect and its prevention by antioxidants can be evaluated by means of a simple toxicity test employing amphibian embryos

  1. The uptake of 14C-glycine to Bufo vulgaris formosus (Boulenger) larva at metamorphosis

    International Nuclear Information System (INIS)

    With the eggs of Bufo vulgaris formosus (Boulenger) immediately after fertilization, the larvae in the 50 ml solution containing 1 ml of 14C-glycine were developed to the end of metamorphosis. Measurements were made on the length of body, tail, fore limb and hind leg through the stages of tail degeneration and vestige. The radioactivity of the cut off fore limbs, hind legs, tails and head trunks was measured with a scintillation counter, and the 10 ? sections of the samples were used for autoradiography. The larvae uptook orally 14C-glycine to the organs of cell tissues. On the basis of the reports of the autolysis of tails and the activation of lysosome enzyme in metamorphosis and on the uptake of 14C-leucine and 14C-proline to four legs by other workers, and on the present results, the free amino acids formed from the autolysis of tails were utilized for the recomposition of organ protein synthesis in the metamorphosis of the amphibians. (J.P.N.)

  2. Expression of phosphatidylcholine biosynthetic enzymes during early embryogenesis in the amphibian Bufo arenarum.

    Science.gov (United States)

    Fernández-Bussy, Rodrigo; Mouguelar, Valeria; Banchio, Claudia; Coux, Gabriela

    2015-04-01

    In the principal route of phosphatidylcholine (PC) synthesis the regulatory steps are catalysed by CTP:phosphocholine cytidylyltransferase (CCT) and choline kinase (CK). Knock-out mice in Pcyt1a (CCT gene) and Chka1 (CK gene) resulted in preimplantation embryonic lethality, demonstrating the essential role of this pathway. However, there is still a lack of detailed CCT and CK expression analysis during development. The aim of the current work was to study the expression during early development of both enzymes in the external-fertilization vertebrate Bufo arenarum. Reverse transcription polymerase chain reaction (RT-PCR) and western blot confirmed their presence in unfertilized eggs. Analysis performed in total extracts from staged embryos showed constant protein levels of both enzymes until the 32-cell stage: then they decreased, reaching a minimum in the gastrula before starting to recover. CTP:phosphocholine cytidylyltransferase is an amphitropic enzyme that inter-converts between cytosolic inactive and membrane-bound active forms. Immunoblot analysis demonstrated that the cytosolic:total CCT protein ratio does not change throughout embryogenesis, suggesting a progressive decline of CCT activity in early development. However, PC (and phosphatidylethanolamine) content per egg/embryo remained constant throughout the stages analysed. In conclusion, the current data for B. arenarum suggest that net synthesis of PC mediated by CCT and CK is not required in early development and that supplies for membrane biosynthesis are fulfilled by lipids already present in the egg/embryo reservoirs. PMID:24229731

  3. The Effect of UV-B Radiation on Bufo arenarum Embryos Survival and Superoxide Dismutase Activity

    Directory of Open Access Journals (Sweden)

    O. Fridman

    2006-03-01

    Full Text Available The exposure of Bufo arenarum embryos to 300-310 nm UV-B at a dose of 4,104 Joule/m2 resulted in 100% lethality within 24 hr while 820 Joule/m2 was the NOEC value for short-term chronic (10 days exposure. The dose response curves show that lethal effects are proportional with the dose and achieve its highest value within 48 hr post exposure. The superoxide dismutase (SOD activity in amphibian embryos for sublethal UV-B exposures was evaluated by means of UV-B treatments with 273 (A, 820(B, 1368(C and 1915(D Joule/m2 at 2 and 5 hours post irradiation. The SOD activity in units/mg protein in A, B, C and D at 2 hr after treatments were 80.72 ± 14.29, 74.5 ± 13.19, 39.5 ± 6.99 and 10.7 ± 1.89 respectively while for control embryos it was 10.88 ± 1.31. At 5 hr after treatments the SOD values were similar to those found in control embryos. The results confirm the high susceptibility of amphibian embryos to UV-B and point out that the SOD activity is enhanced by low doses of UV-B irradiation achieving significantly higher values than in control embryos at 2 hr post exposure.

  4. Effect of Corn Oil on Liver Glycogen Content and Blood Glucose-6-phosphatase Dehydrogenase in Toads Treated with DMBA

    OpenAIRE

    N. E. Abdelmeguid; I. A. Sadek; J. M. Sorour; A.A. Attia

    2000-01-01

    Environmental factors play an important role in the etiology of several types of cancer, this discovery has led to a great deal of interest in the role of diet in cancer etiology. Fed the Egyptian toad with 0.5 ml corn oil and 0.2 mg DMBA toad/3, 3 times/week increased the incidence of liver tumor (22 out of 50 cases) in comparison with toads treated with DMBA alone (16 out of 50 cases). On the ultrastructural level, corn oil increased (a) the depletion of glycogen, (b) accumulation of fat an...

  5. Curcumin and its Effect on Cytochrome P450 and GST in Toad Liver Tumor Induced by DMBA

    OpenAIRE

    H. Abdel-Latif; I. A. Sadek

    1999-01-01

    Curcumin has been used as a colouring agent and spice in many food. The present results clearly demonstrated that toads received 0.5 mg curcumin and 0.5 mg DMBA/toad, 3 times/week for 12 weeks, showed a significant decrease in tumor incidence (3 out of 50 cases) in comparison with that treated with DMBA alone (12 out of 50 cases). At the same time, curcumin reduce the activity of liver microsomal cytochrome P450s and cytosolic GTSS enzymes in toads previously treated with DMBA. The present da...

  6. Passive and active defense in toads: the parotoid macroglands in Rhinella marina and Rhaebo guttatus.

    Science.gov (United States)

    Mailho-Fontana, Pedro L; Antoniazzi, Marta M; Toledo, Luís F; Verdade, Vanessa K; Sciani, Juliana M; Barbaro, Katia C; Pimenta, Daniel C; Rodrigues, Miguel T; Jared, Carlos

    2014-02-01

    Amphibians have many skin poison glands used in passive defense, in which the aggressor causes its own poisoning when biting prey. In some amphibians the skin glands accumulate in certain regions forming macroglands, such as the parotoids of toads. We have discovered that the toad Rhaebo guttatus is able to squirt jets of poison towards the aggressor, contradicting the typical amphibian defense. We studied the R. guttatus chemical defense, comparing it with Rhinella marina, a sympatric species showing typical toad passive defense. We found that only in R. guttatus the parotoid is adhered to the scapula and do not have a calcified dermal layer. In addition, in this species, the plugs obstructing the glandular ducts are more fragile when compared to R. marina. As a consequence, the manual pressure necessary to extract the poison from the parotoid is twice as high in R. marina when compared to that used in R. guttatus. Compared to R. marina, the poison of R. guttatus is less lethal, induces edema and provokes nociception four times more intense. We concluded that the ability of R. guttatus to voluntary squirt poison is directly related to its stereotyped defensive behavior, together with the peculiar morphological characteristics of its parotoids. Since R. guttatus poison is practically not lethal, it is possibly directed to predators' learning, causing disturbing effects such as pain and edema. The unique mechanism of defense of R. guttatus may mistakenly justify the popular myth that toads, in general, squirt poison into people's eyes. PMID:24130001

  7. Delimiting genetic units in Neotropical toads under incomplete lineage sorting and hybridization

    OpenAIRE

    Thomé Maria Tereza C; Zamudio Kelly R; Haddad Célio F. B.; Alexandrino João

    2012-01-01

    Abstract Background Delimiting genetic units is useful to enhance taxonomic discovery and is often the first step toward understanding evolutionary mechanisms generating diversification. The six species within the Rhinella crucifer group of toads were defined under morphological criteria alone. Previous data suggest limited correspondence of these species to mitochondrial lineages, and morphological intergradation at transitions between forms suggests hybridization. Here we extensively sample...

  8. Effect of parathyroid hormone on transport by toad and turtle bladder

    International Nuclear Information System (INIS)

    The authors recently demonstrated that parathyroid hormone (PTH) inhibited both vasopressin- and cyclic AMP-stimulated water transport in the toad bladder. This was associated with an increase in calcium uptake by isolated epithelial cells. They postulated that PTH exerts its action on H2O transport by directly stimulating calcium uptake. The current study was designed to compare the effects of PTH and the calcium ionophore, A23187, on H2O and Na transport and H? secretion in toad and turtle bladders. In toad bladder, PTH and A23187 decreased arginine vasopressin (AVP)-stimulated H2O flow and short-circuit current (SCC) after 60 min serosal incubation. In turtle bladder A23187 decreased SCC to 79.3 +/- 3.6% of base line (P + secretion in turtle bladders. Both PTH and A23187 increased 45Ca uptake in toad bladder epithelial cells; only A23187 increased 45Ca uptake in the turtle bladder. The different action of PTH in these two membranes, compared with that of the calcium ionophore, illustrates the selectivity of PTH on membrane transport. PTH increases calcium uptake and decreases transport only in a hormone-sensitive epithelium, whereas the ionophore works in virtually all living membranes. The mode of action of these two agents to increase calcium uptake is, therefore likely differentt

  9. El ciclo evolutivo experimental de Diphyllobothrium erinaceieuropei en Paracyclops fimbriatus, larvas de Bufo arenarum y caninos / Experimental life cycle of Diphyllobothrium erinaceieuropei in Paracyclops fimbriatus, tadpoles of Bufo arenarum and dogs

    Scientific Electronic Library Online (English)

    Lucila, Venturini.

    1989-10-01

    Full Text Available El objetivo del trabajo fue lograr la reproducción experimental del ciclo evolutivo de Diphyllobothrium erinaceieuropei Rudolphi 1819 (Cestoda, Pseudophyllidea) con la intervención de Paracyclops fimbriatus y larvas de Bufo arenarum como hospedadores intermediarios y caninos como hospedadores defini [...] tivos. Los huevos del parásito se obtuvieron de heces de caninos infectados naturalmente y se conservaron refrigerados en agua. Se incubaron 7 días a 25°C para que desarrollaran los coracidios y se pusieron en recipientes que contenían a los copépodos mencionados. Al cabo de 12 días a 22,6°C (promedio) se hallaron procercoides maduros en ellos y se agregaron 10 renacuajos de Bufo arenarum. Estos se examinaron por disección 22, 23, 61 y 107 días después, hallándose en todos 1 o más plerocercoides (Temperatura promedio: 24,9°C). El día 23, de 6 renacuajos se obtuvieron 49 plerocercoides, de los cuales se administraron 28, por vía oral, a una perra. El día 107, 3 de 11 plerocercoides obtenidos de un renacuajo se le dieron a otra perra por la misma vía. Se hallaron huevos del cestode en las heces del primer canino a partir del día 22 posterior a la infección (p.i.) y a los 30 días p.i., segmentos de estróbila. En el segundo canino se hallaron huevos a los 30 días p.i.. Abstract in english Experiments were performed in order to develop the life cycle of Diphyllobothrium erinaceieuropei Rudolphi 1819 (Cestoda, Pseudophyllidea) in Paracyclops fimbriatus and Bufo arenarum as intermediate hosts and dogs as definitive hosts. The eggs of Diphyllobothrium erinaceieuropei from faeces of natur [...] ally infected dogs were kept refrigered, in water. In order to obtain coracidiums they were incubated at 25°C, and then were placed in a flask which contained Paracyclops fimbriatus. The copepods were observed to be infected with procercoids 12 days after, (mean temperature 22.6°C) and then, ten tadpoles of Bufo arenarum were put into the same flask. The tadpoles were examined 22, 23, 61 and 107 days later, finding plerocercoids in all them (mean temperature 24.9°C). On the 23th day, 49 plerocercoids were removed from 6 tadpoles and 28 of them were fed to a bitch. On the 107th day, 11 plerocercoids were recovered from a dead tadpole and 3 of them were fed to another bitch. In the faeces of the first bitch there were observed the eggs of Diphyllobothrium erinaceieuropei 22 days post infection (d.p.i.) and part of the strobila 30 d.p.i.. In the faeces of the second bitch the eggs were found 30 d.p.i..

  10. El ciclo evolutivo experimental de Diphyllobothrium erinaceieuropei en Paracyclops fimbriatus, larvas de Bufo arenarum y caninos Experimental life cycle of Diphyllobothrium erinaceieuropei in Paracyclops fimbriatus, tadpoles of Bufo arenarum and dogs

    Directory of Open Access Journals (Sweden)

    Lucila Venturini

    1989-10-01

    Full Text Available El objetivo del trabajo fue lograr la reproducción experimental del ciclo evolutivo de Diphyllobothrium erinaceieuropei Rudolphi 1819 (Cestoda, Pseudophyllidea con la intervención de Paracyclops fimbriatus y larvas de Bufo arenarum como hospedadores intermediarios y caninos como hospedadores definitivos. Los huevos del parásito se obtuvieron de heces de caninos infectados naturalmente y se conservaron refrigerados en agua. Se incubaron 7 días a 25°C para que desarrollaran los coracidios y se pusieron en recipientes que contenían a los copépodos mencionados. Al cabo de 12 días a 22,6°C (promedio se hallaron procercoides maduros en ellos y se agregaron 10 renacuajos de Bufo arenarum. Estos se examinaron por disección 22, 23, 61 y 107 días después, hallándose en todos 1 o más plerocercoides (Temperatura promedio: 24,9°C. El día 23, de 6 renacuajos se obtuvieron 49 plerocercoides, de los cuales se administraron 28, por vía oral, a una perra. El día 107, 3 de 11 plerocercoides obtenidos de un renacuajo se le dieron a otra perra por la misma vía. Se hallaron huevos del cestode en las heces del primer canino a partir del día 22 posterior a la infección (p.i. y a los 30 días p.i., segmentos de estróbila. En el segundo canino se hallaron huevos a los 30 días p.i..Experiments were performed in order to develop the life cycle of Diphyllobothrium erinaceieuropei Rudolphi 1819 (Cestoda, Pseudophyllidea in Paracyclops fimbriatus and Bufo arenarum as intermediate hosts and dogs as definitive hosts. The eggs of Diphyllobothrium erinaceieuropei from faeces of naturally infected dogs were kept refrigered, in water. In order to obtain coracidiums they were incubated at 25°C, and then were placed in a flask which contained Paracyclops fimbriatus. The copepods were observed to be infected with procercoids 12 days after, (mean temperature 22.6°C and then, ten tadpoles of Bufo arenarum were put into the same flask. The tadpoles were examined 22, 23, 61 and 107 days later, finding plerocercoids in all them (mean temperature 24.9°C. On the 23th day, 49 plerocercoids were removed from 6 tadpoles and 28 of them were fed to a bitch. On the 107th day, 11 plerocercoids were recovered from a dead tadpole and 3 of them were fed to another bitch. In the faeces of the first bitch there were observed the eggs of Diphyllobothrium erinaceieuropei 22 days post infection (d.p.i. and part of the strobila 30 d.p.i.. In the faeces of the second bitch the eggs were found 30 d.p.i..

  11. Correction of locality records for the endangered arroyo toad (Anaxyrus californicus) from the desert region of southern California

    Science.gov (United States)

    Ervin, Edward L.; Beaman, Kent R.; Fisher, Robert N.

    2013-01-01

    The recovery strategy for an endangered species requires accurate knowledge of its distribution and geographic range. Although the best available information is used when developing a recovery plan, uncertainty often remains in regard to a species actual geographic extent. The arroyo toad (Anaxyrus californicus) occurs almost exclusively in coastal drainages, from Monterey County, California, south into northwestern Baja California, Mexico. Through field reconnaissance and the study of preserved museum specimens we determined that the four reported populations of the arroyo toad from the Sonoran Desert region of Riverside, San Diego, and Imperial counties, California are in error. Two additional sites in the Sonoran Desert are discussed regarding the possibility that the arroyo toad occurs there. We recommend the continued scrutiny of arroyo toad records to maintain a high level of accuracy of its distribution and geographic extent.

  12. Ion transport by mitochondria-rich cells in toad skin

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Ussing, H H

    1987-01-01

    The optical sectioning video imaging technique was used for measurements of the volume of mitochondria-rich (m.r.) cells of the isolated epithelium of toad skin. Under short-circuit conditions, cell volume decreased by about 14% in response to bilateral exposure to Cl-free (gluconate substitution) solutions, apical exposure to a sodium-free solution, or to amiloride. Serosal exposure to ouabain resulted in a large increase in volume, which could be prevented either by the simultaneous application of amiloride in the apical solution or by the exposure of the epithelium to bilateral Cl-free solutions. Unilateral exposure to a Cl-free solution did not prevent ouabain-induced cell swelling. It is concluded that m.r. cells have an amiloride-blockable Na conductance in the apical membrane, a ouabain-sensitive Na pump in the basolateral membrane, and a passive Cl permeability in both membranes. From the initial rate of ouabain-induced cell volume increase the active Na current carried by a single m.r. cell was estimated to be 9.9 +/- 1.3 pA. Voltage clamping of the preparation in the physiological range of potentials (0 to -100 mV, serosa grounded) resulted in a cell volume increase with a time course similar to that of the stimulation of the voltage-dependent Cl conductance. Volume increase and conductance activation were prevented by exposure of the tissue to a Cl-free apical solution. The steady-state volume of the m.r. cells increased with the clamping voltage, and at -100 mV the volume was about 1.15 times that under short-circuit conditions. The rate of volume increase during current passage was significantly decreased by lowering the serosal K concentration (Ki) to 0.5 mM, but was independent of whether Ki was 2.4, 5, or 10 mM. This indicates that the K conductance of the serosal membrane becomes rate limiting for the uptake of KCl when Ki is significantly lower than its physiological value. It is concluded that the voltage-activated Cl currents flow through the m.r. cells and that swelling is caused by an uptakeof Cl ions from the apical bath and K ions from the serosal bath. Bilateral exposure of the tissue to hypo- or hypertonic bathing solutions changed cell volume without detectable changes in the Cl conductance. The volume response to external osmotic perturbations followed that of an osmometer with an osmotically inactive volume of 21%.(ABSTRACT TRUNCATED AT 400 WORDS)

  13. Alkaloids from single skins of the Argentinian toad Melanophryniscus rubriventris (ANURA, BUFONIDAE): An unexpected variability in alkaloid profiles and a profusion of new structures

    OpenAIRE

    Garraffo, H. Martin; Andriamaharavo, Nirina R; Vaira, Marcos; María F. Quiroga; Cecilia HEIT; Spande, Thomas F

    2012-01-01

    GC-MS analysis of single-skins of ten Melanophryniscus rubriventris toads (five collections of two toads each) captured during their breeding season in NW Argentina has revealed a total of 127 alkaloids of which 56 had not been previously detected in any frog or toad. Included among these new alkaloids are 23 new diastereomers of previously reported alkaloids. What is particularly distinguishing about the alkaloid profiles of these ten collections is the occurrence of many of the alkaloids, w...

  14. Effects of oligomycin on transient currents carried by Na+ translocation of Bufo Na+/K(+)-ATPase expressed in Xenopus oocytes.

    Science.gov (United States)

    Ding, Yanli; Hao, Jingping; Rakowski, Robert F

    2011-10-01

    Na(+)/K(+)-ATPase (NKA) exports 3Na(+) and imports 2K(+) at the expense of the hydrolysis of 1ATP under physiological conditions. In the absence of K(+), it can mediate electroneutral Na(+)/Na(+) exchange. In the electroneutral Na(+)/Na(+) exchange mode, NKA produces a transient current containing fast, medium and slow components in response to a sudden voltage step. These three components of the transient current demonstrate the sequential release of Na(+) ions from three binding sites. Our data from oocytes provide further experimental support for the existence of these components. Oligomycin is an NKA inhibitor that favors the 2Na(+)-occluded state without affecting the conformational state of the NKA. We studied the effects of oligomycin on both K(+)-activated currents and transient currents in wild-type Bufo NKA and a mutant form of Bufo NKA, NKA: G813A. Oligomycin blocked almost all of the K(+)-activated current, although the three components of the transient current showed different sensitivities to oligomycin. The oligomycin-inhibited charge movement measured using a P/4 protocol had a rate coefficient similar to the medium transient component. The fast component of the transient current elicited by a short voltage step also showed sensitivity to oligomycin. However, the slow component was not totally inhibited by oligomycin. Our results indicate that the second and third sodium ions might be released to the extracellular medium by a mechanism that is not shared by the first sodium ion. PMID:21877177

  15. 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. ...

  16. All-Optical Terahertz Optical Asymmetric Demultiplexer (toad) Based Binary Comparator:. a Proposal

    Science.gov (United States)

    Chattopadhyay, Tanay

    Comparator determines whether a number is greater than, equals to or less than another number. It plays a significant role in fast central processing unit in all-optical scheme. In all-optical scheme here 1-bit binary comparator is proposed and described by Terahertz Optical Asymmetric Demultiplexer (TOAD) based interferometric switch. Simulation result by Mathcad-7 is also given. Cascading technique of building up the n-bit binary comparator with this 1-bit comparator block is also proposed here.

  17. Positive Darwinian selection results in resistance to cardioactive toxins in true toads (Anura: Bufonidae)

    OpenAIRE

    Moore, David J.; Halliday, Damien C. T.; David M. Rowell; Robinson, Anthony J.; Keogh, J. Scott

    2009-01-01

    Members of the Family Bufonidae, true toads, are famous for their endogenously synthesized cardioactive steroids that serve as defensive toxins. Evolution of resistance to these toxins is not understood. We sequenced a key region of the toxin's binding site in the Na+/K+ ATPase for relevant taxa representing Hyloidea (including bufonids), Ranoidea and Archaeobatrachia and tested for positive selection in a phylogenetic context. Bufonidae were distinct from other Hyloidea at 4–6 of 12 sites ...

  18. Integrating Multiple Distribution Models to Guide Conservation Efforts of an Endangered Toad.

    Science.gov (United States)

    Treglia, Michael L; Fisher, Robert N; Fitzgerald, Lee A

    2015-01-01

    Species distribution models are used for numerous purposes such as predicting changes in species' ranges and identifying biodiversity hotspots. Although implications of distribution models for conservation are often implicit, few studies use these tools explicitly to inform conservation efforts. Herein, we illustrate how multiple distribution models developed using distinct sets of environmental variables can be integrated to aid in identification sites for use in conservation. We focus on the endangered arroyo toad (Anaxyrus californicus), which relies on open, sandy streams and surrounding floodplains in southern California, USA, and northern Baja California, Mexico. Declines of the species are largely attributed to habitat degradation associated with vegetation encroachment, invasive predators, and altered hydrologic regimes. We had three main goals: 1) develop a model of potential habitat for arroyo toads, based on long-term environmental variables and all available locality data; 2) develop a model of the species' current habitat by incorporating recent remotely-sensed variables and only using recent locality data; and 3) integrate results of both models to identify sites that may be employed in conservation efforts. We used a machine learning technique, Random Forests, to develop the models, focused on riparian zones in southern California. We identified 14.37% and 10.50% of our study area as potential and current habitat for the arroyo toad, respectively. Generally, inclusion of remotely-sensed variables reduced modeled suitability of sites, thus many areas modeled as potential habitat were not modeled as current habitat. We propose such sites could be made suitable for arroyo toads through active management, increasing current habitat by up to 67.02%. Our general approach can be employed to guide conservation efforts of virtually any species with sufficient data necessary to develop appropriate distribution models. PMID:26125634

  19. Integrating Multiple Distribution Models to Guide Conservation Efforts of an Endangered Toad

    Science.gov (United States)

    Treglia, Michael L.; Fisher, Robert N.; Fitzgerald, Lee A.

    2015-01-01

    Species distribution models are used for numerous purposes such as predicting changes in species’ ranges and identifying biodiversity hotspots. Although implications of distribution models for conservation are often implicit, few studies use these tools explicitly to inform conservation efforts. Herein, we illustrate how multiple distribution models developed using distinct sets of environmental variables can be integrated to aid in identification sites for use in conservation. We focus on the endangered arroyo toad (Anaxyrus californicus), which relies on open, sandy streams and surrounding floodplains in southern California, USA, and northern Baja California, Mexico. Declines of the species are largely attributed to habitat degradation associated with vegetation encroachment, invasive predators, and altered hydrologic regimes. We had three main goals: 1) develop a model of potential habitat for arroyo toads, based on long-term environmental variables and all available locality data; 2) develop a model of the species’ current habitat by incorporating recent remotely-sensed variables and only using recent locality data; and 3) integrate results of both models to identify sites that may be employed in conservation efforts. We used a machine learning technique, Random Forests, to develop the models, focused on riparian zones in southern California. We identified 14.37% and 10.50% of our study area as potential and current habitat for the arroyo toad, respectively. Generally, inclusion of remotely-sensed variables reduced modeled suitability of sites, thus many areas modeled as potential habitat were not modeled as current habitat. We propose such sites could be made suitable for arroyo toads through active management, increasing current habitat by up to 67.02%. Our general approach can be employed to guide conservation efforts of virtually any species with sufficient data necessary to develop appropriate distribution models. PMID:26125634

  20. Arenobufagin, a compound in toad venom, blocks Na(+)-K+ pump current in cardiac myocytes.

    Science.gov (United States)

    Cruz, J dos S; Matsuda, H

    1993-08-01

    The effects of arenobufagin, a bufadienolide isolated from toad venom, on the Na+/K+ pump were investigated by recording the whole-cell current of dissociated cardiac myocytes. Arenobufagin blocked the Na+/K+ pump current in a dose-dependent manner with a half-maximal concentration of 0.29 microM and a Hill coefficient of 1.1. Arenobufagin is 3.5-fold more potent than ouabain. PMID:8223897

  1. Evolution of Rapid Development in Spadefoot Toads Is Unrelated to Arid Environments

    OpenAIRE

    Zeng, Ce; Go?mez-mestre, Iva?n; Wiens, John J.

    2014-01-01

    The extent to which species' life histories evolve to match climatic conditions is a critical question in evolutionary biology and ecology and as human activities rapidly modify global climate. GIS-based climatic data offer new opportunities to rigorously test this question. Superficially, the spadefoot toads of North America (Scaphiopodidae) seem to offer a classic example of adaptive life-history evolution: some species occur in extremely dry deserts and have evolved the shortest aquatic la...

  2. The interacting effects of ungulate hoofprints and predatory native ants on metamorph cane toads in tropical Australia.

    Science.gov (United States)

    Cabrera-Guzmán, Elisa; Crossland, Michael R; González-Bernal, Edna; Shine, Richard

    2013-01-01

    Many invasive species exploit the disturbed habitats created by human activities. Understanding the effects of habitat disturbance on invasion success, and how disturbance interacts with other factors (such as biotic resistance to the invaders from the native fauna) may suggest new ways to reduce invader viability. In tropical Australia, commercial livestock production can facilitate invasion by the cane toad (Rhinella marina), because hoofprints left by cattle and horses around waterbody margins provide distinctive (cool, moist) microhabitats; nevertheless the same microhabitat can inhibit the success of cane toads by increasing the risks of predation or drowning. Metamorph cane toads actively select hoofprints as retreat-sites to escape dangerous thermal and hydric conditions in the surrounding landscape. However, hoofprint geometry is important: in hoofprints with steep sides the young toads are more likely to be attacked by predatory ants (Iridomyrmex reburrus) and are more likely to drown following heavy rain. Thus, anthropogenic changes to the landscape interact with predation by native taxa to affect the ability of cane toads in this vulnerable life-history stage to thrive in the harsh abiotic conditions of tropical Australia. PMID:24255703

  3. Curcumin and its Effect on Cytochrome P450 and GST in Toad Liver Tumor Induced by DMBA

    Directory of Open Access Journals (Sweden)

    H. Abdel-Latif

    1999-01-01

    Full Text Available Curcumin has been used as a colouring agent and spice in many food. The present results clearly demonstrated that toads received 0.5 mg curcumin and 0.5 mg DMBA/toad, 3 times/week for 12 weeks, showed a significant decrease in tumor incidence (3 out of 50 cases in comparison with that treated with DMBA alone (12 out of 50 cases. At the same time, curcumin reduce the activity of liver microsomal cytochrome P450s and cytosolic GTSS enzymes in toads previously treated with DMBA. The present data suggest that curcumin decrease incidence of liver tumor in toads through inhibition of cytochrome P45O and GST activities. The present report was undertaken for two reasons. First to determine whether curcumin, which are widely used in food have anticarcinogenic effect on the liver of the Egyptian toad. Second, are curcumin effect on microsomal cytochrome P450 and GST activities to shed more light on the mechanisms (s of action.

  4. Activity patterns and fine-scale resource partitioning in the gregarious Kihansi spray toad Nectophrynoides asperginis in captivity.

    Science.gov (United States)

    Rija, Alfan A; Goboro, Ezekiel M; Mwamende, Kuruthumu A; Said, Abubakari; Kohi, Edward M; Hassan, Shombe N

    2014-01-01

    Understanding the behavior of species threatened with extinction is important for conservation planning and for solving problems facing species in captivity and the wild. We examined diurnal activity budgets and habitat use of the extinct in the wild Kihansi spray toad to provide insights into ongoing conservation initiatives for this species. Observations on eight target behaviors were made each morning and evening for 14 days, in two subpopulations at Kihansi and University of Dar es Salaam captive breeding centers. There were significantly more bouts of resting than calling, amplexing, hunting, walking, climbing, or feeding. There was no difference in mean time spent in each activity between the two subpopulations. The use of habitat was variable between age classes, subpopulations and sampling time. Young toads spent significantly more time resting at the top of vegetation and on walls while adults rested more on logs. Further, adults foraged more on the walls and vegetation in the morning and on the ground in the evening. Contrastingly, young toads foraged more on the ground in the morning and switched to elevated patches during evening. The similarity of the toads' behavior suggests that important biological traits are still maintained in captivity and retained across toad generations. Furthermore, temporal and spatial variations in the use of habitat structures between age groups suggest fine-scale resource partitioning to reduce competition in this gregarious species. These results highlight the importance of maintaining diverse habitat structures in captivity and are useful for planning species reintroduction and future restocking programs. PMID:25182839

  5. Antifungal effects of Ficus sycomorus and Pergularia tomentosa aqueous extracts on some organs in Bufo regularis treated with Aspergillus niger.

    Science.gov (United States)

    Bekheet, Souad H M; Abdel-Motaal, Fatma F; Mahalel, Usama A

    2011-12-01

    The antifungal efficacy of Ficus sycomorus and Pergularia tomentosa plant extracts on Bufo regularis experimentally infected with Aspergillus niger was studied. After an oral administration of the pathogen for 15 days, the blood, kidney and liver were examined. Treatment with A. niger produced a reduction in red blood count cells and hemoglobin content. Also, both livers and kidneys revealed marked destruction and degenerative changes. These changes included congestion of blood vessels, leukocytic infiltration, and cytoplasmic vacuolization of the hepatocytes. As well as complete destruction of the cellular boundaries of the tubular epithelia, inflammatory leukocytes between the intertubular spaces, destruction and necrosis in renal tubule cells and the swollen glomeruli with wide glomerular spaces were seen. Pretreatment with F. sycomorus and P. tomentosa plant extracts 1h prior the administration of A. niger for two weeks improved blood parameters and protected against hepatic and renal damage as observed from histological examination and reduced spore numbers in culture media on these organs. PMID:21996552

  6. Estudio morfométrico sobre el desarrollo y evolución de las glándulas tiroides durante la metamorfosis de Bufo arenarum

    Directory of Open Access Journals (Sweden)

    Miranda, Leandro Andrés

    1996-01-01

    Full Text Available Se ha estudiado el desarrollo y la evolución de las glándulas tiroideas durante la morfogénesis de Bufo arenarum. Usando diferentes parámetros morfométricos, hemos relacionado el crecimiento y desarrollo larval con el desarrollo de las glándulas tiroideas. Se observó que la longitud total, el peso de las larvas, el volumen glandular tiroideo y el diámetro folicular, aumentan hasta el estadio XV (fin de la prometamorfosis, mientras que el número de folículos y la altura de las células foliculares tiroideas se incrementan hasta el estadio XVII (mitad del clímax metamórfico. Todos estos parámetros disminuyeron considerablemente durante el clímax metamórfico mientras que en animales postmetamórficos se observó un incremento en los valores registrados. En base a los resultados obtenidos concluimos que hay un período de síntesis y almacenamiento de hormonas tiroideas durante el crecimiento larval y un segundo período caracterizado por la liberación de hormonas tiroideas hacia el final de la prometamorfosis y durante el clímax metamórfico. We studied the development and evolution of thyroid glands during Bufo arenarum morphogenesis. Using different morphometric parameters we related larval growth and metamorphosis with thyroid glands development We observed that total length, larval weight, thyroid gland volume and follicle diameter increased until stage XV (end of prometamorphosis, meanwhile the number of follicles and follicle cell height increased until stage XVII (midclimax. All these parameters decreased during metamorphic climax and an increase was observed in postmetamorphic animals. Our results lead us to conclude that during larval growth there is a period of synthesis and store of thyroid hormones. There is a second period characterized by thyroid hormones release during the end of prometamorphosis and metamorphic climax.

  7. The Acid Test: pH Tolerance of the Eggs and Larvae of the Invasive Cane Toad (Rhinella marina) in Southeastern Australia.

    Science.gov (United States)

    Wijethunga, Uditha; Greenlees, Matthew; Shine, Richard

    2015-01-01

    Invasive cane toads are colonizing southeastern Australia via a narrow coastal strip sandwiched between unsuitable areas (Pacific Ocean to the east, mountains to the west). Many of the available spawning sites exhibit abiotic conditions (e.g., temperature, salinity, and pH) more extreme than those encountered elsewhere in the toad's native or already invaded range. Will that challenge impede toad expansion? To answer that question, we measured pH in 35 ponds in northeastern New South Wales and 8 ponds in the Sydney region, in both areas where toads occur (and breed) and adjacent areas where toads are likely to invade, and conducted laboratory experiments to quantify effects of pH on the survival and development of toad eggs and larvae. Our field surveys revealed wide variation in pH (3.9-9.8) among natural water bodies. In the laboratory, the hatching success of eggs was increased at low pH (down to pH 4), whereas the survival, growth, and developmental rates of tadpoles were enhanced by higher pH levels. We found that pH influenced metamorph size and shape (relative head width, relative leg length) but not locomotor performance. The broad tolerance range of these early life-history stages suggests that pH conditions in ponds will not significantly slow the toad's expansion southward. Indeed, toads may benefit from transiently low pH conditions, and habitat where pH in wetlands is consistently low (such as coastal heath) may enhance rather than reduce toad reproductive success. A broad physiological tolerance during embryonic and larval life has contributed significantly to the cane toad's success as a widespread colonizer. PMID:26052640

  8. Mortalities of the Green Toad (Epidalea viridis (Laurenti, 1768 in Urban Environment: A Case Study from the City of Plovdiv

    Directory of Open Access Journals (Sweden)

    Miglena V. Valkanova

    2009-08-01

    Full Text Available The current study analyzes the types of mortalities of the green toad (Epidalea viridis in the city of Plovdiv. Among all recorded mortalities (n=42, the road kill was the most common cause of death (65 % of the cases, followed by killing by humans (usually children – 31%. Killing of green toads by dogs (2% and domestic cats (2% has the lowest impact. Both most significant factors (road kill and killing by humans affect mainly the adult specimens. No statistically significant difference between the mortalities of the two sexes was detected.

  9. The role of common toads in the winter diet of recolonising Eurasian otters (Lutra lutra

    Directory of Open Access Journals (Sweden)

    Pablo García-Díaz

    2011-02-01

    Full Text Available Importanza del rospo comune nella dieta invernale di una popolazione di lontra (Lutra lutra in espansione.
    Tramite analisi dei resti fecali, abbiamo evidenziato il ruolo fondamentale degli anfibi nella dieta invernale della lontra Lutra lutra in stagni artificiali della Spagna nord-occidentale. I numerosi “laghi di cava” presenti nell’area umida di Ribeiras do Louro e Gandaras de Budiño sono stati monitorati nel 2007-2009. Il rospo comune (Bufo bufo era la principale preda della lontra, costituendo l’88% della biomassa consumata, mentre il gambero americano Procambarus clarkii e i pesci erano prede secondarie. I nostri risultati contrastano con la ben nota preferenza della lontra per le rane rispetto al rospo. Il mantenimento della popolazione di lontra nel bacino del fiume Louro dipende strettamente dalla corretta gestione degli stagni artificiali.

  10. Light induces a rapid and transient increase in inositol-trisphosphate in toad rod outer segments

    International Nuclear Information System (INIS)

    The sub-second time course of changes in the content of [3H]inositol-1,4,5-trisphosphate was determined in rod outer segments from very rapidly frozen Bufo retinas that had been incubated with [3H]inositol. Rod outer segments were cut off frozen specimens with a cryostat microtome and the water soluble extracts were analyzed. The content of [3H]inositol-1,4,5-trisphosphate rose after approximately 250 msec of bright illumination, but returned to the unstimulated level after 1 sec, whether the stimulus remained on or not. That is, there was rapid but transient change in the content of [3H]inositol-1,4,5-trisphosphate after the onset of stimulation

  11. Assimilation efficiency in Bufo spinulosus tadpoles (Anura: Bufonidae: effects of temperature, diet quality and geographic origin Eficiencia de asimilación en larvas de Bufo spinulosus (Anura: Bufonidae: efecto de la temperatura, calidad de dieta y origen geográfico

    Directory of Open Access Journals (Sweden)

    A. GONZALO BENAVIDES

    2005-06-01

    Full Text Available The assimilation efficiency of Bufo spinulosus tadpoles from four localities in Chile was evaluated for two different temperatures (15 and 25 ºC and two different diets (low nutritional quality diet (LQD: 22.28 mg g N-1; high nutritional quality diet (HQD: 47.53 mg g N-1 using ash as a marker of digestion. Results showed that geographic origin did not affect assimilation efficiency, while the relationship observed between temperature and diet quality was significant. Assimilation efficiency was greater for the HQD when tadpoles were maintained at 15 °C, instead significant differences were not found between diets for tadpoles maintained at 25 °C. Our results suggest that the effect of temperature on digestive processes is more relevant than its effect on transit time in the digestive tract. The differences in size at metamorphosis in B spinulosus populations of distinct geographic origin could not be explained by the existence of differences in physiologic digestive capacitiesLa eficiencia de asimilación de materia en larvas de Bufo spinulosus provenientes de cuatro localidades de Chile, fue evaluada para dos temperaturas (15 y 25 ºC y dos dietas diferentes (pobre: 22,28 mg g N-1 y rica 47,53 mg g N-1, utilizando la ceniza cómo marcador de digestión. Los resultados mostraron que la localidad de origen de las larvas no afecta la eficiencia de asimilación, mientras que se registró una interacción significativa entre la temperatura y la calidad de la dieta. La eficiencia de asimilación es mayor para la dieta rica cuando las larvas fueron mantenidas a 15 °C, no existiendo diferencias entre dietas cuando fueron mantenidas a 25 °C. Nuestros resultados sugieren que para B. spinulosus el efecto de la temperatura sobre los procesos digestivos es más relevante que su efecto sobre el tiempo de tránsito en el tracto digestivo. Las diferencias en el tamaño alcanzado a la metamorfosis en poblaciones de B. spinulosus de origen geográfico distinto, no podrían ser explicadas por la existencia de diferencias en las capacidades fisiológicas digestivas

  12. Assimilation efficiency in Bufo spinulosus tadpoles (Anura: Bufonidae): effects of temperature, diet quality and geographic origin / Eficiencia de asimilación en larvas de Bufo spinulosus (Anura: Bufonidae): efecto de la temperatura, calidad de dieta y origen geográfico

    Scientific Electronic Library Online (English)

    A. GONZALO, BENAVIDES; ALBERTO, VELOSO; PAULINA, JIMÉNEZ; MARCO A., MÉNDEZ.

    2005-06-01

    Full Text Available La eficiencia de asimilación de materia en larvas de Bufo spinulosus provenientes de cuatro localidades de Chile, fue evaluada para dos temperaturas (15 y 25 ºC) y dos dietas diferentes (pobre: 22,28 mg g N-1 y rica 47,53 mg g N-1), utilizando la ceniza cómo marcador de digestión. Los resultados mos [...] traron que la localidad de origen de las larvas no afecta la eficiencia de asimilación, mientras que se registró una interacción significativa entre la temperatura y la calidad de la dieta. La eficiencia de asimilación es mayor para la dieta rica cuando las larvas fueron mantenidas a 15 °C, no existiendo diferencias entre dietas cuando fueron mantenidas a 25 °C. Nuestros resultados sugieren que para B. spinulosus el efecto de la temperatura sobre los procesos digestivos es más relevante que su efecto sobre el tiempo de tránsito en el tracto digestivo. Las diferencias en el tamaño alcanzado a la metamorfosis en poblaciones de B. spinulosus de origen geográfico distinto, no podrían ser explicadas por la existencia de diferencias en las capacidades fisiológicas digestivas Abstract in english The assimilation efficiency of Bufo spinulosus tadpoles from four localities in Chile was evaluated for two different temperatures (15 and 25 ºC) and two different diets (low nutritional quality diet (LQD): 22.28 mg g N-1; high nutritional quality diet (HQD): 47.53 mg g N-1) using ash as a marker of [...] digestion. Results showed that geographic origin did not affect assimilation efficiency, while the relationship observed between temperature and diet quality was significant. Assimilation efficiency was greater for the HQD when tadpoles were maintained at 15 °C, instead significant differences were not found between diets for tadpoles maintained at 25 °C. Our results suggest that the effect of temperature on digestive processes is more relevant than its effect on transit time in the digestive tract. The differences in size at metamorphosis in B spinulosus populations of distinct geographic origin could not be explained by the existence of differences in physiologic digestive capacities

  13. Modification of a prey catching response and the development of behavioral persistence in the fire-bellied toad (Bombina orientalis).

    Science.gov (United States)

    Ramsay, Zachary J; Ikura, Juntaro; Laberge, Frédéric

    2013-11-01

    The present report investigated how fire-bellied toads (Bombina orientalis) modified their response in a prey catching task in which the attribution of food reward was contingent on snapping toward a visual stimulus of moving prey displayed on a computer screen. Two experiments investigated modification of the snapping response, with different intervals between the opportunity to snap at the visual stimulus and reward administration. The snapping response of unpaired controls was decreased compared with the conditioned toads when hour or day intervals were used, but intervals of 5 min produced only minimal change in snapping. The determinants of extinction of the response toward the visual stimulus were then investigated in 3 experiments. The results of the first experiment suggested that increased resistance to extinction depended mostly on the number of training trials, not on partial reinforcement or the magnitude of reinforcement during training. This was confirmed in a second experiment showing that overtraining resulted in resistance to extinction, and that the pairing of the reward with a response toward the stimulus was necessary for that effect, as opposed to pairing reward solely with the experimental context. The last experiment showed that the time elapsed between training trials also influenced extinction, but only in toads that received few training trials. Overall, the results suggest that toads learning about a prey stimulus progress from an early flexible phase, when an action can be modified by its consequences, to an acquired habit characterized by an increasingly inflexible and automatic response. PMID:23668694

  14. Genetic attributes of midwife toad (Alytes obstetricans) populations do not correlate with degree of species decline.

    Science.gov (United States)

    Tobler, Ursina; Garner, Trenton W J; Schmidt, Benedikt R

    2013-09-01

    Genetic diversity is crucial for long-term population persistence. Population loss and subsequent reduction in migration rate among the most important processes that are expected to lead to a reduction in genetic diversity and an increase in genetic differentiation. While the theory behind this is well-developed, empirical evidence from wild populations is inconsistent. Using microsatellite markers, we compared the genetic structure of populations of an amphibian species, the midwife toad (Alytes obstetricans), in four Swiss regions where the species has suffered variable levels of subpopulation extirpation. We also quantified the effects of several geographic factors on genetic structure and used a model selection approach to ascertain which of the variables were important for explaining genetic variation. Although subpopulation pairwise F ST-values were highly significant even over small geographic scales, neither any of the geographic variables nor loss of subpopulations were important factors for predicting spatial genetic structure. The absence of a signature of subpopulation loss on genetic differentiation may suggest that midwife toad subpopulations function as relatively independent units. PMID:24101974

  15. [Determination of three bufogenins in toad venom using reversed-phase high performance liquid chromatography].

    Science.gov (United States)

    Liu, Jihua; Wang, Jingrong; Yu, Boyang

    2008-03-01

    A reversed-phase high performance liquid chromatographic method for the quantitative determination of three bufogenins in toad venom was established. An Alltech Alltima C18 column (250 mm x 4.6 mm, 5 microm) was used. The mobile phase was acetonitrile-0.1 mol/L acetate buffer (pH 3.2) (50:50, v/v), and the flow rate was 0.8 mL/min. The detection wavelength was set at 299 nm. The method has good linearity in the ranges of 0. 25 -0.875 microg for cinobufagin (r = 0.999 0), 0.25 -0.875 microg for resibufogenin (r = 0.999 1), and 0.15 - 0.525 microg for bufalin (r = 0. 999 0). The average recoveries were 100.3%, 100.0% and 98.0% for cinobufagin, resibufogenin, and bufalin, respectively. The results indicate that the method is simple, accurate, reproducible, and can be used for the quality control of bufogenins in toad venom. PMID:18581850

  16. Effects of intracellular sodium and potassium iontophoresis on membrane potentials and resistances in toad urinary bladder.

    Science.gov (United States)

    Narvarte, J; Finn, A L

    1985-01-01

    Glass microelectrodes were used to measure membrane potentials and the ratio of apical to basolateral membrane resistances before and after the passage of current from the potential-recording microelectrode to ground, in toad urinary bladder epithelium, in order to iontophorese cations into the cell. After application of the current, there was a transient change in the tip potential of the microelectrode. This artifact was measured with the microelectrode in the mucosal medium and was subtracted from the potential recorded in the cell. The serosal medium was bathed by Ringer's solution containing 51.5 mM K+ to minimize any current-induced increase of K+ in the unstirred layer. Under those conditions, both Na+ and K+ iontophoresis caused a significant hyperpolarization of basolateral membrane potential (Vcs) and a significant increase in the ratio of apical to basolateral membrane resistances (Ra/Rb). When bladders were exposed to amiloride in the mucosal solution, Na+ iontophoresis caused the basolateral membrane to hyperpolarize, but no significant changes were observed in Ra/Rb. When Na+ was injected in the presence of serosal ouabain, Vcs depolarized and Ra/Rb increased. K+ iontophoresis caused the basolateral membrane potential to hyperpolarize in the presence of ouabain but Ra/Rb did not change significantly. These results indicate that the Na+ pump in toad bladder is rheogenic, that apical Na+ conductance is sensitive to the cell levels of Na+ and K+ and that the basolateral membrane is K+ permeable. PMID:3923199

  17. Diffusion of 133Xe through frog skins, toad bladders, and water boundary layers

    International Nuclear Information System (INIS)

    We have measured the total permeability coefficients P as a function of stirring frequency ? for 133Xe through frog skins and toad bladders. The permeability coefficients for the frog skins and toad bladders proper are, respectively, P/sub m/ = (3.9 +- 0.8) x 10-4 cm/s and (7.4 +- 4.2) x 10-4 cm/s. ''Unstirred'' water layer thickness delta is determined concurrently, from the frequency dependence of P(?); the result for frog skin is delta = (0.060 +- 0.016)/??(rad/s) cm. The stirring frequency range is from ? = 7.5 rad/s (72 rpm) to 55 rad/s (530 rpm). The results support the conclusions that the principal barrier to Xe diffusion in these epithelia is inter- and intracellular water, and that the diffusion is passive and rapid. The experimental method may be straightforwardly adapted to the measurement of diffusion or counterdiffusion of any gamma-radioactive soluble or partly soluble solute through any flat membrane or through a solvent. We estimate the amount of total body-absorbed radioactivity due to environmental 133Xe to be 50 fCi for an ambient concentration of 2.6 pCi/m3 of air

  18. QUATERNARY DIVISION OPERATION BASED ON ALL- TERAHERTZ OPTICAL ASYMMETRIC DEMULTIPLEXER (TOAD

    Directory of Open Access Journals (Sweden)

    Alaa A. Al-Saffar

    2014-03-01

    Full Text Available Quaternary division based on all Terahertz Optical Asymmetric Demultiplexer (TOAD is proposed. It shows quaternary division operation based on discrete-detect zero circuit using T-gate. In this present work all optical scheme of the different quaternary logical states are represented by different polarized state of light. Introducing the discrete-detect zero circuit reduces the overall number of the T-gates in the division operation and the number of T-gate incoming data transmission lines to three. The design promises both higher processing speed and accuracy. The design can be evolution for more complex optical circuits of enhanced functionality in which the T-gate is the basic building block. The principles and possibilities of design of alloptical quaternary division circuits are proposed and described through numerical simulation.

  19. Membrane potential plays a dual role for chloride transport across toad skin

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Rasmussen, B E

    1983-01-01

    The Cl- -current through toad skin epithelium depends on the potential in a way consistent with a potential-controlled Cl- permeability. Computer analysis of the Koefoed-Johnsen Ussing two-membrane model provided with constant membrane permeabilities indicates that the voltage- and time-dependent currents are not caused by a trivial Goldmand-type rectification and ion redistributions following transepithelial potential pertubations. Extended with a dynamic Cl- permeability in the apical membrane according to a Hodgkin-Huxley kinetic scheme, the model predicts voltage clamp data which closely resemble experimental observations. This extension of the classic frog skin model implies that the Cl- permeability is activated by a voltage change caused by the inward Na+ current through the apical membrane.

  20. Nux Vomica 200 CH reduced acute hypnotic effect of alcohol in young toads

    Directory of Open Access Journals (Sweden)

    Nirmal Sukul

    2012-09-01

    Full Text Available Potentized Nux Vomica has been reported to produce antialcoholic effect in mice, rats and toads. The effect relates to consumption of alcohol and alcohol-induced loss of righting reflex (RR. RR’s maintain normal erect posture of an animal and are centrally controlled in the midbrain. In the present study young toads, Duttaphrynus melanostictus were first treated with Nux vomica 200 CH and then partially immersed in 209 mM ethanol solution in such a way that their head remained above the level of ethanol solution. Toadlets were removed from the ethanol solution every 10 min, tested for the loss of RR and returned to the ethanol solution. Toadlets were placed in a supine position on a dry flat surface. Failure to right within 60 sec was considered as the loss of RR. The experiment was repeated 10 times. Control toadlets were pretreated with 90% ethanol instead of Nux Vomica 200 CH. The percentages of toadlets showing loss of RR, both in the control as well as in the Nux-treated groups, were shown in graphs against the duration of exposure to ethanol solution. Differences in the percentage distribution between the control and the treatment groups losing RR were tested by χ2 test. All the experiments were conducted at room temperature. The percentage of toadlets losing RR increased with time of exposure to ethanol solution. The increase was significantly higher with the control than with the Nux-treated group. Nux Vomica 200 CH might have influenced the mid-brain of toadlets thereby countering the hypnotic effect of ethanol in the toadlets.

  1. Bm-TFF2, a toad trefoil factor, promotes cell migration, survival and wound healing

    International Nuclear Information System (INIS)

    Research highlights: ? Bm-TFF2 binds to epithelial cells and induces cell migration and wound healing. ? Bm-TFF2 suppresses cell apoptosis. ? Bm-TFF2 has no effect on cell proliferation. -- Abstract: Toad skin is naked and continually confronted by various injurious factors. Constant skin renewal and repairs occur frequently. However, the mechanisms of the renewal and repair have not clearly elucidated. In our previous work, a trefoil factor (TFF), Bm-TFF2, has been purified from the Bombina maxima skin and characterized as a platelet agonist. The mRNA of TFFs in toad skin was up-regulated greatly during the metamorphosis, indicating a pivotal role of TFFs in amphibian skin. Here, we presented the effects of Bm-TFF2 on the cell migration, apoptosis and proliferation. Bm-TFF2 bound to epithelial cells and showed strong cell motility activity. At the concentrations of 1-100 nM, Bm-TFF2-induced migration of human epithelial AGS and HT-29 cells, and rat intestinal epithelial IEC-6 cell lines. The in vitro wound healing assay also verified the activity of Bm-TFF2. Bm-TFF2 could also inhibit cell apoptosis induced by ceramide and sodium butyrate. The cell migration-promoting activity was abolished by MEK1 inhibitors, U0126 and PD98059, suggesting that ERK1/2 activation is crucial for Bm-TFF2 to stimulate cell migration. Taken together, Bm-TFF2 promoted wound healing by stimulating cell migration via MAPK pathway and preventing cell apoptosis. The potent biological activity of Bm-TFF2 makes it a useful molecular tool for further studies of structure-function relationship of the related human TFFs.

  2. Bm-TFF2, a toad trefoil factor, promotes cell migration, survival and wound healing

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yong [Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Yu, Guoyu [Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Department of Biochemistry, Kunming Medical College, Kunming, Yunnan 650032 (China); Xiang, Yang [Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Wu, Jianbo [Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223 (China); Jiang, Ping [Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Lee, Wenhui [Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223 (China); Zhang, Yun, E-mail: zhangy@mail.kiz.ac.cn [Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223 (China)

    2010-07-30

    Research highlights: {yields} Bm-TFF2 binds to epithelial cells and induces cell migration and wound healing. {yields} Bm-TFF2 suppresses cell apoptosis. {yields} Bm-TFF2 has no effect on cell proliferation. -- Abstract: Toad skin is naked and continually confronted by various injurious factors. Constant skin renewal and repairs occur frequently. However, the mechanisms of the renewal and repair have not clearly elucidated. In our previous work, a trefoil factor (TFF), Bm-TFF2, has been purified from the Bombina maxima skin and characterized as a platelet agonist. The mRNA of TFFs in toad skin was up-regulated greatly during the metamorphosis, indicating a pivotal role of TFFs in amphibian skin. Here, we presented the effects of Bm-TFF2 on the cell migration, apoptosis and proliferation. Bm-TFF2 bound to epithelial cells and showed strong cell motility activity. At the concentrations of 1-100 nM, Bm-TFF2-induced migration of human epithelial AGS and HT-29 cells, and rat intestinal epithelial IEC-6 cell lines. The in vitro wound healing assay also verified the activity of Bm-TFF2. Bm-TFF2 could also inhibit cell apoptosis induced by ceramide and sodium butyrate. The cell migration-promoting activity was abolished by MEK1 inhibitors, U0126 and PD98059, suggesting that ERK1/2 activation is crucial for Bm-TFF2 to stimulate cell migration. Taken together, Bm-TFF2 promoted wound healing by stimulating cell migration via MAPK pathway and preventing cell apoptosis. The potent biological activity of Bm-TFF2 makes it a useful molecular tool for further studies of structure-function relationship of the related human TFFs.

  3. Checklist and Simple Identification Key for Frogs and Toads from District IV of The MADA Scheme, Kedah, Malaysia

    OpenAIRE

    Jaafar, Ibrahim; Chai, Teoh Chia; Sah, Shahrul Anuar Mohd; Akil, Mohd Abdul Muin Md

    2009-01-01

    A survey was conducted to catalogue the diversity of anurans in District IV of the Muda Agriculture Development Authority Scheme (MADA) in Kedah Darul Aman, Malaysia, from July 1996 to January 1997. Eight species of anurans from three families were present in the study area. Of these, the Common Grass Frog (Fejevarya limnocharis) was the most abundant, followed by Mangrove Frog (Fejevarya cancrivora), Long-legged Frog (Hylarana macrodactyla), and Common Toad (Duttaphrynus melanostictus). Pudd...

  4. Introduction pathway and climate trump ecology and life history as predictors of establishment success in alien frogs and toads

    OpenAIRE

    Rago, A.; While, Gm; Uller, T.

    2012-01-01

    A major goal for ecology and evolution is to understand how abiotic and biotic factors shape patterns of biological diversity. Here, we show that variation in establishment success of nonnative frogs and toads is primarily explained by variation in introduction pathways and climatic similarity between the native range and introduction locality, with minor contributions from phylogeny, species ecology, and life history. This finding contrasts with recent evidence that particular species charac...

  5. The Interacting Effects of Ungulate Hoofprints and Predatory Native Ants on Metamorph Cane Toads in Tropical Australia

    OpenAIRE

    Cabrera-Guzmán, Elisa; Crossland, Michael R.; González-Bernal, Edna; Shine, Richard

    2013-01-01

    Many invasive species exploit the disturbed habitats created by human activities. Understanding the effects of habitat disturbance on invasion success, and how disturbance interacts with other factors (such as biotic resistance to the invaders from the native fauna) may suggest new ways to reduce invader viability. In tropical Australia, commercial livestock production can facilitate invasion by the cane toad (Rhinella marina), because hoofprints left by cattle and horses around waterbody mar...

  6. Effects of acute low temperature stress on the endocrine reactions of the Qinghai toad-headed lizard

    Directory of Open Access Journals (Sweden)

    Chunwang LI, Yuan GU, Songhua TANG, Hongxia FANG, Guohua JIANG, Zhigang JIANG

    2011-12-01

    Full Text Available Endocrinological action is generally thought to be a way for animals to respond to stress at low temperatures. To learn the role of hormones in ectotherms inhabiting alpine environments, we studied the effects of acute low temperature exposure on the endocrinological reactions of Qinghai toad-headed lizards in the Qinghai-Tibetan Plateau. We monitored plasma corticosterone and insulin concentration of the lizards under five low temperature treatments. We found no significant difference in plasma corticosterone or insulin in lizards among our five different treatments. For males and females the correlation between plasma corticosterone and insulin concentrations was not significant. In contrast to other studies on reptiles at low altitude, we suggest that due to the alpine environment (low temperature and low oxygen concentration they inhabit, Qinghai toad-headed lizards respond to experimental cold stress slightly to mobilize energy and live their vivid life. In addition, corticosterone and insulin of Qinghai toad-headed lizards are secreted independently along with low temperature treatments [Current Zoology 57 (6: 775–780, 2011].

