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Seasonal changes in the tolerance of osmotic stress in natterjack toads (Bufo calamita).  

Science.gov (United States)

1. Bufo calamita were exposed to tap water to solutions of urea (up to 1000 mM) and NaCl (up to 250 mM). 2. The effects of season and nutrition on the adaptation to osmotic stress were studied by monitoring body mass, moulting rate, hematocrit, plasma osmolality and the plasma concentrations of urea, chloride and glucose. 3. There were marked seasonal changes in the time of survival in tap water as well as in the ability to acclimate to high concentrations of urea and NaCl. 4. The maximal concentration of urea in the plasma of starving toads was greater in winter (650 mM) than in summer (410 mM), but fed toads also reached winter levels (653 mM) during summer. 5. Salt acclimation was accompanied by urea accumulation in plasma up to 175 mM. 6. Salinities exceeding 454 mOsmol/l of NaCl were lethal. PMID:1348465

Sinsch, U; Seine, R; Sherif, N

1992-02-01

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

DEFF Research Database (Denmark)

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

Allentoft, Morten E.; Siegismund, Hans Redlef

2009-01-01

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The effects of selection, drift and genetic variation on life-history trait divergence among insular populations of natterjack toad, Bufo calamita.  

Science.gov (United States)

Although loss of genetic variation is frequently assumed to be associated with loss of adaptive potential, only few studies have examined adaptation in populations with little genetic variation. On the Swedish west coast, the northern fringe populations of the natterjack toad Bufo calamita inhabit an atypical habitat consisting of offshore rock islands. There are strong among-population differences in the amount of neutral genetic variation, making this system suitable for studies on mechanisms of trait divergence along a gradient of within-population genetic variation. In this study, we examined the mechanisms of population divergence using Q(ST)-F(ST) comparisons and correlations between quantitative and neutral genetic variation. Our results suggest drift or weak stabilizing selection across the six populations included in this study, as indicated by low Q(ST)-F(ST) values, lack of significant population x temperature interactions and lack of significant differences among the islands in breeding pond size. The six populations included in this study differed in both neutral and quantitative genetic variation. Also, the correlations between neutral and quantitative genetic variation tended to be positive, however, the relatively small number of populations prevents any strong conclusions based on these correlations. Contrary to the majority of Q(ST)-F(ST) comparisons, our results suggest drift or weak stabilizing selection across the examined populations. Furthermore, the low heritability of fitness-related traits may limit evolutionary responses in some of the populations. PMID:20465584

Rogell, Björn; Eklund, Martin; Thörngren, Hanna; Laurila, Anssi; Höglund, Jacob

2010-06-01

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Drift rather than selection dominates MHC class II allelic diversity patterns at the biogeographical range scale in natterjack toads Bufo calamita.  

Science.gov (United States)

Study of major histocompatibility complex (MHC) loci has gained great popularity in recent years, partly due to their function in protecting vertebrates from infections. This is of particular interest in amphibians on account of major threats many species face from emergent diseases such as chytridiomycosis. In this study we compare levels of diversity in an expressed MHC class II locus with neutral genetic diversity at microsatellite loci in natterjack toad (Bufo (Epidalea) calamita) populations across the whole of the species' biogeographical range. Variation at both classes of loci was high in the glacial refugium areas (REF) and much lower in postglacial expansion areas (PGE), especially in range edge populations. Although there was clear evidence that the MHC locus was influenced by positive selection in the past, congruence with the neutral markers suggested that historical demographic events were the main force shaping MHC variation in the PGE area. Both neutral and adaptive genetic variation declined with distance from glacial refugia. Nevertheless, there were also some indications from differential isolation by distance and allele abundance patterns that weak effects of selection have been superimposed on the main drift effect in the PGE zone. PMID:24937211

Zeisset, Inga; Beebee, Trevor J C

2014-01-01

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Phenotypic selection in common toad (Bufo bufo  

Directory of Open Access Journals (Sweden)

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.

Cvetkovi? Dragana

2007-01-01

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

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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.

Slater F.

2002-04-01

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Bufo canorus Camp 1916, Yosemite Toad.  

Science.gov (United States)

Yosemite toads (Bufo canorus) are endemic to the Sierra Nevada, California, from Ebbetts Pass, Alpine County to the Spanish Mountain area, Fresno County (Karlstrom 1962, 1973; Stebbins 1966; unpublished Sierra National Forest survey data, 1995, 2002). Sites occur from 1,950–3,444 m elevation, with the majority of sites between 2,590–3,048 m (Karlstrom, 1962). Jennings and Hayes (1994a) estimate that populations have disappeared from 50% of historically reported sites, although the overall range of the species may have only contracted in the far north and in western Fresno County. Disappearances have been concentrated at lower elevation sites on the western edge of the range, with greater persistence at higher elevation sites (Davidson et al., 2002).

Davidson, Carlos; Fellers, Gary, M.

2005-01-01

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Migrating common toads (Bufo bufo) in rural temperate regions: reservoirs of Salmonella?  

Science.gov (United States)

Salmonella infections in amphibians are supposedly highly prevalent. Migrating common amphibian species in cultivated areas such as common toads (Bufo bufo) may thus promote spread and zoonotic transfer of Salmonella to humans, both indirectly by crop and livestock contamination and by direct contact. Between February and April 2011, the intestinal content of 1,740 samples of road-killed migrating common toads in five Flemish provinces of Belgium was examined for the presence of Salmonella using bacterial culture and PCR. All the samples were negative. These results suggest that the role of migrating common toads in maintaining the infection cycle of Salmonella in northern European temperate regions is negligible. PMID:24499330

Sharifian-Fard, Mojdeh; Pasmans, Frank; Martel, An

2014-04-01

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Sumithion Induced Hepatic Injury in the Toads Bufo tibamicus  

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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 .

S. A. Sakr

2000-01-01

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

Science.gov (United States)

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…

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

2006-01-01

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Leptospires in the marine toad (Bufo marinus) on Barbados.  

Science.gov (United States)

Leptospires were isolated from the kidneys of four of 211 toads (Bufo marinus) caught on Barbados. Two of the isolates were identified as Leptospira interrogans serovar bim in the Autumnalis serogroup (the most common cause of leptospiral illness on Barbados), and two as possibly new serovars in the Australis serogroup. Sera from 198 of the toads were examined by the leptospire microscopic agglutination test. Forty-two (21%) were positive at titers of greater than or equal to 1:100, and 54 (27%) at greater than or equal to 1:50. The predominating serogroups were Australis (50%), Autumnalis (23%) and Panama (13%). The agglutination tests on the culture-positive toads showed that serologic studies alone may be of limited value in these animals. Bufo marinus can harbor pathogenic leptospires, and it may be a significant source of the Autumnalis serogroup infections in the Caribbean. PMID:3373639

Everard, C O; Carrington, D; Korver, H; Everard, J D

1988-04-01

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An Extraordinary New Toad (Bufo) ttom Costa Rica  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 di...

Savage, Jay M.

2002-01-01

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Evaluating factors affecting amphibian mortality on roads: the case of the Common Toad Bufo bufo, near a breeding place  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Common Toad Bufo bufo is the amphibian with the highest rates of road mortality in many European countries. This elevated incidence of road kills has frequently been associated with migration to breeding sites. In this study, we analysed the mortality of the Common Toad in the road network in Catalonia (NE Spain), and investigated the related causative factors on four roads near a breeding site in the Pyrenees. Results suggest that the high mortality rate is due to a combination of factor...

Garriga, N.; Franch, N.; Carretero, M. A.; Montori, A.; Llorente, G. A.; Santos, X.; Richter–boix, A.

2007-01-01

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Membrane currents in the oocyte of the toad Bufo arenarum.  

Science.gov (United States)

The amphibian oocyte cell model is widely used for heterologous expression of ionic channels and receptors. Little is known, however, about the physiology of oocyte cell models other than Xenopus laevis. In this study, the two-electrode voltage clamp technique was used to assess the most common electrical patterns of oocytes of the South American toad Bufo arenarum. Basal membrane resistance, resting potential, and ionic currents were determined in this cell model. The oocyte transmembrane resistance was 0.35 M(Omega), and the resting potential in normal saline was about -33 mV with a range between -20 mV and -50 mV. This is, to our knowledge, the first attempt to begin an understanding of the ion transport mechanisms of Bufo arenarum oocytes. This cell model may provide a viable alternative to the expression of ion channels, in particular those endogenously observed in Xenopus laevis oocytes. PMID:11857475

Kotsias, Basilio A; Damiano, Alicia E; Godoy, Sebastian; Assef, Yanina; Ibarra, Cristina; Cantiello, Horacio F

2002-03-01

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

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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.

Fernández-Palacios, O´Connor, Rocío

2009-04-01

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Abundance and Breeding Migration of the Asian Toad (Bufo gargarizans  

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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.

Sung, Hacheol

2007-11-01

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Diazinon mediated biochemical changes in the African toad (Bufo regularis  

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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.

Uche Ochei

2012-12-01

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Predation by Oregon spotted frogs (Rana pretiosa) on Western toads (Bufo boreas) in Oregon, USA  

Science.gov (United States)

Toads of the genus Bufo co-occur with true frogs (family Ranidae) throughout their North American ranges. Yet, Bufo are rarely reported as prey for ranid frogs, perhaps due to dermal toxins that afford them protection from some predators. We report field observations from four different localities demonstrating that Oregon spotted frogs (Rana pretiosa) readily consume juvenile western toads (Bufo boreas) at breeding sites in Oregon. Unpalatability thought to deter predators of selected taxa and feeding mode may not protect juvenile stages of western toads from adult Oregon spotted frogs. Activity of juvenile western toads can elicit ambush behavior by Oregon spotted frog adults. Our review of published literature suggests that regular consumption of toadlets sets Oregon spotted frogs apart from most North American ranid frogs. Importance of the trophic context of juvenile western toads as a seasonally important resource to Oregon spotted frogs needs critical investigation.

Pearl, Christopher A.; Hayes, M.P.

2002-01-01

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An Extraordinary New Toad (Bufo) ttom Costa Rica  

Scientific Electronic Library Online (English)

Full Text Available SciELO Costa Rica | Language: English Abstract in spanish Se 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 m [...] achos 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 Abstract in english 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 sol [...] id 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 discussed

Jay M, Savage.

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An Extraordinary New Toad (Bufo ttom Costa Rica  

Directory of Open Access Journals (Sweden)

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

Jay M Savage

2002-06-01

 
 
 
 
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An Extraordinary New Toad (Bufo) ttom Costa Rica  

Scientific Electronic Library Online (English)

Full Text Available SciELO Costa Rica | Language: English Abstract in spanish Se 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 m [...] achos 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 Abstract in english 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 sol [...] id 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 discussed

Jay M, Savage.

2002-06-01

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Accumulation and depuration of trace metals in Southern Toads, Bufo Terrestris, exposed to coal combustion waste  

Energy Technology Data Exchange (ETDEWEB)

Accumulation and depuration of metals by an organism are underrepresented in the literature. We collected southern toads (Bufo terrestris) from coal by-product (ash)-contaminated and uncontaminated sites to examine metal concentrations over time. Toads were placed in four exposure regimes, then sacrificed periodically over a 5-month period, and whole-body metal levels were measured. Toads exposed to ash accumulated significant concentrations of metals. Metal concentrations changed throughout the experiment, and profiles of accumulation and depuration differed depending on the metal and exposure regime. Ash-exposed toads exhibited elevated levels of 11 of 18 metals measured. Increases ranged from 47.5% for Pb to more than 5000% for As. Eight of 18 metals did not change in control toads, while 10 of 18 metals decreased in toads removed from ash, ranging from -25% for Co to -96% for Tl. Seven metals that decreased in toads removed from ash did not change in control toads.

Ward, C.; Hassan, S.; Mendonca, M. [Auburn University, Auburn, AL (United States). Dept. of Biological Science

2009-02-15

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

Science.gov (United States)

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 [P<0.05] reduced the mean twitch height from 2.62 cm to 1.0 cm and mean peak tetanic height from 5.38 cm to 4.32 cm. Hexamethonium, however does not produce tetanic fade at the same concentration. We hypothesized that the cholinoceptors of the neuromuscular junction of the common African toad (Bufo regularis) resemble the developing synapse of African clawed toad (Xenopus laevis) and may contain muscarinic M1 autoreceptors at the pre juntional membrane. PMID:20234748

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

2009-12-01

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

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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

?a?enovi? Natalija

2013-01-01

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

Science.gov (United States)

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...

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POPULATION STRUCTURE OF THE RED-SPOTTED TOAD, BUFO PUNCTATUS, IN A NATURALLY FRAGMENTED DESERT LANDSCAPE  

Science.gov (United States)

We investigated the spatial scale at which genetic structure of Bufo punctatus within the Mojave Desert is organized by sequencing a portion of mitochondrial DNA control region for 831 toads collected from 43 sites around Las Vegas, Nevada. We grouped these collecti...

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

Science.gov (United States)

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

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Digitalis-like compounds in the toad Bufo viridis: interactions with plasma proteins.  

Science.gov (United States)

Digitalis-like compounds (DLC), normal constituents of animal tissues, are possible regulators of the Na+,K(+)-ATPase implicated in water and salt homeostasis. DLC are present in toad (Bufo viridis) tissues. Although DLC highest levels were found in toad skin, it was also detected in plasma and many internal organs. The abundant distribution and the different levels of DLC in various tissues exclude the possibility that toxicity is the only function of these compounds in the toad. The concentration of DLC in toad plasma is 30 microM, out of which 25-30% is bound to plasma proteins. Fractionation of toad plasma proteins on a G-100 Sephadex column followed by the extraction of DLC from the plasma proteins revealed that DLC are bound primarily to proteins of 48,000-53,000 Da. These results establish the existence of bufodienolide-binding protein(s) in animal plasma. PMID:7508011

Lichtstein, D; Gati, I; Ovadia, H

1993-01-01

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Rhabdias pseudosphaerocephala infection in Bufo marinus: lung nematodes reduce viability of metamorph cane toads.  

Science.gov (United States)

Cane toads (Bufo marinus) were introduced to Australia in 1935 and have since spread widely over the continent, generating concern regarding ecological impacts on native predators. Most Australian cane toad populations are infected with lung nematodes Rhabdias pseudosphaerocephala, a parasite endemic to New World (native-range) cane toad populations; presumably introduced to Australia with its toad host. Considering the high intensities and prevalence reached by this parasite in Australian toad populations, and public ardour for developing a control plan for the invasive host species, the lack of experimental studies on this host-parasite system is surprising. To investigate the extent to which this lungworm influences cane toad viability, we experimentally infected metamorph toads (the smallest and presumably most vulnerable terrestrial phase of the anuran life cycle) with the helminth. Infected toads exhibited reduced survival and growth rates, impaired locomotor performance (both speed and endurance), and reduced prey intake. In summary, R. pseudosphaerocephala can substantially reduce the viability of metamorph cane toads. PMID:19523249

Kelehear, C; Webb, J K; Shine, R

2009-07-01

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

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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.

EVELYN L. BULL

2006-09-01

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[Polyploidy and deviations in the gonadal morphology of tetraploid toads, Bufo danatensis (Amphibia: Anura: Bufonidae)].  

Science.gov (United States)

Morphological features of gonads of diploid Bufo viridis and tetraploid B. danatensis from 15 localities of USSR (453 spec.) were investigated. Females with the rudimentary ovaries were found among polyploid toads from south Turkmenia. The toads from Tajikistan having the external features of males usually demonstrated a specific kind of lateral gynandromorphism: a single side testes and rudimentary ovaries (with the normal ovarioles). The observed facts are treated either as a result of hybridization of recent species or as a result of originality of genomes organization. PMID:1292159

Pisanets, E M

1992-01-01

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Experimental repatriation of boreal toad (Bufo boreas) eggs, metamorphs, and adults in Rocky Mountain National Park  

Science.gov (United States)

The boreal toad (Bufo boreas) is an endangered species in Colorado and is considered a candidate species for federal listing by the United States Fish and Wildlife Service. Boreal toads are absent from many areas of suitable habitat in the Southern Rocky Mountains of Colorado presumably due to a combination of causes. We moved boreal toads from existing populations and from captive rearing facilities to habitat which was historically, but is not currently, occupied by toads to experimentally examine methods of repatriation for this species. Repatriation is defined as the release of individuals into areas currently of historically occupied by that species (Dodd and Seigel, 1991). This effort was in response to one of the criteria for delisting the boreal toad in Colorado stated in the conservation plan and agreement for the management and recovery of the Southern Rocky Mountain population of the boreal toad (Loeffler, 1998:16); a??a?|there must be at least 2 viable breeding populations of boreal toads in each of at least 9 of 11 mountain ranges of its historic distribution.a?? Without moving eggs from established wild populations, or from captivity to historical localities, it is doubtful whether the recovery team will attain this ambitions goal.

Muths, E.; Johnson, T.L.; Corn, P.S.

2001-01-01

33

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

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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.

Roberto Alonso

2003-12-01

34

Glyconeogenesis and urea synthesis in the toad Bufo viridis during acclimation to water restriction.  

Science.gov (United States)

Metabolic consequences of osmotic stress were investigated in the toad Bufo viridis. Toads were acclimated either to terrestrial conditions in the absence of free water or to being partially immersed in 250 mmol L-1 NaCl, which was achieved by gradually increasing the salinity of the bath. This slow acclimation evoked little metabolic response, whereas the immediate osmotic challenge of water restriction resulted in a significant increase in the concentration of urea in the plasma and in liver glycogen. Urea accumulation, involving a transient increase in its rate of synthesis, allows the toads to lower their body water potential and thereby to absorb soil-bound water. The metabolic cost of this response is reduced by conserving the resulting by-product, glucose, as glycogen stored in the liver for future use. PMID:9472816

Hoffman, J; Katz, U

1998-01-01

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Chemopreventive effects of cabbage on 7,12-dimethylbenz(a)-anthracene-induced hepatocarcinogenesis in toads (Bufo viridis).  

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Hepatocellular carcinoma was induced in the toad, Bufo viridis, in 29 out of 100 cases by the administration of 0.5 mg of 7,12-dimethylbenz(a)anthracene (DMBA)/toad, 3 times/week for 12 weeks. In contrast, toads treated with DMBA and cabbage diet 1 or 2 ml (3 h prior to the carcinogen)/toad, every day for 12 weeks showed a lower incidence of liver tumors: 15 and 12 cases out of 100. However, cabbage diet (2 ml/toad, every day for 12 weeks) was ineffective when administered 3 h after the carcinogen (DMBA) in 27 out of 100 cases. Neither tumor growth nor neoplastic changes were observed in toads treated with olive oil alone or with cabbage diet. It is concluded that a cabbage diet during initiation has an inhibitory effect on hepatocarcinogenesis in toads. PMID:7616322

Sadek, I; Abdel-Salam, F; al-Qattan, K

1995-02-01

36

Auxetic Growth in the Javanese Toad, Bufo melanostictus.  

Science.gov (United States)

Morphologically, it has been found that erythrocyte size in the Javanese toad is greater in large than in small animals, and preliminary data indicate that the same is true of kidney, intestinal, and liver cells. Physiologically, the hemoglobin concentration, packed cell volume, specific gravity of the whole blood, and the liver glycogen concentration also increase with the size of the animals. PMID:17754653

Church, G

1961-06-23

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In vitro cardiotoxicity and mechanism of action of the Egyptian green toad Bufo viridis skin secretions.  

Science.gov (United States)

Amphibian skin secretions are considered a rich source of biologically active compounds and are known to be rich in bufadienolides, peptides and alkaloids. Bufadienolides are cardioactive steroids derived from animals and plants as well. The current study was conducted to investigate the influence of skin secretions of the Egyptian green toad Bufo viridis (SSBV) on the cardiac electrical activity. Isolated toad's heart was used to reveal the mechanism of action. Application of SSBV (40microg/ml) into isolated toad's heart significantly decreased the heart rate (HR) accompanied by an elongation in the conduction time (P-R interval). A pronounced increase of the ventricular contraction (R-wave amplitude) was observed after SSBV application. Marked electrocardiographic changes were induced within minutes (5-20min) of SSBV perfusion of the isolated hearts; such as sinus arrhythmias, junctional ectopic beats, negative QRS deflection, ventricular tachycardia and heart block. The mechanism of action of SSBV was studied by direct application of different autonomic and ion channels antagonists (atropine sulphate, propranolol and verapamil) to isolated toad's heart. Neither atropine nor verapamil could attenuate the noticed negative chronotropic and positive inotropic effects. Meanwhile, post-treatment with propranolol decreased R-wave amplitude. Taken together, it can be concluded that: (i) SSBV has a negative chronotropic, dromotropic and positive inotropic effects on isolated toad's heart; (ii) the reported effects of SSBV could be due to inhibition of Na(+)-K(+) ATPase and through ss-adrenergic receptors. PMID:19825411

Abdel-Rahman, Mohamed A; Ahmed, Sherifa Hamid; Nabil, Zohour I

2010-03-01

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Effects of spirotetramat on the acute toxicity, oxidative stress, and lipid peroxidation in Chinese toad (Bufo bufo gargarizans) tadpoles.  

