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Sample records for natterjack toad bufo

  1. Genetic variability in geographic populations of the natterjack toad (Bufo calamita)

    Oromí Farrús, Neus; Richter-Boix, A; Sanuy i Castells, Delfí; Fibla Palazón, Joan

    2012-01-01

    Across altitudinal and latitudinal gradients, the proportion of suitable habitats varies, influencing the individual dispersal that ultimately can produce differentiation among populations. The natterjack toad (Bufo calamita) is distributed across a wide geographic range that qualifies the species as interesting for a geographic analysis of its genetic variability. Five populations of B. calamita in the Sierra de Gredos (Spain) were studied in an altitudinal gradient ranging from 750 to 2270 ...

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

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

    Allentoft, Morten E.; Siegismund, Hans Redlef; Briggs, Lars; Andersen, Liselotte Wesley

    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...

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

    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.

  5. Conservation genetics of an island toad: Bufo bufo in Jersey

    Wilkinson, John W.; Beebee, Trevor J. C.; Griffiths, Richard A.

    2007-01-01

    On Jersey (British Channel Islands), common toads often reproduce in small, urban ponds. This atypical breeding strategy has implications for their persistence and they have declined on the island in recent times. We used polymorphic microsatellite markers to compare genetic diversity in Bufo bufo from five different ponds in Jersey with two populations from north-west France. Genetic diversity of Jersey toads was comparable with that of populations elsewhere in Europe. Numbers of breeding fe...

  6. Phenotypic selection in common toad (Bufo bufo

    Cvetkovi? Dragana

    2007-01-01

    Full Text Available One of the most important problems for evolutionary biologists is to investigate the patterns and strength of phenotypic selection acting on quantitative traits in natural populations. Measurement of selection is complicated by the presence of correlations between characters; selection on a particular trait produces not only a direct effect, but indirect effects as well. Despite the growing body of phenotypic selection studies in a variety of taxa, studies on amphibians are still sparse. The aim of this study was to estimate patterns and strength of selection acting on a set of correlated characters in a natural population of Bufo bufo from the vicinity of Belgrade, Serbia. Morphological traits (body length, fore- and hind leg length were measured, while fitness was assayed as fecundity and gonad weight for females and males, respec­tively. The regression approach was used to estimate selection differentials and gradients. Selection patterns differed between the sexes - linear selection differentials showed significant total directional selection for body size in females, but not in males. In males, differentials were significant for both fore- and hind leg lengths. Sample size did not permit identification of significant nonlinear (quadratic selection.

  7. Progressive Skinning of Toads (Bufo bufo by the Eurasian Otter (Lutra lutra

    Slater F.

    2002-04-01

    Full Text Available Predation of the Common Toad (Bufo bufo by otters is less common than predation of the Common Frog (Rana temporaria. To avoid the paratoid glands of toads, only the hind legs may be skinned and eaten. At a B. bufo breeding site, regularly predated by otters, an increasing proportion of predated toads have been completely skinned. With declining populations of fish and crustacean prey, it is suggested that this apparent behavioural change better utilises the residual food resource.

  8. Visual optics in toads (Bufo americanus).

    Mathis, U; Schaeffel, F; Howland, H C

    1988-06-01

    Aspects of visual optics were investigated in the American toad (Bufo americanus). The development of the refractive state of the eye during metamorphosis was followed with IR photoretinoscopy. Frozen sections documented the changes in optical parameters before and after metamorphosis. There is a difference in light sensitivity between juvenile and adult toads. Binocular accommodation in adult toads was observed. 1. IR photoretinoscopic measurements showed that the refractive state of the eye changed very rapidly during metamorphosis, about 10 D/h while the animal entered the terrestrial habitat. 2. Frozen sections showed that the almost spherical lens in a tadpole eye had flattened in a just metamorphosed toad's eye while at the same time the distance of the lens to the retina had decreased. However, the morphological measurements were not sufficiently sensitive to record the relatively small changes in ocular dimensions that were responsible for the rapid changes in refractive state during metamorphosis. 3. Schematic eyes, with homogeneous and non homogeneous lenses, were constructed for tadpoles, juvenile toads, and adult toads. 4. Nonparaxial raytracing studies in schematic eyes suggested that the lenses of animals of the three developmental stages tadpole, juvenile toad, and adult are not homogeneous but have a refractive index gradient. The raytracing studies indicated that the refractive index gradient is different for the different developmental stages, being highest in the tadpole lens. 5. The observations of toads during feeding behavior at different light levels showed an increased light sensitivity in the adult nocturnal toads in contrast to the juvenile animals, which are diurnal. The increased light sensitivity could partly be explained with an increase in aperture and an increase in red rod outer segments. To fully explain the higher light sensitivity in adult toads, changes in neuronal parameters had to be assumed. 6. Retinoscopic measurements of the resting refractive state in the adult toad showed a hyperopic defocus of about +8 D. By subtracting the measurement artefact for retinoscopy, the true resting focus was found to be nearly emmetropic. 7. The amount of natural accommodation in adult toads during normal feeding behavior was investigated with IR photoretinoscopy. Binocular accommodation of about 8 D was observed. PMID:3404484

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

    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.)

  10. Final Critical Habitat for the Houston toad (Bufo houstonensis)

    US Fish and Wildlife Service, Department of the Interior — To provide the user with a general idea of areas where final critical habitat for Houston toad (Bufo houstonensis) based on the description provided in the Federal...

  11. Sumithion Induced Hepatic Injury in the Toads Bufo tibamicus

    S. A. Sakr

    2000-01-01

    Full Text Available The present work studied the effect of the organophosphate insecticide, sumithion on the liver of toads Bufo tibamicus. Feeding toads with a daily dose of sumithion ( 40 mg / kg body weight for 10 days caused histological alterations in the liver . The normal structural organization of the hepatic acini was impaired , the hepatocytes showed cytoplasmic vacuolation and the blood vessels were congested . Moreover, elevations of transaminases ( GOT , GPT were recorded in the sera of treated animals . The obtained results collectively indicated that sumithion treatment induced liver injury in the toads .

  12. Determinants of Instrumental Extinction in Terrestrial Toads ("Bufo arenarum")

    Muzio, Ruben N.; Ruetti, Eliana; Papini, Mauricio R.

    2006-01-01

    Previous research in a water-reinforced instrumental training situation with toads ("Bufo arenarum") has shown that performance in both acquisition and extinction is poorer after partial, rather than continuous reinforcement training. In Experiment 1, the performance of a group receiving 24 trials on a 50% partial reinforcement schedule was poorer…

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

    Isioma Tongo; Lawrence Ezemonye; Uche Ochei

    2012-01-01

    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 oxida...

  14. Biological activities of skin and parotoid gland secretions of bufonid toads (Bufo bufo, Bufo verrucosissimus and Bufotes variabilis) from Turkey.

    Nalbantsoy, Ayse; Karış, Mert; Yalcin, Husniye Tansel; Göçmen, Bayram

    2016-05-01

    Toad glandular secretions and skin extractions contain numerous natural agents which may provide unique resources for novel drug development. Especially the skin-parotoid gland secretions of toads from genus Bufo contain as many as 86 different types of active compounds, each with the potential of becoming a potent drug. In the present study, crude skin-parotoid gland secretions from Bufo bufo, Bufo verrucosissimus and Bufotes variabilis from Turkey were screened against various cancer cells together with normal cells using MTT assay. Furthermore, the antimicrobial properties of skin secretions were tested on selected bacterial and fungal species for assessing the possible medical applications. Antimicrobial activity of skin secretions was studied by determining minimal inhibitory concentration (MIC) in broth dilution method. Hemolytic activity of each skin-secretion was also estimated for evaluating pharmaceutical potential. Both skin-parotoid gland secretions showed high cytotoxic effect on all cancerous and non-cancerous cell lines with IC50 values varying between cancer and antimicrobial agents without hemolytic activities. PMID:27133069

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

    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.

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

    Isioma Tongo

    2012-07-01

    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.

  17. Abundance and Breeding Migration of the Asian Toad (Bufo gargarizans

    Sung, Hacheol

    2007-11-01

    Full Text Available We monitored a breeding population of the Asian toad (Bufo gargarizans, in the Wonheunge pondat Sannamdong, Chungju, from 5 March to 11 April, 2006 and 14 February to 31 March, 2007 to investigate theirmovement patterns, breeding population sizes, and physical characteristics. Terrestrial migration to the pondstarted on 5 March in 2006 and 14 February in 2007. We captured a total of 266 immigrating individuals (213males, 53 females in 2006 and 307 (222 males, 85 females in 2007, and found 50 adults apparently killedby motor vehicles while migrating to the pond in 2007. Emigration from the pond to terrestrial sites started on15 March 2006 and 5 March 2007. We captured a total of 245 emigrating toads (181 males, 65 females in2006 and 99 (92 males, 7 females in 2007. An additional 10 emigrating adults were found dead on the road.During both the immigration and emigration periods, two peaks in capture frequency appeared for each sex ineach breeding season. The immigration peaks corresponded with higher temperatures, while the emigrationpeaks corresponded with high humidity. Migrating Asian toads showed sexual size dimorphism and a malebiasedsex ratio. Body weights and SVL (snout-vent length of immigrating and emigrating individuals werenegatively related with migration dates.

  18. Adriamycin-induced neoplastic lesions in the Egyptian toad Bufo regularis.

    el-Mofty, M M; Khudoley, V V; Sakr, S A; Osman, S I; Toulan, B A

    1991-01-01

    Injecting adult toads (Bufo regularis) subcutaneously in the dorsal lymph sac with adriamycin at a dose of 2 mg/kg body weight, once every 3 weeks for 20 weeks, induced hepatocellular carcinomas in 20 out of 100 animals. Metastases of the primary liver tumors appeared in the kidneys of 7 toads. PMID:1997943

  19. Induction of hepatocellular carcinomas in the Egyptian toad Bufo regularis by an antifungal drug (griseofulvin).

    el-Mofty, M M; Khudoley, V V; Essawy, A E; Abdel-Kerim, H M

    1993-01-01

    Neoplastic lesions (hepatocellular carcinomas) were induced in the liver in 18 of 100 experimental toads (Bufo regularis) force fed with the antifungal drug griseofulvin, at a dose level of 0.4 mg/50 g every day. Maximal time of exposure and observation was 12 weeks. The first tumors appeared in 2 male toads 4 weeks after the initiation of feeding. PMID:8497379

  20. An Extraordinary New Toad (Bufo ttom Costa Rica

    Jay M Savage

    2002-06-01

    Full Text Available A new species of toad, Bufo periglenes, is described from the Lower Montane Rainforest zone of the Cordillera de Tilarán on the divide between Puntarenas and AlajueIa provinces, Costa Rica. The new form exhibits a combination of extremely bright coloration and marked sexual dichromism. Males are solid orange, females greenish to black with scarlet spots. The species lacks a tympanum and columella and is voiceless. Tadpoles are described. Relationships and the role of sexual dichromism are discussedSe describe una nueva especie de sapo, Bufo periglenes, del bosque montano bajo pluvial de la Cordillera de Tilarán en la divisoria entre las provincias de Puntarenas y Alajuela, Costa Rica. La nueva especie presenta una evidente combinación de colores brillantes y marcado dicromatismo sexual. Los machos son de un color anaranjado intenso uniforme, las hembras verdusco a negro con manchas rojo escarlata. Esta especie carece de tímpano, columela y voz. Se describen los renacuajos. Se discute el parentesco y el papel del dicromatismo sexual

  1. Enhancement of hepatic tumors induced by N-nitrosodimethylamine in female toads Bufo regularis by oestrone.

    Sakr, S A; el-Mofty, M M; Mohamed, A M

    1989-01-01

    The effect of oestrone on hepatic tumours induced in the female toads Bufo regularis by N-nitrosodimethylamine (DMNA) was evaluated. Injecting the toads with DMNA induced hepatocellular carcinomas in 17% comparable with 23% in toads injected with DMNA plus oestrone. These results show that oestrone insignificantly enhanced the tumour formation. Oestrone alone induced hepatic tumours in only 4 cases and was considered as a weak initiator. PMID:2923526

  2. Induction of neoplasms in the Egyptian toad Bufo regularis by gibberellin A3.

    el-Mofty, M M; Sakr, S A

    1988-01-01

    Force feeding the Egyptian toads (Bufo regularis) with gibberellin A3 (10 ppm) twice a week for 5 months induced neoplasms in 8 out of 50 (16%) experimental animals. Primary tumours developed in the liver (hepatocellular carcinomas). Two secondary tumours in the kidneys and another 2 in the ovaries of toads developed due to metastases from the hepatocellular carcinomas. The results show that gibberellic acid (gibberellin A3) has a carcinogenic effect in the Egyptian toads. PMID:3340394

  3. The induction of neoplastic lesions by aflatoxin-B1 in the Egyptian toad (Bufo regularis).

    el-Mofty, M M; Sakr, S A

    1988-01-01

    The carcinogenic activity of aflatoxin-B1, the metabolic product of the mold Aspergillus flavus (a commonly occurring contaminant of groundnuts and other foodstuffs), was tested using the Egyptian toad (Bufo regularis). Injecting the toads with aflatoxin-B1 at a dose level of 0.01 mg/50 g body wt in 1 ml corn oil once a week for 15 weeks induced hepatocellular carcinomas in 19% of the experimental toads. Four toads developed tumors in the kidney due to metastases from the primary hepatocellular carcinomas. PMID:3127814

  4. Morphological differentiation of the common toad Bufo bufo (Linnaeus, 1758 in the central part of the Balkan Peninsula

    ?a?enovi? Natalija

    2013-01-01

    Full Text Available This study analyzes the degree of morphological differentiation among populations of the common toad Bufo bufo in the central part of the Balkan Peninsula. Variations in a number of morphometric and qualitative characters in 14 population samples were analyzed using univariate and multivariate statistics. We found a high degree of female-biased sexual size dimorphism. Morphological variation among the samples was more expressed in morphometric than in qualitative characters. The significant size differences that exist between northern and southern population groups could be the result of phenotypic plasticity. Our results do not support a clear split between northern and southern populations, contrary to the current taxonomic treatment of these groups as B. b. bufo and B. b. spinosus, respectively. [Projekat Ministarstva nauke Republike Srbije, br. 173043

  5. Induction of neoplasms in Egyptian toads Bufo regularis by oil of chenopodium.

    el-Mofty, M M; Khudoley, V V; Sakr, S A; Ganem, N F

    1992-01-01

    Feeding the Egyptian toad Bufo regularis with oil of the chenopodium plant induced hepatocellular carcinomas in 23% of the animals, and metastases of the primary liver tumors appeared in the kidneys of 6 toads. The earliest evidence of tumors appeared after 3 months of treatment. The average latent period of tumor induction was 3.6 +/- 0.4 months. It is speculated that oil of chenopodium may be one of the constituents of Chenopodium ambrosoides which is responsible for tumor induction in the toads B. regularis. PMID:1495755

  6. Hexamethonium produces both twitch and tetanic depression without fade in common African toad (Bufo regularis).

    Ajibola, E S; Adebayo, A O; Thomas, F C; Rahman, S A; Gbadebo, A M; Odunbaku, T A

    2009-12-01

    The study was designed to investigate the nature of the cholinoceptors at the sciatic nerve-gastrocnemius muscle junction of the common African toad (Bufo regularis). Using myographic technique, the twitch properties of the sciatic-gastrocnemius muscle preparation of the common African toad was studied. Both the twitch height and peak tetanic height were measured as a percentage of control. Hexamethonium at a concentration of 0.1 mM significantly [PBufo regularis) resemble the developing synapse of African clawed toad (Xenopus laevis) and may contain muscarinic M1 autoreceptors at the pre juntional membrane. PMID:20234748

  7. Immunolocation of mitochondria-rich cells in epidermis of the common toad, Bufo bufo L

    Spies, Ingrid B.M.

    Adult toads, skin, flask-shaped cells, cytoskeleton, keratin expression, immunohistochemistry, differentiation.......Adult toads, skin, flask-shaped cells, cytoskeleton, keratin expression, immunohistochemistry, differentiation....

  8. DIET OF THE SOUTHERN TOAD (BUFO TERRESTRIS) FROM THE SOUTHERN EVERGLADES

    We examined the diet of a February-May sample of the southern toad (Bufo terrestris) from the Everglades National Park. Above the familial level, 13 taxa were consumed, but ants (Hymenoptera) and beetles (Coleoptera) were consumed most by, and in the greatest number of sto...

  9. Developmental, histological and ultrastructural studies on the harderian gland of the Egyptian toad, Bufo regularis Reuss.

    Sabry, I; Rizk, T A

    1992-01-01

    The present study shows that the Harderian gland of the toad Bufo regularis starts to appear during development at stage 57 concomitant with the development of the nictitating membrane. In the adult toad, the gland was found to be formed of one lobe and occupying the antero-ventral aspect of the orbital cavity. No anatomical differences were noted between the male and female glands. The histological and ultrastructural studies showed that the Harderian gland is a compound tubular gland composed of rounded tubules lined by a single layer of epithelial cells and having a meshwork of myoepithelial cells surrounding the gland tubules. Differences were observed in the epithelial cells of female and male toads Bufo regularis. While females have a dilated rough endoplasmic reticulum and several secretory granules throughout the cytoplasm, males have a compact rough endoplasmic reticulum and numerous secretory granules and vacuoles. PMID:1490012

  10. Serum and hepatic vitamin A levels in captive and wild marine toads (Bufo marinus).

    Berkvens, Charlene N; Lentini, Andrew; Dutton, Christopher J; Pearl, David L; Barker, Ian K; Crawshaw, Graham J

    2014-01-01

    The captive breeding program for the endangered Puerto Rican crested toad (Peltophryne [Bufo] lemur) has been hampered by an undiagnosed condition called "Brown Skin Disease" (BSD). Toads develop widespread skin darkening, skin thickening and abnormal shedding and eventually succumb to a chronic loss of viability. This project evaluated the marine toad (Bufo marinus) as a model for the PRCT, examining vitamin A deficiency as a potential cause of BSD. Wild caught marine toads had significantly higher liver vitamin A concentrations (61.89 ± 63.49 µg/g) than captive born marine toads (0.58 ± 0.59 µg/g); P<0.001). A significant difference in serum vitamin A concentration was found between the captive and wild caught toads (P=0.013) and between the low vitamin A-fed and wild caught toads (P=0.004), when controlling for liver vitamin A concentrations. After captive toads were treated with topical and/or oral vitamin A, their hepatic vitamin A concentrations were similar to those of the wild toads, averaging 48.41 ± 37.03 µg/g. However, plasma vitamin A concentrations pre- and post-vitamin A supplementation did not differ statistically. We concluded that plasma vitamin A concentrations do not provide a linear indication of liver/body vitamin A status, and that both topical and oral supplementation with an oil-based vitamin A formulation can increase liver stores in amphibians. No evidence of BSD or other signs of deficiency were noted in the marine toads, although this feeding trial was relatively short (127 days). To date, clinical, pathological and research findings do not support vitamin A deficiency as a primary factor underlying BSD. PMID:25230391

  11. 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...

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

    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.

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

    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

  14. Aflatoxin-B1 inhibition of spermatogenesis in the toad Bufo regularis.

    Sakr, S A; el-Mofty, M M

    1990-01-01

    Aflatoxin-B1 was injected in a dose of 0.01 mg/50 g body weight into the dorsal lymph sac of male toads (Bufo regularis) to evaluate its effect on the testes. After three and six weeks' treatment the diameters of the seminiferous tubules were significantly reduced. Furthermore, spermatogenic cells were almost completely absent. The histological evidence also showed complete suppression of spermatogenesis. It is suggested that one or several AFB1 metabolites may be responsible for suppression of spermatogenesis in the given toads, through inhibition of testicular androgenic activity. PMID:1964670

  15. Adrenalin and hydroxytyramine in the parotid gland venom of the toad, Bufo marinus.

    GREGERMAN, R I

    1952-01-01

    Preparations from the parotid gland venom of the toad Bufo marinus have been analyzed by paper chromatography for the presence of adrenalin precursors. In addition to adrenalin itself, hydroxytyramine was identified and a second compound which appeared to be an adrenalin ester-perhaps lactyl-adrenalin. Two other compounds which appeared on the chromatogram could not be identified. Neither noradrenalin nor another possible precursor, epinine, appeared to be present. PMID:14898030

  16. The influence of ambient salinity and temperature on lipid metabolism in toad (Bufo bufo) skin. Is phosphatidylethanolamine an endogenous regulator of ion channels?

    Hansen, H.J.M.; Olsen, Allan Gylling; Willumsen, Niels J.

    1994-01-01

    transepithelial electrical potential in vitro. While all the incorporations in vitro showed (32P) and (14C) frog and toad skin phospholipid patterns dominated by phosphatidylcholine-independent of adaptational temperature and salinity--corresponding phospholipid patterns dominated by phosphatidylethanolamine (PE......Incorporation of (32P) phosphate and (14C) acetate into frog (Rana temporaria) skin phospholipids in vitro was positively correlated to skin MR cell density. Transport across toad (Bufo bufo) skin and incorporation into skin phospholipids of the radioactive tracers were independent of...

  17. Advertisemente calls of cuban toads of the genus Bufo (Anura, Bufonidae

    Roberto Alonso

    2003-12-01

    Full Text Available The Bufo peltocephalus group is comprised of ten species of toads from the West Indies. Cuba hosts the highest diversity, with a total of seven endemic species. Adequated acoustic characterization of the vocalizations remained absent for the majority of these species. We offer some natural history data on their calling behavior, calling/breeding sites and describe the spectral and temporal characteristics of the advertisement call for all seven Cuban toads, five of wich have no been described. The calls of each species differ from the rest in at least two of the examined parameters, particulary in dominant frequency and pulse rate. We observed two basic patterns of amplitude modulation. The first one, emitted from the three largest toad species, is characterized by long calls with trains of complex pulses. The second pattern, typical of the small and the intermediate size species, includes short calls with trains of simple pulses.

  18. The ecological impact of invasive cane toads (Bufo marinus) in Australia.

    Shine, Richard

    2010-09-01

    Although invasive species are viewed as major threats to ecosystems worldwide, few such species have been studied in enough detail to identify the pathways, magnitudes, and timescales of their impact on native fauna. One of the most intensively studied invasive taxa in this respect is the cane toad (Bufo marinus), which was introduced to Australia in 1935. A review of these studies suggests that a single pathway-lethal toxic ingestion of toads by frog-eating predators-is the major mechanism of impact, but that the magnitude of impact varies dramatically among predator taxa, as well as through space and time. Populations of large predators (e.g., varanid and scincid lizards, elapid snakes, freshwater crocodiles, and dasyurid marsupials) may be imperilled by toad invasion, but impacts vary spatially even within the same predator species. Some of the taxa severely impacted by toad invasion recover within a few decades, via aversion learning and longer-term adaptive changes. No native species have gone extinct as a result of toad invasion, and many native taxa widely imagined to be at risk are not affected, largely as a result of their physiological ability to tolerate toad toxins (e.g., as found in many birds and rodents), as well as the reluctance of many native anuran-eating predators to consume toads, either innately or as a learned response. Indirect effects of cane toads as mediated through trophic webs are likely as important as direct effects, but they are more difficult to study. Overall, some Australian native species (mostly large predators) have declined due to cane toads; others, especially species formerly consumed by those predators, have benefited. For yet others, effects have been minor or have been mediated indirectly rather than through direct interactions with the invasive toads. Factors that increase a predator's vulnerability to toad invasion include habitat overlap with toads, anurophagy, large body size, inability to develop rapid behavioral aversion to toads as prey items, and physiological vulnerability to bufotoxins as a result of a lack of coevolutionary history of exposure to other bufonid taxa. PMID:20919631

  19. Measuring energetics and behaviour using accelerometry in cane toads Bufo marinus.

    Halsey, Lewis G; White, Craig R

    2010-01-01

    Cane toads Bufo marinus were introduced to Australia as a control agent but now have a rapidly progressing invasion front and damage new habitats they enter. Predictive models that can give expansion rates as functions of energy supply and feeding ground distribution could help to maximise control efficiency but to date no study has measured rates of field energy expenditure in an amphibian. In the present study we used the accelerometry technique to generate behavioural time budgets and, through the derivation of ODBA (overall dynamic body acceleration), to obtain estimates of energetics in free ranging cane toads. This represents the first time that accelerometers have been used to not only quantify the behaviour of animals but also assign to those behaviours rates of energy expenditure. Firstly, laboratory calibrations between ODBA and metabolic rate were obtained and used to generate a common prediction equation for the subject toads (R(2) = 0.74). Furthermore, acceleration data recorded during different behaviours was studied to ascertain threshold values for objectively defining behaviour categories. Importantly, while subsequent accelerometer field deployments were relatively short they agreed with previous studies on the proportion of time that cane toads locomote yet suggest that the metabolic rate of cane toads in the wild may sometimes be considerably higher than might be assumed based on data for other species. PMID:20422048

  20. Variation in Chemical Defense Among Natural Populations of Common Toad, Bufo bufo, Tadpoles: the Role of Environmental Factors.

    Bókony, Veronika; Móricz, Ágnes M; Tóth, Zsófia; Gál, Zoltán; Kurali, Anikó; Mikó, Zsanett; Pásztor, Katalin; Szederkényi, Márk; Tóth, Zoltán; Ujszegi, János; Üveges, Bálint; Krüzselyi, Dániel; Capon, Robert J; Hoi, Herbert; Hettyey, Attila

    2016-04-01

    Defensive toxins are widespread in nature, yet we know little about how various environmental factors shape the evolution of chemical defense, especially in vertebrates. In this study we investigated the natural variation in the amount and composition of bufadienolide toxins, and the relative importance of ecological factors in predicting that variation, in larvae of the common toad, Bufo bufo, an amphibian that produces toxins de novo. We found that tadpoles' toxin content varied markedly among populations, and the number of compounds per tadpole also differed between two geographical regions. The most consistent predictor of toxicity was the strength of competition, indicating that tadpoles produced more compounds and larger amounts of toxins when coexisting with more competitors. Additionally, tadpoles tended to contain larger concentrations of bufadienolides in ponds that were less prone to desiccation, suggesting that the costs of toxin production can only be afforded by tadpoles that do not need to drastically speed up their development. Interestingly, this trade-off was not alleviated by higher food abundance, as periphyton biomass had negligible effect on chemical defense. Even more surprisingly, we found no evidence that higher predation risk enhances chemical defenses, suggesting that low predictability of predation risk and high mortality cost of low toxicity might select for constitutive expression of chemical defense irrespective of the actual level of predation risk. Our findings highlight that the variation in chemical defense may be influenced by environmental heterogeneity in both the need for, and constraints on, toxicity as predicted by optimal defense theory. PMID:27059330

  1. Histopathological Alterations in the Liver and Kidney of Toads (Bufo regularis) Intoxicated with a Pyrethroid Insecticide

    S. A. Sakr; S.M. Hanafy

    2002-01-01

    The effect of the pyrethroid insecticide, fenvalerate, on the liver and kidney of toad (Bufo regularis) was studied. Feeding toads with a daily dose of fenvalerate (0.5 mg/kg body weight) for three weeks caused histopathological alterations in these organs. The normal structural organization of the hepatic acini was impaired, the hepatocytes showed cytoplasmic vacuolation, the blood vessels were congested and there was remarkable abundance of leucocytic infiltrations. In the kidney, the renal...

  2. Histopathological Alterations in the Liver and Kidney of Toads (Bufo regularis Intoxicated with a Pyrethroid Insecticide

    S. A. Sakr

    2002-01-01

    Full Text Available The effect of the pyrethroid insecticide, fenvalerate, on the liver and kidney of toad (Bufo regularis was studied. Feeding toads with a daily dose of fenvalerate (0.5 mg/kg body weight for three weeks caused histopathological alterations in these organs. The normal structural organization of the hepatic acini was impaired, the hepatocytes showed cytoplasmic vacuolation, the blood vessels were congested and there was remarkable abundance of leucocytic infiltrations. In the kidney, the renal tubules were degenerated and the glomeruli were atrophied. Moreover, the transaminases enzymes GOT (glutamate-oxaloacetate transaminase and GPT (glutamate-pyruvate transaminase were elevated in the sera of treated animals. The magnitude of the changes was time-dependent being more prominent after the third week of treatment with fenvalerate.

  3. Preventive action of garlic on aflatoxin B1-induced carcinogenesis in the toad Bufo regularis.

    el-Mofty, M M; Sakr, S A; Essawy, A; Abdel Gawad, H S

    1994-01-01

    The action of fresh minced garlic and garlic oil on aflatoxin B1- (AFB1) induced carcinogenesis in the toad Bufo regularis was studied. Feeding toads with AFB1 induced tumors in 19% of the animals. Animals given AFB1 together with fresh garlic or garlic oil showed a significant reduction in tumor incidence. The tumor incidences were 3% and 9% in animals given AFB1 plus garlic and AFB1 plus garlic oil, respectively. In all three groups, the tumors were located in the liver (hepatocellular carcinomas), in addition to the kidney in animals treated with AFB1 alone and together with garlic. The kidney tumors were diagnosed as metastatic deposits from the primary liver tumors. It is speculated that one or more constituents of garlic may be responsible for inhibition of AFB1-induced carcinogenesis in B. regularis. PMID:8183725

  4. The carcinogenicity of some antimalarial drugs using the Egyptian toad Bufo regularis as a biological test animal.

    el-Mofty, M M; Khudoley, V V; Sakr, S A; Abdel-Gawad, H S

    1992-01-01

    Feeding Egyptian toads (Bufo regularis) with chloroquine and primaquine separately induced tumor formation in 14% and 19% of the animals, respectively. When chloroquine and primaquine were given in combination, the tumor incidence increased to 23.5%. Chloroquine feeding resulted in tumors located in the liver (lymphosarcomas) and primaquine in tumors in the kidney (histiocytic sarcomas). Toads fed chloroquine plus primaquine developed tumors in the liver, kidney, lung, and urinary bladder, and all the tumors were diagnosed as histiocytic sarcomas. It is speculated that one or more metabolites of chloroquine and primaquine (e.g., quinone) may be responsible for tumor induction in the toads. PMID:1437656

  5. Alpha-ecdysone, a new bracken fern factor responsible for neoplasm induction in the Egyptian toad (Bufo regularis).

    El-Mofty, M; Sadek, I; Soliman, A; Mohamed, A; Sakre, S

    1987-01-01

    Neoplastic lesions were induced in 10 out of 58 experimental toads (Bufo regularis) force-fed with alpha-ecdysone, which naturally occurs in the leaves of bracken fern (Pteris aquilina). The results of this study prove that alpha-ecdysone may be one of the factors responsible for the carcinogenicity of bracken fern plant fed to cattle and other experimental animals. PMID:3562288

  6. Ion transport mechanisms in the mesonephric collecting duct system of the toad Bufo bufo: microelectrode recordings from isolated and perfused tubules

    Møbjerg, Nadja; Larsen, Erik Hviid; Novak, Ivana

    2004-01-01

    It is not clear how and whether terrestrial amphibians handle NaCl transport in the distal nephron. Therefore, we studied ion transport in isolated perfused collecting tubules and ducts from toad, Bufo bufo, by means of microelectrodes. No qualitative difference in basolateral cell membrane...... amiloride application showed a small apical Na+ conductance. Arginine vasotocin depolarized Vbl. The small apical Na+ conductance indicates that the collecting duct system contributes little to NaCl reabsorption when compared to aquatic amphibians. In contrast, Vbl rapidly depolarized upon lowering of [Na......+] in the bath, demonstrating the presence of a Na+-coupled anion transporter. [HCO3-] steps revealed that this transporter is not a Na+-HCO3- cotransporter. Together, our results indicate that a major task of the collecting duct system in B. bufo is not conductive NaCl transport but rather K+ secretion...

  7. Properties of a conductive cellular chloride pathway in the skin of the toad (Bufo bufo)

    Larsen, Erik Hviid; Kristensen, P

    1978-01-01

    Two types of chloride current response to a step-wise hyperpolarization of the toad skin is demonstrated: (1) An "instantaneous" response observed immediately upon voltage change, and (2) a subsequent slow response, the time course of which is sigmoidal. The slow response is due to an increase of a...... transcellular conductance which is specific to chloride ions. The time constant of the conductance increase is dependent on the amplitude of the transepithelial voltage displacement, the smallest time constants are obtained for the highest amplitudes and are in the order of 30 s. The voltage dependences of the......-state phenomenon: In skins hyperpolarized for a few minutes, the "instantaneous" I-V curves show that the chloride pathway in the conducting state allows a large inward chloride current (outward chloride flux) to pass in the voltage range 40 mV greater than V greater than 0 mV. Calculations based on a three...

  8. Progesterone improves the number and quality of hormone induced Fowler toad (Bufo fowleri oocytes

    Li Hong

    2006-02-01

    Full Text Available Abstract Combinations of progesterone, lutenizing hormone releasing hormone analogue (LHRHa, human chorionic gonadotrophin (hCG, and the dopamine-2 (DA2 receptor antagonist 1-[1-[4,4-bis(4-Fluorophenylbutyl]-4-piperidinyl]-1,3-dihydro-2H-benzimidazol-2-one (Pimozide; Orap were tested for improvement of spawning rates, oocyte numbers, fertilization and neurulation rates of the Fowler toad (Bufo fowleri. Only treatments combined with progesterone produced large numbers of oocytes. The best treatment on oocyte numbers, neurulation rates, and the number of neurulas was with 5 mg progesterone, 20 mic.g LHRHa, and 0.25 mg Pimozide. Progesterone (5 mg with 60 mic.g LHRHa gave high spawning rates, oocyte numbers, and fertilization rates but neurulation rates were low. Progesterone alone in high repeated doses did not result in ovulation. High doses of LHRHa (60 mic.g with hCG, progesterone, and Pimozide gave the greatest number of toads spawning, however, they resulted in low oocyte numbers, fertilization and neurulation rates. A low dose of LHRHa (4 mic.g with hCG, or hCG alone as a second administration, and progesterone with Pimozide produced few good quality oocytes. Toads were given normal ovulatory doses of hormones 24 or 48 hrs after their initial dose, but these resulted in low oocyte numbers followed by poor fertilization. Overall, these results suggest that progesterone with a dose between 20 mic.g and 60 mic.g of LHRHa may be optimal for the induction of ovulation in these toads. Moreover, Pimozide can supplement low doses of LHRHa but not replace it.

  9. Carcinogenicity of flour infested with Tribolium castaneum using the Egyptian toad Bufo regularis as a biological test animal.

    el-Mofty, M M; Osman, S I; Sakr, S A; Toulan, B A

    1988-01-01

    Feeding the Egyptian toad Bufo regularis for 14 weeks with flour infested for 1 year with Tribolium castaneum, at a dose level of 200 mg/50 g body weight, induced neoplasms in 22 out of 100 toads. These neoplasms comprise 22 primary hepatocellular carcinomas and 6 tumours in the kidney due to metastases from the primary hepatocellular carcinoma. It is speculated that the carcinogenicity of the flour used in this work is due to quinone derivatives secreted by the defensive glands of T. castaneum. PMID:3340395

  10. The use of toads (Bufo regularis) in a new biological assay for screening chemicals or drugs which induce leukaemia in man.

    Elmofty, M; Abdelmeguid, N; Sadek, I; Essawy, A; Abdelaleem, E

    1997-01-01

    Injection of Egyptian toads Bufo regularis, with adriamycin subcutaneously in the dorsal lymph sac at a dose level of 0.1 mg/toad, once every 3 weeks for 3 months induced pronounced alterations in the blood cells. These alterations were more or less similar to the criteria reported in human leukaemia. These changes were all comparable to those observed after the treatment of the experimental animals with the chemical carcinogen 7,12-dimethylbenz(a)anthracene. It is speculated that toads (Bufo regularis) can be used as biological test animals for screening chemicals or drugs which induce leukaemia in man. PMID:21590119

  11. Spinal arthropathy associated with Ochrobactrum anthropi in free-ranging cane toads (Chaunus [Bufo] marinus) in Australia.

    Shilton, C M; Brown, G P; Benedict, S; Shine, R

    2008-01-01

    Inflammatory or degenerative pathology involving the vertebral bodies and/or ventral intervertebral joints has been described in numerous species, both captive and free ranging, including mammals, birds, and snakes, although never in amphibians. We described 15 cases of a newly recognized spinal arthropathy in adult cane toads (Chaunus [Bufo] marinus), an invasive species in Australia. Grossly appreciable lesions consisted primarily of ventral proliferation of bone and cartilage that resulted in ankylosis. Histologic examination of the entire vertebral columns of the 15 affected toads revealed 13 toads to have lesions at multiple intervertebral sites, totalling 41 intervertebral joints with lesions. Most lesions involved bone and cartilage proliferation that resulted in fusion of the joint, with (n = 15) or without (n = 9) associated pyogranulomatous inflammation. In the remaining 17 affected joints, histologic lesions were characterized by degeneration of articular cartilage without joint fusion. In addition, in one of these joints, there was also hemorrhage and pyogranulomatous inflammation. Bacterial culture of affected joints in 9 toads and grossly normal joints in 4 control toads resulted in isolation of Ochrobactrum anthropi in 7 affected toads but in none of the controls (P Invasive toads may be predisposed to this condition because of their large size; increased rates of movement; and, possibly, immunosuppression resulting from inhabiting a novel environment. PMID:18192584

  12. Influence of nitric oxide on histamine and carbachol-induced gastric Acid secretion in the common african toad - bufo regularis.

    Alada, A R A; Salahdeen, H M; Akande, O O; Idolor, G O

    2005-01-01

    The study aimed to determine the influence of nitric oxide (NO) on the action of histamine and carbachol on acid secretion in the common African toad - Bufo regularis. Gastric acidity was determined by titration method. The acid secretion was determined when nitric oxide was absent following administration of NO synthase inhibitor; N-nitro-L-arginine methyl ester (L-NAME) and when nitric oxide was in excess by administration of exogenous NO donor, sodium nitroprusside (SNP). Histamine or carbachol increased acid secretion in the toad. Acid output increased from 0.32 +/- 0.04 mEq/15min to 0.56 +/- 0.08 and 0.61 +/- 0.05 mEq/15min for histamine and carbachol respectively [P Bufo regularis. PMID:17220932

  13. Association preference and mechanism of kin recognition in tadpoles of the toad Bufo melanostictus

    Lilly Margaret Eluvathingal; Bhagyashri A Shanbhag; Srinivas K Saidapur

    2009-09-01

    In experiments with specially designed choice tanks, tadpoles of Bufo melanostictus spend significantly greater amounts of time near kin than near non-kin. However, in the absence of kin members, they prefer to spend more time near non-kin rather than stay away in isolation in the opposite blank zone with no company. This implies that association of toad tadpoles with their kin is due to attraction rather than repulsion from non-kin. Experiments designed to elucidate the sensory basis of kin recognition showed that toad tadpoles recognize their kin based on chemical cues rather than visual cues. They can also discriminate between homospecific non-kin and heterospecific (Sphaerotheca breviceps) tadpoles since the tadpoles spent significantly greater amounts of time near the former than near the latter. These findings suggest that where kin members are unavailable, selection may have favoured living with non-kin so as to derive benefits from group living and that a phenotype-matching mechanism may operate for both kin and species discrimination in B. melanostictus.

  14. Histological and Histochemical Studies on the Early Developmental Stages of the Egyptian Toad Bufo regularis Reuss

    Sayed, Alaa El-Din H.; Afaf I. Elballouz; Ekbal T. Wassif

    2015-01-01

    The present study was carried out to investigate the histological and histochemical changes in the liver and skin on different developmental stages of Egyptian toad Bufo regularis to be used as a histological key for such species. Our experiment started when tadpoles began to feed. The adapted embryos are divided into 3 large tanks of 200 embryos each, collections of samples started from feeding age every three days. Both histological and histochemical results showed that the general architec...

  15. Ultrastructure of the renal juxtaglomerular complex and peripolar cells in the axolotl (Ambystoma mexicanum) and toad (Bufo marinus).

    Hanner, R H; Ryan, G. B.

    1980-01-01

    Renal juxtaglomerular regions were examined in the axolotl (Ambystoma mexicanum and toad (Bufo marinus). Prominent granulated peripolar epithelial cells were found surrounding the origin of the glomerular tuft in the axolotl. These cells resembled the peripolar cells recently discovered in mammalian species. They contained multiple electron-dense cytoplasmic granules, some of which showed a paracrystalline substructure and signs of exocytoxic activity. Such cells were difficult to find and sm...

  16. The ontogeny of kin recognition in tadpoles of the toad Bufo melanostictus (Anura; Bufonidae)

    S K Saidapur; S Girish

    2000-09-01

    The ontogeny of kin recognition and influence of social environment on the development of kin recognition behaviour was experimentally investigated in tadpoles of Bufo melanostictus that lived in aggregations and showed low larval dispersion. Embryos and tadpoles of the toad were reared as (i) kin only, (ii) with kin and non-kin (separated by a mesh screen), and (iii) in isolation. They were tested for the ability to discriminate between (i) familiar siblings and unfamiliar non-siblings, (ii) familiar siblings and familiar non-siblings and, (iii) unfamiliar siblings and unfamiliar non-siblings. All tadpoles were fed on boiled spinach before conducting trials. Preference of test tadpoles to associate near the end compartments whether empty or containing members of specific stimulus groups was assessed using a rectangular choice tank. When tested in tanks with empty end compartments, the test tadpoles showed random distribution and thus no bias for the apparatus or the procedure. In the presence of kin/non-kin in the end compartments a significantly greater number of test tadpoles spent the majority of the time near familiar or unfamiliar kin rather than near familiar or unfamiliar non-kin. Kin discrimination ability persisted throughout larval development. Familiarity with siblings is not required for discriminating kin from non-kin, and kin discrimination ability is not modified following exposure to non-kin. Also, involvement of dietary cues is unlikely to be the prime mechanism of kin recognition in B. melanostictus unlike in some other anurans.

  17. Ultrastructural and molecular changes in the developing small intestine of the toad Bufo regularis.

    Sakr, S A; Badawy, G M; El-Borm, H T

    2014-01-01

    The ontogenetic development of the small intestine of the toad Bufo regularis was investigated using twofold approaches, namely, ultrastructural and molecular. The former has been done using transmission electron microscope and utilizing the developmental stages 42, 50, 55, 60, 63, and 66. The most prominent ultrastructural changes were recorded at stage 60 and were more evident at stage 63. These included the appearance of apoptotic bodies/nuclei within the larval epithelium, the presence of macrophages, swollen mitochondria, distorted rough endoplasmic reticulum, chromatin condensation, and irregular nuclear envelop, and the presence of large vacuoles and lysosomes. The molecular investigation involved examining DNA content and fragmentation. The results showed that the DNA content decreased significantly during the metamorphic stages 60 and 63 compared with both larval (50 and 55) and postmetamorphic (66) stages. The metamorphic stages (60 and 63) displayed extensive DNA laddering compared with stages 50, 55, and 66. The percentage of DNA damage was 0.00%, 12.91%, 57.26%, 45.48%, and 4.43% for the developmental stages 50, 55, 60, 63, and 66, respectively. In conclusion, the recorded remodeling of the small intestine represents a model for clarifying the mechanism whereby cell death and proliferation are controlled. PMID:24715821

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

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

    2010-01-01

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

  19. 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

    Shawna T. Park; 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...

  20. Hemoglobin affinity for oxygen in three subspecies of toads (Bufo sp. living at different altitudes

    HRVOJ OSTOJIC

    2000-01-01

    Full Text Available Blood oxygen affinity and red blood cell properties were measured in three subspecies of genus Bufo: Bufo spinulosus limensis, collected at sea level and at an average day temperature of 20ºC; Bufo spinulosus trifolium, from 3100 m, average day temperature of 15ºC; and Bufo spinulosus flavolineatus, from 4100 m, average day temperature of 10ºC. Electrophoresis of the hemoglobin showed the same component in each of the three subspecies. At 20ºC the blood oxygen affinities (P50 showed small differences between Bufo spinulosus limensis and Bufo spinulosus trifolium, whereas the value for Bufo spinulosus flavolineatus was markedly lower. At 10ºC, the ambient temperature of Bufo spinulosus flavolineatus, the P50 was extremely low compared with the other two subspecies at their corresponding ambient temperatures

  1. Effect of adriamycin on the morphology of the erythrocytes and blood parameters of the toad Bufo regularis.

    el-Mofty, M M; Sakr, S A; Osman, S I; Daabees, A Y; Toulan, B A

    1992-01-01

    The effect of the anticancer drug adriamycin on the morphology of the erythrocytes as well as some blood parameters were studied in the Egyptian toad Bufo regularis. Injecting the toads subcutaneously in the dorsal lymph sac with adriamycin at a dose level of 2 mg/kg body weight once every three weeks for 12 weeks induced the formation of abnormalities in the cytoplasm and nuclei of the erythrocytes. Its administration also caused severe anaemia, since the number of red blood corpuscles, haemoglobin content and haematocrit values were obviously decreased throughout the whole experimental period. The total leucocytic count was also diminished. On the other hand, the erythrocyte sedimentation rate was increased all over the experiment. PMID:1490008

  2. Histological and immunohistochemical studies of the endocrine cells of the gastrointestinal mucosa of the toad (Bufo regularis).

    El-Salhy, M; Grimelius, L; Wilander, E; Abu-Sinna, G; Lundqvist, G

    1981-01-01

    Using histological and immunhistochemical techniques, nine endocrine cell types were observed in the mucosa of the gastrointestinal tract of the toad, Bufo regularis, viz. enterochromaffin, somatostatin, glucagon, pancreatic polypeptide (PP), secretin, gastric inhibitory peptide (GIP), gastrin-C-terminal pentapeptide (GTPP), neurotensin and bombesin cells. The enterochromaffin cells were distributed throughout the gastrointestinal tract except the rectum. Somatostatin, glucagon, PP, secretin, GIP and GTPP cells were observed both in the stomach and in the small intestine. Neurotensin cells were seen only in the ileum and bombesin cells only in the pyloric and antral parts of the stomach. Immunostaining of consecutive sections did not reveal more than one polypeptide hormone in any of these cell types. It is concluded from the present results that the toad gastrointestinal mucosa contains endocrine cell types that are more or less homologous to those in the mammal alimentary tract, though some of them exhibit a different topographic distribution. PMID:6112216

  3. Carcinogenicity testing of black pepper (Piper nigrum) using the Egyptian toad (Bufo regularis) as a quick biological test animal.

    el-Mofty, M M; Soliman, A A; Abdel-Gawad, A F; Sakr, S A; Shwaireb, M H

    1988-01-01

    Milled black pepper (Piper nigrum) force-fed to Egyptian toads as a suspension in amphibian saline or injected subcutaneously in the dorsal lymph sac as an ethanol extract, induced primary tumours in the liver and secondary tumours in other organs (kidney and spleen). When applied to the skin of experimental animals as an ethanol extract, black pepper induced primary tumours in the liver and secondary tumours in the ileum and stomach. Tumours of the liver were diagnosed as hepatocellular carcinomas and those of the other organs as metastases of the primary liver tumours. It is speculated that one or more constituents of black pepper may be responsible for tumour induction in the organs of the Egyptian toad Bufo regularis. PMID:3368202

  4. A new neurohypophysial peptide, seritocin ([Ser5,Ile8]-oxytocin), identified in a dryness-resistant African toad, Bufo regularis.