  7. Effects of internal and external pH on amiloride-blockable Na+ transport across toad urinary bladder vesicles

    International Nuclear Information System (INIS)

    The authors have examined the effect of internal and external pH on Na+ transport across toad bladder membrane vesicles. Of the total 22Na uptake measured 0.5-2.0 min after introducing tracer, 80 +/- 4% (mean +/- SE, n = 9) is blocked by the diuretic with a KI of 2 X 10(-8) M. Thus, this amiloride-sensitive flux is mediated by the apical sodium-selective channels. Varying the internal (cytosolic) pH over the physiologic range 7.0-8.0 had no effect on sodium transport; this result suggests that variation of intracellular pH in vivo has no direct apical effect on modulating sodium uptake. On the other hand, 22Na was directly and monotonically dependent on external pH. External acidification also reduced the amiloride-sensitive efflux across the walls of the vesicles. This inhibition of 22Na efflux was noted at external Na+ concentrations of both 0.2 microM and 53 mM. These results are different from those reported with whole toad bladder. A number of possible bases for these differences are considered and discussed. They suggest that the natriferic response induced by mucosal acidification of whole toad urinary bladder appears to operate indirectly through one or more factors, presumably cytosolic, present in whole cells and absent from the vesicles

  8. Toddia sp., "corpúsculo paranuclear" no sangue de Leptodactylus e Bufo do Brasil: desenvolvimento e citoquímica Toddia sp. a paranuclear corpuscle in the blood of Leptodactylus and Bufo of Brazil

    Directory of Open Access Journals (Sweden)

    Neize de Moura Pereira

    1973-01-01

    Full Text Available O gênero Toddia, criado por França 1911, para um organismo encontrado em eritrõcitos de um anfíbio anuro, tem estrutura particular e o problema de sua natureza (protozoário ou vírus é discutido. Nosso resultados mostram reações Feulgen e Verde Metila positivas, principalmente no início da infecção. Com o decorrer da infecção as partículas são, geralmente, maiores que aquelas observadas alguns dias após as inoculações, mas as reações citoquímicas citadas anteriormente são, em geral, negativas ou fracamente positivas. Os mesmos resultados foram obtidos quando empregamos Laranja de acridina para caracterização do DNA e esta técnica foi negativa para o RNA. Estudando o desenvolvimento deste organismo e seus efeitos infecciosos foram confirmados por inoculações experimentais. As alterações no sangue do hospedeiro foram observadas e notamos que o núclo dos eritrócitos é severamente alterado durante o desenvolvimento da infecção, que é geralmente, muito intensa, terminando com a morte do hospedeiro. As inoculações experimentais demonstraram a especificidade da infecção, e diante dos conhecimentos a respeito dos organismos deste gênero, discutimos o problema da criação de espécies.Toddia, a genus created by França 1911 for an organism found in the erythrocytes of an anuran amphibian, has a particular structure and the problem of its viral relationship of protozoa nature is an important point which has recently been discussed. Attempt to resolve this problem must be made using ultrastructure and cytochemical studies. Our results have shown a Feulgen positive reaction and a Methyl-Green positive reaction for this organism, chiefly in the beginning of the infection. At the end of the infection the particles are greater than that in the beginning but the reactions above cited are generaly wakly positive or negative. We have also employed the Acridine orange method in the characterization of DNA and the results are positive too. Further histochemical studies are necessary to determine the true nature of the material observed in this study. We have also studied the development of this organism and its pathogenic effects have been confirmed by experimental inoculation. The alterations in the blood of the host were observed and we noted that the nucleus of the red blood cells is severely disturbed during the development of the infection. The experimental inoculation (in Leptodactylus and Bufo have demonstred specific infectivety which is generaly hard, finishing with the death of the host. The taxonomic aspects related to this genus are discussed and the authors agree to the point of view of Mackerras 1961, and Marquardt 1967, about the identity of Pirhemocyton and Toddia. We need more research to stablish the viral nature of this organism.

  9. Toddia sp., "corpúsculo paranuclear" no sangue de Leptodactylus e Bufo do Brasil: desenvolvimento e citoquímica / Toddia sp. a paranuclear corpuscle in the blood of Leptodactylus and Bufo of Brazil

    Scientific Electronic Library Online (English)

    Neize de Moura, Pereira; Sylvio Celso Gonçalves da, Costa; Maria Auxiliadora de, Sousa.

    Full Text Available O gênero Toddia, criado por França 1911, para um organismo encontrado em eritrõcitos de um anfíbio anuro, tem estrutura particular e o problema de sua natureza (protozoário ou vírus) é discutido. Nosso resultados mostram reações Feulgen e Verde Metila positivas, principalmente no início da infecção. [...] Com o decorrer da infecção as partículas são, geralmente, maiores que aquelas observadas alguns dias após as inoculações, mas as reações citoquímicas citadas anteriormente são, em geral, negativas ou fracamente positivas. Os mesmos resultados foram obtidos quando empregamos Laranja de acridina para caracterização do DNA e esta técnica foi negativa para o RNA. Estudando o desenvolvimento deste organismo e seus efeitos infecciosos foram confirmados por inoculações experimentais. As alterações no sangue do hospedeiro foram observadas e notamos que o núclo dos eritrócitos é severamente alterado durante o desenvolvimento da infecção, que é geralmente, muito intensa, terminando com a morte do hospedeiro. As inoculações experimentais demonstraram a especificidade da infecção, e diante dos conhecimentos a respeito dos organismos deste gênero, discutimos o problema da criação de espécies. Abstract in english Toddia, a genus created by França 1911 for an organism found in the erythrocytes of an anuran amphibian, has a particular structure and the problem of its viral relationship of protozoa nature is an important point which has recently been discussed. Attempt to resolve this problem must be made using [...] ultrastructure and cytochemical studies. Our results have shown a Feulgen positive reaction and a Methyl-Green positive reaction for this organism, chiefly in the beginning of the infection. At the end of the infection the particles are greater than that in the beginning but the reactions above cited are generaly wakly positive or negative. We have also employed the Acridine orange method in the characterization of DNA and the results are positive too. Further histochemical studies are necessary to determine the true nature of the material observed in this study. We have also studied the development of this organism and its pathogenic effects have been confirmed by experimental inoculation. The alterations in the blood of the host were observed and we noted that the nucleus of the red blood cells is severely disturbed during the development of the infection. The experimental inoculation (in Leptodactylus and Bufo) have demonstred specific infectivety which is generaly hard, finishing with the death of the host. The taxonomic aspects related to this genus are discussed and the authors agree to the point of view of Mackerras 1961, and Marquardt 1967, about the identity of Pirhemocyton and Toddia. We need more research to stablish the viral nature of this organism.

  10. Aldosterone increases the apical Na+ permeability of toad bladder by two different mechanisms

    International Nuclear Information System (INIS)

    The aldosterone-induced augmentation of Na+ transport in toad bladder was analyzed by comparing the hormonal actions on the transepithelial short-circuit current and on the amiloride-sensitive 22Na+ uptake in isolated membrane vesicles. Incubating bladders with 0.5 ?M aldosterone for 3 hr evoked more than a 2-fold increase of the short-circuit current but had no effect on the amiloride-sensitive Na+ transport in apical vesicles derived from the treated tissue. A longer incubation produced an additional augmentation of the short-circuit current, which was accompanied by about a 3-fold increase of the channel activity in isolated membranes. The stimulatory effect of aldosterone sustained in vesicles was inhibited by the antagonist spironolactone and the protein synthesis inhibitor cycloheximide. It is suggested that aldosterone elevates the apical Na+ permeability of target epithelia by two different mechanisms: a relatively fast effect which is insensitive to triiodothyronine or butyrate and is not sustained by the isolated membrane, and a slower or later response blocked by these reagents, which is preserved by the isolated membrane. The data also indicate that these processes are mediated by different nuclear receptors

  11. Positive Darwinian selection results in resistance to cardioactive toxins in true toads (Anura: Bufonidae).

    Science.gov (United States)

    Moore, David J; Halliday, Damien C T; Rowell, David M; Robinson, Anthony J; Keogh, J Scott

    2009-08-23

    Members of the Family Bufonidae, true toads, are famous for their endogenously synthesized cardioactive steroids that serve as defensive toxins. Evolution of resistance to these toxins is not understood. We sequenced a key region of the toxin's binding site in the Na(+)/K(+) ATPase for relevant taxa representing Hyloidea (including bufonids), Ranoidea and Archaeobatrachia and tested for positive selection in a phylogenetic context. Bufonidae were distinct from other Hyloidea at 4-6 of 12 sites and, with one exception, had a homologous amino acid sequence. Melanophryniscus stelzneri had a distinct sequence, consistent with other independent evidence for a differentiated toxin. Tests within Bufonidae detected positive selection within the binding region, providing, to our knowledge, the first evidence of this type for positive selection within Amphibia. There was no evidence for positive selection on Bufonidae or M. stelzneri lineages. Sequence change in Leptodactylus ocellatus, a leptodactylid predator of Bufonidae, provides a molecular basis for predator resistance possibly associated with gene duplication. PMID:19465576

  12. Analysis of heart rate control to assess thermal sensitivity responses in Brazilian toads

    Scientific Electronic Library Online (English)

    J.E.S., Natali; B.T., Santos; V.H., Rodrigues; J.G., Chauí-Berlinck.

    2015-01-01

    Full Text Available In anurans, changes in ambient temperature influence body temperature and, therefore, energy consumption. These changes ultimately affect energy supply and, consequently, heart rate (HR). Typically, anurans living in different thermal environments have different thermal sensitivities, and these cann [...] ot be distinguished by changes in HR. We hypothesized that Rhinella jimi (a toad from a xeric environment that lives in a wide range of temperatures) would have a lower thermal sensitivity regarding cardiac control than R. icterica (originally from a tropical forest environment with a more restricted range of ambient temperatures). Thermal sensitivity was assessed by comparing animals housed at 15° and 25°C. Cardiac control was estimated by heart rate variability (HRV) and heart rate complexity (HRC). Differences in HRV between the two temperatures were not significant (P=0.214 for R. icterica and P=0.328 for R. jimi), whereas HRC differences were. All specimens but one R. jimi had a lower HRC at 15°C (all P

  13. Fast and slow voltage modulation of apical Cl- permeability in toad skin at high [K+

    Directory of Open Access Journals (Sweden)

    Procopio J.

    1997-01-01

    Full Text Available The influence of voltage on the conductance of toad skin was studied to identify the time course of the activation/deactivation dynamics of voltage-dependent Cl- channels located in the apical membrane of mitochondrion-rich cells in this tissue. Positive apical voltage induced an important conductance inhibition which took a few seconds to fully develop and was instantaneously released by pulse inversion to negative voltage, indicating a short-duration memory of the inhibiting factors. Sinusoidal stimulation at 23.4 mM [Cl-] showed hysteresis in the current versus voltage curves, even at very low frequency, suggesting that the rate of voltage application was also relevant for the inhibition/releasing effect to develop. We conclude that the voltage modulation of apical Cl- permeability is essentially a fast process and the apparent slow components of activation/deactivation obtained in the whole skin are a consequence of a gradual voltage build-up across the apical membrane due to voltage sharing between apical and basolateral membranes

  14. Fast and slow voltage modulation of apical Cl- permeability in toad skin at high [K+

    Scientific Electronic Library Online (English)

    J., Procopio.

    1997-08-01

    Full Text Available The influence of voltage on the conductance of toad skin was studied to identify the time course of the activation/deactivation dynamics of voltage-dependent Cl- channels located in the apical membrane of mitochondrion-rich cells in this tissue. Positive apical voltage induced an important conductan [...] ce inhibition which took a few seconds to fully develop and was instantaneously released by pulse inversion to negative voltage, indicating a short-duration memory of the inhibiting factors. Sinusoidal stimulation at 23.4 mM [Cl-] showed hysteresis in the current versus voltage curves, even at very low frequency, suggesting that the rate of voltage application was also relevant for the inhibition/releasing effect to develop. We conclude that the voltage modulation of apical Cl- permeability is essentially a fast process and the apparent slow components of activation/deactivation obtained in the whole skin are a consequence of a gradual voltage build-up across the apical membrane due to voltage sharing between apical and basolateral membranes

  15. Phylogeography, geographic structure, genetic variation, and potential species boundaries in Philippine slender toads.

    Science.gov (United States)

    Sanguila, Marites Bonachita; Siler, Cameron D; Diesmos, Arvin C; Nuñeza, Olga; Brown, Rafe M

    2011-11-01

    We investigated phylogeography of Philippine slender toads (genus Ansonia) and used a temporal framework for diversification, statistical tests of alternate topologies, and Bayesian approaches to test previous hypotheses concerning dispersal to, and colonization routes within, the southern Philippine island of Mindanao. Two species of Ansonia previously have been documented, with ranges separated by an east-west split corresponding to the approximate boundaries of Mindanao's paleoisland precursors. We present new mtDNA sequence data (1946 bp from genes encoding ND1, 16S rRNA and tRNALeu) for 105 Ansonia specimens sampled from 20 localities on Mindanao Island. Our data suggest that Philippine Ansonia is composed of at least eight, well-supported population lineages, structured into a minimum of four highly divergent mtDNA clades. One clade corresponds to Ansonia mcgregori, a range-restricted species apparently limited to the distal portion of the Zamboanga Peninsula of western Mindanao. Two morphologically indistinguishable, but genetically divergent, lineages possibly are undescribed cryptic species from western Mindanao. We recognize the five remaining lineages as Ansonia muelleri pending data from morphology or bioacoustics that might diagnose separate species among these lineages. Regardless of their species status, the five allopatric lineages of A. muelleri should be viewed as important genetic units for future genetic conservation planning. PMID:21757017

  16. New species of beaked toad, Rhinella (Anura: Bufonidae), from the State of Bahia, Brazil

    Scientific Electronic Library Online (English)

    Ulisses, Caramaschi.

    2012-08-01

    Full Text Available A new species of beaked toad, Rhinella, is described from Itacaré (14°17'S, 38°60'W; 13 m altitude), State of Bahia, Northeastern Brazil. Rhinella skuki sp. nov. is related to R. boulengeri and distinguished by the size small (SVL 26.2 mm in male); head longer than wide; snout, viewed from above, lo [...] ng, narrow, spatulate, with lateral borders parallel and rounded tip; in profile, long, strongly acute; parotoid glands large, rounded; tympanum concealed; dorsum rugose, with rounded tubercles uniformly distributed; vocal sac and vocal slits absent; fingers slender, not webbed nor ridged; first finger hypertrophied, with a rounded nuptial pad on the inner surface; toes slender, slightly fringed; webbing absent; ground color of dorsal surfaces dark brownish gray with an interorbital bar and dorsolateral blotches clear brownish gray, leaving an apparent pattern of arrows on dorsum; venter and ventral surfaces of arms and thighs cream with diffuse gray stains and dots; gular region and chest dark brownish gray.

  17. New species of beaked toad, Rhinella (Anura: Bufonidae, from the State of Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Ulisses Caramaschi

    2012-08-01

    Full Text Available A new species of beaked toad, Rhinella, is described from Itacaré (14°17'S, 38°60'W; 13 m altitude, State of Bahia, Northeastern Brazil. Rhinella skuki sp. nov. is related to R. boulengeri and distinguished by the size small (SVL 26.2 mm in male; head longer than wide; snout, viewed from above, long, narrow, spatulate, with lateral borders parallel and rounded tip; in profile, long, strongly acute; parotoid glands large, rounded; tympanum concealed; dorsum rugose, with rounded tubercles uniformly distributed; vocal sac and vocal slits absent; fingers slender, not webbed nor ridged; first finger hypertrophied, with a rounded nuptial pad on the inner surface; toes slender, slightly fringed; webbing absent; ground color of dorsal surfaces dark brownish gray with an interorbital bar and dorsolateral blotches clear brownish gray, leaving an apparent pattern of arrows on dorsum; venter and ventral surfaces of arms and thighs cream with diffuse gray stains and dots; gular region and chest dark brownish gray.

  18. Transfer of anti-alcoholic effect of Nux Vomica 200 cH through water from one group of toads to another under alcohol anesthesia

    Directory of Open Access Journals (Sweden)

    Rathin Chakravarty

    2012-12-01

    Full Text Available Background: A common practice is to give homeopathic medication to nursing mothers to treat their children, assuming that the drug will be conveyed by the milk. In the case of conventional treatment, the drug molecules are indeed passed on from the mother to her breastfed infant. However, high dilutions (HD above 12 cH, i.e., over Avogadro’s number, are traditionally held to lack any molecule from the starting material. If that is the case, then, does medication taken by the mother actually reach the child? To answer to that question, we developed plant models and demonstrated the transfer of HD effects between 2 groups of plants. Aims: To demonstrate the transfer of HD effects in an animal model in a much shorter time. Methods: Two batches of toads were respectively placed in two beakers, one containing Nux vomica 200 cH diluted with water 1:500 (direct treatment, and the other the same amount of distilled water were connected by cotton thread soaked in water and encased in a polyethylene tube (connected group; a third batch of toads (control were placed in a beaker with 90% ethanol diluted with distilled water 1:500; all the animals were left 30 minutes, and then transferred to 3 independent beakers containing 209 mM ethanol. Every 10 minutes, the motionless toads were removed from the beakers, and placed on supine position, failure to recover the upright position after 60 sec was considered as loss of the righting reflex (RR. The experiment was replicated using large adult toads. Results: The percentage of toads losing the RR increased with the time of exposure to 209 mM ethanol in the 3 groups of toads. Significant difference in the percentage distribution was found between the control and the direct treatment and connected groups on ?2 test (p < 0.001, p < 0.01, respectively, whereby the latter required much longer time to lose the RR, and did not differed between them. In the experiment with large adult toads, the control group lost RR in 78 min, whereas the 2 treated groups did not lose RR even after 240 min. Conclusion: Nux-v 200 cH countered the hypnotic effect of alcohol in young toads, and this effect was transferred through capillary water in the cotton thread, supporting the transfer of the effect of homeopathic medication from mother to child.

  19. Relación entre la temperatura corporal de adultos de Bufo arenarum (Anura: Bufonidae y variables ambientales en un humedal de San Juan, Argentina

    Directory of Open Access Journals (Sweden)

    Eduardo A. Sanabria

    2003-01-01

    Full Text Available El objetivo del trabajo fue relacionar la temperatura corporal (TC de Bufo arenarum con variables ambientales en un humedal de San Juan. La TC usada fue un promedio de todos los datos térmicos por muestra (día registrados con un termómetro de lectura rápida desde diciembre de 2001 hasta noviembre de 2002 mediante 25 muestreos. La TC se relacionó con las variables meteorológicas: t° media, heliofanía y viento a 0,50 m del suelo tomadas el mismo día. Se realizaron análisis de regresión múltiple con todos los registros. La TC mostró una regresión significativa con las variables en conjunto lo que indica la influencia de éstas sobre la temperatura corporal de la especie.

  20. Breeding pond selection and movement patterns by eastern spadefoot toads (Scaphiopus holbrookii) in relation to weather and edaphic conditions.

    Energy Technology Data Exchange (ETDEWEB)

    Greenberg, Cathyrn, H.; Tanner, George, W.

    2004-08-31

    Cathryn H. Greenberg and George W. Tanner. 2004. Breeding pond selection and movement patterns by eastern spadefoot toads (Scaphiopus holbrookii) in relation to weather and edaphic conditions. J. Herp. 38(4):569-577. Abstract: Eastern Spadefoot Toads (Scaphiopus holbrookii) require fish-free, isolated, ephemeral ponds for breeding but otherwise inhabit the surrounding uplands, commonly xeric longleaf pine (Pinus palustris) ?wiregrass (Aristida beyrichiana). Hence both pond and upland conditions can potentially affect their breeding biology, and population persistence. Hardwood invasion due to fire suppression in sandhills could alter upland and pond suitability by higher hardwood density and increased transpiration. In this paper we explore breeding and neonatal emigration movements in relation to weather, hydrological conditions of ponds, and surrounding upland matrices. We use 9 years of data from continuous monitoring with drift fences and pitfall traps at 8 ephemeral ponds in 2 upland matrices: regularly-burned, savanna-like sandhills (n = 4), and hardwood-invaded sandhills (n = 4). Neither adult nor neonate captures differed between ponds within the 2 upland matrices, suggesting that they are tolerant of upland heterogeneity created by fire frequency. Explosive breeding occurred during 9 periods and in all seasons; adults were captured rarely otherwise. At a landscape-level rainfall, maximum change in barometric pressure, and an interaction between those 2 variables were significant predictors of explosive breeding. At a pond-level, rainfall, change in pond depth during the month prior to breeding, and days since a pond was last dry were significant predictors of adult captures. Transformation date, rather than weather, was associated with neonatal emigrations, which usually were complete within a week. Movement by first-captured adults and neonates was directional, but adult emigrations were apparently not always toward their origin. Our results suggest that Spadefoot Toads are highly adapted to breeding conditions and upland habitat heterogeneity created by weather patterns and fire frequency in Florida sandhills.

  1. Population traits of the burrowing toad Rhinella fernandezae (Gallardo, 1957 (Anura, Bufonidae Características populacionais do sapo Rhinella fernandezae (Anura, Bufonidae

    Directory of Open Access Journals (Sweden)

    LC. Sanchez

    2008-02-01

    Full Text Available Size distribution, sex ratio and use of burrows of the burrowing toad Rhinella fernandezae were studied in Buenos Aires province, Argentina. Two sites separated by approximately 300 m were studied: one was a road next to a swamp, and the other a garden of a country house located further from the swamp. We identified toad burrows, and individuals were sexed, measured and given an individual mark. Burrows were examined in subsequent months after the first sampling to assess the presence of toads. We found significant differences in the size distribution between areas, being the proportion of juveniles greater at the site next to the swamp where the reproduction of the species was observed. This result may suggest that the site located near to the swamp functions as a source habitat of individuals that migrate to the other site, where recruitment would be very scarce. Sex proportion of adults did not differ from 1:1 in neither the total population nor in each site, suggesting that there was not differential mortality by sex. Some toads changed burrows throughout the study period, but there were not differences in the frequency of change between adults and juveniles.Distribuição de tamanho, razão sexual operacional, e uso de covas do sapo Rhinella fernandezae foram estudados na província de Buenos Aires, Argentina, em dois sítios afastados 300 m. Um deles é uma trilha próxima a um pântano, o outro, um jardim de uma casa rural, mais afastado do pântano. Identificamos as covas dos sapos, e os indivíduos dentro delas foram sexados, medidos e marcados individualmente. As covas foram monitoradas mensalmente, depois da primeira amostragem para avaliar a presença dos sapos. Achamos diferenças na distribuição de tamanhos entres os sítios, sendo a proporção de juvenis maior naquele próximo ao pântano, onde a reprodução da espécie foi observada. O resultado sugere que o sítio próximo ao pântano funciona como um habitat fonte de indivíduos que migram para aquele mais afastado, onde o recrutamento seria escasso. A taxa entre os sexos dos adultos não foi diferente de 1:1 em nenhum dos sítios amostrados, nem na população total, sugerindo que não existe mortalidade diferencial entre machos e fêmeas. Alguns sapos mudaram de cova durante o período do estudo, mas não houve diferenças na freqüência de mudança entre juvenis e adultos.

  2. Population traits of the burrowing toad Rhinella fernandezae (Gallardo, 1957) (Anura, Bufonidae) / Características populacionais do sapo Rhinella fernandezae (Anura, Bufonidae)

    Scientific Electronic Library Online (English)

    LC., Sanchez; M., Busch.

    2008-02-01

    Full Text Available Distribuição de tamanho, razão sexual operacional, e uso de covas do sapo Rhinella fernandezae foram estudados na província de Buenos Aires, Argentina, em dois sítios afastados 300 m. Um deles é uma trilha próxima a um pântano, o outro, um jardim de uma casa rural, mais afastado do pântano. Identifi [...] camos as covas dos sapos, e os indivíduos dentro delas foram sexados, medidos e marcados individualmente. As covas foram monitoradas mensalmente, depois da primeira amostragem para avaliar a presença dos sapos. Achamos diferenças na distribuição de tamanhos entres os sítios, sendo a proporção de juvenis maior naquele próximo ao pântano, onde a reprodução da espécie foi observada. O resultado sugere que o sítio próximo ao pântano funciona como um habitat fonte de indivíduos que migram para aquele mais afastado, onde o recrutamento seria escasso. A taxa entre os sexos dos adultos não foi diferente de 1:1 em nenhum dos sítios amostrados, nem na população total, sugerindo que não existe mortalidade diferencial entre machos e fêmeas. Alguns sapos mudaram de cova durante o período do estudo, mas não houve diferenças na freqüência de mudança entre juvenis e adultos. Abstract in english Size distribution, sex ratio and use of burrows of the burrowing toad Rhinella fernandezae were studied in Buenos Aires province, Argentina. Two sites separated by approximately 300 m were studied: one was a road next to a swamp, and the other a garden of a country house located further from the swa [...] mp. We identified toad burrows, and individuals were sexed, measured and given an individual mark. Burrows were examined in subsequent months after the first sampling to assess the presence of toads. We found significant differences in the size distribution between areas, being the proportion of juveniles greater at the site next to the swamp where the reproduction of the species was observed. This result may suggest that the site located near to the swamp functions as a source habitat of individuals that migrate to the other site, where recruitment would be very scarce. Sex proportion of adults did not differ from 1:1 in neither the total population nor in each site, suggesting that there was not differential mortality by sex. Some toads changed burrows throughout the study period, but there were not differences in the frequency of change between adults and juveniles.

  3. A Suspected Parasite Spill-Back of Two Novel Myxidium spp. (Myxosporea) Causing Disease in Australian Endemic Frogs Found in the Invasive Cane Toad.

    Czech Academy of Sciences Publication Activity Database

    Hartigan, A.; Fiala, Ivan; Dyková, Iva; Jirk?, Miloslav; Okimoto, B.; Rose, K.; Phalen, D. N.; Šlapeta, J.

    2011-01-01

    Ro?. 6, ?. 4 (2011), e18871. ISSN 1932-6203 R&D Projects: GA AV ?R KJB600960701 Grant ostatní: GA ?R(CZ) GP204/09/P519 Institutional research plan: CEZ:AV0Z60220518 Keywords : EW-SOUTH-WALES * BUFO-MARINUS * BIOLOGICAL INVASIONS * INFECTIOUS-DISEASES * NORTH-AMERICA * TREE FROG * MYXOZOA * SEQUENCES * PHYLOGENY * ECOLOGY Subject RIV: EG - Zoology Impact factor: 4.092, year: 2011

  4. Spatial and temporal ecology of eastern spadefoot toads on a Florida landscape.

    Energy Technology Data Exchange (ETDEWEB)

    Greenberg, Cathyrn, H.; Tanner, George, W.

    2005-03-01

    Effective amphibian conservation must consider population and landscape processes, but information at multiple scales is rare. We explore spatial and temporal patterns of breeding and recruitment by Eastern Spadefoot Toads (Scaphiopus holbrookii), using 9 years of data from continuous monitoring with drift fences and pitfall traps at 8 ephemeral ponds in longleaf pine-wiregrass sandhills. Breeding events (>25 adults at a pond within a month) occurred 23 times on nine occasions at seven of the eight study ponds, but substantial recruitment(>100 metamorphs) followed only five events. Recruitment ranged from 0-4,648 among ponds. Only four ponds functioned as population ''sources'', but only during some years. The other ponds, and even ''source'' ponds during some years, functioned either as ''sinks'', where breeding occurred with no resulting recruitment, or were not used at all for breeding. Most recruitment occurred during four years. Recruitment was correlated with adult breeding effort, but only during some years. Recaptures were rare, and inter-pond exchange of adults was minimal and short-distance (< 130 m; 1 was 416 m). Most (83.5%) individuals captured were metamorphs, and 15.9% were > 51 mm (est. > 4 years). We conservatively estimated a 7-year lifespan. Adult ''population'' trends clearly reflected breeding effort rather than numbers per se; capture rates fluctuated dramatically among years, but showed no overall trends during the 9-year study. Our paper provides empiracle information that can be used to generate realistic metapopulation models for S. holbrookii as a tool in conservation planning.

  5. AVALIATION OF VENTILATORY PATTERN IN THE TOAD RHINELLA SCHNEIDERI (ANURA: BUFONIDAE

    Directory of Open Access Journals (Sweden)

    FERNANDES, Marcelo dos Santos

    2010-11-01

    Full Text Available Amphibians ventilated their lungs by buccal pumping mechanism, which was first described in 1969 as a model for studying anurans respiration. Since amphibians do not have alveoli in their lungs, wecalculated to the toad Rhinella schneideri the equivalent lung ventilation from the equation VEFF = (VLCO2·RT/PLCO2. We analyzed buccal and pulmonary pressures, respiratory volumes, lung and buccalventilation, and ventilation frequency. [VE (12,1 ± 0,6ml BTPS.min-1.kg-1 ; VEB (164,3 ± 2,2ml BTPS.min-1.kg- 1 ; fR (5,8 ± 0,4min-1; buccal frequencies (68,5 ± 1,6min-1; Tidal volume(VT = 2.4 ml BTPS·kg-1]. The low oxygen extraction (17,3 ± 2,8% was used to explain the high frequency of pulmonary and buccal ventilation.Os anfíbios ventilam seus pulmões por meio de bombeamento bucal, mecanismo que foi primeiramente descrito 1969 como um modelo para a respiração de anuros. Como os anfíbios não possuem alvéolos em seus pulmões, foi calculado para o sapo Rhinella schneideri a ventilação equivalente do pulmão por meio da equação VEFF = (VLCO2·RT/PLCO2. Analisamos as pressões bucais e pulmonares, os volumes respiratórios, ventilação pulmonar e bucal, e frequências de ventilação. [VE (12,1 ± 0,6 ml BTPS.min-1.kg-1; VEB (164,3 ± 2,2 ml BTPS.min-1.kg-1; fR (5,8 ± 0,4 min -1; Freqüência bucal (68,5 ± 1,6 min-1; volume corrente(VT = 2,4 BTPS ml • kg-1]. A baixa extração de oxigênio (17,3% ± 2,8 foi utilizada para explicar a alta freqüência da ventilação pulmonar e bucal.

  6. Acute toxicity of arsenic and oxidative stress responses in the embryonic development of the common South American toad Rhinella arenarum.

    Science.gov (United States)

    Mardirosian, Mariana Noelia; Lascano, Cecilia Inés; Ferrari, Ana; Bongiovanni, Guillermina Azucena; Venturino, Andrés

    2015-05-01

    Arsenic (As), a natural element of ecological relevance, is found in natural water sources throughout Argentina in concentrations between 0.01?mg/L and 15?mg/L. The autochthonous toad Rhinella arenarum was selected to study the acute toxicity of As and the biochemical responses elicited by the exposure to As in water during its embryonic development. The median lethal concentration (LC50) value averaged 24.3?mg/L As and remained constant along the embryonic development. However, As toxicity drastically decreased when embryos were exposed from heartbeat-stage on day 4 of development, suggesting the onset of detoxification mechanisms. Given the environmental concentrations of As in Argentina, there is a probability of exceeding lethal levels at 1% of sites. Arsenic at sublethal concentrations caused a significant decrease in the total antioxidant potential but generated an increase in endogenous glutathione (GSH) content and glutathione S-transferase (GST) activity. This protective response might prevent a deeper decline in the antioxidant system and further oxidative damage. Alternatively, it might be linked to As conjugation with GSH for its excretion. The authors conclude that toad embryos are more sensitive to As during early developmental stages and that relatively high concentrations of this toxic element are required to elicit mortality, but oxidative stress may be an adverse effect at sublethal concentrations. Environ Toxicol Chem 2015;34:1009-1014. © 2014 SETAC. PMID:25523521

  7. The effect of supplementation with vitamin A on serum and liver concentrations in Puerto Rican crested toads (Peltophryne lemur) and its lack of impact on brown skin disease.

    Science.gov (United States)

    Dutton, Christopher; Lentini, Andrew; Berkvens, Charlene; Crawshaw, Graham

    2014-01-01

    "Brown skin disease" (BSD) is a clinical syndrome of dysecdysis, chronic weight loss and death, previously reported in Puerto Rican crested toads (Peltophryne lemur). Although vitamin A deficiency has been suggested, its cause remains unknown and multiple treatments have failed to prevent or reverse the condition. This study compared the efficacy of vitamin A supplementation, administered in different forms and by different routes, in 48 captive born Puerto Rican crested toads fed from metamorphosis on gut-loaded, dusted, commercially raised crickets. Forty-five toads started to show clinical signs of BSD at 9 months of age; all toads were treated orally with an oil-based vitamin A formulation twice weekly for 2 months but continued to deteriorate. Two treatment groups were then compared: Animals in one group (n=19) received 2 IU injectable vitamin A (Aquasol-A) per gram bodyweight subcutaneously twice weekly for 3 months with no change in diet. Toads in the other group (n=22) received a single oral dose of vitamins A, D3 , and E, and were fed on earthworms and crickets gut-loaded with produce and a finely-ground alfalfa-based pellet, dusted with the same vitamin/mineral supplement. All affected animals developed severe BSD equally and died during, or were euthanized at the end of, the treatment regimen, with no clinical improvement. Animals supplemented with Aquasol-A had significantly higher liver vitamin A concentrations compared with the other treatment group, whereas serum retinol concentrations showed no significant difference. Vitamin A supplementation does not appear a successful treatment once BSD symptoms have developed. PMID:25183002

  8. Delimiting genetic units in Neotropical toads under incomplete lineage sorting and hybridization

    Directory of Open Access Journals (Sweden)

    Thomé Maria Tereza C

    2012-12-01

    Full Text Available Abstract Background Delimiting genetic units is useful to enhance taxonomic discovery and is often the first step toward understanding evolutionary mechanisms generating diversification. The six species within the Rhinella crucifer group of toads were defined under morphological criteria alone. Previous data suggest limited correspondence of these species to mitochondrial lineages, and morphological intergradation at transitions between forms suggests hybridization. Here we extensively sampled populations throughout the geographic distribution of the group and analyzed mitochondrial and nuclear sequence data to delimit genetic units using tree–based and allele frequency–based approaches. Results These approaches yielded complementary results, with allele frequency-based methods performing unexpectedly well given the limited number of loci examined. Both mitochondrial and nuclear markers supported a genetic structure of five units within the group, with three of the inferred units distributed within its main range, while two other units occur in separate isolates. The inferred units are mostly discordant with currently described forms: unequivocal association exists for only two of the six species in the group. Genetic evidence for hybridization exists for two pairs of units, with clear cyto–nuclear allele mixing observed in one case. Conclusions Our results confirmed that current taxonomy does not represent evolutionary units in the Rhinella crucifer group. Correspondence between genetically distinguishable units and the currently recognized species is only possible for Rhinella henseli and R. inopina. The recognition of other species relies on the reassessment of the geographic range of R. crucifer, the examination of the type series of R. ornata for hybrids, and on the use of additional markers to verify the genetic distinctiveness of R. abei. We state that R. pombali should not remain a valid species since its description appears to be based on hybrids, and that the name R. pombali should be considered a synonym of both R. crucifer and R. ornata. The fifth inferred but undescribed genetic unit may represent a new species. Our results underscore the potential of the R. crucifer species group to contribute to a better understanding of diversification processes and hybridization patterns in the Neotropics, and provide the basis for future evolutionary and taxonomic studies.

  9. Arenobufagin, a bufadienolide compound from toad venom, inhibits VEGF-mediated angiogenesis through suppression of VEGFR-2 signaling pathway.

    Science.gov (United States)

    Li, Manmei; Wu, Shuai; Liu, Zhong; Zhang, Wei; Xu, Jing; Wang, Ying; Liu, Junshan; Zhang, Dongmei; Tian, Haiyan; Li, Yaolan; Ye, Wencai

    2012-05-01

    Angiogenesis is crucial for carcinogenesis and other angiogenic processes. Arenobufagin, one of the major components of toad venom, is a traditional Chinese medicine used for cancer therapy. It inhibits cell growth in several cancer cell lines. However, little is known about arenobufagin's anti-angiogenic activity. In this study, we showed that arenobufagin inhibited vascular endothelial growth factor (VEGF)-induced viability, migration, invasion and tube formation in human umbilical vein endothelial cells (HUVECs) in vitro. Arenobufagin also suppressed sprouting formation from VEGF-treated aortic rings in an ex vivo model. Furthermore, we found that arenobufagin blocked angiogenesis in a matrigel plugs assay. Computer simulations suggested that arenobufagin interacted with the ATP-binding sites of VEGFR-2 by docking. In addition, arenobufagin inhibited VEGF-induced VEGFR-2 auto-phosphorylation and suppressed the activity of VEGFR-2-mediated signaling cascades. Taken together, our findings demonstrate that arenobufagin is a specific inhibitor of VEGF-mediated angiogenesis. PMID:22305746

  10. Quantitative recommendations for amphibian terrestrial habitat conservation derived from habitat selection behavior

    OpenAIRE

    Indermaur, L.; Schmidt, B. R.

    2011-01-01

    Conservation scientists have noted that conservation managers rarely use scientific information when making decisions. One of the reasons why managers rarely use scientific information may be that conservation scientists rarely provide their knowledge in a way that can directly be used by conservation practitioners. Here we show how quantitative recommendations for conservation can be derived. Previous research on terrestrial habitat selection behavior of toads (Bufo bufo and Bufo viridis) sh...

  11. Locomotion and survival of two sympatric larval anurans, Bufo gargarizans (Anura: Bufonidae) and Rana zhenhaiensis (Anura: Ranidae), after partial tail loss

    Scientific Electronic Library Online (English)

    Guo-Hua, Ding; Zhi-Hua, Lin; Li-Hua, Zhao.

    2014-08-01

    Full Text Available Tadpoles of two sympatric anurans, Bufo gargarizans Cantor, 1842 and Rana zhenhaiensis Ye, Fei & Matsui, 1995, were used as model organisms to examine the effects of different levels of tail loss on swimming performance and survival. On average, B. gargarizans tadpoles were shorter and had smaller t [...] ails and body mass than R. zhenhaiensis. After 75% tail loss, the survival rate of experimental and control B. gargarizans tadpoles, and of experimental tadpoles of the two species, differed significantly; the number of tadpoles surviving a complete impairment of their swimming ability did not differ between B. gargarizans and R. zhenhaiensis. After 50% tail loss, the swimming performance (swimming speed, maximum distance and number of stops) of the two species was significantly affected. However, the adverse influence of tail loss on the swimming speed of B. gargarizans tadpoles was greater compared to R. zhenhaiensis tadpoles. Our data indicates that a 50% tail loss results in swimming costs for B. gargarizans and R. zhenhaiensis tadpoles, and that 75% tail loss decreases the survival rate of B. gargarizans tadpoles. Therefore, we conclude that tadpoles of different species and with the same degree of tail loss use distinctive strategies to improve individual fitness in the face of predator pressure.

  12. The smooth muscle pharmacology of maximakinin, a receptor-selective, bradykinin-related nonadecapeptide from the venom of the Chinese toad, Bombina maxima.

    Science.gov (United States)

    O'Rourke, Martin; Chen, Tianbao; Hirst, David G; Rao, Pingfan; Shaw, Chris

    2004-09-15

    Structural homologues of vertebrate regulatory peptides found in defensive skin secretions of anuran amphibians often display enhanced bioactivity and receptor binding when compared with endogenous mammalian peptide ligands. Maximakinin, a novel N-terminally extended bradykinin (DLPKINRKGPRPPGFSPFR) from the skin venom of a Chinese toad (Bombina maxima), displays such activity enhancement when compared with bradykinin but is additionally highly selective for mammalian arterial smooth muscle bradykinin receptors displaying a 50-fold increase in molar potency in this smooth muscle type. In contrast, a 100-fold decrease in molar potency was observed at bradykinin receptors in intestinal and uterine smooth muscle preparations. Maximakinin has thus evolved as a "smart" defensive weapon in the toad with receptor/tissue selective targeting. Natural selection of amphibian skin venom peptides for antipredator defence, through inter-species delivery by an exogenous secretory mode, produces subtle structural stabilisation modifications that can potentially provide new insights for the design of selectively targeted peptide therapeutics. PMID:15256275

  13. Regulation of the sodium permeability of the luminal border of toad bladder by intracellular sodium and calcium: role of sodium-calcium exchange in the basolateral membrane

    OpenAIRE

    1981-01-01

    Sodium movement across the luminal membrane of the toad bladder is the rate-limiting step for active transepithelial transport. Recent studies suggest that changes in intracellular sodium regulate the Na permeability of the luminal border, either directly or indirectly via increases in cell calcium induced by the high intracellular sodium. To test these proposals, we measured Na movement across the luminal membrane (th Na influx) and found that it is reduced when intracellular Na is increased...

  14. Hybridization and massive mtDNA unidirectional introgression between the closely related Neotropical toads Rhinella marina and R. schneideri inferred from mtDNA and nuclear markers

    OpenAIRE

    Schneider Horacio; Sampaio Iracilda; Bernardi José AR; Ferrand Nuno; Sodré Davidson; Sequeira Fernando; Vallinoto Marcelo

    2011-01-01

    Abstract Background The classical perspective that interspecific hybridization in animals is rare has been changing due to a growing list of empirical examples showing the occurrence of gene flow between closely related species. Using sequence data from cyt b mitochondrial gene and three intron nuclear genes (RPL9, c-myc, and RPL3) we investigated patterns of nucleotide polymorphism and divergence between two closely related toad species R. marina and R. schneideri. By comparing levels of dif...

  15. Toad radiation reveals into-India dispersal as a source of endemism in the Western Ghats-Sri Lanka biodiversity hotspot

    Directory of Open Access Journals (Sweden)

    Bossuyt Franky

    2009-06-01

    Full Text Available Abstract Background High taxonomic level endemism in the Western Ghats-Sri Lanka biodiversity hotspot has been typically attributed to the subcontinent's geological history of long-term isolation. Subsequent out of – and into India dispersal of species after accretion to the Eurasian mainland is therefore often seen as a biogeographic factor that 'diluted' the composition of previously isolated Indian biota. However, few molecular studies have focussed on into-India dispersal as a possible source of endemism on the subcontinent. Using c. 6000 base pairs of mitochondrial and nuclear DNA, we investigated the evolutionary history and biogeography of true toads (Bufonidae, a group that colonized the Indian Subcontinent after the Indo-Asia collision. Results Contrary to previous studies, Old World toads were recovered as a nested clade within New World Bufonidae, indicating a single colonization event. Species currently classified as Ansonia and Pedostibes were both recovered as being non-monophyletic, providing evidence for the independent origin of torrential and arboreal ecomorphs on the Indian subcontinent and in South-East Asia. Our analyses also revealed a previously unrecognized adaptive radiation of toads containing a variety of larval and adult ecomorphs. Molecular dating estimates and biogeographic analyses indicate that the early diversification of this clade happened in the Western Ghats and Sri Lanka during the Late Oligocene to Early Miocene. Conclusion Paleoclimate reconstructions have shown that the Early Neogene of India was marked by major environmental changes, with the transition from a zonal- to the current monsoon-dominated climate. After arrival in the Western Ghats-Sri Lanka hotspot, toads diversified in situ, with only one lineage able to successfully disperse out of these mountains. Consequently, higher taxonomic level endemism on the Indian Subcontinent is not only the result of Cretaceous isolation, but also of invasion, isolation and radiation of new elements after accretion to the Eurasian mainland.

  16. Anti-inflammatory Drug (Indomethacin) and its Effect on Liver Tumor Induced by DMBA

    OpenAIRE

    N. E. Abdelmeguid; I. A. Sadek; J. M. Sorour; A.A. Attia

    1999-01-01

    Liver tumors were induced in the toads, Bufo regularis, , in 16 out of 50 cases by the administration of 0.2 mg DMBA/toad, 3 times / week for 12 weeks. Light and electron microscopic photographs demonstrate that these hepatocytes of DMBA - treated toads showed criteria of malignancy. In contrast, toads treated with DMBA at the same dose level and 0.005 per cent w/w indomethacin / toad, 3 times / week for 12 weeks showed a lower incidence of liver tumors, 8 out of 50 cases. The biochemical ana...

  17. Responses of toad tadpoles to ammonium nitrate fertilizer and predatory stress: differences between populations on a local scale.

    Science.gov (United States)

    Ortiz-Santaliestra, Manuel E; Fernández-Benéitez, María José; Lizana, Miguel; Marco, Adolfo

    2011-06-01

    Agriculture-related pollution is among the major causes of global amphibian population declines. The multiple stressors to which amphibians are exposed in the field, such as predation pressure, can make agrochemicals far more deadly than when they act in isolation. Even within a small area, diffuse agricultural pollution does not affect all aquatic environments equally, which could account for local differences in amphibian sensitivity to agrochemicals. We examined the combined effects of ammonium nitrate fertilizer (0 to 45.2?mg N-NH?4(+)/L) and predator stress on larval Western spadefoot toad (Pelobates cultripes), using adult caged male marbled newts (Triturus marmoratus) as predators. We compared the interaction between both stressors in tadpoles from two ponds separated by 3?km. No significant mortality was observed (survival >?80% in all cases). Local differences were detected when analyzing larval growth, with a significant interaction between factors for one of the two populations tested (Fornillos de Fermoselle). Although tadpoles exposed to 45.2?mg N-NH?4(+)/L were 7% smaller than controls, the presence of predators from a foreign community resulted in animals 15% larger than those raised without predators after 15 d of experiment. Interestingly, predators from the same community as the tadpoles did not affect larval growth. The length of the tadpoles from a nearby location (Mámoles) was unaffected after exposure to ammonium nitrate and predatory stress. PMID:21384420

  18. Calcium reduces the sodium permeability of luminal membrane vesicles from toad bladder. Studies using a fast-reaction apparatus

    International Nuclear Information System (INIS)

    Regulation of the sodium permeability of the luminal membrane is the major mechanism by which the net rate of sodium transport across tight epithelia is varied. Previous evidence has suggested that the permeability of the luminal membrane might be regulated by changes in intracellular sodium or calcium activities. To test this directly, we isolated a fraction of the plasma membrane from the toad urinary bladder, which contains a fast, amiloride-sensitive sodium flux with characteristics similar to those of the native luminal membrane. Using a flow-quench apparatus to measure the initial rate of sodium efflux from these vesicles in the millisecond time range, we have demonstrated that the isotope exchange permeability of these vesicles is very sensitive to calcium. Calcium reduces the sodium permeability, and the half-maximal inhibitory concentration is 0.5 microM, well within the range of calcium activity found in cells. Also, the permeability of the luminal membrane vesicles is little affected by the ambient sodium concentration. These results, when taken together with studies on whole tissue, suggest that cell calcium may be an important regulator of transepithelial sodium transport by its effect on luminal sodium permeability. The effect of cell sodium on permeability may be mediated by calcium rather than by sodium itself

  19. Sulfate transport in toad skin : evidence for mitochondria-rich cell pathways in common with halide ions

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Simonsen, K

    1988-01-01

    1. In short-circuited toad skin preparations exposed bilaterally to NaCl-Ringer's containing 1 mM SO2(-4), influx of sulfate was larger than efflux showing that the skin is capable of transporting sulfate actively in an inward direction. 2. This active transport was not abolished by substituting apical Na+ for K+. 3. Following voltage activation of the passive Cl- permeability of the mitochondria-rich (m.r.) cells sulfate flux-ratio increased to a value predicted from the Ussing flux-ratio equation for a monovalent anion. 4. In such skins, which were shown to exhibit vanishingly small leakage conductances, the variation of the rate coefficient for sulfate influx (y) was positively correlated with the rate coefficient for Cl- influx (x), y = 0.035 x - 0.0077 cm/sec (r = 0.9935, n = 15). 5. Addition of the phosphodiesterase inhibitor, 3-isobutyl-1-methyl-xanthine to the serosal bath of short-circuited preparations resulted in a significant stimulation of the passive Cl- and SO2(-4) permeabilities. 6. It is suggested that SO2(-4) and Cl- ions are transported along the same pathway of the m.r. cells. Depending on the transport mode of the apical Cl- transport system, electro-diffusion, active transport (sulfate:bicarbonate exchange) and self-exchange diffusion take place. Irrespective of the mechanism of transport, sulfate is probably transported as a monovalent anion species.

  20. Feeding pattern and use of reproductive habitat of the Striped toad Rhinella crucifer (Anura: Bufonidae from Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigo B. Ferreira

    2009-12-01

    Full Text Available Diet composition, foraging mode, and using of reproductive habitat of Rhinella crucifer was studied in an artificial pond in Espírito Santo, Brazil. The favored substrate was leaf litter, followed by Cyperaceae/Poaceae. Calling sites, preferred for 23.3 % (n = 7 of the observed toads, were within the water, with only the head not submerged. We analyzed a total of 61 specimens, mainly males (98.5% male and 1.5% female. Seven categories of prey were found in the stomach contents: Coleoptera, Hymenoptera (Formicidae, Isoptera, Lepidoptera, Orthoptera, Gastropoda (Mollusca, Opilionida (Arachnida. Our studies indicate that the diet of Rhinella crucifer consists mainly of terrestrial colonial arthropods. Formicidae was the predominant food item in frequency of occurrence, number of prey and weight. Isoptera and Coleoptera were also relevant in terms of weight. Neither large ontogenetic dietary nor seasonal shifts were observed in the population studied. Our results suggest that no intraspecific food resource partitioning occurs in adult or juveniles. Rhinella crucifer adults avoid competition inhabiting different home range habitats and seem to be ant-specialist with a wide foraging mode.

  1. Barriers, rather than refugia, underlie the origin of diversity in toads endemic to the Brazilian Atlantic Forest.

    Science.gov (United States)

    Thomé, Maria Tereza C; Zamudio, Kelly R; Haddad, Célio F B; Alexandrino, João

    2014-12-01

    In this study, we investigated the relative contribution of geographic barriers and Pleistocene refuges in the diversification of the Rhinella crucifer species complex, a group of endemic toads with a widespread distribution in the Brazilian Atlantic Forest (AF). We used intensive sampling and multilocus DNA sequence data to compare nucleotide diversity between refuge and nonrefuge areas, investigate regional demographic patterns, estimate demographic parameters related to genetic breaks and test refuge versus barrier scenarios of diversification using approximate Bayesian computation. We did not find higher levels of genetic diversity in putative refuge areas, either at regional or biome scale. Rather, the demographic history of the species complex supports regional differences with moderate population growth in the north and central regions and stability in southern AF. Genetic breaks were dated to the Plio-Pleistocene; however, our analyses rejected the role of refuges in creating a northern and central divergence, supporting a recent colonization scenario at a smaller scale within the central AF. Overall, our data rule out massive climatically driven fragmentation and large-scale recolonization events for populations across the biome. We confirmed the importance of geographic barriers in creating main divergences and underscored the importance of searching for cryptic discontinuities in the landscape. Comparison of our results with those of other AF taxa indicates organismal specific responses to moderate shifts in habitat and that multiple refuges may constitute a more realistic model for diversification of Atlantic Forest biota. PMID:25363843

  2. Regulation of cyclic GMP metabolism in toad photoreceptors. Definition of the metabolic events subserving photoexcited and attenuated states

    International Nuclear Information System (INIS)

    Photoreceptor metabolism of cGMP and its regulation were characterized in isolated toad retinas by determining the intensity and time dependence of light-induced changes in the following metabolic parameters: cGMP hydrolytic flux determined by the rate of 18O incorporation from 18O-water into retinal guanine nucleotide alpha-phosphoryls; changes in the total concentrations of the guanine nucleotide metabolic intermediates; and changes in the concentration of metabolic GDP calculated from the fraction of the alpha-GDP that undergoes labeling with 18O. With narrow band 500 nm light that preferentially stimulates red rod photoreceptors, a range of intensities covering approximately 5 log units produced increases of over 10-fold in cGMP metabolic flux. However, the characteristics of the cGMP metabolic response over the first 2.5 log units of intensity are readily distinguishable from those at higher intensities which exhibit progressive attenuation by an intensity- and time-dependent process. Over the range of low intensities the metabolic response is characterized by 1) increases in cGMP hydrolytic flux of up to 8-fold as a logarithmic function of intensity of photic stimulation that are sustained for at least 200 s; 2) small increases or no change in the concentration of total cGMP; 3) large increases of up to 10-fold in the concentration of metabolically active GDP as a linear function of intensity with no significant change in the tissue concentrations of total GDP on the tissue concentrations of total GDP or GTP; and 4) amplification of the photosignal by the metabolism of approximately 10,000 molecules of cGMP per photoisomerization with the major site of amplification at the level of the interaction of bleached rhodopsin with G-protein

  3. Expression of cell adhesion molecules in the normal and T3 blocked development of the tadpole's kidney of Bufo arenarum (Amphibian, Anuran, Bufonidae Expressão das moléculas de adesão celular no desenvolvimento normal e com a inibição do hormônio tireoidea do rim nas larvas do Bufo arenarum (Amphibia, Anura, Bufonidae

    Directory of Open Access Journals (Sweden)

    MF. Izaguirre

    2008-08-01

    Full Text Available Cell adhesion molecules act as signal transducers from the extracellular environment to the cytoskeleton and the nucleus and consequently induce changes in the expression pattern of structural proteins. In this study, we showed the effect of thyroid hormone (TH inhibition and arrest of metamorphosis on the expression of E-cadherin, ?-and ?-catenin in the developing kidney of Bufo arenarum. Cell adhesion molecules have selective temporal and spatial expression during development suggesting a specific role in nephrogenesis. In order to study mechanisms controlling the expression of adhesion molecules during renal development, we blocked the B. arenarum metamorphosis with a goitrogenic substance that blocks TH synthesis. E-cadherin expression in the proximal tubules is independent of thyroid control. However, the blockage of TH synthesis causes up-regulation of E-cadherin in the collecting ducts, the distal tubules and the glomeruli. The expression of ?-and ?-catenin in the collecting ducts, the distal tubules, the glomeruli and the mesonephric mesenchyme is independent of TH. TH blockage causes up-regulation of ?-and ?-catenin in the proximal tubules. In contrast to E-cadherin, the expression of the desmosomal cadherin desmoglein 1 (Dsg-1 is absent in the control of the larvae kidney during metamorphosis and is expressed in some interstitial cells in the KClO4 treated larvae. According to this work, the Dsg-1 expression is down-regulated by TH. We demonstrated that the expression of E-cadherin, Dsg-1, ?-catenin and ?-catenin are differentially affected by TH levels, suggesting a hormone-dependent role of these proteins in the B. arenarum renal metamorphosis.Moléculas de adesão celular atuam como tradutores do ambiente extracelular para o citoesqueleto e o núcleo e, conseqüentemente, induzindo mudanças no padrão da expressão das proteínas estruturais. Neste estudo, observamos os efeitos da inibição do hormônio tireóidea (TH e detenção da metamorfose na expressão da E-caderina, ?- e ?- catenina no desenvolvimento do rim do Bufo arenarum. As moléculas de adesão celular durante o desenvolvimento têm uma expressão temporal e espacial seletiva, sugerindo um papel específico na nefrogênese. Com o propósito de estudar os mecanismos de controle da expressão das moléculas de adesão durante o desenvolvimento renal, bloqueou-se a metamorfose do B. arenarum com uma substancia goitrogênica que bloqueia a síntese de TH. A expressão da E-caderina nos tubos proximais é independente do controle da tireóide. Entretanto, o bloqueio da síntese de TH provoca uma sobre elevação da E-caderina nos dutos coletores, nos tubos distais e nos glomérulos. A expressão da ?- e ?-catenina nos dutos coletores, nos tubos distais, nos glomérulos e no mesênquima mesonéfrico é independente da TH. O bloqueio da TH causa uma sobre-regulação da ?- e ?-catenina nos tubos proximais. Em contraste com a E-caderina, a expressão da caderina desmossomal demogloína 1 (Dsg-1 é ausente no controle durante a metamorfose da fase larval dos rins e se expressa em algumas células intersticiais nas larvas tratadas com KClO4. De acordo com este trabalho, a expressão Dsg-1 é subregulada pela TH. Demonstramos que a expressão da E-caderina, Dsg-1, ?-catenina e ?-catenina são afetadas de forma diferencial pelos níveis de TH, sugerindo um dependência hormonal destas proteínas na metamorfose renal do B. arenarum.

  4. Expression of cell adhesion molecules in the normal and T3 blocked development of the tadpole's kidney of Bufo arenarum (Amphibian, Anuran, Bufonidae) / Expressão das moléculas de adesão celular no desenvolvimento normal e com a inibição do hormônio tireoidea do rim nas larvas do Bufo arenarum (Amphibia, Anura, Bufonidae)

    Scientific Electronic Library Online (English)

    MF., Izaguirre; MN., García-Sancho; LA., Miranda; J., Tomas; VH., Casco.