Science.gov (United States)

The aim of this work was to evaluate the potential effects of antioxidant and lipid peroxidation parameters as indicators of exposure to spirotetramat and effects of acute toxicity in the Chinese toad Bufo bufo gargarizans. The results of an acute toxicity test showed that the 72 and 96 h median lethal concentrations (LC(50)) of spirotetramat for tadpoles were 6.98 and 6.45 mg/L, respectively. It indicated that the spirotetramat was moderate toxicity to Chinese toad tadpoles. In a sub-lethal toxicity test, the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) contents were determined after exposure to 0.03, 0.06, 0.13, 0.65, and 3.23 mg/L for 4, 15, and 30 days. SOD activity significantly in all experimental groups except the highest concentration group increased on day 4 but decreased on days 15 compared with that of the acetone control (P < 0.05). The most sensitive parameters was GSH-Px activity, which significantly increased on day 4, but was inhibited and decreased after prolonged exposure for 15 and 30 days except the lowest concentration treatment group (P < 0.05). The MDA content significantly decreased on day 30 (P < 0.05). During the entire experimental period, sub-lethal doses spirotetramat caused oxidative stress and lipid peroxidation in B. gargarizans tadpoles. These results indicate that sub-lethal even non-lethal spirotetramat are potentially toxic to amphibians. The information presented in this study will be helpful for understanding oxidative stress induced by spirotetramat in aquatic organisms. PMID:24835551

Yin, XiaoHui; Jiang, ShengJu; Yu, Jun; Zhu, GuoNian; Wu, HuiMing; Mao, ChenLei

2014-05-01

39

Taxonomy and distribution of the South American toad Bufo poeppigii Tschudi, 1845 (Amphibia, Anura, Bufonidae  

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Full Text Available The taxonomic status of the Andean toad Bufo poeppigii has been controversial since its description by Tschudi in the 19th Century, because of the similar appearance of the species with respect to Bufo marinus, and the fact that both species may occur together in some localities at the foot of the Andes. Bufo poeppigii is a valid species occurring on the Amazonian slopes of the Andes, at least from central Bolivia to northern Peru. It differs from B. marinus mainly by a less marked sexual dimorphism in size, smaller size, rugose skin always present in males, distribution of nuptial excrescences, and some features of the parotoid glands. The variability of B. marinus encompasses that of B. poeppigii; thus, in some cases it is difficult to identify some specimens.La posición taxonómica del sapo andino Bufo poeppigii ha sido objeto de controversia desde su descripción por Tschudi en el siglo XIX. Ello se ha debido a su parecido con Bufo marinus y a que ambas especies pueden encontrarse juntas en algunas localidades del piedemonte andino. No obstante, Bufo poeppigii es una especie válida que habita en las laderas amazónicas andinas, al menos desde el centro de Bolivia hasta el norte de Perú. Difiere de B. marinus por tener dimorfismo sexual en tamaño menos marcado, menor talla, piel siempre rugosa en los machos, la distribución de las callosidades nupciales y algunos rasgos de las glándulas parotoides. La variabilidad de B. marinus abarca la de B. poeppigii, de modo que a veces es difícil identificar ciertos ejemplares.

De la Riva, Ignacio

2002-06-01

40

[A shift in prey color preference in the green toad Bufo viridis Laur. after food satiation].  

Science.gov (United States)

In the behavioural experiments when showing simultaneously coloured stimuli (food targets) and also in choosing between two stimuli, red and blue, it had been shown with a high level of reliability that the hungry Bufo viridis which had not been fed for at least a week, in the overwhelming majority of cases chose the red-coloured food targets. Within 1-3 days after an abundant feeding, in the same animals the changes occurred in their preferences of the prey colour. The percentage of choosing the blue targets by the satiated toads significantly increases. In a separate series of experiments had been demonstrated that the changing motivation is conditioned by colour, since hungry and satiated Bufo viridis under conditions of simultaneous demonstration of four stimuli, black and three different grey stimuli, chose exclusively the black stimulus. PMID:10368629

Fal'tsman, I A; Bastakov, V A

1999-01-01

 
 
 
 
41

[Cardiotropic activity of total bufadienolides from the poison of Central Asian toad Bufo viridis].  

Science.gov (United States)

The sum of bufadienolides (bacagin) isolated from the poison of Bufo viridis toad occurring in Central Asia produces a selective strophanthin-K-like action upon the heart function, increasing myocardial contractility, retarding cardiac rhythm, and positively influencing the parameters of myocardial metabolism. The mechanism of realization of the positive ionotropic effect of bacagin is probably related to the ability of increasing the basal level of cytosol calcium at the expense of inhibiting the activity of Na+/K(+)-ATPase and, to some extent, Ca(2+)-ATPase in endoplasmic reticulum. PMID:12449070

Usanova, I V; Khushbaktova, Z A; Syrov, V N; Azizov, D E; Mirzaakhmedov, Sh Ia; Soliev, A B; Tashmukhamedov, M S; Salikhov, Sh I

2002-01-01

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

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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.

S. A. Sakr

2002-01-01

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A sexual dimorphism of the harderian gland of the toad, Bufo viridis.  

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The Harderian gland of the toad, Bufo viridis, is an acinar gland located at the medial corner of the orbit. The columnar glandular cells show considerable variation in height depending upon their functional state. During July they are taller than in November and May, and filled with secretory seromucous granules. The glandular cells of the female toad, only, contain at their base numerous lipid droplets dispersed in a smooth endoplasmic reticulum. This is the first observation of sexual dimorphism in the Harderian gland of a nonmammalian vertebrate. The secretion of the gland is mainly merocrine. Although the secretion of the Harderian gland is mainly concerned with lubrication of the eyeball, the presence of lipid secretion only in the female glandular cells suggests a pheromonale function, which may influence the sexual behaviour of the male. PMID:2629703

Minucci, S; Baccari, G C; Di Matteo, L; Chieffi, G

1989-01-01

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Evaluation of DNA damage in Chinese toad (Bufo bufo gargarizans) after in vivo exposure to sublethal concentrations of four herbicides using the comet assay.  

Science.gov (United States)

Chinese toad, Bufo bufo gargarizans, is frequently found in rice fields, muddy ponds, wetlands and other aquatic ecosystems in China. Because of its habitat, it has many chances of being exposed to pesticides, such as acetochlor, butachlor, chlorimuron-ethyl, and paraquat, which are extensively used in rice or cereal fields. Amphibians may serve as model organisms for determining the genotoxic effects of pollutants contaminating these areas. In the present study DNA damage was evaluated in the Chinese toad using the comet assay, as a potential tool for the assessment of ecogenotoxicity. The first step was to determine the acute toxicity of the above-mentioned herbicides. In acute tests, tadpoles were exposed to a series of relatively high concentrations of acetochlor, butachlor, chlorimuron-ethyl, and paraquat for 96 h. The LC(50 )(96 h) of acetochlor, butachlor, chlorimuron-ethyl and paraquat were measured as 0.76, 1.32, 20.1 and 164 mg l(-1), respectively. Also, negative effects on the behavior of tadpoles were observed with acetochlor, butachlor, and paraquat. Secondly, the comet assay was used for detecting DNA damage in Chinese toad tadpoles exposed to sublethal concentrations of four herbicides. Significant (P butachlor, paraquat, and methyl methanesulfonate, except chlorimuron-ethyl. To our knowledge, this is the first report describing the use of Bufo bufo gargarizans for genotoxicity assessment of herbicides. PMID:18297398

Yin, Xiao Hui; Li, Shao Nan; Zhang, Le; Zhu, Guo Nian; Zhuang, Hui Sheng

2008-05-01

45

Purification of toad (Bufo japonicus) gonadotropins and development of their homologous radioimmunoassays  

International Nuclear Information System (INIS)

We obtained three gonadotropin fractions with different electrophoretic mobilities named B1D, B3D and B5D from a glycoprotein fraction of toad (Bufo japonicus) pituitaries by cation exchange chromatography using the fast protein liquid chromatography (FPLC) system, chromatofocusing and gel filtration using the FPLC system. Gonadotropin activity was monitored by two radioreceptor assay (RRA) systems, one using bullfrog testis and bullfrog LH as the source of receptor and radioligand respectively, and the other using toad testis and bullfrog FSH respectively. Although, LH/FSH specificity was not complete in these RRAs, the fraction BID showed a higher potency in LH-RRA than in FSH-RRA, while B3D and B5D showed lower potencies in LH-RRA activity than in FSH-RRA. Furthermore, B1D had an activity to release androgen from the toad testis, while B3D and B5D had slight activities. All these fractions stimulated accumulation of cAMP in testis slices of the toad in vitro. These results suggest that B1D contains LH, and B3D and B5D contain FSH-like gonadotropin. SDS PAGE analysis in combination with immunoblot revealed that B1D was almost pure LH, but B3D seemed to be not homogeneous. Anti-B1D-serum and anti-B3D-serum were raised in rabbits, and radioimmunoassays (RIAs) for B1D and B3D were established. The cross reactivity of B3D and B5D in B1D-RIA was about 30% of B1D, while that of B1D in B3D-RIA was only 3% of B3D and B5D. These RIAs were sensitive enough to measure gonadotr were sensitive enough to measure gonadotropins in plasma samples of Bufo japonicus. (author)

46

Purification of toad (Bufo japonicus) gonadotropins and development of their homologous radioimmunoassays  

Energy Technology Data Exchange (ETDEWEB)

We obtained three gonadotropin fractions with different electrophoretic mobilities named B1D, B3D and B5D from a glycoprotein fraction of toad (Bufo japonicus) pituitaries by cation exchange chromatography using the fast protein liquid chromatography (FPLC) system, chromatofocusing and gel filtration using the FPLC system. Gonadotropin activity was monitored by two radioreceptor assay (RRA) systems, one using bullfrog testis and bullfrog LH as the source of receptor and radioligand respectively, and the other using toad testis and bullfrog FSH respectively. Although, LH/FSH specificity was not complete in these RRAs, the fraction BID showed a higher potency in LH-RRA than in FSH-RRA, while B3D and B5D showed lower potencies in LH-RRA activity than in FSH-RRA. Furthermore, B1D had an activity to release androgen from the toad testis, while B3D and B5D had slight activities. All these fractions stimulated accumulation of cAMP in testis slices of the toad in vitro. These results suggest that B1D contains LH, and B3D and B5D contain FSH-like gonadotropin. SDS PAGE analysis in combination with immunoblot revealed that B1D was almost pure LH, but B3D seemed to be not homogeneous. Anti-B1D-serum and anti-B3D-serum were raised in rabbits, and radioimmunoassays (RIAs) for B1D and B3D were established. The cross reactivity of B3D and B5D in B1D-RIA was about 30% of B1D, while that of B1D in B3D-RIA was only 3% of B3D and B5D. These RIAs were sensitive enough to measure gonadotropins in plasma samples of Bufo japonicus. (author).

Takada, Koji; Itoh, Masanori; Nishio, Hiroshi; Ishii, Susumu (Waseda Univ., Tokyo (Japan))

1989-10-01

47

Diagnostic histological findings in Yosemite toads (Bufo canorus) from die-off in the 1970s  

Science.gov (United States)

Twelve adult and 25 larval Yosemite toad (Bufo canorus) specimens from the eastern Sierra Nevada of California were examined histologically for evidence of infectious, toxicological, and degenerative diseases. The preserved toads were selected from 21 that had been salvaged or collected during a die-off in 1976-1979 that immediately preceded a population decline. Causes of death of four toads were determined histologically; clinical signs and field observations suggested causes of death of three more. Four toads died of infectious diseases, including chytridiomycosis of the skin (N = 1), bacillary septicemia (N = 2), and combined chytridiomycosis and bacterial septicemia (N = 1). Infections by a funguslike organism (Dermosporidium penneri), renal myxozoa (Leptotheca ohlmacheri), larval Rhabdias, various gastrointestinal nematodes, urinary bladder flukes, and lung flukes were detected in five specimens. No evidence of degenerative diseases, virus infections, or intoxications was found. The variety of lethal diseases and our inability to determine the causes of death of five specimens suggests that one or more histologically undetectable diseases or intoxications may have also contributed to the deaths and population decline.

Green, D.E.; Sherman, C.K.

2001-01-01

48

Sexual differences in the post-breeding movements and habitats selected by Western toads (Bufo boreas) in southeastern Idaho  

Science.gov (United States)

We used radio-telemetry to study the movements and habitat use of Western toads (Bufo boreas) in the Targhee National Forest in southeastern Idaho. Eighteen toads (10 male and 8 female) that bred in a seasonally flooded pond, were fitted with radio-transmitters, tracked, and their movements mapped and analyzed with global positioning and geographic information systems. We also analyzed their patterns of habitat selection at micro- and macro-scales by comparing sites used by toads with randomly selected sites. After breeding, two male and six female toads left the breeding pond and used terrestrial habitats extensively. Male and female toads showed different patterns of movement and habitat use, although all toads seemed to behave in ways that reduced loss of body water (e.g., such as traveling on nights of high humidity). Male toads traveled shorter distances from the pond than females (581 ?? 98 m and 1105 ?? 272 m, respectively). Female toads used terrestrial habitats extensively and were selective of cover types (e.g., shrub) that provided greater protection from dehydration. Female toads also preferred certain habitat edges and open forests over forests with closed canopies or clearcuts. Information from this study can assist land managers in establishing protective buffers and managing forests for the protection of toad populations.

Bartelt, P.E.; Peterson, C.R.; Klaver, R.W.

2004-01-01

49

Origin of the parasites of an invading species, the Australian cane toad (Bufo marinus): are the lungworms Australian or American?  

Science.gov (United States)

Phylogeographical analyses that identify the geographical origin of parasites in invading species can clarify the parasites' potential for biological control of the invader and the risks posed by the parasite to native species. Our data on nuclear and mitochondrial genetic sequences show that the nematode lungworms (Rhabdias spp.) in invasive Australian populations of cane toads (Bufo marinus) are Rhabdias pseudosphaerocephala, a South American species. We did not find this lungworm species in any Australian frogs sympatric with cane toads, suggesting that the parasite does not attack Australian frogs and hence may offer potential as a biocontrol agent of the toad. PMID:18803593

Dubey, Sylvain; Shine, Richard

2008-10-01

50

A note on asymmetric use of the forelimbs during feeding in the European green toad (Bufo viridis).  

Science.gov (United States)

European green toads (Bufo viridis) were tested for one-sided forelimb lateralisation during prey ingestion, i.e., when pushing food into the mouth. Results showed that toads preferentially used their left forelimb to help themselves in the ingestion of living larvae. It is argued that previous failure to reveal lateralisation in tests in which B. viridis toads wiped a foreign object off their snout was due to prevalent activation of grooming behaviour; in contrast, lateralisation seems clear when specifically associated with feeding behaviour. PMID:17712715

Sovrano, Valeria Anna

2007-09-01

51

[Changes in heat resistance of the muscle and glycerinated muscle fibers of green toad (Bufo viridis complex)].  

Science.gov (United States)

Heat resistance of muscles and actomyosin proteins was determined at damaging temperatures of 41, 42, and 43 degrees C in three green toad (Bufo viridis complex) populations from different climatic zones of Uzbekistan. The highest muscle and model resistance to these temperatures was revealed in toads living in the warmest plain regions of the country, while the lowest resistance was specific for animals from the piedmont and mountain regions. The variability of heat resistance of the muscle and models was also the highest in toads of the first group. Divergence going in this animal species is proposed. PMID:16004272

Pashkova, I M; Korotneva, N V; Pasynkova, R A

2005-01-01

52

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

Science.gov (United States)

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

53

[Differences in muscle thermostability between diploid and tetraploid species of green toads (Bufo viridis complex) of Middle Asia].  

Science.gov (United States)

Significant differences were found between diploid (Bufo viridis) and tetraploid (B. danatensis) toad species in their skeletal muscle thermostability. The lower muscle thermostability in tetraploids may be associated with the adaptation of B. danatensis to colder conditions of arid mountain area in the Middle Asia. PMID:12094763

Borkin, L Ia; Pashkova, I M; Litvinchuk, S N

2002-01-01

54

Experimental population dynamics of Rhabdias bufonis (Nematoda) in toads (Bufo bufo): density-dependence in the primary infection.  

Science.gov (United States)

Density-dependence in worm establishment, numbers, biomass and larval production were examined in primary infections of 0, 10, 40, 80 and 160 larvae of the lung nematode, Rhabdias bufonis in the common toad, Bufo bufo. The infection procedure established 4 non-overlapping levels of infection which persisted until 6 weeks post-infection (p.i.), after which there was an overall decline up to 12 weeks p.i. Worm numbers had no direct effect on adult worm survival but temporal changes in worm weight were density-dependent. Adult worm establishment in the lungs declined significantly as the numbers of worms in the lungs increased. At the lowest exposure dose, 86% of the larvae administered reached maturity in the lungs while at the highest, only 37% did so. Also, the numbers of immature larvae outside the lungs increased as adult worm numbers increased. Both features provide evidence for a threshold limit to the numbers of worms maturing in the lungs. Worm numbers also affected larval output per host and per capita fecundity. A significant positive relationship between per capita fecundity and per capita worm weight suggested that density-dependence acted primarily to constrain the growth of individual worms. Finally, the constraints imposed on worm growth and fecundity were apparently relaxed when worm density decreased, providing evidence for density-dependent flexibility in per capita fecundity. Density-dependence in worm establishment and per capita fecundity are mechanisms which may potentially regulate this host-parasite interaction in the field. Both mechanisms may be functionally related to physical space limitations in the lungs, within which worms must compete for finite nutrients. PMID:1614734

Goater, C P

1992-02-01

55

Efficacy of fenbendazole and levamisole treatments in captive Houston toads (Bufo [Anaxyrus] houstonensis).  

Science.gov (United States)

Effective disease monitoring and prevention is critical to the success of captive amphibian care. Nematodes, including the genera Rhabdias and Strongyloides, are known to contribute to mortality in captive amphibians and have been identified in the Houston Zoo's endangered Houston toad (Bufo [Anaxyrus] houstonensis) captive assurance colony. Five years of fecal data for the toad colony were compiled and analyzed in order to investigate the efficacy of two anthelminthic medications, fenbendazole (FBZ) and levamisole (LMS), which were used to control nematode infections. Both FBZ (dusted onto food items) and topical LMS (6.5 to 13.5 mg/kg) significantly reduced the number of nematode eggs, larvae, and adults observed by fecal parasitologic examination. There were no significant differences between treatments, and egg reappearance periods were difficult to compare as a result of low sample size. No adverse effects from either anthelminthic treatment were observed. Both topical LMS and oral FBZ appear to be safe and efficacious treatments for the reduction of the internal nematode burden in captive Houston toads. PMID:25314823

Bianchi, Catherine M; Johnson, Cassidy B; Howard, Lauren L; Crump, Paul

2014-09-01

56

Behavioral response and kinetics of terrestrial atrazine exposure in American toads (bufo americanus)  

Science.gov (United States)

Amphibians in terrestrial environments obtain water through a highly vascularized pelvic patch of skin. Chemicals can also be exchanged across this patch. Atrazine (ATZ), a widespread herbicide, continues to be a concern among amphibian ecologists based on potential exposure and toxicity. Few studies have examined its impact on the terrestrial juvenile or adult stages of toads. In the current study, we asked the following questions: (1) Will juvenile American toads (Bufo americanus) avoid soils contaminated with ATZ? (2) Can they absorb ATZ across the pelvic patch? (3) If so, how is it distributed among the organs and eventually eliminated? We conducted a behavioral choice test between control soil and soil dosed with ecologically relevant concentrations of ATZ. In addition, we examined the uptake, distribution, and elimination of water dosed with 14C-labeled ATZ. Our data demonstrate that toads do not avoid ATZ-laden soils. ATZ crossed the pelvic patch rapidly and reached an apparent equilibrium within 5 h. The majority of the radiolabeled ATZ ended up in the intestines, whereas the greatest concentrations were observed in the gall bladder. Thus, exposure of adult life stages of amphibians through direct uptake of ATZ from soils and runoff water should be considered in risk evaluations. ?? 2009 Springer Science+Business Media, LLC.

Storrs, Mendez, S. I.; Tillitt, D. E.; Rittenhouse, T. A. G.; Semlitsch, R. D.

2009-01-01

57

Comparison of toad skins Bufo bufo gargarizans Cantor from different regions for their active constituents content and cytotoxic activity on lung carcinoma cell lines  

Science.gov (United States)

Background: The skin of Bufo bufo gargarizans Cantor, rich in bufadienolides, peptides, and alkaloids, has approved pharmacological activity for preliminary anti-liver and lung tumor treatment. However, few studies have systematically focused on the influence of the producing regions on the content and antitumor activity of the active constituents in toad skins. Objective: This study aims to compare toad skins obtained from six different regions in China (Jiangsu, Anhui, Henan, Hebei, Jiangxi, and Shandong province) for their bufadienolide and alkaloid content, and their cytotoxic activity on two lung carcinoma cell lines (SPC-A-1 cells and A549 cells). Materials and Methods: High performance liquid chromatography (HPLC) was used to quantificationally determine four bufadienolides, which included bufotalin, bufalin, cinobufagin, and resibufogenin in toad skins, from six different regions, respectively. In addition, an ultraviolet (UV) spectrophotometer was also employed to identify the content of the total alkaloids using 5-hydroxytryptamine (5-HT) as the reference substance. An MTT assay was performed to compare the antiproliferative effects of the toad skins’ ethanolic extracts from the different regions against SPC-A-1 and A549 cells. Results: In this study, the toad skins from Jiangsu province had the highest amount of bufadienolides (472.6 ?g/g crude drug) and alkaloids (1.51 mg/g crude drug). Meanwhile, according to the extract, it exhibited the strongest cytotoxic effect against the lung carcinoma cell line (SPC-A-1 cells and A549 cells) with IC50 values of 24.82 ± 0.76 and 23.77 ± 0.63 ?g crude drug/mL, respectively. Conclusion: The toad skins that originated from the Jiangsu province, have comparatively greater advantages over samples from other regions as far as active constituent content and potential anti-lung cancer activity is concerned, suggesting that it can be a promising chemotherapeutic agent in lung cancer therapy, in further studies.