    Chauvet, J; Michel, G; Ouedraogo, Y; Chou, J; Chait, B T; Acher, R

    1995-05-01

    From the pituitary neurointermediate lobe of the African toad Bufo regularis, vasotocin, hydrin 2 (vasotocinyl-Gly) and a mesotocin-like peptide have been isolated by HPLC and characterized by mass spectrometry, amino acid sequence and chromatographic coelution with synthetic peptides. The mesotocin-like peptide has been identified as [Ser5,Ile8]-oxytocin in place of mesotocin ([Ile8]-oxytocin) found in all other amphibians investigated to date. The name seritocin is suggested. The molecule is virtually devoid of oxytocic activity on rat uterus in contrast to mesotocin. On the other hand, the molar ratio of hydrin 2 to vasotocin in the pituitary reaches 2, whereas it is about 1 in toads and frogs from temperate regions. B. regularis is an anuran species able to withstand a hot and dry season by burrowing. The possible relationship between occurrence of seritocin and adaptation to arid environment remains to be demonstrated. PMID:7591488

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

    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.

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

    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.

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

    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 environmental exposure to coal combustion wastes interact to decrease survival in larval amphibians.

  8. Effect of light and dark on the developing retina of the Egyptian toad, Bufo regularis.

    Michael, M I; el-Mekkawy, D A; Rizk, T A

    1994-06-01

    The effect of light and dark on the retina of the Egyptian toad, Bufo regularis Reuss, was studied during its development from early larval stages till the end of metamorphosis. The observed changes in response to light and dark were restricted to the pigment epithelium and the photoreceptor cells. The animals examined were divided into four groups: 1-controls fixed in light (CL); 2-controls fixed in dark (CD); 3-animals maintained under continuous darkness (DD); and 4-animals exposed to continuous lighting (LL). In CD- and DD-animals, the location of melanin granules in the pigment epithelial processes (PEP) was restricted to the peripheral area between the apical portions of photoreceptor cells (scleral position). In CL-and LL-animals, on the contrary, abundant melanin granules were found in the PEP where they were dispersed more centripetally between the outer segments and ellipsoids of the visual cells (vitreal position). Photomechanical movements of the epithelial pigments were indicated in this species in response to light and dark before reaching the limb-bud stage. In DD-eye of the newly metamorphosed toadlets, the pigment epithelium appeared considerably thick and contained large lipid droplets when compared to that of the other three groups. Only in DD-animals some rod outer segments showed degeneration during the later stages of development. In addition, there was a remarkable reduction in the number of cones in the eyes of this group as a result of continuous light deprivation. Some differences in the position of cone nuclei were also observed in the retinae of the four groups. PMID:7976061

  9. Vasotocin and hydrin 2 (vasotocinyl-Gly) in the African toad Bufo regularis: study under various environmental conditions.

    Chauvet, J; Ouedraogo, Y; Michel, G; Acher, R

    1993-03-01

    1. The neurohypophysial osmoregulatory hormones of the African toad Bufo regularis, a species adapted to estivate under dry and hot conditions, have been investigated. Vasotocin and hydrin 2 (vasotocinyl-Gly) have been identified by their retention times in high-pressure reverse-phase liquid chromatography and coelution with synthetic peptides, their pharmacological properties (vasotocin) and microsequencing. 2. Vasotocin-associated neurophysin (MSEL-neurophysin type) has been characterized by its N-terminal amino acid sequence. 3. In toads subjected to dehydration by evaporation (20% weight loss) or to osmotic stress by immersion in 2% NaCl for 3 hr (6% weight loss), the molar ratio hydrin 2/vasotocin (about 2:1) remained similar to the one observed in control animals. 4. In toads exposed to saline solution, there was a large decrease (roughly 30%) in the amounts of both hormones in the neuro-hypophysis. Environmental conditions for distinct secretions of vasotocin and hydrin 2 remain to be found. PMID:8097151

  10. Determining the Effects of Cattle Grazing Treatments on Yosemite Toads (Anaxyrus [=Bufo] canorus) in Montane Meadows

    McIlroy, Susan K.; Lind, Amy J.; Allen-Diaz, Barbara H.; Roche, Leslie M.; Frost, William E.; Grasso, Rob L.; Kenneth W. Tate

    2013-01-01

    Amphibians are experiencing a precipitous global decline, and population stability on public lands with multiple uses is a key concern for managers. In the Sierra Nevada Mountains (California, USA), managers have specifically identified livestock grazing as an activity that may negatively affect Yosemite toads due to the potential overlap of grazing with toad habitat. Grazing exclusion from Yosemite toad breeding and rearing areas and/or entire meadows have been proposed as possible managemen...

  11. 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

    Park, Shawna T; Collingwood, Amanda M; St-Hilaire, Sophie; 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 inhibiting B. dendrobatidis in vitro, and therefore might be a factor in the toad’s coexistence with this pathogen. Isolates from 6 of 21 genera tested were found to inhibit the growth of B. dendrobatidis. These bacteria represent diverse lineages such as the Gammaproteobacteria, the Betaproteobacteria, and the Bacteroidetes/Chlorobium groups. We propose that these bacteria compete via microbial antagonism with B. dendrobatidis. PMID:24826077

  12. The natural heterohaemagglutinin in the serum of the toad Bufo regularis, and its relationship to lower vertebrate immunoglobulins.

    Balding, P; Gold, E R

    1976-05-01

    The serum of the toad Bufo regularis contains a natural heterohaemagglutinin for human erythrocytes, Which appears to have anti-(B + HP) specificity. Results of inhibition and absorption experiments indicate that only one agglutinin is present. The biochemical specificity of the agglutinin may be provisionally described as involving alpha-D-galactose residues linked (1-3) in the B determinant, of red cells possessing the H ANTIGEN. Unlike amphibian IgM, the agglutinin was insensitive to 2-mercaptoethanol treatment; moreover, it could be eluted from the alpha1 globulin region on cellulose acetate electrophoresis. These results suggest that this naturally occurring heterohaemagglutinin has a structure similar to that of plant and animal lectins. The relationship of this observation to the phylogenetic evolution of immunity is discussed. PMID:58835

  13. Effect of the dry-cold season dormancy on the tonic and phasic neural control of heart rate in the toad, Bufo paracnemis.

    Hoffmann, A; Romero, S M

    2000-06-15

    This work examined basal heart rate and autonomic cardiac tone as well as sympathetic cardiac reactivity to hypotension induced by systemic nitroprusside injection in dormant toads (dry-cold season), Bufo paracnemis, comparing the values with those of toads collected during the active months (hot-rainy season). Autonomic tone was calculated according to the method of Lin and Horwath ('72), which allows its evaluation as a percentage of intrinsic heart rate. Specimens were maintained in an outdoors terrarium except for the week preceding surgery, when they were transferred to indoor nonclimatized tanks. The heart rate of dormant toads (27.8 +/- 2.7 beats/min) was lower than that of active toads at rest (38.6 +/- 2. 3). Cholinergic tone was higher than adrenergic tone both in active (26.2% and 7.8%, respectively) and aestivated (19.5% and 4.8%, respectively) animals. Thus, cholinergic tone and adrenergic tone were both lower in dormant animals. The reflex tachycardia elicited by nitroprusside-induced hypotension was lower in aestivated toads (9.3 +/- 0.9 beats/min) when compared to active toads (19.9 +/- 1.0), indicating a reduced sympathetic reactivity. Nitroprusside-induced hypotensions were not different in the two groups. We conclude that at rest Bufo paracnemis heart is under the influence of a double cholinergic and adrenergic tone, and that both influences, as well as the reflex adrenergic reactivity to the unloading produced by nitroprusside-induced hypotension, are reduced in aestivated toads. PMID:10861545

  14. 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.

    Park, Shawna T; Collingwood, Amanda M; St-Hilaire, Sophie; 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 inhibiting B. dendrobatidis in vitro, and therefore might be a factor in the toad's coexistence with this pathogen. Isolates from 6 of 21 genera tested were found to inhibit the growth of B. dendrobatidis. These bacteria represent diverse lineages such as the Gammaproteobacteria, the Betaproteobacteria, and the Bacteroidetes/Chlorobium groups. We propose that these bacteria compete via microbial antagonism with B. dendrobatidis. PMID:24826077

  15. The effects of drought on population structure, activity, and orientation of toads Bufo quercicus and B. terrestris at a temporary pond

    Dodd, C.K., Jr.

    1994-01-01

    From 1985 through 1990, I monitored the populations of two species of toads, Bufo quercicus and B. terrestris, at a temporary pond in the xeric uplands of north-central Florida. A drift fence with pitfall traps completely encircled the pond basin; the fence was monitored 5 days per week throughout the year. The 5-year study coincided with a severe regional drought that resulted in generally short hydroperiods at unpredictable times of the year. More than 800 toads were captured. Successful metamorphosis never occurred at the pond although toads continued to visit it throughout the study. The sex ratio was male biased in B. quercicus but not in B. terrestris, although significant variation was observed from one year to the next. Likewise, the size-class structure and length-weight patterns varied among species, sexes, and years. Although fewer toads entered the pond basin as the study progressed, toads may have gone elsewhere to breed or they may have remained in refugia. Thus, decreased capture does not necessarily indicate that a drought-related population decline occurred. Drought may have disrupted normal arrival patterns and length of stay within the pond basin. Drought also could be responsible for variation in annual size-class structure of captured toads. The uncertainty of the hydroperiod both spatially and temporally in adjacent breeding sites, the ability of toads to move long distances with the potential for migration between breeding sites, and the lack of specificity in the choice of breeding sites (i.e. permanent versus different types of temporary wetlands) may lead to the formation of metapopulations in the xeric upland habitats of north-central Florida. Long-term monitoring under a variety of climatic conditions is needed to assess the effects of drought and other types of environmental stresses on toad populations.

  16. Biochemical studies on the blood and tissue components of the common Egyptian toad bufo regularis

    Al Nagdy, Sohair A. [سهير علي النجدي; Zahra, M. H.; Al-Zahaby, Al-Ahmady; El-Sabbagh, M. E.

    1995-01-01

    The effect of insulin and/or cortisone on the blood, serum and tissue levels of glucose, glycogen, pyruvic acid, lactic acid cholinesterase, alkaline phosphatase, aspartate amino transferase (AST), alanine amino-transferase (ALT) and total serum protein fractions was investigated in both males and females of Bufo regularis once in June and August. Metabolic activities in general were higher in August than in June. The intraperitoneal injection of insulin produced hypoglycemia but its effect o...

  17. Morphology of the large granular alveoli of the parotid glands in toad (Bufo ictericus) before and after compression.

    Toledo, R C; Jared, C; Brunner Juńior, A

    1992-07-01

    The parotid glands of toads are constituted by an accumulation of venom-producing granular alveoli. Parotid glands of Bufo ictericus were manually compressed and immediately excised. Normal glands (not submitted to compression) were also excised and processed for histological and ultrastructural observations. The glandular body of large granular alveoli in parotid glands is formed by a myoepithelial layer, internally covered by a syncytial secretory layer. In the normal parotid gland this layer is very electron dense, thus preventing clear visualization of organelles. Large secretion granules are located in the main secretion mass, near the syncytium. In the compressed parotid gland, the myoepithelium shows a number of alterations, including presence of myelin figures and foci of degradation in the cytoplasm. The organelles of the syncytial cytoplasm are easily observed. The mitochondria are swollen; the cristae are shortened or absent. Syncytial secretion granules and lengthened structures linked to the syncytial matrix are to be seen. A large amount of smooth endoplasmic reticulum is present, while the rough endoplasmic reticulum is reduced. This large quantity of smooth endoplasmic reticulum suggests enhanced synthesis of the cardiotoxic steroids of the venom. Alterations in the mitochondria and the presence of myelin figures and degenerative foci in the cytoplasm may probably be regarded as consequences of the cellular injury provoked by compression. PMID:1509492

  18. Actions of chloroquine and its N-oxidation metabolites on the rectus abdominis muscle of the toad (Bufo regularis).

    Ette, E I; Essien, E E; Marquis, V O; Ojewole, J A

    1981-09-01

    Using the isolate rectus abdominis muscle preparation of the toad (Bufo regularis) the pharmacological actions of chloroquine, chloroquine-N-oxide and chloroquine N-di-oxide were investigated. On their own at concentrations ranging from 7.5 x 10(-5) -5 x 10(-3)M, the compounds induced contractures, chloroquine being the most active. At lower concentrations (5 x 10(-7) - 5 x 10(-5) M), chloroquine and its N-oxides enhanced acetylcholine-induced contractures whereas they depressed the carbachol-evoked contractures. At higher concentrations (5 x 10(-4) - 5 x 10(-3)M), chloroquine and its N-oxides inhibited both ACh- and carbachol-induced contractures. Analysis of the results obtained showed that the antagonism between ACh (or carbachol) and chloroquine (or its N-oxides) is non-competitive. At low concentrations chloroquine and its N-oxides (5 x 10(-7) - 5 x 10(-5)M) inhibited the potentiating action of neostigimine on ACh-induced contractures. From the results obtained in the study presented here, it is suggested that the antagonism of acetylcholine (or carbachol) by chloroquine and its N-oxidation metabolites on this muscle preparation may be at the cellular level. It is also suggested that the compounds examined may be acting as anticholinesterases (with chloroquine being the most active). PMID:7325749

  19. The Glycoconjugate Changes of Apoptotic Skeletal Muscle Tissues in Regressing Eurasian Green Toad, Bufo viridis (Amphibia: Anura Tadpole Tail

    Mesut Sahin

    2006-01-01

    Full Text Available In the present study, programmed cell death of skeletal muscle tissues of the regressing tail of Euroasian green toad Bufo viridis (Amphibia: Anura tadpole was investigated with Hematoxylin-eosin (H+E and TUNEL methods in the three groups of different tail lengths. TUNEL stainings indicate that, during the tail regression, apoptotic skeletal muscle tissue constitutes fragmentations and the progression of cell death occurs from the tip and outer of the tail to its base. In addition, muscle cells apoptosis occurs first near the subepidermal fibrolast layer proposed that these cells may interfere the skeletal muscle cells apoptosis during the tail regression. When the of the glycosaminoglycan alterations of these different sizes of shortening tail was analyzed histochemically. After the Alcian Blue-Periodic Acid Schiff`s (AB-PAS sequences at critical electrolyte concentrations and different pH values, we observed carboxylated glycosaminoglycans (i.e., hyaluronic acid, HA are increased in apoptotic muscle cells throughout the tail regression. We concluded that carboxylated glycosaminglycans may play an important role in shortening of the tail via muscle cell apoptosis.

  20. Comparative Fine Structural Studies on the Adrenal Glands of the Toad, (Bufo tibamicus and the Desert Reptile, (Uromastyx philbyi

    S. A. Sakr

    2001-01-01

    Full Text Available fine structure of adrenal gland in the toad, (Bufo tibamicus and the desert reptile, (Uromastyx philbyi. The adrenal glands of both animals are composed of adrenocortical and chromaffin tissues. In B. tibamicus, The adrenocortical tissue is comprised of two main types of cells, the steroid cells with abundance of lipid inclusions and eosinophilic cells with eosinophilic granular cytoplasm. The chromaffin tissue is intermingled with adrenocortical tissue. They are formed of adrenaline and nor-adrenaline secreting cells with different electron density and variable sizes. The adrenocortical cells of U. phiblyi constituent the main bulk of the inner gland and they are typical steroid-secreting cells. They also characterized by their rich amount of lipid droplets. Cords or islets of inner chromaffin cells are scattered throughout the adrenocortical cells. The outer portion of the gland is composed of chromaffin cells surrounded by the capsule. Adrenaline and nor-adrenaline secreting cells were distinguished by means of different electron density of their chromaffin granules either in the outer or inner portion of the gland.

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

    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.

  2. Malformations of the regenerating optic tectum of larvae of the Egyptian toad, Bufo regularis Reuss.

    Abdel-Karim, A E

    1990-01-01

    Morphological and histological abnormalities were observed in the regenerating optic tecta of Bufo regularis larvae after partial excision of the left tectum and total excision of the right tectum. They were found in both the left and the right tectum. Invagination of the tectal tissue into the optic ventricle, masses of blood capillaries and gaps or cavities in the tectal tissue were observed. The size of the optic tecta was reduced and the shape and structure of the dorsal aspect of the midbrain were highly anomalous. PMID:2210507

  3. Antibacterial activity of the parotid glands secretions of sudanese indigenous african toad (Bufo spp.)

    The study revealed a well-built first line innate immunity system in Bufo Spp., the skin extracts illustrated a very active antibiotic attitude which inhibited the growth of human pathogenic bacteria species, Escherichia coli (ATCC 19615), staphylococcus aureus(ATCC29213) and streptococcus pyogenes (ATCC25922). Heat treatment of secretion supported the fact that the antibacterial components possess an enzymatic attitude. Gel filtration chromatography accompanied with sensitivity tests against S.aureus showed the existence of four groups responsible for antibacterial activity in the parotoid glands secretions.(Author)

  4. Helminth community structure in tadpoles of northern leopard frogs (Rana pipiens) and Woodhouse's toads (Bufo woodhousii) from Nebraska.

    Rhoden, Heather R; Bolek, Matthew G

    2015-12-01

    Currently, little information is available on helminth community structure in tadpoles, the ephemeral, feeding, non-reproductive larva stages of anurans. We examined the helminth community structure in tadpoles of northern leopard frogs, Rana pipiens, and Woodhouse's toads, Bufo woodhousii, from a first-order stream in Western Nebraska. Specifically, we were interested in how species-specific difference in size, time to metamorphosis, and habitat partitioning among larval anurans affect their helminth community structure. From June-July 2009, we collected 30 tadpoles of northern leopard frogs, R. pipiens, and 50 tadpoles of Woodhouse's toads, B. woodhousii, from Cedar Creek, Keith County, NE, USA. The compound helminth community was dominated by trematode metacercarial stages (echinostomatids and plagiorchids) and the nematode Gyrinicola batrachiensis with only a single non-gravid adult trematode, Gorgoderina attenuata, present in low numbers. The helminth component communities were depauperate and isolationist in nature, with a maximum of four helminth species/types per component community. Although no species-specific helminth infections were observed, clear differences were found in overall abundance of nematode versus trematode infections among tadpoles of these two anuran species. The component community of tadpoles of R. pipiens was dominated by nematodes, whereas the component community of tadpoles of B. woodhousii was dominated by trematodes. Although differences in tadpole susceptibility of these two anuran species could not be ruled out, differences in the reproductive strategy of G. batrachiensis in tadpoles of R. pipiens and B. woodhousii and anuran species-specific habitats partitioning among tadpoles of these two anuran species were important factors in structuring their helminth communities. Our study indicates that time to metamorphosis (older tadpoles) play a significant role in structuring helminth communities of tadpoles within species at the infracommunity level with older tadpoles having higher helminth species richness and/or abundances. However, species-specific differences in anuran tadpole habitat partitioning outweighed the effects of differences in time to metamorphosis at the component community level. Finally, our study is the first to report deformities in hind limb development in a tadpole from Nebraska. Of the 30 northern leopard frog tadpoles collected, a single individual contained an extra hind limb and was infected with two plagiorchid metacercariae located in the musculature above the hind limbs. PMID:26346456

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

    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.

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

    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.

  7. Interindividual variation of isolated muscle performance and fibre-type composition in the toad Bufo viridus.

    Wilson, Robbie S; James, Rob S; Kohlsdorf, Tiana; Cox, Valerie M

    2004-08-01

    Interindividual analyses of physiological performance represent one of the most powerful tools for identifying functional positive and negative linkages between various performance traits. In this study we investigated functional linkages in the whole-gastrocnemius performance of juvenile Bufo viridis by examining interindividual variation in in vitro muscle performance and muscle fibre-type composition. We used the work-loop technique to investigate the maximum in vitro power output and fatigue resistance of the gastrocnemius muscle during repeated sets of three cycles at the cycle frequency of 5 Hz, simulating an intermittent style of locomotion. We found several significant correlations between different measures of in vitro muscle performance, including a negative correlation between maximum net power output and fatigue resistance of power, indicating functional trade-offs between these performance traits. We also investigated the extent of individual variation in the proportions of different fibre types, and tested for correlations between individual variation in muscle fibre-type composition and the previously measured isolated muscle performance. Fast glycolytic fibres represented 84.0 +/- 3.4% of the muscle, while the combined slow oxidative and fast oxidative-glycolytic fibres represented 16 +/- 3.4%. We found no significant correlations between measures of in vitro muscle performance and the proportion of different fibre types in the gastrocnemius muscle. However, despite this lack of correlation between whole-muscle performance and muscle fibre-type composition data, we suggest the functional linkages detected between different measures of in vitro muscular performance have important ecological and evolutionary consequences. PMID:15185115

  8. Isolation and sequencing of doublesex/male abnormal 3 (DM related transcription factor (Dmrt genes from the Asian toad Bufo gargarizans (Cantor, 1842

    Wen Chen

    2007-01-01

    Full Text Available The doublesex/male abnormal 3 (dsx/mab-3 or DM domain gene family involved in sexual development encodes putative transcription factors including a DNA-binding homology motif, the DM domain. We used highly degenerate primers to clone and sequence seven distinct DM related transcription factor (Dmrt genes from the Asian toad (Bufo gargarizans Cantor, 1842. A database search for the cloned sequences revealed the following percentage identity with the homologous Dmrt genes of the human: BgDmrt1 = 97%, BgDmrt2 = 97%, three isoforms of BgDmrt3 (BgDmrt3a = 93%, BgDmrt3b = 95%, BgDmrt3c = 100% and two isoforms of BgDmrt5 (BgDmrt5 = 97%, BgDmrt5 = 91%. Based on DM domain amino acid sequence similarities we constructed a phylogenetic tree which grouped vertebrate and invertebrate Dmrt genes into seven distinct subfamilies. The DM domains of both human and the newly-discovered Bufo gargarizans genes contained two conserved zinc-chelating sites (CCHC and HCCC, except BgDmrt3b, which contained the CCRC and HCCC sites.

  9. The effect of soil composition and hydration on the bioavailability and toxicity of cadmium to hibernating juvenile American toads (Bufo americanus)

    The soil ecotoxicology literature has focused primarily on a few major taxa, to the neglect of other fossorial organisms such as amphibians. We selected cadmium (Cd) and the American toad (Bufo americanus) as a model contaminant and biological species to assess the impact of soil contamination on amphibian hibernation survival and post-hibernation condition. Soil sand composition (50, 70, 90%) and hydration (100, 150% water holding capacity (WHC)) were manipulated in addition to Cd concentration (0, 56, 165, 483 ?g/g) to determine whether these soil properties affect toxicity. Soil Cd concentration significantly reduced survival and locomotor performance, and was correlated negatively with percent mass loss and positively with whole body Cd concentration. Higher sand content resulted in less mass loss and greater Cd uptake. Toads that were hibernated in 50% sand hydrated to 100% WHC had higher survival, less mass loss, and better sprint performance than those hibernated in 50% sand, 150% WHC. This study demonstrates that concentrations of Cd found in soil at highly contaminated sites can be bioaccumulated by hibernating amphibians and may reduce fitness. Differences in microhabitat use may cause species to vary in their exposure and susceptibility to soil contamination. The toxicity of Cd to amphibians could be greater in natural systems where there are multiple stressors and fluctuations in environmental variables. - Capsule: The effect of cadmium-contaminated soils on hibernating amphibians depends on cadmium concentration and soil composition and moisture

  10. 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

    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 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

  11. Effects of glucagon, glucose, adrenaline and insulin infusion on blood glucose level in the common African toad (bufo regularis).

    Oyebola, D D; Ariwodola, J O; Alada, A R

    1998-01-01

    Male toads, weighing 70-123 g, were divided into 13 groups with 8 toad in each group. Animals in each group were fasted overnight before the experiments. Toads in groups 1 to 4 were infused for 30 minutes with adrenaline, 5 ugkg-1 min-1, glucose, 5.5 mg kg-1 min-1; glucagon 2 ugkg-1 min-1; and insulin 2000 uU kg-1 min-1, respectively. Blood samples for blood glucose measurement were taken before, during and after each infusion. The experiment was repeated in groups 5 and 6 using 3.5 mg kg-1 min-1 and 7.5 mg kg-1 min-1 of glucose respectively. Toads in groups 7 to 9 were pretreated with prazosin, 0.2 mg/kg and those in groups 10 to 12 were pretreated with propranolol, 0.5 mg/kg. After pretreatment, glucose, glucagon and insulin infusions were repeated in the alpha-blocked and beta-blocked toads, respectively. Group 13 was infused with 0.7% saline and served as the control. The results showed that infusions of adrenaline, glucose and glucagon resulted in significant hyperglycaemia while insulin caused hypoglycaemia. The hyperglycaemic response to glucose was dose-dependent. The experiments using blockers showed that the glycaemic effects of glucagon and insulin are mediated via beta adrenoceptors, that for glucose is via alpha adrenoceptors and from an earlier study, the glycaemic response of adrenaline is through both alpha and beta adrenoceptors. PMID:10456139

  12. Vitamin - a and limb regeneration in stages of the egyptian toad, bufo regularis Reuss-histological study

    Michael, M. I. [????? ???? ???????

    1995-01-01

    The histogenesis of regenerated limbs, of both control and treated /larvae/ with 30 I.U./ml of retinol palmitate for 3 days, was studied in two larval stages (viz. stages 53 & 54) of the anuran amphibian, Bufo regularis Reuss. Some histological changes took place in the amputated limbs of treated larvae in two phases: (a) during treatment and (b) after cessation of treatment and thereafter. In (a): the wound epidermal superficial layer became corrugated, basement membrane was not discernible,...

  13. Carcinogenic effect of force-feeding an extract of black pepper (Piper nigrum) in Egyptian toads (Bufo regularis).

    el-Mofty, M M; Khudoley, V V; Shwaireb, M H

    1991-01-01

    50 male and 50 female Bufo regularis were treated, by force-feeding, with an extract of black pepper, at a dose level of 2 mg, 3 times a week for 5 months. The first tumors appeared after 2 months. Liver tumors (hepatocellular carcinomas, lymphosarcomas and fibrosarcomas) were found in 12 males and 18 females. Metastatic deposits of hepatocellular carcinomas were registered in the spleen, kidney, fat body and ovary. PMID:1891179

  14. The action of parotoid venom on the heart of the toad (Bufo ictericus ictericus Spix 1824) and its effects on the inhibition caused by vagal stimulation.

    Pasquarelli, P; Mendes, E G; Sawaya, P

    1987-01-01

    1. The administration of crude venom of the parotoid glands of the toad Bufo ictericus ictericus to the in situ (via abdominal vein) or isolated heart of this anuran causes both chronotropic and inotropic effects. 2. While under action of parotoid venom, the heart of the animal is insensitive to vagus nerve stimulation. 3. This blocking of vagal action is dose dependent and it is suggested that it results from a functional antagonism between the venom constituents and the acetylcholine liberated by the nerve endings on stimulation. 4. The venom constituents probably involved in this antagonism are catecholamines (adrenaline and noradrenaline), tryptamine derivatives (serotonin and bufotenidin) and genins (bufagin and bufotoxin), possibly also ATP. 5. Adrenaline, noradrenaline and serotonin, or a mixture of the three, mimic, at least partially, the blocking of vagal action caused by crude venom. 6. The blocking action of crude venom can be prevented by previously or simultaneously adding acetylcholine to the infused crude venom. This prevention is dose dependent. 7. The blocking action persists in the boiled venom and in the material dialysed from crude venom. PMID:2888584

  15. Chloromyxum aegypticus n. sp. (Myxozoa: Chloromyxidae) infecting the testicular tissue of the Egyptian toad, Bufo regularis (Amphibia: Bufonidae), and its pathogenicity.

    Reda, Enayat Salem Ahmed

    2010-11-01

    A new myxosporean, Chloromyxum aegypticus n. sp., is described from the testes of the Egyptian toad Bufo regularis, captured from El Mansoura locality. C. aegypticus is identified on the basis of cytology, electron microscopy and histopathology. It is distinguished from all previously reported Chloromyxum spp. by its shape, dimensions of the mature spore (9.1 ± 0.1 (9.0-9.2) ?m in length? × 7.9 ± 0.1 (7.8-8.0) ?m in width), polar capsules, external ridge, sporoplasm nuclei, undulating suture, locality and host. Accumulation of several hundreds of plasmodia (0.8 ± 0.3 (0.5-1.1) mm in length × 0.5 ± 0.3 (0.2-0.7) mm in width) in the testes causes their enlargement. Parasites cause destruction of the seminiferous tubule cells and complete loss of spermatozoa. Since spermatogenesis stops, this seems to be a form of "parasitic castration". This is the first known record of the genus Chloromyxum in amphibian testes. PMID:20680336

  16. Variation in Developmental Duration and Metamorphosis of the Green Toad, Bufo viridis in Temporary Ponds as an Adaptation to Desert Environment

    Hussein H. K.

    2000-01-01

    Full Text Available The green toads, Bufo viridis breed in temporary desert ponds of variable duration and exhibit extreme plasticity in the timing of metamorphosis. Pond duration depended on initial depth and frequency of rainfall. Tadpoles in shorter duration ponds metamorphosed earlier than tadpoles in longer duration ponds. The larvae complete their development rapidly before the pond dried, but resulted in small size at metamorphosis. The effects of changing resource availability on the timing of metamorphosis were examined by raising the larvae in a factorial field experiment manipulating food level, larval density, and pond duration. At constant pond duration, tadpoles at constant high food level metamorphosed earlier at largest sizes. At low food level, tadpoles metamorphosed at a uniformly small size, but varied between treatments in the time required to reach that size. Tadpoles from both decreasing density and low food treatments metamorphosed earlier than tadpoles from increasing density and low food treatments. These results support the idea that tadpoles can respond adaptively to resource variation .

  17. Formation of multiple ependymas in the regenerating optic lobe of larvae of the Egyptian toad, Bufo regularis Reuss.

    Abdel-Karim, A E

    1990-01-01

    In the regenerating optic lobe of Bufo regularis larvae, secondary ependymas were formed in both the dorsal part (optic tectum) and ventral region (tegmentum) of the lobe concerned. These secondary ependymas were frequently observed in the rostral and caudal tectal regions after complete excision of the tectum. Most of the multiple ependymal structures were formed by self-organization of groups of undifferentiated cells migrating from the primary ependyma lining the optic tectum. Others split off from the primary ependyma, but remained in contact with it. The observations emphasize the wide range of possibilities of the cells produced by the larval tectal ependyma in response to partial or total excision of the tectum. The results suggest that cells of ependymal origin, in regenerating tectum, are capable of self-organization to complete ependymal tubes in the absence of direct with the primary ependyma. PMID:2210496

  18. Amputation level and hind limb regeneration in larvae of the Egyptian toad Bufo regularis Reuss: length, volume and rate.

    Abdel-Karim, A E

    1989-01-01

    Study of the influence of the amputation level on regeneration length and volume and on the rate of regeneration of the hind limbs of a larval stage of Bufo regularis revealed that, during dedifferentiation and blastema accumulation and growth, the parts regenerating from proximal and distal amputation levels were almost the same length and volume, and grew at the same rate, irrespective of the amputation level. During blastema differentiation and morphogenesis, however, there were significant length, volume and elongation rate differences between parts regenerating from different amputation levels. The results also demonstrated that there was a strong positive correlation between regeneration length and volume, but that the elongation rate was not correlated to regeneration volume. PMID:2606380

  19. Strong reproductive barriers in a narrow hybrid zone of West-Mediterranean green toads (Bufo viridis subgroup with Plio-Pleistocene divergence

    Perrin Nicolas

    2010-07-01

    Full Text Available Abstract Background One key question in evolutionary biology deals with the mode and rate at which reproductive isolation accumulates during allopatric speciation. Little is known about secondary contacts of recently diverged anuran species. Here we conduct a multi-locus field study to investigate a contact zone between two lineages of green toads with an estimated divergence time of 2.7 My, and report results from preliminary experimental crosses. Results The Sicilian endemic Bufo siculus and the Italian mainland-origin B. balearicus form a narrow hybrid zone east of Mt. Etna. Despite bidirectional mtDNA introgression over a ca. 40 km North-South cline, no F1 hybrids could be found, and nuclear genomes display almost no admixture. Populations from each side of the contact zone showed depressed genetic diversity and very strong differentiation (FST = 0.52. Preliminary experimental crosses point to a slightly reduced fitness in F1 hybrids, a strong hybrid breakdown in backcrossed offspring (F1 x parental, with very few reaching metamorphosis and a complete and early mortality in F2 (F1 x F1. Conclusion Genetic patterns at the contact zone are molded by drift and selection. Local effective sizes are reduced by the geography and history of the contact zone, B. balearicus populations being at the front wave of a recent expansion (late Pleistocene. Selection against hybrids likely results from intrinsic genomic causes (disruption of coadapted sets of genes in backcrosses and F2-hybrids, possibly reinforced by local adaptation (the ranges of the two taxa roughly coincide with the borders of semiarid and arid climates. The absence of F1 in the field might be due to premating isolation mechanisms. Our results, show that these lineages have evolved almost complete reproductive isolation after some 2.7 My of divergence, contrasting sharply with evidence from laboratory experiments that some anuran species may still produce viable F1 offspring after > 20 My of divergence.

  20. Chloride channels in toad skin

    Larsen, Erik Hviid; Rasmussen, B E

    1982-01-01

    A study of the voltage and time dependence of a transepithelial Cl- current in toad skin (Bufo bufo) by the voltage-clamp method leads to the conclusion that potential has a dual role for Cl- transport. One is to control the permeability of an apical membrane Cl-pathway, the other is to drive Cl...

  1. 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

    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.

  2. 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...

  3. The genetics of amphibian declines: Population substructure and molecular differentiation in the Yosemite Toad, Bufo canorus (Anura, Bufonidae) based on single-strand conformation polymorphism analysis (SSCP) and mitochondrial DNA sequence data

    Bradley, Shaffer H.; Fellers, G.M.; Magee, A.; Randal, Voss S.

    2000-01-01

    We present a comprehensive survey of genetic variation across the range of the narrowly distributed endemic Yosemite toad Bufo canorus, a declining amphibian restricted to the Sierra Nevada of California. Based on 322 bp of mitochondrial cytochrome b sequence data, we found limited support for the monophyly of B. canorus and its closely related congener B. exsul to the exclusion of the widespread western toad B. boreas. However, B. exsul was always phylogenetically nested within B. canorus, suggesting that the latter may not be monophyletic. SSCP (single-strand conformation polymorphism) analysis of 372 individual B. canorus from 28 localities in Yosemite and Kings Canyon National Parks revealed no shared haplotypes among these two regions and lead us to interpret these two parks as distinct management units for B. canorus. Within Yosemite, we found significant genetic substructure both at the level of major drainages and among breeding ponds. Kings Canyon samples show a different pattern, with substantial variation among breeding sites, but no substructure among drainages. Across the range of B. canorus as well as among Yosemite ponds, we found an isolation-by-distance pattern suggestive of a stepping stone model of migration. However, in Kings Canyon we found no hint of such a pattern, suggesting that movement patterns of toads may be quite different in these nearby parklands. Our data imply that management for B. canorus should focus at the individual pond level, and effective management may necessitate reintroductions if local extirpations occur. A brief review of other pond-breeding anurans suggests that highly structured populations are often the case, and thus that our results for B. canorus may be general for other species of frogs and toads.

  4. Nomenclatural availability of the names applied to “varieties” of the green toad (Bufo viridis subgroup in the Italian territory, with emphasis on the variety lineata of Ninni (Anura: Bufonidae

    Nicola Novarini

    2010-07-01

    Full Text Available Recent molecular investigations on Eurasian green toads led to the recognition of distinct lineages and to the establishment of new taxa within the former Bufo viridis; as a consequence, significant range-wide nomenclatural changes have been proposed, although some uncertainties remained on the available names applicable within the Italian territory. In order to contribute to clarify the matter, we evaluated, under the provisions of the International Code of Zoological Nomenclature, the nomenclatural availability of all the names that have been applied to infrasubspecific entities of the Bufo viridis subgroup within the Italian territory. We also provided a historical overview of the usage of all these names, as well as detailed information on the original material upon which the variety lineata of A.P. Ninni was established. Our analysis supports the view that only the names crucigera Eichwald, 1831 and balearica Boettger, 1880 are available, the former being however junior synonym of B. viridis Laurenti, 1768, whereas the names acutirostris and obtusirostris of Lessona, lineata of Ninni, concolor and maculata of Camerano, and nardoi of Paolucci, Fuhn and Bruno are all not available.

  5. Assessing atrazine-induced toxicities in Bufo bufo gargarizans Cantor.

    Sai, Linlin; Wu, Qingbo; Qu, Binpeng; Bo, Cunxiang; Yu, Gongchang; Jia, Qiang; Xie, Lin; Li, Yuezhong; Guo, Qiming; Ng, Jack C; Peng, Cheng

    2015-02-01

    Atrazine (AZ), a widely used herbicide has drawn attentions for its potential impacts on amphibians. This study aims to investigate the toxicity of AZ in Bufo bufo gargarizans Cantor (B. bufo gargarizans), a species of toad commonly found in China and countries in East Asia. We treated tadpoles with 0.1, 1, 10 and 100 μg/L AZ for 85 days and examined related parameters. The results showed that the mortality of the toads in the treatment group increased dramatically in a U-shaped dose-response relationship. The hindlimb extension and metamorphosis rate of the toads were significantly inhibited by AZ at 10 and 100 μg/L. Under the same condition, there were significant progressive changes in the testicular structures. Moreover, we found that AZ has no significant effects on growth, sex ratios, gonadal morphology, forelimb emergence and histology in the ovaries. Our results support the idea that environmental contaminants including AZ may be relevant to global amphibian decline. PMID:25533566

  6. The use of the chelating agent EDTA in the treatment of acute cadmium toxicity, tissue distribution and some blood parameters in the Egyptian toad Bufo regularis.

    Hilmy, A M; el-Domiaty, N A; Daabees, A Y; Abou Taleb, E M

    1986-01-01

    Erythrocyte count, haemoglobin content, haematocrit value, erythrocyte sedimentation rate and cadmium accumulation in some organs and tissues were estimated in toads administered 6.2 mg Cd2+/kg i.m. for 4 days. EDTA therapy caused considerable decrease in all the blood parameters studied. A striking reduction in the cadmium content of all the organs and tissues studied except the kidneys was also observed after simultaneous treatment with EDTA. PMID:2877808

  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

    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.

  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

    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...

  9. Age and Growth of the Green Toad, Bufo viridis (Laurenti, 1768 from an Island and a Mainland Population in Giresun, Turkey

    Handan Karaoglu

    2011-01-01

    Full Text Available Age structure and some growth parameters of Bufo viridis from the Giresun Island and Giresun province in Turkey were studied by skeletochronology. We studied 56 specimens (41 female, 15 male from island and 44 (5 female, 39 male from mainland population. In both populations, age at sexual maturity was 2-3 years in both males and females. Age was ranged from 2-8 years for females and 3-6 years for males in island while 4-7 and 3-8 years in mainland population, respectively. Males and females did not differ in the mean age while SVL and weight were significantly different between males and females in two populations. In addition, we found positive correlations between age and SVL in both sexes in two populations.

  10. The Effect of the Ecology of Toads on the Distribution of Helminths

    VASHETKO, Emilia V.; SIDDIKOV, Bakhodir H.

    1999-01-01

    This paper presents the results of studies on the helminth fauna of the green toad, Bufo viridis, in Uzbekistan. Twently helminth species were identified. The highest diversity of helminths was recorded in toads in the newly-built districts of Tashkent (1966-76). The helminth fauna of the toads inhabiting foothills was less common.

  11. Testicular myxosporidiasis and ultrastructural characteristics of Myxobolus bufonis (Myxobolidae) infecting the Egyptian toad Bufo regularis (Bufonidae). A light and electron microscopic study.

    Morsy, Kareem; Semmler, Margit; Al-Olayan, Ebtsam; Mehlhorn, Heinz

    2015-11-01

    The phylum Myxozoa comprises more than 2180 species, almost all of which are considered to be obligate parasites of aquatic fishes and amphibians. They are dangerous pathogens responsible for severe economic losses. From March to September 2014, 40 adult male Bufo regularis (Bufonidae) captured from different areas at Giza province, Egypt, were surveyed for myxosporean parasitic infection. Of these, 22 (55%) were infected by histozoic plasmodia, which produced spores after rupture belonging to Myxosporidia. The present investigation introduced a new data for the recorded parasite observed by light and transmission electron microscopy. The infection was diagnosed as large clusters of macroscopic plasmodia embedded in the testicular tissue causing distortion at the site of infection. The host reaction was manifested by the encapsulation of the plasmodia with a thick layer of connective tissue. Plasmodia were whitish in color, elliptical to ovoid in shape measuring 0.54?±?0.2 (0.34-0.63) mm in diameter. The spores were subspherical, reaching 7.1?±?0.2 (6.2-8.4) ?m in length and 6.3?±?0.2 (5.8-7.0) ?m in width with two equal-sized polar capsules regularly arranged at the anterior pole of each spore. They were 3.4?±?0.2 (3.0-4.2) ?m in length and 1.9?±?0.2 (1.6-2.4) in width with 6-8 turns of polar filaments. Ultrastructural analysis showed that the plasmodia were surrounded by a plasma membrane with numerous projections and pinocytotic channels extended toward the host cell. The generative cells and the different developmental stages were arranged at the periphery of the plasmodia while immature and mature spores were centrally arranged. Sporogenesis, capsulogenesis, valvogenesis, and spore maturation of the present parasite were also described. PMID:26266882

  12. Effect of cholic acid on tumor in the Egyptian toad.

    Sadek, I A

    1986-01-01

    Egyptian toads, Bufo regularis, were fed with cholic acid (sodium salt) 3 times/week for 12 weeks at different dose levels (2.5, 5, and 10 mg/toad). Results obtained showed only 1 case in both the 5 and 10 mg/toad doses that gave a tumor. Toads receiving N-methyl-N-nitrosourea (MNU) 1 mg/toad, 3 times/week for 12 weeks had 36% ileum tumors (18 toads out of 50, without mortality). On the other hand, a higher dose of MNU (5 mg/toad) caused 50% mortality in the experimental animals. Toads treated with MNU at a dose level of 1 mg/toad were subjected to CA at dose levels of 2.5, 5, 10 mg/toad. They showed a 48, 66 and 76% higher incidence of ileum tumors at the three different dose levels, respectively. It is concluded that cholic acid has a promoting effect on ileum tumor evoked by MNU in toads as in mammals. PMID:3725289

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

    Coelho F. C.; Smatresk N. J.

    2003-01-01

    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 showe...

  14. Radiosensitivity of the Philippine giant toad (Bufu marinus L.)

    The Philippine giant toad (Bufu marinus L.) were studied to establish their radiosensitivities and their possible use as a good biological indicator organism of radiation effects. Live male and female toads were exposed to ionizing doses of gamma irradiation. Chromosome analysis was done under the Carl Zeiss III photo microscope. Somatic and meiotic chromosome aberrations were induced in giant toad upon in vivo whole gamma irradiations. By cytogenetic analysis the aberrant chromosomes were observed and evaluated. In these studies, it was concluded that Bufo marinus L. is significantly radiosensitive and a good biological indicator organisms of radiation effects. (ISD). 2 figs.; 8 tabs

  15. Impact of invasive cane toads on Australian birds.

    Beckmann, Christa; Shine, Richard

    2009-12-01

    The cane toad (Bufo marinus), a large, toxic, American anuran, was introduced to Australia in 1935. Populations of many of Australia's reptiles (snakes, varanid lizards, crocodiles) and carnivorous mammals (dasyurid marsupials) have declined because these predators are killed by the toad's powerful toxins. In contrast to these well-studied species, little is known about the cane toads impacts on Australian birds. We reviewed published and unpublished data on behavioral interactions between Australian avian predators and cane toads and collated distributional and dietary information to identify avian taxa potentially at risk from cane toad invasion. Cane toads are sympatric with 172 frog-eating bird species in Australia, and an additional 8 bird species overlap with the predicted future range of the toad. Although many bird species thus are potentially at risk, behavioral observations suggest the risk level is generally low. Despite occasional reports of Australian birds being killed when they ingest cane toads, most birds either ignore toads or survive the predation event. The apparently higher tolerance of Australian birds to toad toxins, compared with Australian reptiles and marsupials, may reflect genetic exchange between Australian birds and Asian populations that encounter other bufonid species regularly and hence have evolved the capacity to recognize or tolerate this toxic prey. PMID:19508674

  16. DIET OF THE SOUTHERN TOAD FROM THE SOUTHERN EVERGLADES

    We examined the diet of a February-May sample of the southern toad (Bufo Terrestris) from the Everglades National Park. Above the familial level, 13 taxa were consumed, but ants (Hymenoptera) and beetles (Coleoptera) were consumed most by, and in the greatest number of s...

  17. Phylogeography of Bufo marinus from its natural and introduced ranges.

    SLADE, R. W.; C. Moritz

    1998-01-01

    The marine toad, Bufo marinus, has a broad natural distribution extending from the south-west of the USA to southern Peru and the central Amazon. It was introduced to several localities in the Caribbean and Pacific Oceans to control sugar cane pests. We sequenced 468 bp of mitochondrial DNA (mtDNA) containing the ND3 gene, and flanking tRNA genes from toads spanning the broad natural and introduced ranges. Consistent with the known history of introductions and expected effects of serial bottl...

  18. Phylogenetic studies on the architectural features of Amphibian {bufo regularis) and mammalian (oryctolagus cuniculus) kidneys

    El Gohary, Z. M. A. [???? ????? ???? ???????

    1994-01-01

    The results of the present study revealed that mesonephric and metanephric kidneys of both the anamniotes (Bufo regularis) and the amniotes (Oryctolagus cuniculus) vertebrates respectively differ morphologically, anatomically and histologically. The structural organization of toad and rabbit kidneys was studied with the light microscope (LM) along with a microdissection technique. In the toad, the kidneys are paired attenuate mesonephric organs and have mesonephric segmental construction. On ...