    2008-08-01

    Full Text Available Moléculas de adesão celular atuam como tradutores do ambiente extracelular para o citoesqueleto e o núcleo e, conseqüentemente, induzindo mudanças no padrão da expressão das proteínas estruturais. Neste estudo, observamos os efeitos da inibição do hormônio tireóidea (TH) e detenção da metamorfose na [...] expressão da E-caderina, ?- e ?- catenina no desenvolvimento do rim do Bufo arenarum. As moléculas de adesão celular durante o desenvolvimento têm uma expressão temporal e espacial seletiva, sugerindo um papel específico na nefrogênese. Com o propósito de estudar os mecanismos de controle da expressão das moléculas de adesão durante o desenvolvimento renal, bloqueou-se a metamorfose do B. arenarum com uma substancia goitrogênica que bloqueia a síntese de TH. A expressão da E-caderina nos tubos proximais é independente do controle da tireóide. Entretanto, o bloqueio da síntese de TH provoca uma sobre elevação da E-caderina nos dutos coletores, nos tubos distais e nos glomérulos. A expressão da ?- e ?-catenina nos dutos coletores, nos tubos distais, nos glomérulos e no mesênquima mesonéfrico é independente da TH. O bloqueio da TH causa uma sobre-regulação da ?- e ?-catenina nos tubos proximais. Em contraste com a E-caderina, a expressão da caderina desmossomal demogloína 1 (Dsg-1) é ausente no controle durante a metamorfose da fase larval dos rins e se expressa em algumas células intersticiais nas larvas tratadas com KClO4. De acordo com este trabalho, a expressão Dsg-1 é subregulada pela TH. Demonstramos que a expressão da E-caderina, Dsg-1, ?-catenina e ?-catenina são afetadas de forma diferencial pelos níveis de TH, sugerindo um dependência hormonal destas proteínas na metamorfose renal do B. arenarum. Abstract in english Cell adhesion molecules act as signal transducers from the extracellular environment to the cytoskeleton and the nucleus and consequently induce changes in the expression pattern of structural proteins. In this study, we showed the effect of thyroid hormone (TH) inhibition and arrest of metamorphosi [...] s on the expression of E-cadherin, ?-and ?-catenin in the developing kidney of Bufo arenarum. Cell adhesion molecules have selective temporal and spatial expression during development suggesting a specific role in nephrogenesis. In order to study mechanisms controlling the expression of adhesion molecules during renal development, we blocked the B. arenarum metamorphosis with a goitrogenic substance that blocks TH synthesis. E-cadherin expression in the proximal tubules is independent of thyroid control. However, the blockage of TH synthesis causes up-regulation of E-cadherin in the collecting ducts, the distal tubules and the glomeruli. The expression of ?-and ?-catenin in the collecting ducts, the distal tubules, the glomeruli and the mesonephric mesenchyme is independent of TH. TH blockage causes up-regulation of ?-and ?-catenin in the proximal tubules. In contrast to E-cadherin, the expression of the desmosomal cadherin desmoglein 1 (Dsg-1) is absent in the control of the larvae kidney during metamorphosis and is expressed in some interstitial cells in the KClO4 treated larvae. According to this work, the Dsg-1 expression is down-regulated by TH. We demonstrated that the expression of E-cadherin, Dsg-1, ?-catenin and ?-catenin are differentially affected by TH levels, suggesting a hormone-dependent role of these proteins in the B. arenarum renal metamorphosis.

  5. Species delineation using Bayesian model-based assignment tests: a case study using Chinese toad-headed agamas (genus Phrynocephalus

    Directory of Open Access Journals (Sweden)

    Fu Jinzhong

    2010-06-01

    Full Text Available Abstract Background Species are fundamental units in biology, yet much debate exists surrounding how we should delineate species in nature. Species discovery now requires the use of separate, corroborating datasets to quantify independently evolving lineages and test species criteria. However, the complexity of the speciation process has ushered in a need to infuse studies with new tools capable of aiding in species delineation. We suggest that model-based assignment tests are one such tool. This method circumvents constraints with traditional population genetic analyses and provides a novel means of describing cryptic and complex diversity in natural systems. Using toad-headed agamas of the Phrynocephalus vlangalii complex as a case study, we apply model-based assignment tests to microsatellite DNA data to test whether P. putjatia, a controversial species that closely resembles P. vlangalii morphologically, represents a valid species. Mitochondrial DNA and geographic data are also included to corroborate the assignment test results. Results Assignment tests revealed two distinct nuclear DNA clusters with 95% (230/243 of the individuals being assigned to one of the clusters with > 90% probability. The nuclear genomes of the two clusters remained distinct in sympatry, particularly at three syntopic sites, suggesting the existence of reproductive isolation between the identified clusters. In addition, a mitochondrial ND2 gene tree revealed two deeply diverged clades, which were largely congruent with the two nuclear DNA clusters, with a few exceptions. Historical mitochondrial introgression events between the two groups might explain the disagreement between the mitochondrial and nuclear DNA data. The nuclear DNA clusters and mitochondrial clades corresponded nicely to the hypothesized distributions of P. vlangalii and P. putjatia. Conclusions These results demonstrate that assignment tests based on microsatellite DNA data can be powerful tools for distinguishing closely related species and support the validity of P. putjatia. Assignment tests have the potential to play a significant role in elucidating biodiversity in the era of DNA data. Nonetheless, important limitations do exist and multiple independent datasets should be used to corroborate results from assignment programs.

  6. Anti-inflammatory Drug (Indomethacin and its Effect on Liver Tumor Induced by DMBA

    Directory of Open Access Journals (Sweden)

    N.E. Abdelmeguid

    1999-01-01

    Full Text Available Liver tumors were induced in the toads, Bufo regularis, , in 16 out of 50 cases by the administration of 0.2 mg DMBA/toad, 3 times / week for 12 weeks. Light and electron microscopic photographs demonstrate that these hepatocytes of DMBA - treated toads showed criteria of malignancy. In contrast, toads treated with DMBA at the same dose level and 0.005 per cent w/w indomethacin / toad, 3 times / week for 12 weeks showed a lower incidence of liver tumors, 8 out of 50 cases. The biochemical analysis showed that the activity of G6PD, LDH, acid phosphatase and alkaline phosphatase enzymes were decreased in animals treated with DMBA and indomethacin in comparison with toads treated with DMBA alone. It is concluded that indomethacin has an inhibitory effect on hepatocarcinogenesis in toads.

  7. Arenobufagin, a natural bufadienolide from toad venom, induces apoptosis and autophagy in human hepatocellular carcinoma cells through inhibition of PI3K/Akt/mTOR pathway.

    Science.gov (United States)

    Zhang, Dong-Mei; Liu, Jun-Shan; Deng, Li-Juan; Chen, Min-Feng; Yiu, Anita; Cao, Hui-Hui; Tian, Hai-Yan; Fung, Kwok-Pui; Kurihara, Hiroshi; Pan, Jing-Xuan; Ye, Wen-Cai

    2013-06-01

    Hepatocellular carcinoma (HCC) is a deadly form of cancer without effective chemotherapy so far. Currently, only sorafenib, a multitargeted tyrosine kinase inhibitor, slightly improves survival in HCC patients. In searching for natural anti-HCC components from toad venom, which is frequently used in the treatment of liver cancer in traditional Chinese medicine, we discovered that arenobufagin, a bufadienolide from toad venom, had potent antineoplastic activity against HCC HepG2 cells as well as corresponding multidrug-resistant HepG2/ADM cells. We found that arenobufagin induced mitochondria-mediated apoptosis in HCC cells, with decreasing mitochondrial potential, as well as increasing Bax/Bcl-2 expression ratio, Bax translocation from cytosol to mitochondria. Arenobufagin also induced autophagy in HepG2/ADM cells. Autophagy-specific inhibitors (3-methyladenine, chloroquine and bafilomycin A1) or Beclin1 and Atg 5 small interfering RNAs (siRNAs) enhanced arenobufagin-induced apoptosis, indicating that arenobufagin-mediated autophagy may protect HepG2/ADM cells from undergoing apoptotic cell death. In addition, we observed the inhibition of phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway by arenobufagin. Interestingly, inhibition of mTOR by rapamycin or siRNA duplexes augmented arenobufagin-induced apoptosis and autophagy. Finally, arenobufagin inhibited the growth of HepG2/ADM xenograft tumors, which were associated with poly (ADP-ribose) polymerase cleavage, light chain 3-II activation and mTOR inhibition. In summary, we first demonstrated the antineoplastic effect of arenobufagin on HCC cells both in vitro and in vivo. We elucidated the underlying antineoplastic mechanisms of arenobufagin that involve cross talk between apoptosis and autophagy via inhibition of the PI3K/Akt/mTOR pathway. This study may provide a rationale for future clinical application using arenobufagin as a chemotherapeutic agent for HCC. PMID:23393227

  8. Effects of Acute Restraint Stress, Prolonged Captivity Stress and Transdermal Corticosterone Application on Immunocompetence and Plasma Levels of Corticosterone on the Cururu Toad (Rhinella icterica)

    Science.gov (United States)

    de Assis, Vania Regina; Titon, Stefanny Christie Monteiro; Barsotti, Adriana Maria Giorgi; Titon Jr., Braz; Gomes, Fernando Ribeiro

    2015-01-01

    Glucocorticoid steroids modulate immunocompetence in complex ways with both immunoenhancing and immunosuppressive effects in vertebrates exposed to different stressors. Such bimodal effects have been associated with variation in duration and intensity of the stress response. Given that natural populations have been exposed to a multitude of stressors, a better understanding of the functional association between duration and intensity of the stress response, the resulting changes in glucocorticoid plasma levels and their impact on different aspects of immunocompetence emerges as a cornerstone for vertebrate conservation strategies. We investigated the effects of a restraint challenge (with and without movement restriction), long-term captivity, and transdermal corticosterone application on plasma levels of corticosterone (hereinafter referred to as CORT) and different parameters of innate immunocompetence in the male cururu toads (Rhinella icterica). We show that for R. icterica restraint for 24h proved to be a stressful condition, increasing CORT by 3-fold without consistent immunological changes. However, the application of a more intense stressor (restraint with movement restriction), for the same period, potentiated this response resulting in a 9-fold increase in CORT, associated with increase Neutrophil/Lymphocyte ratio (N:L) and a lower bacterial killing ability (BKA). Transdermal application of corticosterone efficiently mimics repeated acute stress response events, without changing the immune parameters even after 13 days of treatment. Interestingly, long-term captivity did not mitigate the stress response, since the toads maintained 3-fold increased CORT even after 3 months under these conditions. Moreover, long-term captivity in the same condition increased total leukocyte count (TLC) and generated an even greater decrease in BKA, suggesting that consequences of the stress response can be aggravated by time in captivity. PMID:25831055

  9. Hybridization and massive mtDNA unidirectional introgression between the closely related Neotropical toads Rhinella marina and R. schneideri inferred from mtDNA and nuclear markers

    OpenAIRE

    Schneider Horacio; Sampaio Iracilda; Ar, Bernardi Jose?; Ferrand Nuno; Sodré Davidson; Sequeira Fernando; Vallinoto Marcelo

    2011-01-01

    Abstract Background The classical perspective that interspecific hybridization in animals is rare has been changing due to a growing list of empirical examples showing the occurrence of gene flow between closely related species. Using sequence data from cyt b mitochondrial gene and three intron nuclear genes (RPL9, c-myc, and RPL3) we investigated patterns of nucleotide polymorphism and divergence between two closely related toad species R. marina and R. schneideri. By comparing levels of dif...

  10. Applying Fuzzy Logic to Comparative Distribution Modelling: A Case Study with Two Sympatric Amphibians

    OpenAIRE

    Barbosa, A. Ma?rcia; Real, Raimundo

    2012-01-01

    We modelled the distributions of two toads (Bufo bufo and Epidalea calamita) in the Iberian Peninsula using the favourability function, which makes predictions directly comparable for different species and allows fuzzy logic operations to relate different models. The fuzzy intersection between individual models, representing favourability for the presence of both species simultaneously, was compared with another favourability model built on the presences shared by both species. The fuzzy unio...

  11. Aislamiento, clonado y expresión de la proteína recombinante para el factor de crecimiento fibroblástico 8 (FgF-8) de Rhinella (= Bufo) arenarum / Isolation, cloning and expression of the recombinant protein for the fibroblast growth factor 8 (FgF-8) of Rhinella (=Bufo) arenarum

    Scientific Electronic Library Online (English)

    Enrique V., Paravani; María G., Acosta; Javier E., Diaz Zamboni; Víctor H., Casco.

    2009-12-01

    Full Text Available Los estudios embriológicos han demostrado que el origen de los órganos de vertebrados involucra complejas interacciones celulares de diferentes tejidos. Las investigaciones bioquímicas y moleculares, sugieren que las señales endógenas en la cresta ectodérmica apical (AER) ejercidas por el Factor de [...] Crecimiento Fibroblástico 8 (FGF-8), son claves en los procesos de iniciación del desarrollo de los apéndices pares en vertebrados. El objetivo del presente trabajo fue obtener una proteína recombinante para el FGF-8 empleando técnicas moleculares, a partir del aislamiento del gen de Rhinella arenarum y analizar la secuencia nucleotídica con herramientas bioinformáticas. Los resultados reflejaron una estrecha relación evolutiva con genes homólogos de otros anfíbios. La obtención de la proteína recombinante, nos brinda la posibilidad de llevar a cabo estudios estructurales y fisiológicos del FGF-8 durante el desarrollo de los miembros en nuestro modelo animal (R. arenarum). un objetivo secundario fue producir anticuerpos policlonales para buscar otras posibles localizaciones y roles de este factor durante el desarrollo. Abstract in english Embryological studies have demonstrated that the origin of organs in vertebrates involves complex cellular interactions in different tissues. Biochemical and molecular evidence suggests that endogenous signal in the apical ectodermical ridge (AER) are exerted by Fibroblastic Growth Factor 8 (FGF-8). [...] This Factor is essencial in the initiation of the limb development processes in vertebrates. The main objective of the present work was to use molecular techniques to obtain a recombinant protein to FGF-8, from the isolation of the Rhinella arenarum toad gene, and to analyze their nucleotidic sequence using bioinformatic tools. It was possible to express the recombinant FGF-8 in a soluble form and also to study the evolutionary relationship with different vertebrate species. The results reflect a near evolutionary relation with other homologous vertebrates genes, especially with the amphibians. The obtencion of the recombinant protein gave us the possibility of carrying out structural and physiologycal studies about the role of FGF-8 during the limb development in our experimental animal model (R. arenarum). A secondary objective was to produce specific polyclonal antibodies which allowed for the search of other possible locations and roles of this factor during vertebrate development.

  12. Hybridization and massive mtDNA unidirectional introgression between the closely related Neotropical toads Rhinella marina and R. schneideri inferred from mtDNA and nuclear markers

    Directory of Open Access Journals (Sweden)

    Schneider Horacio

    2011-09-01

    Full Text Available Abstract Background The classical perspective that interspecific hybridization in animals is rare has been changing due to a growing list of empirical examples showing the occurrence of gene flow between closely related species. Using sequence data from cyt b mitochondrial gene and three intron nuclear genes (RPL9, c-myc, and RPL3 we investigated patterns of nucleotide polymorphism and divergence between two closely related toad species R. marina and R. schneideri. By comparing levels of differentiation at nuclear and mtDNA levels we were able to describe patterns of introgression and infer the history of hybridization between these species. Results All nuclear loci are essentially concordant in revealing two well differentiated groups of haplotypes, corresponding to the morphologically-defined species R. marina and R. schneideri. Mitochondrial DNA analysis also revealed two well-differentiated groups of haplotypes but, in stark contrast with the nuclear genealogies, all R. schneideri sequences are clustered with sequences of R. marina from the right Amazon bank (RAB, while R. marina sequences from the left Amazon bank (LAB are monophyletic. An Isolation-with-Migration (IM analysis using nuclear data showed that R. marina and R. schneideri diverged at ? 1.69 Myr (early Pleistocene, while R. marina populations from LAB and RAB diverged at ? 0.33 Myr (middle Pleistocene. This time of divergence is not consistent with the split between LAB and RAB populations obtained with mtDNA data (? 1.59 Myr, which is notably similar to the estimate obtained with nuclear genes between R. marina and R. schneideri. Coalescent simulations of mtDNA phylogeny under the speciation history inferred from nuclear genes rejected the hypothesis of incomplete lineage sorting to explain the conflicting signal between mtDNA and nuclear-based phylogenies. Conclusions The cytonuclear discordance seems to reflect the occurrence of interspecific hybridization between these two closely related toad species. Overall, our results suggest a phenomenon of extensive mtDNA unidirectional introgression from the previously occurring R. schneideri into the invading R. marina. We hypothesize that climatic-induced range shifts during the Pleistocene/Holocene may have played an important role in the observed patterns of introgression.

  13. Synergy between glyphosate- and cypermethrin-based pesticides during acute exposures in tadpoles of the common South American toad Rhinella arenarum.

    Science.gov (United States)

    Brodeur, Julie Céline; Poliserpi, María Belén; D'Andrea, María Florencia; Sánchez, Marisol

    2014-10-01

    The herbicide glyphosate and the insecticide cypermethrin are key pesticides of modern management in soy and corn cultures. Although these pesticides are likely to co-occur in ephemeral ponds or aquatic systems supporting amphibian wildlife, the toxicological interactions prevailing in mixtures of these two pesticides have been little studied. The current study evaluated the toxicity of equitoxic and non-equitoxic binary mixtures of glyphosate- and cypermethrin-based pesticides to tadpoles of the common South American toad, Rhinella arenarum. Two different combinations of commercial products were tested: glyphosate Glifosato Atanor®+cypermethrin Xiper® and glyphosate Glifoglex®+cypermethrin Glextrin®. When tested individually, the formulations presented the following 96 h-LC50s: Glifosato Atanor® 19.4 mg ae L(-1) and Glifoglex 72.8 mg ae L(-1), Xiper® 6.8 mg L(-1) and Glextrin® 30.2 mg L(-1). Equitoxic and non-equitoxic mixtures were significantly synergic in both combinations of commercial products tested. The magnitude of the synergy (factor by which toxicity differed from concentration addition) was constant at around twofold for all tested proportions of the glyphosate Glifoglex®+cypermethrin Glextrin® mixture; whereas the magnitude of the synergy varied between 4 and 9 times in the glyphosate Glifosato Atanor®+cypermethrin Xiper® mixture. These results call for more research to be promptly undertaken in order to understand the mechanisms behind the synergy observed and to identify and quantify the extent of its environmental impacts. PMID:25048890

  14. Diet of the toad Rhinella icterica (Anura: Bufonidae) from Atlantic Forest Highlands of southeastern Brazil / Dieta do sapo Rhinella icterica (Anura: Bufonidae) em altitudes elevadas na Mata Atlântica do sudeste do Brasil

    Scientific Electronic Library Online (English)

    Leandro Talione, Sabagh; Ana Maria Paulino Telles, Carvalho-e-Silva; Carlos Frederico Duarte, Rocha.

    2012-12-01

    Full Text Available No presente estudo apresentamos informações sobre o nicho trófico de uma espécie de anuro que reside em altitudes elevadas da Mata Atlântica. Descrevemos a dieta do sapo Rhinella icterica em altitudes acima de 2000 m em áreas de Campos de Altitude no Parque Nacional do Itatiaia. Encontramos 150 iten [...] s nos estômagos analisados de R. icterica, divididos em apenas cinco categorias de presa, além de vestígios da própria pele do anuro e restos vegetais. O índice de importância relativa indicou que besouros e formigas foram os itens mais importantes sendo que formigas representam 70% dos itens ingeridos. A amplitude de nicho trófico (B) foi de 1,81. O reduzido número de categorias alimentares, bem como o elevado número de formigas na dieta sugere que R. icterica apresente uma preferência por este item. Não encontramos nenhuma relação significativa entre as dimensões do anuro com as dimensões das presas. Concluímos que a população de R. icterica que habita os campos de altitude de Itatiaia alimentam-se de artrópodes, principalmente formigas e besouros. O alto consumo de presas com tamanho relativamente semelhante e pequeno como, por exemplo, formigas, impede uma relação esperada entre o tamanho do corpo do anuro ou o tamanho de sua mandíbula e tamanho e volume de presas. Abstract in english In this study, we present some information of the regarding throphic niche from the anuran toad Rhinella icterica living in high altitudes above 2000 m a.s.l. from a habitat of the Atlantic Forest Biome - the Altitude Fields in the Itatiaia National Park. We found 150 prey items in toad stomachs, be [...] longing to five prey types, as well as skin remains and some remains of plant material. The index of relative importance indicated that most important prey types were beetles and ants, these last composing 70% of the diet numerically and the trophic niche breadth (B) was 1.81. The relatively low diversity of prey types we recorded in the diet of R. icterica of Itatiaia and numerically dominated by ants suggests some preference for this item. We do not found significant relationship between the toad measurements with the preys' measurements. We concluded that R. icterica toads at the highlands of Itatiaia feeds on arthropods, mainly ants and coleopterans and that the high consumption of preys with relatively small and similar size as ants in the diet prevents an expected relationship among frog body or mouth size and prey volume and size.

  15. Glycopattern analysis and structure of the egg extra-cellular matrix in the Apennine yellow-bellied toad, Bombina pachypus (Anura: Bombinatoridae

    Directory of Open Access Journals (Sweden)

    Giovanni Scillitani

    2011-07-01

    Full Text Available We studied the glycopatterns and ultrastructure of the extra-cellular matrix (ECM of the egg of theApennine yellow-bellied toad Bombina pachypus, by light and electron microscopy in order to determine structure,chemical composition and function. Histochemical techniques in light microscopy included PAS and AlcianBlue pH 2.5 and 1.0, performed also after b-elimination. Lectin-binding was tested with nine lectins (AAA,ConA, DBA, HPA, LTA, PNA, SBA, UEA-I, WGA. An inner fertilization envelope (FE and five jelly layers(J1–J5 were observed, differing in histochemical staining, lectin binding and ultrastructure. Most glycans wereO-linked, with many glucosamylated and fucosylated residues. The fertilization envelope presented a perivitellinespace and a fertilization layer, with mostly neutral glycans. The jelly layers consisted of fibers and granules,whose number and orientation differed between layers. Fibers were densely packed in J1 and J4 layers,whereas a looser arrangement was observed in the other layers. Jelly-layer glycans were mostly acidic and particularlyabundant in the J1 and J4 layers. In the J1, J2 and J5 layers, neutral, N-linked glycans were also observed.Mannosylated and/or glucosylated as well as galactosyl/galactosaminylated residues were more abundant in theouter layers. Many microorganisms were observed in the J5 layer. We believe that, apart from their functions inthe fertilization process, acidic and fucosylated glycans could act as a barrier against pathogen penetration.

  16. Induction of micronuclei and nuclear abnormalities in tadpoles of the common toad (Rhinella arenarum) treated with the herbicides Liberty® and glufosinate-ammonium.

    Science.gov (United States)

    Lajmanovich, Rafael C; Cabagna-Zenklusen, Mariana C; Attademo, Andrés M; Junges, Celina M; Peltzer, Paola M; Bassó, Agustín; Lorenzatti, Eduardo

    2014-07-15

    The assessment of micronucleated erythrocytes (ME) in blood represents a widely used method for the detection of chromosomal damage by chemical agents, such as herbicides that may occur as water contaminants. We investigated the changes in some circulating blood-cell parameters of tadpoles of the common toad (Rhinella arenarum) that were exposed during 48 or 96 h to three sub-lethal concentrations (3.75, 7.5, and 15 mg/L) of a commercial formulation of a glufosinate-ammonium (GLA)-based herbicide (Liberty(®), LY(®)) as well as to the corresponding active ingredient GLA. The frequency of ME and other erythrocyte nuclear abnormalities (ENA, i.e., lobed nuclei, binucleates or segmented nuclei, kidney-shaped nuclei, notched nuclei, and picnotic nuclei) were evaluated and compared with positive (cyclophosphamide, CP, 40 mg/L) and negative (de-chlorinated tap water) controls. The results indicate that the exposure of R. arenarum tadpoles to LY(®) induces a concentration-dependent increase in ME frequency. The ENA frequency at 48 h was also significantly higher than that in the negative control group for all the chemicals assayed (CP, LY(®) and GLA) whereas at 96 h, increases in ENA over the negative control group were found only for CP and GLA (7.5 mg/L). Our study demonstrates that the commercial formulation of a GLA-based herbicide induces micronucleus formation in R. arenarum tadpoles, in contrast to the active ingredient. According to these results, the inert ingredients of the commercial formulation played an important role in the production of genotoxic damage in erythrocytes of amphibian tadpoles. PMID:24769302

  17. Activated G-protein releases cGMP from high affinity binding sites on PDE from toad rod outer segments (ROS)

    International Nuclear Information System (INIS)

    cGMP binding proteins in toad ROS were identified by direct photoaffinity labeling (PAL) with 32P-cGMP and quantified by retention of complexes on nitrocellulose filters. By PAL, high affinity sites were present on the ? and ? subunits of the cGMP-specific phosphodiesterase (PDE) which have MW/sub app/ of 94 and 90 kDa. A doublet was deduced from its photolabeling properties to represent PDE/sub ?/ photocrosslinked with PDE/sub ?/ or PDE/sub ?/, respectively. cGMP prebound to these high affinity sites was released by light-activated G-protein or its ? subunit complexed with GTP?S; this inhibition of cGMP binding to PDE did not result from decreased cGMP availability due to enhanced hydrolysis. A low affinity cGMP binding component identified by PAL is tightly associated with ROS membranes. Apparent ATP/light-dependent stimulation of cGMP binding was shown to result from light activated cGMP hydrolysis in conjunction with ATP-promoted conversion of GMP to GDP/GTP and increased GDP/GTP binding. These findings coincide with a model for light-related regulation of cGMP binding and metabolism predicted from intact and cellfree kinetic measurements: in the dark state the cGMP hydrolic rate is constrained by the availability of cGMP because of its binding to high affinity sites on PDE. Light activated G-protein releases cGMP from these sites and allows for its redistribution to lower affinity sites represented by PDE catalytic site(s) and possible cGMP-depeytic site(s) and possible cGMP-dependent membrane cation channels

  18. Lueheia inscripta (Westrumb, 1821) (Acanthocephala: Plagiorhynchidae) in anurans (Leptodactylidae: Bufonidae) from Mexico.

    Science.gov (United States)

    Salgado-Maldonado, G; Caspeta-Mandujano, J M

    2010-06-01

    Juveniles of Lueheia inscripta (Westrumb, 1821 Travassos, 1919 (Acanthocephala: Plagiorhynchidae), an acanthocephalan with six lemnisci, are reported and described from mesenteries of frogs Leptodactylus fragilis Brochi, 1877 and a toad Bufo marinus (Linnaeus, 1758) from Morelos state, Mexico. These are new host records extending the known geographical distribution of this species from Brazil and Puerto Rico to Mexico. PMID:20597444

  19. Membrane potentials and intracellular Cl- activity of toad skin epithelium in relation to activation and deactivation of the transepithelial Cl- conductance

    DEFF Research Database (Denmark)

    Willumsen, N J; Larsen, Erik Hviid

    1986-01-01

    The potential dependence of unidirectional 36Cl fluxes through toad skin revealed activation of a conductive pathway in the physiological region of transepithelial potentials. Activation of the conductance was dependent on the presence of Cl or Br in the external bathing solution, but was independent of whether the external bath was NaCl-Ringer's, NaCl-Ringer's with amiloride, KCl-Ringer's or choline Cl-Ringer's. To partition the routes of the conductive Cl- ion flow, we measured in the isolated epithelium with double-barrelled microelectrodes apical membrane potential. Va, and intracellular Cl- activity, acCl, of the principal cells identified by differential interference contrast microscopy. Under short-circuit conditions, Isc = 27.0 +/- 2.0 microA/cm2, with NaCl-Ringer's bathing both surfaces, Va was -67.9 +/- 3.8 mV (mean +/- SE, n = 24, six preparations) and acCl was 18.0 +/- 0.9 mM in skins from animals adapted to distilled water. Both Va and acCl were found to be positively correlated with Isc (r = 0.66 and r = 0.70, respectively). In eight epithelia from animals adapted to dry milieu/tap water Va and acCl were measured with KCl Ringer's on the outside during activation and deactivation of the transepithelial Cl- conductance (GCl) by voltage clamping the transepithelial potential (V) at 40 mV (mucosa positive) and -100 mV. At V = 40 mV; i.e. when GCl was deactivated, Va was -70.1 +/- 5.0 mV (n = 15, eight preparations) and acCl was 40.0 +/- 3.8 mM. The fractional apical membrane resistance (fRa) was 0.69 +/- 0.03. Clamping to V = -100 mV led to an instantaneous change of Va to 31.3 +/- 5.6 mV (cell interior positive with respect to the mucosal bath), whereas neither acCl nor fRa changed significantly within a 2 to 5-min period during which GCl increased by 1.19 +/- 0.10 mS/cm2. When V was stepped back to 40 mV, Va instantaneously shifted to -67.8 +/- 3.9 mV while acCl and fRa remained constant during deactivation of GCl. Similar results were obtained in epithelia impaled from the serosal side. In 12 skins from animals adapted to either tap water or distilled water the density of mitochondria-rich (DMRC) cells was estimated and correlated with the Cl current (ICl through the fully activated (V = -100 mV) Cl conductance). A highly significant correlation ws revealed (r = -0.96) with a slope of -2.6 nA/m.r. (mitochondria-rich cell and an I-axis intercept not significantly different from zero.(ABSTRACT TRUNCATED AT 400 WORDS)

  20. Perpetual production of hair cells and maturational changes in hair cell ultrastructure accompany postembryonic growth in an amphibian ear.

    OpenAIRE

    Corwin, J. T.

    1985-01-01

    Sensory hair cells are produced in the ears of birds and mammals only during early development, so that a programmed termination of hair cell proliferation leaves adult birds and mammals susceptible to irreversible deafness and balance disorders. This study reports that this is not an inherent feature of hair cells and is not shared through all the vertebrate classes. In toads (Bufo marinus) hair cells accumulate throughout life, increasing in the sacculus from approximately 400 cells at meta...

  1. Characterization of cross-bridge elasticity and kinetics of cross-bridge cycling during force development in single smooth muscle cells

    OpenAIRE

    Warshaw, Dm; Rees, Dd; Fay, Fs

    1988-01-01

    Force development in smooth muscle, as in skeletal muscle, is believed to reflect recruitment of force-generating myosin cross-bridges. However, little is known about the events underlying cross-bridge recruitment as the muscle cell approaches peak isometric force and then enters a period of tension maintenance. In the present studies on single smooth muscle cells isolated from the toad (Bufo marinus) stomach muscularis, active muscle stiffness, calculated from the force response to small sin...

  2. Cross-bridge elasticity in single smooth muscle cells

    OpenAIRE

    1983-01-01

    In smooth muscle, a cross-bridge mechanism is believed to be responsible for active force generation and fiber shortening. In the present studies, the viscoelastic and kinetic properties of the cross- bridge were probed by eliciting tension transients in response to small, rapid, step length changes (delta L = 0.3-1.0% Lcell in 2 ms). Tension transients were obtained in a single smooth muscle cell isolated from the toad (Bufo marinus) stomach muscularis, which was tied between a force transdu...

  3. Comparative Analysis of the Bufonis Venenum by Using TLC, HPLC, and LC-MS for Different Extraction Methods

    Directory of Open Access Journals (Sweden)

    Lee Hyo-Jae

    2012-12-01

    Full Text Available Objectives: Toad venom, called Chan-Su, is a traditional Oriental medicine secreted from the auricular and the skin glands of the Bufo bufo gargarizanz Cantor or B. melanosticus Schneider and has been widely used in China, Korea and other parts of Asia for the treatment of pain, heart conditions, and cancer. We examined the concentrations of the main chemical constituents within a commerciallyavailable toad venom product and compared the levels for different extraction methods. Methods: Toad venom was extracted using either cold or hot water, ethanol (EtOH, methanol (MeOH, or ethyl acetate (EtOAc, was fractionated using precipitation or reflux, and was then analyzed using thin layer chromatography (TLC, high-performance liquid chromatography (HTLC, and liquid chroma-tography - mass spectrometry (LC-MS. Individual components were identified by comparisons of the retention times, the ultraviolet spectra, and mass spectras and differences in chemical constituents for different solvents and extraction methods are presented. Results:Components with authentic standards, including serotonin and bufodienolides (cinobufagen, bufalin, cinobufalin, and resibufogenin, were detected. The water extract of toad venom contained the greatest amount of serotonin (75.7 ± 0.1 mg/g, but very small amounts of bufodienolides (3.8 ± 0.0 mg/g. In contrast, the use of MeOH or EtOH extraction solutions resulted in 5-26 times higher concentrations of bufodienolides, with only trace amounts of serotonin. The relative and the absolute concentrations of the component also varied based on the extraction method; i.e., EtOH extracts yielded the greatest total amounts of bufodienolides, and EtOAc precipitation had the lowest amounts of bufodienolides. Conclusions: Toad venom consists of serotonin and several bufodienolides, and the choice of solvent to extract chemical the constituents is important as a way to enrich the purported active components for treating different conditions.

  4. How does exposure to the fungus Batrachochytrium dendrobatidis affects the tadpoles of the common tode, Bufo bufo, under different stresses?

    OpenAIRE

    Patri?cio, Pedro Miguel Brilha

    2014-01-01

    Os anfíbios enfrentam uma crise de extinção em massa e são atualmente considerados um dos grupos mais ameaçados de vertebrados. O atual declínio global deste grupo é causado por múltiplos fatores, e um dos mais importantes é a propagação do fungo Batrachochytrium dendrobatidis (Bd), que já foi documentado como agente infecioso em 350 espécies de anfíbios. Genericamente a sobrevivência das larvas de anfíbios é afectada por factores bióticos e abióticos. Como factores biótic...

  5. Influenza em animais heterotérmicos Influenza in heterothermics

    Directory of Open Access Journals (Sweden)

    Dalva Assunção Portari Mancini

    2004-06-01

    Full Text Available O objetivo foi pesquisar Ortomyxovirus em animais heterotérmicos. Coletou-se sangue de serpentes dos gêneros Bothrops e Crotalus e de sapo e rãs dos gêneros Bufo e Rana, para a detecção dos receptores de hemácias e anticorpos específicos, ao vírus influenza, pelos testes de hemaglutinação e inibição da hemaglutinação, respectivamente. Pelo teste de hemaglutinação, verificou-se que serpentes e sapos em cativeiro apresentaram receptores em suas hemácias para o vírus influenza, humano e eqüino do tipo A e tipo B. O mesmo ocorreu com serpentes recém chegadas. Quanto ao teste de inibição da hemaglutinação dos soros dos répteis observou-se títulos protetores de anticorpos aos vírus influenza tipo A (origens humana e eqüina e tipo B. Com soro de sapo não se observou reação de inibição da hemaglutinação porém, 83,3% das rãs obtiveram médias de 40UIH para algumas cepas. Conclui-se que animais heterotérmicos podem oferecer condições de hospedeiros aos vírus influenza, assim como susceptibilidade à infecção.The objective was to study Orthomyxovirus in heterothermic animals. Blood samples from snakes (genus Bothrops and Crotalus and from toads and frogs (genus Bufo and Rana were collected to evaluate the red cell receptors and antibodies specific to influenza virus by the hemagglutination and hemagglutination inhibition tests, respectively. Both snakes and toads kept in captivity presented receptors in their red cells and antibodies specific to either influenza virus type A (human and equine origin or influenza type B. The same was observed with recently captured snakes. Concerning the influenza hemagglutination inhibition antibodies protective levels were observed in the reptiles' serum, against influenza type A and type B. Unlike the toads, 83.3% of the frogs presented mean levels of Ab 40HIU for some influenza strains. It was concluded that heterothermic animals could offer host conditions to the influenza virus and also susceptibility to the infection.

  6. Insulin-stimulated Na+ transport in a model renal epithelium: protein synthesis dependence and receptor interactions

    International Nuclear Information System (INIS)

    The urinary bladder of the toad, Bufo marinus, is a well characterized model of the mammalian distal nephron. Porcine insulin (? 0.5-5.0 ?M) stimulates net mucosal to serosal Na+ flux within 10 minutes of hormone addition. The response is maintained for at least 5 hr and is completely abolished by low doses (10?M) of the epithelial Na+ channel blocker amiloride. Insulin-stimulated Na+ transport does not require new protein synthesis since it is actinomycin-D (10?g/ml) insensitive. Also in 3 separate experiments in which epithelial cell proteins were examined by 35S-methionine labeling, 2-dimensional polyacrylamide gel electrophoresis/autoradiography, no insulin induced proteins were observed. Equimolar concentrations of purified porcine proinsulin and insulin (0.64?M) stimulate Na+ transport to the same extent. Thus, the putative toad insulin receptor may have different affinity characteristics than those demonstrated for insulin and proinsulin in mammalian tissues. Alternatively, the natriferic action of insulin in toad urinary bladders may be mediated by occupancy of another receptor. Preliminary experiments indicating that nanomolar concentrations of IGF1 stimulate Na+ transport in this tissue support the latter contention

  7. Metamorphosis of two amphibian species after chronic cadmium exposure in outdoor aquatic mesocosms

    Science.gov (United States)

    James, S.M.; Little, E.E.; Semlitsch, R.D.

    2005-01-01

    Amphibian larvae at contaminated sites may experience an alteration of metamorphic traits and survival compared to amphibians in uncontaminated conditions. Effects of chronic cadmium (Cd) exposure on the metamorphosis of American toads (Bufo americanus) and southern leopard frogs (Rana sphenocephala) were determined. The two species were reared separately from shortly after hatching through metamorphosis in outdoor mesocosms (1,325-L polyethylene cattle tanks) that simulated natural ponds and enhanced environmental realism relative to the laboratory. Both species exhibited a decrease in survival with increasing initial nominal aqueous Cd concentration. Cadmium treatment did not influence mass at metamorphosis for either species when survival was included as a covariate, but increased the age at metamorphosis for the American toads. The whole body Cd content of metamorphs increased with aqueous Cd treatment level for both species, and the American toads tended to possess more elevated residues. Cadmium quickly partitioned out of the water column and accumulated in and altered the abundance of the tadpoles' diet. Cadmium-contaminated sites may produce fewer metamorphs, and those that survive will metamorphose later and contain Cd. Interspecific differences in the response variables illustrate the importance of testing multiple species when assessing risk. ?? 2005 SETAC.

  8. Sympatric Masticophis flagellum and Coluber constrictor select vertebrate prey at different levels of taxonomy

    Science.gov (United States)

    Halstead, B.J.; Mushinsky, H.R.; McCoy, E.D.

    2008-01-01

    Masticophis flagellum (Coachwhip) and Coluber constrictor (Eastern Racer) are widespread North American snakes with similar foraging modes and habits. Little is known about the selection of prey by either species, and despite their apparently similar foraging habits, comparative studies of the foraging ecology of sympatric M. flagellum and C. constrictor are lacking. We examined the foraging ecology and prey selection of these actively foraging snakes in xeric, open-canopied Florida scrub habitat by defining prey availability separately for each snake to elucidate mechanisms underlying geographic, temporal, and interspecific variation in predator diets. Nineteen percent of M. flagellum and 28% of C. constrictor contained stomach contents, and most snakes contained only one prey item. Mean relative prey mass for both species was less than 10%. Larger C. constrictor consumed larger prey than small individuals, but this relationship disappeared when prey size was scaled to snake size. Masticophis flagellum was selective at the prey category level, and positively selected lizards and mammals; however, within these categories it consumed prey species in proportion to their availability. In contrast, C. constrictor preyed upon prey categories opportunistically, but was selective with regard to species. Specifically, C. constrictor positively selected Hyla femoralis (Pine Woods Treefrog) and negatively selected Bufo querclcus (Oak Toad), B. terrestris (Southern Toad), and Gastrophryne carolinensis (Eastern Narrowmouth Toad). Thus, despite their similar foraging habits, M. flagellum and C. constrictor select different prey and are selective of prey at different levels of taxonomy. ?? 2008 by the American Society of Ichthyologists and Herpetologists.

  9. All-Optical Reversible Hybrid New Gate using TOAD

    Directory of Open Access Journals (Sweden)

    Goutam Kumar Maity

    2014-03-01

    Full Text Available Reversible logic is emerged as a promising computing paradigm with applications in low-power CMOS, quantum computing, optical computing and nanotechnology. Optical logic gates become potential component to work at macroscopic (light pulses carry information, or quantum (single photon carries information levels with high efficiency. In this paper, we propose a novel scheme of Hybrid new gate realization in all-optical domain. Simulation results verify the functionality of the gate as well as reversibility. Approximate insertion power loss in dB is also reported for the Gaussian incident and control pulse.

  10. Disappearance of boreal toads in Colorado: A contaminant investigation

    US Fish and Wildlife Service, Department of the Interior — Population sizes of many, but not all, amphibian species have experienced declines on all six continents on which they occur Phillips 1990, Vial and Saylor 1993....

  11. Nuevas localidades para Bufo fernandezae Gallardo, 1957 en el centro de Argentina

    Directory of Open Access Journals (Sweden)

    Torres, R. M.

    2000-05-01

    Full Text Available REP. ARGENTINA, PROVINCIA DE CÓRDOBA, Feb. 1985. Dpto. San Justo, Cañada de Jeanmaire, 31° 24' S, 62° 28' W. 1 individuo. Museo de Zoología de la Fac. Cs. Ex. Fís. y Nat., Univ. Nac. Córdoba (MZUC 2115: 74. Colectores: J. G. Haro y M. A. Bistoni. Ene. 1997. Desembocadura del río Plujunta en la laguna Mar Chiquita, 30° 55' S, 62° 44' W. 2 individuos. MZUC 2115: 88, 89. Colector. R. M. Torres. PROVINCIA DE SANTIAGO DEL ESTERO, Mar. 1997. Dpto. Quebrachos, Paso de la Cina, 29° 49' S, 62° 48' W. 1 individuo. MZUC 2115: 90. Colector: M. Sironi.

  12. Monitoring programs to assess reintroduction efforts: A critical component in recovery

    Science.gov (United States)

    Muths, E.; Dreitz, V.

    2008-01-01

    Reintroduction is a powerful tool in our conservation toolbox. However, the necessary follow-up, i.e. long-term monitoring, is not commonplace and if instituted may lack rigor. We contend that valid monitoring is possible, even with sparse data. We present a means to monitor based on demographic data and a projection model using the Wyoming toad (Bufo baxten) as an example. Using an iterative process, existing data is built upon gradually such that demographic estimates and subsequent inferences increase in reliability. Reintroduction and defensible monitoring may become increasingly relevant as the outlook for amphibians, especially in tropical regions, continues to deteriorate and emergency collection, captive breeding, and reintroduction become necessary. Rigorous use of appropriate modeling and an adaptive approach can validate the use of reintroduction and substantially increase its value to recovery programs. ?? 2008 Museu de Cie??ncies Naturals.

  13. Ground Water Chemistry Changes before Major Earthquakes and Possible Effects on Animals

    Directory of Open Access Journals (Sweden)

    Rachel A. Grant

    2011-06-01

    Full Text Available Prior to major earthquakes many changes in the environment have been documented. Though often subtle and fleeting, these changes are noticeable at the land surface, in water, in the air, and in the ionosphere. Key to understanding these diverse pre-earthquake phenomena has been the discovery that, when tectonic stresses build up in the Earth’s crust, highly mobile electronic charge carriers are activated. These charge carriers are defect electrons on the oxygen anion sublattice of silicate minerals, known as positive holes, chemically equivalent to O– in a matrix of O2–. They are remarkable inasmuch as they can flow out of the stressed rock volume and spread into the surrounding unstressed rocks. Travelling fast and far the positive holes cause a range of follow-on reactions when they arrive at the Earth’s surface, where they cause air ionization, injecting massive amounts of primarily positive air ions into the lower atmosphere. When they arrive at the rock-water interface, they act as •O radicals, oxidizing water to hydrogen peroxide. Other reactions at the rock-water interface include the oxidation or partial oxidation of dissolved organic compounds, leading to changes of their fluorescence spectra. Some compounds thus formed may be irritants or toxins to certain species of animals. Common toads, Bufo bufo, were observed to exhibit a highly unusual behavior prior to a M6.3 earthquake that hit L’Aquila, Italy, on April 06, 2009: a few days before the seismic event the toads suddenly disappeared from their breeding site in a small lake about 75 km from the epicenter and did not return until after the aftershock series. In this paper we discuss potential changes in groundwater chemistry prior to seismic events and their possible effects on animals.

  14. EXPERIMENTAL MODEL TO INVESTIGATE DRUGS FOR EPILEPSY

    Directory of Open Access Journals (Sweden)

    Jesús Carlos Ruvalcaba Ledezma

    2013-09-01

    Full Text Available Introduction.Epilepsy is one of the most common neurological disorders characterized by seizures. Epileptic seizures result from excessive, abnormal, or hyper synchronous neuronal activity in the brain. It is a public health problem that is not yet curable but which can be controlled. A high percentage of patients who suffer from epilepsy do not have seizures control even when using the existing treatments. Therefore, an experimental study was conducted with the objective of determining the effect of the Bufo-toxin in rats belonging to the BALB/c and the Wistar strainsin order to diagnose the group of symptoms that confer lethality to this toxin and which can work as a treatment to such disease.Methodology the bufo-toxin was obtained from toads, then it was placedin alcoholic solution and it was applied to the rats in doses of 5 by 5 for up to 20 Units with an insulin syringe though the intramuscular via. Observations were registered and when the rats died a post-mortem examination was conducted in order to describe the effect of the toxin in the internal organs. Results. The rats that were inoculated within 20 units of the toxin showed epileptic seizures and finally cerebral spill or heart attack. Discussion and conclusion. This model can be used to investigate on useful drugs against epilepsy and even heart diseases, such as, hypertension andheart attacks.

  15. Spatial and structural interrelationships between secretory cells of the subcommissural organ and blood vessels. An immunocytochemical study.

    Science.gov (United States)

    Rodríguez, E M; Oksche, A; Hein, S; Rodríguez, S; Yulis, R

    1984-01-01

    In 76 specimens (amphibians, reptilians, mammals) belonging to 25 different vertebrate species, the region of the subcommissural organ (SCO) was investigated with the use of a primary antiserum raised against an extract of bovine Reissner's fiber + the immunoperoxidase procedure according to Sternberger et al. (1970). In the SCO of a toad (Bufo arenarum) and several species of reptiles (lacertilians, ophidians, crocodilians), the ependymal cells were the only type of secretory cell displaying vascular contacts, whereas in mammals ependymal and hypendymal cells established intimate spatial contacts with blood vessels. In Bufo arenarum, but especially in the reptilian species examined, the ependymo-vascular relationship was exerted by a population of ependymal cells having a rather constant location within the SCO and projecting to capillaries that showed a remarkably constant pattern of anatomical distribution. In the SCO of mammals the modality and degree of the structural relationships between secretory cells and blood vessels varied greatly from species to species. In the SCO of the armadillo and dog the secretory tissue was organized as a thick, highly vascularized layer with most of the cells oriented toward the capillaries. A rather opposite situation was found in the SCO of New- and Old-World monkeys, where vascular contacts were restricted to a few ependymal cells. PMID:6435877

  16. Combined exposure to ambient UVB radiation and nitrite negatively affects survival of amphibian early life stages

    Energy Technology Data Exchange (ETDEWEB)

    Macias, Guadalupe [Donana Biological Station, CSIC, Spanish Council for Scientific Research. P.O. Box 1056, Sevilla 41013 (Spain); Marco, Adolfo [Donana Biological Station, CSIC, Spanish Council for Scientific Research. P.O. Box 1056, Sevilla 41013 (Spain)], E-mail: amarco@ebd.csic.es; Blaustein, Andrew R. [Department of Zoology, Oregon State University, Corvallis, Oregon, 97331 (United States)

    2007-10-15

    Many aquatic species are sensitive to ambient levels of ultraviolet-B radiation (UVB) and chemical fertilizers. However, recent studies indicate that the interaction among multiple stressors acting simultaneously could be contributing to the population declines of some animal species. Therefore, we tested the potential synergistic effects between ambient levels of UVB and a contaminant, sodium nitrite in the larvae of two amphibian species, the common European toad Bufo bufo and the Iberian green frog Rana perezi. We studied R. perezi from both mountain and coastal populations to examine if populations of the same species varied in their response to stressors in different habitats. Both species were sensitive to the two stressors acting alone, but the interaction between the two stressors caused a multiplicative impact on tadpole survival. For B. bufo, the combination of UVB and nitrite was up to seven times more lethal than mortality for each stressor alone. In a coastal wetland, the combination of UVB and nitrite was four times more toxic for R. perezi than the sum of the effect on mortality for each stressor alone. One mg/L of nitrite killed half the population of R. perezi at Gredos Mountains at day 10 in the absence of UVB. In the presence of UVB, 50% of the tadpoles from the same experiment died at day 7. Similar toxic response were found for R. perezi in two highly contrasted environments suggesting this synergistic interaction can be a widespread phenomenon. The interaction of excess chemical fertilizers and manure with ambient UVB radiation could be contributing to the global decline of some amphibian species. We suggest that potential exposure to UVB radiation be accounted for when assessing water quality criteria regarding nitrite pollution.

  17. Combined exposure to ambient UVB radiation and nitrite negatively affects survival of amphibian early life stages

    International Nuclear Information System (INIS)

    Many aquatic species are sensitive to ambient levels of ultraviolet-B radiation (UVB) and chemical fertilizers. However, recent studies indicate that the interaction among multiple stressors acting simultaneously could be contributing to the population declines of some animal species. Therefore, we tested the potential synergistic effects between ambient levels of UVB and a contaminant, sodium nitrite in the larvae of two amphibian species, the common European toad Bufo bufo and the Iberian green frog Rana perezi. We studied R. perezi from both mountain and coastal populations to examine if populations of the same species varied in their response to stressors in different habitats. Both species were sensitive to the two stressors acting alone, but the interaction between the two stressors caused a multiplicative impact on tadpole survival. For B. bufo, the combination of UVB and nitrite was up to seven times more lethal than mortality for each stressor alone. In a coastal wetland, the combination of UVB and nitrite was four times more toxic for R. perezi than the sum of the effect on mortality for each stressor alone. One mg/L of nitrite killed half the population of R. perezi at Gredos Mountains at day 10 in the absence of UVB. In the presence of UVB, 50% of the tadpoles from the same experiment died at day 7. Similar toxic response were found for R. perezi in two highly contrasted environments suggesting this synergistic interaction can be a widespread phenomenon. Teraction can be a widespread phenomenon. The interaction of excess chemical fertilizers and manure with ambient UVB radiation could be contributing to the global decline of some amphibian species. We suggest that potential exposure to UVB radiation be accounted for when assessing water quality criteria regarding nitrite pollution

  18. Biological response to climate change on a tropical mountain

    Science.gov (United States)

    Pounds, J. Alan; Fogden, Michael P. L.; Campbell, John H.

    1999-04-01

    Recent warming has caused changes in species distribution and abundance, but the extent of the effects is unclear. Here we investigate whether such changes in highland forests at Monteverde, Costa Rica, are related to the increase in air temperatures that followed a step-like warming of tropical oceans in 1976 (refs4, 5). Twenty of 50 species of anurans (frogs and toads) in a 30-km2 study area, including the locally endemic golden toad (Bufo periglenes), disappeared following synchronous population crashes in 1987 (refs 6-8). Our results indicate that these crashes probably belong to a constellation of demographic changes that have altered communities of birds, reptiles and amphibians in the area and are linked to recent warming. The changes are all associated with patterns of dry-season mist frequency, which is negatively correlated with sea surface temperatures in the equatorial Pacific and has declined dramatically since the mid-1970s. The biological and climatic patterns suggest that atmospheric warming has raised the average altitude at the base of the orographic cloud bank, as predicted by the lifting-cloud-base hypothesis,.

  19. Helminth communities in five species of sympatric amphibians from three adjacent ephemeral ponds in southeastern Wisconsin.

    Science.gov (United States)

    Yoder, H Randall; Coggins, James R

    2007-08-01

    Representatives of 5 amphibian species (313 individuals), including eastern American toads (Bufo americanus), wood frogs (Rana sylvatica), spring peepers (Pseudacris crucifer), blue-spotted salamanders (Ambystoma laterale), and central newts (Notophthalmus viridescens louisianensis), were collected from 3 ephemeral ponds during spring 1994, and they were inspected for helminth parasites. The component communities of anurans were more diverse than those of caudates. Infracommunities of all host species were isolationist and depauperate, due mostly to host ectothermy and low vagility. Toad infracommunities were dominated by skin-penetrating nematodes, and they had the highest values of mean total parasite abundance, mean species richness, and overall prevalence. This was likely due to their greater vagility compared with other host species. Infracommunities of wood frogs and blue-spotted salamanders had intermediate values for these measures of parasitism, whereas spring peeper and newt infracommunities had the lowest values. In addition to relative vagility, feeding habits and habitat preference were likely important in helminth community structure. Body size also seemed to play a role because mean wet weight of host species followed the same general trend as values of parasitism. However, effects of size were variable within host species and difficult to separate from other aspects of host ecology. PMID:17918353

  20. Toxicity of road salt to Nova Scotia amphibians

    International Nuclear Information System (INIS)

    The deposition of chemical pollutants into roadside wetlands from runoff is a current environmental concern. In northern latitudes, a major pollutant in runoff water is salt (NaCl), used as de-icing agents. In this study, 26 roadside ponds were surveyed for amphibian species richness and chloride concentration. Acute toxicity tests (LC50) were performed on five locally common amphibian species using a range of environmentally significant NaCl concentrations. Field surveys indicated that spotted salamanders (Ambystoma maculatum) and wood frogs (Rana sylvatica) did not occupy high chloride ponds. American toads (Bufo americanus) showed no pond preference based on chloride concentration. Acute toxicity tests showed spotted salamanders and wood frogs were most sensitive to chloride, and American toads were the least. Spring peepers (Pseudacris crucifer) and green frogs (Rana clamitans) showed intermediate sensitivities. We concluded that chloride concentrations in ponds due to application of de-icing salts, influenced community structure by excluding salt intolerant species. - Salt toxicity is presented as a mechanism affecting the distribution of amphibians and structure of amphibian communities in roadside wetlands

  1. Toxicity of road salt to Nova Scotia amphibians

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Sara J. [Department of Biology, Saint Mary' s University, 923 Robie Street, Halifax, NS, B3H 3C3 (Canada); Russell, Ronald W. [Department of Biology, Saint Mary' s University, 923 Robie Street, Halifax, NS, B3H 3C3 (Canada)], E-mail: ron.russell@smu.ca

    2009-01-15

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

  2. 78 FR 27249 - Endangered Species Recovery Permit Applications

    Science.gov (United States)

    2013-05-09

    ...a. southwestern t.) (Anaxyrus californicus (Bufo microscaphus c.)) in conjunction...a. southwestern t.) (Anaxyrus californicus (Bufo microscaphus c.)) in conjunction...a. southwestern t.) (Anaxyrus californicus (Bufo microscaphus c.)) in...

  3. Paleoclimatic and paleoenvironmental context of the Early Pleistocene hominins from Dmanisi (Georgia, Lesser Caucasus) inferred from the herpetofaunal assemblage

    Science.gov (United States)

    Blain, Hugues-Alexandre; Agustí, Jordi; Lordkipanidze, David; Rook, Lorenzo; Delfino, Massimo

    2014-12-01

    Dmanisi is currently the oldest Early Palaeolithic site discovered out of Africa. It has produced over 40 hominin remains, including a set of very informative skulls, in direct association with faunal remains and numerous lithic artifacts. Given the relevance of this locality, every effort is being made to reconstruct the landscapes where these hominins once lived. Amphibian and reptile remains from Dmanisi are here described for the first time and used as paleoclimatic and paleoenvironmental proxies. They comprise at least six taxa: a green toad (Bufo gr. Bufo viridis), the Greek tortoise (Testudo graeca), a green lizard (Lacerta gr. Lacerta viridis), a four-lined snake (Elaphe gr. Elaphe quatuorlineata), an indeterminate colubrid and a water snake (Natrix sp.). As these taxa are not extinct and their ecology can be directly studied, they can contribute to the reconstruction of the landscape and climate. The application of the Mutual Climatic Range method provides quantitative data indicating that during the hominin presence at Dmanisi climate was warm and dry, similar to the present-day Mediterranean climate. In comparison with today climate of Dmanisi, estimated mean annual temperature was 3.1 °C higher, with a greater increase of temperature in summer (+7.1 °C) than in winter (+4.7 °C). The mean annual precipitation was slightly lower (-65 mm) than the current level, with precipitation higher than current one during winter (+104 mm) but strongly lower during the other seasons, suggesting a stronger contrast in the rainfall regime during the year. From a paleoenvironmental point of view, fossil amphibians and reptiles all suggest the predominance of arid environments, from steppe or semi-desert to open Mediterranean forest, with stony or rocky substrate and bushy areas. The presence of permanent aquatic environments is also documented. These results mainly agree with those for large mammals, small mammals and the archaeobotanical analysis that indicate an important water stress suggesting a period of increased aridity contemporaneous with human occupations of the site.

  4. Keystone predators (eastern newts, Notophthalmus viridescens) reduce the impacts of an aquatic invasive species

    Science.gov (United States)

    Smith, Kimberly G.