Liu, Congyan; Cao, Wei; Chen, Yan; Qu, Ding; Zhou, Jing

2014-01-01

58

Post-breeding habitat use by adult Boreal Toads (Bufo boreas) after wildfire in Glacier National Park, USA  

Science.gov (United States)

Effects of wildfire on amphibians are complex, and some species may benefit from the severe disturbance of stand-replacing fire. Boreal Toads (Bufo boreas boreas) in Glacier National Park, Montana, USA increased in occurrence after fires in 2001 and 2003. We used radio telemetry to track adult B. boreas in a mosaic of terrestrial habitats with different burn severities to better understand factors related to the post-fire pulse in breeding activity. Toads used severely burned habitats more than expected and partially burned habitats less than expected. No toads were relocated in unburned habitat, but little of the study area was unburned and the expected number of observations in unburned habitat was toads are more likely to occupy habitats that have diverged from historic fire return intervals. Copyright ?? 2008. C. Gregory Guscio. All rights reserved.

Guscio, C. G.; Hossack, B. R.; Eby, L. A.; Corn, P. S.

2008-01-01

59

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

DEFF Research Database (Denmark)

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 steady-state conductance and the steady-state chloride current reveal that the chloride pathway has maximum conductance for V approximately -80 mV (outside of the skin being negative) and approaches a non-conducting safe for V greater than 0 mV. This strong outward going rectification is a steady-state phenomenon: In skins hyperpolarized for a few minutes, the "instantaneous" I-V curves show that the chloridepathway 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-compartment model indicate that the strong steady-state chloride current rectification cannot be obtained if only the intracellular chloride concentration and the membrane potentials are allowed to vary ("Goldman-rectification"). It is suggested, therefore, that the premeability of the chloride pathway varies reversibly with the transepithelial potential difference. The variable which controls the chloride permeability may be a membrane potential or the concentration of an intracellular ion.

Larsen, Erik Hviid; Kristensen, P

1978-01-01

60

Mucopolysaccharide histochemistry of the oviduct of the toad, Bufo melanostictus, before and during ovulation.  

Science.gov (United States)

In both non-ovulating and ovulating toads of the species, Bufo melanostictus, the fimbrium stained only weakly for mucopolysaccharides (MPs) whereas the infundibulum stained strongly for neutral MPs and also for glycogen. In the non-ovulating toad, only neutral and sulphated MPs were detected in the goblet cells of the upper magnum, whereas sulphated, neutral and sialomucins were detected in the glands. In the middle magnum, sulphated and sialic acid-containing carboxylated MPs were detected in both the goblet cells and glands. In the lower magnum, neutral, sulphated, and sialic acid-containing MPs were detected in the goblet cells and only sulphated and sialic acid-containing MPs were detected in the glands. In the isthmus and ovisac, only sulphated MPs were present in the goblet cells. During ovulation, there was no change in the distribution of sulphated MPs throughout the oviduct. Sialic acid-containing MPs could not be detected in many of the goblet cells of the upper and lower magnum nor in most of the glands of the lower magnum. PMID:7516206

Tan, C K; Chen, T W; Gan, J M

1994-01-01

 
 
 
 
61

The primary immune response of the green toad (Bufo viridis) to challenge with Crithidia fasciculata.  

Science.gov (United States)

The primary immune response of the green toad (Bufo viridis) following immunization with Crithidia fasciculata choanomastigotes was studied. Lysins, agglutinins, and antibodies detectable by enzyme-linked immunosorbent assay (ELISA) were first detected in the sera of immunized animals one week after injection. The antibody titers increased to significant levels (P less than 0.01) and maximum values were reached seven weeks post-immunization. The stimulated immunoglobulins were antigen-specific, partially heat-labile, sensitive to the reducing agent dithiothreitol, possessed precipitin activity, effectively fixed complement and exhibited an electrophoretic mobility similar to the gamma-globulins of human serum. On this basis, it is probable that the antibody produced during the primary response in green toads is high molecular weight IgM. Increases in serum lysozyme levels paralleled the rise of antibody titers. Overall, the lysozyme concentration increased two-fold compared to the appropriate controls. This is the first report of the immune response in amphibians to experimental injection with protozoan parasites and the use of the ELISA technique to detect antibodies in amphibian sera. PMID:3670126

Al-Yaman, F; Ingram, G A

1987-01-01

62

Putative L-triiodothyronine receptors in the liver nuclei of mature tropical toad, Bufo melanostictus.  

Science.gov (United States)

Thyroid hormones exert a major role in growth and differentiation of almost all types of tissues in animals, particularly in amphibian metamorphosis, through its specific nuclear receptor activation followed by gene expression. However, its function in mature tropical amphibians is less studied. The present study revealed the existence of a single class of specific nuclear receptor(s) in the liver nuclei of mature tropical toad, Bufo melanostictus, with a dissociation constant of (3.7 +/- 0.9) x 10(-10) molar and maximum binding capacity of 0.074 +/- 0.013 pmol/mg DNA. The percentage of relative binding affinities for the specific nuclear L-T3 binding site in the liver nuclei of toad were L-triiodothyronine (L-T3) > triiodothyroacetic acid (TRIAC) > L-thyroxine (L-T4) = tetraiodothyroacetic acid (TETRAC) > 3,3',5'-triiodothyronine (r-T3) > Diiodothyrtonine (L-T2) (100 > 75 > 19.4 = 19.4 > 3.7 > 0.39) and the relative ED50 values (in nanomolar) were 0.33 < 0.44 < 1.7 = 1.7 < 9 < 83. PMID:15018064

Sarkar, Pradip K; Dey, Shyam S; Koley, Biswanath; Koley, Juthika; Ray, Arun K

2004-01-01

63

The effect of aldosterone on sodium transport and membrane conductances in toad skin (Bufo viridis).  

Science.gov (United States)

The effect of aldosterone (1 mumol/l for 4-6 h) on Na+ transport across toad skin (Bufo viridis) was studied in skins preincubated in vitro. Short-circuit current (Isc) was consistently and reproducibly elevated in skins from NaCl(100 and 200 mmol/l)-acclimated toads, where the baseline Isc was greatly reduced. The effect of aldosterone was tested in NaCl and NaNO3 Ringer's and also after oxytocin (50 mU/ml) in the latter conditions. Apical membrane conductance of the principal cells increased consistently after aldosterone in all skins and was linearly correlated with the Isc under all conditions. This confirms that the stimulation of Na+ transport originates from the effect of the aldosterone on apical Na+ channels. Basolateral membrane conductance was also significantly elevated compared with control pieces in those tissues that were preincubated with aldosterone for 4-6 h. The increase, however, did not correlate with the magnitude of the Isc. It is therefore concluded that aldosterone specifically stimulates, in addition to the apical effect, the basolateral membrane conductance. This stimulation appears to be direct and not a secondary response to the elevation of transepithelial transport rate. PMID:1652121

Nagel, W; Katz, U

1991-05-01

64

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

DEFF Research Database (Denmark)

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

Katz, U; Larsen, Erik Hviid

1984-01-01

65

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Hanner, R. H.; Ryan, G. B.

1980-01-01

66

New polymorphic microsatellite markers and development of mitotyping primers for West Mediterranean green toad species (Bufo viridis subgroup).  

Science.gov (United States)

We report new polymorphic microsatellites for three species of Palearctic green toads (Bufo viridis subgroup): 10 in B. balearicus and seven each in B. siculus and B. boulengeri. Diversity at these loci, measured for 27 B. balearicus, 23 B. siculus and 11 B. boulengeri, ranged from low to high (two to 10 alleles). Mitotyping primers, specific to the control region, which allow fast screening of parapatric Sicilian endemic B. siculus and Italian mainland-origin B. balearicus, were developed. PMID:21564854

Colliard, Caroline; Sicilia, Alessandra; Moritz, Craig; Perrin, Nicolas; Stöck, Matthias

2009-07-01

67

Behavioral responses to immune-system activation in an anuran (the cane toad, Bufo marinus): field and laboratory studies.  

Science.gov (United States)

The challenges posed by parasites and pathogens evoke behavioral as well as physiological responses. Such behavioral responses are poorly understood for most ectothermic species, including anuran amphibians. We quantified effects of simulated infection (via injection of bacterial lipopolysaccharide [LPS]) on feeding, activity, and thermoregulation of cane toads Bufo marinus within their invasive range in tropical Australia. LPS injection reduced feeding rates in laboratory trials. For toads in outdoor enclosures, LPS injection reduced activity and shifted body temperature profiles. Although previous research has attributed such thermal shifts to behavioral fever (elevated body temperatures may help fight infection), our laboratory studies suggest instead that LPS-injected toads stopped moving. In a thermal gradient, LPS-injected toads thus stayed close to whichever end of the gradient (hot or cold) they were first introduced; the introduction site (rather than behavioral thermoregulation) thus determined body temperature regimes. Shifts in thermal profiles of LPS-injected toads in outdoor enclosures also were a secondary consequence of inactivity. Thus, the primary behavioral effects of an immune response in cane toads are reduced rates of activity and feeding. Thermoregulatory modifications also occur but only as a secondary consequence of inactivity. PMID:21128787

Llewellyn, D; Brown, G P; Thompson, M B; Shine, R

2011-01-01

68

Toads  

Science.gov (United States)

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

B, Ms.

2011-04-06

69

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

Science.gov (United States)

The extra-cellular matrix of fertilized eggs in the bufonid toads Bufo bufo and Bufotes balearicus was studied to clear the relationships between structural and molecular diversity. Histochemical (PAS, AB pH 2.5 and pH 1.0, Beta-elimination PAS) and lectin-histochemical (Con A, WGA, Succinyl-WGA, PNA, RCA-1, DBA, SBA, AAA, UEA-I, LTA) techniques were used and the observations were made under light and electron microscopy. Both species present a fertilization envelope (FE) and two jelly layers (J1 and J2 ). The fibers of J2 are shared among the eggs of a clutch in a jelly ribbon. The FE of both species presents neutral glycoproteins, mostly N-linked. In B. bufo there are also residuals of mannose and/or glucose and N-acetylglucosamine. In the FE fibers run parallel to egg's surface or are in bundles or looser hanks with no clear orientation. The J1 layer of both species presents sialosulfoglycoproteins, mostly O-linked, with lactosaminylated, galactosaminylated, glycosaminylated, and fucosylated residuals. A lower amount of galactosaminylated residuals is observed in B. balearicus in respect to B. bufo, whereas the opposite is seen in the amount of fucosylated residuals. The J2 layer is similar in composition to J1 but in B. balearicus there are no glucosaminylated residuals. J layers present fibers and granules that reduce towards J2 . Several microorganisms, in particular blue algae, are observed in the J2 layer of both species. In respect to other species, B. bufo and B. balearicus have a lower number of jelly layers, but a comparable number of glycan types. Microsc. Res. Tech. 77:910-917, 2014. © 2014 Wiley Periodicals, Inc. PMID:25091902

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

2014-11-01

70

A light and electron microscopic study of Trypanosoma fallisi N. Sp. in toads (Bufo americanus) from Algonquin Park, Ontario.  

Science.gov (United States)

Trypanosoma fallisi n. sp. is described from Bufo americanus in Ontario. The parasite was observed in 65 of 94 toads examined. The trypanosomes were pleomorphic with respect to the age of infections, being longer and broader in early infections (during spring and summer) and shorter and more slender during late summer and autumn. They ranged in size from 38-76 microns in body length and 3-8 microns in width, with a free flagellum 6-30 microns long. Epizootiological and experimental evidence suggests that this trypanosome is transmitted to the toads by the leech, Batracobdella picta. Trypanosoma fallisi is morphologically similar to T. bufophlebotomi described in Bufo boreas from California, but geographic isolation, host and vector differences as well as slight morphological differences indicate that speciation has occurred. Similar trypanosomes from Bufo americanus (which were identified as T. bufophlebotomi) in Michigan, are probably T. fallisi. This species shares many ultrastructural features with trypanosomes of other lower vertebrates and also of mammals. PMID:2359048

Martin, D S; Desser, S S

1990-01-01

71

Checklist of helminth parasites of the cane toad Bufo marinus (Anura: Bufonidae) from Mexico.  

Science.gov (United States)

Thirty-four adult cane toads Bufo marinus L. (12 males and 22 females) collected from 2 localities in Mexico (Cerro de Oro and Temascal Dams, Oaxaca) in September 2003 were examined for helminth parasites. In total, 14,749 helminths belonging to 14 taxa were collected. Included were 2 adult digeneans (Choledocystus hepaticus, Mesocoelium monas); 1 larval cestode (an unidentified pseudophyllidean); and 11 nematodes, including 3 species of larvae (Contracaecum sp., Physaloptera sp., Physocephalus sexalatus) and 8 species of adults (Aplectana itzocanensis, Cosmocerca sp., Cruzia morleyi, Ochoterenella digiticauda, Oswaldocruzia sp., Raillietnema sp., Rhabdias americanus, and Rhabdiasfuelleborni). Higher species richness was recorded in B. marinus from Cerro de Oro (12 taxa versus 9 in those from Temascal); hosts from both localities shared 7 taxa. There were 25 new locality records, and 2 taxa were registered in Mexico for the first time. To date, 112 helminth species have been recorded parasitizing B. marinus along its native and introduced range of distribution, with 40.5% of them reported from Mexico. PMID:17918380

Espinoza-Jiménez, Arlett; García-Prieto, Luis; Osorio-Sarabia, David; León-Règagnon, Virginia

2007-08-01

72

Sex recognition and mate choice by male western toads, Bufo boreas.  

Science.gov (United States)

In field-based choice experiments, we examined sex recognition and mate choice in male western toads, Bufo boreas. When given a simultaneous choice between a male and a female of equal size, males did not discriminate between the sexes and attempted to amplex a male or a female with equal frequency. When a test male clasped a stimulus male, the stimulus male uttered a release call that caused the test male to release the stimulus male. Male-male amplexus never lasted more than 3 s, but male-female amplexus was tenacious and prolonged. Furthermore, males discriminated between gravid females that differed in body size, choosing larger gravid females over smaller ones, but they did not discriminate between gravid females or non-gravid females of equal size. In choice tests that excluded chemical cues, males jumped more frequently towards large females than small ones. Given that females are significantly larger than males, selecting larger individuals as potential mates increases the probability that males amplex with a female. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour. PMID:9642006

Marco; Kiesecker; Chivers; Blaustein

1998-06-01

73

Urea transport across urinary bladder and salt acclimation in toad (Bufo viridis).  

Science.gov (United States)

The fluxes of urea across the urinary bladder of the toad Bufo viridis have been studied under conditions of acclimation to tap water or 500 mosM NaCl solution. The [14C]urea fluxes were measured simultaneously with [3H]inulin to test for nonspecific leakage. The fluxes are quite high (Ktrans = 75 x 10(-7) cm/s at 5 mmol/l urea) and are similar in either the mucosal-to-serosal or the opposite direction. "Summer" rates were five to six times higher than the "winter" rates. Antidiuretic hormone (ADH), theophylline, and forskolin increased the fluxes to variable degrees (two to five times), similar in the two acclimation conditions. Phloretin inhibited the urea fluxes by nearly 50%. 1,3-Dimethylurea and thiourea, but not acetamide, competed with the urea fluxes effectively. The fluxes of urea were not affected by the osmotic water flow, although both responded to ADH. It is concluded that urea transport across the urinary bladder of B. viridis is by facilitated diffusion through a specific pathway independent of water flux. The inhibitory effect of the structural analogues on the urea flux was affected by salt acclimation, whereas most other characteristics did not differ significantly at 5 mmol/l external urea under the two conditions of acclimation. PMID:2331031

Shpun, S; Katz, U

1990-04-01

74

A new type of cell in the larval epidermis of the green toad, Bufo viridis viridis.  

Science.gov (United States)

The flank skin of the premetamorphic stage of the green toad, Bufo viridis viridis, was studied by transmission electron microscopy. The skin was typically larval amphibian, made up of a highly fibrous and vascular dermis to the inside and a highly cellular epidermis to the outside with a distinct basal lamina separating the two layers. The epidermis is three-cells thick. The epidermal cells, mostly keratinocytes, are closely packed together and are attached to each other through desmosomes and interdigitations. The basal keratinocytes are anchored to the basal lamina through hemidesmosomes. In addition to the keratinocytes, some other types of cells known in the amphibian larval skin were found. These cells include mucus-secreting, mitochondria-rich cells, Merkle cells and flask cells. Anew type of cells, the dark cells, are described in this paper. The dark cell rests on the basal lamina. It is a ramified cell with a number of cytoplasmic processes intervening in between the keratinocytes. The cytoplasm is strikingly dark and rich with polysomes and granular endoplasmic reticulum. PMID:19058540

Al-Adhami, Mohammad Amin; Qar, Janti S

2005-01-01

75

Natural and experimental infection of the lizard Ameiva ameiva with Hemolivia stellata (Adeleina: Haemogregarinidae) of the toad Bufo marinus.  

Science.gov (United States)

Developmental stages of a haemogregarine in erythrocytes of the lizard Ameiva ameiva (Teiidae), from Pará State, north Brazil, were shown to be those of Hemolivia by the nature of the parasite's sporogonic cycle in the tick Amblyomma rotondatum. The type species, Hemolivia stellata Petit et al., 1990 was described in the giant toad Bufo marinus and the tick Amblyomma rotondatum, also from Pará State, and in view of the fact that A. ameiva and Bufo marinus share the same habitat and are both commonly infested by A. rotondatum, the possibility that the parasite of A. ameiva is H. stellata had to be considered. Uninfected lizards fed with material from infected ticks taken from B. marinus, and others fed with liver of toads containing tissue-cysts of H. stellata, were shown to subsequently develop typical Hemolivia infections, with all stages of the development similar to those seen in the naturally infected lizards. Conversely, a juvenile, uninfected toad became infected when fed with sporocysts of Hemolivia in a macerated tick that had fed on an infected A. ameiva and pieces of liver containing tissuecysts from the same lizard. The remarkable lack of host specificity shown by H. stellata, in hosts so widely separated as an amphibian and a reptile, is discussed. PMID:18225421

Lainson, R; De Souza, M C; Franco, C M

2007-12-01

76

Renal response of euryhaline toad (Bufo viridis) to acute immersion in tap water, NaCl, or urea solutions.  

Science.gov (United States)

Green toads (Bufo viridis) were acclimated to either tap water, 230 mOsmol NaCl kg-1 H2O (saline), 500 mOsmol NaCl kg-1 H2O (high saline), or 500 mmol L-1 urea. Renal functions for each acclimation group were studied on conscious animals that had one ureter chronically catheterized. Reciprocal immersion of tap-water- and saline-acclimated toads in the opposite solution did not stress the animals osmotically, and plasma osmolality increased or decreased by no more than 15%. However, urine osmolality and ionic composition changed immediately and profoundly on exposure to the other solution. Exposure of tap-water-acclimated toads to saline decreased urine flow by 30%, whereas the reciprocal immersion led to an increase of 30%. Immersion of tap-water-acclimated toads in high saline led to immediate cessation of urine flow, whereas immersion of 500 NaCl- or urea-acclimated toads in tap water led to a large increase in urine flow, with an overshoot that lasted 10 h (as a result of either salt or urea diuresis). Urine flow then stabilized at a level 5-6 times higher than the value attained at high-salt environment. On immersion of 500 urea-acclimated toads in 500 NaCl, urine flow doubled, accompanied by a change in ion composition, without change in the osmolality. In all experimental conditions, plasma potassium concentration was maintained within a narrow range. The results show that the toad's kidneys contributed efficiently both to osmo- and ionoregulation in a wide range of ambient solutions. PMID:10068626

Shpun, S; Katz, U

1999-01-01

77

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

Science.gov (United States)

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.

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

2010-01-01

78

Effects of Multiple Routes of Cadmium Exposure on the Hibernation Success of the American Toad (Bufo americanus)  

Science.gov (United States)

The effects of multiple routes of cadmium exposure on juvenile American toads (Bufo americanus) were evaluated using environmentally relevant concentrations. During or after exposure, toads were individually hibernated for 172 days at approximately 4??C. The following experiments were conducted: (1) dermal exposure (hibernation in soil contaminated with up to 120 ??g Cd/ g (dry weight)); (2) injection exposure (single injection with cadmium to achieve a maximum whole-body nominal concentration of 3 ??g Cd/g (wet weight) 12 days before hibernation in uncontaminated soil); and, (3) oral exposure (feeding with mealworms containing ???16 ??g Cd/g (dry weight) for 50 days before hibernation in uncontaminated soil)., We hypothesized that sublethal levels of cadmium would become lethal during hibernation because of combined chemical and cold stress. No prehibernation mortality occurred in the injection and oral exposure studies. There was a significant treatment effect on whole-body cadmium concentration in toads orally or dermally exposed and on percent of cadmium retention in toads orally exposed. There was also a trend of increased time-to-burrowing and more toads partially buried with greater cadmium concentration in the dermal study, which indicated avoidance. In all 3 experiments, no significant differences were found among cadmium treatments in hibernation survival, percent of mass loss, or locomotor performance. However, toads fed mealworms averaging 4.7 ??g Cd/g (dry weight) had only 56% survival compared with 100% survival for controls. Although our results suggest that environmentally relevant levels of cadmium do not pose a great risk to American toads, factors such as soil type or prey species may increase cadmium bioavailability, and other amphibian species may be more sensitive to cadmium than B. americanus.