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

    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

  20. Demography of common toads after local extirpation of co-occurring midwife toads

    Bosch, Jaime; Fernandez-Beaskoetxea, S; Scherer, R.; Amburgey, Staci; Muths, Erin L.

    2014-01-01

    Estimating demographic parameters like survival or recruitment provides insight into the state and trajectory of populations, but understanding the contexts influencing those parameters, including both biotic and abiotic factors, is particularly important for management and conservation. At a high elevation national park in Central Spain, common toads (Bufo bufo) are apparently taking advantage of the near-extirpation of the midwife toad (Alytes obstetricans), as colonization into new breeding ponds is evident. Within this scenario, we expected demographic parameters of common toad populations tobe affected favorably by the putative release from competition. However, we found the population growth rate was negative in 4 of 5 years at the long-standing population; survival probability at the long-standing population and newly-colonised breeding ponds was lower than reported for other toads living at high elevations and the probability of recruitment was inadequate to compensate for the survival rate in maintaining a positive trajectory for either of the breeding ponds. We assessed weather covariates and disease for their contribution to the context that may be limiting the common toad’s successful use of the niche vacated by the midwife toad.

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

    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...

  2. Diet composition of the invasive cane toad (Chaunus marinus) on Rota, Northern Mariana Islands

    Reed, R.N.; Bakkegard, K.A.; Desy, G.E.; Plentovich, S.M.

    2007-01-01

    The cane or marine toad (Chaunus marinus, formerly Bufo marinus) was introduced to the Northern Mariana Islands starting in the 1930s. The effects of this exotic predator on native vertebrates (especially lizards) are largely unknown. We analysed the stomach contents of 336 cane toads collected from the island of Rota, with the goal of estimating the level of toad predation on native vertebrates. Beetles, ants, millipedes, and grasshoppers/crickets comprised the majority of prey classes consumed by toads. The introduced Brahminy blindsnake (Ramphotyphlops braminus; N = 6) and conspecific cane toads (N = 4) were the vertebrates most commonly found in toad stomachs. Skinks (Emoia; N = 2) were the only native vertebrates represented in our sample. The small numbers of nocturnal terrestrial vertebrates native to Rota likely translates to relatively low rates of predation by cane toads on native vertebrates.

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

    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...... system of the red cell membrane accounts for our findings, and for an inwardly directed active Cl- flux in terms of Cl-/HCO3- exchange....

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

    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...

  5. Fatal attraction: adaptations to prey on native frogs imperil snakes after invasion of toxic toads

    Hagman, Mattias; Phillips, Benjamin L.; Shine, Richard

    2009-01-01

    Adaptations that enhance fitness in one situation can become liabilities if circumstances change. In tropical Australia, native snake species are vulnerable to the invasion of toxic cane toads. Death adders (Acanthophis praelongus) are ambush foragers that (i) attract vertebrate prey by caudal luring and (ii) handle anuran prey by killing the frog then waiting until the frog's chemical defences degrade before ingesting it. These tactics render death adders vulnerable to toxic cane toads (Bufo...

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

    Phalen David N; Hartigan Ashlie; Å lapeta Jan

    2010-01-01

    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 ...

  7. Improvement in detecting the carcinogenicity of bracken fern using an Egyptian toad.

    El-Mofty, M M; Sadek, I A; Bayoumi, S

    1980-01-01

    Neoplasms developed in 18 of 98 toads, Bufo regularis, subjected to enforced feeding with bracken fern. They comprise 7 cases of adenocarcinoma in the ileum, 16 cases of hepatomas in the liver and 6 cases of neoplasms in the kidney due to metastases from the hepatomas. The results demonstrate that the Egyptian toad can be considered as an advantageous model for detecting the carcinogenicity of bracken fern, since the lesions occur faster than in other experimental animals. PMID:7432754

  8. Indirect evidence for elastic energy playing a role in limb recovery during toad hopping

    Schnyer, Ariela; Gallardo, Mirialys; Cox, Suzanne; Gillis, Gary

    2014-01-01

    Elastic energy is critical for amplifying muscle power during the propulsive phase of anuran jumping. In this study, we use toads (Bufo marinus) to address whether elastic recoil is also involved after take-off to help flex the limbs before landing. The potential for such spring-like behaviour stems from the unusually flexed configuration of a toad's hindlimbs in a relaxed state. Manual extension of the knee beyond approximately 90° leads to the rapid development of passive tension in the lim...

  9. Active urea transport by the skin of Bufo viridis: Amiloride- and phloretin-sensitive transport sites

    Urea is actively transported inwardly (Ji) across the skin of the green toad Bufo viridis. Ji is markedly enhanced in toads adapted to hypertonic saline. The authors studied urea transport across the skin of Bufo viridis under a variety of experimental conditions, including treatment with amiloride and phloretin, agents that inhibit urea permeability in the bladder of Bufo marinus. Amiloride (10-4 M) significantly inhibited Ji in both adapted and unadapted animals and was unaffected by removal of sodium from the external medium. Phloretin (10-4 M) significantly inhibited Ji in adapted animals by 23-46%; there was also a reduction in Ji in unadapted toads at 10-4 and 5 x 10-4 M phloretin. A dose-response study revealed that the concentration of phloretin causing half-maximal inhibition (K1/2) was 5 x 10-4 M for adapted animals. Ji was unaffected by the substitution of sucrose for Ringer solution or by ouabain. They conclude (1) the process of adaptation appears to involve an increase in the number of amiloride- and phloretin-inhibitable urea transport sites in the skin, with a possible increase in the affinity of the sites for phloretin; (2) the adapted skin resembles the Bufo marinus urinary bladder with respect to amiloride and phloretin-inhibitable sites; (3) they confirm earlier observations that Ji is independent of sodium transport

  10. Effects of endosulfan pesticide on toad.

    Isioma, Tongo; Lawrence, Ezemonye

    2013-02-01

    The lethal and sublethal toxicity of Endosulfan on the African toad, Bufo regularis were evaluated to assess changes in behaviour and energy reserves. 96 hours LC50 was 0.730 mg/l while the estimated safe concentration was 0.07 mg/L indicating the high toxicity of the insecticide. Toads exposed to lethal concentrations of endosulfan showed dose-dependent behavioural abnormalities with more pronounced poisoning symptoms occurring at higher concentrations. The pesticide caused differential increase in serum glucose levels with a concomitant reduction in liver glycogen indicating disorders in carbohydrate metabolism due to pesticide induced stress and hence can serve as suitable biomarkers in pesticide toxicity studies. PMID:23631157

  11. Short-term studies of the effect of acrylamide on the testes of the Egyptian toad.

    Sadek, I A

    1989-01-01

    The treatment of male Egyptian toads (Bufo regularis) with acrylamide (1 mg/toad twice a week for four weeks) was followed by atrophy of the testes, inhibition of spermatogenesis and necrosis of the seminiferous tubules with signs of vacuolation. Ultrastructurally, the Leydig cells of treated toads displayed varying degrees of vacuolation of the mitochondria, with a decrease in the number of ribosomes. The mechanism of the action of acrylamide in inhibiting spermatogenesis may be due to a decrease in the testosterone level, as borne out by vacuolation of the mitochondria and the decrease in the ribosomes in the Leydig cells of treated animals. PMID:2634605

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

    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.

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

    Phillips, Ben L; Shine, Richard

    2006-06-22

    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 and a decreased preference for toads as prey. Separate laboratory experiments suggest that these changes are not attributable to learning (we were unable to teach naive snakes to avoid toxic prey) or to acquired resistance (repeated sub-lethal doses did not enhance resistance). These results strongly suggest that black snake behaviour and physiology have evolved in response to the presence of toads, and have done so rapidly. Toads were brought to Australia in 1935, so these evolved responses have occurred in fewer than 23 snake generations. PMID:16777750

  14. Death of a South American fur seal (Arctocephalus australis) after the ingestion of toads--evaluation of toad poisoning by toxicological analysis.

    Toennes, Stefan W; Peters, Martin; Osmann, Christine; Pogoda, Werner; Mebs, Dietrich

    2015-01-01

    Animals in zoological gardens are at risk of severe and even lethal poisoning when they accidentally ingest toads. Here we report the case of an eleven month old male South American fur seal (Arctocephalus australis) which was found dead in its outdoor enclosure in the zoo of Dortmund, Germany. Autopsy revealed the presence of two adult, partly digested common toads (Bufo bufo) in the stomach. Toxicological analysis of the stomach content using high performance liquid chromatography coupled to time-of-flight mass spectrometry (LC-TOF MS) proved the presence of bufadienolides, the major cardiotoxic components of toad poisons. Using electrochemical luminescens immunoassay (ECLIA) compounds equivalent to digitoxin were detected in the blood sample confirming the absorption of toad poison components from the intestines into the circulation potentially leading to cardiac failure. In zoological gardens special precautions are necessary to protect non-native animals from encountering toads and the risk of poisoning, particularly in early spring, the spawning period of the toads. PMID:26054232

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

    NWORAH DC, OLORUNFEMI OJ

    2011-01-01

    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) par...

  16. Resting respiratory behavior in minimally instrumented toads - effects of very long apneas on blood gases and pH Comportamento respiratório em repouso de sapos minimamente implantados - efeitos de apnéias de longa duração sobre o pH e gases sanguíneos

    F. C. Coelho; N. J. Smatresk

    2003-01-01

    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 showe...

  17. Repetitive DNA and Feulgen hydrolysis kinetics in three species of Bufo.

    Pellicciari, C; Bachmann, K

    1979-01-01

    Two North American species of the genus Bufo (Bufo cognatus and Bufo boreas, 2n = 22) and one African species (Bufo regularis, 2n = 20) were analyzed with respect to their repetitive DNA fractions and the behaviour of their chromatin to the acid hydrolysis at different times. The mean melting point of the total isolated DNA decreased from 89 degrees C to 87 degrees C with a genome size increase from 4.4 to 7.5 pg. The differences in genome size can only partly be explained on the basis of repetitive DNA fractions (renaturing up to Cot 10 in 0.12 M phosphate buffer). Several fractions in this repetitive range behave independently in the three species and the spectrum of repetitive fractions in the African Bufo regularis differs distinctly from those of the American toads. When fixed chromatin of these species in histochemical preparations is hydrolyzed with 5N HCl during the Feulgen reaction, the kinetics of depurination are equal in all species, while hydrolytic DNA breakdown proceeds distinctly more slowly in Bufo reularis as compared to the other species. PMID:93962

  18. Toad envenoming in dogs: effects and treatment

    M. SAKATE

    2000-01-01

    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 their 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.

  19. Adapting to an invasive species: toxic cane toads induce morphological change in Australian snakes.

    Phillips, Ben L; Shine, Richard

    2004-12-01

    The arrival of invasive species can devastate natural ecosystems, but the long-term effects of invasion are less clear. If native organisms can adapt to the presence of the invader, the severity of impact will decline with time. In Australia, invasive cane toads (Bufo marinus) are highly toxic to most snakes that attempt to eat them. Because snakes are gape-limited predators with strong negative allometry for head size, maximum relative prey mass (and thus, the probability of eating a toad large enough to be fatal) decreases with an increase in snake body size. Thus, the arrival of toads should exert selection on snake morphology, favoring an increase in mean body size and a decrease in relative head size. We tested these predictions with data from specimens of four species of Australian snakes, collected over >80 years. Geographic information system layers provided data on the duration of toad exposure for each snake population, as well as environmental variables (latitude, precipitation, and temperature). As predicted, two toad-vulnerable species (Pseudechis porphyriacus and Dendrelaphis punctulatus) showed a steady reduction in gape size and a steady increase in body length with time since exposure to toads. In contrast, two species at low risk from toads (Hemiaspis signata and Tropidonophis mairii) showed no consistent change in these morphological traits as a function of the duration of toad exposure. These results provide strong evidence of adaptive changes in native predators as a result of the invasion of toxic prey. PMID:15569943

  20. Fatal attraction: adaptations to prey on native frogs imperil snakes after invasion of toxic toads.

    Hagman, Mattias; Phillips, Benjamin L; Shine, Richard

    2009-08-01

    Adaptations that enhance fitness in one situation can become liabilities if circumstances change. In tropical Australia, native snake species are vulnerable to the invasion of toxic cane toads. Death adders (Acanthophis praelongus) are ambush foragers that (i) attract vertebrate prey by caudal luring and (ii) handle anuran prey by killing the frog then waiting until the frog's chemical defences degrade before ingesting it. These tactics render death adders vulnerable to toxic cane toads (Bufo marinus), because toads elicit caudal luring more effectively than do native frogs, and are more readily attracted to the lure. Moreover, the strategy of delaying ingestion of a toad after the strike does not prevent fatal poisoning, because toad toxins (unlike those of native frogs) do not degrade shortly after the prey dies. In our laboratory and field trials, half of the death adders died after ingesting a toad, showing that the specialized predatory behaviours death adders use to capture and process prey render them vulnerable to this novel prey type. The toads' strong response to caudal luring also renders them less fit than native anurans (which largely ignored the lure): all toads bitten by adders died. Together, these results illustrate the dissonance in behavioural adaptations that can arise following the arrival of invasive species, and reveal the strong selection that occurs when mutually naive species first interact. PMID:19419984

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

    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

  2. Mapping the Relative Probability of Common Toad Occurrence in Terrestrial Lowland Farm Habitat in the United Kingdom

    Salazar, Rosie D.; Montgomery, Robert A.; Thresher, Sarah E.; Macdonald, David W.

    2016-01-01

    Introduction The common toad (Bufo bufo) is of increasing conservation concern in the United Kingdom (UK) due to dramatic population declines occurring in the past century. Many of these population declines coincided with reductions in both terrestrial and aquatic habitat availability and quality and have been primarily attributed to the effect of agricultural land conversion (of natural and semi-natural habitats to arable and pasture fields) and pond drainage. However, there is little evidence available to link habitat availability with common toad population declines, especially when examined at a broad landscape scale. Assessing such patterns of population declines at the landscape scale, for instance, require an understanding of how this species uses terrestrial habitat. Methods We intensively studied the terrestrial resource selection of a large population of common toads in Oxfordshire, England, UK. Adult common toads were fitted with passive integrated transponder (PIT) tags to allow detection in the terrestrial environment using a portable PIT antenna once toads left the pond and before going into hibernation (April/May-October 2012 and 2013). We developed a population-level resource selection function (RSF) to assess the relative probability of toad occurrence in the terrestrial environment by collecting location data for 90 recaptured toads. Results The predicted relative probability of toad occurrence for this population was greatest in wooded habitat near to water bodies; relative probability of occurrence declined dramatically > 50 m from these habitats. Toads also tended to select habitat near to their breeding pond and toad occurrence was negatively related to urban environments. PMID:26841108

  3. ENVENENAMENTO DE CÃES POR BUFADIENOLÍDEOS (Substâncias encontradas na secreção das glândulas paratóides dos sapos do gênero Bufo POISONING OF DOGS BY BUFADIENOLIDES (SUBSTANCES FOUND IN THE PARATOID GLAND SECRETION OF FROGS OF THE GENUS Bufo

    Lourival Pereira Nunes

    2007-09-01

    Full Text Available

    Os autores estudaram o efeito da aplicação na mucosa bucal de cães, do produto secretado pelas glândulas paratóides de sapos do gênero Bufo. Os cães apresentaram sinais de graves intoxicações, imediatamente após a aplicação do referido produto.

    In the present paper, the authors report the effects of toad’s poison in dogs. This is the first case describe in Goiás.

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

    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

  5. Adapting to an invasive species: Toxic cane toads induce morphological change in Australian snakes

    Phillips, Ben L; Shine, Richard

    2004-01-01

    The arrival of invasive species can devastate natural ecosystems, but the long-term effects of invasion are less clear. If native organisms can adapt to the presence of the invader, the severity of impact will decline with time. In Australia, invasive cane toads (Bufo marinus) are highly toxic to most snakes that attempt to eat them. Because snakes are gape-limited predators with strong negative allometry for head size, maximum relative prey mass (and thus, the probability of eating a toad la...

  6. Evidence for chromosome and Pst I satellite DNA family evolutionary stasis in the Bufo viridis group (Amphibia, Anura).

    Odierna, Gaetano; Aprea, Gennaro; Capriglione, Teresa; Castellano, Sergio; Balletto, Emilio

    2004-01-01

    The West Palearctic green toads, Bufo viridis , represent a species complex. Apart from tetraploid populations, which form at least one separate species, evidence exists for relevant differentiation among diploid populations. We present the results of a chromosomal (C-, Ag-NOR-, Replication pattern, DAPI and CMA3 banding) and molecular study (isolation and characterization of a satellite DNA family) carried out on a number of Central Asian, European and North African populations. For comparative purposes, our molecular analysis was also extended to specimens of three additional Bufo species (B. bufo, B. mauritanicus and B. cf. regularis ), as well as two rare African bufonids (Werneria mertensis and Wolterstoffina sp.). Our results demonstrate a remarkable karyological and molecular evolutionary stasis in the Bufo viridis complex. In fact, all chromatinic markers showed the same pattern and/or composition in all specimens, independently of their origin and ploidy levels. Even the NOR loci were invariably two and located on the telomeric regions of two chromosomes of the sixth pair, or quartet. Furthermore, very similar patterns of genomic hybridization of a monomeric unit of the Pst I satellite DNA family (named pBv) were observed in all diploid and tetraploid populations, as well as in B. bufo and B. mauritanicus . Finally, pBv hybridizes with monomeric units of Pst I satellite DNA in all species studied, including Werneria and Wolterstorffina, which are thought to have separated from Bufo as early as in the Mesozoic. PMID:15505402

  7. Induction of leukaemia in chloramphenicol-treated toads.

    el-Mofty, M M; Abdelmeguid, N E; Sadek, I A; Essawy, A E; Aleem, E A

    2000-01-01

    Chloramphenicol has been associated with the development of aplastic anaemia. As it is still widely used in Egypt, we studied its effect on 100 Egyptian toads (Bufo regularis) given a dose of chloramphenicol of 5 mg/40 g body weight for 12 weeks. We found it induced numerous, severe ultrastructural changes in almost all types of leukocytes. These changes were similar to those induced by the chemical carcinogen 7,12-dimethylbenz(a)anthracene in 100 toads used as the carcinogen control group, and similar to those in leukocytes reported in humans with leukaemia. We recommend regulations be applied on the use of this antibiotic in countries where it is still widely used. PMID:12197324

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

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

    2010-01-01

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

  9. Magnetic orientation of the Common Toad: establishing an arena approach for adult anurans

    Gollmann Günter

    2011-03-01

    Full Text Available Abstract Background Magnetic orientation is a taxonomically widespread phenomenon in the animal kingdom, but has been little studied in anuran amphibians. We collected Common Toads (Bufo bufo during their migration towards their spawning pond and tested them shortly after displacement for possible magnetic orientation in arena experiments. Animals were tested in two different set-ups, in the geomagnetic field and in a reversed magnetic field. To the best of our knowledge, this is the first study testing orientation of adult anurans with a controlled magnetic field of a known strength and alignment. Results After displacement, toads oriented themselves unimodally under the geomagnetic field, following their former migration direction (d-axis. When the magnetic field was reversed, the distribution of bearings changed from a unimodal to a bimodal pattern, but still along the d-axis. The clustering of bearings was only significant after the toads reached the outer circle, 60.5 cm from their starting point. At a virtual inner circle (diameter 39 cm and at the start of the experiment, orientation of toads did not show any significant pattern. Conclusions The experimental set-up used in our study is suitable to test orientation behaviour of the Common Toad. We speculate that toads had not enough time to relocate their position on an internal map. Hence, they followed their former migration direction. Bimodality in orientation when exposed to the reversed magnetic field could be the result of a cue conflict, between magnetic and possibly celestial cues. For maintaining their migration direction toads use, at least partly, the geomagnetic field as a reference system.

  10. Toad heart utilizes exclusively slow skeletal muscle troponin T: an evolutionary adaptation with potential functional benefits.

    Feng, Han-Zhong; Chen, Xuequn; Hossain, M Moazzem; Jin, Jian-Ping

    2012-08-24

    The three isoforms of vertebrate troponin T (TnT) are normally expressed in a muscle type-specific manner. Here we report an exception that the cardiac muscle of toad (Bufo) expresses exclusively slow skeletal muscle TnT (ssTnT) together with cardiac forms of troponin I and myosin as determined using immunoblotting, cDNA cloning, and/or LC-MS/MS. Using RT-PCR and 3'- and 5'-rapid amplification of cDNA ends on toad cardiac mRNA, we cloned full-length cDNAs encoding two alternatively spliced variants of ssTnT. Expression of the cloned cDNAs in Escherichia coli confirmed that the toad cardiac muscle expresses solely ssTnT, predominantly the low molecular weight variant with the exon 5-encoded NH(2)-terminal segment spliced out. Functional studies were performed in ex vivo working toad hearts and compared with the frog (Rana) hearts. The results showed that toad hearts had higher contractile and relaxation velocities and were able to work against a significantly higher afterload than that of frog hearts. Therefore, the unique evolutionary adaptation of utilizing exclusively ssTnT in toad cardiac muscle corresponded to a fitness value from improving systolic function of the heart. The data demonstrated a physiological importance of the functional diversity of TnT isoforms. The structure-function relationship of TnT may be explored for the development of new treatment of heart failure. PMID:22778265

  11. Origin and genome evolution of polyploid green toads in Central Asia: evidence from microsatellite markers

    Betto-Colliard, C; Sermier, R; Litvinchuk, S; Perrin, N; Stöck, M

    2015-01-01

    Polyploidization, which is expected to trigger major genomic reorganizations, occurs much less commonly in animals than in plants, possibly because of constraints imposed by sex-determination systems. We investigated the origins and consequences of allopolyploidization in Palearctic green toads (Bufo viridis subgroup) from Central Asia, with three ploidy levels and different modes of genome transmission (sexual versus clonal), to (i) establish a topology for the reticulate phylogeny in a species-rich radiation involving several closely related lineages and (ii) explore processes of genomic reorganization that may follow polyploidization. Sibship analyses based on 30 cross-amplifying microsatellite markers substantiated the maternal origins and revealed the paternal origins and relationships of subgenomes in allopolyploids. Analyses of the synteny of linkage groups identified three markers affected by translocation events, which occurred only within the paternally inherited subgenomes of allopolyploid toads and exclusively affected the linkage group that determines sex in several diploid species of the green toad radiation. Recombination rates did not differ between diploid and polyploid toad species, and were overall much reduced in males, independent of linkage group and ploidy levels. Clonally transmitted subgenomes in allotriploid toads provided support for strong genetic drift, presumably resulting from recombination arrest. The Palearctic green toad radiation seems to offer unique opportunities to investigate the consequences of polyploidization and clonal transmission on the dynamics of genomes in vertebrates. PMID:25370211

  12. Carcinogenic effect of biscuits made of flour infested with Tribolium castaneum in Bufo regularis.

    el-Mofty, M M; Sakr, S A; Osman, S I; Toulan, B A

    1989-01-01

    Biscuits made of flour infested with Tribolium castaneum induced the formation of hepatocellular carcinomas (22%) when force-fed to toads (Bufo regularis) at a dose level of 200 mg/50 g 3 times a week. Maximal time of exposure and observation was 16 weeks. Some metastatic deposits from the primary liver tumours were found in the kidneys. Thus, the carcinogenic potency of the biscuits was almost the same as that of the flour previously reported by the authors indicating that the temperature of the oven in which the biscuits were baked did not alter the carcinogenicity of the infested flour. PMID:2915895

  13. Phospholipid transfer activities in toad oocytes and developing embryos

    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 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

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

    Luciana Sonne

    2008-09-01

    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 ao 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.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 intoxication 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.

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

    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.

  16. Vitamin A and its inhibitory effect as tested on Egyptian toads.

    Sadek, I A

    1981-01-01

    Neoplasms of the liver were induced in 18 cases out of 44 in the Egyptian toad, Bufo regularis, by injection with 20-methylcholanthrene. Dose level was 10 mg/50 g body weight once a week. However, the injection of the same dose level of this hydrocarbon together with vitamin A palmitate on the level of 20,000 IU/50 g body weight once a week was found to develop hepatomas in the liver in only 1 of 45 cases. Results of this study indicate that vitamin A palmitate inhibited the carcinogenic effect of 20-methylcholanthrene. PMID:7443172

  17. Rapid identification of primary constituents in parotoid gland secretions of the Australian cane toad using HPLC/MS-Q-TOF.

    Jing, Jing; Ren, Wei C; Li, Chun; Bose, Utpal; Parekh, Harendra S; Wei, Ming Q

    2013-06-01

    Toad parotoid gland secretion or toad venom has in recent years been increasingly shown to possess potentially beneficial pharmacological effects; this speculation has drawn much interest centred on elucidating the chemical basis of its multimodal effects. For this purpose, we explored the use of a rapid and accurate analysis method for systemic investigation of the parotoid gland chemistry, when extracted from Australian cane toads. Full-scan data of cane toad venom extract was acquired using high-performance liquid chromatography coupled with a hybrid quadrupole-time of flight mass spectrometry system (HPLC/MS-Q-TOF), with multiple ionization sources (ESI and APCI) in positive and negative mixed modes. By measuring the exact mass differences between the theoretical and measured mass of each assumed compound, we confirmed the presence of 12 key constituents. The present results demonstrate that the use of HPLC/MS-Q-TOF with multiple ionization sources delivers exemplary selectivity and sensitivity, allowing for the rapid and accurate identification of constituents within cane toad venom. This paves the way for this technique to be used in future routine screening of components within the genus Bufo and for key analytes too, then reliably assessed for any purported beneficial (clinic) properties. PMID:23319165

  18. Sublethal effects of endosulfan and diazinon pesticides on glutathione-S-transferase (GST) in various tissues of adult amphibians (Bufo regularis).

    Ezemonye, Lawrence; Tongo, Isioma

    2010-09-01

    Glutathione-S-transferase (GST) plays a key role in cellular detoxification of various xenobiotic chemical, especially pesticides. The study was carried out to assess the effects of the organochlorine pesticide, endosulfan and the organophosphate pesticide, diazinon on the activity of GST of different tissues in the African common toad, Bufo regularis. Toads were exposed for 28 days to varying levels of the pesticides: 0.01, 0.02, 0.03 and 0.04 microg L(-1) for the sublethal test. Activity of GST of toads exposed to the pesticides differentially increased significantly with increasing concentrations. The highest enhancement in GST activity was recorded in the liver followed by the brain, serum, GIT and lungs for both pesticide exposures. The differential increase in GST activity was tissue and pesticide specific. Liver GST increased up to 366% in endosulfan exposed toads and 393% in diazinon exposed toads in the highest concentration (0.04 microg L(-1)). Diazinon pesticide from this study proved to be more toxic than endosulfan pesticide. PMID:20609459

  19. Prostaglandins as mediators of acidification in the urinary bladder of Bufo marinus

    Experiments were performed to determine whether prostaglandins (PG) play a role in H+ and NH4+ excretion in the urinary bladder of Bufo marinus. Ten paired hemibladders from normal toads were mounted in chambers. One was control and the other hemibladder received PGE2 in the serosal medium (10(-5) M). H+ excretion was measured by change in pH in the mucosal fluid and reported in units of nmol (100 mg tissue)-1 (min)-1. NH4+ excretion was measured colorimetrically and reported in the same units. The control group H+ excretion was 8.4 +/- 1.67, while the experimental group was 16.3 +/- 2.64 (P less than 0.01). The NH4+ excretion in the experimental and control group was not significantly different. Bladders from toads in a 48-hr NH4+Cl acidosis (metabolic) did not demonstrate this response to PGE2 (P greater than 0.30). Toads were put in metabolic acidosis by gavaging with 10 ml of 120 mM NH4+Cl 3 x day for 2 days. In another experiment, we measured levels of PG in bladders from control (N) and animals placed in metabolic acidosis (MA). Bladders were removed from the respective toad, homogenized, extracted, and PG separated using high-pressure liquid chromatography and quantified against PG standards. The results are reported in ng (mg tissue)-1. PGE2 fraction in N was 1.09 +/- 0.14 and in MA was 3.21 +/- 0.63 (P less than 0.01). PGF1 alpha, F2 alpha and I2 were not significantly different in N and MA toads. Bladders were also removed from N and MA toads, and incubated in Ringer's solution containing [3H]arachidonic acid (0.2 microCi/ml) at 25 degrees C for 2 hr. Bladders were then extracted for PG and the extracts separated by thin layer chromatography. PG were identified using standards and autoradiography, scraped from plates, and counted in a scintillation detector. The results are reported in cpm/mg tissue x hr +/- SEM

  20. Assessment of pollution in road runoff using a Bufo viridis biological assay

    Road runoff is a major source of environmental pollution, significantly threatening nearby aquatic habitats. Chemical analyses indicate high pollutant concentrations in the road's 'first flush', but bioassays are more advantageous for addressing the cumulative effects of the numerous pollutants within the runoff. We used Bufo viridis embryos and larvae to assess the toxicity of road runoff from two major highways in Israel. We show, for the first time, that exposure to midseason runoff not only has an adverse effect on growth and development rates of B. viridis larvae but can also lead to increased rates of morphological deformations. Seasonal first flushes, despite having higher metal concentrations, did not adversely affect the toad larvae, apparently due to a counter effect of organic matter that potentially served as a supplementary energy resource. Road runoff can be a major cause for a qualitative decrease in the quality of aquatic habitats threatening amphibians in Israel. - Highway runoff has detrimental effects on the development of B. viridis larvae.

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

    Lawrence Ikechukwu Ezemonye

    2011-12-01

    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 (P<0.05 relative to controls. The decline was concentration- dependent as concentration of cadmium increased. The decline in hemoglobin and hematocrit in the experimental organism could be due to a decrease in the synthesis or release of erythrocytes into the circulation or an increase in the rate of erythrocyte destruction inflicted by cadmium toxicity. There was significant (P<0.05 elevation in total leuko- leukocyte count (TLC with increase in the concen- cyte concentration of cadmium. The increase in total leukocyte count observed in this study could be attributed to a stimulation of the immune system in response to tissue damage caused by cadmium toxicity. The study has shown that the exposure of the Bufo 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.

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

    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.

  3. Analgesic Effects of Toad Cake and Toad-cake-containing Herbal Drugs: Analgesic effects of toad cake

    Inoue Eiji; Shimizu Yasuharu; Masui Ryo; Usui Tomomi; Sudoh Keiichi

    2014-01-01

    Objectives: This study was conducted to clarify the analgesic effect of toad cake and toad-cake-containing herbal drugs. Methods: We counted the writhing response of mice after the intraperitoneal administration of acetic acid as a nociceptive pain model and the withdrawal response after the plantar surface stimulation of the hind paw induced by partial sciatic nerve ligation of the mice as a neuropathic pain model to investigate the analgesic effect of toad cake and toad-cake-containing h...

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

    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.

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

    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.

  6. Forelimb kinematics during hopping and landing in toads.

    Cox, S M; Gillis, Gary B

    2015-10-01

    Coordinated landing in a variety of animals involves the re-positioning of limbs prior to impact to safely decelerate the body. However, limb kinematics strategies for landing vary considerably among species. For example, human legs are increasingly flexed before impact as drop height increases, while turkeys increasingly extend their legs before impact with increasing drop height. In anurans, landing typically involves the use of the forelimbs to decelerate the body after impact. Few detailed, quantitative descriptions of anuran forelimb kinematics during jumping exist and it is not known whether they prepare for larger landing forces by changing forelimb kinematics. In this study, we used high-speed video of 51 hops from five cane toads (Bufo marinus) to test the hypothesis that forelimb kinematics change predictably with distance. We measured excursions of the elbow (flexion/extension) and humerus (protraction/retraction and elevation/depression) throughout every hop. The results indicate that elbow and humeral excursions leading up to impact increase significantly with hop length, but do so without any change in the rate of movement. Instead, because the animal is in the air longer during longer hops, near-constant velocity movements lead to the larger excursions. These larger excursions in elbow extension result in animals hitting the ground with more extended forelimbs in longer hops, which in turn allows animals to decelerate over a greater distance. PMID:26254325

  7. The complete mitochondrial genome of Bufo raddei.

    Zhang, Wenya; Zhang, Xingjie; Guo, Rui; Tang, Yue; Zhang, Yingmei

    2016-09-01

    The complete mitochondrial genome of Bufo raddei is carried out in the present research using Illumina Hiseq 2500. The mitogenome is 17 602 bp in length and contains 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and a D-loop region. The overall base composition of the H-strand is 29.15% for A, 26.09% for C, 15.16% for G, and 29.60% for T. The G + C content is 41.25%. Phylogenetic analyses of B. raddei and other 12 amphibian were carried out using Bayesian phylogenetic methods. The sequences of B. raddei were clustered in genus Bufo. PMID:26355835

  8. Comparison of isometric contractile properties in hindlimb extensor muscles of the frogs Rana pipiens and Bufo marinus: functional correlations with differences in hopping performance.

    Chadwell, Brad A; Hartwell, Hadley J; Peters, Susan E

    2002-03-01

    The leopard frog (Rana pipiens) is an excellent jumper that can reach high take-off velocities and accelerations. It is diurnal, using long, explosive jumps to capture prey and escape predators. The marine toad (Bufo marinus) is a cryptic, nocturnal toad, typically using short, slow hops, or sometimes walking, to patrol its feeding area. Typical of frogs with these different locomotor styles, Rana has relatively long hindlimbs and large (by mass) hindlimb extensor muscles compared to Bufo. We studied the isometric contractile properties of their extensor muscles and found differences that correlate with their different hopping performances. At the hip (semimembranosus, SM), knee (peroneus, Per) and ankle (plantaris longus, PL), we found that Rana's muscles tended to produce greater maximum isometric force relative to body mass, although the difference was significant only for PL. This suggests that differences in force capability at the ankle may be more important than at other joints to produce divergent hopping performances. Maximum isometric force scaled with body mass so that the smaller Rana has relatively larger muscles and force differences between species may reflect size differences only. In addition, Rana's muscles exhibited greater passive resistance to elongation, implying more elastic tissue is present, which may amplify force at take-off due to elastic recoil. Rana's muscles also achieved a higher percentage of maximum force at lower stimulus inputs (frequencies and durations) than in Bufo, perhaps amplifying the differences in force available for limb extension during natural stimulation. Twitch contraction and relaxation times tended to be faster in Rana, although variation was great, so that differences were significant only for Per. Fatigability also tended to be greater in Rana muscles, although, again, values reached significance in only one muscle (PL). Thus, in addition to biomechanical effects, differences in hopping performance may also be determined by diverse physiological properties of the muscles. PMID:11835367

  9. Anomalías oculares en híbridos Bufo paranecmis ? x Bufo arenarum ? (Anura: Bufonidae

    Rengel, Dora

    1994-01-01

    Full Text Available Los híbridos entre Bufo paracnemis x Bufo arenarum se encuadran en los llamados "híbridos vitales". Los resultados han evidenciado relevantes anomalías oculares que se manifiestan en un 90% de los casos. En algunas larvas falta el cristalino tanto en uno como en ambos ojos (20%; en otras larvas el cristalino se encuentra ubicado en posición opuesta al normal (25% o bien puede ocurrir que se forme un ojo normal y el otro de forma distinta (20%. El análisis histológico mostró anomalías en la zona retiniana, evidenciándose a partir de los estratos pigmentarios, repliegues y movimientos flexuosos (5%. También existen ojos replegados sobre sí mismos (5%. Las alteraciones más severas llevaron a procesos de anoftalmia (10%. En ocasiones (5% en lugar del ojo se evidencian grumos de pigmento. Se obtuvo un 10% con ojos normales. Los otros órganos presentan analogía con los de las larvas de Bufo paracnemis, inclusive la librea dorsal. The hybrids between Bufo paracnemis x Bufo arenarum are counted among tbe so called "vital hybrids". Our results have revealed relevant ocular anomalies in 90% of cases. In some larvae the lens is lacking in either one or both eyes (20%; in others the lens it is found in an opposite position to normal (25% or else one normal and one different eye is formed (20%. Histological analysis reveals anomalies in the retinal area, observing flexuous movements in the pigmentary strata (5%. Eyes folded over themselves were also observed (5%. The most severe alterations produced cases of anophtalmia (10%. On occasions (5%, groupings of pigments were found instead of the eyes. l0% of the larvae were normal. The other organs show analogies to those of the larvae of Bufo paracnemis, including the dorsal pattem.

  10. A New C23 Steroid from the Venom of Bufo bufo gargarizans.

    Luo, Shi-Lin; Tian, Hai-Yan; Liu, Jun-Shan; Wang, Ying; Ye, Wen-Cai

    2015-08-01

    A new C23 steroid, (3β,5β,14β)-methyl (3-hydroxy-14,15-epoxy-20-oxo-21-norcholan-24-oate) (1), together with four known ones (2-5), were isolated from the venom of Bufo bufo gargarizans. Their structures were elucidated on the basis of extensive spectroscopic analysis. The cytotoxicity of these compounds was also evaluated against human hepatocarcinoma HepG2 cells. Compound 3 showed significant cytotoxicity with an IC50 value of 16.8 +/- 0.7 μM. PMID:26434114

  11. Quelques caracteristiques biologiques de la reproduction du Crapaud commun (Bufo bufo L.) au Pays Basque

    VIGNES, J.C.

    2009-01-01

    Se analizan las características reproductoras del sapo común (Bufo bufo L.) a lo largo de 13 años (1993-2005) en una población del País Vasco. El periodo de reproducción comienza de finales de enero a mediados de febrero y finaliza en abril, en ocasiones a primero de mayo. Aproximadamente el 75% de las puestas se realiza en marzo. La sex-ratio de los animales capturados en el lugar de puesta (n = 7313) es netamente favorable a los machos (6,3:1), con variaciones anuales muy importantes, compr...

  12. Post-Messinian evolutionary relationships across the Sicilian channel: Mitochondrial and nuclear markers link a new green toad from Sicily to African relatives

    Lo Brutto Sabrina

    2008-02-01

    Full Text Available Abstract Background Little attention has been paid to the consequences of the last landbridge between Africa and Sicily on Mediterranean biogeography. Previous paleontological and scarce molecular data suggest possible faunal exchange later than the well-documented landbridge in the Messinian (5.3 My; however, a possible African origin of recent terrestrial Sicilian fauna has not been thoroughly tested with molecular methods. To gain insight into the phylogeography of the region, we examine two mitochondrial and two nuclear markers (one is a newly adapted intron marker in green toads (Bufo viridis subgroup across that sea barrier, the Strait of Sicily. Results Extensive sampling throughout the western Mediterranean and North Africa revealed a deep sister relationship between Sicilian (Bufo siculus n.sp. and African green toads (B. boulengeri on the mitochondrial and nuclear level. Divergence times estimated under a Bayesian-coalescence framework (mtDNA control region and 16S rRNA range from the Middle Pliocene (3.6 My to Pleistocene (0.16 My with an average (1.83 to 2.0 My around the Pliocene/Pleistocene boundary, suggesting possible land connections younger than the Messinian (5.3 My. We describe green toads from Sicily and some surrounding islands as a new endemic species (Bufo siculus. Bufo balearicus occurs on some western Mediterranean islands (Corsica, Sardinia, Mallorca, and Menorca and the Apennine Peninsula, and is well differentiated on the mitochondrial and nuclear level from B. siculus as well as from B. viridis (Laurenti, whose haplotype group reaches northeastern Italy, north of the Po River. Detection of Calabrian B. balearicus haplotypes in northeastern Sicily suggests recent invasion. Our data agree with paleogeographic and fossil data, which suggest long Plio-Pleistocene isolation of Sicily and episodic Pleistocene faunal exchange across the Strait of Messina. It remains unknown whether both species (B. balearicus, B. siculus occur in sympatry in northern Sicily. Conclusion Our findings on green toads give the first combined mitochondrial and nuclear sequence evidence for a phylogeographic connection across the Strait of Sicily in terrestrial vertebrates. These relationships may have implications for comparative phylogeographic research on other terrestrial animals co-occurring in North Africa and Sicily.

  13. Analgesic Effects of Toad Cake and Toad-cake-containing Herbal Drugs

    Inoue Eiji

    2014-03-01

    Full Text Available Objectives: This study was conducted to clarify the analgesic effect of toad cake and toad-cake-containing herbal drugs. Methods: We counted the writhing response of mice after the intraperitoneal administration of acetic acid as a nociceptive pain model and the withdrawal response after the plantar surface stimulation of the hind paw induced by partial sciatic nerve ligation of the mice as a neuropathic pain model to investigate the analgesic effect of toad cake and toad-cake-containing herbal drugs. A co-treatment study with serotonin biosynthesis inhibitory drug 4-chloro-DL-phenylalanine methyl ester hydrochloride (PCPA, the catecholamine biosynthesis inhibitory drug ?-methyl-DL-tyrosine methyl ester hydrochloride (AMPT or the opioid receptor antagonist naloxone hydrochloride was also conducted. Results: Analgesic effects in a mouse model of nociceptive pain and neuropathic pain were shown by oral administration of toad cake and toad-cake-containing herbal drugs. The effects of toad cake and toad-cake-containing herbal drugs disappeared upon co-treatment with PCPA, but not with AMPT or naloxone in the nociceptive pain model; the analgesic effect of toad-cake-containing herbal drugs also disappeared upon co-treatment with PCPA in the neuropathic pain model. Conclusion: Toad cake and toad-cake-containing herbal drugs have potential for the treatments of nociceptive pain and of neuropathic pain, such as post-herpetic neuralgia, trigeminal neuralgia, diabetic neuralgia, and postoperative or posttraumatic pain, by activation of the central serotonin nervous system.

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

    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 μg Cu/g dry mass. Aqueous concentrations of Cu as low as 10 μg/L significantly reduced survival to the free-swimming stage and no larvae reached metamorphosis at concentrations above 15 μg/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 μg Cu/g dry mass. -- Capsule: Southern toad aquatic survival is significantly reduced at 15 μg Cu/L with variation in survivorship across clutches and populations

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

    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

  16. Effects of season and temperature acclimation on electrocardiogram and heart rate of toads.

    Chapovetsky, Victoria; Katz, U

    2003-01-01

    Electrocardiogram (ECG) was recorded from unrestrained toads of two species, one resistant (Bufo viridis) and the other sensitive (B. regularis) to low temperatures. Although the temperature-sensitive species could not survive at temperatures below 7-8 degrees C, heart rate is linearly and similarly related to ambient temperature in the two species. In B. viridis, the cold resistant species, heart rate in winter was 25% lower than in summer, and the dependency of heart rate on temperature was reduced by 50% in toads acclimated to 10 degrees C in winter. It was not possible to disclose any effect of acclimation on heart rate in summer, due to the large variation in the recorded values. The QRS amplitude in the ECG was considerably reduced at low temperature only in B. viridis. It is concluded that differences in cardiac activity cannot account for the distinct difference in thermal relations of the two species, and that it should reside at other regulatory levels. PMID:12507610

  17. Diseases of frogs and toads

    Green, D.E.; Converse, K.A.

    2005-01-01

    This chapter presents information on infectious diseases of free-living frogs and toads that have completed metamorphosis. The diseases discussed in this chapter pertain principally to sub-adult and adult frogs and toads that are at least 60-90 days removed from completion of metamorphosis. The main emphasis of this chapter is the diseases found in amphibians of Canada and the United States. Diseases of recent metamorphs, larvae and amphibian eggs are presented in the chapters Diseases of Amphibian Eggs and Embryos and Diseases of Tadpoles. The smallest disease agents (viruses and bacteria) are presented first, followed by fungi, protozoa, helminths and ectoparasites. Diseases presented in this chapter are Ranaviral (iridovirus) infection Lucke frog herpesvirus (kidney cancer) Frog erythrocytic virus West Nile virus Red-leg disease (bacterial septicemia) Salmonellosis Chytrid fungal infection Basidiobolus fungi Dermosporidiosis Ichthyophoniasis Dermocystidium & Dermomycoides Myxozoa Ribeiroia flukes and Amphibian malformations Clinostomum metacercaria Aspects of each disease are presented to assist the biologist with recognition of diseases in the field. Hence, the major emphases for identification of diseases are the epizootiological aspects (host species, life stage, casualty numbers, etc) and gross findings ('lesions'). Descriptions of the microscopical, ultrastructural and cultural characteristics of each infectious agent were considered beyond the scope of this text. Detailed cultural and microscopical features of these disease agents are available in other reviews (Taylor et al., 2001; Green, 2001). Some diseases, while common in captive and zoo amphibians, are exceptionally rare in free-living frogs and toads, and therefore are omitted from this review. Among the diseases not presented are infections by chlamydia and mycobacteria, which occur principally in captive colonies of African clawed frogs (Xenopus, Hymenochirus, et al.) and northern leopard frogs (Rana pipiens). Other interesting diseases could have been presented, such as a wart-like virus infection of Japanese newts and a group of protistan parasites, referred to as Dermocystidium and Dermomycoides, in European frogs and toads. The reader is referred to Green (2001) for a review of these diseases. Amphibians have a rich diversity of helminthic parasites (Poynton and Whitaker, 2001). In general, most cestodes, trematodes and nematodes of amphibians are innocuous and not linked to specific clinical signs ('symptoms') or mortalities. An important major exception to this generalization is the trematode, Ribeiroia, which has been linked to numerous and bizarre malformations of frogs, toads and salamanders (Johnson et al., 1999, Johnson et al., 2001, Schotthoefer et al., 2003). Two genera of trematodal parasites are discussed in this chapter: Ribeiroia because they cause malformations and Clinostomum because they are large and produce visible lumps in the skin. For a review of amphibian helminths, the reader is referred to the text by Flynn (1973).

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

    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.

  19. Participation of nitric oxide in the nucleus isthmi in CO2-drive to breathing in toads

    Gargaglioni L.H.