    2006-01-01

    Predation, competition, and their interaction are known to be important factors that influence the structure of ecological communities. In particular, in those cases where a competitive hierarchy exists among prey species, the presence of certain keystone predators can result in enhanced diversity in the prey community. However, little is known regarding the influence of keystone predator presence on invaded prey communities. Given the widespread occurrence of invasive species and substantial concern regarding their ecological impacts, studies on this topic are needed. In this study I used naturalistic replications of an experimental tadpole assemblage to assess the influence of predatory eastern newts, Notophthalmus viridescens, on the outcome of interspecific competition among native and nonindigenous tadpoles. When newts were absent, the presence of the tadpoles of one invasive species, the Cuban treefrog, Osteopilus septentrionalis, resulted in decreased survival and growth rate of the dominant native species, Bufo terrestris, and dominance of the tadpole assemblage by O. septentrionalis. However, the presence of one adult newt generally reduced or eliminated the negative impacts of O. septentrionalis tadpoles, resulting in comparable survival and performance of native species in invaded and noninvaded treatments. Differential mortality among the tadpole species suggests that newts preyed selectively on O. septentrionalis tadpoles, supporting the hypothesis that newts acted as keystone predators in the invaded assemblage. The presence of nonindigenous larval cane toads, Bufo marinus, did not significantly affect native species, and this species was not negatively affected by the presence of newts. Collectively, these results suggest that eastern newts significantly modified the competitive hierarchy of the invaded tadpole assemblage and reduced the impacts of a competitively superior invasive species. If general, these results suggest that the presence of certain species may be an essential factor regulating the ecological impacts of biological invasions.

  5. Enthalpic consequences of reduced chloride binding in Andean frog (Telmatobius peruvianus) hemoglobin

    DEFF Research Database (Denmark)

    Weber, Roy E.

    2014-01-01

    Based on the exothermic nature of heme oxygenation, the O2 affinity of hemoglobin (Hb) decreases with increasing temperature, which may be physiologically advantageous in augmenting O2 unloading from blood in warm tissues with elevated metabolic rates. This negative oxygenation enthalpy (?H (O)) may, however, become maladaptive, as in cold-tolerant ungulates where it may hamper O2 unloading in cold extremities and commonly is mitigated by an 'additional' chloride-binding site that decreases the temperature effect by increasing the endothermic release of Cl(-) ions upon O2 binding. Since no previous studies have focused on the consequences of reduced Cl(-) binding, I report and compare the enthalpic effects of chloride ions and the allosteric effector, ATP, on Hbs of the high-altitude aquatic Andean frog Telmatobius peruvianus that lacks the ?-chain chloride-binding site, and the lowland (sub-)tropical frog Xenopus laevis that has retained this site and exhibits high chloride sensitivity. In contrast to Xenopus, Telmatobius Hb exhibits high temperature sensitivity (high negative ?H') in the presence of Cl(-) ions, supporting the inverse relationship between the number of Cl(-)-binding sites and temperature sensitivity, and extending it to ectothermic vertebrates. The radically reduced chloride binding in Telmatobius Hb permits assessment of the enthalpy of ATP binding [(?H' ? -62 kJ (mol ATP)(-1) at pH 7.0]-which contrasts sharply with previously reported increases in temperature sensitivity by ATP in toad (Bufo bufo) Hb. The high temperature sensitivity associated with decreased chloride binding and low phosphate sensitivity of Telmatobius Hb likely promotes cutaneous O2 uptake in cold, high-altitude ponds and streams.

  6. 75 FR 37358 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Arroyo Toad

    Science.gov (United States)

    2010-06-29

    ...the exclusion will not result in the extinction of the species. Changes to Proposed...critical habitat will result in the extinction of the species. In making that determination...venue for SERE (Survival, Evasion, Resistance, and Escape) training on the...

  7. 76 FR 7245 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Arroyo Toad

    Science.gov (United States)

    2011-02-09

    ...change on a local or regional economy. The FEA continues to rely...be quantified by researching tourism and visitation, and that mentioning...100 million or more on the economy or adversely affect an economic...near-perennial flow that contributes to the persistence of...

  8. Evidence for the introduction of lethal Chytridiomycosis affecting wild betic midwife toads (Alytes dickhilleni).

    Science.gov (United States)

    Bosch, Jaime; García-Alonso, David; Fernández-Beaskoetxea, Saioa; Fisher, Matthew C; Garner, Trenton W J

    2013-03-01

    Batrachochytrium dendrobatidis is an unpredictable pathogen for European amphibian species, and existing field surveillance studies likely underestimate the scope of its distribution and effects. Mass mortality episodes recorded in Europe indicate that investigations of unstudied species should focus on members of the frog family Alytidae. Here, we report the combined results of a field survey and laboratory observations of field collected Alytes dickhilleni. Our data support the hypothesis that B. dendrobatidis has recently emerged in at least two disjunct locations in the species range and populations across much of the species range lack evidence of infection pathogen. Tadpoles taken into the laboratory from sites with infection experienced 70% mortality, unlike those taken into the laboratory from uninfected sites, and both infection and strength of infection was associated with mortality in animals collected from infected locations. Several conservation interventions are underway in response to our study, including the establishment of a captive assurance colony, a public awareness campaign, and experimental tests of disease mitigation schemes. PMID:23494771

  9. A new species of arboreal toad (Anura : Bufonidae : Chaunus) from Madidi National Park, Bolivia

    Science.gov (United States)

    Padial, J.M.; Reichle, S.; McDiarmid, R.; De la Riva, I.

    2006-01-01

    A new arboreal species of the Chaunus veraguensis group is described for the humid montane forest of Madidi National Park, in northern Bolivia. The new species differs from other species in the group by the combination small size, long and slender extremities, webbed hands, conspicuous tympanic membrane, well developed parotoid glands, absence of large glands on dorsum and extremities, nuptial excrescences of males composed of pungent spines on dorsal surface of thumb, greenish-brown coloration on dorsum with red warts in life, and green iris. It is only known from two nearby localities in the Serran Eslabon, Department La Paz. An operational key for species in the C. veraguensis group is provided.

  10. Transformations of Aortic Arches During Metamorphosis of the Spade-Foot Toad, Pelobates fuscus.

    Czech Academy of Sciences Publication Activity Database

    Majorová, H.; Ro?ek, Zbyn?k

    2004-01-01

    Ro?. 260, ?. 3 (2004), s. 309. ISSN 0362-2525. [International Congress of Vertebrate Morphology /7./. 27.07.2004-01.08.2004, Boca Raton] Keywords : Anura * Circulatory System * Metamorphosis Subject RIV: EA - Cell Biology

  11. A curious case of herbivory in the common toad Rhinella arenarum during hibernation in captivity conditions

    Directory of Open Access Journals (Sweden)

    Pozzi, Andrea Gabriela

    2012-12-01

    Full Text Available El objetivo de la presente nota es documentar un comportamiento curioso ocurrido con un grupo de animales adultos de Rhinella arenarum que fueron mantenidos en condiciones de hibernación artificial en el laboratorio durante abril-julio del 2012.

  12. Isolation and characterization of microsatellite loci for the endangered Midwife Betic toad Alytes dickhilleni (Discoglossidae)

    OpenAIRE

    Albert, Eva M.; Arroyo, Juan M.; Godoy, Jose? A.

    2011-01-01

    We have developed eleven polymorphic micro- satellite loci for the amphibian Alytes dickhilleni using an enriched-library approach. We detected 98 alleles in 50 individuals genotyped (mean number of alleles per locus was 8.91) in two different populations in South East Spain. Expected heterozygosities ranged from 0.324 to 0.891 in one population (Arroyo Guadahornillos) and 0.424–0.909 in the other population (Cueva Paria). The levels of poly- morphism of the developed markers render them re...

  13. Interactions of an insecticide, herbicide, and natural stressors in amphibian community mesocosms

    Science.gov (United States)

    Boone, M.D.; James, S.M.

    2003-01-01

    Amphibians developing in wetlands embedded within or near agricultural lands may frequently encounter chemical mixtures. The objectives of our study were to determine the effects that post-application concentrations of an insecticide (carbaryl) and an herbicide (atrazine) have on body mass, development, and survival of two anuran species (southern leopard frog, Rana sphenocephala; American toad, Bufo americanus) and two caudate species (spotted salamander, Ambystoma maculatum; small-mouthed salamander, A. texanum) reared in outdoor cattle tank mesocosms. In one experiment, we manipulated tadpole density (low or high), carbaryl exposure (0, 3.5, 7.0 mg/L), and atrazine exposure (0 or 200 ??g/L) to test for effects on development, mass, and survival of larvae. In a second experiment, we manipulated pond hydroperiod (constant or drying), carbaryl exposure (0 or 5 mg/L), and atrazine exposure (0 or 200 ??g/L) to test for effects on mass, time, and survival to metamorphosis. Salamanders were virtually eliminated in carbaryl treatments, indicating that at realistic levels, this insecticide could cause population declines for salamanders in contaminated habitats. Carbaryl also had negative effects on toad survival. Exposure to atrazine had negative effects on body size, development, and time to metamorphosis in anuran species, which were associated with reduced chlorophyll levels. Both chemicals interacted significantly with density or hydroperiod, indicating that the environmental conditions could influence the impact of a contaminant. A significant atrazine-by-carbaryl interaction resulted in smaller and less developed spotted salamander larvae than in control ponds. Atrazine exposure, however, appeared to moderate negative effects of carbaryl for spotted salamanders. Our research suggests that important changes in the community's food web result from chemical exposure, which influence the susceptibility of amphibian species to contaminants.

  14. Expression of G proteins in the olfactory receptor neurons of the newt Cynops pyrrhogaster: their unique projection into the olfactory bulbs.

    Science.gov (United States)

    Nakada, Tomoaki; Hagino-Yamagishi, Kimiko; Nakanishi, Koki; Yokosuka, Makoto; Saito, Toru R; Toyoda, Fumiyo; Hasunuma, Itaru; Nakakura, Takashi; Kikuyama, Sakae

    2014-10-15

    We analyzed the expression of G protein ? subunits and the axonal projection into the brain in the olfactory system of the semiaquatic newt Cynops pyrrhogaster by immunostaining with antibodies against G?olf and G?o , by in situ hybridization using probes for G?olf , G?o , and G?i2 , and by neuronal tracing with DiI and DiA. The main olfactory epithelium (OE) consists of two parts, the ventral OE and dorsal OE. In the ventral OE, the G?olf - and G?o -expressing neurons are located in the apical and basal zone of the OE, respectively. This zonal expression was similar to that of the OE in the middle cavity of the fully aquatic toad Xenopus laevis. However, the G?olf - and G?o -expressing neurons in the newt ventral OE project their axons toward the main olfactory bulb (MOB) and the accessory olfactory bulb (AOB), respectively, whereas in Xenopus, the axons of both neurons project solely toward the MOB. In the dorsal OE of the newt, as in the principal cavity of Xenopus, the majority of the neurons express G?olf and extend their axons into the MOB. In the vomeronasal organ (VNO), the neurons mostly express G?o . These neurons and quite a few G?olf -expressing neurons project their axons toward the AOB. This feature is similar to that in the terrestrial toad Bufo japonicus and is different from that in Xenopus, in which VNO neurons express solely G?o , although their axons invariably project toward the AOB. We discuss the findings in the light of diversification and evolution of the vertebrate olfactory system. PMID:24771457

  15. Notes on the Vertebrates of northern Pará, Brazil: a forgotten part of the Guianan Region, I. Herpetofauna

    Directory of Open Access Journals (Sweden)

    Teresa Cristina Sauer Avila-Pires

    2010-04-01

    Full Text Available We discuss the herpetological results of seven expeditions to the Guianan part of Pará, which resulted in a total of 80 species of amphibians (77 frogs and three caecilians and 95 species of reptiles (36 species of lizards, three species of amphisbaenians, 49 species of snakes, five species of chelonians and two species of caiman. We report six species new to science (three frogs, one caecilian, one lizard, one amphisbaenian, six new records for Brazil (five frogs, one caecilian and 23 new records for Pará (13 frogs, four lizards, six snakes. For each of the new records we provide comments. Special comment is made about a large population of the toad Atelopus hoogmoedi that seems to be doing well and does not show any signs of population decline as many species of Atelopus at higher elevations do. We provide a complete list of species collected per locality containing data on endemicity, habitat, reproduction and food. For each of the seven collecting sites we provide data on richness and abundance of species. The sites are compared regarding their speciescomposition, even though we can not say how much of the differences are due to specific habitats or geographic variation, seasonal variation or sampling deficiency. We synonymised the Bufonid Rhinella martyi with Bufo margaritifer and selected a lectotype for Rana margaritifera in order to resolve the problems about this name.

  16. Hindlimb deformities (ectromelia, ectrodactyly) in free-living anurans from agricultural habitats.

    Science.gov (United States)

    Ouellet, M; Bonin, J; Rodrigue, J; DesGranges, J L; Lair, S

    1997-01-01

    High prevalences of hindlimb deformities were recorded in wild-caught green frogs (Rana clamitans), northern leopard frogs (Rana pipiens), American toads, (Bufo americanus), and bullfrogs (Rana catesbeiana) from agricultural sites exposed to pesticide runoff in the St. Lawrence River Valley of Québec, Canada, between July and September 1992 and 1993. Of 853 metamorphosing anurans examined in 14 farmland habitats, 106 (12%; range 0 to 69%) had severe degrees of ectromelia and ectrodactyly, compared to only two (0.7%; range 0 to 7.7%) of 271 in 12 control sites. However, the variation in the proportion of deformities among sites was too large to conclude that there was a significant difference between control and pesticide-exposed habitats. Clinical signs varied and were characterized by segmental hypoplasia or agenesis of affected limbs. Conspicuous abnormalities interfered with swimming and hopping, and likely constituted a survival handicap. Because of circumstances and the frequency of these malformations in nine distinct habitats, and in three different species from one of our study sites, we propose a teratogenic action of exogenous factors. Despite the fact that many biotic and abiotic agents are potentially harmful to limb development, agricultural contaminants were suspected as primary aggressors. Thus, clinical examination and frequency of deformities in anurans might be an economical screening tool to assess ecosystem health and the presence of environmental contaminants. PMID:9027696

  17. Synergistic impacts of malathion and predatory stress on six species of North American tadpoles.

    Science.gov (United States)

    Relyea, Rick A

    2004-04-01

    The decline of many amphibian populations is associated with pesticides, but for most pesticides we know little about their toxicity to amphibians. Malathion is a classic example; it is sprayed over aquatic habitats to control mosquitoes that carry malaria and the West Nile virus, yet we know little about its effect on amphibians. I examined the survival of six species of tadpoles (wood frogs, Rana sylvatica; leopard frogs, R. pipiens; green frogs, R. clamitans; bullfrogs, R. catesbeiana; American toads, Bufo americanus; and gray tree frogs, Hyla versicolor) for 16 d in the presence or absence of predatory stress and six concentrations of malathion. Malathion was moderately toxic to all species of tadpoles (median lethal concentration [LC50] values, the concentration estimated to kill 50% of a test population, ranged from 1.25-5.9 mg/L). These values are within the range of values reported for the few amphibians that have been tested (0.2-42 mg/L). In one of the six species, malathion became twice as lethal when combined with predatory stress. Similar synergistic interactions have been found with the insecticide carbaryl, suggesting that the synergy may occur in many carbamate and organophosphate insecticides. While malathion has the potential to kill amphibians and its presence is correlated with habitats containing declining populations, its actual role in amphibian declines is uncertain given the relatively low concentration in aquatic habitats. PMID:15095908

  18. Hemoparasites of the genus Trypanosoma (Kinetoplastida: Trypanosomatidae) and hemogregarines in Anurans of the São Paulo and Mato Grosso do Sul States - Brazil.

    Science.gov (United States)

    Leal, Denise D M; O'dwyer, Lucia H; Ribeiro, Vitor C; Silva, Reinaldo J; Ferreira, Vanda L; Rodrigues, Rozangela B

    2009-06-01

    Wild animals are exposed to numerous pathogens, including hemoparasites. The Trypanosoma and hemogregarinegroup are frequently reported as parasites in anurans (frogs, tree frogs and toads). The identification of these hemoparasites is usually made through stage observation of their morphology in the peripheral blood of the host. There areno studies, however, based on the biological cycle of these hemoparasites. The objective of the present study was toevaluate the presence of hemogregarines and Trypanosoma spp. in anurans captured in the States of São Paulo andMato Grosso do Sul- Brazil and to perform the morphological and morphometric characterization of these hemoparasites. The species of anurans examined were: Dendropsophus nanus, D. minutus, Leptodactylus chaquensis L. podicipinus, L. labyrinthicus, L. fuscus, Bufo granulosus, B. schneideri, Phyllomedusa hypocondrialis, Trachicephalus venulosus, Scinax fuscovarius and Hypsiboas albopunctatus. Of the total of 40 animals studied, four (10%)were positive for hemogregarines and eight (20%) were positive for Trypanosoma spp. Hemogregarine gamontsshowed variable morphology and, in addition to intraerythrocytic forms, extraerythrocytic forms were also observed.Extremely different forms of Trypanosoma were observed, as described in the literature, with the broad and oval forms being the most common. PMID:19488624

  19. Response of amphibian liver to external gamma irradiation

    International Nuclear Information System (INIS)

    Adults toads (Bufo andersonii) were exposed to four doses (i.e. 2.25, 4.50, 6.75 and 9.00 Gy) of gamma radiation from a 60Co source. Five animals were sacrificed at each post-irradiation interval of 1, 2, 3, 7 and 14 days. The liver was fixed in Bouin's fluid and after processing in a routine way, it was examined histologically. The radiation effects were found dose-dependent. The pathological changes appeared on day 3 in the 2.25 Gy group and on day 1 in all the other dose groups. The radiolesions increased gradually in severity up to day 3 in the latter groups followed by onset of recovery on the 7th day. The liver appeared normal in structure on the last interval studied (14 days) in 2.25, 4.50 and 6.75 Gy groups but a few lesions still persisted in the 9.0 Gy group. On day 14 lymphoid structures exhibiting lymphopoiesis were also observed in the 9.0 Gy group. (author)

  20. A Survey on the Faunal Diversity of Savar Upazila, Dhaka, Bangladesh

    Directory of Open Access Journals (Sweden)

    Md. Eftekhar Hossain

    2008-01-01

    Full Text Available A survey was conducted during January to December 2006 to assess the status of faunal diversity of Savar Upazila, Dhaka, Bangladesh. A total of 30 species of birds, 24 species of winter birds, 7 species of reptiles, 3 species of amphibians, 15 species of mammalians and 32 species of fishes were recorded. Relative abundance of those species were determined. Of the birds, House Sparrow (Passer domesticus was abundant while Blyth's Kingfisher (Alcedo hercules, Rock Eagle Owl (Bubo bengalensis, Hooded Pitta (Pitta sordida, Black-headed Oriole (Oriolus xanthornus, White-winged Duck (Cairina seululala and Duck (Anser indicus were rare. The relative abundance of winter bird could not be assessed because of their migratory habit. Striped keelback (Amphiesma stolata and Common Smooth Water Snake (Enhydris enhydris were very common while Black pond turtle (Geoclyms hamiltonii and Pond tortoise (Melanochelys trijuga were recorded as endangered. Common Toad (Bufo melanostictus were abundant but Bull Frog (Rana tigrina was rare. Asiatic Wild Dog (Cuon alpinus and House Mouse (Mus musculus were abundant while Common Otter, Large Indian Civet, Irrawaddy River Dolphin, Indian Hare were rare. Carpu, Silver carp, Tilapia, Nilotica were abundant while, Freshwater Garfish, One stripe spinyeel and Grey Featherback were rare. Landfilling, deforestation, poaching, industrial effluents and current jal were identified as major threats to the faunal diversity of Savar area.

  1. The effects of dexamethasone (DXM) and vitamin A on the growth and metamorphosis of gamma irradiated, thyroxine induced Bufo melanostictus tadpoles

    International Nuclear Information System (INIS)

    This study deals with the effects of vitamin A and dexamethasone (DXM) on the metamorphosis of irradiated tadpoles. Results indicate that hypervitaminosis A depresses the metamorphosing action of thyroxine for several days. On the contrary, dexamethasone accelerates the action of exogenous thyroxine on tadpoles. Thus present data suggest that DXM supresses STH synthesis and promotes TSH secretion. Moreover, muscle appears to be its target tissue and DXM seems to promote the proteolytic digestion of the larval tail. (author)

  2. Responses on toad tadpoles to ammonium nitrate fertilizer and predatory stress: differences between populations on a local scale

    OpenAIRE

    Orti?z-santaliestra, Manuel E.; Ferna?ndez-bene?itez, Mari?a Jose?; Lizana, Miguel; Marco, Adolfo

    2011-01-01

    — Agriculture-related pollution is among the major causes of global amphibian population declines. The multiple stressors to which amphibians are exposed in the ?eld, such as predation pressure, can make agrochemicals far more deadly than when they act in isolation. Even within a small area, diffuse agricultural pollution does not affect all aquatic environments equally, which could account for local differences in amphibian sensitivity to agrochemicals. We examined the combined effects o...

  3. Are hedgehogs like pigs, or tortoises like toads? : language-specific effects of compound structure on conceptualisation

    OpenAIRE

    Wiese, Heike

    2010-01-01

    How far can language-specific structures influence conceptualisation? After a period of time where the discussion of any ‘Whorfian’ effects tended to be considered of little scientific merit, the recent decade has seen a renewed interest in this question. In particular, studies have aimed to tease apart ‘thinking for speaking’ from general cognition (cf. Slobin 1996, Stutterheim & Nüse 2002) and have shown that language-specific differences can often be observed in verbalisation as w...

  4. Quantitative study of Trichodina heterodentata (Ciliophora: Mobilia infrapopulations infesting tadpoles of a Brazilian endemic toad Rhinella pombali (Anura: Bufonidae

    Directory of Open Access Journals (Sweden)

    Noemi M. Fernandes

    2011-12-01

    Full Text Available In this work we investigated the quantitative aspects of the relationship between Rhinella pombali (Baldissera, Caramaschi & Haddad, 2004 tadpoles and their trichodinid ectoparasites. Specimens were collected from a small stream located at an agricultural area between rainforest fragments in southeastern Brazil. A total of 80 tadpoles were investigated. Trichodina heterodentata Duncan, 1977 was the only trichodinid ciliate species recovered. All tadpoles were naturally infested by T. heterodentata with a mean intensity of 695.14 ± 33.33 trichodinid ciliates per tadpole. A positive correlation was observed between the intensity of the infestation and tadpole weight. Intensity of infestation did not significantly influence mean trichodinid diameter in the populations studied. This is the first study investigating density-dependent effects in interspecific interactions between trichodinids and anurans.

  5. Nuclear and mitochondrial phylogeography of the European fire-bellied toads Bombina bombina and Bombina variegata supports their independent histories.

    Czech Academy of Sciences Publication Activity Database

    Fijarczyk, A.; Nadachowska, K.; Hofman, S.; Litvinchuk, S.N.; Babik, W.; Stuglik, M.; Gollmann, G.; Choleva, Lukáš; Cogalniceanu, D.; Vukov, T.; Dzukic, G.; Szymura, J. M.

    2011-01-01

    Ro?. 20, ?. 16 (2011), s. 3381-3398. ISSN 0962-1083 Institutional research plan: CEZ:AV0Z50450515 Keywords : Bombina * isolation with migration * nuclear and mitochondrial markers Subject RIV: EH - Ecology , Behaviour Impact factor: 5.522, year: 2011

  6. Biomarker Analysis of American Toad (Anaxyrus Americanus) and Grey Tree Frog (Hyla Versicolor) Tadpoles Following Exposure to Atrazine

    Science.gov (United States)

    To better understand the mode of action of atrazine in amphibians, we utilized mass spectrometry-based metabolomics to investigate the biochemical changes in two species of larval amphibians exposed to atrazine. Our objectives were to 1) Use changes in endogenous metabolites to f...

  7. Tribulations of a prostate cancer trial - lessons learned from TOAD, a cancer council Victoria and Transtasman Radiation Oncology Group Trial

    International Nuclear Information System (INIS)

    Full text: From 2004-2009 a total of 226 out of a target of 750 prostate cancer patients have been randomised into the Timing of Androgen Deprivation trial between immediate and delayed androgen deprivation. A screening log was kept by participating centres for the first 928 patients, which documented the reasons for non-entry into the trial; 42.7% of screened patients were ineligible and a further 33.0% were not entered for other reasons. Fewer than 10% of patients cited not wanting to be part of a clinical trial as a reason for non-entry. Strategies to improve recruitment included broadening the eligibility criteria, encouraging international collaboration, the use and support of research nurses in the private health care environment, and the use of phone follow-up. Recruitment will be completed at the number originally intended to inform the interim analysis designed to test the validity of the statistical assumptions, and a combined survival analysis with the Canadian study is planned.

  8. Tracking Amendments to Legislation and Other Political Texts with a Novel Minimum-Edit-Distance Algorithm: DocuToads.

    DEFF Research Database (Denmark)

    Hermansson, Henrik Alf Jonas; Cross, James

    2015-01-01

    Political scientists often nd themselves tracking amendments to political texts. As different actors weigh in, texts change as they are drafted and redrafted, reflecting political preferences and power. This study provides a novel solution to the problem of detecting amendments to political text based upon minimum edit distances. We demonstrate the usefulness of two language-insensitive, transparent, and efficient minimum-edit-distance algorithms suited for the task. These algorithms are capable of providing an account of the types (insertions, deletions, substitutions, and transpositions) and substantive amount of amendments made between version of texts. To illustrate the usefulness and eciency of the approach we replicate two existing studies from the field of legislative studies. Our results demonstrate that minimum edit distance methods can produce superior measures of text amendments to hand-coded efforts in a fraction of the time and resource costs.

  9. Mechanisms of adreno- and cholinoreceptors in isolated pulmonary and systemic vasculature of the cane toad (Rhinella marina)

    DEFF Research Database (Denmark)

    Pedersen, Pil Birkefeldt MØller; Wang, Tobias

    While the overall autonomic regulation of the heart and vasculature of anurans has been studied in some detail, little is known about the role of the adreno- and cholinoreceptors in smooth muscle when looking at resistance in the pulmonary and systemic vessels. Vascular smooth muscle is the primary site of regulation of resistance and therefore holds the capacity to control blood flow and pressure. This vascular control allows amphibians to regulate their shunt, i.e. partially bypassing either the pulmonary or systemic circuit. Shunting in amphibians has been studied due to their multiple respiratory modalities and their ontogeny including fundamental morphological changes during metamorphosis. Here we use wire myography to evaluate how the vascular tone of isolated blood vessels from the pulmocutaneous, pulmonary, cutaneous and systemic segments respond to sympathetic and parasympathetic stimulation. Hence, myography on vessels ranging from 0.2 to 2.0 mm allow for the investigation of isometric response to agonists and antagonists of smooth muscle with no autonomic tone. This provides the possibility of mapping the function of adreno- and cholinoreceptor in vascular regulation in anurans.

  10. Quantitative study of Trichodina heterodentata (Ciliophora: Mobilia) infrapopulations infesting tadpoles of a Brazilian endemic toad Rhinella pombali (Anura: Bufonidae)

    Scientific Electronic Library Online (English)

    Noemi M., Fernandes; Bianca, Sartini; Roberto J. P., Dias; Marta, D' Agosto.

    2011-12-01

    Full Text Available In this work we investigated the quantitative aspects of the relationship between Rhinella pombali (Baldissera, Caramaschi & Haddad, 2004) tadpoles and their trichodinid ectoparasites. Specimens were collected from a small stream located at an agricultural area between rainforest fragments in southe [...] astern Brazil. A total of 80 tadpoles were investigated. Trichodina heterodentata Duncan, 1977 was the only trichodinid ciliate species recovered. All tadpoles were naturally infested by T. heterodentata with a mean intensity of 695.14 ± 33.33 trichodinid ciliates per tadpole. A positive correlation was observed between the intensity of the infestation and tadpole weight. Intensity of infestation did not significantly influence mean trichodinid diameter in the populations studied. This is the first study investigating density-dependent effects in interspecific interactions between trichodinids and anurans.

  11. Soluble beta-galactosyl-binding lectin (galectin) from toad ovary: crystallographic studies of two protein-sugar complexes.

    Science.gov (United States)

    Bianchet, M A; Ahmed, H; Vasta, G R; Amzel, L M

    2000-08-15

    Galectin-1, S-type beta-galactosyl-binding lectins present in vertebrate and invertebrate species, are dimeric proteins that participate in cellular adhesion, activation, growth regulation, and apoptosis. Two high-resolution crystal structures of B. arenarum galectin-1 in complex with two related carbohydrates, LacNAc and TDG, show that the topologically equivalent hydroxyl groups in the two disaccharides exhibit identical patterns of interaction with the protein. Groups that are not equivalent between the two sugars present in the second moiety of the disaccharide, interact differently with the protein, but use the same number and quality of interactions. The structures show additional protein-carbohydrate interactions not present in previously reported lectin-lactose complexes. These contacts provide an explanation for the enhanced affinity of galectin-1 for TDG and LacNAc relative to lactose. Galectins are in dimer-monomer equilibrium at physiological protein concentrations, suggesting that this equilibrium may be involved in organ-specific regulation of activity. Comparison of B. arenarum with other galectin-1 structures shows that among different galectins there are significant changes in accessible surface area buried upon dimer formation, providing a rationale for the variations observed in the free-energies of dimerization. The structure of the B. arenarum galectin-1 has a large cleft with a strong negative potential that connects the two binding sites at the surface of the protein. Such a striking characteristic suggests that this cleft is probably involved in interactions of the galectin with other intra or extra-cellular proteins. Proteins 2000;40:378-388. PMID:10861929

  12. A new species of Paracapillaria (Nematoda: Capillariidae) from the intestine of the toad Duttaphrynus melanostictus (Anura) from the Malayan Peninsula.

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Modrý, David; Jirk?, Miloslav

    2007-01-01

    Ro?. 93, ?. 4 (2007), s. 907-909. ISSN 0022-3395 R&D Projects: GA ?R(CZ) GA524/06/0170; GA MŠk LC522 Institutional research plan: CEZ:AV0Z60220518 Keywords : Paracapillaria * Duttaphrynus * Malayan Peninsula Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.129, year: 2007

  13. Contributions to knowledge regarding the geographical distribution of the herpetofauna of Dobrudja, Romania

    OpenAIRE

    Bogdan, Horia V.; Strugariu, Alexandru; Sas, Istvan; Cicort-lucaciu, Alfred-s?tefan; Ghira, Ioan; Covaciu-marcov, Severus-daniel

    2006-01-01

    In Dobrudja we encountered 10 species of amphibians (Triturus dobrogicus, Bombina bombina, Hyla arborea, Pelobates fuscus, Pelobates syriacus, Bufo bufo, Bufo viridis, Rana dalmatina, Rana ridibunda, Rana lessonae), 16 species of reptiles (Emys orbicularis, Testudo graeca, Ablepharus kitaibelli, Lacerta agilis, Lacerta viridis, Lacerta trilineata, Podarcis taurica, Podarcis muralis, Eremias arguta, Coronella austriaca, Zamensis longissimus, Elaphe quatuorlineata, Dolichophis caspius, Natrix n...

  14. 77 FR 21920 - Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To List the Eastern...

    Science.gov (United States)

    2012-04-12

    ...boreal toad adults' having toxic skin secretions, boreal toads have...stated above, Bd attacks the skin of boreal toads and may cause...ectotherms (require heat from the sun or outside sources to warm selves...an enzyme that repairs UV-B damage, is lower in boreal toads...

  15. Hemoparasites of the genus Trypanosoma (Kinetoplastida: Trypanosomatidae and hemogregarines in Anurans of the São Paulo and Mato Grosso do Sul States - Brazil

    Directory of Open Access Journals (Sweden)

    Denise D.M. Leal

    2009-06-01

    Full Text Available Wild animals are exposed to numerous pathogens, including hemoparasites. The Trypanosoma and hemogregarinegroup are frequently reported as parasites in anurans (frogs, tree frogs and toads. The identification of these hemoparasites is usually made through stage observation of their morphology in the peripheral blood of the host. There areno studies, however, based on the biological cycle of these hemoparasites. The objective of the present study was toevaluate the presence of hemogregarines and Trypanosoma spp. in anurans captured in the States of São Paulo andMato Grosso do Sul- Brazil and to perform the morphological and morphometric characterization of these hemoparasites. The species of anurans examined were: Dendropsophus nanus, D. minutus, Leptodactylus chaquensis L. podicipinus, L. labyrinthicus, L. fuscus, Bufo granulosus, B. schneideri, Phyllomedusa hypocondrialis, Trachicephalus venulosus, Scinax fuscovarius and Hypsiboas albopunctatus. Of the total of 40 animals studied, four (10%were positive for hemogregarines and eight (20% were positive for Trypanosoma spp. Hemogregarine gamontsshowed variable morphology and, in addition to intraerythrocytic forms, extraerythrocytic forms were also observed.Extremely different forms of Trypanosoma were observed, as described in the literature, with the broad and oval forms being the most common.Os animais silvestres estão expostos a inúmeros patógenos,dentre eles estão os hemoparasitas. Podem-se destacar espécies do gênero Trypanosoma e do grupo das hemogregarinas,que ocorrem com freqüência parasitando anuros (rãs, pererecas e sapos. Normalmente, a descrição destes hemoparasitas é feita através da morfologia dos estágios observados nosangue periférico do hospedeiro e as pesquisas sobre o ciclobiológico desses hemoparasitas são escassas. Os objetivos dopresente estudo foram avaliar a presença de hemogregarinas eTrypanosoma spp. em anuros capturados nos Estados de São Paulo e Mato Grosso do Sul e fazer a caracterização morfológica e morfométrica dos seus hemoparasitas. As espécies deanuros examinadas foram: Dendropsophus nanus, D. minutus, Leptodactylus chaquensis, L. podicipinus, L. labyrinthicus, L. fuscus, Bufo granulosus, B. schneideri, Phyllomedusahypocondrialis, Trachicephalus venulosus, Scinax fuscovarius e Hypsiboas albopunctatus. Dos 40 animais estudados, foramencontrados quatro (10% positivos para hemogregarinas e oito(20% positivos para Trypanosoma spp. Foram observadosgamontes de hemogregarinas com morfologia variável e, alémdas formas intraeritrocíticas, também foram observados gamontes fora das hemácias. As formas de Trypanosoma encontradas eram muito polimórficas, conforme é descrito na literatura, sendo na sua maioria, larga e oval.

  16. Hemoparasites of the genus Trypanosoma (Kinetoplastida: Trypanosomatidae) and hemogregarines in Anurans of the São Paulo and Mato Grosso do Sul States - Brazil

    Scientific Electronic Library Online (English)

    Denise D.M., Leal; Lucia H., O' dwyer; Vitor C., Ribeiro; Reinaldo J., Silva; Vanda L., Ferreira; Rozangela B., Rodrigues.

    2009-06-01

    Full Text Available Os animais silvestres estão expostos a inúmeros patógenos,dentre eles estão os hemoparasitas. Podem-se destacar espécies do gênero Trypanosoma e do grupo das hemogregarinas,que ocorrem com freqüência parasitando anuros (rãs, pererecas e sapos). Normalmente, a descrição destes hemoparasitas é feita a [...] través da morfologia dos estágios observados nosangue periférico do hospedeiro e as pesquisas sobre o ciclobiológico desses hemoparasitas são escassas. Os objetivos dopresente estudo foram avaliar a presença de hemogregarinas eTrypanosoma spp. em anuros capturados nos Estados de São Paulo e Mato Grosso do Sul e fazer a caracterização morfológica e morfométrica dos seus hemoparasitas. As espécies deanuros examinadas foram: Dendropsophus nanus, D. minutus, Leptodactylus chaquensis, L. podicipinus, L. labyrinthicus, L. fuscus, Bufo granulosus, B. schneideri, Phyllomedusahypocondrialis, Trachicephalus venulosus, Scinax fuscovarius e Hypsiboas albopunctatus. Dos 40 animais estudados, foramencontrados quatro (10%) positivos para hemogregarinas e oito(20%) positivos para Trypanosoma spp. Foram observadosgamontes de hemogregarinas com morfologia variável e, alémdas formas intraeritrocíticas, também foram observados gamontes fora das hemácias. As formas de Trypanosoma encontradas eram muito polimórficas, conforme é descrito na literatura, sendo na sua maioria, larga e oval. Abstract in english Wild animals are exposed to numerous pathogens, including hemoparasites. The Trypanosoma and hemogregarinegroup are frequently reported as parasites in anurans (frogs, tree frogs and toads). The identification of these hemoparasites is usually made through stage observation of their morphology in th [...] e peripheral blood of the host. There areno studies, however, based on the biological cycle of these hemoparasites. The objective of the present study was toevaluate the presence of hemogregarines and Trypanosoma spp. in anurans captured in the States of São Paulo andMato Grosso do Sul- Brazil and to perform the morphological and morphometric characterization of these hemoparasites. The species of anurans examined were: Dendropsophus nanus, D. minutus, Leptodactylus chaquensis L. podicipinus, L. labyrinthicus, L. fuscus, Bufo granulosus, B. schneideri, Phyllomedusa hypocondrialis, Trachicephalus venulosus, Scinax fuscovarius and Hypsiboas albopunctatus. Of the total of 40 animals studied, four (10%)were positive for hemogregarines and eight (20%) were positive for Trypanosoma spp. Hemogregarine gamontsshowed variable morphology and, in addition to intraerythrocytic forms, extraerythrocytic forms were also observed.Extremely different forms of Trypanosoma were observed, as described in the literature, with the broad and oval forms being the most common.

  17. Study on the radiation dose assessment of non-human species near a site in the south of China

    International Nuclear Information System (INIS)

    In the external environment of a site located in the South China, the Chinese toad (Bufo gargarizans), dry duck and teal, and pine tree (Pinus massoniana Lamb) are studied as reference organisms. Through investigation, the parameters of biological characteristics of the species are provided. The radionuclide concentration ratio CR (defined as the ratio of activity concentration in biota whole body (Bq · kg-1 fresh weight) and activity concentration of soil (Bq · kg-1 dry weight) or activity concentration of filtered water(Bq · L-1)) are provided by collecting biological and environmental media samples and 90Sr and 137Cs activity analysis. By the ERICA tool of EC, the dose rates of the species for 90Sr and 137Cs are estimated. The results show that the dose rates of 90Sr and 137Cs for Chinese toad are 1.69 E 03 ?Gy · h-1 and 6.96 E-03 ?Gy · h-1 respectively, the total dose rate is 8.65 E-03 ?Gy · h-1. The dose rates of 90Sr and 137Cs for teal are 1.56 E-04 ?Gy · h-1 and 2.68 E-04E?Gy · h-1, the total dose rate is 4.24E-04 ?Gy · h-1. The dose rates of 90Sr and 137Cs for dry duck are 2.04E-04 ?Gy · h-1 and 2.29 E-04E?Gy · h-1, the total dose rate is 4.33E-04 ?Gy · h-1. The total dose rates of the reference animals are well below the IAEA recommended dose limit for terrestrial animals (40 ?Gy · h-1). The order of dose rates of 90Sr and 137Cs for pine, from high to low are: pine needles > pine branches > pine trunk. The total dose rate of pine needles is 1.38E-03 ?Gy · h-1, which is well below the IAEA recommended dose limit for terrestrial plants (400 ?Gy · h-1). (authors)

  18. Diet quality influences isotopic discrimination among amino acids in an aquatic vertebrate.

    Science.gov (United States)

    Chikaraishi, Yoshito; Steffan, Shawn A; Takano, Yoshinori; Ohkouchi, Naohiko

    2015-05-01

    Stable nitrogen isotopic composition of amino acids (? (15)NAA) has recently been employed as a powerful tool in ecological food web studies, particularly for estimating the trophic position (TP) of animal species in food webs. However, the validity of these estimates depends on the consistency of the trophic discrimination factor (TDF; - ?? (15)NAA at each shift of trophic level) among a suite of amino acids within the tissues of consumer species. In this study, we determined the TDF values of amino acids in tadpoles (the Japanese toad, Bufo japonicus) reared exclusively on one of three diets that differed in nutritional quality. The diets were commercial fish-food pellets (plant and animal biomass), bloodworms (animal biomass), and boiled white rice (plant carbohydrate), representing a balanced, protein-rich, and protein-poor diet, respectively. The TDF values of two "source amino acids" (Src-AAs), methionine and phenylalanine, were close to zero (0.3-0.5‰) among the three diets, typifying the values reported in the literature (?0.5‰ and ?0.4‰, respectively). However, TDF values of "trophic amino acids" (Tr-AAs) including alanine, valine, leucine, isoleucine, and glutamic acid varied by diet: for example, the glutamic acid TDF was similar to the standard value (?8.0‰) when tadpoles were fed either the commercial pellets (8.0‰) or bloodworms (7.9‰), but when they were fed boiled rice, the TDF was significantly reduced (0.6‰). These results suggest that a profound lack of dietary protein may alter the TDF values of glutamic acid (and other Tr-AAs and glycine) within consumer species, but not the two Src-AAs (i.e., methionine and phenylalanine). Knowledge of how a nutritionally poor diet can influence the TDF of Tr- and Src-AAs will allow amino acid isotopic analyses to better estimate TP among free-roaming animals. PMID:26045955

  19. Preliminary data regarding the distribution and status of the herpetofauna in Ia?i County (Romania)

    OpenAIRE

    Strugariu, Alexandru; Zamfirescu, S?tefan R.; Nicoara?, Andreea; Gherghel, Iulian; Sas, Istvan; Pus?cas?u, Cristina M.; Bugeac, Teodor

    2008-01-01

    This paper presents the results of a study conducted in Ia?i County, Romania, an area for which data regarding the distribution of the herpetofauna has previously remained incomplete. Thirteen species of amphibians (Salamandra salamandra, Lissotriton vulgaris, Triturus cristatus, Pelobates fuscus, Hyla arborea, Bombina bombina, Bombina variegata, Bufo bufo, Bufo viridis, Pelophylax ridibundus, Pelophylax lessonae, Rana dalmatina and Rana temporaria), nine reptile species (Emys orbicularis, ...

  20. The herpethofauna from the Teuz River hydrographic basin (Arad County, Romania)

    OpenAIRE

    Bogdan, H.; Kiss, A.; Sas, I.; Covaciu-marcov, S. D.; St Cicort-lucaciu, A.

    2006-01-01

    In the Teuz River hydrographic basin from the western part of Romania we encountered 15 species of amphibians (Salamandra salamandra, Triturus vulgaris, Triturus cristatus, Triturus dobrogicus, Triturus alpestris, Bombina bombina, Bombina variegata, Bufo bufo, Bufo viridis, Hyla arborea, Pelobates fuscus, Rana ridibunda, Rana lessonae, Rana dalmatina, Rana temporaria), 8 species of reptiles (Emys orbicularis, Lacerta agilis, Lacerta viridis, Podarcis muralis, Anguis fragilis, Natrix natrix, C...

  1. The herpetofauna of the south-western part of Mehedin?i County, Romania

    OpenAIRE

    Ferent?i, Sara; Sas, Istva?n; Gaceu, Ovidiu; S? Cicort-lucaciu, Alfred; Covaciu-marcov, Severus D.; Bogdan, Horia Vlad

    2009-01-01

    . The south-western part of Mehedin?i County comprises many herpetofauna species, compared to most regions in Romania. This is how we managed to encounter 14 amphibian species (Salamandra salamandra, Lissotriton vulgaris, Triturus cristatus, Triturus dobrogicus, Bombina bombina, Bombina variegata, Pelobates fuscus, Bufo bufo, Bufo viridis, Hyla arborea, Pelophylax ridibundus, Pelophylax lessonae, Rana dalmatina, Rana temporaria) plus Pelophylax kl. esculentus and 15 reptile species (Emys orb...

  2. 76 FR 20004 - Endangered Species Recovery Permit Applications

    Science.gov (United States)

    2011-04-11

    ...handle, measure, and release) the arroyo toad (Anaxyrus californicus) and mountain yellow-legged frog (Rana muscosa) in conjunction...attach transmitters, and release) the arroyo toad (Anaxyrus californicus) and take (apply hormone treatments, conduct...

  3. Effects of insecticide formulations used in cotton cultivation in West Africa on the development of flat-backed toad tadpoles (Amietophrynus maculatus).

    Science.gov (United States)

    Stechert, Christin; Kolb, Marit; Rödel, Mark-Oliver; Bahadir, Müfit

    2015-02-01

    In the West African savanna zone, traditional subsistence farming increasingly shifts to cash crop farming and in particular to cotton cultivation, which is accompanied by application of pesticides. Increasing use of pesticides by smallholder farmers is suspected to have negative effects on non-target organisms. In this study, possible pesticide impact on the development of tadpoles was investigated. Two insecticide formulations used in cotton cultivation in Benin were compared: Cotofan® (active ingredient (a.i.): ?- and ?-endosulfan) and Tihan® (a.i.: spirotetramat and flubendiamide). Tadpoles of the widespread species Amietophrynus maculatus were kept in small water basins with increasing insecticide concentrations (1, 10 and 100 ?g a.i./L) over a period of 28?days. Tadpoles showed reduced survival at the highest endosulfan concentrations (100 ?g/L). Survival of tadpoles undergoing metamorphosis was not influenced by Tihan®. Endosulfan in concentrations of 10 and 100 ?g/L negatively impacted the movement of the tadpoles which was not the case for the mixture of spirotetramat and flubendiamide. Time to metamorphosis was not significantly different in the various treatments. Tail length of tadpoles was significantly shorter in Cotofan® treatments compared to controls. Pesticide residues in the tadpoles were relatively low after keeping them in concentrations of 1 and 10 ?g a.i./L (25 and 26 ?g/kg wet weight (w/w) for the sum of ?-endosulfan, ?-endosulfan and endosulfan sulphate and below the detection limits for flubendiamide and spirotetramat). For the 100 ?g a.i./L treatments, 1,600 ?g/kg w/w was found of ?-endosulfan, ?-endosulfan and endosulfan sulphate together in the survived tadpoles and 21 ?g/kg w/w of flubendiamide. PMID:25192667

  4. Effects of timber harvesting on pond-breeding amphibian persistence: testing the evacuation hypothesis.

    Science.gov (United States)

    Semlitsch, Raymond D; Conner, Christopher A; Hocking, Daniel J; Rittenhouse, Tracy A G; Harper, Elizabeth B

    2008-03-01

    Numerous studies have documented the decline of amphibians following timber harvest. However, direct evidence concerning the mechanisms of population decline is lacking and hinders attempts to develop conservation or recovery plans and solutions for forest species. We summarized the mechanisms by which abundance of amphibians may initially decline following timber harvest into three testable hypotheses: (1) mortality, (2) retreat, and (3) evacuation. Here, we tested the evacuation hypothesis within a large-scale, replicated experiment. We used drift fences with pitfall traps to capture pond-breeding amphibians moving out of experimental clearcut quadrants and into control quadrants at four replicate arrays located within the Daniel Boone Conservation Area on the upper Ozark Plateau in Warren County, Missouri, USA. During the preharvest year of 2004, only 51.6% of the 312 individuals captured were moving out of pre-clearcut quadrants, and movement did not differ from random. In contrast, during both postharvest years of 2005 and 2006, the number of captures along the quadrant edge increased, and a higher proportion of individuals (59.9% and 56.6%, respectively, by year) were moving out of clearcut quadrants than entering. Salamanders moved out of clearcuts in large percentages (Ambystoma annulatum, 78.2% in 2005, 78.2% in 2006; A. maculatum, 64.0% in 2005, 57.1% in 2006). Frogs and toads also moved out of clearcut quadrants, but in lower percentages (Bufo americanus, 59.6% in 2005, 53.3% in 2006; Rana clamitans, 52.7% in 2006). Salamanders moved out of clearcuts with low-wood treatments more than out of clearcuts with high-wood treatments. Movement of salamanders out of clearcuts was independent of sex. Estimated movement out of clearcuts represented between 8.7% and 35.0% of the total breeding adults captured for two species of salamanders. Although we recognize that some portion of the amphibian population may retreat underground for short periods and others may not survive the effects of timber harvest, these data are the first direct evidence showing that individuals are capable of leaving clearcuts and shifting habitat use. PMID:18488596

  5. Contribution to knowledge of the distribution of herpetofauna in Tarc?u Mountains (Romania

    Directory of Open Access Journals (Sweden)

    Daniel Ghiurc?

    2009-12-01

    Full Text Available In the researched area we identified 12 amphibian species: Salamandra salamndra, Lissotritonvulgaris, Triturus cristatus, Mesotriton alpestris, Lissotriton montandoni, Bombina variegata, Bufo bufo,Bufo viridis, Hyla arborea, Pelophylax ridibundus, Rana dalmatina and Rana temporaria and 9 reptilespecies: Lacerta agilis, Lacerta viridis, Zootoca vivipara, Podarcis muralis, Anguis fragilis, Natrix natrix,Zamenis longissimus, Coronella austriaca and Vipera berus. Within the region we identified speciesquoted (Cog?lniceanu et al. 2000, Ghiurc? et al. 2005, Gherghel et al. 2008, Iftime et al. 2008 to havethe lowest altitudinal limit of their spreading area at much higher altitudes. Most of the amphibian andreptilian species are not endangered in the researched area.

  6. Preliminary data concerning the distribution of amphibian fauna in Suceava county (Romania

    Directory of Open Access Journals (Sweden)

    Alexandru STRUGARIU

    2006-05-01

    Full Text Available The present study focused upon an area in which the herpetofauna had previously been very poorly studied and aimed to identify the species of amphibians from the research area and to establish distribution areas. In the 54 investigated localities 16 species of amphibians (Salamandra salamandra, Triturus vulgaris, Triturus cristatus, Triturus alpestris, Triturus montandoni, Pelobates fuscus, Bombina bombina, Bombina variegata, Hyla arborea, Bufo bufo, Bufo viridis, Rana dalmatina, Rana temporaria, Rana arvalis, Rana ridibunda & Rana lessonae and 2 hybrids (Bombina bombina X Bombina variegata & Rana kl. esculanta have been identified. Of these, the Bombina hybrids have been identified for the first time in the studied region.

  7. Valge fungi uus tulemine / Kersti Pikk

    Index Scriptorium Estoniae

    Pikk, Kersti

    2007-01-01

    Peeter Tambu projekteeritud valge "eestiaegne" funk eramu, kus avatud planeeringu asemel on paraja suurusega eraldi toad, esikohal ruumide otstarbekus ja ratsionaalsus. Arhitekt on kujundanud interjööri ja mööbli

  8. 76 FR 35235 - Endangered and Threatened Species Permit Applications

    Science.gov (United States)

    2011-06-16

    ...Bufo houstonensis), and black-footed ferret (Mustela nigripes) within the Fort Worth Zoo. Permit TE-43719A...sucker (Xyrauchen texanus), black-footed ferret (Mustela nigripes), Arizona cliffrose (Purshia subintegra),...

  9. del suborden myxophaga (insecta: coleoptera en la provincia del Golfo de Mexico

    Directory of Open Access Journals (Sweden)

    Roberto Arce P\\u00E9rez

    2008-01-01

    Full Text Available Members of the Coleoptera suborder Myxophaga: Lepicerus bufo Hinton (Lepiceridae and Sphaerius sp. (Sphaeriusidae are recorded by the first time for the lowlands of Gulf of Mexico in southern Veracruz, Mexico.

  10. Notice on the ocurrence of supernumerary teeth in the two-toad sloths Choloepus didactylus and C. hoffmanni / Noticias sobre la ocurrencia de dientes supernumerarios en perezosos de dos dedos, Choloepus didactylus y C. hoffmanni

    Scientific Electronic Library Online (English)

    Robert K, McAfee; Virginia L, Naples.

    2012-12-01

    Full Text Available Si bien casi todos los órdenes de mamíferos modernos presentan dientes supernumerarios, no se habían publicado casos entre pilosos vivientes. En este estudio se documentan dientes supernumerarios en tres individuos del género de perezosos Choloepus: dos C. hoffmani y un C. didactylus. Todos los dien [...] tes duplicados se encuentran en el maxilar derecho. Uno de los dos C. hoffmani presenta, además, un diente duplicado del lado izquierdo, lo que sugiere que la duplicación no es específica a nivel de taxón o lateralidad. Los dientes de los perezosos erupcionan como conos simples redondeados y, por lo tanto, la variedad de patrones cuspidales característicos de cada género se produce por el desgaste y el desplazamiento en el espacio de las denticiones superior e inferior. Abstract in english Supernumerary teeth occur in nearly all modern mammalian orders, although no previous cases have been published for extant pilosans. We report here three specimens of the sloth genus Choloepus, two C. hoffmanni and one C. didactylus, exhibiting supernumerary teeth. All duplicated teeth are maxillary [...] , and all but one on the right side. One C. hoffmanni bears an additional left tooth, suggesting duplication is neither species nor toothrow-side specific. Sloth teeth erupt as simple rounded cones and the different "cusp" patterns characteristic of each extant and extinct genus arise from wear and the differential spacing of upper versus lower dentitions.

  11. Amphibians of the Ausoni Mountains (Latium, Central Italy)

    OpenAIRE

    Antonio Romano; Luigi Corsetti

    2007-01-01

    In this study we searched for amphibians in 89 potential breeding sites within the Ausoni Mounts, which are among the less investigated areas of Latium. Sixtynine spawning sites, and eight amphibian species (57.1% of the 14 amphibian species living in Latium region) were found. Reproductive activity was recorded for Salamandrina perspicillata, Triturus carnifex, Lissotriton vulgaris, Lissotriton italicus, Bufo bufo, Hyla intermedia, Rana italica and Pelophylax synklepton hispanica.

  12. Amphibians of the Ausoni Mountains (Latium, Central Italy

    Directory of Open Access Journals (Sweden)

    Antonio Romano

    2007-11-01

    Full Text Available In this study we searched for amphibians in 89 potential breeding sites within the Ausoni Mounts, which are among the less investigated areas of Latium. Sixtynine spawning sites, and eight amphibian species (57.1% of the 14 amphibian species living in Latium region were found. Reproductive activity was recorded for Salamandrina perspicillata, Triturus carnifex, Lissotriton vulgaris, Lissotriton italicus, Bufo bufo, Hyla intermedia, Rana italica and Pelophylax synklepton hispanica.

  13. AcEST: DK953769 [AcEST

    Lifescience Database Archive (English)

    Full Text Available TST39A01NGRL0018_K13 622 Adiantum capillus-veneris mRNA. clone: TST39A01NGRL0018_K13. 5' end seq ... nine-protein kinase Eg2-like O... 31 5.9 sp|Q90252|MTR _BUFMA Mesotocin receptor OS=Bufo marinus PE=2 SV=1 ... KPTAQGLLRPATHGHQTSKPQGPNENRNPQQTSHS 106 >sp|Q90252|MTR _BUFMA Mesotocin receptor OS=Bufo marinus PE=2 SV=1 ...

  14. Notes on distribution and current status of herpetofauna in the northern area of Bra?ov County (Romania)

    OpenAIRE

    Sos, Tibor

    2007-01-01

    In the northern area of Bra?ov County, the herpetofauna appears to be characteristic for a hilly and low-mountain zone and includes the following species: Salamandra salamandra, Triturus cristatus, Lissotriton vulgaris, Bombina variegata, Pelobates fuscus, Bufo bufo, Pseudepidalea viridis, Hyla arborea, Pelophylax ridibundus, Pelophylax kl. esculentus, Rana dalmatina, Rana temporaria, Rana arvalis, Emys orbicularis, Lacerta agilis, Lacerta viridis, Podarcis muralis, Anguis fragilis colchicus...

  15. The herpetofauna of the Great Ulcinj Beach area including Ada Island (Montenegro)

    OpenAIRE

    Polovic, Lidija; Cadenovic, Natalija

    2014-01-01

    In this paper, we present the results of a study conducted in the Great Ulcinj Beach area, including its hinterland and Ada Island. In the study area, we recorded 10 species of amphibians (Lissotriton vulgaris, Bombina variegata, Bufo bufo, Pseudepidalea viridis, Hyla arborea, Pelophylax ridibundus, Pelophylax lessonae, Pelophylax shqipericus, Rana dalmatina, and Rana temporaria) and 20 species of reptiles (Testudo hermanni, Emys orbicularis, Mauremys rivulata, Caretta caretta, Hemidactylus t...

  16. Morphological distinction between filaments that converge upon desmosomes and those that are attached to hemidesmosomes in the epidermis of anuran larvae and lampreys.

    OpenAIRE

    Joazeiro, P P; Montes, G S

    1991-01-01

    Two populations of morphologically distinct intermediate filaments which are segregated into different compartments of the cytoplasm and which may attach to different junctional specialisations were observed in the basal layer cells of the epidermis of tadpoles of Rana catesbeiana, Rana temporaria, Bufo bufo, Leptodactylus flavopictus and Pseudis paradoxus and in the skin of the adult lamprey, Lampetra planeri. These two distinct populations of cytokeratin intermediate filaments were recognis...

  17. A Symbolic Finite-state approach for Automated Proving of Theorems in Combinatorial Game Theory

    CERN Document Server

    Thanatipanonda, Thotsaporn ``Aek''

    2007-01-01

    We develop a finite-state automata approach, implemented in a Maple package {\\tt ToadsAndFrogs} available from our websites, for conjecturing, and then rigorously proving, values for large families of positions in Richard Guy's combinatorial game ``Toads and Frogs''. In particular, we prove a conjecture of Jeff Erickson.