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

2004-01-01

79

Identification and characterization of gastrointestinal hormone immunoreactive cells in the skin and parotoids of Chinese toad Bufo gargarizans.  

Science.gov (United States)

The skin and skin secretion of Chinese toad Bufo gargarizans have long been used in traditional Chinese medicine. However, the exact types and location of bioactive substances in Bufo gargarizans skin still have not been fully elucidated. The aim of the study was to investigate the distribution and density of six types of gastrointestinal (GI) hormone immunoreactive (IR) cells in the skin and parotoids of Bufo gargarizans. Immunohistochemistry was used for qualitative and semiquantitative analysis of GI hormone presence in the dorsal and ventral skin, and parotoids of eight adult Chinese toads. Six types of IR cells were found: serotonin (5-HT), glucagon (GLU), gastrin (GAS), somatostatin (SS), pancreatic polypeptide (PP) and neuropeptide Y(NPY) IR cells. They were mainly present in the epidermis and skin glands. 5-HT-IR cells were distributed in all layers of epidermis and glands, with higher density in the glands. Glucagon was prominently expressed in the epidermis and the bottle-shaped glands of parotoids; however, it was not present in the granular glands of skin and parotoids. The distributions of GAS and SS-IR cells were similar since they were present mainly in mucous, granular and bottle-shaped glands, while these cell types were absent in the differentiated glands of parotoids. PP-IR cells were predominant in the granular glands and the bottle-shaped glands. The expression of NPY was high in epidermal stratum granulosum and mucous glands of the dorsal skin, the bottle-shaped glands and differentiated glands of parotoids, while NPY-IR was rarely seen in the granular glands of ventral skin, and not present in the granular glands of dorsal skin and parotoids. The expression of several types of GI hormones in the skin and parotoids of Bufo gargarizans varies depending on tissue and type of glands. PMID:25007183

Wang, Huan; Wu, Yuan-Yuan; Zhang, Rui; Zhu, Xue; Zhang, Sheng-Zhou

2014-01-01

80

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

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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

HRVOJ OSTOJIC

2000-01-01

 
 
 
 
81

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english 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

HRVOJ, OSTOJIC; CARLOS, MONGE-C; VERONICA, CIFUENTES.

82

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

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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.

Seratt Jessica

2006-06-01

83

Prevalence of Salmonella spp. in cane toads (Bufo marinus) from Grenada, West Indies, and their antimicrobial susceptibility.  

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Cloacal swabs and caecal contents sampled from 58 cane toads (Bufo marinus) in St George's parish, Grenada, during a 7-month period in 2011 were examined by an enrichment and selective culture method for presence of Salmonella spp. Twenty-four (41%) toads were positive for Salmonella spp. of which eight were Salmonella enterica serovar Javiana, and eight were S. enterica serovar Rubislaw. The other serovars were as follows: Montevideo, 6; Arechavaleta, 1; and serovar: IV:43:-:-, 1. The high frequency of isolation of serovar Javiana, an emerging human pathogen associated with several outbreaks in the recent years in the eastern United States, suggests a possible role for cane toads in transmission of this serovar. Although S. Rubislaw has been isolated from lizards, bats and cases of some human infections, there is no report of its carriage by cane toads, and in such high frequency. The rate of carriage of S. Montevideo, a cause for human foodborne outbreaks around the world was also over 10% in the 58 toads sampled in this study. The antimicrobial drug susceptibility tests against amoxicillin-clavulanic acid, ampicillin, cefotaxime, ceftazidime, ciprofloxacin, enrofloxacin, gentamicin, imipenem, nalidixic acid, streptomycin, tetracycline and trimethoprim-sulfamethoxazole showed that drug resistance is minimal and is of little concern. Antimicrobial resistance was limited to ampicillin and amoxicillin-clavulanic acid in one isolate of S. Javiana and one isolate of S. Rubislaw. This is the first report of isolation and antimicrobial susceptibilities of various Salmonella serovars not identified previously in cane toads in Grenada, West Indies. PMID:23035820

Drake, M; Amadi, V; Zieger, U; Johnson, R; Hariharan, H

2013-09-01

84

Wildfire effects on water temperature and selection of breeding sites by the Boreal Toad (Bufo boreas) in seasonal wetlands  

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Disturbances can significantly affect the thermal regime and community structure of wetlands. We investigated the effect of a wildfire on water temperature of seasonal, montane wetlands after documenting the colonization of recently burned wetlands by the Boreal Toad (Bufo boreas boreas). We compared the daily mean temperature, daily maximum temperature, and accumulated growing degree days measured on the north shore of three classes of wetlands: unburned wetlands, burned wetlands that were colonized by breeding toads, and burned wetlands that were not colonized. We hypothesized that toads colonized burned wetlands because they were warmer than unburned wetlands and selected specific burned wetlands because they were warmer than neighboring burned sites. There was weak evidence that toads selected burned wetlands with higher temperature maxima; however, the differences were small (???1??C) and were not supported when accounting for geography and wetland features. We also found no evidence that burning the forest around wetlands increased water temperatures two and three years after the fire. Unburned wetlands had higher daily mean and maximum temperatures and accrued more growing degree days than either class of burned wetlands. Temperature differences among groups of wetlands seemed to be driven by subtle differences in geography. We suspect we did not find warmer temperatures in burned wetlands because all of the wetlands we monitored already had open canopies and the fire likely resulted in only small increases in incident radiation. Copyright ?? 2008. Blake R. Hossack. All rights reserved.

Hossack, B.R.; Corn, P.S.

2008-01-01

85

Nonparallel secretion of pepsinogen and acid by gastric oxyntopeptic cells of the toad (Bufo marinus).  

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Pepsinogen and HCl secretion in the amphibian stomach are performed by a single cell type, the oxyntopeptic cell. These functions were studied in gastric mucosae of toads (Bufo marinus) mounted in Ussing-type chambers. HCl and peptic activity of luminal fluid were measured by titration and proteolysis of albumin, respectively. Distribution of pepsinogen in the gastric mucosa was heterogeneous, activity being highest in the proximal part of the stomach. Zymogen granules in the oxyntopeptic cell were more abundant in the deeper cells of the glands and in the fundus. On stimulation, the granules were released into the lumen of the glands by exocytosis. Histamine, forskolin, or carbachol alone each induced an increase in HCl and pepsinogen secretion. Carbachol after maximal histamine or forskolin stimulation produced an extra increase in both secretions that was greater for pepsinogen response. Similarly, joint addition of carbachol and histamine was more potent than histamine alone for both parameters; however, the effect was greater on pepsinogen release. Pretreatment with cimetidine blocked HCl and pepsinogen responses to carbachol but did not affect responses to forskolin. Addition of omeprazole to forskolin-stimulated mucosae uncoupled the two secretions, inducing a total inhibition of HCl secretion with a slight reduction in pepsinogen secretion. Thus pepsinogen release, similar to HCl secretion, is sensitive to cAMP and Ca(2+)-dependent secretagogues. However, the action of Ca2+ would require the previous elevation of cAMP induced by the different secretagogues. In such a case, the increase in intracellular Ca2+ would result in a nonparallel activation of the two secretions. PMID:8238523

Ruiz, M C; Acosta, A; Abad, M J; Michelangeli, F

1993-11-01

86

Digitalis-like compounds in the toad Bufo viridis: tissue and plasma levels and significance in osmotic stress.  

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Digitalis-like compounds (DLC), constituents of animal tissues, are possible regulators of the Na+, K(+)-ATPase implicated in water and salt homeostasis. The distribution of DLC in the toad (Bufo viridis) was determined following methanol extraction and partial purification. DLC highest levels were found in the skin but it was also detected in the plasma and many internal organs. Short term (hours) exposure of the toad to hypertonic shock (1.5% NaCl) induced an increase in plasma osmolarity due to an increase in Na+ and Cl- levels. This treatment induced a transient, three fold, increase of DLC levels in the brain and transient reduction of its levels in the ventral skin. Acclimation of the toads to burrowing conditions for six weeks resulted in an increase in plasma osmolarity due to a large increase in plasma urea with a small increase in ion concentrations. Under these conditions DLC levels in the dorsal skin increased by 100% without alteration of its levels in the plasma, brain and ventral skin. DLC levels in the toad brain of control animals, showed a significant dependence on season, being highest in the summer and lowest in the winter. DLC levels in the skin peaked in May while the levels in the plasma were season independent. The changes in DLC levels induced by the short- as well as long-term perturbations in the animal environmental salinity together with the seasonal differences suggest that DLC in the toad is involved in water and salt homeostasis of these animals, but may also participate in other unknown functions. PMID:1614277

Lichtstein, D; Gati, I; Haver, E; Katz, U

1992-01-01

87

Salt and water balance in the toad Bufo viridis during recovery from two different osmotically stressful conditions.  

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Toads, Bufo viridis, were subjected to two modes of osmotic stress: on soil of water potential approximately 5 atm and continuous partial immersion in 250 mmol/l NaCl solution. In both conditions, plasma osmolality was greatly elevated involving a large increase in urea concentration and was maintained hyperosmotic to the external environment. After acclimation to either condition, toads were allowed access to tap water, and the concentrations of body fluids and gross body weight were followed over a 7-day period. The toads bathed only until preacclimation gross weight was regained, although plasma osmolality remained elevated. Weight remained stable thereafter. Excess plasma Na+ and Cl- were eliminated within a few days, whereas the urea level diminished very slowly. K+ was closely controlled throughout, both during acclimation and recovery. The results suggest that B. viridis is equipped with a series of set points for osmotic pressure that enable it to maintain different steady states according to the prevailing conditions, the magnitude of the shift depending on the level of the imposed osmotic stress. PMID:9185343

Hoffman, J; Katz, U

1997-05-01

88

The effect of sex hormones on lipid content and mast cell number in the harderian gland of the female toad, Bufo viridis.  

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The Harderian gland of the toad Bufo viridis is a dimorphic gland owing to the presence of lipid droplets in the female glandular cells present only during summer months. Ovariectomy causes the disappearance of sudanophilia and estrogen-treatment completely prevents this change, while testosterone-injection has little effect. Estradiol-treatment also provokes a proliferation of the interstitial connective tissue concomitantly with the mast cell number increase. Our results suggest that estradiol acts, stimulating both mast cell and connective tissue proliferation, and plays a role in determining the expression of the female type of the toad Harderian gland. PMID:7886670

Minucci, S; Chieffi Baccari, G; Di Matteo, L

1994-12-01

89

Infection dynamics of the lungworm Rhabdias pseudosphaerocephala in its natural host, the cane toad (Bufo marinus), and in novel hosts (native Australian frogs).  

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Host-parasite systems have often evolved over time, such that infection dynamics may become greatly modified from the time of initial contact of the host with the parasite. Biological invasions may be useful to clarify processes in the initial contact of hosts with parasites, and allow us to compare parasite uptake between the ancestral (coevolved) host and novel (noncoevolved) hosts. Cane toads (Bufo marinus) are spreading rapidly through tropical Australia, carrying with them a nematode lungworm (Rhabdias pseudosphaerocephala) congeneric with those found in Australian frogs. We investigated the dynamics of infections of the toad parasite by conducting histologic examinations of cane toads and three native Australian frogs (Litoria dahlii, Litoria nasuta, and Opisthodon ornatus) at 2, 6, and 10 days after experimental exposure to the toad lungworm. More worms were found in toads than in frogs, especially at longer periods postexposure. In toads, the infective larvae entered the skin and muscles within 2 days postexposure, passed into the coelom in 6 days, and reached the lungs at 10 days. In frogs, larvae were found in many organs rather than migrating to consistent target tissues; a few larvae reached the lungs of L. dahlii. Migratory larvae caused increasing inflammation (primarily granulomatous admixed with granulocytes then lymphocytes) through time, especially in frogs. Evolution has resulted in an enhanced ability of the lungworm to locate the target organ (the lungs) of the toad, and an increase in rates of parasite survival within this host. PMID:20966266

Pizzatto, Ligia; Shilton, Catherine M; Shine, Richard

2010-10-01

90

Anticancer Peptide fromChinese Toad (Bufo Bufo Gargarizans Skin Enhanced Sensitivity to 5-Fu in Hepatocarcinoma cells (HepG2  

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Full Text Available OBJECTIVE To investigate the antiproliferative and apoptogenic activities of peptide extracted from the Chinese toad (Bufo bufogargarizans skin (TSP and its effects on hepatocarcinoma cell line.METHODS MTT assaywas used to detect the effects of TSP (50 mg/mL and 5 mg/mL on the proliferation and viability of Hepatocarcinoma cell line (HepG2 and liver cell line (L-02; Flow cytometry was used in DNA content analysis to determine the cell distribution in different phases of cell cycle; Annexin V-FITC/PI stained fluorescence-activated cell sorter (FACS and transmission electron microscope (TEM were used to detect the apoptosis of the treated cells.RESULTS TSP could not suppress the proliferation and viability of normal liver L-02 cells, but strongly inhibited the proliferation and viability of HepG2 cells; TSP (50 mg/mL primarily arrested the HepG2 cells at G1 phase of the cell cycle; TSP (50 mg/mL induced apoptosis in HepG2 cells and enhanced the effects of 5-Fu.CONCLUSION TSP has potent antineoplastic activity against human hepatocarcinoma cells with little toxicity to normal liver cells and can enhance the effects of 5-Fu.

Chuang-xin LU

2011-09-01

91

Enhancement of angiogenesis in regenerating gastrocnemius muscle of the toad (Bufo viridis) by low-energy laser irradiation.  

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The effect of low-energy laser (He-Ne) irradiation on the process of neoformation of blood capillaries during regeneration in the toad (Bufo viridis) gastrocnemius muscle was studied using histomorphometric methods. The injured zones of the experimental toads were subjected to four direct He-Ne laser irradiations (632.8 nm wavelength; 6.0 mW for 2.3 min) every alternate day, commencing on the second day after injury. Muscles that were injured as above and subjected to red light irradiation served as control. The volume density (cm3/cm3) of the capillaries in the injured zone at 9 days after injury was significantly (P < 0.01) higher (0.09 +/- 0.006) than in the control muscles (0.048 +/- 0.007). At 14 days after injury, the volume density in the injured zone of the control muscles further increased, while the value in the laser-irradiated muscles remained unchanged. The surface density (m2/cm3) of the capillaries in the injured zone was 2.3-fold higher in the laser-irradiated muscles than in the control muscles at 9 days after injury. The surface density further increased in the control muscles between 9 and 14 days after injury, while in the laser-irradiated muscles there was a decrease in this value during the above period. The surface-to-volume ratios of the capillaries in the injured zone of control and laser-irradiated muscles indicate a straighter, rather than a convoluted appearance between 9 and 14 days after injury. It is concluded that He-Ne laser irradiation during skeletal muscle regeneration in the toad markedly promotes the process of neoformation of blood vessels in the injured zone.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7534455

Bibikova, A; Belkin, V; Oron, U

1994-12-01

92

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.  

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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

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

2014-01-01

93

[Variation of microsatellites BM224 and Bcal7 in populations of green toads (Bufo viridis complex) with various nuclear DNA content and ploidy].  

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We studied variation of microsatellites BM224 and Bcal7 in three species of the Bufo viridis diploid-polyploid complex. We found that locus Bcal7 in all examined samples was monomorphic. Three alleles of microsatellite BM224 were found. Among tetraploid toads, the western species B. oblongus had only one allele variant, whereas the eastern species B. pewzowi had two other alleles. Similar distribution of alleles was observed in triploid specimens, collected in the area borders of tetraploid and diploid species. Among samples of diploid toad B. viridis, we found all three allele variants of microsatellite BM224. Their distribution was geographically determined. A comparison of allele distribution with genome size variation in diploid toads showed very similar patterns. PMID:16841495

Litvinchuk, S N; Rozanov, Iu M; Usmanova, N M; Borkin, L Ia; Mazanaeva, L F; Kazakov, V I

2006-01-01

94

Promotion of muscle regeneration in the toad (Bufo viridis) gastrocnemius muscle by low-energy laser irradiation.  

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The effect of low-energy laser (He-Ne) irradiation on the process of skeletal muscle regeneration after cold injury to the gastrocnemius muscle of the toad (Bufo viridis) was studied using quantitative histological and morphometric methods. The injured zones in the experimental toads were subjected to five direct He-Ne laser (632.8 nm wavelength) irradiations (6.0 mW for 2.3 min) every alternate day starting on the fourth day postinjury. Muscles that were injured as above, and subjected to red-light irradiation, served as a control group. Morphometric analysis was performed on histological sections of injured areas at 9, 14, and 30 days postinjury. At 9 days postinjury, mononucleated cells populated 69.3% +/- 16.8% of the total area of injury. Thereafter, their volume fraction (percent of total injured zone) decreased gradually but more rapidly in the laser-irradiated muscle than in the control. The volume fraction of the myotubes in the laser-irradiated muscles at 9 days of muscle regeneration was significantly higher (7.0% +/- 2.2%) than in the control muscle (1.2% +/- 0.4%). Young myofibers in the laser-irradiated muscles populated 15.5% +/- 7.9% and 65.0% +/- 9.5% of the injured area at 9 and 14 days of muscle regeneration, respectively, while in control muscles these structures were not evident at 9 days and made up only 5.3% +/- 2.9% of the traumatized area at 14 days postinjury. The volume fraction of the young myofibers further increased by 30 days of muscle regeneration making up 75.7% +/- 13.2% of the traumatized area, while in the laser-irradiated muscles most of the injured zone was filled with mature muscle fibers.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8430907

Bibikova, A; Oron, U

1993-03-01

95

Effects of meal size, meal type, body temperature, and body size on the specific dynamic action of the marine toad, Bufo marinus.  

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Specific dynamic action (SDA), the accumulated energy expended on all physiological processes associated with meal digestion, is strongly influenced by features of both the meal and the organism. We assessed the effects of meal size, meal type, body temperature, and body size on the postprandial metabolic response and calculated SDA of the marine toad, Bufo marinus. Peak postprandial rates of O(2) consumption (.V(O2)) and CO(2) production (.V(CO2)) and SDA increased with meal size (5%-20% of body mass). Postprandial metabolism was impacted by meal type; the digestion of hard-bodied superworms (Zophobas larva) and crickets was more costly than the digestion of soft-bodied earthworms and juvenile rats. An increase in body temperature (from 20 degrees to 35 degrees C) altered the postprandial metabolic profile, decreasing its duration and increasing its magnitude, but did not effect SDA, with the cost of meal digestion remaining constant across body temperatures. Allometric mass exponents were 0.69 for standard metabolic rate, 0.85 for peak postprandial .V(O2), and 1.02 for SDA; therefore, the factorial scope of peak postprandial .V(O2) increased with body mass. The mass of nutritive organs (stomach, liver, intestines, and kidneys) accounted for 38% and 20% of the variation in peak postprandial .V(O2) and SDA, respectively. Toads forced to exercise experienced 25-fold increases in .V(O2) much greater than the 5.5-fold increase experience during digestion. Controlling for meal size, meal type, and body temperature, the specific dynamic responses of B. marinus are similar to those of the congeneric Bufo alvarius, Bufo boreas, Bufo terrestris, and Bufo woodhouseii. PMID:12601612

Secor, Stephen M; Faulkner, Angela C

2002-01-01

96

Breeding habit of the toad Bufo coccifer in Costa Rica, with a description of the tadpole  

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The breeding habits of Bufo coccifer were studied in northwestern Costa Rica between 1971 and 1974. This species breeds during the rainy season, at least from May through August. Males chorus from areas of shallow water. Their calls resemble those of Mexican representatives of the species in pulse rate and duration, but are closer to those of other Costa Rican and Panamanian populations in dominant frequency. Thus, our data do not clearly support recognition of Bufo cycladen as a distinct species for the Mexican populations. Amplexus is axillary, and two strings of eggs are extruded simultaneously during oviposition. Tadpoles, described for the first time in this paper, are secretive and do not aggregate. Development to metamorphosis requires about 5 weeks.

McDiarmid, R.W.; Foster, M.S.

1981-01-01

97

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

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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.

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

2005-12-01

98

Histochemical investigations on the secretory cells in the oesophagogastric tract of the Eurasian green toad, Bufo viridis.  