    1999-01-01

    Full Text Available The nucleus isthmi (NI is a mesencephalic structure of the amphibian brain. It has been reported that NI plays an important role in integration of CO2 chemoreceptor information and glutamate is probably involved in this function. However, very little is known about the mechanisms involved. Recently, it has been shown that nitric oxide synthase (NOS is expressed in the brain of the frog. Thus the gas nitric oxide (NO may be involved in different functions in the brain of amphibians and may act as a neurotransmitter or neuromodulator. We tested the hypothesis that NO plays a role in CO2-drive to breathing, specifically in the NI comparing pulmonary ventilation, breathing frequency and tidal volume, after microinjecting 100 nmol/0.5 µl of L-NAME (a nonselective NO synthase inhibitor into the NI of toads (Bufo paracnemis exposed to normocapnia and hypercapnia. Control animals received microinjections of vehicle of the same volume. Under normocapnia no significant changes were observed between control and L-NAME-treated toads. Hypercapnia caused a significant (P<0.01 increase in ventilation only after intracerebral microinjection of L-NAME. Exposure to hypercapnia caused a significant increase in breathing frequency both in control and L-NAME-treated toads (P<0.01 for the control group and P<0.001 for the L-NAME group. The tidal volume of the L-NAME group tended to be higher than in the control group under hypercapnia, but the increase was not statistically significant. The data indicate that NO in the NI has an inhibitory effect only when the respiratory drive is high (hypercapnia, probably acting on tidal volume. The observations reported in the present investigation, together with other studies on the presence of NOS in amphibians, indicate a considerable degree of phylogenetic conservation of the NO pathway amongst vertebrates.

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

    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.

  1. Structural characterization of an Lyt-2/3 homolog expressed on Bufo regularis lymphocytes.

    Negm, H I; Mansour, M H; Saad, A H; Abdel Halim, R S

    1996-01-01

    Two alloantisera and a monoclonal antibody (mAb 53-6.7) of proven specificities to the murine Lyt-2/3 macromolecule labeled, in indirect immunofluorescent assays, a distinct lymphocyte population in the toad, Bufo regularis. Lyt-2/3 antigenic activities expressed by B. regularis lymphocytes have been solubilized and purified by mAb 53-6.7 affinity chromatography and found to be associated with a single 67 kDa macromolecule in SDS-PAGE. Upon reduction, this macromolecule resolved into 38 kDa, 34 kDa and 28 kDa subunits corresponding to the alpha, alpha' and beta subunits of the murine Lyt-2/3 complex. Comparisons based on the S delta Q index of differences in amino acid compositions of HPLC-purified alpha- and alpha'-subunits of the amphibian Lyt-2/3 molecule indicated a significant structural relatedness to their murine counterpart as well as to the human CD8 polypeptide. Our observations point to an early phylogenetic emergence of Lyt-2/3 as an important component of the T cell cytolytic apparatus during vertebrate evolution. PMID:8936043

  2. Sulfate transport in toad skin

    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...

  3. 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...

  4. Beta-adrenergic activation of solute coupled water uptake by toad skin epithelium results in near-isosmotic transport

    Nielsen, Robert; Larsen, Erik Hviid

    2007-01-01

    Transepithelial potential (V(T)), conductance (G(T)), and water flow (J(V)) were measured simultaneously with good time resolution (min) in isolated toad (Bufo bufo) skin epithelium with Ringer on both sides. Inside application of 5 microM isoproterenol resulted in the fast increase in G(T) from 1......-circuit current and J(V) with a [Na+] of the transported fluid of 130+/-24 mM ([Na+]Ringer's solution = 117.4 mM). Addition of bumetanide to the inside solution reduced J(V). Water was transported uphill and J(V) reversed at an excess outside osmotic concentration, deltaC(S,rev) = 28.9+/-3.9 mOsm, amiloride...... decreased deltaC(S,rev) to 7.5+/-1.5 mOsm. It is concluded that water uptake is accomplished by osmotic coupling in the lateral intercellular space (lis), and hypothesized that a small fraction of the Na+ flux pumped into lis is recirculated via basolateral NKCC transporters....

  5. Angel of human health: current research updates in toad medicine

    Yang, Qian; Zhou, Xuanxuan; Zhang, Meng; Bi, Linlin; Miao, Shan; Cao, Wei; Xie, Yanhua; Sun, Jiyuan; Tang, Haifeng; Li, Ying; Miao, Qing; Wang, Siwang

    2015-01-01

    There are currently 34 genera and 410 species of toads in the world. The medicinal parts of toads mainly include their venom, skin, and clothing. The toad’s venom and skin possess the same chemical components, mainly the toad venom lactone class, and their pharmacological effects primarily include the maintenance of strong heart, antitumor, antivirus, anti-infection, and analgesic effects. So far, the produces from the medicinal raw materials of the toad are widely used clinically around the ...

  6. Bufadienolides with cytotoxic activity from the skins of Bufo bufo gargarizans.

    Li, Bao-Jing; Tian, Hai-Yan; Zhang, Dong-Mei; Lei, Yu-He; Wang, Lei; Jiang, Ren-Wang; Ye, Wen-Cai

    2015-09-01

    Twelve new bufadienolides (1-12), along with fourteen known analogues (13-26) were isolated from the skins of Bufo bufo gargarizans Cantor. Their chemical structures were elucidated on the basis of NMR, HRESIMS and X-ray diffraction analysis. Compound 1 was an unusual bufadienolide with 3,19-epoxy moiety and A/B trans ring junction. Compounds 2-4 were rare bufadienolides possessing 10-H or 10-carboxyl units. All the isolated compounds were tested for their cytotoxic effects on HepG2, A549 and HeLa cells. Six new compounds (2, 3, 5, 6, 10 and 12) displayed significant anti-proliferative activities with IC50 values ranging from 0.049 to 1.856 μM. Arenobufagin (24) exhibited the most potent cytotoxic activity with IC50 value 0.011 μM. In addition, the present data provided more insight into the structure-activity relationships of bufadienolides. PMID:26022446

  7. Morphology of Bufo ictericus integument (Amphibia, Bufonidae).

    de Brito-Gitirana, L; Azevedo, R A

    2005-01-01

    Bufo ictericus integument was investigated by stereoscopic, low vacuum scanning electron microscopy, transmission electron microscopy and light microscopy. The studies revealed, that the dorsal integument surface is rougher than ventral. Three types of projections are visualized: larger rounded verrucae, smaller conical cornified tubercles, and conical short spines. Prominent verrucae are observed on the dorsal surface, being flatter on the ventral surface. The tubercles are visualized only on the dorsal surface. The verrucae are separated by grooves that may contribute spreading and retention of the glandular secretion upon the integument. The pattern of the epidermal grooves is also important for water distribution, protecting the animal against desiccation. The epidermis is composed of a stratified epithelium with intraepithelial blood vessels, where keratinocytes predominate, but flask cells, and Merkel cells also occur. In the spongious dermis, cutaneous glands are visualized. The compact dermis is a series of alternating layers of bundles of collagenous fibers, and between spongious and compact dermis there are basophilic areas that correspond to Eberth-Katschenko layer. The dorsal and the ventral surfaces of B. ictericus are morphologically distinct. The integument structure is related to the physiology of each surface and represents an adaptation to habitat, reflecting a lifestyle of the animal. PMID:15975802

  8. Involvement of Gα(olf)-expressing neurons in the vomeronasal system of Bufo japonicus.

    Hagino-Yamagishi, Kimiko; Nakazawa, Hideo

    2011-11-01

    Most terrestrial vertebrates possess anatomically distinct olfactory organs: the olfactory epithelium (OE) and the vomeronasal organ (VNO). In rodents, olfactory receptors coupled to Gα(olf) are expressed in the OE, whereas vomeronasal receptors type 1 (V1R) and vomeronasal receptors type 2 (V2R), coupled to Gα(i2) and Gα(o) , respectively, are expressed in the VNO. These receptors and G proteins are thought to play important roles in olfactory perception. However, we previously reported that only V2R and Gα(o) expression is detected in the Xenopus laevis VNO. As X. laevis spends its entire life in water, we considered that expression of limited types of chemosensory machinery in the VNO might be due to adaptation of the VNO to aquatic life. Thus, we analyzed the expression of G proteins in the VNO and the accessory olfactory bulb (AOB) of the adult Japanese toad, Bufo japonicus, because this species is well adapted to a terrestrial life. By using immunohistochemical analysis in combination with in situ hybridization and DiI labeling, we found that B. japonicus Gα(olf) and Gα(o) were expressed in the apical and middle-to-basal layer of the vomeronasal neuroepithelium, and that the axons of these Gα(olf) - and Gα(o) -expressing vomeronasal neurons projected to the rostral and caudal accessory olfactory bulb, respectively. These results strongly suggest that both the Gα(olf) - and Gα(o) -mediated signal transduction pathways function in the B. japonicus VNO. The expression of Gα(olf) in the B. japonicus VNO may correlate with the detection of airborne chemical cues and with a terrestrial life. PMID:21618228

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

    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.

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

    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 α-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 α-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.

  11. Helminth infracommunities of the maculated toad Amietophrynus regularis (Anura: Bufonidae) from Ismailia, Egypt.

    Ibrahim, Mohamed Moussa Ibrahim

    2008-10-16

    The objective of the present work was to study the helminth infracommunities of Amietophrynus (Bufo) regularis and the possible effects of intrinsic and extrinsic factors on infracommunity structure and on the infection parameters of each parasite species involved. A total of 129 A. regularis were collected from Ismailia, Egypt, over 3 seasons. Helminth infracommunities consisted of 8 helminth taxa (1 monogenean, 1 digenean, 1 cestode, 3 nematodes, and 2 acanthocephalans [1 adult and 1 cystacanth]). Aplectana macintoshii had the highest prevalence (82.94%), mean abundance (73.74), and mean intensity (88.91) and can be considered a core species. A. macintoshii dominated in 68.99% of the infracommunities, with a high Berger-Parker index value (0.9). Only 9 toads were uninfected; the remainder harbored between 1 and 7 helminth species and 1 to 632 ind. Mean species richness and abundance were 2.13 +/- 0.13 and 81.34 +/- 13.60, respectively, while evenness and diversity were 0.3 and 0.44, respectively. The results revealed that season, host sex, and age played significant roles in determining infracommunity species richness. The patterns of helminth infracommunity richness and diversity were similar to those previously observed in other amphibian hosts. This study indicated that the helminth community of A. regularis was depauperate. PMID:19062749

  12. Toxicity of cadmium administration to the toad and the treatment of its poisoning with EDTA.

    Hilmy, A M; el-Domaity, N; Daabees, A Y

    1986-01-01

    The effect of cadmium administration on female Bufo regularis was studied. The median lethal doses were 22, 18, 15 and 6.2 mg Cd2+/kg after 24, 48, 72 and 96 hr respectively. After a single intramuscular injection of 6.2 mg Cd2+/kg (representing 96-hr LD50), the results indicated that Cd2+ causes severe physiological abnormalities to this experimental animal. The serums alanine aminotransferase (AlAt), aspartate aminotransferase (AAt), alkaline phosphatase (AlP) and lactic dehydrogenase (LDH) were elevated while the calcium serum was not influenced by Cd2+ throughout the experimental period. On the other hand, phosphorus, total protein and total bilirubin were increased. EDTA treatment (0.2 mmole/kg) protected female toads from mortality up to 20 mg Cd2+/kg. It overcame the physiological alterations that were caused by the Cd2+ injection. This may be due to the fact that Cd2+ is bound to EDTA in a strong complex which is readily excreted via the kidneys. PMID:2877799

  13. Toad poisoning in three dogs: case reports

    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.

  14. JUVENILE WESTERN TOADS, BUFO BOREAS, AVOID CHEMICAL CUES OF SNAKES FED JUVENILE, BUT NOT LARVAL, CONSPECIFICS. (U915529)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  15. Wyoming toad, Bufo hemiophrys baxteri, habitat use and hibernaculum research project with the use of telemetry : Annual report

    US Fish and Wildlife Service, Department of the Interior — This annual report is on a two year study, started in 1998, to evaluate the daily and seasonal habitat use to determine the location of the hibemaculum of the...

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

    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].

  17. Toads on Lava: Spatial Ecology and Habitat Use of Invasive Cane Toads (Rhinella marina) in Hawai’i

    Ward-Fear, Georgia; Greenlees, Matthew J.; Shine, Richard

    2016-01-01

    Most ecological research on cane toads (Rhinella marina) has focused on invasive populations in Australia, ignoring other areas where toads have been introduced. We radio-tracked and spool-tracked 40 toads, from four populations on the island of Hawai’i. Toads moved extensively at night (mean 116 m, from spool-tracking) but returned to the same or a nearby retreat-site each day (from radio-tracking, mean distance between successive retreat sites 11 m; 0 m for 70% of records). Males followed straighter paths during nocturnal movements than did females. Because moist sites are scarce on the highly porous lava substrate, Hawai’ian toads depend on anthropogenic disturbance for shelter (e.g. beneath buildings), foraging (e.g. suburban lawns, golf courses) and breeding (artificial ponds). Foraging sites are further concentrated by a scarcity of flying insects (negating artificial lights as prey-attractors). Habitat use of toads shifted with time (at night, toads selected areas with less bare ground, canopy, understory and leaf-litter), and differed between sexes (females foraged in areas of bare ground with dense understory vegetation). Cane toads in Hawai’i thrive in scattered moist patches within a severely arid matrix, despite a scarcity of flying insects, testifying to the species’ ability to exploit anthropogenic disturbance. PMID:27027738

  18. Further Hopping with Toads and Frogs

    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.

  19. Interaction between Pax6 and its novel mutant in Bufo raddei Strauch

    Ju, Furong; Zhao, Yongqing; Zhao, Yuanlin; Wang, Ying; Wen, Fan; Ye, Lin

    2011-01-01

    Purpose Exploration of the relationship between a novel paired box 6 (Pax6) mutant and Pax6 in Bufo raddei Strauch. Methods RT–PCR, yeast 2-hybrid system, and co-immunoprecipitation were used to analyze the Pax6 protein and its mutant during embryonic eye development in Bufo raddei Strauch. Results We have cloned the Pax6 ORF sequence from Bufo raddei Strauch. Here we report the cloning of a novel Pax6 homolog of Bufo raddei Strauch named Pax6 variant. Comparing the 2 genes, the homolog of ORF nucleotide sequence is more than 99% in Bufo raddei Strauch; only the proline-serine-threonine(PST)-rich transaction domain differs. The deduced amino acid sequences of PST region are 53.1% identical. An interaction was found between Pax6 and Pax6 variant via yeast 2-hybrid system; with further study, we found that they interacted in vivo via co-immunopricipitation. Conclusions A Pax6 mutant was first found in Bufo raddei Strauch. Interaction between Pax6 and Pax6 variant may play a critical role during eye development in Bufo raddei Strauch. This suggests that expression of Pax6 variant may play a role and appears to be a necessity in eye development, but that Pax6 itself is still pivotal in eye development. PMID:22065923

  20. Biogeographic patterns of Colombian frogs and toads

    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

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

    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.

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

    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.

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

    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.

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

    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.

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

    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.

  6. WEAKLY SYNCHRYRONIZED SUBPOPULATION DYNAMICS IN WISCONSIN FROGS AND TOADS

    Spatial synchrony in population dynamics is a topic of increasing interest in basic and applied ecology. We used data from 18 years of frog and toad calling surveys conducted throughout Wisconsin to determine the level of intraspecific synchrony among survey sites, and the relat...

  7. Clinical and electrocardiographic evaluation during experimental toad poisoning in dogs

    AC Camplesi

    2010-01-01

    Full Text Available Accidents involving toad poisoning are frequent and dogs are the most common victims; they become poisoned by biting or ingesting a toad. When released in the organism, the venom is absorbed by both the oral mucosa and the digestive tract, initiating its toxic action. The aim of this work was to evaluate the clinical and electrocardiographic aspects of dogs subjected to experimental toad poisoning, as well as their response to treatment with propranolol. Twenty dogs were divided into two groups, a control group (n = 5 and a poisoned group (n = 15. After general anesthesia, the control group received a placebo, while the poisoned group received a venom aliquot through an orogastric tube. Results were tested through multivariate analysis (p < 0.05. The animals in the poisoned group had gastrointestinal symptoms including emesis, intense salivation, hyperemic or congested oral mucosa and pasty diarrhea. Non-responsive mydriasis, nystagmus, depression, stupor, tachypnea, opisthotonus and ataxia were also manifested by 100% of the poisoned animals. Affected dogs had an increase in blood pressure, statistically significant throughout study. Five poisoned animals developed ventricular tachycardia and were treated with propranolol (0.5 mg/kg IV. All propranolol-treated animals returned to normal sinus rhythm, which evidences the efficacy of this drug to treat ventricular arrhythmias caused by toad venom.

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

    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

  9. Life-threatening episode after ingestion of toad eggs: a case report with literature review

    Kuo, Hung-Yi; Hsu, Chin-Wang; Chen, Jiann-Hwa; Wu, Yung-Lung; Shen, Ying-Sheng

    2009-01-01

    It is known that the toad possesses several toxic substances in the skin and parotid glands. In the past, toad-venom poisoning has been reported from ingestion of toad soup, Kyushin and aphrodisiac pills, but poisoning from toad eggs is observed for the first time. The case of a healthy female who had previously eaten toad soup twice without any discomfort is reported. She developed gastrointestinal symptoms and life-threatening cardiac rhythm after ingestion of toad eggs. A transvenous temporary pacemaker was used promptly to prevent from lethal bradyarrhythmia. Hyperkalaemia was managed with insulin, glucose water and sodium bicarbonate. A digoxin-specific Fab fragment was administered to this young woman 4 h subsequent to her admission. PMID:21686394

  10. The identity of the South African toad Sclerophrys capensis Tschudi, 1838 (Amphibia, Anura)

    Ohler, Annemarie; Dubois, Alain

    2016-01-01

    The toad species Sclerophrys capensis Tschudi, 1838 was erected for a single specimen from South Africa which has never been properly studied and allocated to a known species. A morphometrical and morphological analysis of this specimen and its comparison with 75 toad specimens referred to five South African toad species allowed to allocate this specimen to the species currently known as Amietophrynus rangeri. In consequence, the nomen Sclerophrys must replace Amietophrynus as the valid nomen...

  11. Electrical responses of rods in the retina of Bufo marinus

    Cervetto, L.; Pasino, E.; Torre, V.

    1977-01-01

    1. Intracellular responses to flashes and steps of light have been recorded from the outer segment and the cell body of rods in the retina of the Bufo marinus. The identification of the origin of recorded responses has been confirmed by intracellular marking. 2. Responses to flashes delivered in darkness or superimposed on a background were analysed. Responses recorded from outer segments conform to the principle of `spectral univariance'. The shape of the response is not affected by enlarging the spot diameter from 150 to 1000 ?m. 3. The membrane potential measured in darkness at the outer segments varied from -15 to -25 mV. Injection of steady hyperpolarizing currents increases the size of the response to light; depolarizing currents reduce the response. The mean value of the input resistance is 97 ± 30 M? in darkness and increases by 20-30% during illumination. 4. The responses obtained from the cell body of rods have the same shape, time course and spectral sensitivity of those recorded at the outer segment. Injection of steady current at the cell body produces different effects than at the outer segment: hyperpolarizing currents reduce the amplitude of the response to light; depolarizing currents increase the response. 5. The experimental data are fitted according to a model similar to that used to describe the responses of turtle cones (Baylor & Hodgkin, 1974; Baylor, Hodgkin & Lamb, 1974a, b). 6. The model reproduces the electrical responses of the rod outer segment to a variety of stimuli: (a) brief flashes and steps of light in dark adapted conditions; (b) bright flashes superimposed on background illuminations; (c) pairs of flashes delivered at different time intervals. Responses to hyperpolarizing steps of current are also reproduced by the model. ImagesABCD PMID:406383

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

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

    Franco Zanghellini

    2006-11-01

    Full Text Available 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.

  14. Tissue kinetics, ion transport, and recruitment of mitochondria-rich cells in the skin of the toad (Bufo bufo) in response to exposure to distilled water

    Budtz, Poul Egede; Christoffersen, Betina C.; Johansen, Jesper S.; Spies, Ingrid B.M.; Willumsen, Niels J.

    1995-01-01

    Mitochondria-rich cells (MRC) of the amphibian epidermis are responsible for active chloride uptake at low external salinity, and new MRCs are recruited in response to exposure to distilled (deionized) water. The time-course of this recruitment, the tissue kinetics and ion transport have been...... decreased ICl and H+ flux per MRC, and by the increased proportion of MRCs unstained by Ag or MB. Full Cl- (but not H+) transport capacity, was restored at day-7. We conclude that increased DMRC following exposure to low external Cl-, rather than being due to an increased Kb, is the combined effect of a...

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

    Franco Zanghellini; Radames Bionda; Fabio Casale; 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. Travelling waves for the cane toads equation with bounded traits

    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)

  17. Vascular aspects of water uptake mechanisms in the toad skin: perfusion, diffusion, confusion

    Willumsen, Niels; Viborg, Arne L; Hillyard, Stanley D

    2007-01-01

    declined in parallel with BCF. Water absorption measured during the initial rehydration period did not correlate with BCF and hydrated toads injected with AVT increased water absorption without an increase in BCF indicating the lack of an obligate relation between blood flow and water absorption......Blood cell flow (BCF) in the water absorbing "seat patch" region of toad skin was measured with laser Doppler flow cytometry. BCF of dehydrated toads increased by a factor of 6-8 when water contact was made and declined gradually as toads rehydrated. Water absorption was initially stimulated and....... Aquaporins 1-3 were characterized by RT-PCR analysis of seat patch skin. AQP 1 was localized in the endothelium of subepidermal capillaries and serves as a pathway for water absorption in series with the apical and basolateral membranes of the epithelium. Dehydrated toads rehydrated more rapidly from dilute...

  18. Effects of ultraviolet radiation on boreal toads in Colorado

    Corn, P.S.

    1998-01-01

    Field exposures of Bufo boreas embryos to fractions of ambient UV-B radiation at two sites in Rocky Mountain National Park, Colorado, USA, were conducted to evaluate UV-B as a possible cause of recent severe declines of this species. There were no differences in hatching success of B. boreas embryos exposed to 0-100% of ambient UV-B radiation at either study site, results that are different from those of recent studies in Oregon that found increased mortality of B. boreas embryos exposed to ambient UV-B. The reasons for these differing results are not apparent, and several possible explanations exist, including differences in experimental design, presence or absence of a pathogenic fungus, and geographic genetic variation. Bufo boreas embryos were probably not receiving higher doses of UV-B radiation during the experiments in Oregon compared to the experiments in this study. Results of this study do not support UV-B radiation alone as the cause of the decline of B. boreas during the past 20 yr in the southern Rocky Mountains, but UV-B cannot be dismissed because of the contradictory results from other studies.

  19. Regenerative abnormalities in hind limbs of bufo regularis induced by repeated amputations: I. Early larval stages

    Abdel Karim, Ahmed E. [???? ????? ??? ??????

    1993-01-01

    The regenerative response of the hind limbs of early larval stages: 52, 53, 54 and 55 of Bufo regularis was studied following repeated amputations at the ankle level. The pattern of morphogenesis as well as skeletal configuration of the regenerates showed increasing degrees of abnormality, with a gradual reduction in the number of toes or phalanges, shortening of toes or complete cessation of regeneration, as the larvae grow older and the number of amputations increases. Reamputations at the ...

  20. Adrenocortical function in cane toads from different environments.

    Hernández, Sandra E; Sernia, Conrad; Bradley, Adrian J

    2016-05-01

    The adrenocortical function of cane toads (Rhinella marina) exposed to different experimental procedures, as well as captured from different environments, was assessed by challenging the hypothalamic-pituitary-adrenal (HPA) axis. It was found that restriction stress as well as cannulation increased plasma corticosterone (B) levels for up to 12h. A single dose of dexamethasone (DEX 2mg/kg) significantly reduced B levels demonstrating its potential for use in the evaluation of the HPA axis in amphibia. We also demonstrate that 0.05IU/g BW (im) of synthetic adrenocorticotropic hormone (ACTH) significantly increased plasma B levels in cane toads. Changes in size area of the cortical cells were positively associated with total levels of B after ACTH administration. We also found differences in adrenal activity between populations. This was assessed by a DEX-ACTH test. The animals captured from the field and maintained in captivity for one year at the animal house (AH) present the highest levels of total and free B after ACTH administration. We also found that animals from the front line of dispersion in Western Australia (WA) present the weakest adrenal response to a DEX-ACTH test. The animals categorized as long established in Queensland Australia (QL), and native in Mexico (MX), do not shown a marked difference in the HPA activity. Finally we found that in response to ACTH administration, females reach significantly higher levels of plasma B than males. For the first time the adrenocortical response in cane toads exposed to different experimental procedures, as well as from different populations was assessed systematically. PMID:26877241

  1. All-optical pseudorandom bit sequences generator based on TOADs

    Sun, Zhenchao; Wang, Zhi; Wu, Chongqing; Wang, Fu; Li, Qiang

    2016-03-01

    A scheme for all-optical pseudorandom bit sequences (PRBS) generator is demonstrated with optical logic gate 'XNOR' and all-optical wavelength converter based on cascaded Tera-Hertz Optical Asymmetric Demultiplexer (TOADs). Its feasibility is verified by generation of return-to-zero on-off keying (RZ-OOK) 263-1 PRBS at the speed of 1 Gb/s with 10% duty radio. The high randomness of ultra-long cycle PRBS is validated by successfully passing the standard benchmark test.

  2. The identity of the South African toad Sclerophrys capensis Tschudi, 1838 (Amphibia, Anura).

    Ohler, Annemarie; Dubois, Alain

    2016-01-01

    The toad species Sclerophrys capensis Tschudi, 1838 was erected for a single specimen from South Africa which has never been properly studied and allocated to a known species. A morphometrical and morphological analysis of this specimen and its comparison with 75 toad specimens referred to five South African toad species allowed to allocate this specimen to the species currently known as Amietophrynus rangeri. In consequence, the nomen Sclerophrys must replace Amietophrynus as the valid nomen of the genus, and capensis as the valid nomen of the species. This work stresses the usefulness of natural history collections for solving taxonomic and nomenclatural problems. PMID:26788431

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

    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.

  4. Pre-landing wrist muscle activity in hopping toads.

    Ekstrom, Laura J; Gillis, Gary B

    2015-08-01

    Coordinated landing requires preparation. Muscles in the limbs important for decelerating the body should be activated prior to impact so that joints may be stiffened and limbs stabilized during landing. Moreover, because landings vary in impact force and timing, muscle recruitment patterns should be modulated accordingly. In toads, which land using their forelimbs, previous work has demonstrated such modulation in muscles acting at the elbow, but not at the shoulder. In this study, we used electromyography and high-speed video to test the hypothesis that antagonistic muscles acting at the wrists of toads are activated in advance of impact, and that these activation patterns are tuned to the timing and force of impact. We recorded from two wrist extensors: extensor carpi ulnaris (ECU) and extensor digitorum communis longus (EDCL), and two wrist flexors: flexor carpi ulnaris (FCU) and palmaris longus (PL). Each muscle was recorded in 4-5 animals (?15 hops per animal). In all muscles, activation intensity was consistently greatest shortly before impact, suggesting the importance of these muscles during landing. Pre-landing recruitment intensity regularly increased with aerial phase duration (i.e. hop distance) in all muscles except PL. In addition, onset timing in both wrist flexors was also modulated with hop distance, with later onset times being associated with longer hops. Thus, activation patterns in major flexors and extensors of the wrist are tuned to hop distance with respect to recruitment intensity, onset timing or both. PMID:26026036

  5. B-carotene Lock the Effect of Acrylamide on Liver in the Egyptian Toad

    I. A. Sadek

    1999-01-01

    Full Text Available Several studies on the harmful effects of chemical pollutants have had an increasing influence on public cancer policy. It has been shown that acrylamide, which is widely used in the synthesis of variety of polymers, induced liver tumor in the Egyptian toad (9 cases out of 50 cases. The liver tumor was diagnosed as hepatocellular carcinoma. In contrast toads treated with acrylamide and B-carotene (3 hr. prior to the carcinogen completely blocked the hepatocarcinogenesis in toads. However B-carotene was less effective when administered 3hr, after the carcinogen (acrylamide in 7 out of 50 cases. It is concluded that B-carotene has an inhibitory effect on hepatocarcinogenesis in toads during initiation.

  6. Towed Optical Assessment Device (TOAD) Data to Support Benthic Habitat Mapping since 2001

    National Oceanic and Atmospheric Administration, Department of Commerce — Optical validation data were collected using a Tethered Optical Assessment Device (TOAD), an underwater sled equipped with an underwater digital video camera and...

  7. Ascorbic acid and its effect on the skin of Bufo regularis.

    Sadek, I A; Abdelmegid, N

    1982-01-01

    Skin papillomas were observed in the majority of toads when painted with 1 mg of 7,12-dimethyl-benz (alpha) anthracene (DMBA) dialy for 8 weeks. Animals injected with 10 mg/kg/day of ascorbic acid into the dorsal lymph sac showed tumor inhibition when painted with the same dose level of DMBA for 8 weeks. Tumor regression occurred in those animals receiving 10 mg/kg/day of ascorbic acid for 8 weeks. PMID:6813785

  8. Exposure and post-exposure effects of endosulfan on Bufo bufo tadpoles: morpho-histological and ultrastructural study on epidermis and iNOS localization.

    Bernabò, Ilaria; Guardia, Antonello; La Russa, Daniele; Madeo, Giuseppe; Tripepi, Sandro; Brunelli, Elvira

    2013-10-15

    Endosulfan is a persistent organic pollutant (POP) that has lethal and sublethal effects on non-target organisms, including amphibians. In a laboratory study, we investigated direct and post-exposure effects of endosulfan on Bufo bufo tadpoles. For this purpose we exposed the tadpoles to a single short-term contamination event (96 h) at an environmentally-realistic concentration (200 ?g endosulfan/L). This was followed by a recovery period of 10 days when the experimental animals were kept in pesticide-free water. The endpoints were assessed in terms of mortality, incidence of deformity, effects on behavior, and the morpho-functional features of the epidermis. We found that a short-term exposure to the tested concentration of endosulfan did not cause mortality but induced severe sublethal effects, such as hyperactivity, convulsions, and axis malformations. Following relocation to a pesticide-free environment, we noted two types of response within the experimental sample, in terms of morphological and behavioral traits. Moreover, by using both ultrastructural and a morpho-functional approach, we found that a short-term exposure to endosulfan negatively affected the amphibian epidermis. We also observed several histo-pathological alterations: increased mucous secretion, an increase in intercellular spaces and extensive cell degeneration, together with the induction of an inducible isoform of nitric oxide synthase (iNOS). Following the post-exposure period, we found large areas of epidermis in which degeneration phenomena were moderate or absent, as well as a further increase in iNOS immunoreactivity. Thus, after 10 days in a free-pesticide environment, the larval epidermis was able to partially replace elements that had been compromised due to a physiological and/or a pathological response to the pesticide. These results highlight the need for both exposure and post-exposure experiments, when attempting to assess pollutant effects. PMID:24036433

  9. Batrachochytrium dendrobatidis detected in Kihansi spray toads at a captive breeding facility (Kihansi, Tanzania).

    Makange, Mariam; Kulaya, Neema; Biseko, Emiliana; Kalenga, Parson; Mutagwaba, Severinus; Misinzo, Gerald

    2014-09-30

    The chytrid fungus Batrachochytrium dendrobatidis (Bd) is the aetiological agent of amphibian chytridiomycosis, a disease associated with global amphibian population declines. In November 2012, mass mortalities of Kihansi spray toads Nectophrynoides asperginis were observed at the Kihansi captive breeding facility, located in the Udzungwa Mountains, Tanzania. Mortalities increased rapidly, and dead toads showed typical clinical signs of chytridiomycosis, including reddening of the skin that was especially evident on the toe pads. Treatment of toads with itraconazole rapidly reduced mortalities. Dead toads (n = 49) were collected and used to perform Bd-specific polymerase chain reaction and subsequent nucleotide sequencing. All toads collected at the facility were positive for Bd. The obtained Bd 5.8S rRNA gene and flanking internal transcribed spacer regions (ITS1 and ITS2) were not 100% identical to any other Bd sequences in GenBank, but closely resembled isolates from Ecuador, Japan, USA, Brazil, Korea, and South Africa. To our knowledge, this is the first study reporting molecular characteristics of Bd isolated from the Udzungwa Mountains. Strict biosecurity measures at the breeding facility and in Kihansi spray wetlands where toads have been reintroduced have been implemented. Further studies on Bd epidemiology in the Udzungwa Mountains are recommended in order to understand its origin, prevalence, and molecular characteristics in wild amphibian populations. This will be important for conservation of several endemic amphibian species in the Udzungwa Mountains, which are part of the Eastern Arc Mountains, a global biodiversity hotspot. PMID:25266903

  10. CEPF Western Ghats Special Series: Description of tadpole stages of the Malabar Tree Toad Pedostibes tuberculosis Gunther, 1875 (Anura: Bufonidae

    K.P. Dinesh

    2014-10-01

    Full Text Available Pedostibes tuberculosus, the Malabar tree toad, was described 137 years ago from the Malabar region (now the coastal parts of Kerala of the Western Ghats. Since the description of this arboreal toad, not much information is available on the natural history, breeding habits and life cycle except for its description, range of distribution and advertisement call details. In the present account, the tadpole stages of this toad from Gosner tadpole Stage 21 to 45 are presented and the phytotelmatic mode of life of this toad has been confirmed by locating the tadpoles within the Ochlandra reed culm.

  11. 76 FR 70479 - Draft Environmental Assessment and Safe Harbor Agreement for the Houston Toad Within Nine Texas...

    2011-11-14

    ... successful toadlet survival; (6) creation of new breeding ponds; and (7) headstarting and/or reintroduction...; (4) increase Houston toad population numbers through headstarting and reintroduction; and...

  12. The Effects of the Toxic Cyanobacterium Limnothrix (Strain AC0243) on Bufo marinus Larvae

    Daniels, Olivia; Fabbro, Larelle; Makiela, Sandrine

    2014-01-01

    Limnothrix (strain AC0243) is a cyanobacterium, which has only recently been identified as toxin producing. Under laboratory conditions, Bufo marinus larvae were exposed to 100,000 cells mL?1 of Limnothrix (strain AC0243) live cultures for seven days. Histological examinations were conducted post mortem and revealed damage to the notochord, eyes, brain, liver, kidney, pancreas, gastrointestinal tract, and heart. The histopathological results highlight the toxicological impact of this strain, particularly during developmental stages. Toxicological similarities to ?-N-Methylamino-l-alanine are discussed. PMID:24662524

  13. Photoperiod and salinity effects on survival and some blood parameters in female Bufo regularis

    Hagras, Ahmed E. E.

    1986-01-01

    This study, investigates the effect of different salinities injected (30, 70 and 100 % sea water) and photoperiods (L:D/8:16,L:D/12:12 and L: D / 16 : 8 ) on female Bufo regularis (1) survival rate, (2 ) oxygen and carbon dioxide partial pressure, and (3) sodium and potassium contents. Undiluted sea water lowered the survival rate. while the highest survival rate occured at L: D / 16 : 8 combined with 30 % SW. PO, was lower in all experimental groups than in the controls. PO, tension was high...

  14. The Effects of the Toxic Cyanobacterium Limnothrix (Strain AC0243 on Bufo marinus Larvae

    Olivia Daniels

    2014-03-01

    Full Text Available Limnothrix (strain AC0243 is a cyanobacterium, which has only recently been identified as toxin producing. Under laboratory conditions, Bufo marinus larvae were exposed to 100,000 cells mL−1 of Limnothrix (strain AC0243 live cultures for seven days. Histological examinations were conducted post mortem and revealed damage to the notochord, eyes, brain, liver, kidney, pancreas, gastrointestinal tract, and heart. The histopathological results highlight the toxicological impact of this strain, particularly during developmental stages. Toxicological similarities to β-N-Methylamino-L-alanine are discussed.

  15. The All Optical New Universal Gate Using TOAD

    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.

  16. Inhibition by vitamin A of cyst formation in Nyctotheroides puytoraci induced by injecting its host Bufo regularis with 20-methylcholanthrene.

    Sadek, I A

    1980-08-01

    20-Methylcholanthrene induced cyst formation in Nyctotheroides puytoraci when injected into its host Bufo regularis. Presumably this hydrocarbon or its metabolites reaches the parasites in the recta of treated host animals and induces encystment. However, injection B. regularis with 0.5 mg of 20-methylcholanthrene + vitamin A palmitate (5,000 IU) inhibited the hydrocarbon-induced encystment of the parasites. PMID:6778995

  17. Spontaneous and LH-induced maturation in Bufo arenarum oocytes: importance of gap junctions.

    Toranzo, G Sánchez; Oterino, J; Zelarayán, L; Bonilla, F; Bühler, M I

    2007-02-01

    It has been demonstrated in Bufo arenarum that fully grown oocytes are capable of meiotic resumption in the absence of a hormonal stimulus if they are deprived of their follicular envelopes. This event, called spontaneous maturation, only takes place in oocytes collected during the reproductive period, which have a metabolically mature cytoplasm. In Bufo arenarum, progesterone acts on the oocyte surface and causes modifications in the activities of important enzymes, such as a decrease in the activity of adenylate cyclase (AC) and the activation of phospholipase C (PLC). PLC activation leads to the formation of diacylglycerol (DAG) and inositol triphosphate (IP(3)), second messengers that activate protein kinase C (PKC) and cause an increase in intracellular Ca(2+). Recent data obtained from Bufo arenarum show that progesterone-induced maturation causes significant modifications in the level and composition of neutral lipids and phospholipids of whole fully grown ovarian oocytes and of enriched fractions in the plasma membrane. In amphibians, the luteinizing hormone (LH) is responsible for meiosis resumption through the induction of progesterone production by follicular cells. The aim of this work was to study the importance of gap junctions in the spontaneous and LH-induced maturation in Bufo arenarum oocytes. During the reproductive period, Bufo arenarum oocytes are capable of undergoing spontaneous maturation in a similar way to mammalian oocytes while, during the non-reproductive period, they exhibit the behaviour that is characteristic of amphibian oocytes, requiring progesterone stimulation for meiotic resumption (incapable oocytes). This different ability to mature spontaneously is coincident with differences in the amount and composition of the phospholipids in the oocyte membranes. Capable oocytes exhibit in their membranes higher quantities of phospholipids than incapable oocytes, especially of PC and PI, which are precursors of second messengers such as DAG and IP(3). The uncoupling of the gap junctions with 1-octanol or halothane fails to induce maturation in follicles from the non-reproductive period, whose oocytes are incapable of maturing spontaneously. However, if the treatment is performed during the reproductive period, with oocytes capable of undergoing spontaneous maturation, meiosis resumption occurs in high percentages, similar to those obtained by manual defolliculation. Interestingly, results show that LH is capable of inducing GVBD in both incapable oocytes and in oocytes capable of maturing spontaneously as long as follicle cells are present, which would imply the need for a communication pathway between the oocyte and the follicle cells. This possibility was analysed by combining LH treatment with uncoupling agents such as 1-octanol or halothane. Results show that maturation induction with LH requires a cell-cell coupling, as the uncoupling of the gap junctions decreases GVBD percentages. Experiments with LH in the presence of heparin, BAPTA/AM and theophylline suggest that the hormone could induce GVBD by means of the passage of IP(3) or Ca(2+) through the gap junctions, which would increase the Ca(2+) level in the oocyte cytoplasm and activate phosphodiesterase (PDE), thus contributing to the decrease in cAMP levels and allowing meiosis resumption. PMID:17391547

  18. Can we control the invasive cane toad using chemicals that have evolved under intraspecific competition?

    Clarke, Gregory S; Crossland, Michael R; Shine, Richard

    2016-03-01

    Many invasive species experience intense intraspecific competition, because they are abundant in anthropogenically disturbed habitats where few native species persist. Species-specific competitive mechanisms that evolve in this context may offer novel, highly targeted means to control invasive taxa. We conducted laboratory experiments to evaluate the feasibility of this method of control, based on waterborne cues that are produced by tadpoles of the cane toad (Rhinella marina) to suppress the development of conspecific embryos. Our trials examined the nature and species-specificity of the effect, the robustness of the cue to freezing and storage, and the amounts required to suppress toad embryos. Our results were encouraging. The cue appears to be chemical rather than a biological organism, and may well be species-specific; the four species of native anurans that we tested were not influenced by toad larval cues. The cue retains its effectiveness after being frozen, but not after being dried, or after 7 d in water. It is effective at very low concentrations (the amount produced by three tadpoles within 750 L of water). Overall, the cane toad's suppressor pheromone may offer an effective new way to control invasive toads. PMID:27209788

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

    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.

  20. Radio-iodination of plasma membranes of toad bladder epithelium

    The present report describes yhigh yield enzymatic radio-iodination of the apical and basal-lateral plasma membranes of toad bladder epithelium with 125I-Na, by a procedure that does not breach the functional integrity of the epithelium, as assessed by the basal and vasopressin-sensitive short-circuit current (SCC). Iodination of basal-lateral plasma membranes, at a yield comparable to that obtained with apical labeling, was attained after about 30 min of exposure of the intact bladder to the labelling solutions. Approximately 25% of the basal-lateral labeling was lost when the epithelial cells were harvested after collagenase treatment, implying that some iodination of the basement membrane had taken place. Less than 10% of iodination of the apical or basal-lateral surfaces was accounted for by lipid-labeling. Analysis of the labeled apical and basal-lateral species by enzymatic digestion and thin layer chromatography disclosed that virtually all the radioactivity was present as mono-iodotyrosine (MIT). (orig./AJ)

  1. An anionic antimicrobial peptide from toad Bombina maxima.

    Lai, Ren; Liu, Hen; Hui Lee, Wen; Zhang, Yun

    2002-07-26

    Amphibian skin is a rich resource of antimicrobial peptides like maximins and maximins H from toad Bombina maxima. A novel cDNA clone encoding a precursor protein that comprises maximin 3 and a novel peptide, named maximin H5, was isolated from a skin cDNA library of B. maxima. The predicted primary structure of maximin H5 is ILGPVLGLVSDTLDDVLGIL-NH2. Containing three aspartate residues and no basic amino acid residues, maximin H5 is characterized by an anionic property. Different from cationic maximin H peptides, only Gram-positive strain Staphylococcus aureus was sensitive to maximin H5, while the other bacterial and fungal strains tested were resistant to it. The presence of metal ions, like Zn2+ and Mg2+, did not increase its antimicrobial potency. Maximin H5 represents the first example of potential anionic antimicrobial peptides from amphibians. The results provide the first evidence that, together with cationic antimicrobial peptides, anionic antimicrobial peptides may also exist naturally as part of the innate defense system. PMID:12127963

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

    MARCO A. MÉNDEZ; Eduardo R. Soto; Claudio Correa; Alberto Veloso; Eliseo Vergara; Michel Sallaberry; Patricia Iturra

    2004-01-01

    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 functi...

  3. A New Phylogeographic Pattern of Endemic Bufo bankorensis in Taiwan Island Is Attributed to the Genetic Variation of Populations

    Yu, Teng-Lang; Lin, Hung-Du; Weng, Ching-Feng

    2014-01-01

    Aim To comprehend the phylogeographic patterns of genetic variation in anurans at Taiwan Island, this study attempted to examine (1) the existence of various geological barriers (Central Mountain Ranges, CMRs); and (2) the genetic variation of Bufo bankorensis using mtDNA sequences among populations located in different regions of Taiwan, characterized by different climates and existing under extreme conditions when compared available sequences of related species B. gargarizans of mainland Ch...

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

    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 μg/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 μlg/L for Bufo maculatus and 0.126 - 0.159 μlg/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)

  5. New regional record and notes on historical specimens of Gunther Toad Duttaphrynus hololius with comments on other southeastern Indian congeners

    B. Srinivasulu

    2013-09-01

    Full Text Available We report on the finding of the Günther Toad Duttaphrynus hololius from Visakhapatnam and discuss aspects of its distribution based on our species distribution modeling. We also provide data on historically collected specimens and refine its intra-specific variation, provide an up-to-date chresonymy and comment on the validity of earlier reported diagnosis. Lastly, we remark on some misidentification-mediated dubious southern Indian records of another, related congener, the Marbled Toad D. stomaticus and correct some misallocations by referring them to another syntopic congener, the Dwarf Toad D. scaber.

  6. Effect of ethylenediaminetetraacetic acid (EDTA) on acute mercury poisoning of toad.

    Hilmy, A M; el-Domaity, N; Daabees, A Y

    1986-01-01

    Studies have been carried out on the ability of EDTA (CaNa2-ethylenediaminetetraacetate) to offset the acute toxicity of mercuric chloride. The lethality of mercury was tested in female Bufo regularis species (Amphibia) which were given EDTA immediately after the Hg2+ injection. The results show that the inherent toxicity of the EDTA-mercury complex is sufficiently high for it to be ineffective as an antidote. PMID:2877801

  7. Effects of amphibian chytrid fungus exposure on American toads in the presence of an insecticide.

    Wise, Rayona S; Rumschlag, Samantha L; Boone, Michelle D

    2014-11-01

    Abiotic factors such as pesticides may alter the impact of a pathogen on hosts, which could have implications for host-pathogen interactions and may explain variation in disease outbreaks in nature. In the present laboratory experiment, American toad (Anaxyrus americanus) metamorphs were exposed to the amphibian chytrid fungal pathogen Batrachochytrium dendrobatidis (Bd) and environmentally relevant concentrations of the insecticide malathion to determine whether malathion altered the effects of Bd exposure on growth and survival of toad metamorphs. Exposure to Bd significantly decreased survival over the 51 d of the experiment, suggesting that Bd could reduce recruitment into the terrestrial life stage when exposure occurs at metamorphosis. Malathion did not impact survival, but a 12-h exposure at metamorphosis significantly reduced terrestrial growth. Toads that were exposed to both Bd and malathion showed a nonsignificant trend toward the smallest growth compared with other treatments. The present study suggests that Bd may pose a threat to American toads even though population declines have not been observed for this species; in addition, the presence of both the insecticide malathion and Bd could reduce terrestrial growth, which could have implications for lifetime fitness and suggests that environmental factors could play a role in pathogen impacts in nature. PMID:25099070

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

    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

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

    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...