  18. Evidence of phoresy by leeches (Hirudinoidea on Rhinella abei (Anura: Bufonidae in the Atlantic Rainforest in the state of Santa Catarina, southern Brazil

    Directory of Open Access Journals (Sweden)

    Carlos Frederico Duarte Rocha

    2012-07-01

    Full Text Available In the Atlantic Rainforest of the Parque Estadual da Serra do Tabuleiro, state of Santa Catarina, southern Brazil, we found Rhinella abei (Bufonidae infested by leeches (Hirudinoidea. We captured 27 toads on the margin of a lagoon both inside and outside water in a survey carried out during one night, and 13 of which had a total of 30 leeches (mean intensity of infestation = 2.3 ± 1.3. We did not observe wounds, scars and/or hemorrhages caused by the leeches on the toads examined, no hemorrhaging after the removal of the leeches, and the leeches removed from the toads were empty of blood. This evidence led us to theorize that the leeches were not parasitizing the toads but had a phoretic relationship. The leeches were found on both dorsal and ventral surfaces (13 on each of the toads and were predominantly on the toads’ axils followed by back and thighs. The average snout-vent length of the toads was 69.2 ± 5.3 mm and their average body mass was 27.1 ± 6.9 g. The number of leeches found on a toad was not related to its snout-vent length or body mass. We are unaware of any previous records of leeches using anurans as dispersal agents, as suggested in the present study.

  19. Nomenclatural notes on living and fossil amphibians

    Directory of Open Access Journals (Sweden)

    Martín, C.

    2012-06-01

    Full Text Available A review of extinct and living amphibians known from fossils (Allocaudata, Anura and Caudata has revealed several cases that require nomenclatural changes in order to stabilize the taxonomy of the group. Nomenclatural changes include homonym replacements, corrections of spelling variants and authorships, name availabilities, and in particular, the proposal of new combinations. These changes will allow the incorporation of some palaeontological taxa to the current evolutionary models of relationship of modern forms based on molecular phylogenies. Rana cadurcorum for Rana plicata Filhol, 1877, Rana auscitana for Rana pygmaea Lartet, 1851, and Rana sendoa for Rana robusta Brunner, 1956. Anchylorana Taylor, 1942 is considered a new synonym of Lithobates Fitzinger, 1843. New combinations proposed are: Anaxyrus defensor for Bufo defensor Meylan, 2005; Anaxyrus hibbardi for Bufo hibbardi Taylor, 1937; Anaxyrus pliocompactilis for Bufo pliocompactilis Wilson, 1968; Anaxyrus repentinus for Bufo repentinus Tihen, 1962; Anaxyrus rexroadensis for Bufo rexroadensis Tihen, 1962; Anaxyrus spongifrons for Bufo spongifrons Tihen, 1962; Anaxyrus suspectus for Bufo suspectus Tihen, 1962; Anaxyrus tiheni for Bufo tiheni Auffenberg, 1957; Anaxyrus valentinensis for Bufo valentinensis Estes et Tihen, 1964; Ichthyosaura wintershofi for Triturus wintershofi Lunau, 1950; Incilius praevius for Bufo praevius Tihen, 1951; Lithobates bucella for Rana bucella Holman, 1965; Lithobates dubitus for Anchylorana dubita Taylor, 1942; Lithobates fayeae for Rana fayeae Taylor, 1942; Lithobates miocenicus for Rana miocenica Holman, 1965; Lithobates moorei for Anchylorana moorei Taylor, 1942; Lithobates parvissimus for Rana parvissima Taylor, 1942; Lithobates rexroadensis for Rana rexroadensis Taylor, 1942; Lithobates robustocondylus for Anchylorana robustocondyla Taylor, 1942; Ommatotriton roehrsi for Triturus roehrsi Herre, 1955; Pelophylax barani for Rana barani Rückert-Ülkumen, 1980; Pelophylax meriani for Rana meriani Meyer, 1853; Pelophylax pueyoi for Rana pueyoi Navás, 1922a; Pelophylax quellenbergi for Rana quellenbergi Navás, 1922; Philoria borealis for Kyarranus borealis Tyler, 1991; Pseudepidalea belogorica for Bufo belogoricus Ratnikov, 1993; Pseudepidalea plana for Bufo planus Ratnikov, 1993; Pseudepidalea prisca for Bufo priscus Spinar, Klembara et Meszáros, 1993, and Pseudepidalea stranensis for Bufo stranensis Nemec, 1972. The names Geyeriellinae Brame, 1958, Palaeurodelidae Brame, 1958, Prosalamandridae Stefano, 1903, Lipelucidae Huene, 1956, Rana temporaria fossilis Stefanov, 1951, Salteniidae Kuhn, 1962, Vieraellidae Reig, 1961, and Voigtiellinae Brame, 1958 are nomenclaturally deemed unavailable. The family name based on Scapherpeton Cope, 1876 is Scapherpetidae and not Scapherpetonidae nor Scapherpetontidae.

    Una revisión de anfibios extintos

  20. Host–parasite interactions during a biological invasion: The fate of lungworms (Rhabdias spp. inside native and novel anuran hosts

    Directory of Open Access Journals (Sweden)

    Felicity B.L. Nelson

    2015-08-01

    Full Text Available The cane toad invasion in Australia provides a robust opportunity to clarify the infection process in co-evolved versus de novo host–parasite interactions. We investigated these infection dynamics through histological examination following experimental infections of metamorphs of native frogs (Cyclorana australis and cane toads (Rhinella marina with Rhabdias hylae (the lungworm found in native frogs and Rhabdias pseudosphaerocephala (the lungworm found in cane toads. Cane toads reared under continuous exposure to infective larvae of the frog lungworm were examined after periods of 2, 6, 10 and 15 days. Additionally, both toads and frogs were exposed for 24?h to larvae of either the toad or the frog lungworm, and examined 2, 5, 10 and 20 days post-treatment. R. hylae (frog lungworms entered cane toads and migrated through the body but were not found in the target tissue, the lungs. Larvae of both lungworm species induced inflammation in both types of hosts, although the immune response (relative numbers of different cell types differed between hosts and between parasite species. Co-evolution has modified the immune response elicited by infection and (perhaps for that reason has enhanced the parasite's ability to survive and to reach the host's lungs.

  1. Host-parasite interactions during a biological invasion: The fate of lungworms (Rhabdias spp.) inside native and novel anuran hosts.

    Science.gov (United States)

    Nelson, Felicity B L; Brown, Gregory P; Shilton, Catherine; Shine, Richard

    2015-08-01

    The cane toad invasion in Australia provides a robust opportunity to clarify the infection process in co-evolved versus de novo host-parasite interactions. We investigated these infection dynamics through histological examination following experimental infections of metamorphs of native frogs (Cyclorana australis) and cane toads (Rhinella marina) with Rhabdias hylae (the lungworm found in native frogs) and Rhabdias pseudosphaerocephala (the lungworm found in cane toads). Cane toads reared under continuous exposure to infective larvae of the frog lungworm were examined after periods of 2, 6, 10 and 15 days. Additionally, both toads and frogs were exposed for 24?h to larvae of either the toad or the frog lungworm, and examined 2, 5, 10 and 20 days post-treatment. R. hylae (frog) lungworms entered cane toads and migrated through the body but were not found in the target tissue, the lungs. Larvae of both lungworm species induced inflammation in both types of hosts, although the immune response (relative numbers of different cell types) differed between hosts and between parasite species. Co-evolution has modified the immune response elicited by infection and (perhaps for that reason) has enhanced the parasite's ability to survive and to reach the host's lungs. PMID:25973392

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

    Directory of Open Access Journals (Sweden)

    Luca Tringali

    2010-07-01

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

  3. Presidendi külalismaja avatakse turistidele märtsis / Kadri Paas

    Index Scriptorium Estoniae

    Paas, Kadri, 1982-

    2007-01-01

    President Toomas Hendrik Ilvese ja proua Evelin Ilvese Ärma talu- ja puhkekompleks Erma Park Abja-Paluoja naabruses avatakse külalistele 2007. a. märtsis. Külaliste toad kannavad tuntud ajalooliste ühiskonna- ja kultuuritegelaste nimesid

  4. Environ: E00121 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available E00121 Toad venom (JP16) Crude drug Hellebrin [CPD:C08868], Resibufogenin [CPD:C17058], Cinobufa ... [CPD:C08278], Arginine [CPD:C00062], Arenobufagin, phi -Bufarenogin, Cinobufaginol, Marinobufagin, Resibuf ...

  5. Dynamic characterization of silicon nanowires using a terahertz optical asymmetric demultiplexer-based pump-probe scheme

    DEFF Research Database (Denmark)

    Ji, Hua; Cleary, C. S.

    2012-01-01

    Dynamic phase and amplitude all-optical responses of silicon nanowires are characterized using a terahertz optical asymmetric demultiplexer (TOAD) based pump-probe scheme. Ultra-fast recovery is observed for moderate pump powers.

  6. Amphibian abnormalities on National Wildlife Refuges

    US Fish and Wildlife Service, Department of the Interior — This fact sheet outlines a study done to 1 find the percentage of abnormal frogs and toads on the nations National Wildlife Refuges and 2 determine how the...

  7. Drug: D06750 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D06750 Crude, Drug Toad venom (JP16) Hellebrin [CPD:C08868], Resibufogenin [CPD:C17058], Cinobuf ... Suberic acid [CPD:C08278], Arginine [CPD:C00062], Arenobufagin , phi-Bufarenogin, Cinobufaginol, Marinobufagin, Re ...

  8. Instruction Manual and Frog Survey Protocols for Region 1 National Wildlife Refuges, East-side Zone

    US Fish and Wildlife Service, Department of the Interior — This manual is intended to assist biologists wishing to conduct surveys for frogs and toads. The document includes detailed information on how to conduct surveys,...

  9. Predation of Molossus molossus (Pallas, 1766 (Chiroptera: Molossidae by Rhinella jimi (Stevaux, 2002 (Anura: Bufonidae in the Caatinga, Pernambuco, Brazil

    Directory of Open Access Journals (Sweden)

    Luiz Augustinho Menezes da Silva

    2010-06-01

    Full Text Available This communication is to report, through a fortuitous event, the predation of the bat Molossus molossus by the toad Rhinella jimi, on 29 May 2003 in the Caatinga, municipality of Orocó, state of Pernambuco, northeast Brazil.

  10. Formicine ants: An arthropod source for the pumiliotoxin alkaloids of dendrobatid poison frogs

    OpenAIRE

    Saporito, Ralph A; Garraffo, H. Martin; Donnelly, Maureen A.; Edwards, Adam L.; Longino, John T.; DALY, JOHN W.

    2004-01-01

    A remarkable diversity of bioactive lipophilic alkaloids is present in the skin of poison frogs and toads worldwide. Originally discovered in neotropical dendrobatid frogs, these alkaloids are now known from mantellid frogs of Madagascar, certain myobatrachid frogs of Australia, and certain bufonid toads of South America. Presumably serving as a passive chemical defense, these alkaloids appear to be sequestered from a variety of alkaloid-containing arthropods. The pumiliotoxins represent a ma...

  11. Gene : CBRC-XTRO-01-3153 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-XTRO-01-3153 Novel UN A Vasopressin / oxytocin receptors MTR _BUFMA 0.0 85% sp|Q90252|MTR _BU ... FMA Mesotocin receptor (MTR ) emb|CAA63713.1| mesotocin receptor [Bufo marinus] ...

  12. Relationship between the genetic structure of the Andean toad Rhinella spinulosa (Anura: Bufonidae) and the northern Chile landscape (21°- 24° S) / Relación entre la estructura genética del sapo andino Rhinella spinulosa (Anura: Bufonidae) y el paisaje del norte de Chile (21°- 24° S)

    Scientific Electronic Library Online (English)

    CAROLINA E, GALLARDO; HÉCTOR J, HERNÁNDEZ; JOSÉ A. F, DINIZ-FILHO; R. EDUARDO, PALMA; MARCO A, MÉNDEZ.

    2011-09-01

    Full Text Available Se evaluó la relación entre las características del paisaje y ambientales y la diferenciación genética de Rhinella spinulosa en el altiplano de la Región de Antofagasta (Chile). Para esto se realizaron tres tipos de análisis a diferentes escalas espaciales: (1) considerando todas las poblaciones; (2 [...] ) agrupando las poblaciones por cuencas y por subcuencas; y (3) utilizando los resultados del análisis espacial de variación molecular (SAMOVA). Las características del paisaje se incorporaron diseñando tres modelos hipotéticos de dispersión con los Sistemas de Información Geográfico: (1) distancia euclidiana (modelo nulo); (2) de menor costo basado en la localización de los humedales; y (3) de menor costo basado en las pendientes menores. Además, se incluyeron las diferencias en temperatura, precipitación y altitud entre localidades. Para seleccionar el modelo que mejor explicara la diferenciación genética se utilizó el Criterio de Información de Akaike y se estimó la importancia relativa de cada variable del modelo seleccionado utilizando regresiones parciales. Se encontró una alta diferenciación genética entre las poblaciones (Fst = 0.693) y un patrón claro de aislamiento por distancia (r = 0.767). El análisis AMOVA mostró que las cuencas explicaron un 8.67 % de la varianza genética y las subcuencas un 35.99 %. A mayor escala espacial, considerando todas las poblaciones, el mejor modelo que explicó la diferenciación genética incluyó las variables distancia euclidiana, altitud y precipitación anual. A menor escala, en dos de las tres subcuencas (Río San Pedro y Salar de Atacama) la diferenciación genética fue mejor explicada por variables del paisaje (temperatura y altitud, principalmente). A menor escala, considerando las poblaciones que han divergido recientemente detectadas por SAMOVA, la diferenciación genética fue mejor explicada por la ruta basada en humedales y la precipitación anual. Esta aproximación muestra la importancia de las características del paisaje en la colonización de R. spinulosa en esta zona. Abstract in english We analyzed the relationship of landscape and environmental features on the genetic differentiation of Rhinella spinulosa (Wiegmann, 1834) in the Altiplano of Antofagasta (Chile). We performed three types of analyses at different spatial scales: (1) Considering all populations; (2) Grouping populati [...] ons by watershed and by sub-watershed; and (3) Using the results of a spatial analysis of molecular variation (SAMOVA). Landscape features were incorporated using Geographic Information Systems, with three hypothetical dispersal models: (1) Euclidean distance (null model); (2) Least cost based on wetland locations; and (3) Least cost based on least slopes. We also included differences in temperature, precipitation and altitude among localities. The Akaike information criterion was used to select the best model and the relative importance of each variable in the model was estimated with partial regressions. We found a high genetic differentiation among populations (Fst = 0.693) and isolation by distance (r = 0.767). AMOVA showed that the watersheds explained 8.67 % of the genetic variance and sub-watersheds 35.99 %. At the largest spatial scale, considering all populations, the model that best explained genetic differentiation included Euclidean distance, altitude and annual precipitation. At a smaller scale, in two of three sub-watersheds (Río San Pedro and Salar de Atacama) the genetic differentiation was best explained by landscape variables (principally temperature and altitude). At the smallest scale, considering those populations that have diverged recently detected by SAMOVA, the genetic differentiation was best explained by the wetland-based route and annual precipitation. This approach revealed the importance of landscape features in the colonization of R. spinulosa in this zone.

  13. A hybrid zone of two toad sister species, Rhinella atacamensis and R. arunco (Anura: Bufonidae), defined by a consistent altitudinal segregation in watersheds / Una zona de hibridación de dos especies hermanas de anuros, Rhinella atacamensis y R. arunco (Anura: Bufonidae), definida por una consistente segregación altitudinal en cuencas hidrográficas

    Scientific Electronic Library Online (English)

    CLAUDIO, CORREA; MARCO A, MÉNDEZ; SERGIO, ARAYA; GABRIEL, LOBOS; R. EDUARDO, PALMA.

    2013-06-01

    Full Text Available Definir la extensión espacial de una zona de hibridación es esencial para entender su origen histórico e identificar los factores geográficos y/o ambientales que la delimitan. Rhinella atacamensis y R. arunco son dos especies hermanas que en conjunto habitan entre los 25 y 38° S a lo largo de Chile. [...] Sus límites de distribución coinciden aproximadamente a los 32° S, donde recientemente se reportó que hibridan en una pequeña cuenca hidrográfica (estero Pupío). Aunque la evidencia genética sugiere que estas especies forman un enjambre híbrido, no se mezclan homogéneamente a lo largo de la cuenca sino que se segregan espacialmente: R. arunco se encuentra en la parte baja del estero, mientras que R. atacamensis se ubica en la parte alta. Una extensa exploración al norte y sur de los 32° S reveló otras instancias de hibridación donde se mantiene el mismo patrón de segregación espacial dentro de otras cuencas. En este estudio se describe esta zona de hibridación combinando secuencias mitocondriales y marcadores nucleares AFLP. En su parte norte, la zona conforma una estrecha franja que atraviesa varias cuencas extendiéndose más de 130 km en dirección noroeste-sureste, de manera que R. atacamensis se encuentra cada vez a mayor altura a medida que se avanza hacia el sur. Sin embargo, dos puntos ubicados el sur de esta franja muestran que la zona de hibridación es más extensa y compleja, y que probablemente se extiende por todo el borde de las cadenas de cerros que conforman la cuenca hidrográfica del río Aconcagua (32°30' - 33° S). Se plantea una explicación para el origen de esta zona de hibridación considerando antecedentes paleoclimáticos y orográficos y se discuten brevemente las implicancias taxonómicas de estos resultados. Abstract in english Delimiting the spatial extension of a hybrid zone is essential to understand its historical origin and to identify the geographical and/or environmental factors which delimit it. Rhinella atacamensis and R. arunco are two sister species which together inhabit Chile between 25° and 38° S. Their distr [...] ibution limits coincide at about 32° S, where recently it was reported that they hybridize in a small watershed (Pupío creek). Although the genetic evidence suggests that these two species form a hybrid swarm, they are not mixed homogeneously in the entire watershed, but rather are spatially segregated: R. arunco is found in the lower part of the creek and R. atacamensis in the higher part. An extensive exploration north and south of 32° S revealed other instances of hybridization, with the same pattern of spatial segregation within other watersheds. This study describes the hybrid zone combining mitochondrial sequences and nuclear AFLP markers. In the northern part, the hybrid zone is a narrow strip which crosses several watersheds and extends more than 130 km from NW-SE, so that R. atacamensis is found at higher altitudes towards the south. However, two points south of this strip show that the hybrid zone is more extensive and complex, and probably extends along the entire border of the mountain chains which form the watershed of the Aconcagua River (32°30' - 33° S). We propose an explanation for the origin of this hybrid zone considering paleoclimatic and orographic information, and briefly discuss the taxonomic implications of these results.

  14. Geographic variation in Incilius occidentalis (Anura: Bufonidae), an endemic toad from Mexico, with a redescription of the species and delimitation of the type locality / Variación geográfica en Incilius occidentalis (Anura: Bufonidae), un sapo endémico de México, con una redescripción de la especie y delimitación de la localidad tipo

    Scientific Electronic Library Online (English)

    Georgina, Santos-Barrera.

    Full Text Available En este trabajo se revisó la variación geográfica en la morfometría de las poblaciones que conforman la especie Incilius occidentalis, que se distribuye ampliamente en el noroeste y centro de México; se presenta además una revisión de la historia nomenclatural de esta especie. Para analizar la varia [...] ción morfométrica se definieron 33 poblaciones provenientes de más de 220 localidades, midiéndose diez variables morfométricas estandar y otras de morfología externa en ejemplares adultos. El análisis de componentes principales (ACP) muestra que la variación observada se concentra en la variable LHC, sin embargo, la prueba de Tukey-HSD para analizar diferencias interpoblacionales mostró que no existen poblaciones morfométricamente distinguibles dentro de esta especie. La forma y el tamaño del cuerpo son similares entre las poblaciones, lo que sugiere la idea de que la forma típica que define a los bufónidos puede confirmarse en esta especie. I. occidentalis se redescribe mediante la comparación de los 3 ejemplares tipo depositados en la Colección Antigua de la Universidad de Turín, Italia y más de 850 ejemplares depositados en diferentes colecciones herpetológicas. Se designan un lectotipo y 2 paralectotipos, y se define la distribución geográfica de esta especie, restringiendo la localidad tipo en la ciudad de Guanajuato y alrededores. Abstract in english A taxonomic revision of the populations referable to the wide ranging species Incilius occidentalis was conducted based on 10 morphometric variables and other external morphological traits. Thirty three populations were geographically defined from more than 220 locality records of the species. A bri [...] ef summary of the nomenclatural history of this species is presented and the external morphological variation is analyzed. Incilius occidentalis is here redescribed on the basis of comparisons with the 3 specimens housed at the Old Collection of the Torino Museum, and over 850 specimens held at several herpetological collections. Statistical analysis using principal components analysis (PCA) demonstrated that SVL concentrates the main part of the variance observed in these populations. No distinguishable populations were detected on the basis of morphometric differences using the Tukey HSD analysis. Body proportions are fairly similar between the 33 populations defined, suggesting the idea that the typical body shape of the bufonid genera is also perceived in this species. The species I. occidentalis is fully redescribed, 1 lectotype and 2 paralectotypes are designated. The geographic range of this species is accurately defined and the type locality is restricted to the City of Guanajuato, and surroundings, Mexico.

  15. Relationship between the genetic structure of the Andean toad Rhinella spinulosa (Anura: Bufonidae and the northern Chile landscape (21°- 24° S Relación entre la estructura genética del sapo andino Rhinella spinulosa (Anura: Bufonidae y el paisaje del norte de Chile (21°- 24° S

    Directory of Open Access Journals (Sweden)

    CAROLINA E GALLARDO

    2011-09-01

    Full Text Available We analyzed the relationship of landscape and environmental features on the genetic differentiation of Rhinella spinulosa (Wiegmann, 1834 in the Altiplano of Antofagasta (Chile. We performed three types of analyses at different spatial scales: (1 Considering all populations; (2 Grouping populations by watershed and by sub-watershed; and (3 Using the results of a spatial analysis of molecular variation (SAMOVA. Landscape features were incorporated using Geographic Information Systems, with three hypothetical dispersal models: (1 Euclidean distance (null model; (2 Least cost based on wetland locations; and (3 Least cost based on least slopes. We also included differences in temperature, precipitation and altitude among localities. The Akaike information criterion was used to select the best model and the relative importance of each variable in the model was estimated with partial regressions. We found a high genetic differentiation among populations (Fst = 0.693 and isolation by distance (r = 0.767. AMOVA showed that the watersheds explained 8.67 % of the genetic variance and sub-watersheds 35.99 %. At the largest spatial scale, considering all populations, the model that best explained genetic differentiation included Euclidean distance, altitude and annual precipitation. At a smaller scale, in two of three sub-watersheds (Río San Pedro and Salar de Atacama the genetic differentiation was best explained by landscape variables (principally temperature and altitude. At the smallest scale, considering those populations that have diverged recently detected by SAMOVA, the genetic differentiation was best explained by the wetland-based route and annual precipitation. This approach revealed the importance of landscape features in the colonization of R. spinulosa in this zone.Se evaluó la relación entre las características del paisaje y ambientales y la diferenciación genética de Rhinella spinulosa en el altiplano de la Región de Antofagasta (Chile. Para esto se realizaron tres tipos de análisis a diferentes escalas espaciales: (1 considerando todas las poblaciones; (2 agrupando las poblaciones por cuencas y por subcuencas; y (3 utilizando los resultados del análisis espacial de variación molecular (SAMOVA. Las características del paisaje se incorporaron diseñando tres modelos hipotéticos de dispersión con los Sistemas de Información Geográfico: (1 distancia euclidiana (modelo nulo; (2 de menor costo basado en la localización de los humedales; y (3 de menor costo basado en las pendientes menores. Además, se incluyeron las diferencias en temperatura, precipitación y altitud entre localidades. Para seleccionar el modelo que mejor explicara la diferenciación genética se utilizó el Criterio de Información de Akaike y se estimó la importancia relativa de cada variable del modelo seleccionado utilizando regresiones parciales. Se encontró una alta diferenciación genética entre las poblaciones (Fst = 0.693 y un patrón claro de aislamiento por distancia (r = 0.767. El análisis AMOVA mostró que las cuencas explicaron un 8.67 % de la varianza genética y las subcuencas un 35.99 %. A mayor escala espacial, considerando todas las poblaciones, el mejor modelo que explicó la diferenciación genética incluyó las variables distancia euclidiana, altitud y precipitación anual. A menor escala, en dos de las tres subcuencas (Río San Pedro y Salar de Atacama la diferenciación genética fue mejor explicada por variables del paisaje (temperatura y altitud, principalmente. A menor escala, considerando las poblaciones que han divergido recientemente detectadas por SAMOVA, la diferenciación genética fue mejor explicada por la ruta basada en humedales y la precipitación anual. Esta aproximación muestra la importancia de las características del paisaje en la colonización de R. spinulosa en esta zona.

  16. A New Time-Based Algorithm for Positioning Mobile Terminals in Wireless Networks

    Directory of Open Access Journals (Sweden)

    Francisco Barcelo-Arroyo

    2008-03-01

    Full Text Available This paper presents a positioning algorithm, named time of arrival to time difference of arrival (TOAD, which computes time-difference-of-arrival (TDOA measurements from the messages that time-of-arrival (TOA stations in sight exchange while their positioning processes are running. This study addresses the accuracy of the TOAD algorithm in two different environments: line-of-sight (LOS and non-line-of-sight (NLOS. Simulation is used to set up a wireless network. The Gauss-Newton nonlinear least squares algorithm is used to compute the positions in both TOA and TOAD stations. Results indicate that the TOAD algorithm increases the root mean square error (RMSE of the positioning error in LOS scenarios by 10 to 20% compared with the RMSE achieved by TOA. This drop in accuracy contrasts with the results for the NLOS scenarios. The RMSE of TOAD in such scenarios is at least 10% lower than that achieved by TOA. This result is specially important since this latter scenario is the most common. Consequently, this novel technique therefore improves the scalability and integrity of TOA techniques based on RTT, making it possible for the stations to position themselves without injecting traffic and with QoS figures close and most times better than that achieved by TOA.

  17. 7ª Contribuição ao estudo dos Flebotomus (Diptera: Psychodidae: descrição dos machos de 24 novas espécies

    Directory of Open Access Journals (Sweden)

    O. Mangabeira Filho

    1942-01-01

    Full Text Available The A. and his co-workers captured in trips in the hinterland of Brazil more tham 17.000 flebotomi from which 35 are new ones, 11 discribed by, him in previous papers. The A. found these insects in groups of species living in different habitats, some ones of them not yet known: ondoors, or outdoors attracted by light or animal baits, without Shannon’s trap, in great or small caves, in the jungle in tree’s holes, holes in stones, holes in the soil habited by animals like armadillos, pacas (Aguti paca, wild rats, cururú toad (Bufo sp.. He observed the life history of 13 species: Flebotomus longipalpis Lutz& Neiva, 1912, Flebotomus intermedius Lutz & Neiva, 1912, Flebotomus avellari Costa Lima, 1932, Flebotomus aragãoi costa Lima, 1932, Flebotomus lutzianus Costa Lima, 1932, Flebotomus limai fonseca, 1935, Flebotomus rickardi Costa Lima, 1936, Flebotomus dasipodogeton Castro, 1939, Flebotomus oswaldoi n. sp., Flebotomus villelai n. sp., Flebotomus triacanthus n. sp., Flebotomus longispinus n. sp. And flebotomus travassosi n. sp. He describes the male of 24 n. sp., explaining the differential diagnose of group or nearly allied species. He inclued F. rooti n. sp. And F. hirsutus n. sp. In the sub-genus Shannonomyia. The first one, very allied to F. davisi Root is different from it, for presenting in the dorsal side of the abdomen bristles and not scales and to have the median claspers longer than his inner appendage and F. hirsutus quite different from the others which show 3 spines on distal segment of the upper clasper and for being the only one who presents the bristles of inner appendage of median clasper longer than it. Only the females of F. amazonensis Root and f. chagasi Costa Lima, are known and then it is possible that they belong to one of the species of this sub-genus from whom only the male have been described. F. choti Floch & Abonnenc, captured also at Pará, F. triacanthus n. sp. F. trispinosus n. sp. And F. equatorialis n. sp. Are very related and to this group the A. proposes the same of Pressatia as sub-genus in honor to whom demonstrated the medical importance of the flebotomi, considering F. triacanthus as the type specie of this sub-genus. In this sub-genus the V papal joint is very long, longer than III + IV, the antennae with geniculated spines without posterior outgrowth. At the genitalia the basal segment of the upper clasper presents two types of bristles ou the inner face, arranged in tuft; the distal segment with 3 spines and 2 thin bristles something difficult to see one of them situated near the apical spine and the other on the base of tubercle where the median spine is articulated; the median clasper is unarmed and compressed; the inferior clasper is also unarmed and longer than de basal segment of the upper clasper; the pompeta is longer than the basal segment of the upper clasper. Following it is presented a key for the determination of the males of the four species of this sub-genus. F. micropygus n. sp., F. minasensis n. sp. e F. dandrophylus n. sp., f. shannoni, F. monticolus, F. pestanai, F. lanei and F. cayenensis constitute a group with many similars characters. F. micropygus is the only American species who present ? smaller than ? and for that reason and others is allied to. F. minuts and others related species, but presents two terminal spines on the distal segment of the upper clasper. F. micropygus and f. minasensis are quite different because they have very small genitalia, smaller than their heads. F. dendrophylus presents on the median clasper a naked area near the apex and for this and others characters is different from the others of the group. F. flaviscutellatus n. sp., F. oliverioi, F. intermedius and whithmani, are very allied but the first one can be very easily distinguished because it’s scutellum is light. Flebotomus barrettoi n. sp., F. coutinhoi n. sp., F. aragãoi, F. brasiliensis, F. lutzianus, F. texanus, F. pascalei, F. atroclavatus and F. tejeraae are very allied forming a natural group. The two last ones are not well known

  18. 7ª Contribuição ao estudo dos Flebotomus (Diptera: Psychodidae): descrição dos machos de 24 novas espécies

    Scientific Electronic Library Online (English)

    O., Mangabeira Filho.

    Full Text Available [...] Abstract in english The A. and his co-workers captured in trips in the hinterland of Brazil more tham 17.000 flebotomi from which 35 are new ones, 11 discribed by, him in previous papers. The A. found these insects in groups of species living in different habitats, some ones of them not yet known: ondoors, or outdoors [...] attracted by light or animal baits, without Shannon’s trap, in great or small caves, in the jungle in tree’s holes, holes in stones, holes in the soil habited by animals like armadillos, pacas (Aguti paca), wild rats, cururú toad (Bufo sp.). He observed the life history of 13 species: Flebotomus longipalpis Lutz& Neiva, 1912, Flebotomus intermedius Lutz & Neiva, 1912, Flebotomus avellari Costa Lima, 1932, Flebotomus aragãoi costa Lima, 1932, Flebotomus lutzianus Costa Lima, 1932, Flebotomus limai fonseca, 1935, Flebotomus rickardi Costa Lima, 1936, Flebotomus dasipodogeton Castro, 1939, Flebotomus oswaldoi n. sp., Flebotomus villelai n. sp., Flebotomus triacanthus n. sp., Flebotomus longispinus n. sp. And flebotomus travassosi n. sp. He describes the male of 24 n. sp., explaining the differential diagnose of group or nearly allied species. He inclued F. rooti n. sp. And F. hirsutus n. sp. In the sub-genus Shannonomyia. The first one, very allied to F. davisi Root is different from it, for presenting in the dorsal side of the abdomen bristles and not scales and to have the median claspers longer than his inner appendage and F. hirsutus quite different from the others which show 3 spines on distal segment of the upper clasper and for being the only one who presents the bristles of inner appendage of median clasper longer than it. Only the females of F. amazonensis Root and f. chagasi Costa Lima, are known and then it is possible that they belong to one of the species of this sub-genus from whom only the male have been described. F. choti Floch & Abonnenc, captured also at Pará, F. triacanthus n. sp. F. trispinosus n. sp. And F. equatorialis n. sp. Are very related and to this group the A. proposes the same of Pressatia as sub-genus in honor to whom demonstrated the medical importance of the flebotomi, considering F. triacanthus as the type specie of this sub-genus. In this sub-genus the V papal joint is very long, longer than III + IV, the antennae with geniculated spines without posterior outgrowth. At the genitalia the basal segment of the upper clasper presents two types of bristles ou the inner face, arranged in tuft; the distal segment with 3 spines and 2 thin bristles something difficult to see one of them situated near the apical spine and the other on the base of tubercle where the median spine is articulated; the median clasper is unarmed and compressed; the inferior clasper is also unarmed and longer than de basal segment of the upper clasper; the pompeta is longer than the basal segment of the upper clasper. Following it is presented a key for the determination of the males of the four species of this sub-genus. F. micropygus n. sp., F. minasensis n. sp. e F. dandrophylus n. sp., f. shannoni, F. monticolus, F. pestanai, F. lanei and F. cayenensis constitute a group with many similars characters. F. micropygus is the only American species who present ? smaller than ? and for that reason and others is allied to. F. minuts and others related species, but presents two terminal spines on the distal segment of the upper clasper. F. micropygus and f. minasensis are quite different because they have very small genitalia, smaller than their heads. F. dendrophylus presents on the median clasper a naked area near the apex and for this and others characters is different from the others of the group. F. flaviscutellatus n. sp., F. oliverioi, F. intermedius and whithmani, are very allied but the first one can be very easily distinguished because it’s scutellum is light. Flebotomus barrettoi n. sp., F. coutinhoi n. sp., F. aragãoi, F. brasiliensis, F. lutzianus, F. texanus, F. pascalei, F. atroclavatus and F. tejeraae are very allied forming a natural group. The two las

  19. [Electrophoretic mobility and activity Na,K-ATPase of erytheocytes in rats under stress].

    Science.gov (United States)

    Krylov, V N; Deriugina, A V; Konstantinova, A I

    2014-11-01

    In this paper, we study the relation between the electrophoretic mobility of erythrocytes (EPME) and the activity of Na,K-ATPase of erythrocytes under the action of different types of stress factors (immobilization, hypoxia, radiation exposure), as well as the introduction of stress implementing agents (adrenaline, cortisol, bee and toad venom) rats. Activity of Na,K-ATPase and the change of EPME washed erythrocytes were examined through 15, 120 min and 24 hours after exposure. Found that at the initial stage (15 min after a stress-exposure) decrease of EPME associated with increased enzyme activity and further increase of EPME takes place on the background of the decrease of activity of Na,K-ATPase in all types of alterations, except the actions toad venom and cortisol. Toad venom and cortisol led to reduced activity of Na,K-ATPase and increase of EPME. PMID:25665408

  20. Something Froggy

    Science.gov (United States)

    Hazel Jobe

    2007-01-01

    Students will learn all about frogs in the story of Frederick the Frog's life cycle. Included are two versions of this interactive story: Primary (K-3) and Junior (4-8). Students can click on a highlighted word for additional information, an audio, and pictures. In the Primary version, students will learn about tadpoles, the differences between frogs and toads, how to make their own pond, how to care for frogs and toads, and take a froggy quiz. The Junior version has a virtual frog, three slide shows on animals and plants that are found in a lily pond, information on Vivaria Projects, a frog's glossary quiz, information about tadpoles, and how to care for frogs and toads. Both include a glossary, printable and interactive word searches, scavenger hunts, egg hunt, matching game, pond mystery search, crossword puzzle, a classification of living things project, and additional Web sites.

  1. Interspecific combat in anurans: a case of Hypsiboas faber (Wied-Neuwied, 1821 (Hylidae and Rhinella pombali (Baldissera-Jr, Caramaschi & Haddad, 2004 (Bufonidae

    Directory of Open Access Journals (Sweden)

    Mário Ribeiro de Moura

    2010-12-01

    Full Text Available We report an interspecific combat involving the tree frog Hypsiboas faber and the toad Rhinella pombali in southeastern Brazil. Since the observation occurred after the beginning of the interaction, either one of the species may have started the fight. In general, intra-specific combats are more common for species in which the male is as large, as or larger than, the female, as observed in Hypsiboas faber. Thus, the male tree frog might have confused the toad with a conspecific opponent. On the other hand, bufonid males can use active searching for females, sometimes clasping other males or objects. Therefore, the toad might have clasped the male tree frog and it was this that provoked the subsequent wrestling.

  2. Tennessee Amphibian Monitoring Program (TAMP)

    Science.gov (United States)

    The Tennessee Wildlife Resources Agency (TWRA) and the Tennessee Department of Environment and Conservation co-sponsor the Tennessee Amphibian Monitoring Program (TAMP). A volunteer-based, multi-agency effort "to assess the current status of amphibians (frogs, toads, and salamanders)" across the state, TAMP is open to all interested participants. The homepage introduces and describes the need for TAMP, and provides a brief list of related sites. Also at the TAMP site are detailed survey protocols (with accompanying color photographs of frogs and toads) and a list of selected references.

  3. Amphibians of the “Cilento e Vallo di Diano” National Park (Campania, Southern Italy: updated check list, distribution and conservation notes

    Directory of Open Access Journals (Sweden)

    Camillo Pignataro

    2010-12-01

    Full Text Available In this study, we present the results of our field and bibliographic survey on the amphibians of the “Cilento and Vallo di Diano” National Park (Southern Italy. Two hundred and thirty three spawning sites (167 original and 66 derived from literature, and 11 amphibian species were found. Reproductive activity was recorded for Salamandra salamandra, Salamandrina terdigitata, Triturus carnifex, Lissotriton italicus, Bufo bufo, Hyla intermedia, Rana italica, Rana dalmatina and Pelophylax synkl. hispanica. The distribution record of many species is widely improved with respect to bibliographic data. Our results also suggested that preservation and restoration of small aquatic sites, in particular of the artificial ones, such as stony wells and drinking-troughs, are fundamental for an appropriate conservation management of amphibians in the “Cilento and Vallo di Diano” National Park.

  4. CRAYFISH PREDATION ON TADPOLES : A COMPARISON BETWEEN A NATIVE (AUSTROPOTAMOBIUS PALLIPES AND AN ALIEN SPECIES (PROCAMBARUS CLARKII.

    Directory of Open Access Journals (Sweden)

    GHERARDI F.

    2001-04-01

    Full Text Available In the laboratory, the motivation and/or ability to prey on anuran larvae (Bufo bufo, Rana kl. esculenta and R. italica were compared between a native European (Austropotamobius pallipes and an alien North American crayfish species (Procambarus clarkii. Both were skilled predators of tadpoles, adopting a sit-and-wait strategy. However, because P. clarkii displayed lower latency times in the presence of one of the three amphibians (Rana kl. esculenta here tested, the hypothesis is raised that invasive crayfish are more opportunistic predators and possibly faster in switching to different prey than those species they are displacing. From a conservation perspective, these preliminary results further emphasise the importance of studies centred on the invasion-displacement dichotomy.

  5. [Chemical constituents of bufadienolides in cinobufacino injection].

    Science.gov (United States)

    Han, Ling-Yu; Si, Nan; Liu, Jun-Qiu; Zhao, Hai-Yu; Yang, Jian; Bian, Bao-Lin; Wang, Hong-Jie

    2014-11-01

    Cinobufacino injection is purified from water extraction of the skin of Bufo bufo gargarizans, which has been widely used for various cancers in clinic with significant anti-tumor effects. Bufadienolides were regarded as the main active constituents of cinobufacino injection in previous reports. In present study, 6 bufadienolides were isolated and purified from Cinobufacino injection. Their structures were identified as 3-epi-?-bufarenogin (1), ?-bufarenogin (2), 3-epi-arenobufagin (3), arenobufagin (4), 3-epi-gamabufotalin (5), and 3-oxo-arenobufagin (6), separately. Among them, 1 and 3 were new compounds, 5 and 6 were new natural products. Compounds 1, 2 and compounds 3, 4 were two pairs configuration isomers at C-3, separately. PMID:25757284

  6. Relação dos anfíbios do Parque Nacional da Lagoa do Peixe, Rio Grande do Sul, Brasil / Amphibians list from Lagoa do Peixe National Park, Rio Grande do Sul, Brazil

    Scientific Electronic Library Online (English)

    Daniel, Loebmann; João P., Vieira.

    2005-06-01

    Full Text Available Este trabalho apresenta uma relação das espécies de anfíbios do Parque Nacional da Lagoa do Peixe. Durante os anos de 2001 e 2002 os anfíbios foram amostrados através de armadilhas de queda, procura visual e identificação através da atividade de vocalização. O estudo cobriu três diferentes ambientes [...] : a) campos e banhados; b) dunas costeiras e c) praia oceânica. Observou-se a presença de 13 espécies distribuídas em três famílias (Bufonidae, Leptodactylidae e Hylidae). As espécies encontradas são típicas da região costeira do Rio Grande do Sul. O número de espécies foi diferente para cada ambiente, sendo maior no ambiente de campos e banhados onde todas as espécies foram encontradas. Nas dunas costeiras foram encontrados sete espécies de anfíbios, sendo Physalaemus biligonigerus (Cope, 1861) e Bufo arenarum Hensel, 1867 as espécies mais abundantes. Bufo arenarum foi a única espécie encontrada na praia oceânica. De acordo com a literatura, esta espécie parece ser a único anuro capaz de suportar este ambiente que sofre forte influência da salinidade, e o usa para se alimentar. Abstract in english This paper reports the first taxonomic list of amphibians from Lagoa do Peixe National Park. During the years 2001 and 2002 we sampled using Pit Fall Traps, visual searching and identification through vocalization activity. The study covered three different habitats: a) plains and swamps; b) coastal [...] dunes and c) open beach. We observed 13 species into three families (Bufonidae, Leptodactylidae and Hylidae). All species were found along all coastal environment of Rio Grande do Sul. The number of species was different for each environment, being greater in plains and swamps, where all species were found. On the coastal dunes we found seven species of amphibians, being Physalaemus biligonigerus (Cope, 1861) and Bufo arenarum Hensel, 1867 the most abundant. Bufo arenarum was the unique specie that was found in the beach. According to literature, this species seems to be the only anuran able to support this environment which has strong influence of salinity, using it for feeding.

  7. Relação dos anfíbios do Parque Nacional da Lagoa do Peixe, Rio Grande do Sul, Brasil Amphibians list from Lagoa do Peixe National Park, Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Daniel Loebmann

    2005-06-01

    Full Text Available Este trabalho apresenta uma relação das espécies de anfíbios do Parque Nacional da Lagoa do Peixe. Durante os anos de 2001 e 2002 os anfíbios foram amostrados através de armadilhas de queda, procura visual e identificação através da atividade de vocalização. O estudo cobriu três diferentes ambientes: a campos e banhados; b dunas costeiras e c praia oceânica. Observou-se a presença de 13 espécies distribuídas em três famílias (Bufonidae, Leptodactylidae e Hylidae. As espécies encontradas são típicas da região costeira do Rio Grande do Sul. O número de espécies foi diferente para cada ambiente, sendo maior no ambiente de campos e banhados onde todas as espécies foram encontradas. Nas dunas costeiras foram encontrados sete espécies de anfíbios, sendo Physalaemus biligonigerus (Cope, 1861 e Bufo arenarum Hensel, 1867 as espécies mais abundantes. Bufo arenarum foi a única espécie encontrada na praia oceânica. De acordo com a literatura, esta espécie parece ser a único anuro capaz de suportar este ambiente que sofre forte influência da salinidade, e o usa para se alimentar.This paper reports the first taxonomic list of amphibians from Lagoa do Peixe National Park. During the years 2001 and 2002 we sampled using Pit Fall Traps, visual searching and identification through vocalization activity. The study covered three different habitats: a plains and swamps; b coastal dunes and c open beach. We observed 13 species into three families (Bufonidae, Leptodactylidae and Hylidae. All species were found along all coastal environment of Rio Grande do Sul. The number of species was different for each environment, being greater in plains and swamps, where all species were found. On the coastal dunes we found seven species of amphibians, being Physalaemus biligonigerus (Cope, 1861 and Bufo arenarum Hensel, 1867 the most abundant. Bufo arenarum was the unique specie that was found in the beach. According to literature, this species seems to be the only anuran able to support this environment which has strong influence of salinity, using it for feeding.

  8. Diet of the colubrid snake, Thamnodynastes strigatus (Günther, 1858) from Paraná State, Brazil, with field notes on anuran predation Dieta da Serpente Colubridae, Thammodynastesstrigatus (Günther, 1858), no Estado do Paraná, Brasil, com notas de predação sobre anuros na natureza

    OpenAIRE

    P. S. BERNARDE; MOURA-LEITE J. C.; Machado, R. A.; KOKOBUM M. N. C.

    2000-01-01

    Dissection of 44 specimens of the colubrid snake Thamnodynastes strigatus (Serpentes: Colubridae) provided data on food habits. Prey items include frogs (71.4% of the sample), rodents (14.3%), fishes (10.7%), and lizards (3.6%). The most of the anuran species recorded (Bufo sp., Leptodactylus sp., Physalaemus cuvieri and Scinax fuscovarius) are ground dwellers or call at the water level. Field observations provided information on the feeding behavior.São apresentados dados da dieta de Thamno...

  9. Diet of the colubrid snake, Thamnodynastes strigatus (Günther, 1858) from Paraná State, Brazil, with field notes on anuran predation

    OpenAIRE

    P. S. BERNARDE; MOURA-LEITE J. C.; Machado, R. A.; KOKOBUM M. N. C.

    2000-01-01

    Dissection of 44 specimens of the colubrid snake Thamnodynastes strigatus (Serpentes: Colubridae) provided data on food habits. Prey items include frogs (71.4% of the sample), rodents (14.3%), fishes (10.7%), and lizards (3.6%). The most of the anuran species recorded (Bufo sp., Leptodactylus sp., Physalaemus cuvieri and Scinax fuscovarius) are ground dwellers or call at the water level. Field observations provided information on the feeding behavior.

  10. Diet of the colubrid snake, Thamnodynastes strigatus (Günther, 1858 from Paraná State, Brazil, with field notes on anuran predation

    Directory of Open Access Journals (Sweden)

    BERNARDE P. S.

    2000-01-01

    Full Text Available Dissection of 44 specimens of the colubrid snake Thamnodynastes strigatus (Serpentes: Colubridae provided data on food habits. Prey items include frogs (71.4% of the sample, rodents (14.3%, fishes (10.7%, and lizards (3.6%. The most of the anuran species recorded (Bufo sp., Leptodactylus sp., Physalaemus cuvieri and Scinax fuscovarius are ground dwellers or call at the water level. Field observations provided information on the feeding behavior.

  11. Contributions to knowledge regarding the geographical distribution of the herpetofauna of Dobrudja, Romania

    Directory of Open Access Journals (Sweden)

    Horia V. BOGDAN

    2006-12-01

    Full Text Available In Dobrudja we encountered 10 species of amphibians (Triturus dobrogicus, Bombina bombina, Hyla arborea, Pelobates fuscus, Pelobates syriacus, Bufo bufo, Bufo viridis, Rana dalmatina, Rana ridibunda, Rana lessonae, 16 species of reptiles (Emys orbicularis, Testudo graeca, Ablepharus kitaibelli, Lacerta agilis, Lacerta viridis, Lacerta trilineata, Podarcis taurica, Podarcis muralis, Eremias arguta, Coronella austriaca, Zamensis longissimus, Elaphe quatuorlineata, Dolichophis caspius, Natrix natrix, Natrix tessellata, Vipera ammodytes and also Rana kl. esculenta populations. Some species of amphibians (Pelobates fuscus, Pelobates syriacus that were only previously known inform the lower regions of the Danube’s meadow and in the vicinity of the Black Sea, were recorded in the high areas of northern Dobrudja. Also here, all three forms of the green frogs’ complex documented for Romania have been encountered, but Rana lessonae and Rana esculenta are very rare, being found only in the north. The central sectors of Dobrudja are severely impacted by human activities, almost completely cleared as a result of agriculture and showed very low number of herpetofauna species as being present. The most important areas for the herpetofauna are the northern and south-western regions.

  12. Assessing the Influence of the Automobile Traffic on the Amphibians and Reptiles in the Buffer Zone of Biosphere Reserve “Srebarna” (NE Bulgaria

    Directory of Open Access Journals (Sweden)

    Ivelin A. Mollov

    2013-12-01

    Full Text Available Currently the problem of the effects of the road network and traffic on the amphibians and reptiles in Bulgaria is poorly studied. During the period March 2002 - March 2004 in the Buffer Zone of Biosphere Reserve "Srebarna" (NE Bulgaria were built two anti-fire roads from the eastern and western side of the lake in area of grasslands of semi-steppe type, typical for north-eastern Bulgaria. The aim of the constructed roads is to provide access for fire vehicles to areas in and around the reserve. The current study aims to provide data on the impact of road traffic and the newly constructed road network and another previously existing road on the amphibians and reptiles inhabiting the buffer zone of the biosphere reserve "Srebarna". For the entire period of study in the three studied road sections a total of 15 dead specimens of amphibians belonging to 4 species (Bombina bombina, Hyla arborea, Bufo bufo, Bufo viridis and 70 dead specimens of reptiles belonging to 8 species (Emys orbicularis, Ablepharus kitaibelii, Lacerta viridis, Podarcis tauricus, Podarcis muralis, Natrix natrix, Coronella austriaca and Dolichophis caspius were recorded. Several “hot spots”, where most cadavers were recorded are well described and possible conservation measures are discussed.

  13. Preliminary data regarding the distribution and status of the herpetofauna in Ia?i County (Romania

    Directory of Open Access Journals (Sweden)

    Alexandru STRUGARIU

    2008-11-01

    Full Text Available This paper presents the results of a study conducted in Ia?i County, Romania, an area for which data regarding the distribution of the herpetofauna has previously remained incomplete. Thirteen species of amphibians (Salamandra salamandra, Lissotriton vulgaris, Triturus cristatus, Pelobates fuscus, Hyla arborea, Bombina bombina, Bombina variegata, Bufo bufo, Bufo viridis, Pelophylax ridibundus, Pelophylax lessonae, Rana dalmatina and Rana temporaria, nine reptile species (Emys orbicularis, Anguis fragilis, Lacerta agilis, Lacerta viridis, Natrix natrix, Coronella austriaca, Zamenis longissimus, Vipera berus and Vipera ursiniiand hybrids between B. bombina and B. variegata and between P. ridibundus and P. lessonae (Pelophylax kl. esculentus were recorded in the 62 investigated localities in Ia?i County. Salamandra salamandra is recorded for the first time in the area, east of the Siret river, being situated at its eastern distribution limit for Europe. Among the most important results of our study is the identification of a new locality for one of the rarest European reptiles, Vipera ursinii. One amphibian (Lissotriton montandoni and one reptile (Elaphe sauromates have previously been recorded in our study area but we were unable to reconfirm their presence.

  14. THE HERPETOFAUNA OF THE NATURAL RESERVATION FROM THE INFERIOR COURSE OF THE TUR RIVER AND ITS SURROUNDING AREAS

    Directory of Open Access Journals (Sweden)

    Severus D. COVACIU-MARCOV

    2008-01-01

    Full Text Available In the studied area we encountered 14 species of amphibians (Salamandra salamandra, Triturus vulgaris, Triturus cristatus, Triturus dobrogicus, Bombina bombina, Bombina variegata, Pelobates fuscus, Hyla arborea, Bufo bufo, Bufo viridis, Rana ridibunda, Rana lessonae, Rana dalmatina, Rana arvalis and 9 species of reptiles (Emys orbicularis, Lacerta agilis, Lacerta viridis, Zootoca vivipara, Anguis fragilis, Natrix natrix, Coronella austriaca, Elaphe longissima and Vipera berus. Hybrids between Triturus cristatus and Triturus dobrogicus, Bombina bombina and Bombina variegata and Rana kl. esculenta are also present in this region. The herpetofauna of this reservation from the inferior course of the Tur River stands out through the glacier relicts that live here, in the woody swamps from the plains (R. arvalis, Z. vivipara and V. berus. Population of Salamandra salamandra and Bombina variegata can be found here at altitudes of no more than 140 m. In this reservation, all the three forms of the Rana green complex that live in Romania are present. The most important sectors of the reservation, from what the herpetofauna is concerned, are the afforested areas. These shelter most of the species and the biggest population of the protected species. The results of our study show the necessity to include into the reservation the forests from Livada.

  15. The herpethofauna from the Teuz River hydrographic basin (Arad County, Romania

    Directory of Open Access Journals (Sweden)

    H. Bogdan

    2006-01-01

    Full Text Available In the Teuz River hydrographic basin from the western part of Romania we encountered 15 species of amphibians (Salamandra salamandra, Triturus vulgaris, Triturus cristatus, Triturus dobrogicus, Triturus alpestris, Bombina bombina, Bombina variegata, Bufo bufo, Bufo viridis, Hyla arborea, Pelobates fuscus, Rana ridibunda, Rana lessonae, Rana dalmatina, Rana temporaria, 8 species of reptiles (Emys orbicularis, Lacerta agilis, Lacerta viridis, Podarcis muralis, Anguis fragilis, Natrix natrix, Coronella austriaca, Vipera berus and hybrids between Triturus cristatus and Triturus dobrogicus, Bombina bombina and Bombina variegata plus some Rana kl. esculenta. Rana lessonae is signaled for the first time ever in Arad County, the Igne?ti area representing hence forth the farthest southern limit of the species’ spreading in the western Romania. Vipera berus comes down to 200 m in altitude in the wetlands from Igne?ti. Around the Hills of M?r?u? and Teuz, Triturus alpestris comes down to 200 m as well, reaching in the Craiva – ?iad region the lowest altitude that it has ever been identified at in Romania: 150m.

  16. Final report on effects of environmental radiation of Kori nuclear power plant on human population

    International Nuclear Information System (INIS)

    In order to clarify and protect the effects of environmental radiation according to the operation of Kori nuclear power plant on the human population, the base line survey for the human monitoring, human life habits, expected individual exposure dose, frequencies of chromosomal aberration, gene frequencies and karyotypes in amphibia, fauna, and radiation sensitivities in microorganisms which have been living around the power plant site were carried out. Kilchonri population which took for the human monitoring lie within a 2 km distance from the power plant site. Human monitoring, house and food characteristics, individual experience of x-ray exposures, human chromosome analysis and fauna were surveyed and expressed in numerical tables. Chromosome number obtained from the amphibia which were collected around the power plant area was as follows: Kaloula borealis 2N=30, Rana amurensis 2N=26, Rana dybouskii 2N=24, Rana rugosa 2N=26, Rana nigromaculata 2N=26, Rana plancyi 2N=26, Bombina orientalis 2N=24, Hyla arborea 2N=24, Bufo stejnegeri 2N=22, Bufo bufo 2N=22. (author)

  17. Three dimensional Conformal Field Theories from Sasakian seven-manifolds

    CERN Document Server

    Fabbri, D

    1999-01-01

    We present the construction of the candidate conformal field theories dual to$AdS_4$ non-maximally supersymmetric compactifications of 11D supergravity. Wecompare the spectra of the two theories and discuss the realization of thebaryonic symmetries. Finally we comment on the presence in the spectrum of longmultiplets with rational energies, trying to explain their existence.

  18. "mina usun sõna..." : [luuletused] / Maarja Kangro, Mart Kangur, Lauri Kitsnik jt

    Index Scriptorium Estoniae

    2007-01-01

    Sisu: "mina usun sõna..." ; Tüdruk heitis mulle silma (Silmapartii) ; "Helista siis mulle. Hoolimata sellest, mis kell ma täna magama..." ; Tärkab ; Toad ; "Tee sees on augud. Maa sees on augud..." ; "Puuk on perses. Ai-ai, valus on..." ; Päärätik ; Pliidikütt ; "Ukrainlannast põetaja..." ; Stereonurr ; "Luuletused..."

  19. Pääsupesad 1-5 : [luuletused] / Saila Susiluoto ; tõlkinud Hasso Krull

    Index Scriptorium Estoniae

    Susiluoto, Saila

    2004-01-01

    Sisu: Pääsupesad:1-5 ; Viis muinasjuttu Espoo ridamajadest: 1-5 ; Tüdrukumuinasjutt ; Muinasjutt maast ; Naiste tualettruum ; Relvakamber ; Koridoriaken öösel ; Õe ja venna toast viib trepp vanasse kartulikeldrisse, nüüd moosikeldrisse ; Varisev tuba mehaanilise luigega ; Toas kasvab palavikupuu, toast läbi ; Lühike trepp ; Sinise magamistoa rõdu ; Vee toad. Eluloolisi andmeid autori kohta lk. 278

  20. Microelectronic neural bridge for signal regeneration and function rebuilding over two separate nerves

    International Nuclear Information System (INIS)

    According to the feature of neural signals, a micro-electronic neural bridge (MENB) has been designed. It consists of two electrode arrays for neural signal detection and functional electrical stimulation (FES), and a microelectronic circuit for signal amplifying, processing, and FES driving. The core of the system is realized in 0.5-?m CMOS technology and used in animal experiments. A special experimental strategy has been designed to demonstrate the feasibility of the system. With the help of the MENB, the withdrawal reflex function of the left/right leg of one spinal toad has been rebuilt in the corresponding leg of another spinal toad. According to the coherence analysis between the source and regenerated neural signals, the controlled spinal toad's sciatic nerve signal is delayed by 0.72 ms in relation to the sciatic nerve signal of the source spinal toad and the cross-correlation function reaches a value of 0.73. This shows that the regenerated signal is correlated with the source sciatic signal significantly and the neural activities involved in reflex function have been regenerated. The experiment demonstrates that the MENB is useful in rebuilding the neural function between nerves of different bodies. (semiconductor integrated circuits)

  1. Junior Frogs

    Science.gov (United States)

    This Java applet game allows children to think strategically in an engaging context: the goal is for the two frogs and two toads to change places on the lily pads. The challenge is to do this in as few slides and jumps as possible. Students will need to work very systematically and may also want to develop their own recording system.