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The secretory cells of the oesophagogastric tract of the Eurasian toad, Bufo viridis, were examined using standard histochemical methods and lectin histochemistry. Two goblet cell types were found in the oesophageal epithelium, differing in their morphology and the histochemical features of the secretory granules. These contained mainly acidic glycoconjugates, both sulphated and carboxylated, and a small amount of pepsinogen. Type I goblet cells contained stable class-III mucosubstances, which were absent in Type II. No pluricellular oesophageal glands were found. The oesophagogastric junction had a superficial epithelium similar to that of the oesophageal epithelium, with alveolar pluricellular glands, secreting stable class-III mucins, and few oxynticopeptic cells. The gastric mucosa presented secretory cells both in the surface epithelium and in the gastric glands. Superficial and foveolar cells produced neutral mucins with Gal(beta)1,3GalNAc residues. Neck cells, oxynticopeptic cells and endocrine cells were found in the gastric glands. Neck cells produced stable class-III mucosubstances. A functional gradient was observed in the oxynticopeptic cells from the oral to the aboral fundus, with a decrease in pepsinogen secretion towards the aboral fundus and a possible increase in HCl secretion. In the pyloric mucosa, the oxynticopeptic cells disappeared and the glands produced only neutral mucins, without stable class-III mucosubstances. PMID:12945734

Liquori, Giuseppa E; Scillitani, Giovanni; Mastrodonato, Maria; Ferri, Domenico

2002-10-01

99

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

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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.

Mesut Sahin

2006-01-01

100

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

International Nuclear Information System (INIS)

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)

 
 
 
 
101

[Serotonin inhibits phorbol ester-induced oocyte maturation in the green toad (Bufo viridis)].  

Science.gov (United States)

The activator of protein kinase C phorbol-12-myristat-13-acetate (PMA) induces maturation of the definitive intact (coated with the follicular envelopes) and defolliculated oocytes of the green toad. This effect is more pronounced in case of defolliculated oocytes. The amount of matured oocytes depends on the PMA concentration in solution. Serotonin (5-HT) inhibits or blocks maturation of the oocytes induced either by progesterone or by PMA. A possible mechanism of this effect is discussed with special reference to its role in regulation of oocyte maturation. PMID:8725438

Nikitina, L A; Buznikov, G A

1996-01-01

102

Renal function at steady state in a toad (Bufo viridis) acclimated in hyperosmotic NaCl and urea solutions.  

Science.gov (United States)

Kidney function of the euryhaline toad Bufo viridis was studied in animals acclimated to tap water and solutions of NaCl (230 and 500 mosmol.kg-1 H2O) and urea (500 mmol.l-1) in steady-state conditions. An ureter was catheterized for continuous urine collection and blood was sampled from an iliac artery. A single injection of 3H-inulin served for estimation of glomerular filtration rate: this was in the range of 15-27 ml.kg-1.h-1 and did not differ significantly in any of the acclimation conditions. Urine flow, on the other hand, varied considerably and was highest in tap water (18.2 +/- 3.2 ml.kg-1.h-1; urine/plasma inulin ratio = 0.88), lower in 230 mosmol.kg-1 H2O NaCl solution (13.5 +/- 3.9 ml.kg-1.h-1; u/p inulin ratio = 1.73) and lowest in 500 mosmol.kg-1 H2O NaCl or urea acclimation solutions (5-7 ml.kg-1.h-1; u/p inulin = 3.7-4.2). Clearance of free water was high in the tap water group, lower in 230 mosmol.kg-1 H2O NaCl solution, and much lower in the hyperosmotic acclimation conditions. Clearances of both Na+ and Cl- were similar under our experimental conditions, but changed independently in accordance to the composition of the acclimation solution. Potassium clearance was similar in all acclimation conditions, and a constant plasma K+ concentration was maintained. Urea clearance was high in tap water and 500 mmol.l-1 urea acclimation groups and low in the NaCl acclimations.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7738233

Shpun, S; Katz, U

1995-01-01

103

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

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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.

Petar Boyadzhiev

2009-07-01

104

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

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

105

Effect of bromocriptine on the larval skin of the green toad, Bufo viridis viridis leurenti.  

Science.gov (United States)

In the premetamorphic larval green toad, B. viridis viridis, as in other anurans, the skin is made up of a fibrous dermis and an epidermis of stratified epithelium. The effects of bromocriptine, an antiprolactin drug, on the premetamorphic skin of B. viridis viridis was examined. Bromocriptine, dissolved in rearing water at four different concentrations, induced a number of changes in the skin of treated tadpoles. In rough sequence of appearance, these changes include: retraction ofthe melanocyte dendrites, synchronous burst ofthe apical vesicles of the superficial epithelial cells, gradual disappearance of the melanosomes from the epithelial cells and widening of the intercellular spaces. In addition, macrophages appeared in the superficial dermis amongst the retracted melanocytes. White crystals were observed on the skin surface and similar crystals were ingested by the macrophages. Prolonged treatment with bromocriptine resulted in hypertrophy and extraction of some epidermal cells. Deep melanocytes of the mesenteries were not affected by bromocriptine-treatment indicating that the drug did not penetrate deep into the tadpole tissue. Whether the macrophages observed in the dermis were recruited from deeper tissues or were converted melanocytes is another issue in need of study. PMID:17687933

Al-Adhami, Mohammad A; Qar, Janti

2007-01-01

106

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

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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

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

2004-08-01

107

What's the Difference between Frogs and Toads?  

Science.gov (United States)

The difference between frogs and toads can be determined scientifically but is based in the historic use of the terms frog and toad. These are Old English words for the common frog, "Rana temporaria," and the common toad, "Bufo bufo," both inhabitants of the British Isles. In the process of describing a new anuran species, scientists refer to it…

Brown, Herrick

2004-01-01

108

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

Wen, Chen; Liu-wang, Nie; Ping-ping, Zheng.

109

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

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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.

Wen Chen

2007-01-01

110

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

International Nuclear Information System (INIS)

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

111

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

Energy Technology Data Exchange (ETDEWEB)

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 {mu}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.

James, Stacy M. [Division of Biological Sciences, 105 Tucker Hall, University of Missouri-Columbia, Columbia, MO 65211-7400 (United States)]. E-mail: smj21b@mizzou.edu; Little, Edward E. [U.S. Geological Survey Columbia Environmental Research Center, 4200 New Haven Road, Columbia, MO 65201-8709 (United States); Semlitsch, Raymond D. [Division of Biological Sciences, 105 Tucker Hall, University of Missouri-Columbia, Columbia, MO 65211-7400 (United States)

2004-12-01

112

A vertebrate reproductive system involving three ploidy levels: hybrid origin of triploids in a contact zone of diploid and tetraploid palearctic green toads (Bufo viridis subgroup).  

Science.gov (United States)

The rise and consequences of polyploidy in vertebrates, whose origin was associated with genome duplications, may be best studied in natural diploid and polyploid populations. In a diploid/tetraploid (2n/4n) geographic contact zone of Palearctic green toads in northern Kyrgyzstan, we examine 4ns and triploids (3n) of unknown genetic composition and origins. Using mitochondrial and nuclear sequence, and nuclear microsatellite markers in 84 individuals, we show that 4n (Bufo pewzowi) are allopolyploids, with a geographically proximate 2n species (B. turanensis) being their maternal ancestor and their paternal ancestor as yet unidentified. Local 3n forms arise through hybridization. Adult 3n mature males (B. turanensis mtDNA) have 2n mothers and 4n fathers, but seem distinguishable by nuclear profiles from partly aneuploid 3n tadpoles (with B. pewzowi mtDNA). These observations suggest multiple pathways to the formation of triploids in the contact zone, involving both reciprocal origins. To explain the phenomena in the system, we favor a hypothesis where 3n males (with B. turanensis mtDNA) backcross with 4n and 2n females. Together with previous studies of a separately evolved, sexually reproducing 3n lineage, these observations reveal complex reproductive interactions among toads of different ploidy levels and multiple pathways to the evolution of polyploid lineages. PMID:19863582

Stöck, Matthias; Ustinova, Jana; Lamatsch, Dunja K; Schartl, Manfred; Perrin, Nicolas; Moritz, Craig

2010-04-01

113

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

Science.gov (United States)

One-hundred twelve amphibians, including 51 blue-spotted salamanders, Ambystoma laterale, 30 eastern American toads, Bufo americanus americanus, and 31 northern leopard frogs, Rana pipiens, were collected during April-October 1996 from Waukesha County, Wisconsin and examined for helminth parasites. The helminth compound community of this amphibian assemblage consisted of at least 10 species: 9 in American toads, 8 in leopard frogs, and 3 in blue-spotted salamanders. American toads shared 7 species with leopard frogs, and 2 species occurred in all 3 host species. Although there was a high degree of helminth species overlap among these sympatric amphibians, statistically significant differences were found among host species and percent of indirect or direct-life cycle parasites of amphibian species individual component communities (chi2 = 1,015, P toads had a higher relative abundance of nematodes, 59%, than larval cestodes, 31%, and larval and adult trematodes, 10%, whereas leopard frogs had a higher relative abundance of larval cestodes, 71.3%, and larval and adult trematodes, 25.3%, than nematodes 3.4%. This is related to ecological differences in habitat and dietary preferences between these 2 anuran species. Helminth communities of blue-spotted salamanders were depauperate and were dominated by larval trematodes, 94%, and few nematodes, 6%. Low helminth species richness in this host species is related to this salamander's relatively small host body size, smaller gape size, lower vagility, and more fossorial habitat preference than the other 2 anuran species. Adult leopard frogs and toads had significantly higher mean helminth species richness than metamorphs, but there was no significant difference in mean helminth species richness among adult and metamorph blue-spotted salamanders. Considering adult helminths, the low species richness and low vagility of caudatans as compared with anurans suggest that local factors may be more important in structuring caudatan helminth communities of salamanders than of anuran hosts. Helminth species infecting salamanders may be more clumped in their geographic distribution as compared with anurans, and the role of other hosts and their parasites at the compound community level may be important in structuring helminth communities of salamanders. PMID:14533672

Bolek, Matthew G; Coggins, James R

2003-08-01

114

Quantitative structure-activity analyses of bufokinin and other tachykinins at bufokinin (bNK1) receptors of the small intestine of the cane toad, Bufo marinus.  

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The toad tachykinin, bufokinin (Lys-Pro-Arg-Pro-Asp-Gln-Phe-Tyr-Gly-Leu-Met amide; BUF), acts via tachykinin NK1-like receptors to contract the intestine of the cane toad, Bufo marinus. In this structure-activity study, we used isolated segments of toad small intestine and performed binding studies with [125I] Bolton-Hunter BUF in intestinal membranes to compare the contribution of individual amino acid residues to the potencies of 18 naturally occurring tachykinins and 13 BUF analogs. Potencies were similar (r=0.94) in functional and binding studies, with BUF and ranakinin being most potent. Ranatachykinin A, physalaemin, hylambatin and cod, trout and mammalian SPs exhibited 10-60% of the potency of BUF. The Ala-substituted BUF analogs were 11-60% as potent as BUF in functional studies, with [Ala2]-BUF and [Ala4]-BUF the least efficacious, indicating the importance of both proline residues. QSAR equations were developed using 12 connectivity, shape and steric parameters for each of the 7 hypervariable amino acid residues in these peptides. For the binding data, the optimal regression equation explained 81% of the variance, and indicated the importance of the steric function at [Pro2] and simple connectivity functions at [Gln6] and [Tyr8]. The optimal functional regression equation (80% of variance) confirmed the importance of connectivity functions at [Gln6] and [Tyr8], as well as the shape of residues [Lys1] and [Pro4]. The potencies of most full-length peptides were well predicted using the leave-one-out procedure, as were the potencies of a series of model Ala-substituted BUFs, thus emphasising the potential utility of these equations in the design of new ligands interacting with tachykinin receptors. PMID:15627485

Liu, Lu; Murray, Michael; Conlon, J Michael; Burcher, Elizabeth

2005-01-15

115

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

International Nuclear Information System (INIS)

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

116

Genetic structure and origin of a tetraploid toad species Bufo danatensis Pisanetz, 1978 (Amphibia, Bufonidae) from central Asia: Description of biochemical polymorphism and comparison of heterozygosity levels in diploid and tetraploid species  

Energy Technology Data Exchange (ETDEWEB)

Comparison of individual variation at 24 biochemical loci in members of the species complex of Palearctic green toads showed that the heterozygosity of the tetraploid species Bufo danatensis (H{sub obs} = 0.45) was significantly higher than that of the diploid species B. viridis, B. sp., and B. raddei (H{sub obs} = 0.009 - 0.103). Such difference can be explained only by a hybrid origin of the tetraploid species. Individual electrophoretic variability of the polyploid toad species is associated with an allelic variation that is manifested in constantly heterozygous spectra as the gene dosage effect. At the population level, this phenomenon found in Pamir toads is caused by irregular meiosis in founders of the population or by directional changes in gene regulation. Genotypic distributions in zones of contact of the diploid and tetraploid taxons demonstrate the possibility of restricted introgressive hybridization.

Mezhzherin, S.V.; Pisanets, E.M. [Schmalhausen Institute of Zoology, Kiev (Ukraine)

1995-01-01

117

[Genetic structure and origin of the tetraploid toad Bufo danatensis Pisanetz, 1978 (Amphibia, Bufonidae) from Central Asia. Biochemical polymorphism and comparison of the level of heterozygosity of diploid species with tetraploid species].  

Science.gov (United States)

Comparison of individual variation at 24 biochemical loci in members of the species complex of Palearctic green toads showed that the heterozygosity of the tetraploid species Bufo danatensis (Hobs + 0.45) was significantly higher than that of the diploid species B. viridis, B. sp., and B. raddei (Hobs = 0.009 - 0.103). Such difference can be explained only by a hybrid origin of the tetraploid species. Individual electrophoretic variability of the polyploid toad species is associated with an allelic variation that is manifested in constantly heterozygous spectra as the gene dosage effect. At the population level, this phenomenon found in Pamir toads is caused by irregular meiosis in founders of the population or by directional changes in gene regulation. Genotypic distributions in zones of contact of the diploid and tetraploid taxons demonstrate the possibility of restricted introgressive hybridization. PMID:7896129

Mezhzherin, S V; Pisanets, E M

1995-01-01

118

Ventilatory behaviors of the toad Bufo marinus revealed by coherence analysis Padrões respiratórios do anfíbio Bufo marinus revelados por análise de coerência  

Directory of Open Access Journals (Sweden)

Full Text Available Breathing in amphibians is a remarkably complex behavior consisting of irregular breaths that may be taken singly or in bouts that are used to deflate and inflate the lungs. The valves at the two outlets of the buccal cavity (nares and glottis need to be finely controlled throughout the bout for the expression of these complex respiratory behaviors. In this study, we use a technique based on the calculation of the coherence spectra between respiratory variables (buccal pressure; narial airflow; and lung pressure. Coherence was also used to quantify the effects of chemoreceptor and pulmonary mechanoreceptor input on narial and glottal valve behavior on normoxic, hypoxic, and hypercapnic toads with both intact and bilaterally sectioned pulmonary vagi. We found a significant reduction in narial coherence in hypoxic vagotomized toads indicating that pulmonary mechanoreceptor feedback modulates narial opening duration. An unexpectedly high coherence between Pl and Pb during non-respiratory buccal oscillations in hypercapnic toads indicated more forceful use of the buccal pump. We concluded that the coherence function reveals behaviors that are not apparent through visual inspection of ventilatory time series.A dinâmica respiratória em anfíbios apresenta um padrão complexo e irregular de episódios respiratórios isolados ou em cadeia utilizados para inflar ou desinflar os pulmões. A dinâmica respiratória depende do controle fino e coordenado das duas saídas da cavidade bucal (glote e válvulas nasais. Neste estudo, utilizamos análise de coerência, uma técnica de análise spectral, para analisar o espectro de coerência entre três variáveis respiratórias: pressão bucal, fluxo de ar nasal e pressão pulmonar. Também quantificamos os efeitos do quimiorreceptor e do mecanorreceptor pulmonar no comportamento da glote e das válvulas nasais em sapos normóxicos, hipóxicos e hipercápnicos com os ramos pulmonares do nervo vago intactos e bilateralmente seccionados. Esta análise revela comportamentos respiratórios não aparentes pelo método tradicional de inspeção visual dos dados. Por exemplo, uma redução significativa da coerência nasal em sapos hipóxicos vagotomizados foi observada, sugerindo a existência de retroalimentação do mecanorreceptor pulmonar que modula a duração da abertura nasal. Uma coerência surpreendentemente alta entre P1 e Pb durante a hipercapnia indica uso mais intenso da bomba bucal. Concluímos que a utilização da função de coerência revela comportamentos não distinguíveis durante a inspeção visual das séries temporais ventilatórias.

F. C. Coelho

2003-02-01

119

Ventilatory behaviors of the toad Bufo marinus revealed by coherence analysis / Padrões respiratórios do anfíbio Bufo marinus revelados por análise de coerência  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A dinâmica respiratória em anfíbios apresenta um padrão complexo e irregular de episódios respiratórios isolados ou em cadeia utilizados para inflar ou desinflar os pulmões. A dinâmica respiratória depende do controle fino e coordenado das duas saídas da cavidade bucal (glote e válvulas nasais). Nes [...] te estudo, utilizamos análise de coerência, uma técnica de análise spectral, para analisar o espectro de coerência entre três variáveis respiratórias: pressão bucal, fluxo de ar nasal e pressão pulmonar. Também quantificamos os efeitos do quimiorreceptor e do mecanorreceptor pulmonar no comportamento da glote e das válvulas nasais em sapos normóxicos, hipóxicos e hipercápnicos com os ramos pulmonares do nervo vago intactos e bilateralmente seccionados. Esta análise revela comportamentos respiratórios não aparentes pelo método tradicional de inspeção visual dos dados. Por exemplo, uma redução significativa da coerência nasal em sapos hipóxicos vagotomizados foi observada, sugerindo a existência de retroalimentação do mecanorreceptor pulmonar que modula a duração da abertura nasal. Uma coerência surpreendentemente alta entre P1 e Pb durante a hipercapnia indica uso mais intenso da bomba bucal. Concluímos que a utilização da função de coerência revela comportamentos não distinguíveis durante a inspeção visual das séries temporais ventilatórias. Abstract in english Breathing in amphibians is a remarkably complex behavior consisting of irregular breaths that may be taken singly or in bouts that are used to deflate and inflate the lungs. The valves at the two outlets of the buccal cavity (nares and glottis) need to be finely controlled throughout the bout for th [...] e expression of these complex respiratory behaviors. In this study, we use a technique based on the calculation of the coherence spectra between respiratory variables (buccal pressure; narial airflow; and lung pressure). Coherence was also used to quantify the effects of chemoreceptor and pulmonary mechanoreceptor input on narial and glottal valve behavior on normoxic, hypoxic, and hypercapnic toads with both intact and bilaterally sectioned pulmonary vagi. We found a significant reduction in narial coherence in hypoxic vagotomized toads indicating that pulmonary mechanoreceptor feedback modulates narial opening duration. An unexpectedly high coherence between Pl and Pb during non-respiratory buccal oscillations in hypercapnic toads indicated more forceful use of the buccal pump. We concluded that the coherence function reveals behaviors that are not apparent through visual inspection of ventilatory time series.

F. C., Coelho; T. L., Baker; N. J., Smatresk.

120

Structure-activity studies of bufokinin, substance P and their C-terminal fragments at bufokinin receptors in the small intestine of the cane toad, Bufo marinus.  

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Bufokinin is a substance P-related tachykinin peptide with potent spasmogenic actions, isolated from the intestine of the cane toad, Bufo marinus. Bufokinin acts via a tachykinin receptor with similarities to the mammalian NK(1) receptor. In this structure-activity study of bufokinin, substance P (SP) and their C-terminal fragments, we have used isolated segments and homogenates of toad small intestine to compare the contractile potencies and abilities to compete for the binding of [125I]-Bolton-Hunter bufokinin. In general, potency was very similar in both studies (r=0.956) and was primarily related to peptide length, with the natural undecapeptide tachykinins bufokinin - ranakinin>SP- cod SP -trout SP being most potent. The weakest peptides were [Pro(9)]SP, BUF(7-11) and SP(7-11). Bufokinin fragments (BUF) were approximately equipotent to the corresponding SP fragments, with only BUF(5-11) showing unexpectedly low binding affinity. Data obtained with SP, bufokinin and fragments were subjected to quantitative structure--activity (QSAR) analysis which demonstrated that molecular connectivity and shape descriptors yielded significant regression equations (r approximately 0.90). The predictive capacity of the equations was confirmed using ranakinin, trout SP and cod SP, but not using the synthetic analogs [Pro(9)]SP and [Sar(9)]SP. The study suggests that the full undecapeptide sequence of bufokinin is required for optimal activity, with high potency conferred by Lys(1), Pro(2), Gly(9) and probably Tyr(8). The finding that receptor-ligand interactions were correlated with the shape descriptor 2kappa(alpha) and favored by basic and rigid residues at position 1-3 is consistent with an important role of conformation at the N-terminus of bufokinin. PMID:11841796

Liu, Lu; Murray, Michael; Burcher, Elizabeth

2002-01-15

 
 
 
 
121

Pawedness and motor asymmetries in toads.  