  10. Helpful invaders: Can cane toads reduce the parasite burdens of native frogs?

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

    2015-12-01

    Many invading species have brought devastating parasites and diseases to their new homes, thereby imperiling native taxa. Potentially, though, invaders might have the opposite effect. If they take up parasites that otherwise would infect native taxa, but those parasites fail to develop in the invader, the introduced species might reduce parasite burdens of the native fauna. Similarly, earlier exposure to the other taxon's parasites might 'prime' an anuran's immune system such that it is then able to reject subsequent infection by its own parasite species. Field surveys suggest that lungworm counts in native Australian frogs decrease after the arrival of invasive cane toads (Rhinella marina), and laboratory studies confirm that native lungworm larvae enter, but do not survive in, the toads. In laboratory trials, we confirmed that the presence of anurans (either frogs or toads) in an experimental arena reduced uptake rates of lungworm larvae by anurans that were later added to the same arena. However, experimental exposure to lungworms from native frogs did not enhance a toad's ability to reject subsequent infection by its own lungworm species. PMID:26236630

  11. Corticosterone-immune interactions during captive stress in invading Australian cane toads (Rhinella marina).

    Graham, Sean P; Kelehear, Crystal; Brown, Gregory P; Shine, Richard

    2012-07-01

    Vertebrates cope with physiological challenges using two major mechanisms: the immune system and the hypothalamic pituitary-adrenal axis (e.g., the glucocorticoid stress response). Because the two systems are tightly integrated, we need simultaneous studies of both systems, in a range of species, to understand how vertebrates respond to novel challenges. To clarify how glucocorticoids modulate the amphibian immune system, we measured three immune parameters and plasma corticosterone (CORT), before and after inflicting a stressor (capture and captive confinement) on introduced cane toads (Rhinella marina) near their invasion front in Australia. Stress increased CORT levels, decreased complement lysis capacity, increased leukocyte oxidative burst, and did not change heterologous erythrocyte agglutination. The strength of the CORT response was positively correlated with leukocyte oxidative burst, and morphological features associated with invasiveness in cane toads (relative leg length) were correlated with stress responsiveness. No immune parameter that we measured was affected by a toad's infection by a parasitic nematode (Rhabdias pseudosphaerocephala), but the CORT response was muted in infected versus uninfected toads. These results illustrate the complex immune-stress interactions in wild populations of a non-traditional model vertebrate species, and describe immune adaptations of an important invasive species. PMID:22713726

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

    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 Hμ 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 different

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

    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 μ 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.)

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

    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

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

    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.

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

    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

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

    Herkovits, J.; D’Eramo, J. L.; Fridman, O.

    2006-01-01

    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. PMID:16823076

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

    Cristina Silvia Pérez-Coll; Jorge Herkovits

    2007-01-01

    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 a...

  19. Alimentación de bufo marinus (linnaeus, 1758) (bufonidae: anura), en una localidad de sucre, colombia

    Sampedro Alcides; et al.

    2012-01-01

    Se realizaron recolectas nocturnas de Bufo marinus en una localidad del departamento de Sucre. Se recolectaron 197 ejemplares, de los cuales 128 fueron hembras y 69 machos. Los ejemplares fueron medidos y pesados y se les practicó una disección para extraer el estómago y determinar aspectos cualitativos (tipo de presas) y cuantitativos (número y tamaño de presas). Insectos del orden Hymenoptera fueron las presas de mayor importancia. Los individuos de mayor tamaño ingieren presas más grandes ...

  20. Effect Of The Apical Ectodermal Ridge On Mitotic Index In Hind Limb Bud Mesenchyme In Bufo Regularis

    Abdel Karim, Ahmed E. [???? ????? ??? ??????

    1991-01-01

    The apical ectodermal ridge (AER) was formed at stage 51 of Bufo regularis, it persisted at stage 52 (limb bud acquiring paddle-shaped outline), then it disappeared by stage 53 (first indication of fourth and fifth toes). Mitotic index (MI) in the AER (stage 51) was higher (40%) than that of the apical ectoderm at stage 50, then it decreased (15%) by stage 52. By apical ectoderm removal at stage 50, the wound epithelium formed an AER by stage 51. The operated bud (80% of cases) showed a decre...

  1. Regeneration of the optic tectum in larval stages of Bufo regularis Reuss after partial and total excision.

    Khalil, S H

    1989-01-01

    The right optic tectum of four larval stages of Bufo regularis was subjected to partial and total excision to determine the regenerative capacity of the optic tectum. Intense regenerative capacity can be observed at stage 50; the regenerated part grows to a considerable size and its structure is comparable to that of the intact part. This regenerative capacity gradually diminishes and from stage 55 onwards the decrease is pronounced. At stage 57 regenerative capacity is severly reduced and the regenerated part, if present, always has an anomalous structure. PMID:2606379

  2. Depth perception in frogs and toads a study in neural computing

    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. ...

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

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

    2014-01-01

    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 cannot 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 regardin...

  4. Two new species of cosmocercids (Ascaridida) in the toad Chaunus arenarum (Anura: Bufonidae) from Argentina.

    Ramallo, Geraldine; Bursey, Charles R; Goldberg, Stephen R

    2007-08-01

    Aplectana tarija n. sp. and Cosmocercoides lilloi n. sp., intestinal parasites of the toad Chaunus arenarum, are described. Of the 41 nominal species of Aplectana, A. tarija n. sp. represents the 22nd Neotropical species and the second species reported from Argentina. Of the 14 nominal species of Cosmocercoides, C. lilloi n. sp. represents the 15th species and the first species reported from South America. PMID:17918375

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

    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.

  6. Toxicity of trifluralin on the embryos and larvae of the red-bellied toad, Bombina bombina

    SAYIM, Ferah

    2010-01-01

    Many amphibian populations are in decline throughout the world, and one of the most important proposed causes for this decline is agrochemicals, especially pesticides. This study considers the effects of 120 h exposure of embryos and larvae of the red-bellied toad, Bombina bombina, to trifluralin, an herbicide, with renewal acute toxicity tests at 22 ± 1 °C. Adult males and females were induced to breed by gonadotropin injection to obtain test organisms. Lethal concentration values were deter...

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

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

    2013-01-01

    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 (Al...

  8. About a snail, a toad and rodents: animal models for adaptation research

    EricWRoubos

    2010-01-01

    Neural adaptation mechanisms have many similarities throughout the animal kingdom, enabling to study fundamentals of human adaptation in selected animal models with experimental approaches that are impossible to apply in man. This will be illustrated by reviewing research on three of such animal models, viz. (1) the egg-laying behavior of a snail, Lymnaea stagnalis: how one neuron type controls behavior, (2) adaptation to the ambient light condition by a toad, Xenopus laevis: how a neuroendoc...

  9. The declining spadefoot toad Pelobates fuscus: calling site choice and conservation

    Nyström, Per; Birkedal, L.; Dahlberg, C.; Brönmark, Christer

    2002-01-01

    We investigated whether local biotic and abiotic conditions could explain the occurrence of calling males of the declining spadefoot toad Pelobates fuscus in 72 ponds in southern Sweden. The ponds covered the entire distribution range of P. fuscus and were monitored during the breeding season in 2000. Calling males were found in 33 ponds. representing ca 50% of all known ponds for the species ill Sweden. They had a non-random distribution and a discriminant analysis including 19 environmental...

  10. Helminth parasites in the toad Rhinella major (Bufonidae from Chaco region, Argentina

    Monika I. Hamann

    2015-12-01

    Full Text Available The present study describes the diversity of helminth parasites of Rhinella major (Anura: Bufonidae in relation to their body size in 4 subhumid vs. semiarid sampling sites from the Argentine Chaco region. Helminths were found in 81% of the specimens examined (n = 85. Fifteen species (13 in subhumid and 7 in semiarid areas of helminth parasites were found, and most of them were nematodes. Parasites were found in all the examined organs, with highest prevalence and intensity in the digestive tract. Parasite transmission to the toad host occurs by skin penetration or oral ingestion. Maximum helminth richness ranged between 2 and 4 species per infected toad. The most abundant species was Aplectana hylambatis. Body size of the host was the main factor in determining parasite richness. The helminth parasite fauna was rather different in hosts from subhumid vs. semiarid sites, but the dominant (Aplectana hylambatis and codominant species (Cylindrotaenia sp. and Rhabdias elegans were the same. Mean species richness and mean species diversity of helminths were significantly different between the zones. These results suggest that the amount of rainfall and associated humidity affects the distribution and development of the parasite fauna of this toad.

  11. Description of two new species of Sicuophoridae and Nyctotheridae (Heterotrichina), endocommensal in the rectal ampulla of Bufo regularis (Amphibia: Anura) from the Northwest of Cameroon

    Fokam, Zéphyrin; Nana, Paul Alain; Ngassam, Pierre; Bricheux, Geneviève; Bouchard, Philippe; Vigues, Bernard; Sime-Ngando, Télesphore

    2013-01-01

    Prosicuophora cyclostomatus n. sp. and Nyctotheroides bambuiensis n. sp. are two new ciliate species isolated from the rectums of Bufo regularis collected in the vicinity of Bambili and Bambui. The morphological characteristics of these Protozoa are described and their relation to similar species is discussed.

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

    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.

  13. Living up to its name? The effect of salinity on development, growth, and phenotype of the "marine" toad (Rhinella marina).

    Wijethunga, Uditha; Greenlees, Matthew; Shine, Richard

    2016-02-01

    The highly permeable integument of amphibians renders them vulnerable to chemical characteristics of their environment, especially during the aquatic larval stage. As the cane toad (Rhinella marina, Bufonidae) invades southwards along the east coast of Australia, it is encountering waterbodies with highly variable conditions of temperature, pH, and salinity. Understanding the tolerance of toads to these conditions can clarify the likely further spread of the invader, as well as the adaptability of the species to novel environmental challenges. We measured salinity in waterbodies in the field and conducted laboratory trials to investigate the impacts of salinity on toad viability. Eggs and tadpoles from the southern invasion front tolerated the most saline conditions we found in potential spawning ponds during surveys [equivalent to 1200 ppm (3.5 % the salinity of seawater)]. Indeed, high-salinity treatments increased tadpole body sizes, accelerated metamorphosis, and improved locomotor ability of metamorphs (but did not affect metamorph morphology). At very low salinity [40 ppm (0.1 % seawater)], eggs hatched but larvae did not develop past Gosner stage 37. Our study shows that the egg and larval life stages of cane toads can tolerate wide variation in the salinity of natal ponds and that this aspect of waterbody chemistry is likely to facilitate rather than constrain continued southward expansion of the toad invasion front in eastern Australia. PMID:26553545

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

    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

  15. Total On-line Access Data System (TOADS): Phase II Final Report for the Period August 2002 - August 2004

    Yuracko, K. L. [YAHSGS LLC, Richland, WA (United States); Parang, M. [YAHSGS LLC, Richland, WA (United States); Landguth, D. C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Coleman, R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2004-09-13

    TOADS (Total On-line Access Data System) is a new generation of real-time monitoring and information management system developed to support unattended environmental monitoring and long-term stewardship of U.S. Department of Energy facilities and sites. TOADS enables project managers, regulators, and stakeholders to view environmental monitoring information in realtime over the Internet. Deployment of TOADS at government facilities and sites will reduce the cost of monitoring while increasing confidence and trust in cleanup and long term stewardship activities. TOADS: Reliably interfaces with and acquires data from a wide variety of external databases, remote systems, and sensors such as contaminant monitors, area monitors, atmospheric condition monitors, visual surveillance systems, intrusion devices, motion detectors, fire/heat detection devices, and gas/vapor detectors; Provides notification and triggers alarms as appropriate; Performs QA/QC on data inputs and logs the status of instruments/devices; Provides a fully functional data management system capable of storing, analyzing, and reporting on data; Provides an easy-to-use Internet-based user interface that provides visualization of the site, data, and events; and Enables the community to monitor local environmental conditions in real time. During this Phase II STTR project, TOADS has been developed and successfully deployed for unattended facility, environmental, and radiological monitoring at a Department of Energy facility.

  16. The genetics of amphibian decline: population substructure and molecular differentiation in the Yosemite toad, Bufo canorus (Anura, Bufonidae) based on single-strand conformation polymorphism analysis (SSCP) and mitochondrial DNA sequence data

    Shaffer, H.B.; Fellers, G.M.; Magee, A.; Voss, S.R.

    2000-01-01

    (1) DDT, dieldrin, and heptachlor were each applied to separate replicate plots in a hay field at 0.6, 2.2, or 9.0 kg/ha. For 11 yr thereafter, soil and earthworms were analysed for residues. (2) The average ratios of residues in earthworms (dry weight) to residues in soil (dry weight) were: total DDT, 5; dieldrin, 8; and heptachlor epoxide, 10. The average time for the initial residues in soil to be reduced by 50% were: total DDT, 3.2 yr; dieldrin, 5.1 yr; and heptachlor epoxide, 3.2 yr. The corresponding times for residues in earthworms were: total DDT, 3.2 yr; dieldrin, 2.6 yr; and heptachlor epoxide, 3.0 yr. (3) DDE was most persistent, and in plots treated at 9.0 kg/ha its concentration remained constant at about 0.4 ppm in soil and about 7 ppm in earthworms. (4) When applied at 9.0 kg/ha, DDT accumulated in earthworms to concentrations (32 ppm) which laboratory studies have shown to be hazardous to some sensitive bird species. When heptachlor was applied at 2.2 or 9.0 kg/ha, heptachlor epoxide in earthworms reached concentrations (8 ppm) potentially hazardous to woodcock. Dieldrin remained at potentially hazardous concentrations (8 ppm) for 3 yr in plots treated with 2.2 kg/ha and for 11 yr in plots treated with 9.0 kg/ha.

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

    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.

  18. 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

    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..

  19. Geology and mammalian paleontology of the Horned Toad Hills, Mojave Desert, California, USA

    May, S.R.; Woodburne, M.O.; Lindsay, E.H.; Albright, L.B.; Sarna-Wojcicki, A.; Wan, E.; Wahl, D.B.

    2011-01-01

    The Horned Toad Formation includes five lithostratigraphic members that record alluvial fan, fluvial, lake margin, and lacustrine deposition within a relatively small basin just south of the active Garlock fault during the late Miocene to early Pliocene. These sediments experienced northwest-southeast contractional deformation during the Pliocene-Pleistocene associated with basement-involved reverse faults. Member Two of the Horned Toad Formation has yielded 24 taxa of fossil mammals, referred to as the Warren Local Fauna, including Cryptotis sp., cf. Scapanus, Hypolagus vetus, Hypolagus edensis,? Spermophilus sp., Prothomomys warrenensis n. gen., n. sp., Perognathus sp., Repomys gustelyi, Postcopemys valensis, Peromyscus sp. A, Peromyscus sp. B, Jacobsomys dailyi n. sp., Borophagus cf. B. secundus, cf. Agriotherium, Machairodus sp. cf. M. coloradensis, Rhynchotherium sp. cf. R. edensis, Pliomastodon vexillarius, Dinohippus edensis, Teleoceras sp. cf. T. fossiger, cf. Prosthennops, Megatylopus sp. cf. M. matthewi, Hemiauchenia vera, Camelidae gen. et. sp. indet., and the antilocaprid cf. Sphenophalos. The majority of fossil localities are confined to a 20 m thick stratigraphic interval within a reversed polarity magnetozone. The fauna demonstrates affinity with other late Hemphillian faunas from California, Nevada, Nebraska, Texas, and Mexico. The Lawlor Tuff, dated elsewhere in California at 4.83 ?? 0.04 Ma and geochemically identified in the Horned Toad Formation, overlies most of the fossil mammal localities. Magnetic polarity data are correlated with Chrons 3n.3r, 3n.3n, and 3n.2r, suggesting an age of approximately 5.0 - 4.6 Ma. These constraints indicate an age for the late Hemphillian Warren Local Fauna of 4.85 - 5.0 Ma. ?? Society of Vertebrate Paleontology November 2011.

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

    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

  1. Effect of mechanical means on the restoration of the limb regenerative ability in metamorphic stages of Bufo regularis Reuss.

    Michael, M I; Aziz, F K

    1975-01-01

    Limbs of Bufo regularis REUSS metamorphic stages No. 57, 63 and 66 were transected at the thigh level. Removal of the apical skin cover on the third postoperative day, followed by traumatization after further two days in the limb stumps, was more effective in the enhancement of the regenerative ability than when each one of these procedures was performed independently. Better results were achieved in cases of the preclimactic stage (No. 57) where about 30% of the cases (Series III) developed heteromorphic limb outgrowths having more distal structures as the shank ending with or without toes. Normally, after transection at the same level, the limb stumps of this stage could restore part of the thigh region only. PMID:1220487

  2. Integrated all-optical logic and arithmetic operations with the help of a TOAD-based interferometer device--alternative approach.

    Roy, Jitendra Nath; Gayen, Dilip Kumar

    2007-08-01

    Interferometric devices have drawn a great interest in all-optical signal processing for their high-speed photonic activity. The nonlinear optical loop mirror provides a major support to optical switching based all-optical logic and algebraic operations. The gate based on the terahertz optical asymmetric demultiplexer (TOAD) has added new momentum in this field. Optical tree architecture (OTA) plays a significant role in the optical interconnecting network. We have tried to exploit the advantages of both OTA- and TOAD-based switches. We have proposed a TOAD-based tree architecture, a new and alternative scheme, for integrated all-optical logic and arithmetic operations. PMID:17676144

  3. A comparison of the uptake of [1-14C]palmitate into cell fractions of the perfused toad, chick and guinea-pig heart.

    Gloster, J; Achillea, M; Harris, P

    1977-01-01

    1. The incorporation and washout of [1-14C]palmitate in the subcellular fractions of toad, chick and guinea-pig hearts has been studied at warm and cold temperatures. 2. Maximal FFA radioactivity generally occurred in the microsomal fraction. Washout of radioactivity in chick and guinea-pig hearts virtually ceased in the cold, while in the toad it was only moderately affected. 3. The microsomal esterification process was temperature dependent. It was most active in the guinea-pig and least active in the toad. PMID:318436

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

    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.

  5. Behavioral and neural responses of toads to salt solutions correlate with basolateral membrane potential of epidermal cells of the skin

    Hillyard, Stanley D; Baula, Victor; Tuttle, Wendy; Willumsen, Niels J; Larsen, Erik H

    2007-01-01

    Dehydrated toads initiated water absorption response (WR) behavior and absorbed water from dilute NaCl solutions. With 200-250 mM NaCl, WR behavior and water absorption were both suppressed. With 200-250 mM Na-gluconate, WR initiation was significantly greater than with NaCl but water loss was gr...

  6. Aversive and non-reward learning in the fire-bellied toad using familiar and unfamiliar prey stimuli

    Ursula DICKE, Antje HEIDORN, Gerhard ROTH

    2011-12-01

    Full Text Available The present study investigated how snapping behavior toward familiar and unfamiliar prey is modified by reward omission and aversive conditioning in the fire-bellied toad Bombina orientalis. Toads were trained to snap at cricket images by rewarding them with live crickets. The task was learned, and the learning criterion (10 snapping responses within 2 minutes was reached in all individuals investigated. Subsequent reward omission did not alter the frequency of snapping to the familiar cricket stimulus. Snapping decreased only in some individuals, when a mild foot shock was applied at snapping. However, at presentation of images of hitherto unfamiliar meal worms and foot-shock application at snapping to the stimulus, the majority of toads diminished snapping significantly. Snapping responses decreased more rapidly, when snapping at meal worms was not rewarded or a footshock was applied uncorrelated to the presentation of or snapping at meal worms. These results demonstrate that in toads familiarity and unfamiliarity of prey stimuli are important factors in aversive learning, because well-trained responses to familiar stimuli become immune against reward omission. Furthermore, at presentation of unfamiliar stimuli, omission of reward and uncorrelated footshock had a stronger aversive effect than correlated footshock [Current Zoology 57 (6: 709–716, 2011].

  7. A burrowing frog from the late Paleocene of Mongolia uncovers a deep history of spadefoot toads (Pelobatoidea) in East Asia.

    Chen, Jianye; Bever, Gaberiel S; Yi, Hong-Yu; Norell, Mark A

    2016-01-01

    Fossils are indispensible in understanding the evolutionary origins of the modern fauna. Crown-group spadefoot toads (Anura: Pelobatoidea) are the best-known fossorial frog clade to inhabit arid environments, with species utilizing a characteristic bony spade on their foot for burrowing. Endemic to the Northern Hemisphere, they are distributed across the Holarctic except East Asia. Here we report a rare fossil of a crown-group spadefoot toad from the late Paleocene of Mongolia. The phylogenetic analysis using both morphological and molecular information recovered this Asian fossil inside the modern North American pelobatoid clade Scaphiopodidae. The presence of a spade and the phylogenetic position of the new fossil frog strongly support its burrowing behavior. The late Paleocene age and other information suggestive of a mild climate cast doubt on the conventional assertion that burrowing evolved as an adaptation to aridity in spadefoot toads. Temporally and geographically, the new fossil provides the earliest record of Scaphiopodidae worldwide, and the only member of the group in Asia. Quantitative biogeographic analysis suggests that Scaphiopodidae, despite originating in North America, dispersed into East Asia via Beringia in the Early Cenozoic. The absence of spadefoot toads in East Asia today is a result of extinction. PMID:26750105

  8. A burrowing frog from the late Paleocene of Mongolia uncovers a deep history of spadefoot toads (Pelobatoidea) in East Asia

    Chen, Jianye; Bever, Gaberiel S.; Yi, Hong-Yu; Norell, Mark A.

    2016-01-01

    Fossils are indispensible in understanding the evolutionary origins of the modern fauna. Crown-group spadefoot toads (Anura: Pelobatoidea) are the best-known fossorial frog clade to inhabit arid environments, with species utilizing a characteristic bony spade on their foot for burrowing. Endemic to the Northern Hemisphere, they are distributed across the Holarctic except East Asia. Here we report a rare fossil of a crown-group spadefoot toad from the late Paleocene of Mongolia. The phylogenetic analysis using both morphological and molecular information recovered this Asian fossil inside the modern North American pelobatoid clade Scaphiopodidae. The presence of a spade and the phylogenetic position of the new fossil frog strongly support its burrowing behavior. The late Paleocene age and other information suggestive of a mild climate cast doubt on the conventional assertion that burrowing evolved as an adaptation to aridity in spadefoot toads. Temporally and geographically, the new fossil provides the earliest record of Scaphiopodidae worldwide, and the only member of the group in Asia. Quantitative biogeographic analysis suggests that Scaphiopodidae, despite originating in North America, dispersed into East Asia via Beringia in the Early Cenozoic. The absence of spadefoot toads in East Asia today is a result of extinction. PMID:26750105

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

    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

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

    We have measured the total permeability coefficients P as a function of stirring frequency ω 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(ω); the result for frog skin is delta = (0.060 +- 0.016)/√ω(rad/s) cm. The stirring frequency range is from ω = 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

  11. Toxicity Effects of Toad (Rhinella jimi Stevaux, 2002) Venom in Chicken (Gallus gallus domesticus)

    Gadelha, Ivana Cristina Nunes; de Lima, Joseney Maia; Batista, Jael Soares; Melo, Marilia Martins

    2014-01-01

    This study aimed to evaluate the pathological changes that occur after administering different doses of R. jimi (Stevaux, 2002) parotoid glands secretion to Gallus gallus domesticus chicks. Twenty-three animals were used in this study and were divided into 5 groups that received a toad venom dose of 0, 3.0 mg/kg, 6.0 mg/kg, 10.0 mg/kg, and 25.0 mg/kg. After 48 h, the necropsy and pathological examinations were performed. No clinical signs of toxicity were observed in any group. Macroscopically, hepatomegaly, areas of liver necrosis, splenomegaly, necrotic and hemorrhagic cardiac regions, hydropericardium, dark necrotic lesions of Meckel's diverticulum, and hemorrhages in the lungs and kidneys were detected. Histopathological changes included diffuse vacuolar degeneration of hepatocytes, severe sinusoidal congestion, focal areas of hemorrhage in the parenchyma, swollen cardiac fibers, necrotic myocardial fibers, moderate to acute diffuse alveolar hemorrhage, vacuolar degeneration of the renal tubular epithelium, necrosis of renal tubules, and extensive hemorrhagic areas below the brain and cerebellar meninges. In conclusion, pathological changes of the R. jimi toxins in chicks were noted in the heart, spleen, liver, Meckel's diverticulum, lungs, and kidneys. Most of the changes were similar to those observed in humans and animals exposed to toxins from other toad species. PMID:25045748

  12. Blastema Volume And Nuclear Size In The Regenerating Hind Limbs In Larvae Of Xenopus Laevis And Bufo Regularis After Transection At The Ankle Level

    Abdel Karim, Ahmed E. [???? ????? ??? ??????

    1990-01-01

    After amputation at the ankle level of hind limbs in larval Xenopus laevis and Bufo regularis, an increase in the nuclear volume of blastema and stump tissue cells was observed. The cells in the distal region of blastema appeared to have the largest nuclei throughout the whole regenerating limb. In the stump, the increase in the nuclear volume was mostly confined to the distal region close to the amputation site, and a proximodistal gradient was pronouced. This might explain that amputation i...

  13. CRED Optical Validation Data at the island of Ofu and Olosega in American Samoa, 2012 to support Benthic Habitat Mapping (TOAD)

    National Oceanic and Atmospheric Administration, Department of Commerce — Optical validation data were collected using the Tethered Optical Assessment Device (TOAD), a sled equipped with underwater video camera, still camera and lights....

  14. Participation of MAPK, PKA and PP2A in the regulation of MPF activity in Bufo arenarum oocytes.

    Toranzo, G Sánchez; Bonilla, F; Bühler, M C Gramajo; Bühler, M I

    2011-05-01

    The objectives of the present paper were to study the involvement and possible interactions of both cAMP-PKA and protein phosphatases in Bufo arenarum oocyte maturation and to determine if these pathways are independent or not of the MAP kinase (MAPK) cascade. Our results indicated that the inhibition of PKA by treatment with H-89, an inhibitor of the catalytic subunit of PKA, was capable of inducing GVBD in a dose-dependent manner by a pathway in which Cdc25 phosphatase but not the MAPK cascade is involved. The injection of 50 nl of H-89 10 μM produced GVBD percentages similar to those obtained with treatment with progesterone. In addition, the assays with okadaic acid (OA), a PP2A inhibitor, significantly enhanced the percentage of oocytes that resumed meiosis by a signal transducing pathway in which the activation of the MEK-MAPK pathway is necessary, but in which Cdc25 phosphatase was not involved. Treatment with H-89, was able to overcome the inhibitory effect of PKA on GVBD; however, the inhibition of Cdc25 activity with NaVO3 was able to overcome the induction of GVBD by H-89. Although the connections between PKA and other signalling molecules that regulate oocytes maturation are still unclear, our results suggest that phosphatase Cdc25 may be the direct substrate of PKA. In Xenopus oocytes it was proposed that PP2A, a major Ser/Thr phosphatase present, is a negative regulator of Cdc2 activation. However, in Bufo arenarum oocytes, inhibition of Cdc25 with NaVO₃ did not inhibit OA-induced maturation, suggesting that the target of PP2A was not the Cdc25 phosphatase. MAPK activation has been reported to be essential in Xenopus oocytes GVBD. In B. arenarum oocytes we demonstrated that the inhibition of MAPK by PD 98059 prevented the activation of MPF induced by OA, suggesting that the activation of the MAPK cascade produced an inhibition of Myt1 and, in consequence, the activation of MPF without participation of the Cdc25 phosphatase. Our results suggest that in incompetent oocytes of B. arenarum two signal transduction pathways may be involved in the control of MPF activation: (1) the inhibition of phosphatase 2A that through the MEK-MAPK pathway regulates the activity of the Myt1; and (2) the inhibition of AMPc-PKA, which affects the activity of the Cdc25 phosphatase. PMID:20880425

  15. All-optical repetition rate multiplication of pseudorandom bit sequences based on cascaded TOADs

    Sun, Zhenchao; Wang, Zhi; Wu, Chongqing; Wang, Fu; Li, Qiang

    2016-03-01

    A scheme for all-optical repetition rate multiplication of pseudorandom bit sequences (PRBS) is demonstrated with all-optical wavelength conversion and optical logic gate 'OR' based on cascaded Tera-Hertz Optical Asymmetric Demultiplexers (TOADs). Its feasibility is verified by multiplication experiments from 500 Mb/s to 4 Gb/s for 23-1 PRBS and from 1 Gb/s to 4 Gb/s for 27-1 PRBS. This scheme can be employed for rate multiplication for much longer cycle PRBS at much higher bit rate over 40 Gb/s when the time-delay, the loss and the dispersion of the optical delay line are all precisely managed. The upper limit of bit rate will be restricted by the recovery time of semiconductor optical amplifier (SOA) finally.

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

    Larsen, Erik Hviid; Rasmussen, B E

    1983-01-01

    -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......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...... 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....

  17. Cytological evidence for population-specific sex chromosome heteromorphism in Palaearctic green toads (Amphibia, Anura)

    G Odierna; G Aprea; T Capriglione; S Castellano; E Balletto

    2007-06-01

    A chromosome study was carried out on a number of European and Central Asiatic diploid green toad populations by means of standard and various other chromosome banding and staining methods (Ag-NOR-, Q-, CMA3-, late replicating [LR] banding pattern, C- and sequential C-banding + CMA3 + DAPI). This study revealed the remarkable karyological uniformity of specimens from all populations, with the only exception being specimens from a Moldavian population, where one chromosome pair was heteromorphic. Though similar in shape, size and with an identical heterochromatin distribution, the difference in the heteromorphic pair was due to a large inverted segment on its long arms. This heteromorphism was restricted to females, suggesting a female heterogametic sex chromosome system of ZZ/ZW type at a very early step of differentiation.

  18. Advancement in research of anti-cancer effects of toad venom (ChanSu and perspectives

    Miao Liu

    2015-04-01

    Full Text Available Toad venom, called as ChanSu in China, is a widely used traditional Chinese medicine (TCM whose active components are mainly bufadienolides. ChanSu could exhibit cardiotonic, anti-microbial, anti-inflammatory and, most importantly, anti-cancer effects. In the present review, reports about the in vitro, in vivo and clinical anti-cancer effects of ChanSu or its representative component, bufalin, were summarized. And, reported anti-cancer mechanisms of cardenolides, structure analogues of bufadienolides, were also introduced. Based on the results got from research of ChanSu/bufalin and the results from cardenolides, possible signal network related to the anti-cancer effects of ChanSu/bufalin was predicted. Furthermore, future potential use of ChanSu in anti-cancer therapy was discussed.

  19. KARYOTYPIC STUDY OF THE COMMON INDIAN TOAD, DUTTAPHRYNUS MELANOSTICTUS, FROM JAMMU AND KASHMIR, INDIA

    Neelam Saba

    2014-01-01

    Full Text Available Karyotypic study of two sexes of the toad species, Duttaphrynus melanostictus, was carried out using giemsa staining, C- banding and NOR banding methods, from Jammu and Kashmir, India. The basic chromosome number was found to be 2n=22, fundamental arm number (NF was 44 with all the biarmed chromosomes and no sex chromosome heteromorphism was found. Cbanding and NOR banding was also performed. Paracentric C-band was on the long arm of first homologous pair. Centromeric heterochromatin appeared as darkly stained C-bands on all the chromosomes of diploid complement, whereas Ag-NOR staining showed a pair of nucleolar organizer regions present on pair no. 7 on short arm i.e. 7p in both male and female karyotypes.

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

    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.

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

    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.

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

    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.

  3. Ecological impact assessment in data-poor systems: a case study on metapopulation persistence.

    Etienne, Rampal S; Vos, Claire C; Jansen, Michiel J W

    2003-12-01

    Legislation on the protection of biodiversity (e.g., European Union Habitat and Bird Directives) increasingly requires ecological impact assessment of human activities. However, knowledge and understanding of relevant ecological processes and species responses to different types of impact are often incomplete. In this paper we demonstrate with a case study how impact assessment can be carried out for situations where data are scarce but some expert knowledge is available. The case study involves two amphibian species, the great crested newt (Triturus cristatus) and the natterjack toad (Bufo calamita) in the nature reserve the Meinweg in the Netherlands, for which plans are being developed to reopen an old railway track called the Iron Rhine. We assess the effects of this railway track and its proposed alternatives (scenarios) on the metapopulation extinction time and the occupancy times of the patches for both species using a discrete-time stochastic metapopulation model. We quantify the model parameters using expert knowledge and extrapolated data. Because of our uncertainty about these parameter values, we perform a Monte Carlo uncertainty analysis. This yields an estimate of the probability distribution of the model predictions and insight into the contribution of each distinguished source of uncertainty to this probability distribution. We show that with a simple metapopulation model and an extensive uncertainty analysis it is possible to detect the least harmful scenario. The ranking of the different scenarios is consistent. Thus, uncertainty analysis can enhance the role of ecological impact assessment in decision making by making explicit to what extent incomplete knowledge affects predictions. PMID:15160900

  4. The role of reactive oxygen species in the herbicide acetochlor-induced DNA damage on Bufo raddei tadpole liver.

    Liu, Yang; Zhang, Yingmei; Liu, Jianghai; Huang, Dejun

    2006-06-10

    After exposure of Bufo raddei tadpoles to acetochlor (ACETO) for 14 days, malondialdehyde (MDA) and DNA-single strand break (DNA-SSB) in livers were analyzed. An enhanced accumulation of MDA suggests that ACETO causes oxidative stress, and the significant increase in the level of DNA-SSB indicates that ACETO induces DNA damage in a dose-dependent manner as well. On the basis of the fact that oxidative stress is caused by excessive production of reactive oxygen species (ROS), and the present results, we speculate that ACETO-induced DNA damage may be a consequence of the generation of ROS. To evaluate this hypothesis, tadpoles were treated with ROS scavenger, N-acetyl-L-cysteine (NAC) or melatonin (MEL), prior to ACETO exposure. The decrease of DNA-SSB level and the increase of total antioxidant capability (TAC) show that ACETO-caused DNA damage can be attenuated by NAC and MEL. In addition, a negative correlation was observed between the extent of DNA damage and the level of TAC in tadpole liver. In conclusion, the results suggest that ACETO-induced DNA damage is mediated by ROS. PMID:16513190

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

    1983-01-01

    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 simil...

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

    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...

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

    Rago, Alfredo; While, Geoffrey M; Uller, Tobias

    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...

  8. Survey of helminths, ectoparasites, and chytrid fungus of an introduced population of cane toads, Rhinella marina (Anura: Bufonidae), from Grenada

    Drake, Michael C.; Zieger, Ulrike; Groszkowski, Andrew; Gallardo, Bruce; Sages, Patti; Reavis, Roslyn; Faircloth, Leslie; Jacobson, Krystin; Lonce, Nicholas; Pinckney, Rhonda D.; Cole, Rebecca Ann

    2014-01-01

    One hundred specimens of Rhinella marina, (Anura: Bufonidae) collected in St. George's parish, Grenada, from September 2010 to August 2011, were examined for the presence of ectoparasites and helminths. Ninety-five (95%) toads were parasitized by one or more parasite species. Nine species of parasites were found: 1 digenean, 2 acanthocephalans, 4 nematodes, 1 arthropod and 1 pentastome. The endoparasites represented 98.9% of the total number of parasite specimens collected. Grenada represents a new locality record for Mesocoelium monas, Raillietiella frenatus, Pseudoacanthacephalus sp., Aplectana sp., Physocephalus sp., Acanthacephala cystacanth and Physalopteridae larvae. The digenean M. monas occurred with the highest prevalence of 82%, contrasting many studies of R. marina where nematodes dominate the parasite infracommunity. Female toads were found to have a significantly higher prevalence of Amblyomma dissimile than male toads. Only two parasites exhibited a significant difference between wet and dry season with Parapharyngodon grenadensis prevalence highest in the wet season and A. dissimile prevalence highest during the dry season. Additionally, A. dissimile was significantly more abundant during the dry season.

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

    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].

  10. Sexual dimorphism in baseline urinary corticosterone metabolites and their association with body-condition indices in a peri-urban population of the common Asian toad (Duttaphrynus melanostictus).

    Narayan, Edward J; Gramapurohit, Narahari P

    2016-01-01

    Field endocrinology research through the quantification of glucocorticoids or stress hormones in free-living wildlife is crucial for assessing their physiological responses towards pervasive environmental changes. Urinary corticosterone metabolite (UCM) enzyme-immunoassay (EIA) has been validated for numerous amphibian species as a non-invasive measure of physiological stress. Body-condition indices (BCIs) have also been widely used in amphibians as an indirect measure of animal health. Field endocrinology research on amphibian species in Asia is limited. In this study, we validated a UCM EIA in a peri-urban sub-population of the common Asian toad (Duttaphrynus melanostictus) in Pune, Maharashtra, India. We determined the baseline levels of UCMs in male (n=39) and female (n=19) toads. Secondly, we used a standard capture handling protocol to quantify changes in UCMs during short-term captivity. We also determined BCIs in the male and female toads using Fulton's index (K) and residual condition index (RCI). The results showed that mean baseline levels of UCMs were significantly higher in male toads than in females. There was no significant change in mean levels of UCMs of males and females between capture and captivity (0-12h). This highlights plausible habituation of the species to the peri-urban environment. Associations between UCMs with BCIs (K and R) were positive in male toads but negative in females. In conclusion, our UCMs EIA can be applied with BCIs to assess health of the Asian toads. We also suggest that direct fitness parameters such as sperm and oocyte quality, reproductive ecology and immunocompetence measurements should be applied in combination with these conservation physiology tools to quantify the fitness consequences of pervasive environmental changes on native amphibians. PMID:26478192

  11. Differential uptake of endosulfan in the South American toad under sublethal exposure.

    Svartz, Gabriela; Marino, Damián; Ronco, Alicia; Pérez Coll, Cristina S

    2015-07-01

    Agroecosystems are usually polluted with a wide variety of contaminants with pesticides being very frequently detected. Endosulfan, an organochlorine pesticide, has been shown to cause both lethal and sublethal effects on aquatic organisms such as amphibians and especially on its early developmental stages. In this context, the aim of this study was to evaluate the uptake of environmentally relevant concentrations of endosulfan and its correlation with differential sensitivity in the early development stages of the common South American toad, Rhinella arenarum. Embryos and larvae were exposed to sublethal concentrations of endosulfan for several periods of exposures. According to the developmental stage at which they were exposed, the uptake rate was different. Bioconcentration factors (BCFs) for embryos significantly decreased with exposure time and concentration (p < 0.05) reaching a BCF of ≤1679 for embryos at 96 h of exposure to 0.001 mg endosulfan L(-1). BCFs for larvae significantly increased with exposure time (p < 0.05) obtaining a maximum of 40 at 504 h. In our previous study, we reported that embryos were less sensitive to the effects of endosulfan than larvae, which is in line with the main tendency of embryos to bioconcentrate endosulfan as observed in this study. PMID:25994079

  12. Parotoid macroglands in toad (Rhinella jimi): their structure and functioning in passive defence.

    Jared, Carlos; Antoniazzi, Marta M; Jordão, Amarildo E C; Silva, José Roberto M C; Greven, Hartmut; Rodrigues, Miguel T

    2009-09-01

    When toads (Rhinella) are threatened they inflate their lungs and tilt the body towards the predator, exposing their parotoid macroglands. Venom discharge, however, needs a mechanical pressure onto the parotoids exerted by the bite of the predator. The structure of Rhinella jimi parotoids was described before and after manual compression onto the macroglands mimicking a predator attack. Parotoids are formed by honeycomb-like collagenous alveoli. Each alveolus contains a syncytial gland enveloped by a myoepithelium and is provided with a duct surrounded by differentiated glands. The epithelium lining the duct is very thick and practically obstructs the ductal lumen, leaving only a narrow slit in the centre. After mechanical compression the venom is expelled as a thin jet and the venom glands are entirely emptied. The force applied by a bite of a potential predator may increase alveolar pressure, forcing the venom to be expelled as a thin jet through the narrow ductal slit. We suggest that the mechanism for venom discharge within all bufonids is possibly similar to that described herein for Rhinella jimi and that parotoids should be considered as cutaneous organs separate from the rest of the skin specially evolved for an efficient passive defence. PMID:19374917

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

    J.E.S. Natali

    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 cannot 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<0.01. These results indicate that R. jimi has a lower thermal sensitivity and that cardiac control is not completely dependent on the thermal environment because HRC was not consistently different between temperatures in all R. jimi specimens. This result indicates a lack of evolutive trade-offs among temperatures given that heart rate control at 25°C is potentially not a constraint to heart rate control at 15°C.

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

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

    2015-01-01

    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 cannot 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 Ptemperatures in all R. jimi specimens. This result indicates a lack of evolutive trade-offs among temperatures given that heart rate control at 25°C is potentially not a constraint to heart rate control at 15°C. PMID:25493382

  15. Protein synthesis inhibitors attenuate water flow in vasopressin-stimulated toad urinary bladder

    Vasopressin stimulates the introduction of aggregated particles, which may represent pathways for water flow, into the luminal membrane of toad urinary bladder. It is not known whether water transport pathways are degraded on removal from membrane or whether they are recycled. The authors examined the effect of the protein synthesis inhibitors cycloheximide and puromycin using repeated 30-min cycles of vasopressin followed by washout of vasopressin, all in the presence of an osmotic gradient, a protocol that maximizes aggregate turnover. High dose cycloheximide inhibited flow immediately. Low dose cycloheximide did not affect initial flow. In the absence of vasopressin, inhibition did not develop. Despite the inhibition of flow in vasopressin-treated tissues, the cAMP-dependent protein kinase ratio was elevated in cycloheximide-treated tissues, suggesting modulation at a distal site in the stimulatory cascade. [14C]urea permeability was not inhibited by cycloheximide. Puromycin also inhibited water flow by the fourth challenge with vasopressin. The data suggest that protein synthesis inhibitors attenuate flow at a site that is distal to cAMP-dependent protein kinase. However, the reversal of inhibition in MIX-treated tissues suggests that the water pathway can be fully manifested given suitable stimulation. They conclude that either large stores of the transport system are available or that the transport system is extensively recycled on retrieval from the membrane

  16. Age structure, growth and longevity in the common toad, Rhinella arenarum, from Argentina

    Clarisa de L. Bionda

    2015-06-01

    Full Text Available Age structure, growth and longevity was determined in the common toad, Rhinella arenarum, from a suburban pond located in the Pampa plains, central Argentina during two breeding seasons, in 2000 and 2008 by using skeletochronology, which relies on the analysis of the annual lines of arrested growth (LAGs in bones. Both females and males were captured in 2008, while only males were recorded in 2000. Females were significantly larger than males. Mean population age was 2.4 ± 0.9 years in 2000. In 2008, the difference in age was not significant between the sexes (Males: 3.0 ± 0.7, n = 21; Females: 2.6 ± 0.9, n = 12, neither between males in 2000 and 2008. The longevity in males of 2000 was 6 LAGs and exceeded that of males (5 LAGs and females (4 LAGs in 2008. Von Bertalanffy curves showed that the growth coefficient in the males of 2000 (K = 2.97 ± 0.47 was almost double that of females (K = 1.21 ± 0.10 and males (K = 1.01 ± 0.14 of 2008. Males and females Rhinella arenarum show different morphological and life history traits and the year of sampling can significantly influence the estimation of the studied parameters such as age at maturity and growth rates.

  17. Electron-microscopic study of the apical region of the toad bladder epithelial cell.

    Sasaki, J; Tilles, S; Condeelis, J; Carboni, J; Meiteles, L; Franki, N; Bolon, R; Robertson, C; Hays, R M

    1984-09-01

    Antidiuretic hormone (ADH) promotes fusion of cytoplasmic tubules with the luminal membrane and delivery of particles from the tubules to the membrane. The particles are believed to be the water-conducting elements in the membrane. We have employed several scanning (SEM) and transmission electron-microscopic (TEM) techniques to study the relationship of the cytoplasmic tubules to the luminal membrane and to the apical cytoskeleton of the toad bladder epithelial cell. This paper reports the results of freeze-crack SEM and tannic acid-fixed TEM studies, as well as studies with a resinless method of embedding. Freeze-cracked epithelial cells reveal that the tubules are anchored in a matrix of cytoskeleton and granules just below the luminal membrane, and many, if not all, retain their anchorage to the matrix after ADH-induced fusion. Tannic acid-fixed specimens show that the tubules in unstimulated cells lie horizontally. Fusion appears to involve an angulation of the tubules, and this may be the major mode of ADH-induced tubule movement. There are suggestions in the tannic acid sections of filamentous attachments of tubules to the surrounding cytoskeleton. In addition there are prominent microfilament bundles running down the microvilli and a dense concentration of filaments just below the luminal membrane. The presence of these filaments is confirmed in the resinless sections, and their possible role in ADH action is discussed. PMID:6433717

  18. About a snail, a toad and rodents: animal models for adaptation research

    EricWRoubos

    2010-10-01

    Full Text Available Neural adaptation mechanisms have many similarities throughout the animal kingdom, enabling to study fundamentals of human adaptation in selected animal models with experimental approaches that are impossible to apply in man. This will be illustrated by reviewing research on three of such animal models, viz. (1 the egg-laying behavior of a snail, Lymnaea stagnalis: how one neuron type controls behavior, (2 adaptation to the ambient light condition by a toad, Xenopus laevis: how a neuroendocrine cell integrates complex external and neural inputs, and (3 stress, feeding and depression in rodents: how a neuronal network co-ordinates different but related complex behaviors. Special attention is being paid to the actions of neurochemical messengers, such as neuropeptide Y, urocortin 1 and brain-derived neurotrophic factor. While awaiting new technological developments to study the living human brain at the cellular and molecular levels, continuing progress in the insight in the functioning of human adaptation mechanisms may be expected from neuroendocrine research using invertebrate and vertebrate animal models.

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

    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.

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

    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 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

  1. Angiotensin-(1-7 increases osmotic water permeability in isolated toad skin

    Santos J.C.

    2000-01-01

    Full Text Available Angiotensin-(1-7 (Ang-(1-7 increased osmotic water permeability in the isolated toad skin, a tissue with functional properties similar to those of the distal mammalian nephron. Concentrations of 0.1 to 10 µM were effective, with a peak at 20 min. This effect was similar in magnitude to that of frog skin angiotensin II (Ang II and oxytocin but lower than that of human Ang II and arginine-vasotocin. The AT2 angiotensin receptor antagonist PD 123319 (1.0 µM fully inhibited the response to 0.1 µM Ang-(1-7 but had no effect on the response to Ang II at the same concentration. The specific receptor antagonist of Ang-(1-7, A-779, was ineffective in blocking the response to Ang-(1-7 and to frog skin Ang II. The AT1 receptor subtype antagonist losartan, which blocked the response to frog skin Ang II, was ineffective in blocking the response to Ang-(1-7. The present results support the view of an antidiuretic action of Ang-(1-7 in the mammalian nephron.