  2. Ermitaazh läheb Amsterdami / Rael Artel

    Index Scriptorium Estoniae

    Artel, Rael, 1980-

    2003-01-01

    Peterburi Ermitaazhi filiaali avamisest Amstelhofis Hollandis. Avanäitusel veebruaris 2004 saab tutvuda ligi sajakonna Musta mere regioonist pärit antiikkreeka kuldehtega. Filiaali rajamise II faasist. Ermitaazhil on toad Somerset House'is Londonis, kollektsioonide jagamise leping Guggenheimiga New Yorgis ja Kunsthistorisches Museumiga Viinis

  3. Leaping Lizards And Learning. In the Curriculum: Science

    Science.gov (United States)

    Petersen, Diane; Nelson, Cathi

    2004-01-01

    In the broad fields that stretch toward the horizon in the Columbia Basin region of Washington state, the land is just right for at least two purposes: growing dryland wheat and providing habitat for shorthorned lizards, also known as horny toads. Our elementary school, enrolling 150 children from this rural farming community, has become a hub for…

  4. A Field Guide to the Reptiles and Amphibians of Coastal Southern California

    Science.gov (United States)

    Robert Fisher

    This guide contains the scientific name, common name, size, adult and juvenile characteristics, dimorphism, similar species, and additional notes (behavior, distribution) for species of reptiles and amphibians found in the coastal southern California region. These include frogs, toads, salamanders, lizards, turtles, and snakes, both native and introduced species. The guide also discusses species' habitats, such as sage scrub, grasslands, chaparral, riparian environments, and woodlands.

  5. Incorporating Amphibian Malformations into Inquiry-Based Learning

    Science.gov (United States)

    Talley, Brooke L.

    2007-01-01

    Amphibians, a class of vertebrates consisting of frogs and toads, salamanders, and caecilians, are excellent organisms for middle school science students to study because of their ecological significance. Because they exchange oxygen and carbon dioxide through their skin, amphibians absorb any chemicals or substances present in their immediate…

  6. Endemic predators, invasive prey and native diversity.

    Science.gov (United States)

    Wanger, Thomas C; Wielgoss, Arno C; Motzke, Iris; Clough, Yann; Brook, Barry W; Sodhi, Navjot S; Tscharntke, Teja

    2011-03-01

    Interactions between native diversity and invasive species can be more complex than is currently understood. Invasive ant species often substantially reduce diversity in the native ants diversity that act as natural control agents for pest insects. In Indonesia (on the island of Sulawesi), the third largest cacao producer worldwide, we show that a predatory endemic toad (Ingerophrynus celebensis) controls invasive ant (Anoplolepis gracilipes) abundance, and positively affects native ant diversity. We call this the invasive-naivety effect (an opposite of enemy release), whereby alien species may not harbour anti-predatory defences against a novel native predator. A positive effect of the toads on native ants may facilitate their predation on insect vectors of cacao diseases. Hence, toads may increase crop yield, but further research is needed on this aspect. Ironically, amphibians are globally the most threatened vertebrate class and are strongly impacted by the conversion of rainforest to cacao plantations in Sulawesi. It is, therefore, crucial to manage cacao plantations to maintain these endemic toads, as they may provide critical ecosystem services, such as invasion resistance and preservation of native insect diversity. PMID:20826488

  7. Atlas de distribución y estado de conservación de los Anfibios de la Comunidad de Madrid

    Directory of Open Access Journals (Sweden)

    Martínez-Solano, I.

    2006-05-01

    Full Text Available Successful management and conservation planning depend upon the availability, integration and updating of information provided by different disciplines. This paper compiles relevant information for the conservation of amphibians in Comunidad de Madrid (Spain. We obtained chorological information from 1384 sampling localities throughout the region of Madrid, and reviewed relevant scientific literature for the management of amphibian populations in this area. We found at least one amphibian species in 70,3% of sampled localities. Results are illustrated in distribution maps of all 18 species found: Salamandra salamandra, Pleurodeles waltl, Mesotriton alpestris, Lissotriton boscai, Triturus marmoratus, Triturus pygmaeus, Alytes obstetricans, Alytes cisternasii, Discoglossus galganoi, Discoglossus jeanneae, Pelobates cultripes, Pelodytes punctatus, Hyla arborea, Hyla meridionalis, Bufo bufo, Bufo calamita, Rana iberica and Rana perezi. Distribution maps are presented in five-kilometer side UTM grids cells. We compare and integrate our results with previous studies and outline groups of populations representing independent management units, for which we propose risk categories according to the criteria established by the International Union for the Conservation of Nature (IUCN at the regional level. Finally, we point out the main threats for the survival of amphibian populations and discuss possible actions to improve their conservation status.

    La planificación de estrategias de gestión y conservación eficaces depende de la disponibilidad, integración y actualización de información procedente de diversas disciplinas. En este trabajo se recopila información relevante para la conservación de los anfibios de la Comunidad de Madrid. Hemos obtenido información corológica de un total de 1384 puntos de muestreo repartidos por toda la geografía madrileña y revisado la literatura científica de interés para la gestión de las poblaciones de anfibios en esta región. En el 70,3% de los puntos muestreados se ha encontrado al menos una especie de anfibio. Los resultados se ilustran mediante mapas de distribución de cada una de las 18 especies encontradas: Salamandra salamandra, Pleurodeles waltl, Mesotriton alpestris, Lissotriton boscai, Triturus marmoratus, Triturus pygmaeus, Alytes obstetricans, Alytes cisternasii, Discoglossus galganoi, Discoglossus jeanneae, Pelobates cultripes, Pelodytes punctatus, Hyla arborea, Hyla meridionalis, Bufo bufo, Bufo calamita, Rana iberica y Rana perezi. Los mapas de distribución se presentan en cuadrículas UTM de 5x5 km. Se comparan e integran los resultados obtenidos con los de estudios anteriores y se delimitan grupos de poblaciones que representan unidades independientes de gestión, para los cuales se proponen categorías de amenaza según los criterios establecidos por la Unión Internacional para la Conservación de la Naturaleza (IUCN a nivel regional. Finalmente, se señalan las principales amenazas para la supervivencia de las poblaciones de anfibios madrileños y se discuten posibles actuaciones para mejorar su estado de conservación.

  8. Histopathologic changes in liver and kidney tissues induced by carbaryl in Bufotes variabilis (Anura: Bufonidae).

    Science.gov (United States)

    Çak?c?, Özlem

    2015-03-01

    The purpose of this work was to investigate for the first time histopathologic effects of carbaryl in liver and kidney tissues of Bufotes variabilis. After 96h following exposure to carbaryl (low dose: 0.05, medium dose: 0.1 and high dose: 0.2mg/g), the toads were euthanized and dissected. In liver tissue, vacuolization in hepatocytes, necrosis, mononuclear cell infiltration, an increase in melanomacrophage number, enlargement of sinusoids, hemorrhage and congestion were determined in exposed toads. In kidney tissue, mononuclear cell infiltration, hypertrophied Bowman's capsule cells, deformation, vacuolization, karyolysis and necrosis of renal tubule epithelium, brush border destruction, glomerular shrinkage, hemorrhage and fibrosis were observed in carbaryl-treated groups. According to this investigation, carbaryl caused histopathologic damages in liver and kidney tissues of B. variabilis. PMID:25573057

  9. Amphibian monitoring in the Atchafalaya Basin

    Science.gov (United States)

    Waddle, Hardin

    2011-01-01

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

  10. Is Phosphorylation of the ?1 Subunit at Ser-16 Involved in the Control of Na,K-ATPase Activity by Phorbol Ester–activated Protein Kinase C?

    OpenAIRE

    Fe?raille, Eric; Be?guin, Pascal; Carranza, Maria-luisa; Gonin, Sandrine; Rousselot, Martine; Martin, Pierre-yves; Favre, Herve?; Geering, Ka?thi

    2000-01-01

    The ?1 subunit of Na,K-ATPase is phosphorylated at Ser-16 by phorbol ester-sensitive protein kinase(s) C (PKC). The role of Ser-16 phosphorylation was analyzed in COS-7 cells stably expressing wild-type or mutant (T15A/S16A and S16D-E) ouabain-resistant Bufo ?1 subunits. In cells incubated at 37°C, phorbol 12,13-dibutyrate (PDBu) inhibited the transport activity and decreased the cell surface expression of wild-type and mutant Na,K-pumps equally (?20–30%). T...

  11. Evidence for a proenkephalin-like precursor in amphibian brain.

    OpenAIRE

    Kilpatrick, D. L.; Howells, R. D.; Lahm, H. W.; Udenfriend, S.

    1983-01-01

    The mammalian proenkephalin-derived peptides [Leu]enkephalin, [Met]enkephalin, and [Met]enkephalin-Arg6-Phe7 were identified in acid extracts of the brain of Bufo marinus by using reversed-phase HPLC and specific radioimmunoassays. [Met]Enkephalin was the predominant opioid peptide present (270 pmol/g). In contrast, the octapeptide [Met]enkephalin-Arg6-Gly7-Leu8, which is also derived from mammalian proenkephalin, was not detected. The ratio of free [Met]enkephalin to [Met]enkephalin-Arg6-Phe...

  12. The nerve protection and in vivo therapeutic effect of Acalypha indica extract in frogs

    OpenAIRE

    Purwaningsih, Ernie H.; Nurhadi Ibrahim; Hamdani Zain (alm)

    2010-01-01

    Aim To demonstrate nerve protection and/or treatment effect of Acalypha indica Linn. extract on nerve paralysis induced by subcutaneus injection of pancuronium bromide on frog’s back.Methods The study was performed on sixty frogs (Bufo melanostictus Schneider) that divided into two groups, i.e. the neuro-protection and neuro-therapy group. Each group was divided further into 6 sub-treatment groups: negative control group treated by water and positive control group treated by piracetam, t...

  13. Electrophoretic pattern of blood serum proteins of some of the vertebrates of Pakistan

    International Nuclear Information System (INIS)

    The electrophoretic pattern of blood serum proteins of some of the common fishes e.g. Catla catla, Cirrhina mrigala, Channa punctatus, Channa marulius, Wallago attu, Heterop-neustes fossilis; amphibia e.g., Rana tigrina, Rana cyanophlyctis, Bufo melanostictus; reptiles e.g. Varanus bengalensis, Uromastix hardwickii; birds e.g. Columba livia, Gallus domesticus, Passer domestica, Anas platyrhynchos; and mammals e.g. Homo sapiens, Mus musculus, Lepus cuniculus have been described. The mobility of proteins of blood sera has been studied over cellulose acetate paper and then a comparative pattern analysed

  14. Chemical Evaluation of the Nutrient Composition of Some Unconventional Animal Protein Sources

    OpenAIRE

    Ojewola, G. S.; Udom, S. F.

    2005-01-01

    A trial was conducted to assess the nutrient composition of some novel feed ingredients so as to enhance livestock development and human protein intake. Ten (10) unconventional protein sources which include fish, crayfish, frog, shrimps, crabs, squilla, toads and grasshopper were harvested, processed and analyzed for their proximate and mineral (macro) composition using internationally established procedures. The results showed that the samples had percent crude protein that ranged fro...

  15. Nonlethal injury caused by an invasive alien predator and its consequences for an anuran tadpole

    OpenAIRE

    Nunes, Ana L.; Cruz, Mari?a J.; Tejedo, Miguel; Laurila, Anssi; Rebelo, Rui

    2010-01-01

    Nonlethal tail injury resulting from unsuccessful predation attempts is common in anuran larvae and can potentially induce significant fitness costs in terms of survival and growth. We tested the hypotheses that the alien red swamp crayfish, Procambarus clarkii, is an important inducer of tail injury in tadpoles of the Iberian spadefoot toad, Pelobates cultripes, and that tail damage can have important consequences for the tadpoles' life history and morphology. This was investigated by first ...

  16. Advertisement call of Rhinella inopina Vaz-Silva, Valdujo & Pombal, 2012 (Anura: Bufonidae) from the type-locality, northeastern Goiás State, Central Brazil.

    Science.gov (United States)

    De Andrade, Sheila Pereira; Rocha, Cezar Filho; Victor-Junior, Edmar Pereira; Vaz-Silva, Wilian

    2015-01-01

    The Rhinella crucifer species group currently comprises six species of toads: R. abei (Baldissera, Caramaschi & Haddad, 2004); R. crucifer (Wied-Neuwied, 1821); R. henseli (A. Lutz, 1934); R. ornata (Spix, 1824); R. pombali (Baldissera, Caramaschi & Haddad, 2004); and, R. inopina Vaz-Silva, Valdujo & Pombal, 2012. Recent genetic studies suggest five species in the R. crucifer species group and show evidence of hybridization between R. crucifer and R. ornata (Thomé et al. 2012). PMID:25781840

  17. Estimating Occupancy Dynamics in an Anuran Assemblage from Louisiana, USA

    Science.gov (United States)

    Walls, Susan C.; Waddle, J. Hardin; Dorazio, Robert M.

    2011-01-01

    Effective monitoring programs are designed to track changes in the distribution, occurrence, and abundance of species. We developed an extension of Royle and Kéry's (2007) single species model to estimate simultaneously temporal changes in probabilities of detection, occupancy, colonization, extinction, and species turnover using data on calling anuran amphibians, collected from 2002 to 2006 in the Lower Mississippi Alluvial Valley of Louisiana, USA. During our 5-year study, estimates of occurrence probabilities declined for all 12 species detected. These declines occurred primarily in conjunction with variation in estimates of local extinction probabilities (cajun chorus frog [Pseudacris fouquettei], spring peeper [P. crucifer], northern cricket frog [Acris crepitans], Cope's gray treefrog [Hyla chrysoscelis], green treefrog [H. cinerea], squirrel treefrog [H. squirella], southern leopard frog [Lithobates sphenocephalus], bronze frog [L. clamitans], American bullfrog [L. catesbeianus], and Fowler's toad [Anaxyrus fowleri]). For 2 species (eastern narrowmouthed toad [Gastrophryne carolinensis] and Gulf Coast toad [Incilius nebulifer]), declines in occupancy appeared to be a consequence of both increased local extinction and decreased colonization events. The eastern narrow-mouthed toad experienced a 2.5-fold increase in estimates of occupancy in 2004, possibly because of the high amount of rainfall received during that year, along with a decrease in extinction and increase in colonization of new sites between 2003 and 2004. Our model can be incorporated into monitoring programs to estimate simultaneously the occupancy dynamics for multiple species that show similar responses to ecological conditions. It will likely be an important asset for those monitoring programs that employ the same methods to sample assemblages of ecologically similar species, including those that are rare. By combining information from multiple species to decrease the variance on estimates of individual species, our results are advantageous compared to single-species models. This feature enables managers and researchers to use an entire community, rather than just one species, as an ecological indicator in monitoring programs.

  18. From metamorphosis to maturity in complex life cycles: equal performance of different juvenile life history pathways

    OpenAIRE

    Schmidt, B. R.; Ho?dl, W.; Schaub, Michael P.

    2012-01-01

    Performance in one stage of a complex life cycle may affect performance in the subsequent stage. Animals that start a new stage at a smaller size than conspecifics may either always remain smaller or they may be able to “catch up” through plasticity, usually elevated growth rates. We study how size at and date of metamorphosis affected subsequent performance in the terrestrial juvenile stage and lifetime fitness of spadefoot toads (Pelobates fuscus). We analyzed capture–recapture data o...

  19. Expression pattern of three-finger toxin and phospholipase A2 genes in the venom glands of two sea snakes, Lapemis curtus and Acalyptophis peronii: comparison of evolution of these toxins in land snakes, sea kraits and sea snakes

    OpenAIRE

    Fry Bryan G; Bickford David; Pahari Susanta; Kini R Manjunatha

    2007-01-01

    Abstract Background Snake venom composition varies widely both among closely related species and within the same species, based on ecological variables. In terrestrial snakes, such variation has been proposed to be due to snakes' diet. Land snakes target various prey species including insects (arthropods), lizards (reptiles), frogs and toads (amphibians), birds (aves), and rodents (mammals), whereas sea snakes target a single vertebrate class (fishes) and often specialize on specific types of...

  20. The Puzzles Of the Prokineticin 2 Pathway in Human Reproduction

    OpenAIRE

    Balasubramanian, Ravikumar; Plummer, Lacey; Sidis, Yisrael; Pitteloud, Nelly; Cecilia, Martin; ZHOU, QUN-YONG; Crowley, William F.

    2011-01-01

    The Prokineticins, 1 (PROK1) and prokineticin 2 (PROK2), are two closely related proteins that were identified as the mammalian homologues of their two amphibian homologues, mamba intestinal toxin (MIT-1) and Bv8. MIT-1 was initially identified as a non-toxic constituent in the venom of the black mamba snake (Dendroaspis polylepis) (Joubert and Strydom 1980) while Bv8 was identified in the skin secretion of the toad, Bombina variegate (Mollay, Wechselberger et al. 1999). All three homologues ...

  1. Canadian Amphibian and Reptile Conservation Network (CARCN) = Reseau Canadien de Conservation des Amphibiens et des Reptiles (RCCAR)

    Science.gov (United States)

    The Canadian Amphibian and Reptile Conservation Network (CARCN) provides information on the biology and conservation of Canada's frogs, toads, and salamanders. Four sections form the substance of the site: Amphibian Biology, Key to Canadian Amphibians, Tour of Canadian Amphibians, and Amphibian Decline Issues. Descriptive information includes frog calls and distribution maps, as well as photographs of species. Additional sections describe CARCN and challenge users to test their knowledge via The Great Canadian Amphibian & Reptile Quiz.

  2. Consequences of Physical Disturbance by Tadpoles and Snails on Chironomid Larvae

    OpenAIRE

    Gargi Pal; Gautam Aditya; Niladri Hazra

    2014-01-01

    Indirect interactions among community members impact on organisms. The effects of two snails, banded pond snail, Bellamya bengalensis (Lamarck), and Red-rimmed melania, Melanoides tuberculata (Müller), and tadpoles of Asian common toad, Duttaphrynus melanostictus (Schneider), on nonbiting midge larvae, Chironomus striatipennis Kieffer, were observed in experimental microcosm. Decrease in tube number and tube length of midge larvae was observed compared to control condition due to introductio...

  3. The Otter (Lutra lutra) in Central Finland

    OpenAIRE

    Risto Sulkava

    1994-01-01

    The otter population on the upper tributaries of the Kokemäenjoki-river system was carefully surveyed by snow-tracking in 1985 - 1993. The otter population in the study area increased in the last eight years. All otters appear to be born in summer. The otters travel in their large home range all year round. Traffic (cars), fish traps and fish hatcheries caused the most of otter deaths. The diet is 60% small fish, with frogs and toads being seasonally important.

  4. Mechanism of Action of the Egyptian Garlic "Allium sativum" on Excitable Tissues

    OpenAIRE

    Aida Ahmed Hussein

    2003-01-01

    Garlic has been used for millennia in the traditional medicine practice of many cultures to treat cardiovascular and others disorders. In this study, mechanism of action of garlic on several excitable membranes have been discussed. three groups of isolated toads hearts were used to investigate the effect as well as the mechanism of garlic solution (4 g ml-1) on the physiological properties of the myocardium through the electrocardiogram (ECG) recordings. A significant decrease of the heart ra...

  5. Endemic predators, invasive prey and native diversity

    OpenAIRE

    Wanger, Thomas C.; Wielgoss, Arno C.; Motzke, Iris; Clough, Yann; Brook, Barry W.; Sodhi, Navjot S.; Tscharntke, Teja

    2010-01-01

    Interactions between native diversity and invasive species can be more complex than is currently understood. Invasive ant species often substantially reduce diversity in the native ants diversity that act as natural control agents for pest insects. In Indonesia (on the island of Sulawesi), the third largest cacao producer worldwide, we show that a predatory endemic toad (Ingerophrynus celebensis) controls invasive ant (Anoplolepis gracilipes) abundance, and positively affects native ant diver...

  6. Hemoparasites of the genus Trypanosoma (Kinetoplastida: Trypanosomatidae) and hemogregarines in Anurans of the São Paulo and Mato Grosso do Sul States - Brazil

    OpenAIRE

    Denise D.M. Leal; Lucia H. O'dwyer; Vitor C. Ribeiro; Reinaldo J. Silva; Vanda L. Ferreira; Rozangela B. Rodrigues

    2009-01-01

    Wild animals are exposed to numerous pathogens, including hemoparasites. The Trypanosoma and hemogregarinegroup are frequently reported as parasites in anurans (frogs, tree frogs and toads). The identification of these hemoparasites is usually made through stage observation of their morphology in the peripheral blood of the host. There areno studies, however, based on the biological cycle of these hemoparasites. The objective of the present study was toevaluate the presence of hemogregarines ...

  7. Solar Radiation Alters Toxicity of Carbofuran: Evidence from Empirical Trials with Duttaphyrnus melanostictus

    OpenAIRE

    Wijesinghe, M. R.; Jayatillake, B. A. D. M. C.; Ratnassoriya, W. D.

    2011-01-01

    In the present study we investigated the potential of natural solar radiation to alter the toxicity of a commonly used carbamate pesticide, carbofuran, on tadpoles of the Common Asian Toad Duttaphrynus melanostictus. A single exposure trial was conducted over 96 hrs with three concentrations (150, 250 and 500 µgl-1) of photo-irradiated and non-irradiated carbofuran. Results show that photo-irradiation markedly reduced the toxicity of carbofuran as evident by its effects on three end points, ...

  8. Sequential assessment of prey through the use of multiple sensory cues by an eavesdropping bat

    Science.gov (United States)

    Page, Rachel A.; Schnelle, Tanja; Kalko, Elisabeth K. V.; Bunge, Thomas; Bernal, Ximena E.

    2012-06-01

    Predators are often confronted with a broad diversity of potential prey. They rely on cues associated with prey quality and palatability to optimize their hunting success and to avoid consuming toxic prey. Here, we investigate a predator's ability to assess prey cues during capture, handling, and consumption when confronted with conflicting information about prey quality. We used advertisement calls of a preferred prey item (the túngara frog) to attract fringe-lipped bats, Trachops cirrhosus, then offered palatable, poisonous, and chemically manipulated anurans as prey. Advertisement calls elicited an attack response, but as bats approached, they used additional sensory cues in a sequential manner to update their information about prey size and palatability. While both palatable and poisonous small anurans were readily captured, large poisonous toads were approached but not contacted suggesting the use of echolocation for assessment of prey size at close range. Once prey was captured, bats used chemical cues to make final, post-capture decisions about whether to consume the prey. Bats dropped small, poisonous toads as well as palatable frogs coated in toad toxins either immediately or shortly after capture. Our study suggests that echolocation and chemical cues obtained at close range supplement information obtained from acoustic cues at long range. Updating information about prey quality minimizes the occurrence of costly errors and may be advantageous in tracking temporal and spatial fluctuations of prey and exploiting novel food sources. These findings emphasize the sequential, complex nature of prey assessment that may allow exploratory and flexible hunting behaviors.

  9. To breed or not to breed: past reproductive status and environmental cues drive current breeding decisions in a long-lived amphibian.

    Science.gov (United States)

    Cayuela, Hugo; Besnard, Aurélien; Bonnaire, Eric; Perret, Haize; Rivoalen, Justine; Miaud, Claude; Joly, Pierre

    2014-09-01

    Iteroparity is an adaptive response to uncertainty in reproductive success. However, spreading reproductive success over multiple reproduction events during a lifetime is constrained by adult mortality and the stochasticity associated with interactions between external factors and physiological states. The acquisition of information about environmental conditions during the growth of progeny and sufficient resources during the non-reproductive period are key factors for breeding success. Consequently, we hypothesized that long-lived animals may skip a breeding opportunity when information about unfavourable environmental conditions is available. In addition, nutritional constraints could prevent an animal from replenishing its reserves sufficiently to invest in the current breeding period. We investigated these questions using capture-recapture data from a 5-year study on a large population of yellow-bellied toads in a forest in north-eastern France. We took advantage of various advances in multi-state capture-recapture models (e.g. unobservable states and mixture models) to test our hypotheses. Our results show that the combined effects of rainfall deficit and the breeding/non-breeding state of individuals during the past breeding season affect breeding probability during the following breeding opportunity. We also found that females breed less frequently than males, suggesting that the overall energy cost of reproduction differs between genders. Finally, the results indicate that toad survival appears to be negatively influenced by rainfall deficits. We discuss the yellow-bellied toad's reproductive behaviour in term of bet-hedging strategy and life history trait evolution. PMID:24996543

  10. Antiproliferative activity of Rhinella marina and Rhaebo guttatus venom extracts from Southern Amazon.

    Science.gov (United States)

    Ferreira, Paulo Michel Pinheiro; Lima, Daisy Jereissati Barbosa; Debiasi, Bryan Wender; Soares, Bruno Marques; Machado, Kátia da Conceição; Noronha, Janaina da Costa; Rodrigues, Domingos de Jesus; Sinhorin, Adilson Paulo; Pessoa, Cláudia; Vieira, Gerardo Magela

    2013-09-01

    The venom of amphibians is a fascinating source of active substances. In view of their medical importance and aiming to explore the amazing Brazilian biodiversity, we conducted bioprospecting of antiproliferative activity in extracts of Rhinella marina and Rhaebo guttatus toads occurring in the Southern Amazon of Mato Grosso, Brazil. LC-MS and HPLC analysis of the venom extracts of R. marina revealed four bufadienolides (telocinobufagin, marinobufagin, bufalin and resibufogenin. R. guttatus venom extracts contained only marinobufagin. First, R. marina and R. guttatus venom extracts were evaluated for cytotoxicity against tumor cell lines by the MTT assay. All extracts revealed cytotoxicity, where R. marina extracts were comparable to doxorubicin (IC?? values ranging from 0.01 to 0.23 ?g/mL). Only extracts of R. guttatus toad venom caused membrane disruption of human erythrocytes. The extracts were investigated for selective activity by determining their effect on stimulated human peripheral blood mononuclear cells (PBMC) with the Alamar Blue™ assay. The extracts were up to 80-fold more selective against leukemia cells when compared to dividing leukocytes. Aiming to confirm these antiproliferative effects, BrdU incorporation into DNA was measured in HL-60 treated cells with R. marina venom extracts. These extracts decreased BrdU incorporation at both concentrations tested. In summary, nine extracts of R. marina and R. guttatus venom showed pronounced lethal and discriminating effects on tumor lines, especially those from R. marina, highlighting toad parotoid gland secretions as a promising source for novel lead anticancer chemicals. PMID:23796725

  11. Four new species of Oswaldocruzia (Nematoda: Trichostrongylina, Molineoidea Parasitizing amphibians and lizards from Ecuador

    Directory of Open Access Journals (Sweden)

    Badreddine Ben Slimane

    1996-06-01

    Full Text Available Description of four new species of Oswaldocruzia parasitizing Iguanidae and Leptodactylidae from Ecuador, demonstrate that they are morphologically close to each other. Like most of the other neotropical and holarctic Oswaldocruzia , they are characterized by spicules with three main branches: blade, shoe and fork; the division of the fork within the distal third of the spicule length appears to be characteristic of the neotropical species. - Oswaldocruzia bainae n. sp. parasitizing Anolis chrysolepis and Anolis fuscoauratus possesses a synlophe visible only on transversal sections of the body. It is composed of rounded and not pointed ridges. - Oswaldocruzia tcheprakovae n. sp. parasitizing Eleutherodactylus altamazonicus is closely related to O. bainae , but the synlophe is present only in the anterior and posterior extremities of the body. - Oswaldocruzia cassonei n. sp. parasitizing Eleutherodactylus lanthanites is closely related to O. taranchoni, Ben Slimane and Durette-Desset, 1995, a parasite of Bufo marinus from Brazil. It is differentiated by the synlophe and the measurements. - Oswaldocruzia petterae n. sp. parasitizing Leptodactylus pentadactylus is closely related to O. chambrieri, Ben Slimane and Durette-Desset, 1993, parasitizing Bufo and Eleutherodactylus in the same region. It is differentiated since, for an equivalent length of the body, the ridges are almost two times fewer and the spicules smaller.

  12. Four new species of Oswaldocruzia (Nematoda: Trichostrongylina, Molineoidea) Parasitizing amphibians and lizards from Ecuador

    Scientific Electronic Library Online (English)

    Badreddine, Ben Slimane; Marie-Claude, Durette-Desset.

    1996-06-01

    Full Text Available Description of four new species of Oswaldocruzia parasitizing Iguanidae and Leptodactylidae from Ecuador, demonstrate that they are morphologically close to each other. Like most of the other neotropical and holarctic Oswaldocruzia , they are characterized by spicules with three main branches: blade [...] , shoe and fork; the division of the fork within the distal third of the spicule length appears to be characteristic of the neotropical species. - Oswaldocruzia bainae n. sp. parasitizing Anolis chrysolepis and Anolis fuscoauratus possesses a synlophe visible only on transversal sections of the body. It is composed of rounded and not pointed ridges. - Oswaldocruzia tcheprakovae n. sp. parasitizing Eleutherodactylus altamazonicus is closely related to O. bainae , but the synlophe is present only in the anterior and posterior extremities of the body. - Oswaldocruzia cassonei n. sp. parasitizing Eleutherodactylus lanthanites is closely related to O. taranchoni, Ben Slimane and Durette-Desset, 1995, a parasite of Bufo marinus from Brazil. It is differentiated by the synlophe and the measurements. - Oswaldocruzia petterae n. sp. parasitizing Leptodactylus pentadactylus is closely related to O. chambrieri, Ben Slimane and Durette-Desset, 1993, parasitizing Bufo and Eleutherodactylus in the same region. It is differentiated since, for an equivalent length of the body, the ridges are almost two times fewer and the spicules smaller.

  13. Aprendizaje instrumental en anfibios

    Directory of Open Access Journals (Sweden)

    Rub\\u00E9n N. Muzio

    1999-01-01

    Full Text Available Este trabajo presenta una revisión de los estudios realizados acerca de los mecanismos de aprendizaje en anfibios. Se conoce muy poco acerca de los procesos de aprendizaje en anfibios, y aún menos respecto de las relaciones cerebro-aprendizaje. Recientemente hemos comenzado el estudio sistemático del aprendizaje instrumental en el sapo Bufo arenarum dentro de un marco comparativo. Se observaron diversos fenómenos de aprendizaje comunes a una amplia variedad de vertebrados, tales como la adquisición bajo condiciones de entrenamiento masivo y espaciado, la extinción, la recuperación espontánea, el efecto subsiguiente al refuerzo, y el efecto en al adquisición de la magnitud del reforzamiento. Además, comenzamos el análisis de los efectos sobre el aprendizaje de las lesiones del pallium medial (estructura postulada como homóloga al hipocampo de los mamíferos. La lesión del paIlium medial no tuvo efectos sobre el desempeño ni sobre la tasa de captación de agua durante la adquisición. Pero retardó significativamente la extinción de la respuesta instrumental en un corredor recto. Estos datos sugieren que el palli um medial de los sapos juega un papel en la inhibición de respuestas previamente aprendidas. Los resultados de nuestros estudios en el sapo Bufo arenarum aportan datos origi na1es a la limitada información disponible sobre aprendizaje en anfibios.

  14. Caracterización morfológica de larvas de anuros del Noroeste argentino

    Directory of Open Access Journals (Sweden)

    Fabrezi, Marissa

    1997-01-01

    Full Text Available Se analizan caracteres morfológicos en larvas de catorce especies de anuros. Las especies analizadas son Bufo arenarum, B. paracnemis, Leptodadylus chaquensis, L. latinasus, Odontophrynus americanus, O. lavillai, Phrynohyas venulosa, Phyllomedusa sauvagii, Physalaemus biligonigerus, P. cuqui, Pleurodema borellii, P. tucumana, Scinax fuscovaria y S. nasica. Estas especies se desarrollan en charcas temporarias del Noroeste de Argentina. Se caracterizan las larvas de cada especie por el análisis de la morfología externa e interna, caracteres de la cavidad oral, condrocráneo y arcos viscerales. Algunos de estos aspectos morfológicos se discuten con las hipótesis propuestas acerca de larvas generalizadas. We have analyzed morphological characters in tadpoles of fourteen anuran species. The species considered are Bufo arenaum, B. paracnemis, Leptodactylus chaquensis, L. latinasus, Odontopbynus americanus, O.lavillai, Phrynohyas venulosa, Phyllomedusa sauvagii, Physalaemus biligonigerus, P. cuqui, Pleurodema borellii, P. tucumana, Scinax fuscovaria and S. nasica. They develop in similar temporary ponds of Northwestern of Argentina. We characterized the larvae of each species by the analyses on external morphology, internal oral features, chondrocranium and visceral archs. Some of these morphological aspects have been discussed with proposal hypotheses about generalized tadpoles.

  15. Diet of the colubrid snake, Thamnodynastes strigatus (Günther, 1858) from Paraná State, Brazil, with field notes on anuran predation / Dieta da Serpente Colubridae, Thammodynastesstrigatus (Günther, 1858), no Estado do Paraná, Brasil, com notas de predação sobre anuros na natureza

    Scientific Electronic Library Online (English)

    P. S., BERNARDE; J. C., MOURA-LEITE; R. A., MACHADO; M. N. C., KOKOBUM.

    2000-11-01

    Full Text Available São apresentados dados da dieta de Thamnodynastes strigatus (Serpentes: Colubridae), a partir da dissecção de 44 espécimes. No tubo digestivo dos exemplares examinados foram encontrados anfíbios anuros (71,4% da amostra), roedores (14,3%), peixes (10,7%) e lagartos (3,6%). A maioria das espécies de [...] anuros (Bufo sp., Leptodactylus sp., Physalaemus cuvieri e Scinax fuscovarius) encontradas no exame de conteúdo estomacal de T. strigatus, utiliza o solo ou o nível d'água como sítio de vocalização. Também são apresentados dados sobre a observação de eventos de predação na natureza. Abstract in english Dissection of 44 specimens of the colubrid snake Thamnodynastes strigatus (Serpentes: Colubridae) provided data on food habits. Prey items include frogs (71.4% of the sample), rodents (14.3%), fishes (10.7%), and lizards (3.6%). The most of the anuran species recorded (Bufo sp., Leptodactylus sp., P [...] hysalaemus cuvieri and Scinax fuscovarius) are ground dwellers or call at the water level. Field observations provided information on the feeding behavior.

  16. Notes on distribution and current status of herpetofauna in the northern area of Bra?ov County (Romania

    Directory of Open Access Journals (Sweden)

    Tibor SOS

    2007-07-01

    Full Text Available In the northern area of Bra?ov County, the herpetofauna appears to be characteristic for a hilly and low-mountain zone and includes the following species: Salamandra salamandra, Triturus cristatus, Lissotriton vulgaris, Bombina variegata, Pelobates fuscus, Bufo bufo, Pseudepidalea viridis, Hyla arborea, Pelophylax ridibundus, Pelophylax kl. esculentus, Rana dalmatina, Rana temporaria, Rana arvalis, Emys orbicularis, Lacerta agilis, Lacerta viridis, Podarcis muralis, Anguis fragilis colchicus, Coronella austriaca and Natrix natrix. The presence of other three species (Zootoca vivipara, Zamenis longissimus and Vipera berus in this area is also listed in the scientific literature. The status of amphibians and reptiles in the vicinity of human localities is vulnerable and uncertain, being threatened by intensive agricultural and mining activity, overgrazing, deforestation, waste deposition and aggressive human behavior. The further existence of several small populations of R. arvalis, P. muralis and L. viridis is unstable. Undisturbed habitats still exist near the Olt River and in central part of the Northern Per?ani Mountains. The next steps concerning active protection of herpetofauna would be delimitation and protection of habitats, excavation of new breeding sites for amphibian populations and starting herpetological education in this area.

  17. Bufalin inhibits migration and invasion in human hepatocellular carcinoma SK-Hep1 cells through the inhibitions of NF-kB and matrix metalloproteinase-2/-9-signaling pathways.

    Science.gov (United States)

    Chen, Ya-Yin; Lu, Hsu-Feng; Hsu, Shu-Chun; Kuo, Chao-Lin; Chang, Shu-Jen; Lin, Jen-Jyh; Wu, Ping-Ping; Liu, Jia-You; Lee, Ching-Hsiao; Chung, Jing-Gung; Chang, Jin-Biou

    2015-01-01

    Metastasis plays an important role in mortality of cancer patients. Migration and invasion are the major characteristics of tumor metastasis. The induction of matrix metalloproteinases (MMPs) such as MMP-2 and -9 are particularly important for the invasiveness of various cancer cells. Bufalin, a class of toxic steroids, was purified from the skin glands of Bufo gargarizans or Bufo melanostictus; it is known to inhibit proliferation of human cancer cells. In this study, we investigated the antiinvasive mechanisms of bufalin in the human hepatocellular cancer cell line SK-Hep1. Bufalin significantly reduced serum-induced cell invasion and migration. Furthermore, bufalin markedly inhibited MMP-2 and -9 activity, mRNA expression and protein levels in SK-Hep1 cells. Bufalin attenuated phosphoinisitide-3-kinase (PI3K) and phosphorylation of AKT which was associated with reduced levels of nuclear factor kappa B (NF-?B). Bufalin also suppressed protein levels of FAK and Rho A, VEGF, MEKK3, MKK7, and uPA and it diminished NF-?B translocation. Based on these observations, we propose that bufalin is acts as an antiinvasive agent by inhibiting MMP-2 and -9 and involving PI3K/AKT and NF-?B pathways. Bufalin is a potential therapeutic agent that may have efficacy in preventing the invasion and metastasis of malignant liver tumors. PMID:23949904

  18. Effects of Roads on Amphibian Populations : PhD Thesis

    DEFF Research Database (Denmark)

    Hels, T.

    1999-01-01

    Lucky me to have had the chance of enjoying the barely audible sound of calling spadefoot toads on warm spring nights! Right at the breakthrough of spring they arrive at the breeding ponds, by the time when the air becomes heavy with the promising fragrances of spring and early summer. Lucky me to have experienced the wonders of early summer sunrises in the field - and the joy of thawing out frozen fingers after hours of field work around freezing point. Amphibian populations are declining. This worrying fact is what has initiated this work. Some fifty years ago, the life history of frogs and toads was common knowledge to everybody due to personal experience: amphibians were abundant. Noisy and innumerable in spring when reproducing, silent and even more abundant in late summer with both adults and metamorphs leaving the breeding ponds. Today, experiencing frogs and toads is an event, something to talk about. Fortunately, amphibians are still numerous in certain places and hopefully, we will get to a point when we know enough about the declines and their backgrounds to bring the decline to an end. It is my hope that results of this work will add a piece to the puzzle. This work is the result of my three year PhD study at the National Environmental Research Institute, Kalø, and University of Copenhagen. Funded by NERI, the Danish Research Academy, and the Danish Road Directorate, it has dealt mainly with the effects of traffic and roads on amphibian populations. The Spadefoot toad as described above has been studied most intensively, but the work has included common and crested newt, common toad, common frog and moor frog as well. The work has resulted in three manuscripts which form the main part of the thesis: I Quantification of demographic parameters in a Danish metapopulation of Spadefoot toads (Pelobates fuscus Laur.) II The effect of road kills on amphibian populations III Simulating viability of a Spadefoot toad (P. fuscus) metapopulation in a landscape fragmented by a road The manuscripts are preceded bya synopsis which sums up the work and puts it into a broader perspective. In the synopsis, I describe and briefly review the paradigms behind the work, I review and discuss my most important findings, and finally, I point at gaps in our present knowledge: further work that has to be done to improve our understanding of ecological patterns and processes within this field. Although this thesis is basically one woman's work, several people have improved it substantially by making the work more interesting, more appealing, more correct - and not to forget, more fun. I thank my advisors Aksel Bo Madsen and Gösta Nachman for all kinds of valuable advice along the way. Thank you Helle Clausen, Bente Hansen, Tine Hansen, Klaus Nordvig, Sune Thomsen, and Mikkel Ørsberg for skilled field work, and Jesper Bruun-Schmidt, Thøger Dige, and Susanne Nielsen for allowing me to use data from your masters' theses. Thanks are also due to my Swedish colleagues and friends, especially Per Edenhamn, Johan Elmberg, Andreas Seiler, and Per Sjögren-Gulve, for sharing your knowledge and enthusiasm for science with me. Constructive ideas, different approaches, and elaborate discussions are crucial parts of any scientific process: I thank Lenore Fahrig for dedicated and original teaching and discussions during the PhD-course in Landscape Ecology and Wildlife Management at Grimsö, Sweden, December 1995 and Peter Kareiva for new ideas during my stay in your lab in Seattle, Washington, in the autumn of 1997. I am also grateful to Thomas Bregnballe, Erik Buchwald, and Chris Topping for invaluable discussions and for improving various versions of the manuscripts. Finally, I thank Tove Petersen and Kirsten Zaluski for improving my English, and Bo Bendixen for the front page drawing.

  19. Mapping anuran habitat suitability to estimate effects of grassland and wetland conservation programs

    Science.gov (United States)

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

    2012-01-01

    The conversion of the Northern Great Plains of North America to a landscape favoring agricultural commodity production has negatively impacted wildlife habitats. To offset impacts, conservation programs have been implemented by the U.S. Department of Agriculture and other agencies to restore grassland and wetland habitat components. To evaluate effects of these efforts on anuran habitats, we used call survey data and environmental data in ecological niche factor analyses implemented through the program Biomapper to quantify habitat suitability for five anuran species within a 196 km2 study area. Our amphibian call surveys identified Northern Leopard Frogs (Lithobates pipiens), Wood Frogs (Lithobates sylvaticus), Boreal Chorus Frogs (Pseudacris maculata), Great Plains Toads (Anaxyrus cognatus), and Woodhouse’s Toads (Anaxyrus woodhousii) occurring within the study area. Habitat suitability maps developed for each species revealed differing patterns of suitable habitat among species. The most significant findings of our mapping effort were 1) the influence of deep-water overwintering wetlands on suitable habitat for all species encountered except the Boreal Chorus Frog; 2) the lack of overlap between areas of core habitat for both the Northern Leopard Frog and Wood Frog compared to the core habitat for both toad species; and 3) the importance of conservation programs in providing grassland components of Northern Leopard Frog and Wood Frog habitat. The differences in habitats suitable for the five species we studied in the Northern Great Plains, i.e., their ecological niches, highlight the importance of utilizing an ecosystem based approach that considers the varying needs of multiple species in the development of amphibian conservation and management plans.

  20. 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,...

  1. Comparative study of the venoms from three species of bees: effects on heart activity and blood.

    Science.gov (United States)

    Hussein, A A; Nabil, Z I; Zalat, S M; Rakha, M K

    2001-11-01

    Crude venoms from three highly evolved aculeate species: Apis mellifera (highly social bees), Bombus morrisoni (eusocial bees), and Anthophora pauperata (solitary bees), were used for conducting this study to compare the effects of honey bee, bumble bee, and solitary bee venom on toad cardiac muscle activity. In addition, these venoms were tested on rat whole blood in order to determine their ability to induce red blood cell haemolysis. The main toxic effects on isolated toad heart were monitored by ECG after perfusion with different concentrations of each bee venom, and are represented as a decrease in the heart rate (HR) accompanied by an elongation in the P-R interval. A gradual and progressive increase in R-wave amplitude was also noted. Several electrocardiographic changes were noted 5-30 min after envenomation with any of the bee venoms. The mechanism of action of the three bee venoms was determined by direct application of atropine, nicotine, or verapamil to the isolated toad hearts. Comparison of the three venoms revealed that Anthophora pauperata venom is the most effective venom in inducing bradycardia, and it has the strongest negative dromotropic effect. Apis mellifera venom demonstrates the most positive inotropic effect of the three venoms. The effects of bee venom on the blood indices of erythrocyte osmotic fragility (EOF) and plasma albumin levels were studied after incubation of rat blood with each venom. It was noticed that RBCs decreased while Hb content, HCT, MCV, MCH, and MCHC increased, although this change did fluctuate and was not significant. A nonsignificant decrease in EOF was noted after 60 min with any of the venoms used. Incubation of rat whole blood with 1 microg/ml of any of the bee venom solutions revealed a highly significant decrease in plasma albumin levels. It can be concluded that venoms from the three species of bees we tested have negative chronotropic and dromotropic effects on isolated toad heart, with Anthophora pauperata being the most potent. In addition, the venoms have positive inotropic effects withApis mellifera being the most potent. The nonsignificant effects of venom on blood profiles and erythrocyte osmotic fragility, combined with the significant decrease in plasma albumin level suggest a protective effect of plasma albumin against bee venom induced toxicity to erythrocytes. PMID:11695823

  2. Biological effects of high-diluted substances and periodic table of elements

    OpenAIRE

    Cloe Taddei-Ferretti

    2012-01-01

    Background and Aims. There are several experimental evidences for the effects of high-diluted substances (see e.g. C. Taddei-Ferretti, A. Cotugno 1997, on effects of high-diluted drugs on the prevention and control of mice teratogenicity induced by purine derivatives; N.C. Sukul, C. Taddei-Ferretti, S.P. Sinha Babu, A. De, B. Nandi, A. Sukul, R. Dutta-Nag 2000, on high-diluted Nux vomica countering alcohol-induced loss of righting reflex in toads). Also the physical characterization and mecha...

  3. The Otter (Lutra lutra in Central Finland

    Directory of Open Access Journals (Sweden)

    Risto Sulkava

    1994-10-01

    Full Text Available The otter population on the upper tributaries of the Kokemäenjoki-river system was carefully surveyed by snow-tracking in 1985 - 1993. The otter population in the study area increased in the last eight years. All otters appear to be born in summer. The otters travel in their large home range all year round. Traffic (cars, fish traps and fish hatcheries caused the most of otter deaths. The diet is 60% small fish, with frogs and toads being seasonally important.

  4. New species of Parapharyngodon (Nematoda: Pharyngodonidae) in Rhinella marina (Anura: Bufonidae) from Grenada, West Indies

    Science.gov (United States)

    Bursey, Charles; Drake, Michael; Cole, Rebecca; Sterner, Mauritz, III; Pinckney, Rhonda; Zieger, Ulrike

    2013-01-01

    Parapharyngodon grenadaensis n. sp. (Nematoda: Pharyngodonidae) from the large intestine of the cane toad, Rhinella marina, is described and illustrated. Parapharyngodon grenadaensis n. sp. is the 48th species assigned to the genus and the 16th species from the Neotropical region. It differs from other species in the genus by possessing 4 pairs of caudal papillae, an echinate anterior cloacal lip, and a blunt spicule of 67–104 ?m. This is only the second report of R. marina harboring a species of Parapharyngodon.

  5. Radioligand assays for insulin-like growth factor II

    International Nuclear Information System (INIS)

    The work of Rinderknecht and Humbel established that there are two principal somatomedins in human serum which they named insulin-like growth factors I and II (IGF-I and IGF-II). Two structurally similar IGFs have been isolated from rat serum. There is assay evidence that chicken serum and turtle serum also contain these two IGFs but toad and trout serum only seem to contain an IGF-I-like peptide. Because of the presence of these two IGFs, efforts have been made in several laboratories to develop methods which specifically measure these peptides. This chapter focuses on methods on measurement of IGF-II

  6. Life in a Nutshell

    Science.gov (United States)

    University of Nebraska State Museum

    2001-01-01

    In this multi-faceted game (on pages 25-35), learners recreate what happens to creatures in the Brazilian rain forest as they grow from egg to adult—especially those that use fallen, empty Brazil nut pods as a home during some part of their life cycle. These creatures include damsel flies, mosquitoes, toads and poison frogs. The object for players is to make it around the game board, grow faster than the competition, and leave the nutshell nursery before the neighbors eat them. Learners graph the results of all games played. This activity makes a fun connection between life science and math.

  7. Anuran fauna of the Lesotho Highlands in the Khatse Dam catchment area and Jorodane River region

    OpenAIRE

    D.E. van Dijk

    1996-01-01

    Surveys were made of the anuran fauna of the Khatse Dam catchment area in the Lesotho Highlands, and of the region between the Central Mountains and the Thaba Putsoa Range which would be affected by Phase 1B of the Lesotho Highlands Water Scheme, if implemented. The Khatse Dam is at present filling. Seven species of anurans were encountered in the Khatse Dam catchment, and five of them also in the valley to the south-west. Four taxa occur all around central Lesotho, but one, the Gariep toad, ...

  8. Augmentation of nuclear binding capacity for triiodothyronine by aldosterone in tadpole tail

    International Nuclear Information System (INIS)

    Effect of aldosterone on triiodothyrone(T3)-binding to the nuclear fraction of the tail of toad tadpoles was investigated in vitro. T3-binding was increased by adding aldosterone to the incubation medium. Scatchard analysis revealed that aldosterone (3.4 x 10-6M) increased the maximum binding capacity by 40% and that the steroid scarcely affected the value of dissociation constant. Elevation of thyroid hormone sensitivity in the presence of corticoid seems to be closely related to the corticoid-induced increase in nuclear binding capacity for thyroid hormones. (J.P.N.)

  9. Amphibian Bioacoustics

    Science.gov (United States)

    Christensen-Dalsgaard, Jakob

    Anuran amphibians (frogs and toads) of most of the 3,500 species that exist today are highly vocal animals. In most frogs, males will spend considerable energy on calling and incur sizeable predation risks and the females’ detection and localization of the calls of conspecific males is often a prerequisite for successful mating. Therefore, acoustic communication is evidently evolutionarily important in the anurans, and their auditory system is probably shaped by the selective pressures associated with production, detection and localization of the communication calls.

  10. ARMI National Atlas for Amphibian Distributions

    Science.gov (United States)

    This site, from The Amphibian Research and Monitoring Initiative (ARMI), is a compilation of current and historic records of amphibian occurrences. The atlas is organized taxonomically. There are separate sections for frogs and toads, and salamanders and newts. The location of each species is mapped separately. The ARMI Atlas is meant to be an educational tool for people wanting to learn or teach others about amphibians. It can also serve as a reference for habitat managers and researchers, identifying areas where more research is needed, as well as providing information about research that has previously been done.

  11. Complete nucleotide sequence of an endogenous retrovirus from the amphibian, Xenopus laevis

    International Nuclear Information System (INIS)

    We report the first full-length sequence of an endogenous amphibian retrovirus derived from the African clawed toad Xenopus laevis. The virus, termed Xen1, has one of the largest endogenous retroviral genomes described to date of over 10 kb in length and it also has a relatively complex genomic organisation consisting of LTR-orf1, orf2, gag, pol, env-LTR. Orfs 1 and 2 are novel, duplicated genes of unknown function. Phylogenetic analysis indicates that Xen1 is most closely related to the ?-retroviruses WDSV and WEHV types 1 and 2, which are large, complex exogenous retroviruses present within Walleye fish

  12. Synergistic Effects of Copper and Butylic Ester of 2,4-Dichlorophenoxyacetic Acid (Esternon Ultra on Amphibian Embryos

    Directory of Open Access Journals (Sweden)

    Jorge Herkovits

    2006-12-01

    Full Text Available Cu2+ and butylic ester of 2,4-Dichlorophenoxyacetic acid as Esternon Ultra (2,4-D toxicity on Bufo arenarum embryos were evaluated by means of a short-term chronic toxicity test (AMPHITOX. The NOEC values for Cu and 2,4-D were 0.02 mg/L and 2 mg/L respectively. The toxicity profile curves for Cu and 2,4-D were reported. The interactions of the metal and the herbicide were evaluated by combined treatments with different concentrations of Cu and 2,4-D. Although in all cases, a synergistic effect between these chemicals was observed, the combination of concentrations exerting low level effects in isolated treatments resulted in more adverse embryonic survival. Considering that both products are extensively used in agroecosystems, this fact could be of concern for non target species like amphibians.

  13. Distribution of the herpetofauna community associated to four areas with different interference degree in Gorgona Island, Colombian pacific

    International Nuclear Information System (INIS)

    A total of 1840 individuals from 28 species (19 reptiles and 9 amphibians) were found in Gorgona Island, during June and July 2001. Based on 32 transects placed in four areas with different antropic perturbation degree (Prison, palm plantations, secondary forest and primary forest) it was found that the species richness was higher at the secondary forest. The species registered at primary and secondary forest where very similar as well as the species present at the prison and the palm plantations. A Canonical Correspondence Analysis (CCA) showed that Boa constricto1; Basiliscus galeritus. Ameiva bridgesii and Epipedobates boulengeri were found to be associated to open areas and their distribution was hardly affected by the environmental temperature. From the following species associated with forested areas, the canopy cover over the micro habitat influenced the distribution of Eleutherodactylus gularis. Eleutherodactylus achatinus and Bothrops atrox. While the understory cover influenced the distribution of Atelopus elegans. Bufo typhonius. Micrurus mipartitus y Enyalioides heterolepis

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

    Directory of Open Access Journals (Sweden)

    Marchenkovskaya ?. ?.

    2013-04-01

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

  15. Helminths parasites of freshwater fishes from Pirassununga, SP, Brazil

    Directory of Open Access Journals (Sweden)

    A. Kohn

    1985-09-01

    Full Text Available Twelve species of parasitic helminths, seven trematodes, four nematodes and one acanthocephalan are reported from various hosts. Creptotrema lynchi, a parasite from Bufo marinus in Colombia, is described for the first time in fish and from Brazil, parasitizing two different species. A list of the host species, measurements and figures of most parasites are included with particular reference to the tegument of Bellumcorpus major recovered from a new host. The genus Zonocotyloides Padilha, 1978 is considered a synonym of Zonocotyle and the new combination: Zonocotyle haroltravassosi is proposed to the species Zonocotyloides haroltravassosi Padilha, 1978. The nematodes Cucullanus pinnai and Procamallanus (Spirocamallanus inopinatus and the trematode Pararhipidocotyle jeffersoni are reported in new hosts. The description of the acanthocephalan Neoechinorhynchus curemais (new locality record is supplemented. Other parasites recovered include the nematodes Travnema travnema (new locality record, Rondonia rondoni and the digenetic trematodes Cladocystis intestinalis, Pseudosellacotyla lutzi (new locality record, Teratotrema sp. and Zonocotyle bicaecata.No presente trabalho são apresentados sete trematódeos, quatro nematóides e um acantocéfalo parasitas de diferentes espécies de peixes do rio Mogi-Guassu. Creptotrema lynchi, tramatódeo descrito originalmente de anfíblio (Bufo marinus na Colômbia, é referido pela primeira vez em peixes e no Brasil. Bellumcorpus major é assinalado em um novo hospedeiro e são apresentados novos dados morfológicos referentes ao tegumento. O gênero Zonocotyloides Padilha, 1978 é considerado sinônimo de Zonocotyle Travassos, 1948 e é proposta uma nova combinação para a espécieZonocotyloides haroltravassosi Padilha, 1978. Os nematóides Cucullanus pinnai e Procamallanus (Spirocamallanus inopinatus e o trematódeo Pararhipidocotyle jeffersoni são assinalados em novos hospedeiros. O acantocéfalo Neoechinorhynchus curemai é redescrito de nova localidade. São também registrados nematóides Travnema travnema (referido em nova localidade e Rondonia rondoni; e os trematódeos Cladocystis intestinalis, Pseudosellacotyla lutzi (em nova localidade, Teratotrema sp. e Zonocotyle bicaecata.

  16. The annual number of breeding adults and the effective population size of syntopic newts (Triturus cristatus, T. marmoratus).

    Science.gov (United States)

    Jehle, R; Arntzen, J W; Burke, T; Krupa, A P; Hödl, W

    2001-04-01

    Pond-breeding amphibians are deme-structured organisms with a population genetic structure particularly susceptible to demographic threats. We estimated the effective number of breeding adults (Nb) and the effective population size (Ne) of the European urodele amphibians Triturus cristatus (the crested newt) and T. marmoratus (the marbled newt), using temporal shifts in microsatellite allele frequencies. Eight microsatellite loci isolated from a T. cristatus library were used, five of which proved polymorphic in T. marmoratus, albeit with high frequencies of null alleles at two loci. Three ponds in western France were sampled, situated 4-10 kilometers apart and inhabited by both species. Parent-offspring cohort comparisons were used to measure Nb; samples collected at time intervals of nine or 12 years, respectively, were used to measure Ne. The adult population census size (N) was determined by mark-recapture techniques. With one exception, genetic distances (FST) between temporal samples were lower than among populations. Nb ranged between 10.6 and 101.8 individuals, Ne ranged between 9.6 and 13.4 individuals. For the pond where both parameters were available, Nb/N (overall range: 0.10-0.19) was marginally larger than Ne/N (overall range: 0.09-0.16), which is reflected in the temporal stability of N. In line with the observed differences in reproductive life-histories between the species, Nb/N ratios for newts were about one order of magnitude higher than for the anuran amphibian Bufo bufo. Despite of the colonization of the study area by T. cristatus only some decades ago, no significant genetic bottleneck could be detected. Our findings give rise to concerns about the long-term demographic viability of amphibian populations in situations typical for European landscapes. PMID:11348493

  17. Macroinvertebrates as tadpole food: importance and body size relationships Macroinvertebrados como alimento de girinos: importância e relações com tamanho de corpo

    Directory of Open Access Journals (Sweden)

    Silvia L. Dutra

    2005-12-01

    Full Text Available Macroinvertebrates as food were recorded for three anurans tadpoles: Hyla saxicola (Bokermann, 1964 (Hylidae, Scinax machadoi (Bokermann & Sazima, 1973 (Hylidae, and Bufo rubescens (Lutz, 1925 (Bufonidae. These species are commonly found in the mountain streams at Serra do Cipó National Park, Minas Gerais State, Brazil. Tadpoles were collected in pools of second-order reach in Mascates stream and third and fourth order reaches of Indaiá stream from March-October, 2003. Biometrical data were recorded before dissecting each individual and a feeding importance index was estimated. Eight taxa of chironomids and three taxa of mayfly exuviae were found in the guts, but no significantly differences were found between tadpole species (ANOVA, p > 0.05. The results support the drift transport hypothesis that predicts that tadpoles commonly ingest suspended matter in lotic ecosystems, are generalist feeders, and macroinvertebrates are probably incidental ingested.A presença de macroinvertebrados como item na dieta de girinos foi estudada para as espécies Hyla saxicola (Bokermann, 1964 (Hylidae, Scinax machadoi (Bokermann & Sazima, 1973 (Hylidae e Bufo rubescens (Lutz, 1925 (Bufonidae. Estas espécies são comumente encontradas nos córregos de altitude no Parque Nacional da Serra do Cipó, Estado de Minas Gerais, Brasil. Os girinos foram coletados em poções em um trecho de segunda ordem no córrego Mascates, e em trechos de terceira e quarta ordens no córrego Indaiá, entre março e outubro de 2003. Medidas biométricas foram mensuradas antes da dessecação de cada indivíduo e foi estimado um índice de importância de alimentação para os macroinvertebrados encontrados. Oito taxa de Chironomidae e três taxa de exúvias de Ephemeroptera foram encontrados, mas não houve diferenças significativas entre os macroinvertebrados encontrados nas espécies de girinos (ANOVA, p > 0,05. Os resultados obtidos corroboram a hipótese de transporte por deriva que prediz que os girinos comumente ingerem partículas orgânicas em suspensão, são generalistas quanto à sua alimentação e os macroinvertebrados são provavelmente ingeridos acidentalmente.