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Pawedness was investigated in three species of toads, Bufo bufo , Bufo viridis , and Bufo marinus. Samples from natural populations were collected in two successive years and tested during attempts to remove a strip of paper stuck onto the snout ( Bufo bufo and Bufo viridis ) or during attempts to remove an elastic balloon wrapped around the head ( Bufo bufo ). A preferential right forelimb use at the population level was observed in Bufo bufo in both tests, whereas no clear pawedness was observed in Bufo viridis. Bufo marinus also showed no laterality in the paper-strip test, but it appeared to be strongly lateralised in another test that investigated which side the toad rotated when turned on its back underwater. Preferentially turning to the toad's left side as part of a righting response, Bufo marinus released the left forelimb first, using the right forelimb to control the roll to the upright position, and push to the surface. These results suggest that preferential limb use has a long evolutionary history, which dates back to early tetrapods. PMID:15513053

Bisazza, A; Cantalupo, C; Robins, A; Rogers, L J; Vallortigara, G

1997-01-01

122

Evolution of mitochondrial relationships and biogeography of Palearctic green toads (Bufo viridis subgroup) with insights in their genomic plasticity.  

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Taxa involving three bisexually reproducing ploidy levels make green toads a unique amphibian system. We put a cytogenetic dataset from Central Asia in a molecular framework and apply phylogenetic and demographic methods to data from the entire Palearctic range. We study the mitochondrial relationships of diploids to infer their phylogeography and the maternal ancestry of polyploids. Control regions (and tRNAs between ND1 and ND2 in representatives) characterize a deeply branched assemblage of twelve haplotype groups, diverged since the Lower Miocene. Polyploidy has evolved several times: Central Asian tetraploids (B. oblongus, B. pewzowi) have at least two maternal origins. Intriguingly, the mitochondrial ancestor of morphologically distinctive, sexually reproducing triploid taxa (B. pseudoraddei) from Karakoram and Hindukush represents a different lineage. We report another potential case of bisexual triploid toads (B. zugmayeri). Identical d-loops in diploids and tetraploids from Iran and Turkmenistan, which differ in morphology, karyotypes and calls, suggest multiple origins and retained polymorphism and/or hybridization. A similar system involves diploids, triploids and tetraploids from Kyrgyzstan and Kazakhstan where green toads exemplify vertebrate genomic plasticity. A new form from Sicily and its African sister species (B. boulengeri) allow internal calibration and divergence time estimates for major clades. The subgroup may have originated in Eurasia rather than Africa since the earliest diverged lineages (B. latastii, B. surdus) and earliest fossils occur in Asia. We delineate ranges, contact and hybrid zones. Phylogeography, including one of the first non-avian datasets from Central Asian high mountains, reflects Quaternary climate and glaciation. PMID:16919484

Stöck, Matthias; Moritz, Craig; Hickerson, Michael; Frynta, Daniel; Dujsebayeva, Tatjana; Eremchenko, Valery; Macey, J Robert; Papenfuss, Theodore J; Wake, David B

2006-12-01

123

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

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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.

Perrin Nicolas

2010-07-01

124

Inferring the degree of incipient speciation in secondary contact zones of closely related lineages of Palearctic green toads (Bufo viridis subgroup).  

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Reproductive isolation between lineages is expected to accumulate with divergence time, but the time taken to speciate may strongly vary between different groups of organisms. In anuran amphibians, laboratory crosses can still produce viable hybrid offspring >20 My after separation, but the speed of speciation in closely related anuran lineages under natural conditions is poorly studied. Palearctic green toads (Bufo viridis subgroup) offer an excellent system to address this question, comprising several lineages that arose at different times and form secondary contact zones. Using mitochondrial and nuclear markers, we previously demonstrated that in Sicily, B. siculus and B. balearicus developed advanced reproductive isolation after Plio-Pleistocene divergence (2.6 My, 3.3-1.9), with limited historic mtDNA introgression, scarce nuclear admixture, but low, if any, current gene flow. Here, we study genetic interactions between younger lineages of early Pleistocene divergence (1.9 My, 2.5-1.3) in northeastern Italy (B. balearicus, B. viridis). We find significantly more, asymmetric nuclear and wider, differential mtDNA introgression. The population structure seems to be molded by geographic distance and barriers (rivers), much more than by intrinsic genomic incompatibilities. These differences of hybridization between zones may be partly explained by differences in the duration of previous isolation. Scattered research on other anurans suggests that wide hybrid zones with strong introgression may develop when secondary contacts occur <2 My after divergence, whereas narrower zones with restricted gene flow form when divergence exceeds 3 My. Our study strengthens support for this rule of thumb by comparing lineages with different divergence times within the same radiation. PMID:24713825

Dufresnes, C; Bonato, L; Novarini, N; Betto-Colliard, C; Perrin, N; Stöck, M

2014-07-01

125

Chronic effects of strobilurin fungicides on development, growth, and mortality of larval Great Plains toads (Bufo cognatus).  

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Agricultural fungicide application has increased tenfold since 2005 in the United States. Active ingredients and formulations of strobilurin fungicides at environmentally relevant concentrations cause mortality to larval and metamorph amphibians; however, little is known about chronic exposure effects in amphibians. We exposed larval amphibians (Bufo cognatus) throughout metamorphosis to the common fungicide formulations Headline(®), Stratego(®), Quilt(®), and a control to determine effects on development and growth. Formulations were tested at 1.7, 50, and 400 ?g/L of the active strobilurin ingredient for Headline(®), Stratego(®), and Quilt(®), respectively. Fungicide exposure did not affect body mass or snout-vent length at metamorphosis. However, exposure to Headline(®) at 1.7 ?g/L increased the development rate of tadpoles by approximately 5 days compared to the control, an effect not observed for Stratego(®) and Quilt(®). Stratego(®) also caused approximately 35 % cumulative mortality. Results from the experiment suggest that chronic effects of strobilurin fungicides on development, growth, and mortality to B. cognatus are apparent at environmentally relevant concentrations. PMID:24522617

Hartman, Emily A H; Belden, Jason B; Smith, Loren M; McMurry, Scott T

2014-04-01

126

Oxygen Transport in Amphibia: The Functional Properties of Hemoglobins from Bufo bufo and Bufo viridis  

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Full Text Available The oxygen binding properties of the hemoglobins from two toads, Bufo bufo and Bufo viridis, have been investigated as a function of protons, chloride ions, organic phosphates and temperature. Electrophoretic analysis of the hemolysates showed the presence of a main hemoglobin in each of the two species. We found that the hemoglobin from Bufo bufo shows at 20°C a slight Bohr effect which tends to increase in the presence of the different allosteric effectors (chloride ions and ATP. At 37°C, the effect of protons is completely abolished in all experimental conditions. The Bufo viridis Hb presents a Bohr effect slightly more pronounced (doubled with respect to B. bufo which increases only with the simultaneous presence of modulators, both at 20 and at 37°C. Moreover the overall heats of oxygenation (expressed by ?H values result in the two amphibian hemoglobins much less exothermic than that of the human hemoglobin and in the case of Bufo viridis completely independent by organic phosphate (DPG. These particular features are very interesting because the two hemoglobins seem well adapted to the different habitats and physiological needs characterizing the two toads.

Maria Elisabetta Clementi

2007-01-01

127

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  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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.

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

128

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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.

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

2006-02-01

129

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  

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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.

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

2000-01-01

130

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  

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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.

Lucio Bonato

2010-07-01

131

[Genetic structure and origin of the tetraploid toad Bufo danatensis Pisanetz, 1978 (Amphibia, Bufonidae) of Central Asia. Differentiation of geographic forms and genetic relationship between diploid and tetraploid species].  

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A hierarchical system, consisting of several levels of genetic divergence, is formed by distribution of genetic distances between diploid taxa of the green toad species complex (subspecies Bufo viridis viridis--B. v. turanensis and species B. viridis--B. sp.) and taxa representing western (B. viridis s.l.) and eastern (B. raddei) Pale-arctic regions. Formally, genetic differentiation of the tetraploid toad B. danatensis from the parapatric diploid species reaches the species level. Genetic diversity of the tetraploid species is more than twofold higher than the total diversity of two modern diploid species. This suggests that B. danatensis was formed with the participation of other unknown species in the past. The polyploid species B. danatensis is assumed to have originated by hybridization of two species groups that arose approximately 2.6 million years ago in Mediterranean and Central Asian regions of the western Palearctic. The genetic heterogeneity of geographical populations of the polyploid species indicates its polyphiletic origin. The heterogeneity range suggests that formation of the tetraploid species continued for a very long period (about 1 million years). PMID:7607424

Mezhzherin, S V; Pisanets, E M

1995-03-01

132

Small frogs get their worms first: the role of nonodonate arthropods in the recruitment of Haematoloechus coloradensis and Haematoloechus complexus in newly metamorphosed northern leopard frogs, Rana pipiens, and woodhouse's toads, Bufo woodhousii.  

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Studies on the life cycles and epizootiology of North American frog lung flukes indicate that most species utilize odonates as second intermediate hosts; adult frogs become infected by ingesting odonate intermediate hosts. Newly metamorphosed frogs are rarely infected with these parasites, predominantly because they are gape-limited predators that cannot feed on large intermediate hosts such as dragonflies. We examined the role of the frog diet and potential intermediate hosts in the recruitment of the frog lung fluke, Haematoloechus coloradensis, to metamorphosed northern leopard frogs (Rana pipiens), Woodhouse's toads (Bufo woodhousii), and bullfrogs (Rana catesbeiana) from western Nebraska. Because of the uncertain validity of H. coloradensis as a distinct species from Haematoloechus complexus, morphological characters of both species were reevaluated and the life cycles of both species were completed in the laboratory. The morphological data on H. coloradensis and H. coimplexus indicate that they differ in their oral sucker to pharynx ratio, uterine loop distribution, and placement of vitelline follicles. However, in terms of their life cycles, both species are quite similar in their use of physid snails as first intermediate hosts, a wide range of nonodonate and odonate arthropods as second intermediate hosts, and leopard frogs and toads as definitive hosts. These results indicate that H. coloradensis and H. complexus are generalists at the second intermediate host level and might be able to infect newly metamorphosed leopard frogs and toads by using small nonodonate arthropods more commonly than other frog lung fluke species. Comparisons of population structure of adult flukes in newly metamorphosed leopard frogs indicate that the generalist nature of H. coloradensis metacercariae enables it to colonize young of the year leopard frogs more commonly than other Haematoloechus spp. that only use odonates as second intermediate hosts. In this respect, the generalist nature of H. coloradensis and H. complexus at the second intermediate host level is an avenue for the colonization of young of year frogs. PMID:17539412

Bolek, Matthew G; Janovy, John

2007-04-01

133

How complex is the Bufo bufo species group?  

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Species delineation remains one of the most challenging tasks in the study of biodiversity, mostly owing to the application of different species concepts, which results in contrasting taxonomic arrangements. This has important practical consequences, since species are basic units in fields like ecology and conservation biology. We here review molecular genetic evidence relevant to the systematics of toads in the Bufo bufo species group (Anura, Bufonidae). Two studies recently published in this journal (Recuero et al., MPE 62: 71-86 and Garci?a-Porta et al., MPE 63: 113-130) addressed this issue but reached opposing conclusions on the taxonomy of the group (four versus two species). In particular, allozyme data in the latter paper were interpreted as evidence for hybridization across species (between B. bufo-B. spinosus and B. bufo-B. verrucosissimus). We tested claims for hybridization through re-analysis of allozyme data for individuals instead of populations, to be able to distinguish between sympatry with and without admixture, and found no evidence of hybridization across taxa. We propose alternative explanations for the observed patterns that Garci?a-Porta et al. (2012) failed to consider. In the absence of unequivocal evidence for hybridization and introgression, we reject the proposal to downgrade Bufo spinosus and Bufo verrucosissimus to the subspecies level. PMID:23880535

Arntzen, Jan W; Recuero, Ernesto; Canestrelli, Daniele; Martínez-Solano, Iñigo

2013-12-01

134

New geographical records of parasitic nematodes from Bufo bufo in Italy.  

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To provide information on parasites of Bufo bufo (toad), eyes, skin, lungs, gut and urinary bladder of individuals collected near lakes Endine and Segrino (Northern Italy) from March to April 1999 were recorded in laboratory. A total of five nematode species were classified: Oswaldocruzia filiformis, Oxysomatium brevicaudatum, Cosmocerca ornata, Neyraplectana schneideri were found in the intestine and rectum and Rhabdias sphaerocephala in the lungs. Of these species, the last three are new geographical records for Italy. PMID:12402520

Galli, P; Crosa, G; Gentilli, A; Santagostino, M

2001-12-01

135

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

Scientific Electronic Library Online (English)

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

Mario, Lo Valvo; Gabriele, Giacalone.

2013-06-01

136

Lateralisation of predator avoidance responses in three species of toads.  

Science.gov (United States)

Lateralisation of responses to presentation of a simulated predator was investigated in three species of toads: two European species (the common toad, Bufo bufo, and the green toad, Bufo viridis) and one species introduced to Australia from South America, the cane toad Bufo marinus . First a simulated snake was presented moving rapidly towards the toad in the frontal field of vision and the toad's escape responses, including jumps to the right and to the left, were recorded. No significant bias in left or right side jumping was apparent in this test. Next the simulated snake was presented in the left or right lateral field of vision in random order. Escape and defensive responses were elicited more strongly, in all three species, when the stimulus was on the toad's left side compared to its right side. Reaction times scored in the experiments with B. marinus, alone, did not differ from left to right. There were, however, species differences in the types of escape responses with respect to the laterality: B. viridis and B. marinus showed similar patterns of more sideways jumps with left presentation and more frontal jumps with right presentation. Sideways jumps were not lateralised in B. bufo, but this species showed more frontal jumps when the presentation was on the left side. These findings suggest that the selective involvement of structures located in the right side of the brain (left monocular visual field) in emotional responses (particularly fear responses) could be a phylogenetic ancient trait. PMID:15513195

Lippolis, Giuseppe; Bisazza, Angelo; Rogers, Lesley J; Vallortigara, Giorgio

2002-01-01

137

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

Directory of Open Access Journals (Sweden)

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.

Handan Karaoglu

2011-01-01

138

Low rates of X-Y recombination, not turnovers, account for homomorphic sex chromosomes in several diploid species of Palearctic green toads (Bufo viridis subgroup).  

Science.gov (United States)

Contrasting with birds and mammals, most ectothermic vertebrates present homomorphic sex chromosomes, which might be due either to a high turnover rate or to occasional X-Y recombination. We tested these two hypotheses in a group of Palearctic green toads that diverged some 3.3 million years ago. Using sibship analyses of sex-linked markers, we show that all four species investigated share the same pair of sex chromosomes and a pattern of male heterogamety with drastically reduced X-Y recombination in males. Phylogenetic analyses of sex-linked sequences show that X and Y alleles cluster by species, not by gametolog. We conclude that X-Y homomorphy and fine-scale sequence similarity in these species do not stem from recent sex-chromosome turnovers, but from occasional X-Y recombination. PMID:23316809

Stöck, M; Savary, R; Betto-Colliard, C; Biollay, S; Jourdan-Pineau, H; Perrin, N

2013-03-01

139

Acanthocephalus bufonis (Acanthocephala) from Bufo marinus (Bufonidae: Amphibia) in Hawaii.  

Science.gov (United States)

During a survey of the helminth parasites of the introduced toad, Bufo marinus, on O'ahu, Hawaii, an acanthocephalan corresponding to Acanthocephalus bufonis (Shipley, 1903) was found in the intestinal tract. This is a new host and locality record for A. bufonis which has only previously been recorded from amphibians in the Orient. Possible mechanisms for the introduction of A. bufonis to Hawaii, and its transmission to the toad, are discussed. Almost 98% of toads were infected with a mean intensity of 28.6 acanthocephalans per infected toad. There was a significant negative correlation between host length and intensity of infection with subadult toads having significantly higher infection levels than adult male and female toads. Trunk length of both male and female acanthocephalans was significantly related to host length. PMID:10511976

Barton, D P; Pichelin, S

1999-09-01

140

Clinostomum attenuatum (Digenea) from the eye of Bufo marinus.  

Science.gov (United States)

Two specimens of the cane toad, Bufo marinus, were found with single worm infestations of the eye. One worm was excysted in the eye chamber, the other still encysted in the choroid layer; both worms were identified as Clinostomum attenuatum. This finding is both a new host record and a new site of development for this amphibian parasite. PMID:1907655

Etges, F J

1991-08-01

 
 
 
 
141

Habitat use and movements of repatriated Wyoming toads  

Science.gov (United States)

We studied habitat use and movements of a repatriated population of federally endangered Wyoming toads (Bufo baxteri) after the breeding season at Mortenson Lake, Albany County, Wyoming, USA. We followed 8 adult toads using telemetry (n = 68 relocations) during periods of activity and observed 59 post-metamorphic juvenile toads (n = 59 locations). Adult toads used habitat with a greater mean vegetation canopy cover (mean = 52.6%) than juveniles (mean = 39.20%). We found adults farther from the shoreline (mean = 1.32 m) than juveniles (mean = 1.04 m). Substrates used by toads had a mean surface temperature of 20.31??C for adults and 23.05??C for juveniles. We found most adult and juvenile toads on saturated substrates. All adult toads sampled did not move outside of a 30 x 500 m area along the east-to-south shore where they were captured. Toads were active diurnally through the end of October. We found toads torpid at night. We compared our results to a similar study of the historic population and found that adult toads of the current population used denser vegetation than those of the historic population. Unlike many bufonids, terrestrial stages of the Wyoming toad appear to depend on saturated substrates. The best logistic regression predictors of adult and juvenile toad presence were surface temperature and distance to shore. Survey transects within the moist margin of the lake (???10 m from water) and after substrates have reached temperatures ???20??C will likely yield more detections.

Parker, J. M.; Anderson, S. H.

2003-01-01

142

Lateralized agonistic responses and hindlimb use in toads.  

Science.gov (United States)

The recent discovery of forepaw preferences (handedness) in toad species has provided some insight into the evolution of brain lateralization. We tested the prediction that, as in higher vertebrates, visual lateralization and other motor preferences (footedness) also exists in toad species. During feeding periods, South American cane toads, Bufo marinus, showed a population bias to strike with the tongue at other toads occupying their left visual field. This is the first demonstration of lateralized visual behaviour in an amphibian species. Tongue striking at an individual's eyes or head may sometimes delay its approach to prey already seen by the attacker, or may dislodge prey from its mouth. In addition, we report hindlimb preferences (footedness) for contact righting in three species of toad (B. marinus, the European green toad, B. viridis, and the European common toad, B. bufo). After being fully overturned on to their back on a horizontal surface, toads initiated and completed righting using the hindlimbs and with only perfunctory use of the forepaws. Together, the findings of visual lateralization and footedness demonstrate that in toads, as in higher vertebrates, behavioural lateralization is not restricted to handedness. The hypothesis that lateralized brain functions in birds and mammals might have arisen from a common lateralized ancestor is therefore supported. Copyright 1998 The Association for the Study of Animal Behaviour. PMID:9790698

Robins; Lippolis; Bisazza; Vallortigara; Rogers

1998-10-01

143

TOAD Gateway  

Science.gov (United States)

TOAD Gateway is interactive software tool for converting data files to and from variety of file formats. Currently reads and writes following file formats: TOAD; Standard Interface File (SIF); Program to Optimize Simulated Trajectories (POST) input; Comma Separated Value and Tab Separated Value, common in PC and Macintosh spreadsheet and database packages; and general free format. Additional modules for accommodating other formats easily developed and installed. Companion program, TOAD Editor (LAR-14423), manipulates contents of TOAD files and extracts selected subsets of data. TOAD Gateway written in FORTRAN 77.

Bingel, Bradford D.

1994-01-01

144

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

International Nuclear Information System (INIS)

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

145

Assessment of age and intersexual size differences in Bufo bufo  

Directory of Open Access Journals (Sweden)

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

Cvetkovi? Dragana D.

2005-01-01

146

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

Science.gov (United States)

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.

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

2007-01-01

147

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

International Nuclear Information System (INIS)

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

148

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

Science.gov (United States)

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. PMID:23474321

Bernabò, Ilaria; Bonacci, Antonella; Coscarelli, Francesca; Tripepi, Manuela; Brunelli, Elvira

2013-05-15

149

[Bufadienolides from venom of Bufo bufo gargarizans].  

Science.gov (United States)

Twelve compounds were isolated from the venom of Bufo bufo gargarizans. On the basis of their physical and chemical properties and spectral data, their structures were identified as resibufagenin (1), bufotalin (2), desacetylcinobufagin (3), 19-oxodesacetylcinobufotalin (4), cinobufotalin (5), 1beta-hydroxylbufalin (6), 12alpha-hydroxybufalin (7), bufotalinin (8), Hellebrigenin (9), telocinobufagin (10), hellebrigenol (11) and cinobufagin-3-hemisuberate methyl ester (12), respectively. Compounds 7 and 12 are new natural products. PMID:25204176

Zhang, Peng-Wei; Jiang, Ren-Wang; Ye, Wen-Cai; Tian, Hai-Yan

2014-03-01

150

A deep brain photoreceptive molecule in the toad hypothalamus.  