  2. Variety of antimicrobial peptides in the Bombina maxima toad and evidence of their rapid diversification.

    Lee, Wen-Hui; Li, Yan; Lai, Ren; Li, Sha; Zhang, Yun; Wang, Wen

    2005-04-01

    Antimicrobial peptides secreted by the skin of many amphibians play an important role in innate immunity. From two skin cDNA libraries of two individuals of the Chinese red belly toad (Bombina maxima), we identified 56 different antimicrobial peptide cDNA sequences, each of which encodes a precursor peptide that can give rise to two kinds of antimicrobial peptides, maximin and maximin H. Among these cDNA, we found that the mean number of nucleotide substitution per non-synonymous site in both the maximin and maximin H domains significantly exceed the mean number of nucleotide substitution per synonymous site, whereas the same pattern was not observed in other structural regions, such as the signal and propiece peptide regions, suggesting that these antimicrobial peptide genes have been experiencing rapid diversification driven by Darwinian selection. We cloned and sequenced seven genes amplified from skin or liver genomic DNA. These genes have three exons and share the same gene structure, in which both maximin and maximin H are encoded by the third exon. This suggests that alternative splicing and somatic recombination are less likely to play a role in creating the diversity of maximins and maximin Hs. The gene trees based on different domain regions revealed that domain shuffling or gene conversion among these genes might have happened frequently. PMID:15770703

  3. Maximins S, a novel group of antimicrobial peptides from toad Bombina maxima.

    Wang, Ting; Zhang, Jie; Shen, Ji-Hong; Jin, Yang; Lee, Wen-Hui; Zhang, Yun

    2005-02-18

    Amphibian skin secretions are rich in antimicrobial peptides acting as important components of innate defense system against invading microorganisms. A novel type of peptide, designated as maximin S, was deduced by random sequencing of 793 clones from a constructed Bombina maxima skin cDNA library. The putative primary structures of maximin S peptides can be grouped into five species, in which maximin S1 has 14 amino acid residues and the rest of maximin S peptides (S2-S5) all have 18 amino acid residues. Unlike most of the amphibian antimicrobial peptides so far identified, the newly characterized four maximin S precursors are composed of maximin S1 and different combinations of tandem repeated maximin S2-S5 linked by internal peptides. Except maximin S1, the predicted secondary structures of maximin S2-S5 show a similar amphipathic alpha-helical structure. MALDI-TOF mass spectrometry analysis of partially isolated skin secretions of the toad indicates that most of the deduced maximin S peptides are expressed. Two deduced maximin S peptides (S1, S4) were synthesized and their antimicrobial activities were tested. Maximin S4 only had an antibiotic activity against mycoplasma and had no antibacterial or antifungal activity toward tested strains. Maximin S1 had no activity under the same conditions. PMID:15649437

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

    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 χ2 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.

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

    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.

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

    Greenberg, Cathryn H. [USDA Forest Service, New Ellenton, SC (United States); Tanner, George W. [USDA Forest Service, New Ellenton, SC (United States)

    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.

  7. Patterns of Genetic Variability in Island Populations of the Cane Toad (Rhinella marina) from the Mouth of the Amazon

    Bessa-Silva, Adam Rick; Vallinoto, Marcelo; Sodré, Davidson; da Cunha, Divino Bruno; Hadad, Dante; Asp, Nils Edvin; Sampaio, Iracilda; Schneider, Horacio; Sequeira, Fernando

    2016-01-01

    The Amazonian coast has several unique geological characteristics resulting from the interaction between drainage pattern of the Amazon River and the Atlantic Ocean. It is one of the most extensive and sedimentologically dynamic regions of the world, with a large number of continental islands mostly formed less than 10,000 years ago. The natural distribution of the cane toad (Rhinella marina), one of the world’s most successful invasive species, in this complex Amazonian system provides an intriguing model for the investigation of the effects of isolation or the combined effects of isolation and habitat dynamic changes on patterns of genetic variability and population differentiation. We used nine fast-evolving microsatellite loci to contrast patterns of genetic variability in six coastal (three mainlands and three islands) populations of the cane toad near the mouth of the Amazon River. Results from Bayesian multilocus clustering approach and Discriminant Analyses of Principal Component were congruent in showing that each island population was genetically differentiated from the mainland populations. All FST values obtained from all pairwise comparisons were significant, ranging from 0.048 to 0.186. Estimates of both recent and historical gene flow were not significantly different from zero across all population pairs, except the two mainland populations inhabiting continuous habitats. Patterns of population differentiation, with a high level of population substructure and absence/restricted gene flow, suggested that island populations of R. marina are likely isolated since the Holocene sea-level rise. However, considering the similar levels of genetic variability found in both island and mainland populations, it is reliable to assume that they were also isolated for longer periods. Given the genetic uniqueness of each cane toad population, together with the high natural vulnerability of the coastal regions and intense human pressures, we suggest that these populations should be treated as discrete units for conservation management purposes. PMID:27073849

  8. Conservation threats and the phylogenetic utility of IUCN Red List rankings in Incilius toads.

    Schachat, Sandra R; Mulcahy, Daniel G; Mendelson, Joseph R

    2016-02-01

    Phylogenetic analysis of extinction threat is an emerging tool in the field of conservation. However, there are problems with the methods and data as commonly used. Phylogenetic sampling usually extends to the level of family or genus, but International Union for Conservation of Nature (IUCN) rankings are available only for individual species, and, although different species within a taxonomic group may have the same IUCN rank, the species may have been ranked as such for different reasons. Therefore, IUCN rank may not reflect evolutionary history and thus may not be appropriate for use in a phylogenetic context. To be used appropriately, threat-risk data should reflect the cause of extinction threat rather than the IUCN threat ranking. In a case study of the toad genus Incilius, with phylogenetic sampling at the species level (so that the resolution of the phylogeny matches character data from the IUCN Red List), we analyzed causes of decline and IUCN threat rankings by calculating metrics of phylogenetic signal (such as Fritz and Purvis' D). We also analyzed the extent to which cause of decline and threat ranking overlap by calculating phylogenetic correlation between these 2 types of character data. Incilius species varied greatly in both threat ranking and cause of decline; this variability would be lost at a coarser taxonomic resolution. We found far more phylogenetic signal, likely correlated with evolutionary history, for causes of decline than for IUCN threat ranking. Individual causes of decline and IUCN threat rankings were largely uncorrelated on the phylogeny. Our results demonstrate the importance of character selection and taxonomic resolution when extinction threat is analyzed in a phylogenetic context. PMID:26243724

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

    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.

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

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

    2011-01-01

    Roč. 6, č. 4 (2011), e18871. E-ISSN 1932-6203 R&D Projects: GA AV ČR KJB600960701 Grant ostatní: GA ČR(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

  11. The rediscovery of Perret’s toad, Amietophrynus perreti (Schiøtz, 1963 after more than 40 years, with comments on the species’ phylogenetic placement and conservation status

    Abiodun B. Onadeko

    2014-10-01

    Full Text Available Perret’s toad, Amietophrynus perreti, has not been seen since 1970 and thus believed to be lost. We searched for the species 50 years after its original description and successfully recorded its continued presence at the type locality, where it seems to maintain a viable population. We failed however, to record the species at suitable sites elsewhere and A. perreti could thus indeed be a micro-endemic species, specialized and restricted to the granite inselbergs of the Idanre Hills, Nigeria. We recorded and discuss potential threats and suggest keeping the toad’s current conservation status as ‘Vulnerable’. We investigated the systematic status of Perret’s toad using a mitochondrial fragment of the 16S rRNA gene and could confirm that it is a member of the genus Amietophrynus despite its aberrant larval biology, different to the rest of the genus. In spite of this biological difference, A. perreti is not a phylogenetically isolated lineage, but is nested within a clade of western African Amietophrynus species, such as A. maculatus, A. regularis, A. latifrons and A. togoensis and is sister to the widespread and savannah dwelling A. maculatus.

  12. Studies of Zn, Mg, Cu, Ca and Fe in cadmium poisoned toads before and after treatment with EDTA.

    Hilmy, A M; el-Domiaty, N A; Daabees, A Y; Abou-Taleb, E M

    1986-01-01

    Zn, Mg, Cu, Ca and Fe were determined spectrophotometrically in liver, kidneys, muscle, spleen and blood of Bufo regularis after a single i.m. injection of 6.2 mg Cd/kg (which represents the 96 hr LD50) alone or in combination with 40 mg EDTA/kg (the minimal EDTA concentration causing 100% survival over that period). Cadmium administration caused recognizable effects on the essential metals levels in different tissues and organs. In the majority of the tissues and organs studied, zinc and copper concentrations returned to their normal ranges in animals that received both cadmium and EDTA. In contrast, magnesium, calcium and iron contents not only returned back to their control values but also exceeded them. PMID:2877783

  13. Dynamic sexual dichromatism produces a sex signal in an explosively breeding Neotropical toad: A model presentation experiment.

    Rehberg-Besler, Nicolas; Mennill, Daniel J; Doucet, Stéphanie M

    2015-12-01

    Many animals breed in large mating aggregations, where males must rapidly discriminate between prospective mates and rivals. Selection may favour features that facilitate rapid discrimination in these aggregations. The explosively breeding Neotropical Yellow Toad, Incilius luetkenii, exhibits a rapid and dramatic colour change; males change from a cryptic brown to a conspicuous lemon yellow for their brief breeding period. Females, in contrast, remain cryptic brown throughout the year. The function of this temporary, sex-specific colour change is unknown. We tested the hypothesis that yellow colouration displayed by male I. luetkenii facilitates sex recognition during both daytime and nighttime mating aggregations. We created yellow and brown model toads and presented them to males during a breeding event. Male I. luetkenii responded significantly more intensely to brown models compared to yellow models, approaching them and making more amplexus attempts on the brown versus yellow models. This strong pattern held true regardless of ambient light intensity, making this the first study to expose a dynamic colour signal that operates during both day and night. Our results indicate that male I. luetkenii use colouration to quickly discriminate between males and females during their brief, explosive mating aggregations. Our findings suggest that the rapid, dramatic colour change of male I. luetkenii facilitates sex recognition, which could provide a significant fitness advantage to males in the form of reduced energy expenditure and reduced risk of injury by other males. Dynamic dichromatism may provide similar fitness benefits in any organisms that mate in large, competitive aggregations. PMID:26454154

  14. Insulin-induced alterations in the lactoperoxidase-catalyzed radioiodination of membrane proteins of the toad bladder epithelium

    Insulin-stimulated sodium transport in the toad urinary bladder consists of two components, a brief element of rapid onset that is independent of protein synthesis, and a sustained increase, slower in onset, that is dependent upon RNA and protein synthesis. The mucosal epithelium of the toad bladder was labeled by lactoperoxidase-catalyzed radioiodination (125I) following 15 min and 3 h exposure to insulin. The membrane of ''mitochondria-rich'' and ''granular'' mucosal cells from these tissues were analyzed by electrophoresis in SDS-urea. Compared to untreated tissues, membranes of ''granular'' mucosal cells from tissues exposed to insulin for 15 min contained a band (Mr . 15,000) with significantly increased labeling. Bladders exposed to insulin for 3 h showed no consistent increase in labeling. These data suggest that there are differences in the conformation of apical membrane proteins during the two phases of hormone-induced sodium transport. The technique may also offer an opportunity to identify ''effector'' proteins mediating this and other insulin responses

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

    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.

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

    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.

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

    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.

  18. 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)

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

    2008-01-01

    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, β-and α-catenin in the developing kidney of Bufo arenarum. Cell adhesion molecules have selective temporal and spatial expression during development sug...

  19. The complete mitochondrial genome of the toad-headed lizard subspecies, Phrynocephalus theobaldi orientalis (Reptilia, Squamata, Agamidae).

    Liao, Pinghu; Jin, Yuanting

    2016-01-01

    The first complete mitochondrial genome sequence of Phrynocephalus viviparity was determined for the toad-headed lizard Phrynocephalus theobaldi orientalis. The 16,608 bp mitogenome contains 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and 2 control regions (CRs). The overall base composition of H-strand is T: 26.7%, C: 24.5%, A: 37.6%, G: 11.2%. The gene arrangement and composition of P. theobaldi orientalis was similar to other published mitochondrial genomes of Phrynocephalus oviparity, except that tRNA-Phe and tRNA-Pro were exchanged. The control region comprised two parts, one between tRNA-Thr and tRNA-Phe and another between tRNA-Pro and 12S RNA. The complete mitogenome sequence of P. theobaldi orientalis provided fundamental data for resolving phylogenetic and genetic problems related to Phrynocephalus viviparity. PMID:24708124

  20. Changes of body fluid and hematology in toad and their rehabilitation following intermittent exposure to simulated high altitude

    Biswas, H. M.; Boral, M. C.

    1986-06-01

    Three groups of adult male toads were exposed intermittently in a decompression chamber for a daily period of 4 and 8 hours at a time for 6 consecutive days to an “altitude” of 12,000; 18,000 and 24,000 feet (3658; 5486; 7315 m) respectively. Most of the exposed animals were sacrificed immediately after the last exposure, but only a few animals experiencing 8 hours of exposure were sacrificed after a further 16 hours of exposure at normal atmospheric pressure. Eight hours of daily exposure for 6 days causes a decrease of body fluids and an increase of hematological parameters in all the altitude exposed animals compared with to the changes noted in the animals having 4 hours of daily exposure for 6 days at the same altitude levels. The animals that were exposed to pressures equivalent to altitudes of 12,000 and 18,000 feet daily for 8 hours were found to return nearly to their normal body fluids and hematological balance after 16 hours of exposure to normal atmospheric pressure, whereas the animals exposed for a similar period at an equivalent 24,000 feet failed to get back their normal balance of body fluids and hematology after 16 hours of exposure at normal atmospheric pressure. The present experiment shows that the body weight loss and changes of body fluid and hematological parameters in the toad after exposure to simulated high altitude are due not only to dehydration, but suggest that hypoxia may also have a role.

  1. A low molecular weight protein with antimicrobial activity in the cutaneous 'venom' of the yellow-bellied toad (Bombina variegata pachypus).

    Barberio, C; Delfino, G; Mastromei, G

    1987-01-01

    The cutaneous 'venom' was collected from dorsal skin fragments of the yellow-bellied toad Bombina variegata pachypus by means of stimulation with noradrenaline. Light and electron microscope observations gave evidence that the 'venom' corresponds to the secretory products of both serous gland types (i.e. with small or large granules) characteristic of this genus, which had discharged their contents upon stimulation. The serous 'venom', when tested for antimicrobial activity, inhibited the growth of several bacterial strains. Heat treatment, dialysis, protease digestion and SDS-PAGE electrophoresis showed that the antimicrobial activity was thermostable and associated with a low molecular weight protein. This protein was purified and homogeneity determined by CM-cellulose chromatography and SDS-PAGE electrophoresis. The purified protein has a molecular weight of 6700, displays antibacterial properties and appears different from the antimicrobially active peptides previously isolated from the 'venom' of the toad. PMID:3672549

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

    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.

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

    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.

  4. Phylogeography of the African Common Toad, Amietophrynus regularis, Based on Mitochondrial DNA Sequences: Inferences Regarding the Cape Verde Population and Biogeographical Patterns

    Vasconcelos, Raquel; Froufe, E.; Carranza, Salvador; Harris, David James

    2010-01-01

    The amphibian Amietophrynus regularis is distributed throughout equatorial Africa, with presumed introduced populations in the Cape Verde archipelago. Portions of the 12S and 16S rRNA mitochondrial regions of 30 specimens from Kenya, Uganda, Niger, Mali, Burkina-Faso, Ghana, Guinea-Bissau and Cape Verde were used to assess genetic diversity and to identify the most probable geographic origin for the introduction of this toad on the latter archipelago. Two lineages with 1.4% genetic divergence...

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

    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...

  6. 5alpha-REDUCTASE, AN ENZYME REGULATING GLUCOCORTICOID ACTION IN THE TESTIS OF THE TOAD Rhinella arenarum.

    Eleonora Regueira

    2011-07-01

    Full Text Available The sensitivity of Leydig cells to glucocorticoids (GC is determined by several factors: plasma levels of GC and corticosteroid binding globulins, the amount of GC receptors (GR and the activating/inactivating enzyme 11?-hydroxysteroid dehydrogenase, among others. In the toad Rhinella arenarum, breeding levels of corticosterone (B inhibit testosterone synthesis by suppressing the cytochrome P450 17-hydroxylase, C17,20-lyase (Cyp450c17 via GR-mediated mechanism. Anurans express a high testicular activity of 5alpha-reductase (5alphaRed, enzyme that could contribute to modulate GC action by the irreversible reduction of the A-ring of GC. The objective of this work was to study the role of 5alphaRed on GC action in toad testes. Enzymatic activity was assayed with [3H]B and [3H]testosterone as substrates. The binding capacity of 5alpha-dihydrocorticosterone (5alphaDHB to testicular GR was determined by the displacement of [3H]dexamethasone with radioinert B and 5alphaDHB. For analyzing the agonistic/antagonistic properties of 5alphaDHB, the effect of dexamethasone and 5alphaDHB on the activity of Cyp450c17 was measured after culturing testes with both steroids. Results indicate that 5alphaRed localizes in microsomes with the highest activity at pH between 6.0 and 8.0. Kinetic parameters, Km and Vmax, do not change along the year. The affinity of the enzyme for B was significantly higher than for testosterone, indicating that B is the preferred substrate. Competition studies show that 5alphaDHB displaces the binding of [3H]dexamethasone with a similar potency than B (Kd for B and 5alphaDHB, 31.33 and 35.24 nM, respectively, suggesting that 5alphaDHB could compete with B for GR. Moreover, long-term incubation of testes with 5alphaDHB (150 and 1500 nM inhibits the activity of the key enzyme of androgen biosynthesis, Cyp450c17, similarly than dexamethasone. This result is consistent with an agonistic activity and suggests that 5alphaDHB could be part of the activating mechanism.

  7. Detection of the emerging amphibian pathogens Batrachochytrium dendrobatidis and ranavirus in Russia.

    Reshetnikov, Andrey N; Chestnut, Tara; Brunner, Jesse L; Charles, Kaylene; Nebergall, Emily E; Olson, Deanna H

    2014-08-11

    In a population of the European common toad Bufo bufo from a rural pond in the region of Lake Glubokoe Regional Reserve in Moscow province, Russia, unexplained mass mortality events involving larvae and metamorphs have been observed over a monitoring period of >20 yr. We tested toads from this and a nearby site for the emerging amphibian pathogens Batrachochytrium dendrobatidis (Bd) and ranavirus (Rv). Both pathogens were detected, and at the rural pond site, with the above-noted losses and decline in toad breeding success, 40% of B. bufo metamorphs were Bd positive, 46% were Rv positive and 20% were co-infected with both pathogens. Toad metamorphs from a neighbouring water body were also Bd and Rv positive (25 and 55%, respectively). This is the first confirmation of these pathogens in Russia. Questions remain as to the origins of these pathogens in Russia and their roles in documented mass mortality events. PMID:25114047

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

    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.

  9. The complete mitochondrial genome of the color changeable toad-headed agama, Phrynocephalus versicolor (Reptilia, Squamata, Agamidae).

    Song, Sen; Li, Donghai; Zhang, Caihong; Jiang, Kaiju; Zhang, Dandan; Chang, Cheng

    2016-01-01

    The complete mitochondrial genome sequence of color changeable toad-headed agama, Phrynocephalus versicolor, was determined using polymerase chain reaction (PCR), long-and-accurate PCR and directly sequencing by primer walking. The entire mitochondrial genome of P. versicolor was 16,429 bp in length, the accession was KJ749841 and the content of A, T, C, and G were 36.1%, 26.5%, 24.9% and 12.5%, respectively, which was similar to most vertebrate. The complete mitochondrial genome of P. versicolor contain 13 protein-coding genes, 2 rRNA genes, 23 tRNA genes, plus one control region and was similar to those of other Phrynocephalus sand lizards in gene arrangement and composition, except that tRNA-Phe and tRNA-Pro were exchanged and tRNA-Phe had two copies. The control region comprised three parts, one between tRNA-Thr and tRNA-Phe, a second between tRNA-Pro and tRNA-Phe, and a third between tRNA-Phe and 12S RNA. The complete mitochondrial genome of P. versicolor provided fundamental data for resolving phylogenetic relationship problems related to Agaimidae and genus Phrynocephalus. PMID:24989048

  10. Multisensory signals trigger approach behaviour in the fire-bellied toad Bombina orientalis: sex differences and call specificity.

    Zeyl, Jeffrey N; Laberge, Frédéric

    2011-12-01

    Animal communication often involves multimodal signals, and interactions between sensory modalities can trigger unique responses in receivers. Response to social signals was investigated in fire-bellied toads by exposing them to playback of male calls (advertisement and release calls) and a video clip of a male conspecific in the laboratory. The cues were presented in isolation and as a combined bimodal stimulus, and approach frequency, latency to approach and time spent around the stimulus source were measured. No positive phonotaxis was observed toward the advertisement call, both during the day and during a phonotaxis trial performed at night. However, females, but not males, approached with greater frequency, lower latency, and spent more time near the source of the bimodal stimulus in an experiment involving the advertisement call. Female response was specific to the advertisement call, as approach was not increased when the release call was used. Males, on the other hand, did not show increased approach in the advertisement call experiment, but approached with greater frequency the bimodal stimulus involving the release call within the first minute of stimulus presentation. The findings suggest that females orient toward calling males and that males eavesdrop on release calls, but in both cases a visual stimulus is also needed to trigger a response. Social approach in Bombina orientalis is thus dependent on multisensory cues, and the nature of the interaction between sensory modalities depends on receiver sex and call type. PMID:21993061

  11. Development of 22 Polymorphic Microsatellite Loci for the Critically Endangered Morato’s Digger Toad, Proceratophrys moratoi

    Shirlei Maria Recco Pimentel

    2012-09-01

    Full Text Available The Morato’s digger toad (Proceratophrys moratoi inhabits Brazilian moist savannas and is critically endangered due to its very limited geographic distribution, reduced number of isolated populations, and evidence of population decline and local extinctions. With the objective of providing tools for the genetic study of the species, 22 polymorphic microsatellite loci were isolated and screened using DNA extracted from samples of oral mucosa cells obtained from 113 individuals representing five remnant P. moratoi populations in the Brazilian state of São Paulo. These markers presented 2–18 alleles per locus, polymorphism information content (PIC of 0.02–0.87, observed heterozygosity of 0.02–0.96 and expected heterozygosity of 0.02–0.87. Three of the loci deviated significantly from Hardy–Weinberg equilibrium in one of the populations, possibly due to the presence of null alleles. Significant linkage disequilibrium was also detected between three pairs of loci. The molecular markers developed in this study were able to discriminate each of the individuals sampled (identity analysis. This means that they will be extremely useful for future genetic studies applied to the conservation of P. moratoi, providing a baseline for estimating the levels of genetic diversity, pedigrees, inbreeding, and population structure, which will be essential for the development of effective genetic management programs.

  12. Genetic diversity and phylogeography of the Apennine yellow-bellied toad Bombina pachypus, with implications for conservation.

    Canestrelli, Daniele; Cimmaruta, Roberta; Costantini, Vera; Nascetti, Giuseppe

    2006-10-01

    Genetic variation was investigated in 17 populations of the Italian endemic Apennine yellow-bellied toad using both mitochondrial (598 bp of the cytochrome b gene) and nuclear (21 allozyme loci) markers. Populations from central Calabria (southern Italy) showed the highest levels of intrapopulation genetic variation, whereas samples located north of this region were nearly lacking in variation. This appears to be a typical pattern of 'southern richness and northern purity', usually attributed to the prolonged population stability within southern refugia coupled with the loss of variation during postglacial northward expansion. However, the overall pattern of genetic variation observed has a strong geographical component, suggesting two Calabrian plains, Catanzaro and Crati-Sibari, as historical barriers to dispersal separating three population groups. These findings cannot be explained by the prolonged stability of southern populations alone, and suggest that the southern richness has been at least in part shaped by allopatric differentiation within the refugial range, followed by intermixing of previously differentiated lineages. From a conservation standpoint, Calabria is the major genetic diversity reservoir for this species, thus deserving particular conservation efforts. Furthermore, although the low intrapopulation genetic variation outside Calabria appears to be of clear historical origin, evidence of a current reduction of gene flow suggests that human disturbance has also played a part, particularly in the anthropogenic impacted Volturno river drainage basin. PMID:17032271

  13. A comparison of human chorionic gonadotropin and luteinizing hormone releasing hormone on the induction of spermiation and amplexus in the American toad (Anaxyrus americanus

    Kouba Andrew J

    2012-08-01

    Full Text Available Abstract Background Captive breeding programs for endangered amphibian species often utilize exogenous hormones for species that are difficult to breed. The purpose of our study was to compare the efficacy of two different hormones at various concentrations on sperm production, quantity and quality over time in order to optimize assisted breeding. Methods Male American toads (Anaxyrus americanus were divided into three separate treatment groups, with animals in each group rotated through different concentrations of luteinizing hormone releasing hormone analog (LHRH; 0.1, 1.0, 4.0 and 32 micrograms/toad, human chorionic gonadotropin (hCG; 50, 100, 200, and 300 IU, or the control over 24 hours. We evaluated the number of males that respond by producing spermic urine, the sperm concentration, percent motility, and quality of forward progression. We also evaluated the effects of hCG and LHRH on reproductive behavior as assessed by amplexus. Data were analyzed using the Generalized Estimating Equations incorporating repeated measures over time and including the main effects of treatment and time, and the treatment by time interaction. Results The hormone hCG was significantly more effective at stimulating spermiation in male Anaxyrus americanus than LHRH and showed a dose-dependent response in the number of animals producing sperm. At the most effective hCG dose (300 IU, 100% of the male toads produced sperm, compared to only 35% for the best LHRH dose tested (4.0 micrograms. In addition to having a greater number of responders (P? Conclusion There is a clear dichotomy between the two hormones’ physiological responses on gamete production and stimulation of amplexus. Understanding how these two hormones influence physiology and reproductive behaviors in amphibians will have direct bearing on establishing similar breeding protocols for endangered species.

  14. Joint estimation of habitat dynamics and species interactions: disturbance reduces co-occurrence of non-native predators with an endangered toad

    Miller, David A.W.; Brehme, Cheryl S.; Hines, James E.; Nichols, James D.; Fisher, Robert N.

    2012-01-01

    1. Ecologists have long been interested in the processes that determine patterns of species occurrence and co-occurrence. Potential short-comings of many existing empirical approaches that address these questions include a reliance on patterns of occurrence at a single time point, failure to account properly for imperfect detection and treating the environment as a static variable. 2. We fit detection and non-detection data collected from repeat visits using a dynamic site occupancy model that simultaneously accounts for the temporal dynamics of a focal prey species, its predators and its habitat. Our objective was to determine how disturbance and species interactions affect the co-occurrence probabilities of an endangered toad and recently introduced non-native predators in stream breeding habitats. For this, we determined statistical support for alternative processes that could affect co-occurrence frequency in the system. 3. We collected occurrence data at stream segments in two watersheds where streams were largely ephemeral and one watershed dominated by perennial streams. Co-occurrence probabilities of toads with non-native predators were related to disturbance frequency, with low co-occurrence in the ephemeral watershed and high co-occurrence in the perennial watershed. This occurred because once predators were established at a site, they were rarely lost from the site except in cases when the site dried out. Once dry sites became suitable again, toads colonized them much more rapidly than predators, creating a period of predator-free space. 4. We attribute the dynamics to a storage effect, where toads persisting outside the stream environment during periods of drought rapidly colonized sites when they become suitable again. Our results support that even in highly connected stream networks, temporal disturbance can structure frequencies with which breeding amphibians encounter non-native predators. 5. Dynamic multi-state occupancy models are a powerful tool for rigorously examining hypotheses about inter-species and species-habitat interactions. In contrast to previous methods that infer dynamic processes based on static patterns in occupancy, the approach we took allows the dynamic processes that determine species-species and species-habitat interactions to be directly estimated.

  15. Joint estimation of habitat dynamics and species interactions: disturbance reduces co-occurrence of non-native predators with an endangered toad.

    Miller, David A W; Brehme, Cheryl S; Hines, James E; Nichols, James D; Fisher, Robert N

    2012-11-01

    1. Ecologists have long been interested in the processes that determine patterns of species occurrence and co-occurrence. Potential short-comings of many existing empirical approaches that address these questions include a reliance on patterns of occurrence at a single time point, failure to account properly for imperfect detection and treating the environment as a static variable. 2. We fit detection and non-detection data collected from repeat visits using a dynamic site occupancy model that simultaneously accounts for the temporal dynamics of a focal prey species, its predators and its habitat. Our objective was to determine how disturbance and species interactions affect the co-occurrence probabilities of an endangered toad and recently introduced non-native predators in stream breeding habitats. For this, we determined statistical support for alternative processes that could affect co-occurrence frequency in the system. 3. We collected occurrence data at stream segments in two watersheds where streams were largely ephemeral and one watershed dominated by perennial streams. Co-occurrence probabilities of toads with non-native predators were related to disturbance frequency, with low co-occurrence in the ephemeral watershed and high co-occurrence in the perennial watershed. This occurred because once predators were established at a site, they were rarely lost from the site except in cases when the site dried out. Once dry sites became suitable again, toads colonized them much more rapidly than predators, creating a period of predator-free space. 4. We attribute the dynamics to a storage effect, where toads persisting outside the stream environment during periods of drought rapidly colonized sites when they become suitable again. Our results support that even in highly connected stream networks, temporal disturbance can structure frequencies with which breeding amphibians encounter non-native predators. 5. Dynamic multi-state occupancy models are a powerful tool for rigorously examining hypotheses about inter-species and species-habitat interactions. In contrast to previous methods that infer dynamic processes based on static patterns in occupancy, the approach we took allows the dynamic processes that determine species-species and species-habitat interactions to be directly estimated. PMID:22702337

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

    Maria Mastrodonato; Roberta Rossi; Angela Maria Moramarco; Giovanni Scillitani

    2011-01-01

    We studied the glycopatterns and ultrastructure of the extra-cellular matrix (ECM) of the egg of the Apennine 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 Alcian Blue 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...

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

    Giovanni Scillitani; Angela Maria Moramarco; Roberta Rossi; Maria Mastrodonato

    2011-01-01

    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 ...

  18. Light regulation of cGMP metabolism in toad rod outer segments (ROS) deduced from intact photoreceptor and cellfree kinetics

    The rate of cGMP hydrolysis by phosphodiesterase (PDE) in intact ROS, monitored in dark-adapted isolated toad retina by the rate of 18O appearance in guanine nucleotide ?-phosphoryls, is 1/360th of that observed in disrupted ROS at a substrate concentration equivalent to the total [cGMP] in ROS. Low to moderate photic stimuli increase this cGMP hydrolytic rate up to 10-fold in intact ROS with little or no change in total [cGMP]. G-protein activation determined in intact ROS by the fraction of GDP labeled with 18O corresponds with light-related increases in cGMP flux. In contrast, relatively high intensities and extended illumination cause attenuation of maximal cGMP hydrolysis with proportionate reductions in total [cGMP]. From these observations combined with the effects of activated G-protein on kinetics and cGMP binding of ROS PDE the following model for light-regulation of cGMP metabolism was deduced: cGMP flux in intact ROS is severely restricted in the dark state because approximately 99% of the cGMP is bound to high affinity sites on the non-stimulated form of PDE. This constraint is relieved when activated G-protein converts the cGMP-binding form of PDE to a high K/sub m/ catalytic form. cGMP is then redistributed to a dynamic pool where it is available to PDE catalytic sites and lower affinity allosteric sites. The [cGMP] in the dynamic pool is maintained or further increased or decreased by modulating the activity of an apparently light-sensitive guanylyl cyclase

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

    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 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

  20. Survey of helminths, ectoparasites, and chytrid fungus of an introduced population of cane toads, Rhinella marina (Anura: Bufonidae), from Grenada, West Indies.

    Drake, Michael C; Zieger, Ulrike; Groszkowski, Andrew; Gallardo, Bruce; Sages, Patti; Reavis, Roslyn; Faircloth, Leslie; Jacobson, Krystin; Lonce, Nicholas; Pinckney, Rhonda; Cole, Rebecca A

    2014-10-01

    One hundred specimens of Rhinella marina , (Anura: Bufonidae) collected in St. George's parish, Grenada, from September 2010 to August 2011, were examined for the presence of ectoparasites and helminths. Ninety-five (95%) were parasitized by 1 or more parasite species. Nine species of parasites were found: 1 digenean, 2 acanthocephalans, 4 nematodes, 1 arthropod and 1 pentastome. The endoparasites represented 98.9% of the total number of parasite specimens collected. Grenada represents a new locality record for Mesocoelium monas, Raillietiella frenatus, Pseudoacanthacephalus sp., Aplectana sp., Physocephalus sp., Acanthacephala cystacanth, and Physalopteridae larvae. The digenean M. monas occurred with the highest prevalence of 82%, contrasting many studies of R. marina where nematodes dominate the parasite infracommunity. Female toads were found to have a significantly higher prevalence of Amblyomma dissimile than male toads. Only 2 parasites exhibited a significant difference between wet and dry season with Parapharyngodon grenadensis prevalence highest in the wet season and A. dissimile prevalence highest during the dry season. Additionally, A. dissimile was significantly more abundant during the dry season. PMID:24960037

  1. Outcrop analysis of trace fossil assemblages in the Toad Formation (Triassic), SE Yukon Territory : implications for hydrocarbon exploration in NE British Columbia

    MacNaughton, R.B.; Zonneveld, J.P.; Utting, J. [Geological Survey of Canada, Calgary, AB (Canada)

    2002-07-01

    Hydrocarbon producing strata is often characterized by trace fossil assemblages, but trace fossils are not always available for core-based sub surfaces. Therefore, it is a good idea to integrate outcrop and subsurface ichnological studies to make better use of subsurface data. Strata of the Lower Triassic Toad Formation in the southeastern region of the Yukon Territory consists of inter bedded shale, siltstone, and sandstone. The rocks contain a diverse assemblage of well-preserved trace fossils. Five facies associations have been recognized within the stratigraphic sequence. They reveal that the rocks were deposited on a wave-dominated shelf. In distal shelf facies, the trace fossil diversity is low, but is moderate to high in offshore to shoreface strata. The most common ichno fossils are burrow networks and simple infaunal burrows. Arthropods make up much of the ichno fauna. It was noted that the sediments and trace fossil assemblages of the Toad Formation in the La Biche River area are similar to the gas producing strata of the Montney Formation of northeastern British Columbia. The Yukon succession can potentially be used to model that of British Columbia.

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

    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.

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

    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.

  4. Antimicrobial peptides and alytesin are co-secreted from the venom of the Midwife toad, Alytes maurus (Alytidae, Anura): implications for the evolution of frog skin defensive secretions.

    König, Enrico; Zhou, Mei; Wang, Lei; Chen, Tianbao; Bininda-Emonds, Olaf R P; Shaw, Chris

    2012-11-01

    The skin secretions of frogs and toads (Anura) have long been a known source of a vast abundance of bioactive substances. In the past decade, transcriptome data of the granular glands of anuran skin has given new impetus to investigations of the putative constituent peptides. Alytes obstetricans was recently investigated and novel peptides with antimicrobial activity were isolated and functionally characterised. However, genetic data for the evolutionarily ancient lineage to which Alytes belongs (midwife toads; Alytidae) remains unavailable. Here we present the first such genetic data for Alytidae, derived via the granular gland transcriptome of a closely-related species of midwife toad, Alytes maurus. First, we present nucleotide sequences of the entire peptide precursors for four novel antimicrobial peptides (AMPs). The two precursors resemble those from Bombinatoridae in both their structural architecture and amino acid sequence. Each precursor comprises two AMPs as tandem repeats, with a member of the alyteserin-1 family (alyteserin-1Ma: GFKEVLKADLGSLVKGIAAHVAN-NH2 or alyteserin-1Mb: GFKEVLKAGLGSLVKGIPAHVAN-NH2) followed by its corresponding member from the alyteserin-2 family (alyteserin-2Ma: FIGKLISAASGLLSHL-NH2 or alyteserin-2Mb: ILGAIIPLVSGLLSHL-NH2). Synthetic replicates of the four AMPs possessed minimal inhibitory concentrations (MICs) ranging from 9.5 to 300 μM, with the most potent being alyteserin-2Ma. Second, we also cloned the cDNA encoding an alytesin precursor, with the active alytesin exhibiting high sequence identity to bombesin-related peptides from other frogs. All putative mature peptide sequences were confirmed to be present in the skin secretion via LC/MS. The close structural resemblance of the alyteserin genes that we isolated for A. maurus with those of Bombina provide independent molecular evidence for a close evolutionary relationship between these genera as well as more support for the convergent evolution of the AMP system within anurans. In contrast to the more evolutionarily conserved nature of neuropeptides (including alytesin, which we also isolated), the more variable nature of the AMP system together with the sporadic distribution of AMPs among anuran amphibians fuels in part our hypothesis that the latter system was co-opted secondarily to fulfil a function in the innate immune system, having originally evolved for defence against potential macropredators. PMID:22800568

  5. The complete mitochondrial genome of the subspecies, Phrynocephalus erythrurus parva (Reptilia, Squamata, Agamidae), a toad-headed lizard dwell at highest elevations of any reptile in the world.

    Zhu, Liufang; Liao, Pinghu; Tong, Haojie; Jin, Yuanting

    2016-01-01

    The complete mitochondrial genome was sequenced from the toad-headed viviparous lizard subspecies, Phrynocephalus erythrurus parva, which occupies the highest regions of any reptile on the earth. The mitogenome sequence was 16,431 bp in size, with the overall base composition of H-strand is T: 26.06%, C: 25.14%, A: 36.45%, G: 12.35%. It consists of 13 protein coding, 22 tRNA, 2 rRNA genes and 3 control regions, and its gene order and gene content were identical with the published congeneric mitogenomes of other Phrynocephalus, except for the small protion between tRNA-Pro and tRNA-Phe. PMID:24810070

  6. Peptide IC-20, encoded by skin kininogen-1 of the European yellow-bellied toad, Bombina variegata, antagonizes bradykinin-induced arterial smooth muscle relaxation

    Mu Yang

    2011-01-01

    Full Text Available Objectives: The objectives were to determine if the skin secretion of the European yellow-bellied toad (Bombina variegata, in common with other related species, contains a bradykinin inhibitor peptide and to isolate and structurally characterize this peptide. Materials and Methods: Lyophilized skin secretion obtained from this toad was subjected to reverse phase HPLC fractionation with subsequent bioassay of fractions for antagonism of the bradykinin activity using an isolated rat tail artery smooth muscle preparation. Subsequently, the primary structure of the peptide was established by a combination of microsequencing, mass spectroscopy, and molecular cloning, following which a synthetic replicate was chemically synthesised for bioassay. Results: A single peptide of molecular mass 2300.92 Da was resolved in HPLC fractions of skin secretion and its primary structure determined as IYNAIWP-KH-NK-KPGLL-. Database interrogation with this sequence indicated that this peptide was encoded by skin kininogen-1 previously cloned from B. variegata. The blank cycles were occupied by cysteinyl (C residues and the peptide was located toward the C-terminus of the skin kininogen, and flanked N-terminally by a classical -KR- propeptide convertase processing site. The peptide was named IC-20 in accordance (I = N-terminal isoleucine, C = C-terminal cysteine, 20 = number of residues. Like the natural peptide, its synthetic replicate displayed an antagonism of bradykinin-induced arterial smooth muscle relaxation. Conclusion: IC-20 represents a novel bradykinin antagonizing peptide from amphibian skin secretions and is the third such peptide found to be co-encoded with bradykinins within skin kininogens.

  7. Mixed Sex Effects on the Second-to-Fourth Digit Ratio of Túngara Frogs (Engystomops pustulosus) and Cane Toads (Rhinella marina).

    Beaty, Lynne E; Emmering, Quinn C; Bernal, Ximena E

    2016-04-01

    Sexual dimorphism in the ratio of digit lengths has been correlated to behavioral, physiological, and morphological traits in a variety of taxa. While sexual dimorphism in the second-to-fourth digit length ratio (2D:4D) is a well-established indicator of prenatal androgen exposure in mammals, investigations into the patterns of 2D:4D and the drivers of such variation in other taxa are lacking. We used linear mixed effects models to gain a mechanistic understanding of the factors that drive variation in the scaling relationship between the lengths of the second and fourth digits in two species of anurans: túngara frogs (Engystomops pustulosus) and cane toads (Rhinella marina). We found evidence for sexual dimorphism of the 2D:4D scaling relationship on the front feet of túngara frogs, with female frogs having a larger ratio than males resulting from a relatively longer second digit on females. To our knowledge, this mammal-like pattern of sex differences in digit ratio has not yet been reported for anurans. However, given the reduced number of digits on the front feet of anurans, and uncertainty about which digit was lost during evolutionary history, this apparent sexual dimorphism in the front feet of túngara frogs should be treated with caution. In contrast, we found no evidence of sexual dimorphism in 2D:4D on either the front or rear feet of cane toads. This study highlights ambiguities in 2D:4D across taxa and suggests that further research is needed to evaluate the effect of androgens on 2D:4D in animals other than placental mammals. Anat Rec, 299:421-427, 2016. © 2016 Wiley Periodicals, Inc. PMID:26815928

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

    Macías, Guadalupe; Marco, Adolfo; Blaustein, Andrew R.

    2007-01-01

    Many aquatic species are sensitive to ambient levels of ultraviolet-B radiation (UVB) and chemical fertilizers. However, recent studies indicate that the interaction among multiple stressors acting simultaneously could be contributing to the population declines of some animal species. Therefore, we tested the potential synergistic effects between ambient levels of UVB and a contaminant, sodium nitrite in the larvae of two amphibian species, the common European toad Bufo bufo and the Iberian g...

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

    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.

  10. Novel cytosolic binding partners of the neural cell adhesion molecule: mapping the binding domains of PLC gamma, LANP, TOAD-64, syndapin, PP1, and PP2A.

    Büttner, Bettina; Kannicht, Christoph; Reutter, Werner; Horstkorte, Rüdiger

    2005-05-10

    The neural cell adhesion molecule (NCAM) is implicated in important functions during development and maintenance of the nervous system. Two of the three major isoforms, NCAM 140 and NCAM 180, are transmembrane glycoproteins with large cytoplasmic domains of different length. The purpose of this study was to identify novel intracellular binding partners of NCAM 140 and NCAM 180. We expressed both cytoplasmic domains, as well as cytoplasmic fragments of NCAM, as fusion proteins in Escherichia coli and used them for ligand affinity chromatography or glutathione S-transferase (GST) pull-down assays. By peptide mass fingerprinting Western blot analysis, or both, we identified PLCgamma, LANP, syndapin, PP1, and PP2A as binding partners for both NCAM 140 and NCAM 180, whereas TOAD-64 was identified as a NCAM 180-specific interacting protein. Furthermore, we were able to show that binding of these novel binding proteins, as well as the previously described interaction partners ROK alpha (rho A binding kinase alpha) and alpha- and beta-tubulin, bind to specific cytosolic sequences of NCAM. For this purpose, we performed GST pull-down experiments using cytosolic fragments of NCAM as GST-fusion proteins and cytosolic- or cytoskeleton-enriched protein fractions of rat brain. PMID:15865439

  11. Influence of geology and human activity on the genetic structure and demography of the Oriental fire-bellied toad (Bombina orientalis).

    Fong, Jonathan J; Li, Pi-Peng; Yang, Bao-Tian; Zhou, Zheng-Yan; Leaché, Adam D; Min, Mi-Sook; Waldman, Bruce

    2016-04-01

    The Oriental fire-bellied toad (Bombina orientalis) is a commonly used study organism, but knowledge of its evolutionary history is incomplete. We analyze sequence data from four genetic markers (mtDNA genes encoding cytochrome c oxidase subunit I, cytochrome b, and 12S-16S rRNA; nuDNA gene encoding recombination activating gene 2) from 188 individuals across its range in Northeast Asia to elucidate phylogeographic patterns and to identify the historic events that shaped its evolutionary history. Although morphologically similar across its range, B. orientalis exhibits phylogeographic structure, which we infer was shaped by geologic, climatic, and anthropogenic events. Phylogenetic and divergence-dating analyses recover four genetically distinct groups of B. orientalis: Lineage 1-Shandong Province and Beijing (China); Lineage 2-Bukhan Mountain (Korea); Lineage 3-Russia, Northeast China, and northern South Korea; and Lineage 4-South Korea. Lineage 2 was previously unknown. Additionally, we discover an area of secondary contact on the Korean Peninsula, and infer a single dispersal event as the origin of the insular Jeju population. Skyline plots estimate different population histories for the four lineages: Lineages 1 and 2 experienced population decreases, Lineage 3 remained stable, while Lineage 4 experienced a sharp increase during the Holocene. The timing of the population expansion of Lineage 4 coincides with the advent of rice cultivation, which may have facilitated the increase in population size by providing additional breeding habitat. PMID:26748269

  12. Assessment of interactive effects of elevated salinity and three pesticides on life history and behavior of southern toad (Anaxyrus terrestris) tadpoles.

    Wood, Liza; Welch, Allison M

    2015-03-01

    Because habitats are increasingly exposed to multiple stressors simultaneously, assessing the interactive effects of stressors is crucial for understanding how populations respond to human-altered habitats. Salinization of freshwater habitats is increasing and has the potential to interact with other stressors. Chemical pollutants also contribute to habitat degradation in freshwater environments, and both salinity and various pesticides can harm amphibians. The present study used a factorial experiment to investigate the effect of elevated salinity alone and in combination with each of 3 pesticides-atrazine, carbaryl, and glyphosate-on life history and behavior of southern toad larvae (Anaxyrus terrestris). Tadpoles were negatively affected by elevated salinity and by exposure to the insecticide carbaryl, with the most deleterious outcomes associated with both stressors combined. Carbaryl exposure led to reduced survival as well as sublethal effects on growth, activity and feeding behavior, escape response swimming, and time to metamorphosis. Tadpoles reared at elevated salinity were also smaller and less active, and ultimately metamorphosed later and at smaller size. Together, carbaryl and elevated salinity had a synergistic effect, resulting in particularly poor growth, depressed activity and feeding, and sluggish escape swimming among tadpoles exposed to both stressors simultaneously. These results suggest that both elevated salinity and carbaryl represent threats for amphibian populations and that pesticide exposure in salinized habitats may pose a particularly high risk. PMID:25523942

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

    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...... 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 m......M 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...

  14. Chemical skin defence in the Eastern fire-bellied toad Bombina orientalis: an ultrastructural approach to the mechanism of poison gland rehabilitation after discharge

    Sara Quagliata

    2008-12-01

    Full Text Available Type I serous glands in the skin of the Eastern yellow-bellied toad Bombina orientalis released their product massively after 10-3 M nor-adrenalin (NA stimulation, mimicking orthosympathetic control on poison emission in chemical skin defence. Features of cutaneous glands involved in this bulk discharge were observed under light and electron microscopes. Furthermore, restoration of depleted glands was followed after 1, 2 and 3 weeks, and compared with serous biosynthesis during larval gland development. Bulk discharge was caused by contraction of myoepithelial cells (mecs encircling the secretory units. Mec compression dramatically affected the secretory unit, but parts of this syncytial cytoplasm were saved from degeneration and cooperated in gland renewal with stem cells from the gland neck. These adenoblasts underwent proliferation and secretory cytodifferentiation, until merging with the syncytium. Cytoplasm that had resumed secretory activity showed the features typical of larval gland development: the endoplasmic reticulum (rer cisterns were aligned in close parallel arrangement and Golgi stacks released minute type I granules. Secretory rehabilitation led to increasing amounts of granule content. In the meantime, rough cisterns decreased in number and assumed the less ordered pattern described in control specimens. Data collected in the present study revealed that chemical skin defence in anurans is a multi-factorial mechanism involving specific activities: mechanical from mecs, biosynthetic from secretory syncytium and proliferative from intercalated stem cells.