  18. The nerve protection and in vivo therapeutic effect of Acalypha indica extract in frogs

    Directory of Open Access Journals (Sweden)

    Ernie H. Purwaningsih

    2010-05-01

    Full Text Available Aim To demonstrate nerve protection and/or treatment effect of Acalypha indica Linn. extract on nerve paralysis induced by subcutaneus injection of pancuronium bromide on frog’s back.Methods The study was performed on sixty frogs (Bufo melanostictus Schneider that divided into two groups, i.e. the neuro-protection and neuro-therapy group. Each group was divided further into 6 sub-treatment groups: negative control group treated by water and positive control group treated by piracetam, treatment groups received the extracts 200, 300, 400, 500 mg/kgBW. Pancuronium bromide 0.2% (1 : 20 dilutions were injected subcutaneously as muscle relaxant. The protective effect was studied by giving the extract orally, 1 hour prior to injection; while the therapeutic effect of the extract was studied by 10 minute treatment after injecting pancuronium bromide solution. The parameters measured were the onset and duration of paralysis (in minutes and the recovery time (time needed to recover into normal condition.Results The study showed significantly different protective effect of Acalypha indica Linn. root water extract at 400 and 500 mg/KgBW compared to negative control group and positive control group (piracetam (p < 0.05; while the therapeutic effect was obvious at the dose 200-500 mg/KgBW compared to negative control group (p = 0.000. There was no significant difference compared to positive control group (piracetam, except at 300 mg/KgBW (p = 0.012.Conclusion These results have proven that the water extract of Acalypha indica Linn. root has comparable protective and treatment effect on nerves system, as piracetam, but further studies should be performed to provide more evidences particularly pharmacokinetic and pharmacodynamic studies on two animal models that commonly used. (Med J Indones 2010; 19:96-102Keywords: Acalypha indica Linn, Bufo melanostictus Schneider, nerve-protection

  19. Macroinvertebrates as tadpole food: importance and body size relationships / Macroinvertebrados como alimento de girinos: importância e relações com tamanho de corpo

    Scientific Electronic Library Online (English)

    Silvia L., Dutra; Marcos, Callisto.

    2005-12-01

    Full Text Available A presença de macroinvertebrados como item na dieta de girinos foi estudada para as espécies Hyla saxicola (Bokermann, 1964) (Hylidae), Scinax machadoi (Bokermann & Sazima, 1973) (Hylidae) e Bufo rubescens (Lutz, 1925) (Bufonidae). Estas espécies são comumente encontradas nos córregos de altitude no [...] Parque Nacional da Serra do Cipó, Estado de Minas Gerais, Brasil. Os girinos foram coletados em poções em um trecho de segunda ordem no córrego Mascates, e em trechos de terceira e quarta ordens no córrego Indaiá, entre março e outubro de 2003. Medidas biométricas foram mensuradas antes da dessecação de cada indivíduo e foi estimado um índice de importância de alimentação para os macroinvertebrados encontrados. Oito taxa de Chironomidae e três taxa de exúvias de Ephemeroptera foram encontrados, mas não houve diferenças significativas entre os macroinvertebrados encontrados nas espécies de girinos (ANOVA, p > 0,05). Os resultados obtidos corroboram a hipótese de transporte por deriva que prediz que os girinos comumente ingerem partículas orgânicas em suspensão, são generalistas quanto à sua alimentação e os macroinvertebrados são provavelmente ingeridos acidentalmente. Abstract in english Macroinvertebrates as food were recorded for three anurans tadpoles: Hyla saxicola (Bokermann, 1964) (Hylidae), Scinax machadoi (Bokermann & Sazima, 1973) (Hylidae), and Bufo rubescens (Lutz, 1925) (Bufonidae). These species are commonly found in the mountain streams at Serra do Cipó National Park, [...] Minas Gerais State, Brazil. Tadpoles were collected in pools of second-order reach in Mascates stream and third and fourth order reaches of Indaiá stream from March-October, 2003. Biometrical data were recorded before dissecting each individual and a feeding importance index was estimated. Eight taxa of chironomids and three taxa of mayfly exuviae were found in the guts, but no significantly differences were found between tadpole species (ANOVA, p > 0.05). The results support the drift transport hypothesis that predicts that tadpoles commonly ingest suspended matter in lotic ecosystems, are generalist feeders, and macroinvertebrates are probably incidental ingested.

  20. Mechanism of Action of the Egyptian Garlic "Allium sativum" on Excitable Tissues

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    Aida Ahmed Hussein

    2003-01-01

    Full Text Available Garlic has been used for millennia in the traditional medicine practice of many cultures to treat cardiovascular and others disorders. In this study, mechanism of action of garlic on several excitable membranes have been discussed. three groups of isolated toads hearts were used to investigate the effect as well as the mechanism of garlic solution (4 g ml-1 on the physiological properties of the myocardium through the electrocardiogram (ECG recordings. A significant decrease of the heart rate (negative chronotropism accompanied by significant increase in the conduction time (positive dromotropism were resulted following the garlic application and sustained 20 min. Several cases of heart block were recorded after 10 min from garlic perfusion. Application of atropine didn`t abolish the effect on the myocardium. Moreover, an increase of the ventricular voltage has been noticed after 10 min from the garlic application. The calcium-channel blocker verapamil apparently abolished the positive inotropic effect of the garlic. Smooth-muscle activity was studied before and after garlic application (4 g ml-1. An increase of the spontaneous contraction of rabbit-duodenum was established by garlic solution. Blockade the M3 muscarinic receptors of the smooth muscle by atropine sustained normal contraction. Perfusion of toad gastrocnemius-muscle/sciatic-nerve preparation with (4 g ml-1 garlic solution weakened the mechanical contraction of the muscle without recovery. Pretreatment with the nicotinic receptor antagonist gallamine sustained normal contraction of the skeletal muscle.

  1. A novel signalling pathway originating in mitochondria modulates rat skeletal muscle membrane excitability

    Science.gov (United States)

    Ørtenblad, Niels; Stephenson, D George

    2003-01-01

    Single skeletal muscle fibres from rat and cane toad were mechanically skinned and stimulated either electrically by initiating action potentials in the sealed transverse (t-) tubular system or by ion substitution causing depolarisation of the t-system to pre-determined levels. Depression of mitochondrial ATP-producing function with three diverse mitochondrial function antagonists (azide: 1–10 mm; oligomycin 1 ?g ml?1 and carbonyl cyanide 4-trifluoromethoxyphenylhydrazone (FCCP) 1 ?m), under conditions in which the cytosolic ATP was maintained high and constant, invariably reduced the excitability of rat fibres but had no obvious effect on the excitability of toad fibres, where mitochondria are less abundant and differently located. The reduction in excitability linked to mitochondria in rat fibres appears to be caused by depolarisation of the sealed t-system membrane. These observations suggest that mitochondria can regulate the functional state of mammalian muscle cells and have important implications for understanding how the balance between ATP utilisation and ATP production is regulated at the cellular level in general and in mammalian skeletal muscle fibres in particular. PMID:12611917

  2. Crowd Sourcing for Conservation: Web 2.0 a Powerful Tool for Biologists

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    William E. Boyd

    2012-05-01

    Full Text Available The advent and adoption of Web 2.0 technologies offers a powerful approach to enhancing the capture of information in natural resource ecology, notably community knowledge of species distributions. Such information has previously been collected using, for example, postal surveys; these are typically inefficient, with low response rates, high costs, and requiring respondents to be spatially literate. Here we describe an example, using the Google Maps Application Programming Interface, to discuss the opportunities such tools provide to conservation biology. Toad Tracker was created as a prototype to demonstrate the utility of this technology to document the distribution of an invasive vertebrate pest species, the cane toad, within Australia. While the technological aspects of this tool are satisfactory, manager resistance towards its use raises issues around the public nature of the technology, the collaborative (non-expert role in data collection, and data ownership. We conclude in suggesting that, for such tools to be accepted by non-innovation adopters, work is required on both the technological aspects and, importantly, a cultural change is required to create an environment of acceptance of the shifting relationship between authority, expertise and knowledge.

  3. FREQUENCY DISTRIBUTIONS OF 90SR AND 137CS CONCENTRATIONS IN AN ECOSYSTEM OF THE 'RED FOREST' AREA IN THE CHERNOBYL EXCLUSION ZONE

    Energy Technology Data Exchange (ETDEWEB)

    Farfan, E.; Jannik, T.; Caldwell, E.

    2011-10-01

    In the most highly contaminated region of the Chernobyl Exclusion Zone: the 'Red Forest' site, the accumulation of the major dose-affecting radionuclides ({sup 90}Sr and {sup 137}Cs) within the components of an ecological system encompassing 3,000 m{sup 2} were characterized. The sampled components included soils (top 0-10 cm depth), Molina caerulea (blue moor grass), Camponotus vagus (carpenter ants) and Pelobates fuscus (spade-footed toad). In a comparison among the components of this ecosystem, the {sup 90}Sr and {sup 137}Cs concentrations measured in 40 separate grids exhibited significant differences, while the frequency distribution of the values were close to a logarithmically normal leptokurtic distribution with a significant right-side skew. While it is important to identify localized areas of high contamination or 'hot spots,' including these values in the arithmetic mean may overestimate the exposure risk. In component sample sets that exhibited logarithmically normal distribution, the geometrical mean more accurately characterizes a site. Ideally, risk assessment is most confidently achieved when the arithmetic and geometrical means are most similar, meaning the distribution approaches normal. Through bioaccumulation, the highest concentrations of {sup 90}Sr and {sup 137}Cs were measured in the blue moor grass and spade-footed toad. These components also possessed distribution parameters that shifted toward a normal distribution.

  4. All-optical half-adder/half-subtractor using terahertz optical asymmetric demultiplexer.

    Science.gov (United States)

    Gayen, Dilip Kumar; Chattopadhyay, Tanay; Bhattacharyya, Arunava; Basak, Saikat; Dey, Dipanti

    2014-12-20

    Logic gates are the fundamental building blocks of digital systems. Using these logic gates, one can perform different logic and arithmetic operations. All-optical logic and arithmetic operations are very much expected in high-speed communication systems. In this paper, we present a model to perform addition/subtraction operations on two binary digits based on a terahertz optical asymmetric demultiplexer (TOAD). Using four TOAD-based switches, we have designed a half-adder and half-subtractor circuit. The approach to designing all-optical arithmetic circuits not only enhances the computational speed but is also capable of synthesizing light as inputs to produce the desired outputs. The main advantages of this circuit are that synchronization between inputs is eliminated and simultaneous addition and subtraction operations are realized at the outputs. This circuit is designed theoretically and verified through numerical simulations. The impact of the control pulse energy, gain recovery time, and the input data pulse width on the extinction ratio, contrast ratio, amplitude modulation, Q-factor, and relative opening of the pseudo-eye diagram of the switching outcome is explored and assessed by means of numerical simulations. PMID:25608188

  5. [Selecting solvent and solubilizer for puerarin nasal drops by solubility and irritation].

    Science.gov (United States)

    Cheng, Yan-ke; Guo, Yi-wang; Shang, Ke-xin; Guo, Qing-li; Du, Shou-ying; Lu, Yang

    2014-11-01

    In order to test the equilibrium solubility of puerarin in different solvents and solubilizer,cilia toxicity and irritation of these excipient, the balance method, toad in the ciliary body toxicity and rat nasal mucosa irritation were used respectively. Results showed that puerarin solubility was 56.44 g x L(-1) in combined solvent of 30% PEG200 and 10% Kolliphor HS 15. With normal saline solution as negative control and sodium deoxycholate as positive control, the effects of 30% PEG200, 30% PEG 400, 10% Kolliphor HS 15 and combination of 30% of PEG200 and 10% Kolliphor HS 15 on toad palate cilium were observed and cilia movement duration was recorded. The results indicated that there was no significant difference in cilia movement duration among 30% PEG200, 10% Kolliphor HS 15 and normal saline group. The rats long-term nasal mucous membrane irritation of 30% PEG 400, 10% Kolliphor HS 15, which had no cilia toxicity, was studied, with normal saline solution as negative control. There were no significant difference revealed on rat nasal mucosa epithelial thickness among 30% PEG 400, 10% Kolliphor HS 15 and normal saline. Above researches showed 30% PEG 400, 10% Kolliphor HS 15 was ideal for solubility of puerarin nasal drops and showed a lower cilia toxicity and irritation, and can be used as the solvent and solubilizer of puerarin nasal drops. PMID:25850262

  6. Elevated Corticosterone Levels and Changes in Amphibian Behavior Are Associated with Batrachochytrium dendrobatidis (Bd) Infection and Bd Lineage

    Science.gov (United States)

    2015-01-01

    Few studies have examined the role hormones play in mediating clinical changes associated with infection by the parasite Batrachochytrium dendrobatidis (Bd). Glucocorticoid (GC) hormones such as corticosteroids (CORT) regulate homeostasis and likely play a key role in response to infection in amphibians. We explore the relationship between CORT release rates and Bd infection in tadpoles of the common midwife toad, Alytes obstetricians, using a non-invasive water-borne hormone collection method across seven populations. We further examined whether tadpoles of A. muletensis infected with a hypervirulent lineage of Bd, BdGPL, had greater CORT release rates than those infected with a hypovirulent lineage, BdCAPE. Finally, we examined the relationship between righting reflex and CORT release rates in infected metamorphic toads of A. obstetricans. We found an interaction between elevation and Bd infection status confirming that altitude is associated with the overall severity of infection. In tandem, increasing elevation was associated with increasing CORT release rates. Tadpoles infected with the hypervirulent BdGPL had significantly higher CORT release rates than tadpoles infected with BdCAPE showing that more aggressive infections lead to increased CORT release rates. Infected metamorphs with higher CORT levels had an impaired righting reflex, our defined experimental endpoint. These results provide evidence that CORT is associated with an amphibian’s vulnerability to Bd infection, and that CORT is also affected by the aggressiveness of infection by Bd. Together these results indicate that CORT is a viable biomarker of amphibian stress. PMID:25893675

  7. Population differentiation of temperate amphibians in unpredictable environments.

    Science.gov (United States)

    Chan, Lauren M; Zamudio, Kelly R

    2009-08-01

    Amphibians are a globally distributed and diverse lineage, but much of our current understanding of their population genetic structure comes from studies in mesic temperate habitats. We characterize the population genetic structure of two sympatric explosive breeding amphibians in the southwestern deserts of the United States: the Great Plains toad (Anaxyrus cognatus) and Couch's spadefoot toad (Scaphiopus couchii). For both species, we find limited genetic differentiation even between populations in adjacent valleys separated by dispersal barriers such as mountainous habitats. To understand how population genetic patterns in these two arid-adapted species compare to taxa in more mesic environments, we computed a standardized measure of population differentiation for A. cognatus, S. couchii, and for pond-breeding amphibians that inhabit mesic temperate environments. Our results indicate that the arid-adapted species have lower population genetic structure at fine and moderate scales than most other amphibian species we surveyed. We hypothesize that stochasticity in the availability of appropriate breeding sites as well as landscape homogeneity may result in increased population connectivity in desert-adapted frogs. Future work examining fine-scale population structure in amphibians from a diversity of habitats will test the generality of our findings. Intraspecific comparisons among localities with varied seasonality and habitats will be particularly useful for investigating the interaction between species-typical population dynamics and environmental characteristics as determinants of population connectivity in pond-breeding amphibians. PMID:19573030

  8. Dosagem de marcadores cardíacos CK-MB e TnIc e eletrólitos no envenenamento experimental por veneno de sapo em cães

    Directory of Open Access Journals (Sweden)

    Annelise C. Camplesi

    2009-08-01

    Full Text Available Dentre os sinais sistêmicos causados pelo envenenamento por veneno de sapo (bufotoxina em cães, os efeitos cardiotóxicos são um dos mais importantes. O objetivo deste estudo foi avaliar as potenciais alterações no músculo cardíaco de cães envenenados experimentalmente por veneno de sapo e observar as alterações eletrolíticas que podem ocorrer nesse tipo de envenenamento. Utilizaram-se 20 cães divididos em grupo controle (n=5 e grupo envenenado (n=15. O veneno de sapo foi extraído por meio de compressão manual das glândulas paratóides. Após anestesia geral, os cães do grupo controle receberam placebo (solução fisiológica e os do grupo envenenado uma alíquota do veneno por sonda orogástrica. As colheitas de sangue para dosagem dos marcadores cardíacos foram realizadas seis e 24 horas após o envenenamento. As colheitas de sangue para dosagem dos eletrólitos foram realizadas antes e duas, quatro, seis e 12 horas após o envenenamento. A análise estatística empregada foi o teste não-paramétrico de Mann-Withney (PAmong the systemic signs of toad venom (bufotoxin poisoning in dogs, the cardiotoxic effects are one of the most important. Thus, the objective of this experiment was to evaluate potential changes in the cardiac muscle in dogs poisoned experimentally by toad venom and to observe the eletrolyte alterations which may occur in this condition. Twenty dogs divided into control group (n=5 and poisoned group (n=15 were utilized. The toad venom was extracted by manual compression of the paratoidic glands. After general anesthesia, dogs in the control group received placebo and dogs in the poisoned group received the venom by orogastric catheter. Samples for dosage were collected 6 hours and 24 hours after poisoning and 0, 2, 4, 6 and 12 hours after poisoning for electrolytes dosage. The Man-Withney test was used for statistical analysis (P<0.05. The poisoned dogs showed (saline elevated levels of cardiac markers CK-MB and TnIc, confirming the cardiotoxic effect of the bufotoxin. Hypokalemia and hypocalcemia were also observed.

  9. Climate and environment of the earliest West European hominins inferred from amphibian and squamate reptile assemblages: Sima del Elefante Lower Red Unit, Atapuerca, Spain

    Science.gov (United States)

    Blain, Hugues-Alexandre; Bailon, Salvador; Cuenca-Bescós, Gloria; Bennàsar, Maria; Rofes, Juan; López-García, Juan Manuel; Huguet, Rosa; Arsuaga, Juan Luis; Bermúdez de Castro, José Maria; Carbonell, Eudald

    2010-11-01

    The Sima del Elefante cave, in the Sierra de Atapuerca (Burgos, Spain), is famous for the fact that level TE9 of its Lower Red Unit recently delivered the oldest hominin remains of Western Europe, identified as Homo antecessor and dated by biostratigraphy and radiometric methods to ca 1.2 Ma. Given the importance of this discovery, every effort is being made to reconstruct the landscapes where these hominins once thrived. The amphibian and squamate reptile assemblage of the Sima del Elefante Lower Red Unit is here studied for the first time. The faunal list comprises at least 17 species (roughly 12,000 bone fossil remains): Salamandra salamandra, Triturus cf. marmoratus, Alytes obstetricans, Pelobates cultripes, Pelodytes punctatus, Bufo bufo, Bufo calamita, Hyla arborea, Rana sp., cf. Pelophylax sp., Lacerta s.l., small-sized indeterminate lacertids, Anguis fragilis, Natrix cf. natrix, Natrix cf. maura, Coronella cf. girondica and Vipera sp. As the amphibians and squamate reptiles do not differ at species level from the extant herpetofauna of the Iberian Peninsula, they can contribute to the reconstruction of the landscape and climate. In this paper, the mutual climatic range and habitat weighting methods are applied to the amphibian and squamate reptile assemblages in order to estimate quantitative data. The results from the squamate and amphibian study indicate that during the hominin presence the mean annual temperature (MAT = 10-13 °C) was always slightly warmer than at present and the mean annual precipitation (MAP = 800-1000 mm) was greater than today in the Burgos area. The landscape had open habitats in the vicinity of the Atapuerca caves throughout the sequence, with wet points in the surrounding area, and a predominance of humid meadows and open woodlands. These results mainly agree with those for large mammals, small mammals and the pollen analysis. The climate and landscape of TE-LRU are very similar to those reconstructed for the TD6 "Aurora Stratum" level of the Gran Dolina cave (Atapuerca) that has yielded H. antecessor remains at ca 960 ky. When compared with Orce localities of similar age (i.e. Barranco León D and Fuente Nueva 3) that have yielded strong evidence of hominin presence (mainly lithic industries), it appears that they have a fairly similar environmental pattern, having in common a good representation of woodland and water-edge areas, even though dry environments are more developed in Barranco León D and Fuente Nueva 3 than in Sima del Elefante and Gran Dolina. H. antecessor may have thus lived under a warm-humid climate in a patchy landscape mainly composed of humid meadows and riparian woodlands. Such a landscape may have provided favourable conditions for a high diversity of large mammals, as well as for hiding and escaping from large carnivores.

  10. Light and scanning electron microscopical examination of the third stage larva of Physocephalus dromedarii (Nematoda: Spirocercidae)-an abomasal nematode of the one humped camel (Camelus dromedarius).

    Science.gov (United States)

    Schuster, Rolf K; Wibbelt, Gudrun; Sivakumar, Saritha; Reiczigel, J

    2015-05-01

    The life cycle of Physocephalus dromedarii was studied under experimental conditions. Larvae obtained from naturally infected Scarabaeus cristatus and Aphodius sp. (Coleoptera: Scarabaeidae) were measured and examined in light and scanning electron microscopy and used to infect a dromedary as final host as well as chicken, mice and a toad as possible paratenic hosts. Larvae with the same morphology and similar measurements were found in naturally infected reptiles (Trapelus flavimaculatus, Eryx jayakari, Cerastes gasperettii). Body length of examined larvae varied between 1450 and 1700 ?m. Dorsal, ventral and lateral lips, peg-like papillae and amphideal pits are located on the cephalic cone. There are two asymmetrical cervical deirids, long simple lateral wings and a knob-like posterior end covered with minute spines. In the camel, patency is reached within 12 weeks after infection while larvae in paratenic hosts migrate into the wall of the alimentary tract and become dormant. PMID:25687524

  11. A new species of Melanophryniscus (Anura, Bufonidae from Uruguay Una nueva especie de Melanophryniscus (Anura, Bufonidae del Uruguay

    Directory of Open Access Journals (Sweden)

    Raúl Maneyro

    2008-06-01

    Full Text Available A new species of bufonid toad of the genus Melanophryniscus from northern Uruguay is described. It is included in the M. moreirae group and its external morphology is similar to Melanophryniscus sanmartini. Melanophryniscus sp. nov. is distinguished by having a light brown dorsal coloration with six darker longitudinal glandular ridges on the dorsal surface of the body and the gular region uniformly black.Se describe una nueva especie de anuro bufónido del género Melanophryniscus, procedente del norte de Uruguay. La nueva especie se incluye en el grupo M. moreirae y es similar, en cuanto a su morfología externa, con Melanophryniscus sanmartini. Melanophryniscus sp. nov. se distingue por presentar una coloración dorsal castaño clara con seis cordones glandulares longitudinales más oscuros en la superficie dorsal del cuerpo y la región gular de color negro uniforme.

  12. A new species of Melanophryniscus (Anura, Bufonidae) from Uruguay / Una nueva especie de Melanophryniscus (Anura, Bufonidae) del Uruguay

    Scientific Electronic Library Online (English)

    Raúl, Maneyro; Daniel E., Naya; Diego, Baldo.

    2008-06-01

    Full Text Available Se describe una nueva especie de anuro bufónido del género Melanophryniscus, procedente del norte de Uruguay. La nueva especie se incluye en el grupo M. moreirae y es similar, en cuanto a su morfología externa, con Melanophryniscus sanmartini. Melanophryniscus sp. nov. se distingue por presentar una [...] coloración dorsal castaño clara con seis cordones glandulares longitudinales más oscuros en la superficie dorsal del cuerpo y la región gular de color negro uniforme. Abstract in english A new species of bufonid toad of the genus Melanophryniscus from northern Uruguay is described. It is included in the M. moreirae group and its external morphology is similar to Melanophryniscus sanmartini. Melanophryniscus sp. nov. is distinguished by having a light brown dorsal coloration with six [...] darker longitudinal glandular ridges on the dorsal surface of the body and the gular region uniformly black.

  13. No detection of chytrid in first systematic screening of Bombina variegata pachypus (Anura: Bombinatoridae in Liguria, northern Italy

    Directory of Open Access Journals (Sweden)

    Stefano Canessa

    2013-07-01

    Full Text Available The Apennine Yellow-bellied toad Bombina variegata pachypus, a small anuran endemic to peninsular Italy, has been declining throughout its range over the last 30 years. Although mortality by chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis, was first reported for the species in 2004, its role in the decline has not yet been assessed. Between 2011 and 2012 we sampled eight populations of B. v. pachypus in Liguria, northern Italy, swabbing 86 and 143 individuals respectively, corresponding to between 24 and 80% of the estimated individuals within each population. We did not detect chytrid in any the samples collected. For the three largest populations in the region, we can rule out infections of prevalence greater than 10% with at least 98% confidence. Research at a larger scale is urgently needed to clarify the role of B. dendrobatidis in the decline of this and other amphibians in Italy.

  14. Venomous and poisonous Australian animals of veterinary importance: a rich source of novel therapeutics.

    Science.gov (United States)

    Hardy, Margaret C; Cochrane, Jonathon; Allavena, Rachel E

    2014-01-01

    Envenomation and poisoning by terrestrial animals (both vertebrate and invertebrate) are a significant economic problem and health risk for domestic animals in Australia. Australian snakes are some of the most venomous animals in the world and bees, wasps, ants, paralysis ticks, and cane toads are also present as part of the venomous and poisonous fauna. The diagnosis and treatment of envenomation or poisoning in animals is a challenge and can be a traumatic and expensive process for owners. Despite the potency of Australian venoms, there is potential for novel veterinary therapeutics to be modeled on venom toxins, as has been the case with human pharmaceuticals. A comprehensive overview of envenomation and poisoning signs in livestock and companion animals is provided and related to the potential for venom toxins to act as therapeutics. PMID:25143943

  15. Visualising lymph movement in anuran amphibians with computed tomography.

    Science.gov (United States)

    Hedrick, Michael S; Hansen, Kasper; Wang, Tobias; Lauridsen, Henrik; Thygesen, Jesper; Pedersen, Michael

    2014-09-01

    Lymph flux rates in anuran amphibians are high relative to those of other vertebrates owing to 'leaky' capillaries and a high interstitial compliance. Lymph movement is accomplished primarily by specialised lymph muscles and lung ventilation that move lymph through highly compartmentalised lymph sacs to the dorsally located lymph hearts, which are responsible for pumping lymph into the circulatory system; however, it is unclear how lymph reaches the lymph hearts. We used computed tomography (CT) to visualise an iodinated contrast agent, injected into various lymph sacs, through the lymph system in cane toads (Rhinella marina). We observed vertical movement of contrast agent from lymph sacs as predicted, but the precise pathways were sometimes unexpected. These visual results confirm predictions regarding lymph movement, but also provide some novel findings regarding the pathways for lymph movement and establish CT as a useful technique for visualising lymph movement in amphibians. PMID:25165132

  16. First record of Chaunus achavali (Anura, Bufonidae) from Rio Grande do Sul, Brazil, with a key for the identification of the species in the Chaunus marinus group

    Scientific Electronic Library Online (English)

    Axel, Kwet; Marcos, Di-Bernardo; Raúl, Maneyro.

    2006-12-30

    Full Text Available Chaunus achavali, uma espécie de bufonídeo recentemente descrita e conhecida apenas para o Uruguai, é registrada para o Brasil. Esta espécie é morfologicamente similar a C. ictericus e C. arenarum, sendo que vários espécimes foram rotulados com esses nomes em coleções científicas brasileiras. É desi [...] gnado um lectótipo para C. arenarum. São apresentadas notas de campo sobre C. achavali e uma chave para identificação das espécies do grupo C. marinus. Abstract in english The bufonid toad Chaunus achavali, a recently described species known only from Uruguay, is recorded for Brazil. This species is morphologically similar to C. ictericus and C. arenarum, and several individuals were labeled in Brazilian scientific collections under these taxa. A lectotype of C. arena [...] rum is designated. Additional field notes on C. achavali and a key for the identification of the species in the Chaunus marinus group are presented.

  17. First record of Chaunus achavali (Anura, Bufonidae from Rio Grande do Sul, Brazil, with a key for the identification of the species in the Chaunus marinus group

    Directory of Open Access Journals (Sweden)

    Axel Kwet

    Full Text Available The bufonid toad Chaunus achavali, a recently described species known only from Uruguay, is recorded for Brazil. This species is morphologically similar to C. ictericus and C. arenarum, and several individuals were labeled in Brazilian scientific collections under these taxa. A lectotype of C. arenarum is designated. Additional field notes on C. achavali and a key for the identification of the species in the Chaunus marinus group are presented.Chaunus achavali, uma espécie de bufonídeo recentemente descrita e conhecida apenas para o Uruguai, é registrada para o Brasil. Esta espécie é morfologicamente similar a C. ictericus e C. arenarum, sendo que vários espécimes foram rotulados com esses nomes em coleções científicas brasileiras. É designado um lectótipo para C. arenarum. São apresentadas notas de campo sobre C. achavali e uma chave para identificação das espécies do grupo C. marinus.

  18. Stability analysis of a power system made up of an intermittent renewable energy source directly tied to a conventional rotating power generator

    International Nuclear Information System (INIS)

    A simple power system made up of a conventional rotating power generator in direct connection to an intermittent renewable energy source (with energy or photovoltaic) is modelled on the base of respective functional schemes. The relative variations of the voltage frequency are calculated as an output to an abrupt variation of intermittent tied power and in function of electro-mechanical parameters of the rotating generator (dumping coefficient and inertial rotor coefficient). The stability conditions and the tolerance allowed on the frequency variations are considered in relation to toad service requires. As a consequence, the maximum intermittent power amount, which can be accepted in direct connection, is obtained. For usual conventional rotating machines, the resulting limit is placed in the range of (12-19)% of nominal capacity of power generator

  19. 4MOST fiber feed concept design

    Science.gov (United States)

    Haynes, D. M.; Winkler, R.; Saviauk, Allar; Haynes, R.; Barden, S.; Bellido-Tirado, O.; Bauer, S.; de Jong, Roelof S.; Depagne, E.; Dionies, F.; Ehrlich, K.; Kelz, Andreas; Saunders, W.; Woche, M.

    2014-08-01

    4MOST, the 4m Multi-Object Spectroscopic Telescope, features a 2.5 degree diameter field-of-view with ~2400 fibers in the focal plane that are configured by a fiber positioner based on the tilting spine principle (Echidna/FMOS) arranged in a hexagonal pattern. The fibers feed two types of spectrographs; ~1600 fibers go to two spectrographs with resolution R>5000 and ~800 fibers to a spectrograph with R>18,000. Part of the ongoing optimization of the fiber feed subsystem design includes early prototyping and testing of key components such as fiber connectors and fiber cable management. Performance data from this testing will be used in the 4MOST instrument simulator (TOAD) and 4MOST system design optimization. In this paper we give an overview of the current fiber feed subsystem design, simulations and prototyping plans.

  20. Topical application of a melanotropin analogue to vulgar vitiligo dermo-epidermal minigrafts

    Scientific Electronic Library Online (English)

    A.M., Schwartzmann-Solon; M.A., Visconti; A.M.L., Castrucci.

    1998-12-01

    Full Text Available Human subjects with active vulgar vitiligo do not respond well to autologous dermo-epidermal minigrafting. Eighteen subjects were treated with the a-melanocyte-stimulating hormone (a-MSH) synthetic analogue [Nle4, D-Phe7]-[...] mbol">a-MSH. The hormone (50 µl, 0.4 mM) was applied topically to 30-cm2 lesions in which 29-48 minigrafts had been made. The hormone did not improve the success of the minigrafting and no differences were observed in local or distant repigmentation in treated subjects as compared to the placebo group. Aliquots of 24-h urine concentrated by lyophilization irreversibly darkened toad skins, demonstrating the presence of the analogue. This is the first report of the transdermal delivery of a topically applied melanotropin in living human subjects.

  1. Modelos experimentales de anuros para estudiar los efectos de piretroides / Anuran experimental models to study pyrethroid effects

    Scientific Electronic Library Online (English)

    María F., Izaguirre; Liliana, Marín; María N., Vergara; Rafael C., Lajmanovich; Paola, Peltzer; Víctor H., Casco.

    2006-05-01

    Full Text Available Los ecosistemas acuáticos están cada vez más expuestos a numerosos contaminantes ambientales, como los agroquímicos. En los últimos años se ha observado que los tests de toxicidad sólo evalúan los efectos a corto plazo (mortalidad) y no son suficientes para evaluar los riesgos de los ecosistemas. Po [...] r esta razón, son muy importantes las evaluaciones a largo plazo, ya que permiten estimar la incidencia de estos cambios sobre la biodiversidad y la salud humana. En el presente artículo evaluamos estadísticamente, bajo condiciones de laboratorio, el efecto agudo (mortalidad - supervivencia), las dosis subcrónicas (tasa de crecimiento y desarrollo) y las alteraciones a nivel subcelular e histológico, producidos por el pesticida cipermetrina. Los bioensayos de toxicidad fueron realizados con embriones y larvas de estadios críticos de dos especies regionales de anuros: Physalaemus biligonigerus y Bufo arenarum. Estas especies fueron elegidas debido a su sensibilidad a los biocidas y a su importancia ecológica. Adicionalmente, se realizó un análisis morfológico de los órganos target por microscopía óptica y electrónica, para evaluar el desarrollo de mecanismos adaptativos a las nuevas condiciones desfavorables. Se realizaron en forma complementaria estudios de in situ TUNEL y morfometría. Abstract in english Aquatic ecosystems are increasingly exposed to numerous environmental contaminants, as agrochemicals. In recent years it has been observed that toxicity tests only span short time effects (mortality) but are not sufficient to evaluate the ecosystems risk. For that reason, long time estimations are v [...] ery important as reference to estimate the incidence of those changes over the biodiversity and also on human health. In the present report we statistically analyzed, under laboratory conditions, the acute effect (mortality - survival) and subchronic doses (growth rate and development), as well as the alterations at histological and subcellular level produced by the cypermethrin pesticide. Bioassays on toxicity were carried out with embryos and tadpoles of critical stages of two regional anuran species: Physalaemus biligonigerus and Bufo arenarum. These species were chosen due to their biocides sensibility and ecological importance. Additionally, a morphological analysis of the target organs by optic and electron microscopy was carried on, to determine the development of adaptative mechanisms to the new adverse condition. Complementary studies of in situ TUNEL and morphometry were made.

  2. Lankesterella alencari n. sp., a toxoplasma-like organism in the central nervous system of Amphibia (Protozoa, Sporozoa Lankesterella alencari n. sp., um toxoplasma-like no sistema nervoso central de Amphibia (Protozoa, Sporozoa

    Directory of Open Access Journals (Sweden)

    Sylvio Celso Gonçalves da Costa

    1971-01-01

    Full Text Available Lankesterella alencari n. sp. a Sporozoa that occur in the blood and CNS of the South American frog Leptodactylus acellatus is described. Since the tissue forms of this parasite have been previously reported as belonging to the genus Toxoplasma, we attempted in fection of 2 species of amphibia (Bufo marinus an dLeptodactylus ocellatus with a Toxoplasma strain of human origen; inoculation was by intraperitoneal injection of parasite-containing ascitic fluid from infected mice. Attempt of experimental inoculation of the parasite found in the CNS of L. ocellatus in a highly susceptible host (mice was unsuccessful. These results suggest that Toxoplasma does not occur naturally in the amphibia; be related to Toxoplasma is excluded. The following genera of haematozoa found in brazilian amphibia have been considered briedfly: Haemobartonella, Cytamoeba, Dactylosoma, Hepatozoon and Trypanosoma.Os autores descrevem uma espécie do gênero Lankesterella considerada nova para a ciência, que ocorre com certa freqüência parasitando a rã Leptodactylus ocellatus no Brasil. Como os cistos dêste parasito, encontrados no SNC, foram anteriormente relacionados ao gênero Toxoplasma por outro autor, realizamos uma série de inoculações experimentais para eliminar a hipótese. Tanto as inoculações com amostra de Toxoplasma gondii de origem humana em anfíbios, como as de mascerados de SNC de rã contendo cistos em camundongos, foram negativas. As inoculações de T. gondii em anfíbios foram realizadas em temperatura ambiente que no Rio de Janeiro, na época era 30º-39ºC. Não encontramos, por outro lado, cistos no SNC de anfíbios do gênero Bufo, fato assinalado por outros autores. Realizamos algumas técnicas citoquímicas para melhor caracterização do parasito. Tendo em vista o grande número de hemoparasitos encontrados nas rãs brasileiras e as infecções múltiplas ocorrerem com freqüência, apresentamos também a incidência dêstes parasitos que compreendem os gêneros: Haemobartonella, Cytamoeba, Dactylosoma, Hepatozoon e Trypanosoma. Apresentamos também uma lista de todos os anfíbios examinados, bem como dados sôbre a distribuição geográfica dos hemoparasitos encontrados. Os autores chamam a atenção para o fato de Leptodactylus ocelllatus ser uma rã muito comum no Brasil e utilizada com muita freqüência em trablalhos experimentais de Bioquímica, Fisiologia, Bacteriologia, etc. No caso de infecção intensas por esporozoários os órgãos sofrem lesões extensas e por êste motivo julgamos necessário que em tais trabalhos experimentais êsse parasitismo seja levado em consideração.

  3. Lankesterella alencari n. sp., a toxoplasma-like organism in the central nervous system of Amphibia (Protozoa, Sporozoa) / Lankesterella alencari n. sp., um toxoplasma-like no sistema nervoso central de Amphibia (Protozoa, Sporozoa)

    Scientific Electronic Library Online (English)

    Sylvio Celso Gonçalves da, Costa; Neize de Moura, Pereira.

    Full Text Available Os autores descrevem uma espécie do gênero Lankesterella considerada nova para a ciência, que ocorre com certa freqüência parasitando a rã Leptodactylus ocellatus no Brasil. Como os cistos dêste parasito, encontrados no SNC, foram anteriormente relacionados ao gênero Toxoplasma por outro autor, real [...] izamos uma série de inoculações experimentais para eliminar a hipótese. Tanto as inoculações com amostra de Toxoplasma gondii de origem humana em anfíbios, como as de mascerados de SNC de rã contendo cistos em camundongos, foram negativas. As inoculações de T. gondii em anfíbios foram realizadas em temperatura ambiente que no Rio de Janeiro, na época era 30º-39ºC. Não encontramos, por outro lado, cistos no SNC de anfíbios do gênero Bufo, fato assinalado por outros autores. Realizamos algumas técnicas citoquímicas para melhor caracterização do parasito. Tendo em vista o grande número de hemoparasitos encontrados nas rãs brasileiras e as infecções múltiplas ocorrerem com freqüência, apresentamos também a incidência dêstes parasitos que compreendem os gêneros: Haemobartonella, Cytamoeba, Dactylosoma, Hepatozoon e Trypanosoma. Apresentamos também uma lista de todos os anfíbios examinados, bem como dados sôbre a distribuição geográfica dos hemoparasitos encontrados. Os autores chamam a atenção para o fato de Leptodactylus ocelllatus ser uma rã muito comum no Brasil e utilizada com muita freqüência em trablalhos experimentais de Bioquímica, Fisiologia, Bacteriologia, etc. No caso de infecção intensas por esporozoários os órgãos sofrem lesões extensas e por êste motivo julgamos necessário que em tais trabalhos experimentais êsse parasitismo seja levado em consideração. Abstract in english Lankesterella alencari n. sp. a Sporozoa that occur in the blood and CNS of the South American frog Leptodactylus acellatus is described. Since the tissue forms of this parasite have been previously reported as belonging to the genus Toxoplasma, we attempted in fection of 2 species of amphibia (Bufo [...] marinus an dLeptodactylus ocellatus) with a Toxoplasma strain of human origen; inoculation was by intraperitoneal injection of parasite-containing ascitic fluid from infected mice. Attempt of experimental inoculation of the parasite found in the CNS of L. ocellatus in a highly susceptible host (mice) was unsuccessful. These results suggest that Toxoplasma does not occur naturally in the amphibia; be related to Toxoplasma is excluded. The following genera of haematozoa found in brazilian amphibia have been considered briedfly: Haemobartonella, Cytamoeba, Dactylosoma, Hepatozoon and Trypanosoma.

  4. TEMPORAL AND SPATIAL DISTRIBUTION IN AN ANURAN COMMUNITY IN MUNICIPALITY OF RIO CLARO, SP, BRAZIL = DISTRIBUIÇÃO ESPACIAL E TEMPORAL DE UMA COMUNIDADE DE ANFÍBIOS ANUROS DO MUNICÍPIO DE RIO CLARO, SÃO PAULO, BRASIL

    Directory of Open Access Journals (Sweden)

    Celio Fernando Baptista Haddad

    2003-01-01

    Full Text Available The comprehension of structure and functioning of communities arefundamental for the execution of conservation efforts in forested areas. In the present study we evaluated a community of anurans in a State Forest in Southeast Brazil, emphasizing the reproductive biology of the species. It has been found 21 species, of four families: Bufonidae, Hylidae, Leptodactylidae, and Microhylidae. The species of the family Bufonidae reproduced during the dry and cold season, while other species reproduced only during the wet and warm season of the year. Besides temporal segregation, some species divided the physical environment during reproductive season. Strong temporal and spatial overlap was observed among phylogenetically close species (of the same genus, such as Hyla nana and H. sanborni, Scinax fuscovarius and Scinax sp. (aff. similis, and Leptodactylus fuscus, L. mystacinus, and Leptodactylus sp. (gr. fuscus. In these cases, acoustic differences may be the main factor responsible for thereproductive segregation. Lack of reproductive segregation was observed among species of the genus Bufo, which were found in interespecific amplexus, even with acoustic differences in their advertisement calls. = A compreensão da composição e inter-relações das comunidades faunísticas são fundamentais para a execução de medidas conservacionistas em ambientes florestais. No presente estudo nos avaliamos a comunidade de anfíbios de uma floresta estadual nomunicípio de Rio Claro, SP, com enfoque na biologia reprodutiva. Foram registradas 21 espécies, de quarto famílias: Bufonidae, Hylidae, Leptodactylidae e Microhylidae. As espécies da família Bufonidae reproduziram durante a estação fria e seca do ano e asdemais somente durante a estação quente e chuvosa. Além de segregação temporal, algumas espécies dividiram o ambiente físico durante o período reprodutivo. Acentuada sobreposição temporal e espacial foi observada entre espécies filogeneticamente próximas, como entre Hyla nana e H. sanborni, entre Scinax fuscovarius e Scinax sp. (aff. similis, e entre Leptodactylus fuscus, L. mystacinus, e Leptodactylus sp. (gr. fuscus. Nestes casos, diferenças acústicas podem ter sido o principal fator responsável pela segregação reprodutiva. Ausência de segregação reprodutiva foi observada entre espécies do gênero Bufo, as quais foram vistas em amplexo interespecífico, apesar das diferenças acústicas entre seus cantos de anúncio.

  5. Biochemical biomarkers of sublethal effects in Rhinella arenarum late gastrula exposed to the organophosphate chlorpyrifos.

    Science.gov (United States)

    Sotomayor, Verónica; Chiriotto, Tai S; Pechen, Ana M; Venturino, Andrés

    2015-03-01

    We determined the biochemical and molecular effects of the organophosphate insecticide chlorpyrifos (CPF) in the late gastrula embryonic stage of the South American toad Rhinella arenarum continuously exposed from fertilization (24?h). Our objective was to evaluate these responses as potential biomarkers at low, sublethal levels of the toxicant. We first established the EC50 for embryo arrest in 21.3?mg/L, with a LOEC of 16?mg/L. At 4?mg/L CPF, some embryos were unable to complete the dorsal lip of the blastopore and the yolk plug became blur, probably because of abnormal cell migration. Acetylcholinesterase activity, the specific biomarker for organophosphates, was unaffected by any of the tested concentrations of CPF (2-14?mg/L). In turn, 2?mg/L CPF increased the reduced glutathione levels and inhibited glutathione-S-transferase activity, suggesting an oxidative stress and antioxidant response. Catalase was induced by CPF exposure at higher concentrations (8 and 14?mg/L). We also studied transcription factor c-Fos as a signaling event related to development in early embryogenesis. Analysis of nuclear c-Fos protein showed two bands, both enhanced in embryos exposed to 2 and 8?mg/L CPF. While nuclear Erk protein was practically unaffected, Mek protein levels were induced by the OP. Transcription factor c-Fos may be then linking oxidative stress with developmental alterations observed due to CPF exposure. These molecular and biochemical responses observed in R.?arenarum gastrula at sublethal CPF exposures may replace non-responsive AChE as very early biomarkers in toad gastrula. PMID:25868816

  6. The lateral intercellular space as osmotic coupling compartment in isotonic transport

    DEFF Research Database (Denmark)

    Larsen, E.H.; Willumsen, N.J.

    2009-01-01

    Solute-coupled water transport and isotonic transport are basic functions of low- and high-resistance epithelia. These functions are studied with the epithelium bathed on the two sides with physiological saline of similar composition. Hence, at transepithelial equilibrium water enters the epithelial cells from both sides, and with the reflection coefficient of tight junction being larger than that of the interspace basement membrane, all of the water leaves the epithelium through the interspace basement membrane. The common design of transporting epithelia leads to the theory that an osmotic coupling of water absorption to ion flow is energized by lateral Na+/K+ pumps. We show that the theory accounts quantitatively for steady- and time dependent states of solute-coupled fluid uptake by toad skin epithelium. Our experimental results exclude definitively three alternative theories of epithelial solute-water coupling: stoichiometric coupling at the molecular level by transport proteins like SGLT1, electro-osmosis and a 'junctional fluid transfer mechanism'. Convection-diffusion out of the lateral space constitutes the fundamental problem of isotonic transport by making the emerging fluid hypertonic relative to the fluid in the lateral intercellular space. In the Na+ recirculation theory the 'surplus of solutes' is returned to the lateral space via the cells energized by the lateral Na+/K+ pumps. We show that this theory accounts quantitatively for isotonic and hypotonic transport at transepithelial osmotic equilibrium as observed in toad skin epithelium in vitro. Our conclusions are further developed for discussing their application to solute-solvent coupling in other vertebrate epithelia such as small intestine, proximal tubule of glomerular kidney and gallbladder. Evidence is discussed that the Na+ recirculation theory is not irreconcilable with the wide range of metabolic cost of Na+ transport observed in fluid-transporting epithelia.

  7. Biodiversity assessment at Department of Atomic Energy (DAE) campus, Kalpakkam

    International Nuclear Information System (INIS)

    A rapid assessment of biodiversity in the DAE campus, Kalpakkam was carried out. The entire DAE campus of 3000 acres, at Kalpakkam was divided into four representative plots comprising of different landscapes namely (1) undisturbed area with dense vegetation, (2) building area, (3) water bodies with riparian cover and (4) sandy area with meager vegetation for inventorying of charismatic terrestrial/semi-aquatic fauna viz., Mammals, Birds, Reptiles, Amphibians and Butterflies. For birds, early morning surveys were made whereas for mammals evening and night surveys were followed. Midday sampling was followed for butterflies and other animals. Each plot was surveyed twice in a week over a period of one year (April 07' to March 08'). Totally 128 species of animals were identified during the survey and it has highlighted the potential of biodiversity in the campus. The diversity of butterflies is remarkable. Twenty-two butterfly species were encountered. Frogs, toads, lizards and snakes are also diverse. Five species of frogs and one species of toad were recorded. Lizards are more diverse than snakes. Nine species of lizards were encountered. Calotus versicolor is abundant followed by common skink. Totally five species of snakes were recorded. Among them Common bronzedback and Green Vine Snake were predominant. Seventy species of birds were recorded during the survey period. Black crowned night heron, Common house crow, Great cormorant, Oriental white ibis, Painted stork, rant, Oriental white ibis, Painted stork, Cattle egret, Common mynah are more common. Sixteen species of mammals were encountered during the survey. Wild cattle, Jackal, Jungle cat, Toddy cat, Crested porcupine and Indian civet are the major wildlife found. Indian civet and Crested porcupine are elusive animals that are diminishing from wild and their presence at this campus is an indication of less human intervention. (author)

  8. Increased frequency and severity of developmental deformities in rough-skinned newt (Taricha granulosa) embryos exposed to road deicing salts (NaCl and MgCl2)

    International Nuclear Information System (INIS)

    Road-side aquatic ecosystems in North America are annually polluted with millions of tons of road deicing salts, which threaten the survival of amphibians which live and breed in these habitats. While much is known of the effects of NaCl, little is known of the second most-commonly used deicer, MgCl2, which is now used exclusively in parts of the continent. Here we report that environmentally relevant concentrations of both NaCl and MgCl2 cause increased incidence of developmental deformities in rough-skinned newt hatchlings that developed embryonically in these salts. In addition, we provide some of the first quantification of severity of different deformities, and reveal that increased salt concentrations increase both deformity frequency and severity. Our work contributes to the growing body of literature that suggests salamanders and newts are particularly vulnerable to salt, and that the emerging pollutant, MgCl2 is comparable in its effects to the more traditionally-used NaCl. - Highlights: ? Rough-skinned newt embryos were raised in NaCl and MgCl2 road deicing salts. ? We quantified the frequency and severity of resulting developmental deformities. ? Both salts caused increased frequency and severity of developmental deformities. ? Effects of MgCl2, an emerging stressor, are comparable to traditionally-used NaCl. ? Newts and salamanders may be more susceptible to road salt than frogs and toads. - ad salt than frogs and toads. - Two commonly used road deicing salts, NaCl and MgCl2, caused increased frequency and severity of developmental deformities in rough-skinned newt embryos.

  9. Determination of Aldosterone by Saturation Analysis Using Binding Sites in Mammalian and Amphibian Kidney and Amphibian Bladder: Preliminary Studies

    International Nuclear Information System (INIS)

    High-energy aldosterone- binding sites have been identified in the kidney of toads by incubation of tissue homogenates, or separated nuclei, from saline-loaded animals with different concentrations of d(+)-aldosterone-178 and determination of the free(f)/bound(b) ratio. After adjustments for the component of aldosterone binding which is non-specific and largely unaltered by a change of aldosterone concentration (10-7M or more), a plot of b/f versus bound reveals binding sites with equilibrium constants of 4.2 x 108 litres/mole for kidney nuclei and 8.7 x 108 litres/mole for kidney homogenate. Application of the principles for optimum conditions for a saturation analytic procedure suggest that, apart from the problem of non-specific binding, the use of toad kidney would require prohibitively large quantities of tissue. However, high-energy-binding sites have been identified, by a similar method, in the kidney of rabbit, pig and rat. These have been localized to the medulla (2.6 x 109 litres/mole for pig and 2.4 x 109 litres/mole for rabbit); the renal cortex of both species showed values which were considerably lower. Separate determinations of the association and dissociation constants for rabbit medulla reveal a figure for the equilibrium constant (2.6 x 109 litres/mole) which is similar to that obtained from the Scatchard plot. Using rabbit medulla tissue fragments, we have constructed a standard curve showing a lower detection limit (standard deviation of blank response/slope of response curve) of approximately 15 pg. (author)

  10. Recent records of alien anurans on the Pacific Island of Guam

    Science.gov (United States)

    Christy, M.T.; Clark, C.S.; Gee, D.E., II; Vice, D.; Vice, D.S.; Warner, M.P.; Tyrrell, C.L.; Rodda, G.H.; Savidge, J.A.

    2007-01-01

    Eight anuran species were recorded for the first time in Guam in the period May 2003-December 2005, all apparently the result of arrivals to the island since 2000. Three of the eight species (Rana guentheri, Polypedates megacephalus, and Eleutherodactylus planirostris) had well-established breeding populations by 2005. A further three (Fejevarya cf. livinocharis, Fejervarya cancrivora, and Microhyla pulchra) were recorded from a number of individuals, but it is not known whether these species have established breeding populations. Two species (Kaloula pulchra and Eleutherodactylus coqui) appear to be incidental transportations to the island that have not established. Before 2003, five anuran species, all introductions, had been recorded from Guam. Three of these, Polypedates leucomystax, Pseudacris regilla, and Kaloula picta, were detected on Guam in incoming cargo but destroyed. Two species established: Bufo marinus was deliberately introduced and the Australian hylid Litoria fallax was probably an accidental introduction. Successful establishment of anurans on Guam has increased the risk of frog introductions to nearby islands. By providing additional food sources for the brown tree snake (Boiga irregularis), anuran introductions have increased the chance that B. irregularis might substantially increase in numbers and in turn increase the risk of the snake being accidentally transported to other islands. ?? 2007 by University of Hawai'i Press All rights reserved.

  11. Adjustment of web-building initiation to high humidity: a constraint by humidity-dependent thread stickiness in the spider Cyrtarachne.

    Science.gov (United States)

    Baba, Yuki G; Kusahara, Miki; Maezono, Yasunori; Miyashita, Tadashi

    2014-07-01

    Cyrtarachne is an orb-weaving spider belonging to the subfamily Cyrtarachninae (Araneidae) which includes triangular-web-building Pasilobus and bolas spiders. The Cyrtarachninae is a group of spiders specialized in catching moths, which is thought to have evolved from ordinary orb-weaving araneids. Although the web-building time of nocturnal spiders is in general related to the time of sunset, anecdotal evidence has suggested variability of web-building time in Cyrtarachne and its closely related genera. This study has examined the effects of temperature, humidity, moonlight intensity, and prey (moths) availability on web-building time of Cyrtarachne bufo, Cyrtarachne akirai, and Cyrtarachne nagasakiensis. Generalized linear mixed model (GLMM) have revealed that humidity, and not prey availability, was the essential variable that explained the daily variability of web-building time. Experiments measuring thread stickiness under different humidities showed that, although the thread of Cyrtarachne was found to have strong stickiness under high humidity, low humidity caused a marked decrease of thread stickiness. By contrast, no obvious change in stickiness was seen in an ordinary orb-weaving spider, Larinia argiopiformis. These findings suggest that Cyrtarachne adjusts its web-building time to favorable conditions of high humidity maintaining strong stickiness, which enables the threads to work efficiently for capturing prey. PMID:24916857

  12. Predation of amphibians by carabid beetles of the genus Epomis found in the central coastal plain of Israel

    Directory of Open Access Journals (Sweden)

    Avital Gasith

    2011-05-01

    Full Text Available The genus Epomis is represented in Israel by two species: E. dejeani and E. circumscriptus. In the central coastal plain these species are sympatric but do not occur in the same sites. The objective of this study was to record and describe trophic interactions between the adult beetles and amphibian species occurring in the central coastal plain of Israel. Day and night surveys at three sites, as well as controlled laboratory experiments were conducted for studying beetle-amphibian trophic interaction. In the field we recorded three cases of E. dejeani preying upon amphibian metamorphs and also found that Epomis adults share shelters with amphibians. Laboratory experiments supported the observations that both Epomis species can prey on amphibians. Predation of the three anuran species (Bufo viridis, Hyla savignyi and Rana bedriagae and two urodele species (Triturus vittatus and Salamandra salamandra infraimmaculata is described. Only E. dejeani consumed T. vittatus. Therefore, we conclude that the two species display a partial overlap in food habit.