Science.gov (United States)

We have isolated a cDNA clone encoding a deep brain photoreceptive molecule from the hypothalamic cDNA library of the toad, Bufo japonicus. The deduced amino acid sequence showed the highest similarity to that of pinopsin (75-76%) among vertebrate retinal opsins, indicating the expression of toad pinopsin in the deep brain. Antibodies raised against the C-terminal tail of toad pinopsin stained cell bodies and the knob-like structures of the cerebrospinal fluid-contacting neurons in the anterior preoptic nucleus. This region is known to play an important role in breeding behavior, suggesting that toad pinopsin acts as a photosensor for the photoperiodic gonadal response. PMID:9537517

Yoshikawa, T; Okano, T; Oishi, T; Fukada, Y

1998-03-01

151

Initiation and post-initiation chemopreventive effects of beta-carotene in toad liver carcinogenesis.  

Science.gov (United States)

Hepatocellular carcinoma were recognized in the toad, Bufo viridis, in 14 cases out of 50 by injection of 1 mg 7,12 dimethylbenz(a)anthracene (DMBA)/toad twice/week for 12 weeks. In contrast, toads treated with DMB at the same dose level and beta-carotene (betaC), 0.05 mg (3 hr prior to the carcinogen)/toad, twice/week for 12 weeks showed no tumor incidence. However, betaC at the same dose level was less effective when administered 3 hr. after the carcinogen (DMBA). In 8 cases out of 50 cases neither tumor growth nor neoplastic changes were observed in toads treated with betaC alone or olive oil. It is concluded that betaC completely blocked hepatocarcinogenesis in toads when given 3 hr. before initiation. PMID:8861758

Sadek, I A; Hayat, L G

1996-04-01

152

Chloride channels in toad skin  

DEFF Research Database (Denmark)

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- ions through this pathway. Experimental analysis of the gating kinetics is rendered difficult owing to a contamination of the gated currents by cellular ion redistribution currents. To obtain insight into the effects of accumulation-depletion currents on voltage clamp currents of epithelial membranes, a mathematical model of the epithelium has been developed for computer analysis. By assuming that the apical membrane Cl- permeability is governed by a single gating variable (Hodgkin-Huxley kinetics), the model predicts fairly well steady-state current-voltage curves, the time course of current activations from a closed state, and the dependence of unidirectional fluxes on potential. Other predictions of the model do not agree with experimental findings, and it is suggested that the gating kinetics are governed by rate coefficients that also depend on the holding potential. Evidence is presented that Cl- transport through open channels does not obey the constant-field equation.

Larsen, Erik Hviid; Rasmussen, B E

1982-01-01

153

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

International Nuclear Information System (INIS)

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

154

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

Science.gov (United States)

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

Jourdane, J; Theron, A

1975-01-01

155

WHEN A PHYLOGENETIC TRICHOTOMY MAKES SENSES: PHYLOGEOGRAPHY OF BUFO PUNCTATUS AND THE EVOLUTION OF THE WARM DESERTS  

Science.gov (United States)

Bufo punctatus, the red-spotted toad, is a common, desert-adapted anuran with a widespread distribution throughout warm, and regions of North America. This distribution makes this species ideal for evaluating alternative scenarios of biotic response to geotectonically and climat...

156

PHYLOGEOGRAPHY OF BUFO PUNCTATUS: LONG TERM EVOLUTION WITHIN THE WARM DESERTS OF NORTH AMERICA AND LATE QUATERNARY RANGE SHIFTING  

Science.gov (United States)

Bufo punctatus, the red-spotted toad, is a widespread anuran of the warm-desert regions of western North America. This distribution makes this species ideal for evaluating biotic response to geotectonically and climatically mediated episodes of landscape transformation (e.g., ear...

157

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

158

Effects of an invasive plant on population dynamics in toads.  

Science.gov (United States)

When populations decline in response to unfavorable environmental change, the dynamics of their population growth shift. In populations that normally exhibit high levels of variation in recruitment and abundance, as do many amphibians, declines may be difficult to identify from natural fluctuations in abundance. However, the onset of declines may be evident from changes in population growth rate in sufficiently long time series of population data. With data from 23 years of study of a population of Fowler's toad (Anaxyrus [ = Bufo] fowleri) at Long Point, Ontario (1989-2011), we sought to identify such a shift in dynamics. We tested for trends in abundance to detect a change point in population dynamics and then tested among competing population models to identify associated intrinsic and extrinsic factors. The most informative models of population growth included terms for toad abundance and the extent of an invasive marsh plant, the common reed (Phragmites australis), throughout the toads' marshland breeding areas. Our results showed density-dependent growth in the toad population from 1989 through 2002. After 2002, however, we found progressive population decline in the toads associated with the spread of common reeds and consequent loss of toad breeding habitat. This resulted in reduced recruitment and population growth despite the lack of significant loss of adult habitat. Our results underscore the value of using long-term time series to identify shifts in population dynamics coincident with the advent of population decline. PMID:23692126

Greenberg, Daniel A; Green, David M

2013-10-01

159

Trypanosoma mega (Kinetoplastida) from Bufo viridis in Siwah Oasis, Egypt.  

Science.gov (United States)

A large pleomorphic trypanosome, identified as Trypanosoma mega, is described from the toad Bufo viridis collected from Siwah Oasis at the Western Desert of Egypt. The prevalence of the trypanosome is 83.3%. Three trypanosome forms are described, small, intermediate and large stumpy form. Observations were also made on the lysed (diffused) trypanosomes. This is the first record of T. mega from B. viridis in Egypt which represents a new host and new geographical location. The measurements of the present trypanosome are given and compared with related forms previously described from Egypt. PMID:9097527

Ashour, A A; Gaafar, N A

1997-04-01

160

Toad envenoming in dogs: effects and treatment  

Scientific Electronic Library Online (English)

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

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

 
 
 
 
161

Toad envenoming in dogs: effects and treatment  

Directory of Open Access Journals (Sweden)

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.

M. SAKATE

2000-01-01

162

LOCAL SCALE FACTORS DETERMINE HABITAT PATCH OCCUPANCY BY RED-SPOTTED TOADS IN A NATURALLY FRAGMENTED DESERT LANDSCAPE  

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

163

Endosulfan acute toxicity in Bufo bufo gills: Ultrastructural changes and nitric oxide synthase localization  

Energy Technology Data Exchange (ETDEWEB)

Endosulfan is an organochlorine pesticide used in agriculture for a wide range of crops. Endosulfan concentrations of up to 0.7 mg/L can be found in ponds and streams near sprayed agricultural fields. We investigated the short-term toxicity of endosulfan in common toad (Bufo bufo) tadpoles after 24, 48, and 96 h of exposure. Acute toxicity was evaluated at nominal concentrations ranging from 0.01 to 0.6 mg/L: concentrations that could be found after the application of pesticide. Our results show that 0.43 mg/L of endosulfan caused 50% mortality (LC{sub 50}). The effects of a sublethal endosulfan concentration (0.2 mg/L) on gill apparatus morphology were evaluated by scanning and transmission electron microscopy. Immunohistochemical methods were also applied to detect the expression pattern of the inducible isoform of nitric oxide synthase (iNOS) in the gills using the confocal laser scanner microscope. Exposure to 0.2 mg/L of endosulfan caused an apparent increase in mucus production, the occurrence of secretory vesicles and lamellar bodies, a widening of intercellular spaces and additionally there was evidence of an inflammatory response in the gill apparatus. The morphological alterations occurred after 24 h and were more pronounced after 48 and 96 h of exposure. Altered morphology and increased mucus secretion indicate impaired gas exchange and osmoregulation in the gills. In addition, there was an increase of iNOS expression after 24 and 48 h which may reflect hypoxia and inflammation in the gill epithelium. Our results clearly indicate that short-term exposure to a sublethal concentration of endosulfan, near the high end of the environmental range, disrupts gill morphology and function in B. bufo tadpoles.

Bernabo, Ilaria [Department of Ecology, University of Calabria, Via P. Bucci, 87036 Rende (Cosenza) (Italy); Brunelli, Elvira [Department of Ecology, University of Calabria, Via P. Bucci, 87036 Rende (Cosenza) (Italy)], E-mail: brunelli@unical.it; Berg, Cecilia [Department of Environmental Toxicology, Uppsala University, Norbyvagen 18A, 752 36 Uppsala (Sweden); Bonacci, Antonella; Tripepi, Sandro [Department of Ecology, University of Calabria, Via P. Bucci, 87036 Rende (Cosenza) (Italy)

2008-02-18

164

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

Science.gov (United States)

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

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

2011-02-01

165

Predicting the unpredictable; evidence of pre-seismic anticipatory behaviour in the common toad  

Science.gov (United States)

The widespread belief that animals can anticipate earthquakes (EQs) is poorly supported by evidence, most of which consists of anecdotal post hoc recollections and relates to a very short period immediately before such events. In this study, a population of reproductively active common toads Bufo bufo were monitored over a period of 29 days, before, during and after the EQ (on day 10) at L'Aquila, Italy, in April 2009. Although our study site is 74 km from L'Aquila, toads showed a dramatic change in behaviour 5 days before the EQ, abandoning spawning and not resuming normal behaviour until some days after the event. It is unclear what environmental stimuli the toads were responding to so far in advance of the EQ, but reduced toad activity coincides with pre-seismic perturbations in the ionosphere, detected by very low frequency (VLF) radio sounding. We compare the response of toads to the EQ with the reported responses to seismic activity of several other species.

Grant, Rachel A.; Halliday, T.

2010-08-01

166

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  

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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.

Lourival Pereira Nunes

2007-09-01

167

Infestação de Amblyomma rotundatum (Koch) (Acari, Ixodidae) em sapos Bufo ictericus (Spix) (Amphibia, Bufonidae): novo registro de hospedeiro / Infestation of Amblyomma rotundatum (Koch) (Acari, Ixodidae) ticks on Bufo ictericus (Spix) (Amphibia, Bufonidae): new host record  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese [...] Abstract in english Bufo ictericus Spix, 1824 toad population (N = 125) foraging in lighted areas in the Corupá Municipality, Santa Catarina State, was surveyed to evaluate the prevalence (percentage of infestation) and the mean infestation intensity of Amblyomma rotundatum Koch, 1844 (Acari, Ixodidae) ticks. The preva [...] lence was of 19.2% and the mean infestation intensity was 7.4 ticks per infested toad. For the first time B. ictericus as host of A. rotundatum is reported.

Germano, Woehl Jr..

168

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

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Urea is actively transported inwardly (J{sub i}) across the skin of the green toad Bufo viridis. J{sub i} 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{sup {minus}4} M) significantly inhibited J{sub i} in both adapted and unadapted animals and was unaffected by removal of sodium from the external medium. Phloretin (10{sup {minus}4} M) significantly inhibited J{sub i} in adapted animals by 23-46%; there was also a reduction in J{sub i} in unadapted toads at 10{sup {minus}4} and 5 {times} 10{sup {minus}4} M phloretin. A dose-response study revealed that the concentration of phloretin causing half-maximal inhibition (K{sub {1/2}}) was 5 {times} 10{sup {minus}4} M for adapted animals. J{sub i} 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 J{sub i} is independent of sodium transport.

Rapoport, J.; Abuful, A.; Chaimovitz, C.; Noeh, Z.; Hays, R.M. (Soroka Medical Center, Beersheva (Israel) Albert Einstein College of Medicine, New York, NY (USA))

1988-09-01

169

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

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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.

Gollmann Günter

2011-03-01

170

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

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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

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

2004-01-01

171

Influence of lung parasites on the growth rates of free-ranging and captive adult cane toads.  

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Many parasites affect the viability of their hosts, but detailed studies combining empirical data from both the field and the laboratory are limited. Consequently, the nature and magnitude of such effects are poorly known for many important host-parasite systems, including macroparasites of amphibians. We examined the effects of lungworm (Rhabdias pseudosphaerocephala) infections in cane toads (Bufo marinus) within their invasive Australian range. The host-specificity of this parasite suggests that it might serve as a biological control agent for toads in Australia, if infection proves to reduce toad viability. Mark-recapture studies in the field (near Darwin, Northern Territory) revealed lowered growth rates in infected adult toads when compared to uninfected toads, and a laboratory experiment confirmed causality: experimental infection with R. pseudosphaerocephala reduce toad growth rates. In combination with previous work on the current host-parasite system, it is now evident that nematode lungworms reduce the viability of both newly metamorphosed and adult cane toads, and do so in the field as well as in the laboratory. Rhabdias pseudosphaerocephala may be a valuable component of a biological control strategy for cane toads in Australia. PMID:21076965

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

2011-03-01

172

Ouabain-sensitive Na+,K(+)-ATPase activity in toad brain.  

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Toads of the genus Bufo are highly resistant to the toxic effects of digitalis glycosides, and the Na+,K(+)-ATPase of all toad tissues studied to date has been relatively insensitive to inhibition by digitalis and related compounds. In studies of brain microsomal preparations from two toad species, Bufo marinus and Bufo viridis, inhibition of ATPase activity and displacement of [3H]ouabain from Na+,K(+)-ATPase occurred over broad ranges of ouabain or bufalin concentrations, consistent with the possibility that more than one Na+,K(+)-ATPase isoform may be present in toad brain. The data could be fitted to one- or two-site models, both of which were consistent with the presence of Na+,K(+)-ATPase activity with high sensitivity to ouabain and bufalin. Ki (concentration capable of producing 50% inhibition of activity) values for ouabain in the one-site model were in the 0.2 to 3.7 microM range, whereas Ki1 values in the two-site model ranged from 0.085 to 0.85 microM, indicating that brain ATPase was at least three orders of magnitude more sensitive to ouabain than B. marinus bladder ATPase (Ki = 5940 microM). Ouabain was also an effective inhibitor of 86Rb+ uptake in B. marinus brain tissue slices (Ki = 3.1 microM in the one-site model; Ki1 = 0.03 microM in the two-site model). However, the relative contribution of the high ouabain-sensitivity site to the total activity was 17% in the transport assay as compared with 63% in the Na+,K(+)-ATPase enzymatic assay. We conclude that a highly ouabain-sensitive Na+,K(+)-ATPase activity is present and functional in toad brain but that its function may be partially inhibited in vivo. PMID:9406436

Morris, J F; Ismail-Beigi, F; Butler, V P; Gati, I; Lichtstein, D

1997-11-01

173

Multiple origins of tetraploid taxa in the Eurasian Bufo viridis subgroup.  

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We used Q-banding and analyzed nucleolar organizing regions (NORs) to study the cytogenetic evolution of tetraploids within the Palearctic Bufo viridis subgroup, the only known amphibian complex comprising di-, tri- and tetraploid bisexually reproducing taxa. We examined three diploid (2n) nominal taxa (Bufo viridis viridis, B. v. turanensis, B. v. kermanensis) from five Eurasian localities and six tetraploid (4n) nominal taxa (B. oblongus, B. o. danatensis, B. pewzowi pewzowi, B. p. taxkorensis, B. p. unicolor, B. p. strauchi) from eight Central Asian localities. Homeologous chromosomes of 2n and 4n toads exhibit a similar morphology. Silver-staining and in situ hybridization revealed terminal NORs in the long arms of chromosomes 6 in all 2n but in only two out of four chromosomes 6 in all 4n taxa. Q-banding and a rapidly evolving mitochondrial marker suggest at least two origination events for Asian 4n toads: "Western Central Asian tetraploids" (B. oblongus Nikolsky, 1896) exhibit distinct differences within some chromosome quartets, which are divisible into pairs of chromosomes and may be allopolyploid. In contrast, "Central Asian tetraploids" (B. pewzowi Bedriaga, 1898) showed homogenous Q-banding patterns within each quartet, suggesting autopolyploidy. In Northeastern Iran, we discovered a zone of either common ancestry or hybridization of 2n and Western Central Asian 4n toads. This raises intriguing questions about how diploid and tetraploid taxa may evolve by exchanging genetic material. PMID:16134338

Stöck, Matthias; Steinlein, Claus; Lamatsch, Dunja K; Schartl, Manfred; Schmid, Michael

2005-07-01

174

Breeding phenology of Bufo viridis Laurenti, 1768 in Sicily  

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Full Text Available Bufo viridis Laurenti, 1768 is a common species that inhabits a wide variety of habitats. The different climates characterising its broad range lead to a high degree of variability in its seasonal activity and reproductive cycle. This paper reports some observations carried out on the breeding phenology of this species over a two year period in Mediterranean temporary ponds in Sicily. The reproductive period of Sicilian green toads extends into the autumn months, making it longer than that of other Italian populations. This behaviour seems due to the impact of xeric environmental conditions on the seasonal activity of the studied populations. The present study confirms that B. viridis is an opportunistic breeder with a wide margin of variability in annual reproductive cycle patterns, as would be expected of an ecologically variable species. The duration of the reproductive season varied between populations in the same year and between different years for the same population.

Francesco Lillo

2006-11-01

175

Toad glandular secretions and skin extractions as anti-inflammatory and anticancer agents.  

Science.gov (United States)

Toad glandular secretions and skin extractions contain many natural agents which may provide a unique resource for novel drug development. The dried secretion from the auricular and skin glands of Chinese toad (Bufo bufo gargarizans) is named Chansu, which has been used in Traditional Chinese Medicine (TCM) for treating infection and inflammation for hundreds of years. The sterilized hot water extraction of dried toad skin is named Huachansu (Cinobufacini) which was developed for treating hepatitis B virus (HBV) and several types of cancers. However, the mechanisms of action of Chansu, Huachansu, and their constituents within are not well reported. Existing studies have suggested that their anti-inflammation and anticancer potential were via targeting Nuclear Factor (NF)-?B and its signalling pathways which are crucial hallmarks of inflammation and cancer in various experimental models. Here, we review some current studies of Chansu, Huachansu, and their compounds in terms of their use as both anti-inflammatory and anticancer agents. We also explored the potential use of toad glandular secretions and skin extractions as alternate resources for treating human cancers in combinational therapies. PMID:24734105

Qi, Ji; Tan, C K; Hashimi, Saeed M; Zulfiker, Abu Hasanat Md; Good, David; Wei, Ming Q

2014-01-01

176

One year in the life of Bufo punctatus: annual patterns of body temperature in a free-ranging desert anuran  

Science.gov (United States)

The Mojave Desert is characterized by hot dry summers and cold winters. The red-spotted toad ( Bufo ( Anaxyrus) punctatus) is the predominant anuran species; yet little is known of their thermal histories and strategies to avoid temperature extremes. We measured body temperature ( T b) in free-ranging adult toads across all four seasons of a year using implanted data loggers. There is marked individual variation in the temperatures experienced by these toads. As expected, toads generally escape extreme seasonal and diel temperature fluctuations. However, our data demonstrate a much wider estimated T b range than was previously assumed. Though often for short periods, red-spotted toads do experience T b as low as 3.1°C and as high as 39.1°C. All animals showed periods of prolonged thermal stability in cooler months and wider diel oscillations in warmer months. Red-spotted toad thermal history is likely a function of site choice; the exploitation of different refuges results in diverse thermal experiences. These data represent the most complete record of thermal experiences for a desert anuran and reveal greater extremes in body temperature than previously suggested.

Rausch, Candice M.; Starkweather, Peter L.; van Breukelen, Frank

2008-06-01

177

A cryptic heterogametic transition revealed by sex-linked DNA markers in Palearctic green toads.  

Science.gov (United States)

In sharp contrast to birds and mammals, most cold-blooded vertebrates have homomorphic (morphologically undifferentiated) sex chromosomes. This might result either from recurrent X-Y recombination (occurring e.g. during occasional events of sex reversal) or from frequent turnovers (during which sex-determining genes are overthrown by new autosomal mutations). Evidence for turnovers is indeed mounting in fish, but very few have so far been documented in amphibians, possibly because of practical difficulties in identifying sex chromosomes. Female heterogamety (ZW) has long been established in Bufo bufo, based on sex reversal and crossing experiments. Here, we investigate a sex-linked marker identified from a laboratory cross between Palearctic green toads (Bufo viridis subgroup). The F(1) offspring produced by a female Bufo balearicus and a male Bufo siculus were phenotypically sexed, displaying an even sex ratio. A sex-specific marker detected in highly reproducible AFLP genotypes was cloned. Sequencing revealed a noncoding, microsatellite-containing fragment. Reamplification and genotyping of families of this and a reciprocal cross showed B. siculus to be male heterogametic (XY) and suggested the same system for B. balearicus. Our results thus reveal a cryptic heterogametic transition within bufonid frogs and help explain patterns of hybrid fitness within the B. viridis subgroup. Turnovers of genetic sex-determination systems may be more frequent in amphibians than previously thought and thus contribute to the prevalence of homomorphic sex chromosomes in this group. PMID:21338434

Stöck, M; Croll, D; Dumas, Z; Biollay, S; Wang, J; Perrin, N

2011-05-01

178

Toad Abode: Creating a Home for a Backyard Toad  

Science.gov (United States)

In this activity about backyard habitats learners create a safe and toad-friendly environment near their own home. Since frogs and toads are too sensitive to touch, observing them in this make-shift home is a great idea for families. Have fun and be creative by using rocks and twigs to surround the abode; every toad needs a good home!

Aquariums, Association O.