  15. 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

    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.

  16. Records of Sandflies (Diptera: Psychodidae: Phlebotominae feeding on Amphibia, with A new record from the Kruger National Park

    H. H Braack

    1981-01-01

    Full Text Available An early record of a sandfly feeding on an amphibian is that of Hewlett (1913, Indian J. med. Res. 1: 34-38 who wrote "I have twice seen a sandfly apparently biting the head of the common toad Bufo melanostictus".

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

    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

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

    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 α and β 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 γ/ photocrosslinked with PDE/sub α/ or PDE/sub β/, respectively. cGMP prebound to these high affinity sites was released by light-activated G-protein or its α subunit complexed with GTPγS; 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-dependent membrane cation channels

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

    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.

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

    Scillitani, Giovanni; Moramarco, Angela Maria; Rossi, Roberta; Mastrodonato, Maria

    2011-01-01

    We studied the glycopatterns and ultrastructure of the extra-cellular matrix (ECM) of the egg of the Apennine 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 Alcian Blue pH 2.5 and 1.0, performed also after β-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 were O-linked, with many glucosamylated and fucosylated residues. The fertilization envelope presented a perivitelline space 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 J(1) and J(4) layers, whereas a looser arrangement was observed in the other layers. Jelly-layer glycans were mostly acidic and particularly abundant in the J(1) and J(4) layers. In the J(1), J(2) and J(5) layers, neutral, N-linked glycans were also observed. Mannosylated and/or glucosylated as well as galactosyl/galactosaminylated residues were more abundant in the outer layers. Many microorganisms were observed in the J(5) layer. We believe that, apart from their functions in the fertilization process, acidic and fucosylated glycans could act as a barrier against pathogen penetration. PMID:21744333

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

    Maria Mastrodonato

    2011-07-01

    Full Text Available We studied the glycopatterns and ultrastructure of the extra-cellular matrix (ECM of the egg of the Apennine 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 Alcian Blue 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 were O-linked, with many glucosamylated and fucosylated residues. The fertilization envelope presented a perivitelline space 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 particularly abundant 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 the outer layers. Many microorganisms were observed in the J5 layer. We believe that, apart from their functions in the fertilization process, acidic and fucosylated glycans could act as a barrier against pathogen penetration. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 2, pp. 306–316

  2. Blood lead levels, δ-ALAD inhibition, and hemoglobin content in blood of giant toad (Rhinella marina) to assess lead exposure in three areas surrounding an industrial complex in Coatzacoalcos, Veracruz, Mexico.

    Ilizaliturri-Hernández, César Arturo; González-Mille, Donaji Josefina; Mejía-Saavedra, Jesús; Espinosa-Reyes, Guillermo; Torres-Dosal, Arturo; Pérez-Maldonado, Iván

    2013-02-01

    The Coatzacoalcos Region in Veracruz, Mexico houses one of the most important industrial complexes in Mexico and Latin America. Lead is an ubiquitous environmental pollutant which represents a great risk to human health and ecosystems. Amphibian populations have been recognized as biomonitors of changes in environmental conditions. The purpose of this research is to measure exposure to lead and evaluate hematological and biochemical effects in specimens of giant toads (Rhinella marina) taken from three areas surrounding an industrial complex in the Coatzacoalcos River downstream. Lead levels in toads' blood are between 10.8 and 70.6 μg/dL and are significantly higher in industrial sites. We have found a significant decrease in the delta-aminolevulinic acid dehydratase (δ-ALAD) activity in blood from 35.3 to 78 % for the urban-industrial and industrial sites, respectively. In addition, we have identified a strong inverse relationship between the δ-ALAD activity and the blood lead levels (r = -0.84, p ALAD activity inhibition and hematological alterations at low lead concentrations. PMID:22580791

  3. Estimating Effects of Species Interactions on Populations of Endangered Species.

    Roth, Tobias; Bühler, Christoph; Amrhein, Valentin

    2016-04-01

    Global change causes community composition to change considerably through time, with ever-new combinations of interacting species. To study the consequences of newly established species interactions, one available source of data could be observational surveys from biodiversity monitoring. However, approaches using observational data would need to account for niche differences between species and for imperfect detection of individuals. To estimate population sizes of interacting species, we extended N-mixture models that were developed to estimate true population sizes in single species. Simulations revealed that our model is able to disentangle direct effects of dominant on subordinate species from indirect effects of dominant species on detection probability of subordinate species. For illustration, we applied our model to data from a Swiss amphibian monitoring program and showed that sizes of expanding water frog populations were negatively related to population sizes of endangered yellow-bellied toads and common midwife toads and partly of natterjack toads. Unlike other studies that analyzed presence and absence of species, our model suggests that the spread of water frogs in Central Europe is one of the reasons for the decline of endangered toad species. Thus, studying population impacts of dominant species on population sizes of endangered species using data from biodiversity monitoring programs should help to inform conservation policy and to decide whether competing species should be subject to population management. PMID:27028074

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

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

    2011-01-01

    Amphibians highlight the global biodiversity crisis because ∼40% of all amphibian species are currently in decline. Species have disappeared even in protected habitats (e.g., the enigmatic extinction of the golden toad, Bufo periglenes, from Costa Rica). The emergence of a fungal pathogen, Batrachochytrium dendrobatidis (Bd), has been implicated in a number of declines that have occurred in the last decade, but few studies have been able to test retroactively whether Bd emergence was linked t...

  5. Respiration and carbohydrate energy metabolism of the lung-dwelling parasite Rhabdias bufonis (Nematoda: Rhabdiasoidea).

    Anya, A O; Umezurike, G M

    1978-02-01

    An investigation of the carbohydrate energy metabolism of Rhabdias bufonis, the lung-dwelling nematode parasite of the African toad, Bufo regularis, indicates that the nematode stores very little glycogen (0.137 +/- 0.003% on a fresh weight basis) but does utilize oxygen in vitro. The intracellular distribution and high levels of activity observed for the enzymes phosphoenolpyruvate carboxykinase, pyruvate kinase, lactate dehydrogenase, malate dehydrogenase, malic enzyme and fumarate reductase suggest two alternative pathways of carbohydrate energy metabolism. PMID:564016

  6. Monitoring programs to assess reintroduction efforts: a critical component in recovery

    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 baxteri) as an example. Using an iterative process, existing data is built upon gradually such that demographic estimates and subsequent infere...

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

    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...

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

    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...

  9. Nematodes of amphibians from Java, Indonesia, with a description of new species, Meteterakis wonosoboensis n. sp. (Nematoda : Heterakoidea).

    Purwaningsih, Endang; Dewi, Kartika; Hasegawa, Hideo

    2015-01-01

    During a survey on the parasites of amphibians of Indonesia, toads (30 Bufo melanostictus) and 246 frogs (213 Fejervarya cancrivora, 11 F. limnocharis, 22 Rana macrodon from West Java and 68 F. cancrivora from Central Java) were examined for parasitic nematodes. Three species of nematodes were found and described, i.e. Meteterakis wonosoboensis n. sp. from Fejervaria cancrivora; Meteterakis japonica from Bufo melanostictus, F. cancrivora and F. limnocharis; and Chabaudus sp. from F. cancrivora, F. limnocharis and Rana macrodon. Meteterakis wonosoboensis n. sp. is distinguished from other species of the genus by the length and shape of spicules, the number of caudal papillae, the presence of gubernaculum in male and the presence of vulval flap in female. Bufo melanostictus and Java are recorded as new host and locality for M. japonica, respectively. PMID:26249921

  10. Toads Give You Warts--Not!

    Tomasek, Terry; Matthews, Catherine E.

    2008-01-01

    The authors provide activities through which teachers can share experiences in the outdoors with young children and teach them about herpetology, the study of amphibians and reptiles. Outdoor activities include observation, classification, and mapping. The authors also include activities for the classroom, including connections between the science…

  11. Arroyo Toad Range - CWHR [ds612

    California Department of Resources — Vector datasets of CWHR range maps are one component of California Wildlife Habitat Relationships (CWHR), a comprehensive information system and predictive model...

  12. Sink or swim: a test of tadpole behavioral responses to predator cues and potential alarm pheromones from skin secretions.

    Maag, Nino; Gehrer, Lukas; Woodhams, Douglas C

    2012-11-01

    Chemical signaling is a vital mode of communication for most organisms, including larval amphibians. However, few studies have determined the identity or source of chemical compounds signaling amphibian defensive behaviors, in particular, whether alarm pheromones can be actively secreted from tadpoles signaling danger to conspecifics. Here we exposed tadpoles of the common toad Bufo bufo and common frog Rana temporaria to known cues signaling predation risk and to potential alarm pheromones. In both species, an immediate reduction in swimming activity extending over an hour was caused by chemical cues from the predator Aeshna cyanea (dragonfly larvae) that had been feeding on conspecific tadpoles. However, B. bufo tadpoles did not detectably alter their behavior upon exposure to potential alarm pheromones, neither to their own skin secretions, nor to the abundant predator-defense peptide bradykinin. Thus, chemicals signaling active predation had a stronger effect than general alarm secretions of other common toad tadpoles. This species may invest in a defensive strategy alternative to communication by alarm pheromones, given that Bufonidae are toxic to some predators and not known to produce defensive skin peptides. Comparative behavioral physiology of amphibian alarm responses may elucidate functional trade-offs in pheromone production and the evolution of chemical communication. PMID:22972229

  13. Proton pump activity is required for active uptake of chloride in isolated amphibian skin exposed to freshwater

    Jensen, Lars Jørn; Willumsen, Niels J.; Larsen, Erik Hviid

    2002-01-01

    Net proton secretion and unidirectional chloride fluxes were measured in isolated skin of toads (Bufo bufo) and frogs (Rana esculenta) mounted in an Ussing chamber and exposed to a Ringer's solution on the serosal side and a freshwater-like solution (1-3 mM Cl-) on the external side. Active proto...... active Cl- uptake in fresh water by creating a favourable gradient for an apical HCO3- exit in exchange for external Cl-. The data also suggest that a carbonic anhydrase activity provides H+ and HCO3- for apically co-expressed proton pumps and Cl-/HCO3- exchangers....... rheogenic proton pump. Cl- influx was 37.4-7.5 pmol·cm-2·s-1 (n=14) in frog skin and 19.5-3.5 pmol·cm-2·s-1 (n=11) in toad skin. In toad skin, the mean Cl- flux ratio was larger than expected for simple electro-diffusion. In 8 of 11 sets of paired skins, influx was greater than the efflux indicating active......-type proton pump (V-ATPase) inhibitor, significantly reduced proton secretion in frog skin. In addition, concanamycin A (1 µM) significantly reduced Cl- influx in frog skin. We suggest that the active proton secretion and Cl- influx are coupled. We hypothesise that an apical V-ATPase is capable of energising...

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

    Weber, Roy E.

    2014-01-01

    )) 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...... 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....

  15. Surfaces of rod photoreceptor disk membranes: integral membrane components

    1982-01-01

    The membrane surfaces within the rod outer segment of the toad, Bufo marinus, were exposed by rapid-freezing followed by freeze-fracture and deep-etching. Platinum-carbon replicas of disk membranes prepared in this way demonstrate a distinct sidedness. The membrane surface that faces the lumen of the disk shows a fine granularity; particles of approximately 6 nm are packed at a density of approximately 30,000/micron 2. These dimensions suggest that the particles represent protrusions of the i...

  16. Homeotic regeneration of eye in amphibian tadpoles and its enhancement by vitamin A

    O P Jangir; D V S Shekhawat; Acharya Prakash; K K Swami; Pawan Suthar

    2001-12-01

    After removal of both the lateral eyes of external gill stage tadpoles of the toad Bufo melanostictus, the pineal organ gets transformed into a median eye. This type of transformation occurrs in tadpoles of both control and vitamin A treated groups. However, vitamin A increases the likelihood of homeotic regeneration (57% in the control group and 71% in the vitamin A treated group). Histological studies showed that the newly transformed median eye developed from the pineal organ. The pineal eye so developed possessed all components of a normal eye such as a retina, sensory cells and lens.

  17. The use of cytoenzymological changes in certain parasitic protozoans for screening the carcinogenicity of chemicals.

    el-Mofty, M M; Abdelmeguid, N; Michael, A E; el-Marhoumi, K M

    1989-01-01

    Cytoenzymological changes were observed in parasitic ciliates (Nyctotheroides puytoraci) and flagellates (Opalina sudafricana and Protoopalina sp.) after injection of their host, Bufo regularis, with a single dose of 0.5 mg beta-naphthylamine (BNA) per toad. The experiment was carried out during the host's pre-breeding season. Trophozoites of the given parasites were examined 21 days after the injection. The localization of the mitochondria and the relative intensity of succinic dehydrogenase (SDH) and deoxyribonucleic acid (DNA) activity in the control and BNA-treated trophozoites were compared. The results could prove useful for screening the carcinogenicity of chemicals by means of these parasitic protozoans. PMID:2759500

  18. Amphibians and disease: Implications for conservation in the Greater Yellowstone Ecosystem

    Corn, P.S.

    2007-01-01

    The decline of amphibian populations is a world-wide phenomenon that has received increasing attention since about 1990. In 2004, the World Conservation Union’s global amphibian assessment concluded that 48% of the world’s 5,743 described amphibian species were in decline, with 32% considered threatened (Stuart et al. 2004). Amphibian declines are a significant issue in the western United States, where all native species of frogs in the genus Rana and many toads in the genus Bufo are at risk, particularly those that inhabit mountainous areas (Corn 2003a,b; Bradford 2005).

  19. Studies of Annual and Seasonal Variations in Four Species of Reptiles and Amphibians at Los Alamos National Laboratory

    Keller, D.C.; Nelson, E.I.; Mullen, M.A.; Foxx, T.S.; Haarmann, T.K.

    1998-07-01

    Baseline studies of reptiles and amphibians of the Pajarito wetlands at Los Alamos National Laboratory have been conducted by the Ecology group since 1990. With the data gathered from 1990-1997 (excluding 1992), we examined the annual and seasonal population changes of four species of reptiles and amphibians over the past seven years. The four species studied are the Woodhouse toad (Bufo woodhousii), the western chorus frog (Pseudacris triseriata), the many-lined skink (Eunzeces nudtivirgatus), and the plateau striped whiptail lizard (Cnemidophorus velox). Statistical analyses indicate a significant change on a seasonal basis for the western chorus frog and the many-lined skink. Results indicate a significant difference in the annual population of the Woodhouse toad.

  20. Uranium content in the blood of some vertebrates

    Das, K.C.; Hanifa, A.; Goswami, T.D.

    1986-01-01

    The method of fission track analysis has been used to estimate the uranium concentration in the blood of some vertebrates like lata fish (Ophiocephalus punctatus - class Pisces), toad (Bufo melanostictus -class Amphibia) and man (Homo Sapiens - class Mammalia). The uranium content in the blood of these vertebrates has been found to range from 0.20 +- 0.016 to 0.94 +- 0.038 microgram/litre. However, the concentration in toad is found to be the lowest (0.20 +- 0.016 to 0.40 +- 0.022 microgram/litre) as compared to that in fish (0.50 +- 0.027 to 0.94 +- 0.038 microgram/litre) and man (0.33 +- 0.023 to 0.74 +- 0.034 microgram/litre). The intervariation among the different classes of vertebrates as regards uranium concentration has been found to be statistically significant.

  1. Differential processing of provasotocin: relative increase of hydrin 2 (vasotocinyl-Gly) in amphibians able to adapt to an arid environment.

    Michel, G; Ouedraogo, Y; Chauvet, J; Katz, U; Acher, R

    1993-08-01

    Hydrin 2 (vasotocinyl-Gly) is an intermediate in pro-vasotocin processing found, along with vasotocin, only in the neurohypophysis of anuran amphibians. It increases cutaneous water permeability in the frog and is likely involved in neuroendocrine control of osmoregulation. The relative amounts of vasotocin and hydrin 2 stored in neurohypophysis have been measured on the one hand in amphibian species known not to adapt in dry areas, on the other hand in two species, Bufo regularis (Africa) and Bufo viridis (Near-East) able to survive in an arid environment. In the first group, the proportions of the two peptides are approximately equal whereas in the two toads the molar ratio hydrin 2 to vasotocin reaches 2. The ratio does not appear to vary significantly when these toads are either submitted to dehydration or placed in saline solutions. Predominance of hydrin 2 suggests an adaptive decrease of the activity of the alpha-amidating enzymatic system involved in the conversion of vasotocinyl-Gly into mature amidated vasotocin. PMID:8413858

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

    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.

  3. A miniature microdrive for recording auditory evoked potentials from awake anurans.

    Mohammed, Haitham S; Radwan, Nasr M; Walkowiak, Wolfgang; Elsayed, Anwar A

    2013-09-01

    Electrical activity recording from the brains of awake animals is a corner stone in the study of the neurophysiological basis of behavior. To meet this need, a microelectrode driver suitable for the animal of interest has to be developed. In the present study a miniature microdrive was developed specifically for the leopard toad, Bufo regularis, however, it can be used for other small animals. The microdrive was designed to meet the following requirements: small size, light weight, simple and easy way of attaching and removing, advancing and withdrawing of microelectrode in the animal brain without rotation, can be reused and made from inexpensive materials. To assess the performance of the developed microdrive, we recorded auditory evoked potentials from different auditory centers in the toad's brain. The potentials were obtained from mesencephalic, diencephalic and telencephalic auditory sensitive areas in response to simple and complex acoustic stimuli. The synthetic acoustical tones introduced to the toad were carrying the dominant frequencies of their mating calls. PMID:23817637

  4. The activity of superoxide dismutase in animal liver and erythrocyte at Sea Area nearby Dayawan Nuclear Power Station

    Many tests, the effect of ionizing radiation on SOD in vivo and vitro, had proved that the irradiation can cause the SOD activity to decrease with the increase of irradiation dose, change some physicochemical properties and structure. This artical was to study the activity of SOD in Fish (Thearpon jorbua) and Toad(Bufo melanostictus) liver erythrocyte at sea area nearby Dayawan Nuclear Power Station (Nps). We found that the SOD activity in fish liver, after NPS revolved one year, was higher than that of before revoling (7.30 ± 1.35U/mg protein, 5.49 ±1.56 U/mg protein respectively). The SOD activity in the toad liver at NPS revolving one year after was decreased (4.54 ± 0.75 U/mg protein 5.68± 1.49U/mg protein P < 0.001) but in erythrocyte increased (2.32 ± 0.75 U/mg Hb, 0.70 ± 0.33 U/mg Hb P < 0.001). These results indicated that the SOD activity was changed in different with the animal variety. The effect of irradiation on fish at present was absent, on toad need to research in the future

  5. A stochastic movement simulator improves estimates of landscape connectivity.

    Coulon, A; Aben, J; Palmer, S C F; Stevens, V M; Callens, T; Strubbe, D; Lens, L; Matthysen, E; Baguette, M; Travis, J M J

    2015-08-01

    Conservation actions often focus on restoration or creation of natural areas designed to facilitate the movements of organisms among populations. To be efficient, these actions need to be based on reliable estimates or predictions of landscape connectivity. While circuit theory and least-cost paths (LCPs) are increasingly being used to estimate connectivity, these methods also have proven limitations. We compared their performance in predicting genetic connectivity with that of an alternative approach based on a simple, individual-based "stochastic movement simulator" (SMS). SMS predicts dispersal of organisms using the same landscape representation as LCPs and circuit theory-based estimates (i.e., a cost surface), while relaxing key LCP assumptions, namely individual omniscience of the landscape (by incorporating perceptual range) and the optimality of individual movements (by including stochasticity in simulated movements). The performance of the three estimators was assessed by the degree to which they correlated with genetic estimates of connectivity in two species with contrasting movement abilities (Cabanis's Greenbul, an Afrotropical forest bird species, and natterjack toad, an amphibian restricted to European sandy and heathland areas). For both species, the correlation between dispersal model and genetic data was substantially higher when SMS was used. Importantly, the results also demonstrate that the improvement gained by using SMS is robust both to variation in spatial resolution of the landscape and to uncertainty in the perceptual range model parameter. Integration of this individual-based approach with other developing methods in the field of connectivity research, such as graph theory, can yield rapid progress towards more robust connectivity indices and more effective recommendations for land management. PMID:26405745

  6. BZ UMa and Var Her 04: Orphan TOADS

    Price, A.; Howell, S.

    2005-05-01

    Both BZ UMa and Var Her 04 are cataclysmic variable stars without a home. Neither fit easily into current classification systems so may extend the population distribution of two unique CV types: UGWZ dwarf novae and intermediate polars. New outburst photometry and archival X-Ray data shed some new light on BZ UMa's high energy state and new spectral and IR observations from Spitzer of dust around the newly discovered cataclysmic variable Var Her 04 may help find it a home as well.

  7. Sex chromosome diversity in Armenian toad grasshoppers (Orthoptera, Acridoidea, Pamphagidae)

    Bugrov, Alexander G.; Jetybayev, Ilyas E.; Karagyan, Gayane H.; Rubtsov, Nicolay B.

    2016-01-01

    Abstract Although previous cytogenetic analysis of Pamphagidae grasshoppers pointed to considerable karyotype uniformity among most of the species in the family, our study of species from Armenia has discovered other, previously unknown karyotypes, differing from the standard for Pamphagidae mainly in having unusual sets of sex chromosomes. Asiotmethis turritus (Fischer von Waldheim, 1833), Paranocaracris rubripes (Fischer von Waldheim, 1846), and Nocaracris cyanipes (Fischer von Waldheim, 1846) were found to have the karyotype 2n♂=16+neo-XY and 2n♀=16+neo-XX, the neo-X chromosome being the result of centromeric fusion of an ancient acrocentric X chromosome and a large acrocentric autosome. The karyotype of Paranothrotes opacus (Brunner von Wattenwyl, 1882) was found to be 2n♂=14+X1X2Y and 2n♀=14+X1X1X2X2., the result of an additional chromosome rearrangement involving translocation of the neo-Y and another large autosome. Furthermore, evolution of the sex chromosomes in these species has involved different variants of heterochromatinization and miniaturization of the neo-Y. The karyotype of Eremopeza festiva (Saussure, 1884), in turn, appeared to have the standard sex determination system described earlier for Pamphagidae grasshoppers, 2n♂=18+X0 and 2n♀=18+XX, but all the chromosomes of this species were found to have small second C-positive arms. Using fluorescent in situ hybridization (FISH) with 18S rDNA and telomeric (TTAGG)n DNA repeats to yield new data on the structural organization of chromosomes in the species studied, we found that for most of them, clusters of repeats homologous to 18S rDNA localize on two, three or four pairs of autosomes and on the X. In Eremopeza festiva, however, FISH with labelled 18S rDNA painted C-positive regions of all autosomes and the X chromosome; clusters of telomeric repeats localized primarily on the ends of the chromosome arms. Overall, we conclude that the different stages of neo-Y degradation revealed in the Pamphagidae species studied make the family a very promising and useful model for studying sex chromosome evolution. PMID:27186337

  8. Middle Breton prezeffan 'vermin, toad, lizard'

    Jørgensen, Anders Richardt

    Middelbretonsk prezeffan, hidtil set som en uforklaret variant af preffan 'kryb' (diminutiv af preff 'orm'), tolkes nu i stedet som et selvstændigt leksem. Det afledes af et ældre *pezreffan, som svarer direkte til kornisk pedrevan 'firben'. En videre analyse identificerer første del af ordet som...

  9. Sex chromosome diversity in Armenian toad grasshoppers (Orthoptera, Acridoidea, Pamphagidae).

    Bugrov, Alexander G; Jetybayev, Ilyas E; Karagyan, Gayane H; Rubtsov, Nicolay B

    2016-01-01

    Although previous cytogenetic analysis of Pamphagidae grasshoppers pointed to considerable karyotype uniformity among most of the species in the family, our study of species from Armenia has discovered other, previously unknown karyotypes, differing from the standard for Pamphagidae mainly in having unusual sets of sex chromosomes. Asiotmethis turritus (Fischer von Waldheim, 1833), Paranocaracris rubripes (Fischer von Waldheim, 1846), and Nocaracris cyanipes (Fischer von Waldheim, 1846) were found to have the karyotype 2n♂=16+neo-XY and 2n♀=16+neo-XX, the neo-X chromosome being the result of centromeric fusion of an ancient acrocentric X chromosome and a large acrocentric autosome. The karyotype of Paranothrotes opacus (Brunner von Wattenwyl, 1882) was found to be 2n♂=14+X1X2Y and 2n♀=14+X1X1X2X2., the result of an additional chromosome rearrangement involving translocation of the neo-Y and another large autosome. Furthermore, evolution of the sex chromosomes in these species has involved different variants of heterochromatinization and miniaturization of the neo-Y. The karyotype of Eremopeza festiva (Saussure, 1884), in turn, appeared to have the standard sex determination system described earlier for Pamphagidae grasshoppers, 2n♂=18+X0 and 2n♀=18+XX, but all the chromosomes of this species were found to have small second C-positive arms. Using fluorescent in situ hybridization (FISH) with 18S rDNA and telomeric (TTAGG)n DNA repeats to yield new data on the structural organization of chromosomes in the species studied, we found that for most of them, clusters of repeats homologous to 18S rDNA localize on two, three or four pairs of autosomes and on the X. In Eremopeza festiva, however, FISH with labelled 18S rDNA painted C-positive regions of all autosomes and the X chromosome; clusters of telomeric repeats localized primarily on the ends of the chromosome arms. Overall, we conclude that the different stages of neo-Y degradation revealed in the Pamphagidae species studied make the family a very promising and useful model for studying sex chromosome evolution. PMID:27186337

  10. Teaduslikud töötoad osutusid magnetiks / Martin Pau

    Pau, Martin, 1975-

    2011-01-01

    Haridus- ja teadusministeeriumilt teaduse ja tehnoloogia populariseerimise eest preemia saanud maaülikooli doktorantide projekti «Elus teadus» õpitubades osales esimese kolme kuuga üle 800 koolilapse

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

    Larsen, Erik Hviid; Ussing, H H; Spring, K R

    1987-01-01

    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...... 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 uptake of Cl ions from the apical bath and K ions from the serosal bath. Bilateral...

  12. All-Optical Reversible Hybrid New Gate using TOAD

    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.

  13. Anticipatory motor patterns limit muscle stretch during landing in toads

    Azizi, Emanuel; Abbott, Emily M.

    2013-01-01

    To safely land after a jump or hop, muscles must be actively stretched to dissipate mechanical energy. Muscles that dissipate energy can be damaged if stretched to long lengths. The likelihood of damage may be mitigated by the nervous system, if anticipatory activation of muscles prior to impact alters the muscle's operating length. Anticipatory motor recruitment is well established in landing studies and motor patterns have been shown to be modulated based on the perceived magnitude of the i...

  14. 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....

  15. Effect of acrylamide toxicity on the ultrastructure of a single cell model Nyctotheroides puytoraci.

    Abdelmeguid, N

    1990-11-01

    Acrylamide (ACR), a widely used vinyl monomer, is well known as a neurotoxin to both laboratory animals and man. The experiment reported has demonstrated that ACR induces ultrastructural changes in the parasitic ciliate Nyctotheroides puytoraci, after injecting the host Bufo regularis with 1 mg ACR per toad (single dose). After 1 week of ACR injection, alterations in both nuclear and cytoplasmic organelles were observed. An increase in the number of cisternae of the Golgi complex was visualized which may be due to its division and hence activation. Acrylamide also appeared to cause fusion of mitochondria in the treated trophozoites. Thus trophozoites of these specimens showed a decreased number of irregularly shaped mitochondria with dense matrix and indistinct outer and inner membranes. Such changes may be attributed to a disturbance in mitochondrial protein synthesis. Also, rough endoplasmic reticulum and lysosomes increased in number. The basal cell bodies were degenerated at some sites. PMID:2125982

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

    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.

  17. Detection of poisoning by plant-origin cardiac glycoside with the Abbott TDx analyzer.

    Cheung, K; Hinds, J A; Duffy, P

    1989-02-01

    Cardiac glycoside poisoning caused by ingestion of plant material is common in tropical and sub-tropical areas. In evaluating the use of the Abbott TDx Digoxin II assay to detect such cases of poisoning, we found it a rapid and convenient method for confirming the ingestion of glycosides from the plants Nerium oleander, Thevetia peruviana, and Adonis microcarpa, and from the toad Bufo marinus. Here we report some clinical cases illustrating our experience with the use of this assay, and describe results of cross-reactivity studies with compounds structurally similar to digoxin. Because of the competitive nature of the immunoassay as well as the complexity of the mixture of cross-reacting cardiac glycosides present in the plant material, the measured apparent digoxin concentration is not linearly related to the cardiac glycoside concentration. PMID:2914377

  18. A bactericidal protein in Bombina variegata pachypus skin venom.

    Mastromei, G; Barberio, C; Pistolesi, S; Delfino, G

    1991-01-01

    The skin venom of the yellow bellied toad Bombina variegata pachypus has an antimicrobial activity which seems to be correlated to the presence of a 6700 mol. wt polypeptide. This polypeptide was purified by electroelution from SDS-urea-polyacrylamide gels and characterized for its antimicrobial activity. A bactericidal action was detected at concentrations with little or no cytolytic effect. The determination of the Minimal Inhibitory Concentration showed that there was activity against gram positive and gram negative bacteria and also against yeasts. The skin secretions of three other anuran species (Bufo viridis, Hyla arborea and Discoglossus pictus) were examined for the presence of antimicrobial activities. Only the Hyla arborea secretion exhibited antimicrobial properties. A small amount of a 6700 mol. wt polypeptide was detected among the Hyla secreted products. PMID:2048146

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

    Grant, Rachel A.; Halliday, Tim; Balderer, Werner P.; Leuenberger, Fanny; Newcomer, Michelle; Cyr, Gary; Freund, Friedemann T.

    2011-01-01

    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. PMID:21776211

  20. Bufo arenarum Hensel, 1867 (Amphibia: Anura: Bufonidae para el Noroeste del Uruguay

    Olmos, Alejandro

    1998-01-01

    Full Text Available Uruguay, Departamento de Paysandú. Paysandú. Puente Internacional, Comisión Administradora del Río Uruguay. 17 de mayo de 1995. Col: C. Ríos. Colección Zoología Vertebrados de la Facultad de Ciencias (Montevideo, Uruguay ZVCB 2758 (macho.Departamento de Salto. Salto. Club de Remeros. 27 de febrero de 1997. Col: A. Olmos ZVCB 3459 (hembra.

  1. Effect of cyclophosphamide on limb regeneration in stages of Bufo regularis reuss.

    Michael, M I; Aziz, F K; Fahmy, G H

    1993-01-01

    Pre-amputation treatment in both stages (53 and 56) caused a profound decline in limb regeneration abilities and gave heteromorphic regenerates with smaller number of toes in the early stage, while in the later one, it suppressed completely the regeneration of toes or toe protuberances; otherwise partial or complete restoration of the shank. CY treatment concomitant with amputation caused intensive enhancement of regeneration in the early stage, while in the later one it activated regeneration to a lesser degree. PMID:8302897

  2. Dipeptidyl peptidase-IV (DPP-IV inhibitory activity of parotid exudate of Bufo melanostictus

    Allenki Venkatesham

    2009-01-01

    Full Text Available Type 2 diabetes arises as a result of β-cell failure combined with concomitant insulin resistance. Glucagon-like peptide-1 is a gastrointestinal hormone that is released postprandially from the L cells of the gut and exerts a glucose- dependent and direct insulinotropic effect on the pancreatic β cell. Which activate adenylate cyclase and enhances insulin secretion. GLP-1 is rapidly degraded by DPP-IV to GLP-1(9-37 amide following release from gut L cells. GLP-1 directly enhances glucose-dependent insulin secretion via an increase in β-cell cAMP. Dipeptidyl peptidase IV (DPP-IV is a plasma membrane glycoprotein ectopeptidase. In mammals, DPP-IV was widely expressed on the surface of endothelial and epithelial cells and highest levels in humans have been reported to occur in the intestine, bone marrow and kidney. Inhibiting DPP-IV reduces its rapid degradation of GLP-1, increasing circulating levels of the active hormone in vivo and prolonging its beneficial effects. The IC 50 value of parotid exudate was found to be 9.4 μg/ml. The maximum % inhibition (61.8 was showed at a concentration of 12μg/ml. Parotid exudate through inhibition of DPP-IV, improves glucose tolerance and enhances insulin secretion. DPP-IV inhibitors are a novel class of oral hypoglycemic agents with a potential to improve pancreatic beta cell function and the clinical course of type 2 diabetes.

  3. Purification and Characterization of a New Antimicrobial Peptide from Skin Secretions of Bufo Kavirensis

    H Zare Zardini

    2014-04-01

    Results: A novel antimicrobial peptide was obtained from skin secretions. This peptide is composed of 20 amino acids. This peptide does not present any similarity with the other antimicrobial peptides from the amphibians. Thus, it was named Maximin Bk. The peptide was subjected to antimicrobial activity assays. The Buforin–Kpeptide showed considerable antimicrobial activity against Gram positive and Gram negative bacteria (minimum inhibitory concentrations (MIC, 8.1 to 20.78 µg/ml as well as fungi (MIC, 25.7 to 35.6 mg/ml. Moreover, this peptide showed higher antimicrobial activity against Gram-negative than against Gram-positive bacteria and fungi. Maximin Bk showed virtually low hemolytic activity, which, at a concentration of 100 μg/mL, induced 5% hemolysis. Thus, a very slight haemolytic activity was obtained against human erythrocytes. Conclusion: On the basis of the biological effects, Buforin–Kcan can be regarded as the potent agent for treatment of various microbial diseases.

  4. A preliminary report of amphibian mortality patterns on railways

    Karolina A. Budzik

    2014-06-01

    Full Text Available In contrast to road mortality, little is known about amphibian railroad mortality. The aim of this study was to quantify amphibian mortality along a railway line as well as to investigate the relationship between the availability of breeding sites in the surrounding habitats and the monthly variation of amphibian railway mortality. The study was conducted from April to July 2011 along 45 km of the railway line Kraków - Tarnów (Poland, Małopolska province. Three species were affected by railway mortality: Bufo bufo, Rana temporaria and Pelophylax kl. esculentus. Most dead individuals (77% were adult common toads. The largest number (14 of amphibian breeding sites was located in the most heterogeneous habitats (woodland and rural areas, which coincides with the sectors of highest amphibian mortality (42% of all accidents. As in the case of roads, spring migration is the period of highest amphibian mortality (87% of all accidents on railroads. Our findings suggest that railroad mortality depends on the agility of the species, associated primarily with the ability to overcome the rails.

  5. Body size affects the predatory interactions between introduced American Bullfrogs (Rana catesbeiana) and native anurans in China: An experimental study

    Wang, Y.; Guo, Z.; Pearl, C.A.; Li, Y.

    2007-01-01

    Introduced American Bullfrogs (Rana catesbeiana) have established breeding populations in several provinces in China since their introduction in 1959. Although Bullfrogs are viewed as a potentially important predator of Chinese native anurans, their impacts in the field are difficult to quantify. We used two experiments to examine factors likely to mediate Bullfrog predation on native anurans. First, we examined effects of Bullfrog size and sex on daily consumption of a common Chinese native (Rana limnocharis). Second, we examined whether Bullfrogs consumed similar proportions of four Chinese natives: Black-Spotted Pond Frog (Rana nigromaculata), Green Pond Frog (Rana plancyi plancyi), Rice Frog (R. limnocharis), and Zhoushan Toad (Bufo bufo gargarizans). We found that larger Rana catesbeiana consumed more R. limnocharis per day than did smaller R. catesbeiana, and that daily consumption of R. limnocharis was positively related to R. catesbeiana body size. When provided with adults of four anurans that differed significantly in body size, R. catesbeiana consumed more individuals of the smallest species (R. limnocharis). However, when provided with similarly sized juveniles of the same four species, R. catesbeiana did not consume any species more than expected by chance. Our results suggest that body size plays an important role in the predatory interactions between R. catesbeiana and Chinese native anurans and that, other things being equal, smaller species and individuals are at greater risk of predation by R. catesbeiana. Copyright 2007 Society for the Study of Amphibians and Reptiles.

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

    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.

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

    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

  8. Intramuscular Single-dose Toxicity Test of Bufonis venonum Pharmacopuncture in Sprague-Dawley Rats

    Lee, Kwang-Ho; Sun, Seung-Ho; Yu, Jun-Sang; Kwon, Ki-Rok

    2015-01-01

    Objectives: Bufonis venonum (BV) is the dried white secretions of the auricular and skin glands of the toads Bufo bufo gargarizans or Bufo melanosticus Schneider. This study was performed to evaluate the toxicity of intramuscularly- administered Bufonis venonum pharmacopuncture (BVP) and to calculate its approximate lethality through a single-dose test with Sprague-Dawley (SD) rats. Methods: Twenty male and 20 female 6-week-old SD rats were injected intramuscularly with BVP or normal saline. The animals were divided into four groups with five female and five male rats per group: the control group injected with normal saline at 0.5 mL/animal, the low-dosage group injected with 0.125 mL/animal of BVP, the medium-dosage group injected with 0.25 mL/animal of BVP and the high-dosage group injected with 0.5 mL/animal of BVP. All injections were in the left thighs of the rats. After administration, we conducted clinical observations everyday and body weight measurements on days 3, 7 and 14 after the injection. We also carried out hematology, serum biochemistry, and histological observations on day 15 after treatment. Results: No mortalities were observed in any experimental group. No significant changes in weight, hematology, serum biochemistry, and histological observations that could be attributed to the intramuscular injection of BVP were observed in any experimental group. Conclusion: Lethal dose of BVP administered via intramuscular injection in SD rats is over 0.5 mL/animal. PMID:26998390

  9. Tracking the spring migration of a bar-headed goose (Anser indicus) across the Himalaya with satellite telemetry

    Javed, S.; Takekawa, J.Y.; Douglas, D.C.; Rahmani, A.R.; Kanai, Y.; Nagendran, M.; Choudhury, B.C.; Sharma, S.

    2000-01-01

    Soil-food-chain-pesticide wildlife relationships were investigated to learn the concentration of pesticide residues present in soils, macro-invertebrates, vertebrates, and seeds as a result of annual applications of aldrin at recommended rates for pest control. Two central Missouri cornfields treated witb aldrin at 1 lb/acre, for 16 and 15 of the past 17 years, were selected for study during 1965-67. Primary samples collected for residue analyses included soils, earthworms (Lumbricidae), crickets (GryIlidae), and two kinds of ground beetles (Carabidae) obtained during early April, June, August, and October. Vertebrates and plant seeds collected during 1967 included white-footed mice (Peromyscus maniculatus), toads (Bufo americanus), snakes (Thamnophis sirtalis and Pituophis sayi), corn (Zea Mays), foxtail (Setaria Faberii), and annual sunflower (Helianthus annuus). Pesticide residues consisted primarily of dieldrin, the degradation product of aldrin. Combined aldrin and dieldrin residues, as two field all-season averages, wet weight basis, were: soils, 0.31 ppm; earthworms, 1.49 ppm; crickets, 0.23 ppm; Harpalus ground beetles, 1.10 ppm; Poecilus ground beetles, 9.67 ppm; white-footed mice, 0.98 ppm; toads, 3.53 ppm; garter snakes, 12.35 ppm; and corn, foxtail, and sunflower seeds less than 0.02 ppm each. Unusually high average residues (37.48 ppm) in Poecilus beetles during June, 1967, were attributed to abnormally high soil moisture and predacious feeding habits of these insects.

  10. Influenza em animais heterotérmicos Influenza in heterothermics

    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.

  11. TRATAMENTO DE CÃES ENVENENADOS EXPERIMENTALMENTE POR BUFADIENOLÍDEOS (SUBSTÂNCIAS ENCONTRADAS NA SECREÇÃO DAS GLÂNDULAS PARATÓIDES DOS SAPOS DO GÊNERO BUFO TREATMENT OF DOGS EXPERIMENTALLY POISONED BY BUFADIENOLIDES (SUBSTANCES FOUND IN THE SECRETION OF PARATOID GLANDS OF THE Bufo GENUS FROGS

    Paulo César Silva

    2007-09-01

    Full Text Available

    Os autores estudaram a administração de dois princípios medicamentosos no tratamento de dez cães envenenados experimentalmente por bufadienolídeos. A medicação utilizada atuou satisfatoriamente, ocorrendo a recuperação total em oito animais. Pelos resultados obtidos no presente experimento, podemos concluir: a A medicação utilizada atuou satisfatoriamente, e que nos animais envenenados em condições naturais, ela será tanto mais eficaz, quanto mais rapidamente for levada a efeito; b Com relação ao animal que morreu logo após ser medicado, a necrópsia e a histopatologia revelaram alterações orgânicas pré-existentes e que a nosso ver, foram agravadas através da ação do princípio tóxico utilizado.

    The authors studied the Atropin and Amplictil effects in the treatment of 10 dogs poisoned by bufadienolideos. Eight dogs clinically recovered.

  12. ROLE OF THE EGG JELLY COAT IN PROTECTING HYLA REGILLA AND BUFO CANORUS EMBRYOS FROM ULTRAVIOLET B RADIATION DURING DEVELOPMENT

    Previous studies have suggested that Ultraviolet B (UVB) radiation may play a role in amphibian population declines. Some of these studies also indicate that egg hatching success is unaltered in some species of anurans as a result of UVB exposure. It has been proposed that the eg...

  13. Ecology of anuran populations inhabiting thermally stressed aquatic ecosystems, with emphasis on larval Rana pipiens and Bufo terrestris

    Field and laboratory studies were conducted to determine the responses of anuran populations to thermally stressed aquatic ecosystems. Adult and larval amphibians were sampled in and around a cool arm of a 67 ha reservoir that receives high temperature effluent from a nuclear production reactor on the Savannah River Plant (SRP) in South Carolina. Patterns for some species were compared with data from nearby unheated areas and analyzed in terms of the thermal gradient (16-45 C) extending the length of the reservoir's cool arm. The adaptation to breeding during nocturnal rainfall fortuitously confers a double advantage especially to anurans breeding in thermally stressed waters. (U.S.)

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

    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.

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

    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.

  16. Invasive species as drivers of evolutionary change: cane toads in tropical Australia

    Shine, Richard

    2011-01-01

    The arrival of an invasive species can have wide-ranging ecological impacts on native taxa, inducing rapid evolutionary responses in ways that either reduce the invader's impact or exploit the novel opportunity that it provides. The invasion process itself can cause substantial evolutionary shifts in traits that influence the invader's dispersal rate (via both adaptive and non-adaptive mechanisms) and its ability to establish new populations. I briefly review the nature of evolutionary change...

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

    Majorová, H.; Roček, Zbyněk

    2004-01-01

    Roč. 260, č. 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

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

    Thomsen, Steffen Nyegaard; Wang, Tobias; Kristensen, Torsten

    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 cell...

  19. Why do green rods of frog and toad retinas look green?

    Govardovskii, Victor I; Reuter, Tom

    2014-09-01

    Amphibian “green” rods express a blue-sensitive cone visual pigment, and should look yellow. However,when observing them axially under microscope one sees them as green. We used single-cell microspectrophotometry (MSP) to reveal the basis of the perceived color of these photoreceptors. Conventional side-on MSP recording of the proximal cell segments reveals no selective longwave absorbing pigment explaining the green color. End-on MSP recording shows, in addition to the green rod visual pigment, an extra 2- to 4-fold attenuation being almost flat throughout the visible spectrum. This attenuation is absent in red (rhodopsin) rods, and vanishes in green rods when the retina is bathed in high-refractive media, and at wide illumination aperture. The same treatments change the color from green to yellow. It seems that the non-visual pigment attenuation is a result of slender green rod myoids operating as non-selective light guides. We hypothesize that narrow myoids, combined with photomechanical movements of melanin granules, allow a wide range of sensitivity regulation supporting the operation of green rods as blue receptors at mesopic-to low-photopic illumination levels.End-on transmittance spectrum of green rods looks similar to the reflectance spectrum of khaki military uniforms. So their greenness is the combined result of optics and human color vision. PMID:25015297

  20. REGIONAL DYNAMICS OF WETLAND-BREEDING FROGS AND TOADS: TURNOVER AND SYNCHRONY

    We used data from a statewide frog monitoring network to investigate population turnover and synchrony in eight wetland-breeding species. We found that subpopulations at many sites turn over frequently, with breeding choruses absent or undetectable in most years. Frequencies of d...

  1. Biochemical parameters during reproduction of the toad fish, Halobatrachus didactylus (Schneider, 1801)

    Rosety, Manuel; Blanco, Miguel; González de Canales, María Luisa; Grau, Amàlia; Sarasquete, Carmen

    1992-01-01

    [EN] Duringreproduction of Halobatrachus didactylus there are variations in thegonadosomatic and hepatosomatic indices. These variations are more marked infemales, with maximal values at the end of oogenesis and spermatogenesis. Serumcalcium concentration showed significant differences (P < 0.01), with highervalues in females and specially during the reproductive period (from January toApril). Hepatic and gonadal proteins also reach their maximum values in thisperiod. In gonads of both sexes ...

  2. The reaction of Xenopus laevis daudin (South African Toad) to linear accelerations

    Neubert, J.; Schatz, A.; Bromeis, B.; Briegleb, W.

    1994-08-01

    Preparing the German Spacelab Mission D-2 project ``Gravity Perception and Neuronal Plasticity'' - STATEX II - ground based experiments have been performed with larvae of the amphibian vertebrate Xenopus laevis Daud. to study the reactions to different levels of acceleration forces and profiles. The larvae have been exposed to accelerations of up to 5 g for different time periods using a modified laboratory centrifuge and the NIZEMI (Niedergeschwindigeits-Zentrifugen-Mikroskop) which allows direct observation and video documentation. The results will be discussed and compared with those of the D1-Mission, parabolic flights, and simulated weightlessness.

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

    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.