  13. Relacionamento entre anfíbios anuros e bromélias da restinga de Regência, Linhares, Espírito Santo, Brasil Relationship between anuran amphibians and bromeliads of the sandy coastal plain of Regência, linhares, Espírito Santo, Brazil

    Directory of Open Access Journals (Sweden)

    José Alberto P. Schineider

    Full Text Available Some anuran amphibians use the bromeliads during the entire life cycle and others only as diurnal shelter. At the sandy coastal plain of Linhares, State of Espírito Santo, Southeastern Brazil, 676 bromeliads were examined, of which 303 of Aechmea blanchetiana (Baker L. B. Smith., 1955, 287 of Aechmea nudicaulis (L. Griseb., 1864, and 86 of Vrisea procera (Mart. Ex Schult. f. Wittm, 1891. The morphometric and physical-chemical analysis of different bromeliads evidenced variations among plants. During the period sampled, six anuran species were found inside the plant axils. The hylid frog Phyllodytes luteolus (Wied, 1824 was the most abundant species (260 specimens. Its abundance was higher in the epiphyte bromeliad Vrisea procera. Phyllodytes luteolus had higher occurrences in bromeliads located at a transitional area between open and under the shrub vegetation. Specimens of Scinax alterus (Lutz, B., 1973 and Aparasphenodon brunoi Miranda-Ribeiro, 1920, were more frequent mainly in transitional areas; Bufo granulosus Spix, 1824 occurred in open and transitional areas, whereas Gastrotheca fissipis (Boulenger, 1888 and Leptodactylus fuscus (Schneider, 1799 were found only in bromeliads located in open areas.

  14. Relacionamento entre anfíbios anuros e bromélias da restinga de Regência, Linhares, Espírito Santo, Brasil / Relationship between anuran amphibians and bromeliads of the sandy coastal plain of Regência, linhares, Espírito Santo, Brazil

    Scientific Electronic Library Online (English)

    José Alberto P., Schineider; Rogério L., Teixeira.

    2001-11-27

    Full Text Available [...] Abstract in english Some anuran amphibians use the bromeliads during the entire life cycle and others only as diurnal shelter. At the sandy coastal plain of Linhares, State of Espírito Santo, Southeastern Brazil, 676 bromeliads were examined, of which 303 of Aechmea blanchetiana (Baker) L. B. Smith., 1955, 287 of Aechm [...] ea nudicaulis (L.) Griseb., 1864, and 86 of Vrisea procera (Mart. Ex Schult. f.) Wittm, 1891. The morphometric and physical-chemical analysis of different bromeliads evidenced variations among plants. During the period sampled, six anuran species were found inside the plant axils. The hylid frog Phyllodytes luteolus (Wied, 1824) was the most abundant species (260 specimens). Its abundance was higher in the epiphyte bromeliad Vrisea procera. Phyllodytes luteolus had higher occurrences in bromeliads located at a transitional area between open and under the shrub vegetation. Specimens of Scinax alterus (Lutz, B., 1973) and Aparasphenodon brunoi Miranda-Ribeiro, 1920, were more frequent mainly in transitional areas; Bufo granulosus Spix, 1824 occurred in open and transitional areas, whereas Gastrotheca fissipis (Boulenger, 1888) and Leptodactylus fuscus (Schneider, 1799) were found only in bromeliads located in open areas.

  15. The effect of sound level, temperature and dehydration on the brainstem auditory evoked potential in anuran amphibians.

    Science.gov (United States)

    Carey, M B; Zelick, R

    1993-11-01

    Brainstem auditory evoked potentials (BAEPs) were used to examine the effects of sound level, temperature, and dehydration on the auditory pathway of three species of anuran amphibians: Rana pipiens, Bufo americanus and B. terrestris. BAEP latency, amplitude and a measure of threshold were determined for all stimulus and test conditions. Threshold values obtained with this technique were similar to other neural measures of threshold in anurans, and were stable for repeated measures within 12 h and over three days. Transient changes in temperature caused non-linear changes in BAEP threshold and latency. Above 20 degrees C small threshold shifts were elicited, while below 20 degrees C we observed rapid deterioration of threshold. Animals acclimated to a cold temperature (14 degrees C) were acoustically less sensitive than warm (21 degrees C) animals, even when both groups were tested at colder temperatures. Because peripheral components of the BAEP were most affected by both transient and acclimation (longer term) cooling and warming, the sensory epithelium appears to be the most temperature-sensitive component of the auditory pathway. Dehydrated frogs showed no auditory dysfunction until a critical level of dehydration was reached. More dehydration-resistant species (B. terrestris and B. americanus) were less susceptible to BAEP degradation near their critical dehydration level. PMID:8294266

  16. Microcosm investigations of stormwater pond sediment toxicity to embryonic and larval amphibians: Variation in sensitivity among species

    International Nuclear Information System (INIS)

    Stormwater ponds have become common features of modern development and often represent significant amounts of open space in urbanized areas. Although stormwater ponds may provide habitat for wildlife, factors responsible for producing variation in wildlife use of ponds have received limited attention. To investigate the role of variation in species tolerances of pollutants in structuring pond-breeding amphibian assemblages, we exposed species tolerant (Bufo americanus) and not tolerant (Rana sylvatica) of urbanization to pond sediments in laboratory microcosms. Pond microcosms had elevated sediment metal levels and chloride water concentrations. Among R. sylvatica embryos, exposure to pond sediments resulted in 100% mortality. In contrast, B. americanus embryos and larvae experienced only sublethal effects (i.e., reduced size at metamorphosis) due to pond sediment exposure. Our results suggest variation in pollutant tolerance among early developmental stages of amphibians may act in concert with terrestrial habitat availability to structure amphibian assemblages associated with stormwater ponds. - Variation among species in sensitivity to pollutants can influence stormwater pond amphibian assemblages

  17. Species-and stage-specific differences in trace element tissue concentrations in amphibians: implications for the disposal of coal-combustion wastes

    International Nuclear Information System (INIS)

    Information on species-and stage-specific patterns of contaminant accumulation is generally lacking for amphibians, yet such information could provide valuable knowledge on how amphibians interact with contaminants. We assessed concentrations of As, Cd, Cu, Ni, Pb, Se, Sr, and Zn in whole bodies of larval, recently metamorphosed, and adult life stages in Bufo terrestris and Rana sphenocephala from a site that currently receives coal combustion waste (CCW) discharge, a site where CCW was formerly discharged that has undergone natural attenuation for 30 years, and a nearby reference site. For the majority of elements (As, Cd, Cu, Ni, Pb, Zn), concentrations were highest in larvae, but Se and Sr concentrations remained elevated in later life stages, likely because these elements are S and Ca analogs, respectively, and are thus retained throughout structural changes during metamorphosis. Element concentrations were generally higher in B. terrestris than in R. sphenocephala. Concentrations of As, Se, and Sr were up to 11-35 times higher in metamorphs emigrating from CCW-polluted wetlands compared to unpolluted wetlands, suggesting metamorphosed amphibians can transport trace elements from aquatic disposal basins to nearby uncontaminated terrestrial habitats. In addition, anurans utilizing naturally revegetated sites up to 30 years after CCW disposal ceases are exposed to trace elements, although to a lesser degree than sites where CCW is currently discharged. - Results sugCCW is currently discharged. - Results suggest that metamorphosed amphibians can transport trace elements from aquatic disposal basins to non-contaminated habitats

  18. Influence of land use on metal concentrations in playa sediments and amphibians in the Southern High Plains

    International Nuclear Information System (INIS)

    The Southern High Plains (SHP) is a semi-arid region in which playa wetlands are the focal points of biodiversity. Playas are highly influenced by surrounding land use. Most of the SHP is in agricultural production (primarily cotton) with a history of arsenic-containing herbicide use. Metals influence reproduction and development in amphibians. We analyzed metal residues in playa sediment and whole body tissue of Spea spp. and Bufo cognatus metamorphs from two land uses: cropland and native grassland. Cd and Ni concentrations in B. cognatus tissues differed between land uses. Metal concentrations in Spea spp. tissues did not differ between land uses. Ba was higher in Spea spp. than B. cognatus collected from the same grassland playas, indicating differential habitat use. No correlations between sediment and tissue concentrations were found. Land use appeared to have little influence on metal concentrations and levels were below those known to cause effects in amphibians. - Land use surrounding playas has little effect on metal concentrations in sediments

  19. Amphibian chytrid fungus (Batrachochytrium dendrobatidis) in coastal and montane California, USA Anurans

    Science.gov (United States)

    Fellers, Gary M.; Cole, Rebecca A.; Reinitz, David M.; Kleeman, Patrick M.

    2011-01-01

    We found amphibian chytrid fungus (Bd = Batrachochytrium dendrobatidis) to be widespread within a coastalwatershed at Point Reyes National Seashore, California and within two high elevation watersheds at Yosemite NationalPark, California. Bd was associated with all six species that we sampled (Bufo boreas, B. canorus, Pseudacris regilla, Ranadraytonii, R. sierrae, and Lithobates catesbeianus). For those species sampled at 10 or more sites within a watershed, thepercentage of Bd-positive sites varied from a low of 20.7% for P. regilla at one Yosemite watershed to a high of 79.6% forP. regilla at the Olema watershed at Point Reyes. At Olema, the percent of Bd-positive water bodies declined each year ofour study (2005-2007). Because P. regilla was the only species found in all watersheds, we used that species to evaluatehabitat variables related to the sites where P. regilla was Bd-positive. At Olema, significant variables were year, length ofshoreline (perimeter), percentage cover of rooted vegetation, and water depth. At the two Yosemite watersheds, waterdepth, water temperature, and silt/mud were the most important covariates, though the importance of these three factorsdiffered between the two watersheds. The presence of Bd in species that are not declining suggests that some of theamphibians in our study were innately resistant to Bd, or had developed resistance after Bd became established.

  20. Radiation-induced changes of the developing nervous system of amphibians

    International Nuclear Information System (INIS)

    The nervous system of amphibians (Xenopus laevis and Bufo) is of an outstanding sensitivity against irradiation in the early periods of its tissue induction and development. This is descriptively shown by various pathological disturbances. Irradiated series showed a protracted course of development. The brains obtains lower relative weights and diminished absolute lengths although the body weight remained nearly constant. The distribution of pigmentation in the brains of treated animals was changed. This indicated radiation-induced disturbances. Further, the significance of pigmentation pattern for a distinct evaluation of histological effects is also confirmed by a coincidence between the gross visible anomalies of the brain and the number of pigment-sites. Examples of malformation are given by aplasias, hypoplasias, hyperplasias up to cases of cyclopia. In the peripheral nervous system of Xenopus the neuromuscular junctions of the musculus interhyoideus were examined. The majority of neural endplates in the irradiated cases showed a loss of Schwann cells. As a consequence a diffusion of the transmitter acetylcholine in the endplate-region must be suggested. Accordingly, the morphological compensation reaction was seen in a thickening and sprouting. (orig.)

  1. Revision of Neotropical aphrophorine spittlebugs, part 2: tribe Orthoraphini (Hemiptera, Cercopoidea).

    Science.gov (United States)

    Hamilton, K G Andrew

    2013-01-01

    The tribe Orthoraphini is validated by diagnosis to include the new-world fauna of Orthorapha Westwood with 21 species from Brazil and 2 newly recorded from Bolivia, including 9 new species: boliviana from an unknown locality in Bolivia and decorata, inscripta, inflata, invidia, irregularis, oculata, sagittata and sphaerata from Brazil. There are also 10 new combinations from Lepyronia Amyot & Serville: bufo Walker; concinna Stål, frontalis Stål, fusconotata Stål, geminata Jacobi, obscurata Amyot & Serville, obliqua Jacobi, quadrimaculata Lallemand, rana Walker and subfasciata Amyot & Serville. Keys are presented to the new-world species and 3 subgenera, including Lepyronoxia Melichar, stat.nov. (= Balsana Metcalf, syn.nov.) and Balsania subg.nov. In addition, the tribe contains 15 genera of old-world Aphrophorinae with an estimated 290 species from Pacific islands; of these, the previously undescribed male genitalia from 25 species in 8 genera are illustrated and antennal characters for Orthorapha and 14 Pacific island genera of Orthoraphini are compared to those of Cloviini, Philaenini and Aphrophorini. This is the first tribe of Cercopoidea to be described as limited to the Southern Hemisphere. PMID:26106685

  2. Levels of sparganum infections and phylogenetic analysis of the tapeworm Spirometra erinaceieuropaei sparganum in wild frogs from Henan Province in central China.

    Science.gov (United States)

    Wei, T; Zhang, X; Cui, J; Liu, L N; Jiang, P; Wang, Z Q

    2015-07-01

    Sparganosis is a serious food-borne parasitic zoonosis caused by infection with Spirometra spargana. The prevalence of sparganum infection in wild frogs (Rana nigromaculata, R. limmochari, R. temporaria and Bufo gargarizans) was investigated in Henan Province of central China during 2008-2012. Of 3482 caught wild frogs, 565 (16.23%) were found to be infected with plerocercoids (spargana) of the genus Spirometra. Spargana were found in 14.85% (320/2155) of R. nigromaculata, 20.82% (233/1119) of R. limmochari and 10.91% (12/110) of R. temporaria frogs. However, no sparganum was found in B. gargarizans. To investigate the phylogenetic position of collected spargana, three mitochondrial DNA (mtDNA) regions, namely cytochrome c oxidase subunits 1 and 3 (cox1 and cox3), and NADH dehydrogenase subunit 4 (nad4), were amplified, sequenced and analysed. Sequences of cox1, cox3 and pnad4 were 417, 390 and 578 bp in length, respectively. The base composition of cox1, cox3 and pnad4 were generally AT rich with a mean of 63.5%, 68.3% and 67% AT, respectively. Phylogenetic analysis showed that all the sparganum isolates in Henan Province represented Spirometra erinaceieuropaei and were a well-supported clade. These findings demonstrated clearly the usefulness of the three mtDNA sequences for molecular identification and population genetics studies of S. erinaceieuropaei spargana of human and animal health significance. PMID:26017331

  3. Época reproductiva y distribución geográfica del sapo  Incilius aucoinae (Bufonidae en Golfito, Costa Rica

    Directory of Open Access Journals (Sweden)

    Susy Segura-Solís

    2009-11-01

    Full Text Available Se estudian algunos aspectos de la biología reproductiva del sapo Incilius aucoinae en una población en el río Cañaza, Golfito, Costa Rica; en una sección de 360 m aguas arriba dividida en 36 sectores de 10 m. La duración del estudio con adultos fue de cuatro años, con muestreos en enero de 1995, 1997, 1998 (excepto marzo y enero de 1999; los renacuajos se estudiaron en cuatro días de 1997. Se marcaron 443 machos (con 315 reobservaciones y 7 hembras (no fueron recapturadas. Un individuo fue recapturado en todos los periodos de estudio, lo que indica que por los menos sobreviven a 5 épocas reproductivas. La época reproductiva corresponde a los meses secos, de diciembre a abril. En la época reproductiva de 1997 se encontró más individuos y menos en 1995; el sector 6 es el que tiene más machos y el 4 menos; la mayor cantidad de machos se encontró en sectores con vegetación semiabierta, los sectores con mayor cobertura vegetal tienen menos; febrero es el mes con mayor abundancia de machos, con valores intermedios en diciembre y enero, y con muy pocos individuos en marzo y abril. En todos los meses, excepto febrero, la abundancia fue mayor donde había playones. Este sapo se reproduce en la época seca, y en el sitio reproductivo las hembras apenas entran a reproducirse. Se da una relación de sexos de casi solo machos, pues solo hubo 7 hembras observadas, y sorprende los cambios de distribución entre el día y la noche en los renacuajos.Reproductive period and geographic distribution of the toad Incilius aucoinae in Golfito, Costa Rica. The biology of neotropical amphibians is not well known. Some toad species of the Bufonidae family are common, thus allowing the study of their populations. We studied a population in río Cañaza, Golfito, Costa Rica, in a sector 360 m upstream of Barrio Ureña, divided in 36 sectors of 10 m. The study was carried out for five years, but taking samples of adults in January 1995, 1997, 1998 (except March, and 1999. We also studied tadpoles during four days in 1997. In total, 443 males and 7 females were marked, with 315 males recaptured and no females. Females are bigger (91.1 mm than males (61.3 mm. Most recaptured individuals occurred in the same or adjacent sectors, with a maximum movement of 28 sectors. One individual was recaptured repeatedly in all the samples. This indicates that they survived at least five reproductive cycles. The reproductive cycle takes place during the dry season, between December and April. We found more individuals during the reproductive cycle of 1997 and less during 1995. Sector 6 had the most number of males and sector number 4 had the least. Sectors with semi-open vegetation had more males compared to sectors with more forest cover. February is the month with the highest abundance of males. There are intermediate values in December and January, and fewer individuals in March and April. In every month, except February, the abundance of individuals was greater where there were beaches. Tadpoles were found both during the day and night in the 31 river sectors, but it was less likely to find tadpoles in the river section during the night. During the day all tadpoles were found scattered around the river, at night they congregated near river margins. The reproductive cycle of this toad occurs during the dry season and females are present only in the reproductive season, resulting in an almost only male sex ratio (only seven females were found. Males can reproduce at least in 5 reproductive cycles, and -unexpectedly- day and night distribution of tadpoles varies. Rev. Biol. Trop. 57 (Suppl. 1: 301-311. Epub 2009 November 30.

  4. Época reproductiva y distribución geográfica del sapo  Incilius aucoinae (Bufonidae) en Golfito, Costa Rica

    Scientific Electronic Library Online (English)

    Susy, Segura-Solís; Federico, Bolaños.

    2009-11-01

    Full Text Available Se estudian algunos aspectos de la biología reproductiva del sapo Incilius aucoinae en una población en el río Cañaza, Golfito, Costa Rica; en una sección de 360 m aguas arriba dividida en 36 sectores de 10 m. La duración del estudio con adultos fue de cuatro años, con muestreos en enero de 1995, 19 [...] 97, 1998 (excepto marzo) y enero de 1999; los renacuajos se estudiaron en cuatro días de 1997. Se marcaron 443 machos (con 315 reobservaciones) y 7 hembras (no fueron recapturadas). Un individuo fue recapturado en todos los periodos de estudio, lo que indica que por los menos sobreviven a 5 épocas reproductivas. La época reproductiva corresponde a los meses secos, de diciembre a abril. En la época reproductiva de 1997 se encontró más individuos y menos en 1995; el sector 6 es el que tiene más machos y el 4 menos; la mayor cantidad de machos se encontró en sectores con vegetación semiabierta, los sectores con mayor cobertura vegetal tienen menos; febrero es el mes con mayor abundancia de machos, con valores intermedios en diciembre y enero, y con muy pocos individuos en marzo y abril. En todos los meses, excepto febrero, la abundancia fue mayor donde había playones. Este sapo se reproduce en la época seca, y en el sitio reproductivo las hembras apenas entran a reproducirse. Se da una relación de sexos de casi solo machos, pues solo hubo 7 hembras observadas, y sorprende los cambios de distribución entre el día y la noche en los renacuajos. Abstract in english Reproductive period and geographic distribution of the toad Incilius aucoinae in Golfito, Costa Rica. The biology of neotropical amphibians is not well known. Some toad species of the Bufonidae family are common, thus allowing the study of their populations. We studied a population in río Cañaza, Go [...] lfito, Costa Rica, in a sector 360 m upstream of Barrio Ureña, divided in 36 sectors of 10 m. The study was carried out for five years, but taking samples of adults in January 1995, 1997, 1998 (except March), and 1999. We also studied tadpoles during four days in 1997. In total, 443 males and 7 females were marked, with 315 males recaptured and no females. Females are bigger (91.1 mm) than males (61.3 mm). Most recaptured individuals occurred in the same or adjacent sectors, with a maximum movement of 28 sectors. One individual was recaptured repeatedly in all the samples. This indicates that they survived at least five reproductive cycles. The reproductive cycle takes place during the dry season, between December and April. We found more individuals during the reproductive cycle of 1997 and less during 1995. Sector 6 had the most number of males and sector number 4 had the least. Sectors with semi-open vegetation had more males compared to sectors with more forest cover. February is the month with the highest abundance of males. There are intermediate values in December and January, and fewer individuals in March and April. In every month, except February, the abundance of individuals was greater where there were beaches. Tadpoles were found both during the day and night in the 31 river sectors, but it was less likely to find tadpoles in the river section during the night. During the day all tadpoles were found scattered around the river, at night they congregated near river margins. The reproductive cycle of this toad occurs during the dry season and females are present only in the reproductive season, resulting in an almost only male sex ratio (only seven females were found). Males can reproduce at least in 5 reproductive cycles, and -unexpectedly- day and night distribution of tadpoles varies. Rev. Biol. Trop. 57 (Suppl. 1): 301-311. Epub 2009 November 30.

  5. Do lower vertebrates suffer from motion sickness?

    Science.gov (United States)

    Lychakov, Dmitri

    The poster presents literature data and results of the author’s studies with the goal to find out whether the lower animals are susceptible to motion sickness (Lychakov, 2012). In our studies, fish and amphibians were tested for 2 h and more by using a rotating device (f = 0.24 Hz, a _{centrifugal} = 0.144 g) and a parallel swing (f = 0.2 Hz, a _{horizontal} = 0.059 g). The performed studies did not revealed in 4 fish species and in toads any characteristic reactions of the motion sickness (sopite syndrome, prodromal preparatory behavior, vomiting). At the same time, in toads there appeared characteristic stress reactions (escape response, an increase of the number of urinations, inhibition of appetite), as well as some other reactions not associated with motion sickness (regular head movements, eye retractions). In trout fry the used stimulation promoted division of the individuals into the groups differing by locomotor reaction to stress, as well as the individuals with the well-expressed compensatory reaction that we called the otolithotropic reaction. Analysis of results obtained by other authors confirms our conclusions. Thus, the lower vertebrates, unlike mammals, are immune to motion sickness either under the land conditions or under conditions of weightlessness. On the basis of available experimental data and theoretical concepts of mechanisms of development the motion sickness, formulated in several hypotheses (mismatch hypothesis, Traisman‘ s hypothesis, resonance hypothesis), there presented the synthetic hypothesis of motion sickness that has the conceptual significance. According to the hypothesis, the unusual stimulation producing sensor-motor or sensor-sensor conflict or an action of vestibular and visual stimuli of frequency of about 0.2 Hz is perceived by CNS as poisoning and causes the corresponding reactions. The motion sickness actually is a byproduct of technical evolution. It is suggested that in the lower vertebrates, unlike mammals, there is absent the hypothetical center of subjective «nauseating» sensations; therefore, they are immune to the motion sickness. This work was partly supported by Russian grant RFFI 14-04-00601.

  6. Temporal variation and size class distribution in a hepertological assemblage from Córdoba, Argentina

    Directory of Open Access Journals (Sweden)

    Martori, Ricardo

    2005-05-01

    Full Text Available Desde el punto de vista de la conservación, conocer la abundancia, la diversidad, y los patrones de actividad de un ensamble herpetológico son medulares para comprender la dinámica de la comunidad y el modo de cómo es utilizado el hábitat. En este proyecto propusimos cuatro hipótesis nulas: 1 La frecuencia de captura de cada una de las especies será similar en los dos años relevados. 2 La frecuencia de capturas de cada especie es similar durante los meses estudiados. 3 La actividad de cada especie es similar a la actividad del resto del ensamble. 4 Las proporciones de cada grupo etario de cada especie se mantienen constantes en el tiempo. Durante este estudio fueron colectadas diecinueve especies, diez especies de Amphibia distribuidas en cuatro familias y nueve especies de Squamata distribuidas en siete familias. En hábitats relativamente complicados que poseen una estructura vegetal compleja y presentan patrones de actividad herpetológica irregular, el uso de trampas de caída resulta uno de los pocos métodos eficientes para la evaluación de la actividad de animales terrestres. El uso de trampas de caída es un método efectivo para realizar inventarios herpetológicos pero los resultados deben ser tratados con precaución porque este método captura algunas especies más fácilmente que otras. Los principales resultados obtenidos por este estudio fueron: La hipótesis 1 fue rechazada, para todas las especies exceptuando a Mabuya dorsivittata, que mostró frecuencias de actividad similares en ambos años, la hipótesis 2 también fue rechazada porque todas las especies mostraron significativas diferencias de actividad temporal. Las especies más variables fueron Odontophrynus americanus y Bufo fernandezae; la más constante Pantodactylus schreibersi. La tercera hipótesis fue rechazada para todas las especies salvo Elachistocleis bicolor que presentó un patrón de actividad similar al ensamble. La hipótesis 4 fue rechazada, los grupos etarios de cada especie cambió temporalmente debido al reclutamiento y el período de reclutamiento varió en y entre especies. Durante el primer período el índice de diversidad mayor se registró en abril 1999 (5.46, durante el segundo período de estudio el mayor índice de diversidad se registró en enero 2000. Este estudio muestra la importancia de los estudios temporalmente extensos y enfatiza la importancia de comprender la variación temporal de la fenología, diversidad y patrones de actividad de los ensambles herpetológicos. From a conservationist perspective, knowledge of the abundance, diversity, and activity patterns of a herpetological assemblage is essential to understand community dynamics and habitat utilization. We proposed four null hypotheses regarding the dynamics of an assemblage of amphibians and reptiles from Argentina: 1 The capture frequency of each species studied is similar during the two years; 2 The capture frequency of each species is similar in every month of each period; 3 The activity of each species is similar to that of every other species and 4 The proportion of each size class for each species is similar throughout the year. During the study, nineteen species were collected: ten species of Amphibia belonging to four families, and nine species of Squamata, distributed among seven families. In relatively complex habitats, with dense vegetation and very irregular herpetological activity, the pitfall method is one of the few efficient ways to evaluate terrestrial animal activity. Pitfall traps are an effective method to perform herpetological inventories, but results must be reported with caution because traps capture some species more easily than others. The main results of this study were: Hypothesis 1 was rejected for all species except Mabuya dosivittata, which showed similar frequencies during both years. Hypothesis 2 was rejected, as all species showed significant seasonal differences. The most variable species were Bufo fernandezae and Odontophrynus americanus; the most constant was Pantodactylus schreibersi. Hy

  7. Consideracões sobre a natureza, desenvolvimento e transmissão de Cytamoeba bacterifera Labbé, 1894 de Leptodactylus ocellatus / Considerations about the nature, development and transmission of Cytamoeba bacterifera Labbé, 1894 from Leptodactylus ocellatus

    Scientific Electronic Library Online (English)

    Maria Auxiliadora de, Sousa; Eliane Guimarães, Freire.

    Full Text Available Com o objetivo de fornecer dados para o esclarecimento do controvertido problema da natureza de Cytamoeba bacterifera freqüentemente encontrada nos eritrócitos de Leptodactylus ocellatus, realizamos alguns testes citoquímicos. Demonstramos a presença do ácido ribonucleico e polissacarídeos não diger [...] íveis pela ptialina em sua estrutura. Com o método de Feulgen, teste de referência para a caracterização do ácido desoxirribonucleico, obtivemos principlemnte resultados negativos; porém, um parasito com fraca e difusa positividade e algumas reações duvidosas também foram encontrados. Ao emrpegarmos o Verde Metila-Pironina, mesmo após o tratamento pela ribonuclease, e o Azul de Toluidina, também depois da ação desta enzima, não conseguimos confimar a presença de ADN. Como os elementos constituintes de C. bacterifera são minúsculos e, às vezes, não evidenciáveis, é possível que seu teor de ADN, porventura existente, seja muito pequeno e, conseqüentemente, de difícil demonstração por métodos cujos resultados são observados sob microscopia ótica, além de poder ficar facilmente encoberto por outras substâncias. Não estamos propensos a admitir uma provável natureza virótica para Cytamoeba baseados, principalmente, em alguns de seus aspectos estruturais (figs. 8, 15, 17 e 18) e na ausência de alteração no núcleo das células parasitadas. Apesar de não termos comprovado a presença de ADN, achamos possível que C. bacterifera seja um aglomerado intracitoplasmático de organismos modificados, cujas dimensões situam-se nas proximidades do limite de resolução do microscópio ótico, relacionados com as bactérias, assim como são, por exemplo, os Clamídios e as Riquétsias. Observamos o desenvolvimento de Cytamoeba em rã mantida em cativeiro por três meses e semanalmente examinada; constatamos decréscimo paulatino da parasitemia inicial e também que os seus tipos estruturais e medidas não estavam relacionadas com a etapa da infecção. Não conseguimos transmitir, por inoculação intra-peritoneal, Cytamoeba de L. ocellatus para Bufo crucifer. Abstract in english In view to furnish data to elucita the controversial problem of the nature of Cytamoeba bacterifera, which it is often found in erythrocytes of the frog Leptodactylus ocellatus, we have done some cytochemical tests. We displayd in its structure the contents of RNA and polysaccharides that do not und [...] ergo digestion by ptyalin. With the Feulgen's method we mainly obtained negative results, but one parasite showed a faintly diffused positivity and a few doubtful reaction were also observed. When we employed the Methyl Green-Pyronin, even after the ribonuclease treatment, and the Toluidin Blue, likewise subsequent to the activity of this enzime, we did not evidence the DNA. Taking into account that the components of C. bacterifere are usually very small and sometimes undiscernible, it is probable that their contents of DNA, perhaps existent, would be difficultly demonstrated under the light microscope, and also that it would be easily dissimulated by other substances. We do not believe in a viral nature of Cytamoeba mainly regarding some aspects of its structure (figs. 8, 15, 17 and 18) and the absence of damage on the nucleous of the infected cells. Although we did not prove the presence of DNA, we think that it is possible that C. bacterifera is an intracytoplasmic clump of modified organisms wich sizes are just within the nearness of th limit of visibility with optical microscopes, related with the bacteria, such as are, by exemple, the Chlamydiae and Rickettsiae. The development of Cytamoeba was followed in a frog maintained int he laboratory during three months and weekly examined; we observed progressive decrease of the parasitismo. Its structural types and sizes were not related with the phasis of the infection. We did not get transmission by intraperitonela inoculation of C. bacterifera from L. ocellatus to Bufo crucifer.

  8. Fauna de anuros en la ciudad de Salta, Argentina

    Scientific Electronic Library Online (English)

    Rebeca, Acosta; Rosa Vera, Mesones; Alejandro, Núñez.

    2005-09-01

    Full Text Available La pérdida y transformación del hábitat generado por actividades humanas es una de las principales causas de disminución de biodiversidad. Los anfibios constituyen un grupo en franca declinación a nivel global debido a múltiples motivos, entre ellos la reducción de sus hábitats; sin embargo, se obse [...] rvan poblaciones de anuros en ambientes altamente antropizados como las ciudades. El objetivo del trabajo fue recabar información de base ecológicamente necesaria para comprender la distribución de las comunidades de anuros en estos ambientes. Para ello, se efectuó el inventario de la fauna de anuros del ejido urbano de la Ciudad de Salta, Argentina, con una población estimada en 502 316 habitantes. Se diseñó el muestreo por ambientes, caracterizándolos en función del tipo de infraestructura urbana y su ubicación por zonas geográficas. La identificación de las especies se realizó a partir de técnicas de encuentro visual y transecta auditiva, abarcando la temporada reproductiva 2002-2003. Se detectaron tres familias, siete géneros y doce especies, observando una disminución de la riqueza desde los bordes hacia el centro del ejido urbano. El índice de similitud entre zonas geográficas fue mayor para el par Este-Oeste (94.7), mientras que el menor fue para el par Sur-Oeste (33.3). Bufo arenarum fue la especie presente en todos los ambientes caracterizados, mientras que Hyla andina y Odontophrynus americanus son las especies con distribución más restringida y por lo tanto más vulnerables. Con los datos obtenidos, se generó un mapa de distribución potencial de las especies en la ciudad analizando las posibles causas de las diferencias observadas. Abstract in english Anuran fauna from Salta City, Argentina. The loss and transformation of habitat by anthropogenic activities is one of the main causes of biodiversity decrease. Amphibians are declining all over the world and one of the causes of this decline is thought to be habitat reduction. However, there are anu [...] ran populations in highly disturbed habitats, like cities. This study presents the ecological baseline needed to understand anuran communities in urban environments, for Salta City, Argentina (ca. 502 000 inhabitants). The sample was stratified by environments defined by infrastructure and geographic location. The species were identified by visual encounter techniques and by auditory transect during the 2002-2003 reproductive period. Three families, seven genera and twelve species were recorded and the species richness decreased from city border to center. Similarity index values among geographic areas was higher East-West (94.7) than South-West (33.3). Bufo arenarum was the only species recorded in all environments. Hyla andina and Odontophrynus americanus had a restricted distribution and are here considered vulnerable. The border effect can explain some distribution pattern in these populations. A map of the potential distribution of recorded species for Salta is provided. Rev. Biol. Trop. 53(3- 4): 569-575. Epub 2005 Oct 3.

  9. Fauna de anuros en la ciudad de Salta, Argentina

    Directory of Open Access Journals (Sweden)

    Rebeca Acosta

    2005-09-01

    Full Text Available La pérdida y transformación del hábitat generado por actividades humanas es una de las principales causas de disminución de biodiversidad. Los anfibios constituyen un grupo en franca declinación a nivel global debido a múltiples motivos, entre ellos la reducción de sus hábitats; sin embargo, se observan poblaciones de anuros en ambientes altamente antropizados como las ciudades. El objetivo del trabajo fue recabar información de base ecológicamente necesaria para comprender la distribución de las comunidades de anuros en estos ambientes. Para ello, se efectuó el inventario de la fauna de anuros del ejido urbano de la Ciudad de Salta, Argentina, con una población estimada en 502 316 habitantes. Se diseñó el muestreo por ambientes, caracterizándolos en función del tipo de infraestructura urbana y su ubicación por zonas geográficas. La identificación de las especies se realizó a partir de técnicas de encuentro visual y transecta auditiva, abarcando la temporada reproductiva 2002-2003. Se detectaron tres familias, siete géneros y doce especies, observando una disminución de la riqueza desde los bordes hacia el centro del ejido urbano. El índice de similitud entre zonas geográficas fue mayor para el par Este-Oeste (94.7, mientras que el menor fue para el par Sur-Oeste (33.3. Bufo arenarum fue la especie presente en todos los ambientes caracterizados, mientras que Hyla andina y Odontophrynus americanus son las especies con distribución más restringida y por lo tanto más vulnerables. Con los datos obtenidos, se generó un mapa de distribución potencial de las especies en la ciudad analizando las posibles causas de las diferencias observadas.Anuran fauna from Salta City, Argentina. The loss and transformation of habitat by anthropogenic activities is one of the main causes of biodiversity decrease. Amphibians are declining all over the world and one of the causes of this decline is thought to be habitat reduction. However, there are anuran populations in highly disturbed habitats, like cities. This study presents the ecological baseline needed to understand anuran communities in urban environments, for Salta City, Argentina (ca. 502 000 inhabitants. The sample was stratified by environments defined by infrastructure and geographic location. The species were identified by visual encounter techniques and by auditory transect during the 2002-2003 reproductive period. Three families, seven genera and twelve species were recorded and the species richness decreased from city border to center. Similarity index values among geographic areas was higher East-West (94.7 than South-West (33.3. Bufo arenarum was the only species recorded in all environments. Hyla andina and Odontophrynus americanus had a restricted distribution and are here considered vulnerable. The border effect can explain some distribution pattern in these populations. A map of the potential distribution of recorded species for Salta is provided. Rev. Biol. Trop. 53(3- 4: 569-575. Epub 2005 Oct 3.

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

    Energy Technology Data Exchange (ETDEWEB)

    Stark, K. [Stockholm University (Sweden)

    2014-07-01

    Although amphibians are threatened world-wide, many amphibian species are protected in national legislation. Thus, amphibians need special attention in many environmental risk assessments for releases of contaminants such as radionuclides. In fact, amphibians' ecology and physiology (including, for example, a complex life-cycle with both aquatic and terrestrial life stages, and a thin skin) makes them sensitive to radiation exposure. In current dose models for wildlife, homogenous distribution of radionuclides in soil is assumed. However, soils are heterogeneous environments and radionuclide contamination can be very unevenly distributed. As a consequence, bioaccumulation of radionuclides in biota may vary on a local scale. Specifically, organisms' spatial location and movement within habitats may affect both their external and internal exposure pattern to radionuclides. Therefore, measuring the spatial location of individual amphibians within ecosystems and understanding why they use these different locations is essential for predicting potential effects of released radionuclides on these populations. The aim of this study was to investigate amphibians' spatial distribution in a {sup 137}Cs contaminated wetland area and their body content of {sup 137}Cs at the beginning and end of the summer period. The study site was a wetland nature reserve called Bladmyra near Gaevle in the central-eastern part of Sweden. This area received fallout of {sup 137}Cs after the Chernobyl accident in 1986. This study measured the spatial distributions of two amphibian species (Rana arvalis and Bufo bufo) with Passive Integrated Transponder (PIT) tags in a mark-and-recapture study during 2012-2014. In addition, {sup 137}Cs body content in the two species was measured by whole body counting in spring and autumn of 2013. The results showed differences between years in how marked animals used the study area: More individuals stayed in a small area during 2012 than in 2013, possibly due to differences in summer precipitation and food availability. Measured activity concentrations of {sup 137}Cs in the two amphibian species were still relatively high even 27 years after the Chernobyl fallout. Whole body activity concentrations showed higher levels during spring than autumn. Importantly, even animals captured in the same area showed large variability in whole body activity concentrations, suggesting that individual foraging areas are important for uptake. The present data were compared with data for R. arvalis from 2001 from a nearby wetland site with ten times higher activity concentrations of {sup 137}Cs. This comparison suggested that concentration ratios (CRs) may differ up to two orders of magnitude between nearby sites (< 5 km). Notably, less {sup 137}Cs was taken up by R. arvalis in the higher contamination level areas. To conclude, a comprehensive environmental risk assessment for radionuclides needs to take into account the amphibians' ecology (spatial location, movement, and forage area). One aspect is to consider the timing of sampling for whole body measurements of amphibians and to use ranges (min-max) of concentration ratio (CR) values in internal dose calculations. Another aspect is to collect data over several years because differences in weather conditions between years affect water levels in wetland areas and food availability. Document available in abstract form only. (authors)

  11. Bioacustical and etho-ecological features in amphibian communities of Southern Cordoba province (Argentina

    Directory of Open Access Journals (Sweden)

    Salas, Nancy E.

    1998-01-01

    Full Text Available El conocimiento de las características del canto de los anfibios constituye un importante elemento para la identificación de las especies que puede ser empleado como herramienta para prácticas estandarizadas de monitoreo. En el presente trabajo se resaltan las diferencias eto-ecológicas más notables (hábitat de reproducción, sitio de canto, actividad estacional y diaria de aquellas especies que integran las comunidades del sur de la Provincia Córdoba y se proporciona una clasificación de los cantos nupciales. La batracofauna del área de llanura del sur-este de la provincia de Córdoba está representada por 9 especies de leptodactílidos correspondientes a 5 géneros (Leptodactylus gracilis, L. mystacinus, L. latinasus latinasus, L. ocellatus, Pleurodema tucumanum, Physalaemus biligonigerus, Odontophrynus americanus, Ceratophrys cranwelli y C. ornata, 2 especies de bufónidos (Bufo arenarum y B. fernandezae y un hílido (Hyla pulchella pulchella. Los registros acústicos obtenidos en el campo durante el período reproductivo fueron analizados a través de programas de análisis digital de sonido, comparándose los siguientes parámetros: frecuencia dominante, duración del canto, intervalo entre cantos; se realizaron además descripciones respecto del tipo de canto y su modulación. Se reconocieron tres tipos de cantos básicos segun su duración, categoría que fue subdividida por la forma de la imagen oscilográfica. El resultado de este análisis establece que existen notables diferencias entre los cantos nupciales, principalmente a nivel de rangos de frecuencia dominante y duración de las emisiones. Esta partición del espacio sonoro representa un mecanismo de aislamiento reproductivo que minimiza la interacción entre especies simpátricas cuya reproducción muestra también un solapamiento temporal. Knowledge of the characteristics of amphibian calls is essential for species identification, and may be used as a tool in standardized monitoring practices. In the present work, the most important etho-ecological differences (reproduction habitat, call site, daily and seasonal activity of species that constitute the communities of southern Cordoba Province are indicated, and a classification of advertisement calls is provided. The anuran fauna of the plain area of the southern-central Córdoba Province is represented by 9 species of leptodactylids belonging to 5 genera (Leptodactylus gracilis, L. mystacinus, L. latinasus latinasus, L. ocellatus, Pleurodema tucumanum, Physalaemus biligonigerus, Odontophlynus americanus, Ceratophrys cranwelli and C. ornata, 2 species of bufonids (Bufo arenarum and B. fernandezae and one hylid (Hyla pulchella pulchella. The acoustic records obtained in the field during the reproductive period were analyzed through a program of sound digital analysis comparing the following parameters: dominant frequency, call duration and interval between calls; descriptions regarding type of call and modulation were also made. Three types of basic calls were recognized based on duration; this category was sub-divided depending on the shape of the oscillographic image. Results of this analysis revea] marked differences between advertisement calls, mainly at the level of dominant frequency ranges and call duration. This partition of sound space represents a mechanism of mating isolation that minimizes the interaction between sympatric species that breed at the same time.

  12. Consideracões sobre a natureza, desenvolvimento e transmissão de Cytamoeba bacterifera Labbé, 1894 de Leptodactylus ocellatus Considerations about the nature, development and transmission of Cytamoeba bacterifera Labbé, 1894 from Leptodactylus ocellatus

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    Maria Auxiliadora de Sousa

    1975-01-01

    Full Text Available Com o objetivo de fornecer dados para o esclarecimento do controvertido problema da natureza de Cytamoeba bacterifera freqüentemente encontrada nos eritrócitos de Leptodactylus ocellatus, realizamos alguns testes citoquímicos. Demonstramos a presença do ácido ribonucleico e polissacarídeos não digeríveis pela ptialina em sua estrutura. Com o método de Feulgen, teste de referência para a caracterização do ácido desoxirribonucleico, obtivemos principlemnte resultados negativos; porém, um parasito com fraca e difusa positividade e algumas reações duvidosas também foram encontrados. Ao emrpegarmos o Verde Metila-Pironina, mesmo após o tratamento pela ribonuclease, e o Azul de Toluidina, também depois da ação desta enzima, não conseguimos confimar a presença de ADN. Como os elementos constituintes de C. bacterifera são minúsculos e, às vezes, não evidenciáveis, é possível que seu teor de ADN, porventura existente, seja muito pequeno e, conseqüentemente, de difícil demonstração por métodos cujos resultados são observados sob microscopia ótica, além de poder ficar facilmente encoberto por outras substâncias. Não estamos propensos a admitir uma provável natureza virótica para Cytamoeba baseados, principalmente, em alguns de seus aspectos estruturais (figs. 8, 15, 17 e 18 e na ausência de alteração no núcleo das células parasitadas. Apesar de não termos comprovado a presença de ADN, achamos possível que C. bacterifera seja um aglomerado intracitoplasmático de organismos modificados, cujas dimensões situam-se nas proximidades do limite de resolução do microscópio ótico, relacionados com as bactérias, assim como são, por exemplo, os Clamídios e as Riquétsias. Observamos o desenvolvimento de Cytamoeba em rã mantida em cativeiro por três meses e semanalmente examinada; constatamos decréscimo paulatino da parasitemia inicial e também que os seus tipos estruturais e medidas não estavam relacionadas com a etapa da infecção. Não conseguimos transmitir, por inoculação intra-peritoneal, Cytamoeba de L. ocellatus para Bufo crucifer.In view to furnish data to elucita the controversial problem of the nature of Cytamoeba bacterifera, which it is often found in erythrocytes of the frog Leptodactylus ocellatus, we have done some cytochemical tests. We displayd in its structure the contents of RNA and polysaccharides that do not undergo digestion by ptyalin. With the Feulgen's method we mainly obtained negative results, but one parasite showed a faintly diffused positivity and a few doubtful reaction were also observed. When we employed the Methyl Green-Pyronin, even after the ribonuclease treatment, and the Toluidin Blue, likewise subsequent to the activity of this enzime, we did not evidence the DNA. Taking into account that the components of C. bacterifere are usually very small and sometimes undiscernible, it is probable that their contents of DNA, perhaps existent, would be difficultly demonstrated under the light microscope, and also that it would be easily dissimulated by other substances. We do not believe in a viral nature of Cytamoeba mainly regarding some aspects of its structure (figs. 8, 15, 17 and 18 and the absence of damage on the nucleous of the infected cells. Although we did not prove the presence of DNA, we think that it is possible that C. bacterifera is an intracytoplasmic clump of modified organisms wich sizes are just within the nearness of th limit of visibility with optical microscopes, related with the bacteria, such as are, by exemple, the Chlamydiae and Rickettsiae. The development of Cytamoeba was followed in a frog maintained int he laboratory during three months and weekly examined; we observed progressive decrease of the parasitismo. Its structural types and sizes were not related with the phasis of the infection. We did not get transmission by intraperitonela inoculation of C. bacterifera from L. ocellatus to Bufo crucifer.

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

    International Nuclear Information System (INIS)

    Although amphibians are threatened world-wide, many amphibian species are protected in national legislation. Thus, amphibians need special attention in many environmental risk assessments for releases of contaminants such as radionuclides. In fact, amphibians' ecology and physiology (including, for example, a complex life-cycle with both aquatic and terrestrial life stages, and a thin skin) makes them sensitive to radiation exposure. In current dose models for wildlife, homogenous distribution of radionuclides in soil is assumed. However, soils are heterogeneous environments and radionuclide contamination can be very unevenly distributed. As a consequence, bioaccumulation of radionuclides in biota may vary on a local scale. Specifically, organisms' spatial location and movement within habitats may affect both their external and internal exposure pattern to radionuclides. Therefore, measuring the spatial location of individual amphibians within ecosystems and understanding why they use these different locations is essential for predicting potential effects of released radionuclides on these populations. The aim of this study was to investigate amphibians' spatial distribution in a 137Cs contaminated wetland area and their body content of 137Cs at the beginning and end of the summer period. The study site was a wetland nature reserve called Bladmyra near Gaevle in the central-eastern part of Sweden. This area received fallout of 137Cs after the Chernobyl accident in 1986. This study measured the spatial distributions of two amphibian species (Rana arvalis and Bufo bufo) with Passive Integrated Transponder (PIT) tags in a mark-and-recapture study during 2012-2014. In addition, 137Cs body content in the two species was measured by whole body counting in spring and autumn of 2013. The results showed differences between years in how marked animals used the study area: More individuals stayed in a small area during 2012 than in 2013, possibly due to differences in summer precipitation and food availability. Measured activity concentrations of 137Cs in the two amphibian species were still relatively high even 27 years after the Chernobyl fallout. Whole body activity concentrations showed higher levels during spring than autumn. Importantly, even animals captured in the same area showed large variability in whole body activity concentrations, suggesting that individual foraging areas are important for uptake. The present data were compared with data for R. arvalis from 2001 from a nearby wetland site with ten times higher activity concentrations of 137Cs. This comparison suggested that concentration ratios (CRs) may differ up to two orders of magnitude between nearby sites (137Cs was taken up by R. arvalis in the higher contamination level areas. To conclude, a comprehensive environmental risk assessment for radionuclides needs to take into account the amphibians' ecology (spatial location, movement, and forage area). One aspect is to consider the timing of sampling for whole body measurements of amphibians and to use ranges (min-max) of concentration ratio (CR) values in internal dose calculations. Another aspect is to collect data over several years because differences in weather conditions between years affect water levels in wetland areas and food availability. Document available in abstract form only. (authors)

  14. Hábitos alimentarios de Kinosternon Herrerai Stejneger 1925 (Testudines: Kinosternidae en el centro de Veracruz, México

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    Gustavo Aguirre Le\\u00F3n

    2004-01-01

    Full Text Available La alimentación de Kinosternon herrerai fue estudiada de octubre de 1999 a septiembre de 2000 en el extremosur de su distribución geográfica, en arroyos cercanos a la ciudad de Xalapa, Veracruz. Por medio de lavadoestomacal se obtuvieron contenidos estomacales (n= 48 de tortugas adultas capturadas de forma manual y entrampas con cebo. Los valores estacionales de frecuencia de ocurrencia, frecuencia numérica y volumen enporcentaje de 21 categorías de alimento encontradas en los estómagos mostraron que K. herrerai consumió enorden de importancia crustáceos decápodos (Procambarus sp., materia animal mixta, materia vegetal mixta,anuros adultos (Eleutherodactylus sp. Rana sp. y Bufo marinus, frutos de Ficus sp., larvas de odonatos y larvasde anuros. Estas tortugas son omnívoras, sin embargo tanto las hembras (92% vs. 52% como los machos (85.7%vs. 52.4% ingirieron categorías de alimento animal en mayor proporción que las categorías de alimento vegetal.Kinosternon herrerai presenta un patrón alimentario generalista a través de todas las estaciones del año, y unarespuesta oportunista en el consumo de algunas categorías de alimento, como los huevos de anuros. Los valoresde diversidad trófica de los dos sexos fueron variables entre estaciones del año (índice de diversidad de Herrera:2.77 a 16.65 en hembras y 3.3 a 15.24 en machos, sin embargo, las hembras muestran especialización temporalen la dieta durante el verano y los machos durante la primavera y el invierno, cuando la diversidad trófica fuemenor para cada sexo. La semejanza de la dieta entre hembras y machos (índice simplificado de Morisita fuemayor en el verano y el invierno (0.67 y 0.66 y disminuyó en la primavera y el otoño (0.60 y 0.55, lo que sugiereque estacionalmente hay cierto grado de reparto de recursos entre machos y hembras de esta especie.

  15. Chytrid fungus infections in laboratory and introduced Xenopus laevis populations: assessing the risks for U.K. native amphibians

    Science.gov (United States)

    Tinsley, Richard C.; Coxhead, Peter G.; Stott, Lucy C.; Tinsley, Matthew C.; Piccinni, Maya Z.; Guille, Matthew J.

    2015-01-01

    The chytrid fungus Batrachochytrium dendrobatidis (Bd) is notorious amongst current conservation biology challenges, responsible for mass mortality and extinction of amphibian species. World trade in amphibians is implicated in global dissemination. Exports of South African Xenopus laevis have led to establishment of this invasive species on four continents. Bd naturally infects this host in Africa and now occurs in several introduced populations. However, no previous studies have investigated transfer of infection into co-occurring native amphibian faunas. A survey of 27 U.K. institutions maintaining X. laevis for research showed that most laboratories have low-level infection, a risk for native species if animals are released into the wild. RT-PCR assays showed Bd in two introduced U.K. populations of X. laevis, in Wales and Lincolnshire. Laboratory and field studies demonstrated that infection levels increase with stress, especially low temperature. In the U.K., native amphibians may be exposed to intense transmission in spring when they enter ponds to spawn alongside X. laevis that have cold-elevated Bd infections. Exposure to cross-infection has probably been recurrent since the introduction of X. laevis, >20 years in Lincolnshire and 50 years in Wales. These sites provide an important test for assessing the impact of X. laevis on Bd spread. However, RT-PCR assays on 174 native amphibians (Bufo, Rana, Lissotriton and Triturus spp.), sympatric with the Bd-infected introduced populations, showed no foci of self-sustaining Bd transmission associated with X. laevis. The abundance of these native amphibians suggested no significant negative population-level effect after the decades of co-occurrence. PMID:25843959

  16. Is Phosphorylation of the ?1 Subunit at Ser-16 Involved in the Control of Na,K-ATPase Activity by Phorbol Ester–activated Protein Kinase C?

    Science.gov (United States)

    Féraille, Eric; Béguin, Pascal; Carranza, Maria-Luisa; Gonin, Sandrine; Rousselot, Martine; Martin, Pierre-Yves; Favre, Hervé; Geering, Käthi

    2000-01-01

    The ?1 subunit of Na,K-ATPase is phosphorylated at Ser-16 by phorbol ester-sensitive protein kinase(s) C (PKC). The role of Ser-16 phosphorylation was analyzed in COS-7 cells stably expressing wild-type or mutant (T15A/S16A and S16D-E) ouabain-resistant Bufo ?1 subunits. In cells incubated at 37°C, phorbol 12,13-dibutyrate (PDBu) inhibited the transport activity and decreased the cell surface expression of wild-type and mutant Na,K-pumps equally (?20–30%). This effect of PDBu was mimicked by arachidonic acid and was dependent on PKC, phospholipase A2, and cytochrome P450-dependent monooxygenase. In contrast, incubation of cells at 18°C suppressed the down-regulation of Na,K-pumps and revealed a phosphorylation-dependent stimulation of the transport activity of Na,K-ATPase. Na,K-ATPase from cells expressing ?1-mutants mimicking Ser-16 phosphorylation (S16D or S16E) exhibited an increase in the apparent Na affinity. This finding was confirmed by the PDBu-induced increase in Na sensitivity of the activity of Na,K-ATPase measured in permeabilized nontransfected COS-7 cells. These results illustrate the complexity of the regulation of Na,K-ATPase ?1 isozymes by phorbol ester-sensitive PKCs and reveal 1) a phosphorylation-independent decrease in cell surface expression and 2) a phosphorylation-dependent stimulation of the transport activity attributable to an increase in the apparent Na affinity. PMID:10637289

  17. Differential metamorphosis alters the endocrine response in anuran larvae exposed to T3 and atrazine

    International Nuclear Information System (INIS)

    Pesticide chemical contamination is one of the suspected contributors of the amphibian population decline. The herbicide atrazine is one of the major surface water contaminants in the U.S. A previous study has shown that atrazine at concentrations as low as 100 parts per billion (ppb) increased the time to metamorphosis in Xenopus laevis tadpoles. However, questions remain as to the applicability of a study of a non-native species to a native organism. The possible effects of atrazine on developing Bufo americanus were explored. Atrazine at potentially (albeit high) environmental concentrations was found not to delay the metamorphosis of developing B. americanus tadpoles as observed in X. laevis. Several studies have indicated that atrazine affects thyroid hormones. Since thyroid hormones are critical in amphibian metamorphosis, B. americanus and X. laevis tadpoles were exposed to exogenous 3,5,3'-triiodothyronine (T3). X. laevis were found to be more responsive to the effects of exogenous T3 compared to B. americanus, indicating that X. laevis may be more sensitive to endocrine active chemicals than B. americanus. In X. laevis, nuclear heterogeneity has been associated with metamorphosis. Flow cytometric analysis of the nuclei of normal metamorphing B. americanus indicates a decrease in the amount of thyroid mediated chromatin alterations relative to the nuclei of metamorphing X. laevis. Indications are that the differential response to endocrinthat the differential response to endocrine disruption is due to the differential role of chromatin associated gene expression during metamorphosis of B. americanus versus X. laevis. A second native species, Hyla versicolor, was observed to have the X. laevis nuclear pattern with respect to metamorphosis. As such, sensitivity to endocrine disruption is hypothesized not to be limited to laboratory non-native species

  18. Relevance of multiple spatial scales in habitat models: A case study with amphibians and grasshoppers

    Science.gov (United States)

    Altmoos, Michael; Henle, Klaus

    2010-11-01

    Habitat models for animal species are important tools in conservation planning. We assessed the need to consider several scales in a case study for three amphibian and two grasshopper species in the post-mining landscapes near Leipzig (Germany). The two species groups were selected because habitat analyses for grasshoppers are usually conducted on one scale only whereas amphibians are thought to depend on more than one spatial scale. First, we analysed how the preference to single habitat variables changed across nested scales. Most environmental variables were only significant for a habitat model on one or two scales, with the smallest scale being particularly important. On larger scales, other variables became significant, which cannot be recognized on lower scales. Similar preferences across scales occurred in only 13 out of 79 cases and in 3 out of 79 cases the preference and avoidance for the same variable were even reversed among scales. Second, we developed habitat models by using a logistic regression on every scale and for all combinations of scales and analysed how the quality of habitat models changed with the scales considered. To achieve a sufficient accuracy of the habitat models with a minimum number of variables, at least two scales were required for all species except for Bufo viridis, for which a single scale, the microscale, was sufficient. Only for the European tree frog ( Hyla arborea), at least three scales were required. The results indicate that the quality of habitat models increases with the number of surveyed variables and with the number of scales, but costs increase too. Searching for simplifications in multi-scaled habitat models, we suggest that 2 or 3 scales should be a suitable trade-off, when attempting to define a suitable microscale.

  19. The toxicity of Roundup Original Max to 13 species of larval amphibians.

    Science.gov (United States)

    Relyea, Rick A; Jones, Devin K

    2009-09-01

    With the increased use of glyphosate-based herbicides (marketed under several names, including Roundup and Vision), there has been a concomitant increased concern about the unintended impacts that particular formulations containing the popular surfactant polyethoxylated tallowamine (POEA) might have on amphibians. Published studies have examined a relatively small number of anuran species (primarily from Australia and eastern North America) and, surprisingly, no species of salamanders. Using a popular formulation of glyphosate (Roundup Original Max), the goal of the present study was to conduct tests of lethal concentrations estimated to kill 50% of a population after 96 h (LC50(96-h)) on a wider diversity of species from both eastern and western North America. Tests were conducted on nine species of stage 25, larval anurans from three families (Ranidae: Rana pipiens, R. clamitans, R. sylvatica, R. catesbeiana, R. cascadae; Bufonidae: Bufo americanus, B. boreas; and Hylidae: Hyla versicolor, Pseudacris crucifer) and four species of larval salamanders from two families (Ambystomatidae: Ambystoma gracile, A. maculatum, A. laterale; and Salamandridae: Notophthalmus viridescens). For the nine species of larval anurans, LC50(96-h) values ranged from 0.8- to 2.0-mg acid equivalents per liter with relatively little pattern in differential sensitivity among the species or families. The four species of larval salamanders were less sensitive than the anurans, with LC50(96-h) values ranging from 2.7- to 3.2-mg acid equivalents per liter and no substantial differences among the species of salamanders. This work substantially increases the available data on amphibian sensitivity to glyphosate formulations that include either POEA surfactants or the equally moderately to highly toxic surfactants of Roundup Original Max and should be useful for improving future risk assessments. PMID:19405783

  20. Roundup and amphibians: the importance of concentration, application time, and stratification.