  4. Antimicrobial peptides from skin secretions of Chinese red belly toad Bombina maxima.

    Lai, Ren; Zheng, Yong Tang; Shen, Ji Hong; Liu, Guan Jie; Liu, Hen; Lee, Wen Hui; Tang, Shao Zhong; Zhang, Yun

    2002-03-01

    Two groups of antimicrobial peptides have been isolated from skin secretions of Bombina maxima. Peptides in the first group, named maximins 1, 2, 3, 4 and 5, are structurally related to bombinin-like peptides (BLPs). Unlike BLPs, sequence variations in maximins occurred all through the molecules. In addition to the potent antimicrobial activity, cytotoxicity against tumor cells and spermicidal action of maximins, maximin 3 possessed a significant anti-HIV activity. Maximins 1 and 3 were toxic to mice with LD(50) values of 8.2 and 4.3 mg/kg, respectively. Peptides in the second group, termed maximins H1, H2, H3 and H4, are homologous with bombinin H peptides. cDNA sequences revealed that one maximin peptide plus one maximin H peptide derived from a common larger protein. PMID:11835991

  5. There are abundant antimicrobial peptides in brains of two kinds of Bombina toads.

    Liu, Rui; Liu, Huan; Ma, Yufang; Wu, Jing; Yang, Hailong; Ye, Huahu; Lai, Ren

    2011-04-01

    It is well-known that there is a large amount of antimicrobial peptides in amphibian skins but few antimicrobial peptides are found in amphibian brains. Twenty-two and four antimicrobial peptides were purified and characterized from the brain homogenate of Bombina maxima and B. microdeladigitora, respectively. One hundred fifty-eight cDNA clones encoding 79 antimicrobial peptides were isolated from brain cDNA libraries of B. maxima and B. microdeladigitora. These antimicrobial peptides belong to two peptide groups (maximin and maximin-H). Twenty of them are identical to previously reported antimicrobial peptides (maximin 1-8, 10, 11, maximin H1, 3-5, 7, 9, 10, 12, 15, 16) from B. maxima skin secretions. Fifty-nine of them are novel antimicrobial peptides. Some of these antimicrobial peptides showed strong antimicrobial activities against tested microorganism strains including Gram-positive and -negative bacteria and fungi. The current diversity in peptide coding cDNA sequences is, to our knowledge, the most extreme yet described for any animal brains. The extreme diversity may give rise to interest to prospect the actual functions of antimicrobial peptides in amphibian brains. PMID:21338048

  6. Cane Toad or Computer Mouse? Real and Computer-Simulated Laboratory Exercises in Physiology Classes

    West, Jan; Veenstra, Anneke

    2012-01-01

    Traditional practical classes in many countries are being rationalised to reduce costs. The challenge for university educators is to provide students with the opportunity to reinforce theoretical concepts by running something other than a traditional practical program. One alternative is to replace wet labs with comparable computer simulations.…

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

    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 α subunits and the axonal projection into the brain in the olfactory system of the semiaquatic newt Cynops pyrrhogaster by immunostaining with antibodies against Gαolf and Gαo , by in situ hybridization using probes for Gαolf , Gαo , and Gαi2 , 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 Gαolf - and Gαo -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 Gαolf - and Gαo -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 Gαolf and extend their axons into the MOB. In the vomeronasal organ (VNO), the neurons mostly express Gαo . These neurons and quite a few Gαolf -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 Gαo , 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

  8. A new Cosmocercoides species (Nematoda: Cosmocercidae), C. tonkinensis n. sp., in the scale-bellied tree lizard (Acanthosaura lepidogaster) from Vietnam.

    Tran, Binh Thi; Sato, Hiroshi; Luc, Pham Van

    2015-09-01

    A new cosmocercid nematode species, Cosmocercoides tonkinensis n. sp., is described from the scale-bellied tree lizard (Acanthosaura lepidogaster) in the northern and central parts of Vietnam. The new species is characterized by medium-sized male worms (4.2-5.1 mm in length and 0.34-0.37 mm in width) relative to known members of the genus, with lateral alae, two sharply pointed spicules of equal length (0.22-0.26 mm in length), a gubernaculum (0.113-0.122 mm in length), 16 or 17 pairs of caudal rosettes, and the presence of somatic papillae. Female worms are slightly larger than male worms (5.3-5.5 mm in length and 0.32-0.42 mm in width), with the vulva situated at 3/5 from the anterior end, and elliptical embryonated eggs, 0.064- 0.084 mm long by 0.040-0.048 mm wide. From 19 recorded species of the genus, the morphology of C. tonkinensis n. sp. is closest to C. multipapillata, C. bufonis, and C. pulcher reported from toads and frogs in East Asia. The present new species is differentiated from them by the number of caudal rosettes, tail length relative to body length, presence of somatic papillae and lateral alae, and embryonated eggs. Furthermore, after C. variabilis in North America and C. sauria in Brazil, this new species is only the third species to be recorded from a reptilian host. The 18S ribosomal RNA gene (rDNA) of the new species is almost identical to that of C. dukae infecting land snails and slugs in North America. Between the present new species and C. pulcher from a toad (Bufo japonicus) in Japan, remarkably fewer nucleotide changes were noticed in the 18S to 28S rDNA including the internal transcribed spacer regions. The molecular phylogenetic position of the genus Cosmocercoides is briefly discussed. PMID:26204009

  9. Genotypic analysis of Mucor from the platypus in Australia.

    Connolly, J H; Stodart, B J; Ash, G J

    2010-01-01

    Mucor amphibiorum is the only pathogen known to cause significant morbidity and mortality in the free-living platypus (Ornithorhynchus anatinus) in Tasmania. Infection has also been reported in free-ranging cane toads (Bufo marinus) and green tree frogs (Litoria caerulea) from mainland Australia but has not been confirmed in platypuses from the mainland. To date, there has been little genotyping specifically conducted on M. amphibiorum. A collection of 21 Mucor isolates representing isolates from the platypus, frogs and toads, and environmental samples were obtained for genotypic analysis. Internal transcribed spacer (ITS) region sequencing and GenBank comparison confirmed the identity of most of the isolates. Representative isolates from infected platypuses formed a clade containing the reference isolates of M. amphibiorum from the Centraal Bureau voor Schimmelcultures repository. The M. amphibiorum isolates showed a close sequence identity with Mucor indicus and consisted of two haplotypes, differentiated by single nucleotide polymorphisms within the ITS1 and ITS2 regions. With the exception of isolate 96-4049, all isolates from platypuses were in one haplotype. Multilocus fingerprinting via the use of intersimple sequence repeats polymerase chain reaction identified 19 genotypes. Two major clusters were evident: 1) M. amphibiorum and Mucor racemosus; and 2) Mucor circinelloides, Mucor ramosissimus, and Mucor fragilis. Seven M. amphibiorum isolates from platypuses were present in two subclusters, with isolate 96-4053 appearing genetically distinct from all other isolates. Isolates classified as M. circinelloides by sequence analysis formed a separate subcluster, distinct from other Mucor spp. The combination of sequencing and multilocus fingerprinting has the potential to provide the tools for rapid identification of M. amphibiorum. Data presented on the diversity of the pathogen and further work in linking genetic diversity to functional diversity will provide critical information for its management in Tasmanian river systems. PMID:20090018

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

    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.

  11. A survey on the faunal diversity of Savar Upazila, Dhaka, Bangladesh.

    Hossain, Eftekhar; Chowdhury, Mohammad Mamun; Iqubal, Kazi Farhed

    2008-02-01

    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. PMID:18817158

  12. Acute toxicity of zinc to several aquatic species native to the Rocky Mountains.

    Brinkman, Stephen F; Johnston, Walter D

    2012-02-01

    National water-quality criteria for the protection of aquatic life are based on toxicity tests, often using organisms that are easy to culture in the laboratory. Species native to the Rocky Mountains are poorly represented in data sets used to derive national water-quality criteria. To provide additional data on the toxicity of zinc, several laboratory acute-toxicity tests were conducted with a diverse assortment of fish, benthic invertebrates, and an amphibian native to the Rocky Mountains. Tests with fish were conducted using three subspecies of cutthroat trout (Colorado River cutthroat trout Oncorhynchus clarkii pleuriticus, greenback cutthroat trout O. clarkii stomias, and Rio Grande cutthroat trout O. clarkii virginalis), mountain whitefish (Prosopium williamsoni), mottled sculpin (Cottus bairdi), longnose dace (Rhinichthys cataractae), and flathead chub (Platygobio gracilis). Aquatic invertebrate tests were conducted with mayflies (Baetis tricaudatus, Drunella doddsi, Cinygmula sp. and Ephemerella sp.), a stonefly (Chloroperlidae), and a caddis fly (Lepidostoma sp.). The amphibian test was conducted with tadpoles of the boreal toad (Bufo boreas). Median lethal concentrations (LC(50)s) ranged more than three orders of magnitude from 166 μg/L for Rio Grande cutthroat trout to >67,000 μg/L for several benthic invertebrates. Of the organisms tested, vertebrates were the most sensitive, and benthic invertebrates were the most tolerant. PMID:21811884

  13. Naturally occurring cardiac glycosides.

    Radford, D J; Gillies, A D; Hinds, J A; Duffy, P

    1986-05-12

    Cardiac glycoside poisoning from the ingestion of plants, particularly of oleanders, occurs with reasonable frequency in tropical and subtropical areas. We have assessed a variety of plant specimens for their cardiac glycoside content by means of radioimmunoassays with antibodies that differ in their specificity for cardiac glycosides. Significant amounts of immunoreactive cardiac glycoside were found to be present in the ornamental shrubs: yellow oleander (Thevetia peruviana); oleander (Nerium oleander); wintersweet (Carissa spectabilis); bushman's poison (Carissa acokanthera); sea-mango (Cerbera manghas); and frangipani (Plumeria rubra); and in the milkweeds: redheaded cotton-bush (Asclepias curassavica); balloon cotton (Asclepias fruiticosa); king's crown (Calotropis procera); and rubber vine (Cryptostegia grandifolia). The venom gland of the cane toad (Bufo marinus) also contained large quantities of cardiac glycosides. The competitive immunoassay method permits the rapid screening of specimens that are suspected to contain cardiac glycosides. Awareness of the existence of these plant and animal toxins and their dangers allows them to be avoided and poisoning prevented. The method is also useful for the confirmation of the presence of cardiac glycosides in serum in cases of poisoning. PMID:3086679

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

    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.

  15. Effects of oxamniquine on neuromuscular transmission.

    Adewunmi, C O; Ojewole, J A

    1985-06-01

    The effects of oxamniquine on neuromuscular transmission have been investigated in some experimental animals in an effort to unveil some of the unwanted effects of this commonly prescribed schistosomicide. Results obtained show that relatively low concentrations of the drug (oxamniquine, 10-100 micrograms/ml) potentiated acetylcholine-, carbachol- and nicotine-evoked contractions of the toad (Bufo regularis) isolated rectus abdominis muscle. Moderate to high concentrations of the compound (oxamniquine, 500 micrograms/ml and above) contracted rectus abdominis muscle preparations, and depressed indirect electrically-induced twitches of the rat isolated hemidiaphragm and chick isolated biventer muscle preparations. The depression of electrically-evoked twitches of the chick biventer and rat phrenic nerve-hemidiaphragm muscle preparations in vitro induced by moderate to high concentrations of oxamniquine (500 micrograms/ml and above) were resistant to bath-applied physostigmine (1-15 micrograms/ml), but deepened by d-tubocurarine (3-10 micrograms/ml). These findings suggest that the neuromuscular blocking action of oxamniquine is probably post-junctional in origin. PMID:2992404

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

    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.

  17. The straight and narrow path: the evolution of straight-line dispersal at a cane toad invasion front

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

    2014-01-01

    At the edge of a biological invasion, evolutionary processes (spatial sorting, natural selection) often drive increases in dispersal. Although numerous traits influence an individual's displacement (e.g. speed, stamina), one of the most important is path straightness. A straight (i.e. highly correlated) path strongly enhances overall dispersal rate relative to time and energetic cost. Thus, we predict that, if path straightness has a genetic basis, organisms in the invasion vanguard will exhi...

  18. A mathematical model of solute coupled water transport in toad intestine incorporating recirculation of the actively transported solute

    Larsen, E. H.; Sørensen, J. B.; Sørensen, Jens Nørkær

    2000-01-01

    A mathematical model of an absorbing leaky epithelium is developed for analysis of solute coupled water transport. The non-charged driving solute diffuses into cells and is pumped from cells into the lateral intercellular space (lis). All membranes contain water channels with the solute passing...... those of tight junction and interspace basement membrane by convection-diffusion. With solute permeability of paracellular pathway large relative to paracellular water flow, the paracellular flux ratio of the solute (influx/outflux) is small (2-4) in agreement with experiments. The virtual solute...... concentration of fluid emerging from lis is then significantly larger than the concentration in lis. Thus, in absence of external driving forces the model generates isotonic transport provided a component of the solute flux emerging downstream lis is taken up by cells through the serosal membrane and pumped...

  19. Turgid female toads give males the slip: a new mechanism of female mate choice in the Anura

    Bruning, Bas; Phillips, Benjamin L.; Shine, Richard

    2010-01-01

    In many anuran species, males vocalize to attract females but will grasp any female that comes within reach and retain their hold unless displaced by a rival male. Thus, female anurans may face strong selection to repel unwanted suitors, but no mechanism is known for doing so. We suggest that a defensive trait (the ability to inflate the body to ward off attack) has been co-opted for this role: by inflating their bodies, females are more difficult for males to grasp and hence, it is easier fo...

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

    Pedersen, Pil Birkefeldt Møller; Wang, Tobias; Brøndum, Emil Toft

    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...

  1. New species of Aplectana (Ascaridida: Cosmocercidae) in the toads, Rhinella granulosa and Rhinella schneideri (Anura: Bufonidae) from northern Argentina.

    Ramallo, Geraldine; Bursey, Charles R; Goldberg, Stephen R

    2008-12-01

    Aplectana adaechevarriae n. sp., from the large intestine of Rhinella granulosa and Rhinella schneideri, is described and illustrated. Of the 43 nominal species of Aplectana, A. adaechevarriae n. sp. represents the 23rd Neotropical species and the third species reported from Argentina. Of the Neotropical species, only 4, Aplectana elenae, Aplectana hylambatis, Aplectana raillieti, and A. adaechevarriae n. sp., have 8 pairs of preanal papillae. Aplectana adaechevarriae lacks a median preanal papilla; the other 3 species possess a median preanal papilla. PMID:18576778

  2. [Genetic variation in two forms of the common spadefoot toad Pelobates fuscus (Pelobatidae, Anura, Amphibia) distinguished by genome size].

    Khalturin, M D; Litvinchuk, S N; Borkin, L Ia; Rozanov, Iu M; Mil'to, K D

    2003-01-01

    Genetic differences (presumed 23 loci) between two cryptic forms of Pelobates fuscus, differing in genome size, were examined by means of polyacrylamide-gel electrophoresis. This method allowed to discriminate between these forms. Average genetic distance (DN) between both the forms was equal to 0.311, ranging from 0.055 to 0.563. As a rule, differences within these groups were smaller (0.021-0.388). The data show obvious genetic differentiation between these two cryptic forms of P. fuscus. Differences between these forms and P. syriacus were significantly higher (in average 0.943). Genetic distances in relation to speciation and species concepts are discussed. PMID:14520888

  3. A new genus and species of arboreal toad with phytotelmonous larvae, from the Andaman Islands, India (Lissamphibia, Anura, Bufonidae)

    Chandramouli, S. R.; Vasudevan, Karthikeyan; Harikrishnan, S.; Dutta, Sushil Kumar; Janani, S. Jegath; Sharma, Richa; Das, Indraneil; Aggarwal, Ramesh K.

    2016-01-01

    Abstract A new bufonid amphibian, belonging to a new monotypic genus, is described from the Andaman Islands, in the Bay of Bengal, Republic of India, based on unique external morphological and skeletal characters which are compared with those of known Oriental and other relevant bufonid genera. Blythophryne gen. n. is distinguished from other bufonid genera by its small adult size (mean SVL 24.02 mm), the presence of six presacral vertebrae, an absence of coccygeal expansions, presence of an elongated pair of parotoid glands, expanded discs at digit tips and phytotelmonous tadpoles that lack oral denticles. The taxonomic and phylogenetic position of the new taxon (that we named as Blythophryne beryet gen. et sp. n.) was ascertained by comparing its 12S and 16S partial genes with those of Oriental and other relevant bufonid lineages. Resulting molecular phylogeny supports the erection of a novel monotypic genus for this lineage from the Andaman Islands of India. PMID:26877687

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

    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...

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

    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...... 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...

  6. [Modeling a persistent infection by tick-borne encephalitis virus strains in a cell culture of the clawed toad].

    Izotov, V K; Chunikhin, S P

    1982-10-01

    Differences in the ability of 12 tick-borne encephalitis virus strains to induce persistent infection in the culture of clawed frog cells incubated at 26-32 degrees C were shown. In 8 strains the process of persistence was accompanied by the stable preservation of the infectious virus in the culture medium during 10 passages, while in 4 strains the virus disappeared already in passages 3-8. PMID:7180255

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

    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.

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

    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

    Roč. 20, č. 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

  9. Morphology, molecular genetics, and bioacoustics support two new sympatric Xenophrys toads (Amphibia: Anura: Megophryidae) in southeast China.

    Wang, Yingyong; Zhao, Jian; Yang, Jianhuan; Zhou, Zhixin; Chen, Guoling; Liu, Yang

    2014-01-01

    Given their recent worldwide declines and extinctions, characterization of species-level diversity is of critical importance for large-scale biodiversity assessments and conservation of amphibians. This task is made difficult by the existence of cryptic species complexes, species groups comprising closely related and morphologically analogous species. The combination of morphology, genetic, and bioacoustic analyses permits robust and accurate species identification. Using these methods, we discovered two undescribed Xenophrys species, namely Xenophrys lini sp. nov. and Xenophrys cheni sp. nov. from the middle range of Luoxiao Mountains, southeast China. These two new species can be reliably distinguished from other known congeners by morphological and morphometric differences, distinctness in male advertisement calls, and substantial genetic distances (>3.6%) based on the mitochondrial 16s and 12s rRNA genes. The two new species, together with X. jinggangensis, are sympatric in the middle range of Luoxiao Mountains but may be isolated altitudinally and ecologically. Our study provides a first step to help resolve previously unrecognized cryptic biodiversity and provides insights into the understanding of Xenophrys diversification in the mountain complexes of southeast China. PMID:24714161

  10. Erythrocyte Sizes of Some Anurans From Turkey

    ATATÜR, Mehmet K.; ARIKAN, Hüseyin; ÇEV?K, ?. Ethem

    1999-01-01

    The erythrocyte sizes of some anurans from Turkey (Rana ridibunda, Bufo bufo, Bufo viridis, Pelobates syriacus, Bombina bombina, Hyla arborea) were established utilizing blood smears stained with Wright's stain. The largest erythrocytes were found in R. ridibunda, the widest in B. bombina and the smallest in P. syriacus.

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

    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)

  12. Estudios exprimentales en larvas de Bufo fernandezae Gallardo. Crecimiento longitudinal y su relación con el alimento, concentración de oxígeno y densidad (Amphibia: Anura

    Kehr, Arturo Ignacio

    1985-01-01

    Full Text Available The objective of this work is to analyze individual and combined effects of biotic and abiotic factors of the length growth of inmature stages of B. fernandezae Gallardo. The research was carried on under specified and constant laboratory conditions. The obtained results showed that the density was the main controlling factor upon the individual growth, being less important, in this sense, the alimentary offer arranged during the temporal extension of the experiments. Besides, no differences were detected between the reared spawns, under different disolved oxygen registered values. Furthermore, it is remarkable food abundance and accesibility influence on the successful development of the studied individuals.

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

    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.

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

    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 μGy · h-1 and 6.96 E-03 μGy · h-1 respectively, the total dose rate is 8.65 E-03 μGy · h-1. The dose rates of 90Sr and 137Cs for teal are 1.56 E-04 μGy · h-1 and 2.68 E-04EμGy · h-1, the total dose rate is 4.24E-04 μGy · h-1. The dose rates of 90Sr and 137Cs for dry duck are 2.04E-04 μGy · h-1 and 2.29 E-04EμGy · h-1, the total dose rate is 4.33E-04 μGy · h-1. The total dose rates of the reference animals are well below the IAEA recommended dose limit for terrestrial animals (40 μGy · 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 μGy · h-1, which is well below the IAEA recommended dose limit for terrestrial plants (400 μGy · h-1). (authors)

  15. Pseudacris triseriata (western chorus frog) and Rana sylvatica (wood frog) chytridiomycosis

    Rittman, S.E.; Muths, E.; Green, D.E.

    2003-01-01

    The chytrid fungus Batrachochytrium dendrobatidis is a known pathogen of anuran amphibians, and has been correlated with amphibian die-offs worldwide (Daszak et. al. 1999. Emerging Infectious Diseases 5:735-748). In Colorado, B. dendrobatidis has infected Boreal toads (Bufo boreas) (Muths et. al., in review) and has been identified on museum specimens of northern leopard frogs (Rana pipiens) (Carey et. al. 1999. Develop. Comp. Immunol. 23:459-472). We report the first verified case of chytrid fungus in chorus frogs (Pseudacris triseriata) and wood frogs (Rana sylvatica) in the United States. We collected seven P. triseriata, and two adult and two juvenile R. sylvatica in the Kawuneeche Valley in Rocky Mountain National Park (RMNP) during June 2001. These animals were submitted to the National Wildlife Health Center (NWHC) as part of an amphibian health evaluation in RMNP. Chorus frogs were shipped in one container. Wood frog adults and juveniles were shipped in two separate containers. Histological examinations of all chorus frogs and 3 of 4 wood frogs were positive for chytrid fungus infection. The fourth (adult) wood frog was too decomposed for meaningful histology. Histological findings consisted of multifocally mild to diffusely severe infections of the epidermis of the ventrum and hindlimb digital skin. Chytrid thalli were confined to the thickened epidermis (hyperkeratosis), were spherical to oval, and occasional thalli contained characteristic discharge pores or zoospores (Green and Kagarise Sherman 1999. J. Herpetol 35:92-103; Fellers et al. 2001. Copeia 2001:945-953). We cannot confirm that all specimens carried the fungus at collection, because infection may have spread from one individual to all other individuals in each container during transport. Further sampling of amphibians in Kawuneeche Valley is warranted to determine the rate of infection and mortality in these populations.

  16. Chytridiomycosis widespread in Anurans of Northeastern United States

    Longcore, J.R.; Longcore, J.E.; Pessier, Allan P.; Halteman, W.A.

    2007-01-01

    An emerging disease of amphibians caused by the chytrid fungus Batrachochytrium dendrobatidis has been associated with morbidity, mortality, and extinction of species. Typically, researchers have detected B. dendrobatidis only when examining amphibians for causes of mortalities; few data exist on infection rates where mortalities are lacking. During May?September 2000?2002 we obtained amphibian specimens killed by vehicles and others collected at remote off-road sites throughout Maine, USA, and from federal lands in 5 states in the Northeast. We detected infected specimens, mostly green frogs (Rana clamitans), at 5 of 7 national wildlife refuges, a federal waterfowl production area, and Acadia National Park. Seven of 9 species, including all Ranidae species, were infected throughout Maine; rates ranged from 14.6% in American toads (Bufo americanus) to 25.7% in northern leopard frogs (Rana pipiens). We did not detect any infections in 50 eastern gray tree frogs (Hyla versicolor) or 21 spring peepers (Pseudacris crucifer). Species that hibernate in terrestrial habitats seem to have lower rates of infection than species that hibernate in aquatic habitats. Infections peaked in spring and autumn and were associated with air temperatures optimal for B. dendrobatidis growth. The relatively high infection rates among species without documented die-offs suggest that either losses have occurred undetected, that the fungus is endemic and species have attained a level of resistance to infections becoming lethal, or that climatic conditions of the Northeast have a role in preventing infections from being lethal. Data on prevalence and distribution of this chytrid fungus in the Northeast may be useful in modeling its origins and predicting long-term ecosystem effects involving anurans.

  17. Terrestrial exposure and effects of Headline AMP(®) Fungicide on amphibians.

    Cusaac, J Patrick W; Mimbs, William H; Belden, Jason B; Smith, Loren M; McMurry, Scott T

    2015-08-01

    Recent studies have demonstrated that a pyraclostrobin-containing fungicide (Headline(®) Fungicide--Headline(®) Fungicide and Headline AMP(®) Fungicide are registered trademarks of BASF) is toxic to amphibians at environmentally relevant concentrations. However, these studies were performed in a laboratory setting of a worst-case direct exposure in clean media. Interception of spray by the crop canopy and ground cover used by animals for security cover will influence exposure. Thus, risk to amphibians is unclear in an environmentally realistic field environment. We tested exposure and toxicity of Headline AMP(®) Fungicide to amphibians in multiple agricultural habitat scenarios (e.g., within treated crop vs. grassy areas adjacent to crop) and at two rates during routine aerial application. Specifically, we placed Woodhouse's toads (Bufo woodhousii) and Blanchard's cricket frogs (Acris blanchardi) in enclosures located within treated and untreated corn (VT stage, approximate height = 3 m), and in the potential drift area (adjacent to treated corn) during aerial application of Headline AMP Fungicide at either 731 or 1052 ml/ha (70 and 100 % the maximum application rate in corn, respectively). Mean concentrations of pyraclostrobin measured at ground level were ?19 % of nominal application rate in all areas. Overall, mean mortality of recovered individuals of both species was ?15 %, and mortality within Headline AMP Fungicide-treated corn (where risk was anticipated to be highest) was <10 %. It is important to understand that application timing, interception by the crop canopy (which varies both within and between crop systems), and timing of amphibian presence in the crop field influences risk of exposure and effects; however, our results demonstrate that amphibians inhabiting VT stage corn during routine aerial application of Headline AMP Fungicide are at low risk for acute mortality, matching existing laboratory results from acute toxicity studies of Headline Fungicide. PMID:26088505

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

    Corn, Paul Stephen

    1994-01-01

    The problem of declining amphibian species is thought to be particularly acute in western North America, but there are many gaps in our knowledge. Although several declines have been well-documented, other declines are anecdotal or hypothesized. Most documented declines are of ranid frogs or toads (Bufo). Species from montane habitats and those occurring in California have been best studied. Status of many desert species is unknown. Habitat destruction and introduced predators are the most common threats to amphibian populations. Some declines may represent natural variation in population size. Causes have not been determined for several cases where common species have declined over large areas. There are important considerations for ecosystem management, whether changes in amphibian populations are natural or caused by human activities. Causes for declines must be known so that management can be prescribed (or proscribed) to eliminate or minimize these causes. The natural variability of amphibian population numbers and the complexity of metapopulation structure emphasize the necessity of considering multiple temporal and spatial scales in ecosystem management. The decline of amphibian species throughout the world has received considerable recent attention (e.g., Blaustein and Wake 1990, Griffiths and Beebee 1992, Yoffe 1992). Much of this attention derives from a workshop held in February, 1990 on declining amphibians sponsored by the National Research Council Board (NRC) on Biology in Irvine, California (Barinaga 1990, Borchelt 1990). Because of media attention in the aftermath of this conference, it is a popular perception that amphibian declines are a new phenomenon that herpetologists have been slow to recognize (Griffiths and Beebee 1992, Quammen 1993). However, concern about amphibian populations in the United States dates back over 20 years. Beginning in the 1960s, a large, well-documented decline of northern leopard frogs (Rana pipiens) occurred in the upper Midwest (Gibbs et al. 1971, Hine, 1981, Rittshof 1975).

  19. Responses of pond-breeding amphibians to wildfire: short-term patterns in occupancy and colonization.

    Hossack, Blake R; Corn, Paul Stephen

    2007-07-01

    Wildland fires are expected to become more frequent and severe in many ecosystems, potentially posing a threat to many sensitive species. We evaluated the effects of a large, stand-replacement wildfire on three species of pond-breeding amphibians by estimating changes in occupancy of breeding sites during the three years before and after the fire burned 42 of 83 previously surveyed wetlands. Annual occupancy and colonization for each species was estimated using recently developed models that incorporate detection probabilities to provide unbiased parameter estimates. We did not find negative effects of the fire on the occupancy or colonization rates of the long-toed salamander (Ambystoma macrodactylum). Instead, its occupancy was higher across the study area after the fire, possibly in response to a large snowpack that may have facilitated colonization of unoccupied wetlands. Naive data (uncorrected for detection probability) for the Columbia spotted frog (Rana luteiventris) initially led to the conclusion of increased occupancy and colonization in wetlands that burned. After accounting for temporal and spatial variation in detection probabilities, however, it was evident that these parameters were relatively stable in both areas before and after the fire. We found a similar discrepancy between naive and estimated occupancy of A. macrodactylum that resulted from different detection probabilities in burned and control wetlands. The boreal toad (Bufo boreas) was not found breeding in the area prior to the fire but colonized several wetlands the year after they burned. Occupancy by B. boreas then declined during years 2 and 3 following the fire. Our study suggests that the amphibian populations we studied are resistant to wildfire and that B. boreas may experience short-term benefits from wildfire. Our data also illustrate how naive presence-non-detection data can provide misleading results. PMID:17708217

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

    Brome McCreary

    2009-12-01

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

  1. The influence of climate on the distribution of monogeneans of anurans in Nigeria.

    Aisien, S O; Salami, L A; Obaro, F E; Erakpoweri, S O

    2004-06-01

    Investigations undertaken on the monogeneans of amphibians in Nigeria have shown that host ecology has an influence on the distribution of these monogeneans. Amphibians from humid environments of the rainforest, a freshwater swamp and mangrove harboured no monogeneans, whereas those occurring in drier conditions in the savannah-mosaic and guinea savannah yielded five species of polystomatid parasites: Polystoma prudhoei from Bufo regularis, Polystoma galamensis from Rana galamensis, Eupolystoma alluaudi from Bufo regularis and Bufo maculatus, and two unidentified Polystoma species from Bufo regularis and Ptychadena oxyrynchus, respectively. Some of these monogeneans appear to have reproduction cycles which are synchronized with those of the hosts. The prevalence of E. alluaudi in Bufo spp. caught in New Bussa (68.4% in B. regularis and 82.3% in B. maculatus) were higher than those reported for this parasite in other locations in West Africa and for Eupolystoma anterorchis in Bufo pardalis from the Cape Flats of South Africa. PMID:15153280

  2. Integrating transportation and resource conservation planning

    Eastwood, Stephen; Winter, Kirsten Winter

    2005-01-01

    Forest in southern California has been evaluating and mitigating the effects of roads and road crossings on this species. To date, we have closed five miles of roads within toad habitat and have constructed seven crossings to reduce or eliminate the effect of the crossings on toads. Prior to this effort, most of the stream crossings in toad habitat were unimproved and vehicles drove directly through the stream. This caused several problems for toads: 1. While crossing the stream, vehicles wou...

  3. Drug: D06750 [KEGG MEDICUS

    Full Text Available D06750 Crude, Drug Toad venom ... (JP16) Hellebrin [CPD:C08868], Resibufogenin [CPD:C17058], Cinobuf ... or external use Drugs for external use D06750 Toad venom ... Crude drugs [BR:br08305] Animals Amphibians D06750 ... Toad venom ... PubChem: 47208401 ...

  4. Geology and petrography of the basaltic rocks (Arapey formation) cropping out in toad 4 between Arapey river (92 km) and Artigas (200 Km)

    This contribution presents a geological map of the basaltic flows of Arapey formation (Mezosoic) cropping out in Road 4 between the Arapey river (92 Km) and Artigas city (200 Km) together with the description of the petrographic features of the different portions of the 13 recognized flow units. (author)

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

    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.): α- and β-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 μg a.i./L) over a period of 28 days. Tadpoles showed reduced survival at the highest endosulfan concentrations (100 μg/L). Survival of tadpoles undergoing metamorphosis was not influenced by Tihan®. Endosulfan in concentrations of 10 and 100 μg/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 μg a.i./L (25 and 26 μg/kg wet weight (w/w) for the sum of α-endosulfan, β-endosulfan and endosulfan sulphate and below the detection limits for flubendiamide and spirotetramat). For the 100 μg a.i./L treatments, 1,600 μg/kg w/w was found of α-endosulfan, β-endosulfan and endosulfan sulphate together in the survived tadpoles and 21 μg/kg w/w of flubendiamide. PMID:25192667

  6. Altered gravitational experience during early periods of life affects the static vestibulo-ocular reflex of tadpoles of the southern clawed toad, Xenopus laevis Daudin.

    Sebastian, C; Esseling, K; Horn, E

    1996-11-01

    The effects of altered gravitational forces (AGF) on the development of the static vestibulo-ocular reflex (VOR) were investigated in Xenopus laevis tadpoles exposed to hypergravity (1.4g; 3g) or microgravity conditions (German spacelab mission D-2) for 9-10 days. The effects of light conditions during development were also tested by exposing tadpoles to either complete darkness (DD) or 12:12 h light-dark conditions (LD). The static VOR was induced by lateral roll. The efficacy of the VOR circuit after termination of AGF conditions was described by the peak-to-peak amplitude of the sinusoidal VOR characteristics (i.e. amplitude). The static VOR was first observed at stage 41 for both LD and DD tadpoles. Its further development was retarded in the DD tadpoles compared with the LD tadpoles up to stage 48. Microgravity as well as hypergravity exposure caused a significant (P 4g group and 24.9-42.9% in the 3g group compared with the 1g ground-reared siblings at the same developmental stages. The response deficits usually disappeared but persisted for at least 2 weeks in animals whose development was retarded by hypergravity exposure. It is postulated (i) that gravity exerts an important influence on the normal development of the roll-induced static VOR; (ii) that hypergravity exposure decreases the sensitivity of the gravity-sensitive system so that recordings under 1g conditions cause a weaker static VOR; and (iii) that the vestibulo-spinal pathway possesses a higher degree of plasticity than the vestibulo-ocular pathway. PMID:8951390

  7. A new species of Andean toad (Bufonidae, Osornophryne discovered using molecular and morphological data, with a taxonomic key for the genus

    Diego Paez

    2011-06-01

    Full Text Available Combining a molecular phylogeny and morphological data, we discovered a new species of Osornophryne from the Amazonian slope of the Ecuadorian Andes. Morphologically, the new taxon is distinguished from all others species in Osornophryne bythe Toes IV and V longer than Toes I–III, a short and rounded snout with a small rostral papilla, and conical pustules on flanks. The new species previously was confused with O. guacamayo. A taxonomic key is provided for all known species of Osornophryne.

  8. Ecological immunization: in situ training of free-ranging predatory lizards reduces their vulnerability to invasive toxic prey.

    Ward-Fear, G; Pearson, D J; Brown, G P; Rangers, Balanggarra; Shine, R

    2016-01-01

    In Australia, large native predators are fatally poisoned when they ingest invasive cane toads (Rhinella marina). As a result, the spread of cane toads has caused catastrophic population declines in these predators. Immediately prior to the arrival of toads at a floodplain in the Kimberley region, we induced conditioned taste aversion in free-ranging varanid lizards (Varanus panoptes), by offering them small cane toads. By the end of the 18-month study, only one of 31 untrained lizards had survived longer than 110 days, compared to more than half (nine of 16) of trained lizards; the maximum known survival of a trained lizard in the presence of toads was 482 days. In situ aversion training (releasing small toads in advance of the main invasion front) offers a logistically simple and feasible way to buffer the impact of invasive toads on apex predators. PMID:26740565

  9. Fab antibody fragments: some applications in clinical toxicology.

    Flanagan, Robert J; Jones, Alison L

    2004-01-01

    This review provides current information on the use of antigen-binding fragments (Fab) from cleaved antibodies to treat poisoning with digoxin and other potent, low formula mass poisons, such as colchicine and tricyclic antidepressants. Anti-digoxin Fab fragments have been used successfully for many years in the management of severe poisoning with digoxin, digitoxin, and a range of other structurally related compounds, including cardiotoxins from Nerium and Thevetia sp. (oleander) and Bufo sp. (toads). However, their main use remains treating digoxin poisoning. Equimolar doses of anti-digoxin Fab fragments completely bind digoxin in vivo. The approximate dose of Fab fragments (mg) is 80 times the digoxin body burden (mg). If neither the dose ingested nor the plasma digoxin/digitoxin concentration is known, in an adult 380 mg of anti-digoxin Fab fragments should be given. The dose for elderly patients or those with renal impairment should be similar to that for those with normal renal function. Fab fragments have a plasma half-life of 12-20 hours, but this can be prolonged in patients with renal impairment. Analysis of serum ultrafiltrate using an immunoassay shown not to have matrix bias remains the most accurate approach to measuring free digoxin in the presence of anti-digoxin Fab fragments. The antibody fragments are given intravenously over 15-30 minutes after dilution to at least 250 mL with plasma protein solution, 0.9% (w/v) sodium chloride, or deionised water, except in infants where the volume infused can be reduced. Factors limiting the efficacy of Fab fragments are the dose, the duration of the infusion and any delay in administration. Guidelines for Fab fragment administration in children include (i) dilution to a final Fab concentration of 10 g/L in either 5% (w/v) dextrose or 0.9% (w/v) sodium chloride; (ii) infusion through a 0.22 microm filter; (iii) administration of the total dose over a minimum of 30 minutes; and (iv) avoiding coadministration of other drugs and/or electrolyte solutions. Fab fragments are generally well tolerated. Adverse effects attributable to Fab treatment include hypokalaemia and exacerbation of congestive cardiac failure; renal function could be impaired in some patients. Fab fragment preparations for treating acute colchicine and tricyclic antidepressant poisoning have been developed, but are not available commercially. Colchicine poisoning is rare in Western countries, and pharmacological management together with supportive care is usually effective even in severe tricyclic antidepressant overdosage. Attempts have been made to produce anti-paraquat antibodies capable of enhancing paraquat elimination from the lung, but thus far all such attempts have proved unsuccessful. PMID:15554746

  10. Annual Proxy Records from Tropical Cloud Forest Trees in the Monteverde Cloud Forest, Costa Rica

    Anchukaitis, K. J.; Evans, M. N.; Wheelwright, N. T.; Schrag, D. P.

    2005-12-01

    The extinction of the Golden Toad (Bufo periglenes) from Costa Rica's Monteverde Cloud Forest prompted research into the causes of ecological change in the montane forests of Costa Rica. Subsequent analysis of meteorological data has suggested that warmer global surface and tropical Pacific sea surface temperatures contribute to an observed decrease in cloud cover at Monteverde. However, while recent studies may have concluded that climate change is already having an effect on cloud forest environments in Costa Rica, without the context provided by long-term climate records, it is difficult to confidently conclude that the observed ecological changes are the result of anthropogenic climate forcing, land clearance in the lowland rainforest, or natural variability in tropical climate. To address this, we develop high-resolution proxy paleoclimate records from trees without annual rings in the Monteverde Cloud Forest in Costa Rica. Calibration of an age model in these trees is a fundamental prerequisite for proxy paleoclimate reconstructions. Our approach exploits the isotopic seasonality in the δ18O of water sources (fog versus rainfall) used by trees over the course of a single year. Ocotea tenera individuals of known age and measured annual growth increments were sampled in long-term monitored plantation sites in order to test this proposed age model. High-resolution (200μm increments) stable isotope measurements on cellulose reveal distinct, coherent δ18O cycles of 6 to 10‰. The calculated growth rates derived from the isotope timeseries match those observed from basal growth increment measurements. Spatial fidelity in the age model and climate signal is examined by using multiple cores from multiple trees and multiple sites. These data support our hypothesis that annual isotope cycles in these trees can be used to provide chronological control in the absence of rings. The ability of trees to record interannual climate variability in local hydrometeorology and remote climate forcing is evaluated using the isotope signal from multiple trees, local meteorological observations, and climate field data for the well-observed 1997-1998 warm El Niño-Southern Oscillation (ENSO) event. The successful calibration of our age model is a necessary step toward the development of long, annually-resolved paleoclimate reconstructions from old trees, even without rings, which will be used to evaluate the cause of recent observed climate change at Monteverde and as proxies for tropical climate field reconstructions.

  11. Valge fungi uus tulemine / Kersti Pikk

    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

  12. Resumen de las excursiones realizadas a la laguna de La Nava (Fuentes de Nava, Palencia) entre 1950 y 1953, y listado de las especies observadas

    Valverde Gómez, José Antonio, 1926-2003

    2008-01-01

    Resumen de las excursiones realizadas a la laguna de La Nava (Fuentes de Nava, Palencia) entre 1950 y 1953, y listado de las especies observadas, entre las que se encuentran los siguientes peces: Barbus sp. (Barbo), Carassius auratus (Pez rojo) y Tinca tinca (Tenca),los siguientes anfibios: Bufo bufo (Sapo común, llamado B.vulgaris por el autor), Epidalea calamita (Sapo corredor, llamado Bufo calamita por el autor), Molge sp. (que seguramente equivale a "Tritón" ,probablemente, Lissotriton sp...

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

    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.

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

    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.

  15. Optical Time Division Multiplexing Using Terahertz Optical Asymmetric Demultiplexer

    Kaur, Kamaldeep; Bhatia, K. S.

    2015-12-01

    In this paper, optical time division multiplexing is demonstrated using TOAD (terahertz optical asymmetric demultiplexer), which employs semiconductor optical amplifier (SOA) as nonlinear switching element. The TOAD device in its original configuration is based on Sagnac interferometer (also referred to as nonlinear optical loop mirror - NOLM).

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

    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.

  17. Nomenclatural notes on living and fossil amphibians

    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 y actuales en estado fósil (Allocaudata, Anura y Caudata ha permitido detectar diversos casos que precisan cambios nomenclaturales a fin de estabilizar la taxonomía del grupo. Los cambios nomenclaturales incluyen homonimias, correcciones de variantes gramaticales y autorías, disponibilidad de nombres, y en especial la propuesta de nuevas combinaciones, necesarias para ajustar algunos taxones paleontológicos a los modelos de relaciones evolutivas entre formas vivientes, fundamentados en filogenias moleculares. Las nuevas combinaciones que se proponen son: Anaxyrus defensor para Bufo defensor Meylan, 2005; Anaxyrus hibbardi para Bufo hibbardi Taylor, 1937; Anaxyrus pliocompactilis para Bufo pliocompactilis Wilson, 1968; Anaxyrus repentinus para Bufo repentinus Tihen, 1962; Anaxyrus rexroadensis para Bufo rexroadensis Tihen, 1962; Anaxyrus spongifrons para Bufo spongifrons Tihen, 1962; Anaxyrus suspectus para Bufo suspectus Tihen, 1962; Anaxyrus tiheni para Bufo tiheni Auffenberg, 1957; Anaxyrus valentinensis para Bufo valentinensis Estes et Tihen, 1964; Ichthyosaura wintershofi para Triturus wintershofi Lunau, 1950; Incilius praevius para Bufo praevius Tihen, 1951; Lithobates bucella para Rana bucella Holman, 1965; Lithobates dubitus para Anchylorana dubita Taylor, 1942; Lithobates fayeae para Rana fayeae Taylor, 1942; Lithobates miocenicus para Rana miocenica Holman, 1965; Lithobates moorei para Anchylorana moorei Taylor, 1942; Lithobates parvissimus para Rana parvissima Taylor, 1942; Lithobates rexroadensis para Rana rexroadensis Taylor, 1942; Lithobates robustocondylus para Anchylorana robustocondyla Taylor, 1942; Ommatotriton roehrsi para Triturus roehrsi Herre, 1955; Pelophylax barani para Rana barani Rückert-Ülkumen, 1980; Pelophylax meriani para Rana meriani Meyer, 1853; Pelophylax pueyoi para Rana pueyoi Navás, 1922a; Pelophylax quellenbergi para Rana quellenbergi Navás, 1922; Philoria borealis para Kyarranus borealis Tyler, 1991; Pseudepidalea belogorica para Bufo belogoricus Ratnikov, 1993; Pseudepidalea plana para Bufo planus Ratnikov, 1993; Pseudepidalea prisca para Bufo priscus Spinar, Klembara et Meszáros, 1993, y Pseudepidalea stranensis para Bufo stranensis Nemec, 1972. Los nombres Geyeriellinae Brame, 1958, Palaeurodelidae Brame, 1958, Prosalamandridae Stefano, 1903, Lipelucidae Huene, 1956, Rana temporaria fossilis Stefanov, 1951, Salteniidae Kuhn, 1962, Vieraellidae Reig, 1961, y Voigtiellinae Brame, 1958 se consideran nomenclaturalmente no disponibles. El nombre de familia basado en Scapherpeton Cope, 1876 es Scapherpetidae y no Scapherpetonidae ni Scapherpetontidae.

  18. Ontogenetic shifts in a prey's chemical defences influence feeding responses of a snake predator.

    Llewelyn, John; Bell, Kris; Schwarzkopf, Lin; Alford, Ross A; Shine, Richard

    2012-08-01

    Foraging theory suggests that predator responses to potential prey should be influenced by prey chemical defences, but the effects of ontogenetic variation in such defences on prey vulnerability to predators remain unclear. Cane toads (Rhinella marina) are toxic to anurophagous snakes, including the keelback (Tropidonophis mairii, a natricine colubrid that occurs within the toads' invasive range in Australia). Toxin levels and diversity change through toad ontogeny, decreasing from the egg stage to metamorphosis, then increasing in postmetamorphic toads. If the toxin content of a prey item influences predator responses, we predict that keelbacks should exhibit selective predation on toads close to metamorphosis. The results of our laboratory trials on adult (field-collected, and thus toad-experienced) and hatchling (laboratory-incubated, and thus toad-naive) keelbacks supported this prediction. The snakes selectively consumed later-stage rather than earlier-stage tadpoles, and earlier-stage rather than later-stage metamorphs. Our data are thus consistent with the hypothesis that ontogenetic changes in toxin content can affect individuals' vulnerability to predation. PMID:22302513

  19. SURROGATE SPECIES IN ASSESSING CONTAMINANT RISK FOR ENDANGERED FISHES

    Rainbow trout, fathead minnows, and sheepshead minnows were tested as surrogate species to assess contaminant risk for 17 endangered fishes and one toad species. Acute toxicity tests were conducted with carbaryl, copper, 4-nonylphenol, pentachlorophenol, and permethrin in accord...

  20. SURROGATE SPECIES IN ASSESSING CONTAMINANT RISK FOR ENDANGERED FISHES, INCLUDING INTERSPECIES TOXICITY CORRELATIONS

    Rainbow trout, fathead minnows, and sheepshead minnows were tested as surrogate species to assess contaminant risk for 17 endangered fishes and one toad species. Acute toxicity tests were conducted with carbaryl, copper, 4-nonylphenol, pentachlorophenol, and permethrin in accorda...