2009-01-01

179

Effective number of breeding adults in Bufo bufo estimated from age-specific variation at minisatellite loci  

Science.gov (United States)

Estimates of the effective number of breeding adults were derived for three semi-isolated populations of the common toad Bufo bufo based on temporal (i.e. adult-progeny) variance in allele frequency for three highly polymorphic minisatellite loci. Estimates of spatial variance in allele frequency among populations and of age-specific measures of genetic variability are also described. Each population was characterized by a low effective adult breeding number (N(b)) based on a large age-specific variance in minisatellite allele frequency. Estimates of N(b) (range 21-46 for population means across three loci) were ??? 55-230-fold lower than estimates of total adult census size. The implications of low effective breeding numbers for long-term maintenance of genetic variability and population viability are discussed relative to the species' reproductive ecology, current land-use practices, and present and historical habitat modification and loss. The utility of indirect measures of population parameters such as N(b) and N(e) based on time-series data of minisatellite allele frequencies is discussed relative to similar measures estimated from commonly used genetic markers such as protein allozymes.

Scribner, K.T.; Arntzen, J.W.; Burke, T.

1997-01-01

180

Metacercariae of Clinostomum attenuatum in Ambystoma tigrinum mavortium, Bufo cognatus and Spea multiplicata from west Texas.  

Science.gov (United States)

Tissues from barred tiger salamanders (Ambystoma tigrinum mavortium), Great Plains toads (Bufo cognatus) and New Mexico spadefoots (Spea multiplicata) collected from 16 playa wetlands in Texas during 1999 and 2000 were examined by light microscopy. Digenean cysts were primarily distributed subcutaneously throughout the specimens and occasionally coelomic invasion was noted. The parasites within the cysts were 1.5-2 mm in diameter, with a thin (c. 10 microm wide) eosinophilic-staining tegument, two suckers (oral and ventral), posteriorly located primordial genitalia and paired digestive caeca. These digeneans were identified as the metacercariae of Clinostomum attenuatum. This is the first record of Clinostomum attenuatum in these amphibian species. PMID:15575998

Miller, D L; Bursey, C R; Gray, M J; Smith, L M

2004-12-01

 
 
 
 
181

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

Science.gov (United States)

Karyological and flow cytometric (FCM) analyses were performed on a group of 14 green toads of the Bufo viridis species from seven Eurasian populations. Both approaches gave concordant results concerning the DNA ploidy level. All the populations examined were represented exclusively by diploid or tetraploid specimens, except one, where triploids were found. Results evidenced an interpopulation variability in DNA content against the same ploidy level, as well as an unusually high number of triploids in a particular reproductive place. The origin of polyploidy and the presence and persistence of a high number of triploids in a particular population are discussed. PMID:12152793

Cavallo, D; De Vita, R; Eleuteri, P; Borkin, L; Ermechenko, V; Odiema, G; Balletto, E

2002-01-01

182

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

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

E Balletto

2010-01-01

183

Saturable urea transport pathway across the urinary bladder of Bufo viridis and salt acclimation.  

Science.gov (United States)

Urea fluxes across the urinary bladder of Bufo viridis were studied in vitro after modification of the mounting technique. The fluxes increased as a function of the bath urea concentration, saturating near 200 mmol/l. The apparent Km was 88 mmol/l in the bladders from tapwater-acclimated toads, and 107 mmol/l in toads acclimated to 500 mOsm NaCl. The Vmax which was 300 mumol.h-1.cm-2 at room temperature in bladders from tapwater acclimation, changed to more than 1500 mumol.h-1.cm-2 upon salt acclimation. It is suggested that urea movement across the urinary bladder of this species occurs by facilitated diffusion and that salt acclimation induces an increase in the density of this pathway, but not of its characteristics (Km). PMID:2804458

Shpun, S; Katz, U

1989-01-01

184

Temperature, hydric environment, and prior pathogen exposure alter the experimental severity of chytridiomycosis in boreal toads  

Science.gov (United States)

Prevalence of the pathogen Batrachochytrium dendrobatidis (Bd), implicated in amphibian population declines worldwide, is associated with habitat moisture and temperature, but few studies have varied these factors and measured the response to infection in amphibian hosts. We evaluated how varying humidity, contact with water, and temperature affected the manifestation of chytridiomycosis in boreal toads Anaxyrus (Bufo) boreas boreas and how prior exposure to Bd affects the likelihood of survival after re-exposure, such as may occur seasonally in long-lived species. Humidity did not affect survival or the degree of Bd infection, but a longer time in contact with water increased the likelihood of mortality. After exposure to ~106 Bd zoospores, all toads in continuous contact with water died within 30 d. Moreover, Bd-exposed toads that were disease-free after 64 d under dry conditions, developed lethal chytridiomycosis within 70 d of transfer to wet conditions. Toads in unheated aquaria (mean = 15°C) survived less than 48 d, while those in moderately heated aquaria (mean = 18°C) survived 115 d post-exposure and exhibited behavioral fever, selecting warmer sites across a temperature gradient. We also found benefits of prior Bd infection: previously exposed toads survived 3 times longer than Bd-naïve toads after re-exposure to 106 zoospores (89 vs. 30 d), but only when dry microenvironments were available. This study illustrates how the outcome of Bd infection in boreal toads is environmentally dependent: when continuously wet, high reinfection rates may overwhelm defenses, but periodic drying, moderate warming, and previous infection may allow infected toads to extend their survival.

Murphy, Peter J.; St-Hilaire, Sophie; Corn, Paul Stephen

2011-01-01

185

Salida de campo a Laguna de Duero (Valladolid) el 7 de enero de 1952  

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Field trip to Laguna de Duero (Valladolid) the 7th of January of 1952, of which there were noted observations about the following amphibians: Epidalea calamita (Natterjack Toad, refered as Bufo calamita by the author), Pelobates cultripes (Western Spadefoot) and Pelophylax esculentus (Edible Frog, refered as Rana sculenta by the author), the following mammals: Arvicola sapidus (Southern Water Vole) and "Pytimis" (as refered by the author, being possibly the current genus Microtus), and the fo...

Valverde Go?mez, Jose? Antonio

2008-01-01

186

Salida de campo a la laguna de La Nava (Fuentes de Nava, Palencia) el 27 y 28 de julio de 1952  

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Field trip to the lake of La Nava, at Fuentes de Nava, travelling also through Grijota and Villamartín de Campos, at the province of Palencia, the 27th and 28th of July of 1952, of which there were noted observations about the following amphibians: Epidalea calamita (Natterjack Toad, refered as Bufo calamita by the author), Pelobates cultripes (Western Spadefoot), Pelophylax esculentus (Edible Frog, refered as Rana sculenta or R.esculenta ridibunda by the author) and Pleurodeles waltl (Iber...

Valverde Go?mez, Jose? Antonio

2008-01-01

187

Lack of bufadienolides in the skin secretion of red bellied toads, Melanophryniscus spp. (Anura, Bufonidae), from Uruguay.  

Science.gov (United States)

The South-American red bellied toads (Melanophryniscus spp.) belonging to the Bufonidae family contain toxic alkaloids in their skin, predominantly of the pumiliotoxin group. Whole animal methanolic extracts of individual specimens of three species (Melanophryniscus atroluteus, M. devincenzii, and M. montevidensis) were analyzed for the presence of toad specific bufadienolides and indolalkylamines (serotonin derivatives) by HPLC-electrospray (ESI)-MS-TOF. No bufadienolides, but few bufotenines, mainly dehydrobufotenine, were detected in the extracts in variable amounts. The concentration of the dehydrobufotenine in the extracts seems to be species specific. Whereas M. atroluteus and M. montevidensis contain very low or trace amounts, M. devincenzii specimens exhibit high concentrations of this indolalkylamine. In comparison, analysis of extracts from Bufo arenarum (Uruguay) and from B. bufo (Germany) confirmed the presence of bufadienolides as well as of bufotenine derivatives. Tadpoles of both species exhibited a different pattern: extracts from B. arenarum tadpoles contained only dehydrobufotenine, but those from B. bufo tadpoles bufotoxin and two alkylamines. Melanophryniscus toads appear not to be able to compensate the high variability of toxic skin alkaloids by producing defensive bufadienolides. PMID:17208052

Mebs, Dietrich; Wagner, Moritz G; Pogoda, Werner; Maneyro, Raul; Kwet, Axel; Kauert, Gerold

2007-01-01

188

Role of environmental pollutants on immune functions, parasitic infections and limb malformations in marine toads and whistling frogs from Bermuda.  

Science.gov (United States)

Soil, water, and amphibian tissues collected between 1995 and 1999 from 15 study sites in Bermuda were analysed for pesticides and heavy metals. The most abundant pesticide residue in soil was p,p'-dichlorodiphenyldichloroethylene (DDE) which was found at all sites in concentrations ranging from 0.003 to 4.023 p.p.m. No pesticide residues were found in water. DDE was also recovered from the livers and fat bodies of marine toads (Bufo marinus) and whistling frogs (Eleutherodactylus johnstonei). Analyses of food sources consumed by these anuran species revealed residue levels of p, p'-DDE ranging from 0.05 to 0.217 p.p.m. Other soil residues included dichlorodiphenyltrichloroethane (DDT) at eight study sites, Dicofol(kelthane) at eight sites, dieldrin at five sites, and polychlorinated biphenyls (PCBs) as Arochlor 1254 and Arochlor 1260 at seven sites. Analyses of toad livers revealed significant concentrations of cadmium, chromium, copper and zinc. Livers of Bermuda toads exhibited altered hepatocytic morphology and an increased number of melanomacrophages and possible granulomas, while spleens showed a marked decrease in white pulp. Spleen cells from Bufo marinus collected at one site having high levels of cadmium exhibited a decreased B cell response to lipopolysaccharide. The incidence of trematode infection in Bufo marinus increased from 53.8% in 1995 to 90% in 1999. Deformity rates in the limbs of subadult and adult toads ranged between 15 and 25%. Examination of 1,995 newly-metamorphosed toads revealed deformity rates as high as 47%. The current comprehensive study suggests that environmental pollutants may account for immunosuppression, increased susceptibility to infections, limb malformations and possible decline in amphibian populations from Bermuda. PMID:12745335

Linzey, Donald; Burroughs, Joy; Hudson, Lisa; Marini, Michele; Robertson, John; Bacon, Jamie; Nagarkatti, Mitzi; Nagarkatti, Prakash

2003-06-01

189

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

Scientific Electronic Library Online (English)

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

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

190

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

Scientific Electronic Library Online (English)

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

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

1787-17-01

191

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

Directory of Open Access Journals (Sweden)

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.

Luciana Sonne

2008-09-01

192

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

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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.

Tonglei Yu

2012-02-01

193

Prey-Catching Behaviour in Mudskippers and Toads: A Comparative Analysis  

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Full Text Available The invasion of land by a diverse group of fishlike amphibians during the Middle-Late Devonian was a key event in the history of life. It is obvious that the evolutionary transition from an aquatic to a terrestrial habitat was associated with physiological adaptations such as novel feeding strategies that can not be elucidated with fossils alone. Here we show that two extant vertebrate species, an amphibious fish (the Atlantic mudskipper Periophthalmus barbarus L., and the common toad (Bufo bufo L., which both feed on earthworms, have evolved the same modes of prey recognition. In double-choice experiments, both the fish and the tetrapod tried to capture a moving black bar in worm configuration; a vertical (anti-worm stimulus did not elicit such a response. This finding sheds light on events that may have occurred in semi-aquatic habitats over 370 million years ago.

U. Kutschera

2008-01-01

194

Electrophoretic patterns of proteins in the secretion of Parotoid gland and its extract in Bufo melanostictus (Schneider  

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Full Text Available The present study was carried out to analyze qualitatively the Electrophoretic patterns of proteins in Parotoid gland extract and its secretion in terrestrial toad Bufo melanostictus (Indian toad. The patterns indicated that the gland extraction has higher number of protein bands compared to the gland secretion. The patterns of protein bands observed in the parotoid gland extraction of B. melanostictus using Sodium Dodecyl Sulphate Poly Acryl amide Gel Electrophoresis (SDS-PAGE indicated a distinct pattern of four protein bands and some additional bands, with poor resolution, where as two protein bands in the parotoid gland secretion. The electrophoretogram revealed that both the patterns of parotoid gland extract and its secretion showed homology in protein bands with minor variations.

Raju Neerati

2013-08-01

195

Changes to the generic names of extinct east European species described as Bufo belogoricus Ratnikov, 1993, Bufo planus Ratnikov, 1993 and Bufo albus Ratnikov, 1993  

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Full Text Available The generic assignment of three fossil forms described as Bufo belogoricus Ratnikov, 1993, Bufo planus Ratnikov, 1993 and Bufo albus Ratnikov, 1993 is discussed. The author justifies why their original generic names should not be changed to Pseudepidalea, as recently proposed, but should be maintained until more convincing evidence is discovered.Se discute la atribución genérica de tres formas fósiles descritas como Bufo belogoricus Ratnikov, 1993, Bufo planus Ratnikov, 1993, y Bufo albus Ratnikov, 1993. El autor justifica las razones por las cuales las adscripciones genéricas originales no deberían cambiarse a Pseudepidalea, como recientemente se ha propuesto, sino mantenerse hasta que se descubra nueva evidencia más convincente.

Ratnikov, V. Yu

2013-06-01

196

Distribution and pathogenicity of Batrachochytrium dendrobatidis in boreal toads from the grand teton area of western wyoming  

Science.gov (United States)

The pathogen Batrachochytrium dendrobatidis (Bd), which causes the skin disease chytridiomycosis, has been linked to amphibian population declines and extinctions worldwide. Bd has been implicated in recent declines of boreal toads, Bufo boreas boreas, in Colorado but populations of boreal toads in western Wyoming have high prevalence of Bd without suffering catastrophic mortality. In a field and laboratory study, we investigated the prevalence of Bd in boreal toads from the Grand Teton ecosystem (GRTE) in Wyoming and tested the pathogenicity of Bd to these toads in several environments. The pathogen was present in breeding adults at all 10 sites sampled, with a mean prevalence of 67%. In an experiment with juvenile toadlets housed individually in wet environments, 106 zoospores of Bd isolated from GRTE caused lethal disease in all Wyoming and Colorado animals within 35 days. Survival time was longer in toadlets from Wyoming than Colorado and in toadlets spending more time in dry sites. In a second trial involving Colorado toadlets exposed to 35% fewer Bd zoospores, infection peaked and subsided over 68 days with no lethal chytridiomycosis in any treatment. However, compared with drier aquaria with dry refuges, Bd infection intensity was 41% higher in more humid aquaria and 81% higher without dry refuges available. Our findings suggest that although widely infected in nature, Wyoming toads may escape chytridiomycosis due to a slight advantage in innate resistance or because their native habitat hinders Bd growth or provides more opportunities to reduce pathogen loads behaviorally than in Colorado. ?? 2009 International Association for Ecology and Health.

Murphy, P.J.; St-Hilaire, S.; Bruer, S.; Corn, P.S.; Peterson, C.R.

2009-01-01

197

Uma nova hemogregarina no sangue de Bufo crucifer wied, 1821 do Brasil A new hemogregarine in the blood of Bufo crucifer wied, 1821 from Brazil  

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Full Text Available A ocorrência de hemagregarinas no sangue dos sapos que examinamos (Bufo crucifer, B. marinus e Melanophryniscus moreirae revelou-se extremamente rara; apenas um exemplar de B. crucifer procedente de Manguinhos (Rio de Janeiro, Guanabara apresentou-se parasitado. As formas sanguíneas encontradas eram intra-eritrocitárias, medindo em média 10,8/ 3,6µ; não as identificamos como trofozoítos ou gametócitos e discutimos este fato. As hemácias parasitadas tinham dimensões normais, porém podiam ter o núcleo deslocado. Supomos ser esta a primeira referência a hemogregarinas neste hospedeiro. Não encontramos identidade entre as formas que descrevemos e aquelas referidas em outras espécies de sapos; fornecemos uma lista das hemogregarinas achadas nestes hospedeiros. Denominamos provisoriamente os parasitos que encontramos Haemogregarina "sensu lato", até que novos dados sobre seu ciclo evolutivo sejam conhecidos.The occurrence of hemogregarines in the blood of Brazilian toads that we have examined (Bufo crucifer, B. Marinus and Melanophryniscus moreirae has displayed very scarce; only one specimen of B. crucifer from Manguinhos (Rio de Janeiro, Guanabara was infected. The blood forms that we found were intraerythrocytic, averaging 10,8 by 3,6µ; we did not differenciate them as thophozoites or as gametocytes and we discuss this fact. The infected erythrocytes were not hypertrophied and their nucleus was normal and sometimes displaced. We think that it is the first reference to hemogregarines in this host. We did not evidence identity among the forms that we described and those reported in other species of toads; we give a list of hemogregarines found in those hosts. We provisorily named the parasites that we found Haemogregarina "sensu lato", until new data about their life cycle become known.

Maria Auxiliadora de Sousa

1974-01-01

198

Uma nova hemogregarina no sangue de Bufo crucifer wied, 1821 do Brasil / A new hemogregarine in the blood of Bufo crucifer wied, 1821 from Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A ocorrência de hemagregarinas no sangue dos sapos que examinamos (Bufo crucifer, B. marinus e Melanophryniscus moreirae) revelou-se extremamente rara; apenas um exemplar de B. crucifer procedente de Manguinhos (Rio de Janeiro, Guanabara) apresentou-se parasitado. As formas sanguíneas encontradas er [...] am intra-eritrocitárias, medindo em média 10,8/ 3,6µ; não as identificamos como trofozoítos ou gametócitos e discutimos este fato. As hemácias parasitadas tinham dimensões normais, porém podiam ter o núcleo deslocado. Supomos ser esta a primeira referência a hemogregarinas neste hospedeiro. Não encontramos identidade entre as formas que descrevemos e aquelas referidas em outras espécies de sapos; fornecemos uma lista das hemogregarinas achadas nestes hospedeiros. Denominamos provisoriamente os parasitos que encontramos Haemogregarina "sensu lato", até que novos dados sobre seu ciclo evolutivo sejam conhecidos. Abstract in english The occurrence of hemogregarines in the blood of Brazilian toads that we have examined (Bufo crucifer, B. Marinus and Melanophryniscus moreirae) has displayed very scarce; only one specimen of B. crucifer from Manguinhos (Rio de Janeiro, Guanabara) was infected. The blood forms that we found were in [...] traerythrocytic, averaging 10,8 by 3,6µ; we did not differenciate them as thophozoites or as gametocytes and we discuss this fact. The infected erythrocytes were not hypertrophied and their nucleus was normal and sometimes displaced. We think that it is the first reference to hemogregarines in this host. We did not evidence identity among the forms that we described and those reported in other species of toads; we give a list of hemogregarines found in those hosts. We provisorily named the parasites that we found Haemogregarina "sensu lato", until new data about their life cycle become known.

Maria Auxiliadora de, Sousa; Attilio, Borriello Filho.

199

C23 steroids from the venom of Bufo bufo gargarizans.  

Science.gov (United States)

Five new C23 steroids (1-5) together with five known bufadienolides (6-10) were isolated from the venom of Bufo bufo gargarizans (ChanSu in Chinese). The structures of the new steroids were elucidated by extensive spectroscopic methods in combination with X-ray diffraction analysis. Among these C23 steroids, only compound 3 showed cytotoxicities against HepG2 and A549 cancer cells, with respective IC50 values of 26.8 ± 8.3 and 45.6 ± 2.5 ?M. In contrast, the bufadienolides (7-10) displayed potent inhibitory activities against these cancer cells, with respective IC50 values in the ranges 0.5-5.5 and 0.6-6.5 ?M, but relatively less cytotoxicity on normal mouse spleen cells. In addition, the Na(+)/K(+)-ATPase inhibitory activities of 2, 5, and 7 revealed that the lactone moiety of a bufadienolide was important for the inhibitory activity. PMID:24050254

Tian, Hai-Yan; Luo, Shi-Lin; Liu, Jun-Shan; Wang, Lei; Wang, Ying; Zhang, Dong-Mei; Zhang, Xiao-Qi; Jiang, Ren-Wang; Ye, Wen-Cai

2013-10-25

200

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

Scientific Electronic Library Online (English)

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

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

 
 
 
 
201

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

Scientific Electronic Library Online (English)

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

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

2000-05-01

202

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

International Nuclear Information System (INIS)

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.

203

Haematological changes in Bufo maculatus treated with sublethal concentrations of Cadmium  

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

Alex Ajeh Enuneku

2011-05-01

204

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

Science.gov (United States)

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. PMID:20828901

Dorchin, A; Shanas, U

2010-12-01

205

Miniaturized bioaffinity assessment coupled to mass spectrometry for guided purification of bioactives from toad and cone snail.  

Science.gov (United States)

A nano-flow high-resolution screening platform, featuring a parallel chip-based microfluidic bioassay and mass spectrometry coupled to nano-liquid chromatography, was applied to screen animal venoms for nicotinic acetylcholine receptor like (nAChR) affinity by using the acetylcholine binding protein, a mimic of the nAChR. The potential of this microfluidic platform is demonstrated by profiling the Conus textile venom proteome, consisting of over 1,000 peptides. Within one analysis (Bufo alvarius and Bufo marinus). Bioactives from the toad samples were subsequently isolated by MS-guided fractionation. The fractions analyzed by NMR and a radioligand binding assay with ?7-nAChR confirmed the identity and bioactivity of several new ligands. PMID:24833338

Heus, Ferry; Otvos, Reka A; Aspers, Ruud L E G; van Elk, Rene; Halff, Jenny I; Ehlers, Andreas W; Dutertre, Sébastien; Lewis, Richard J; Wijmenga, Sybren; Smit, August B; Niessen, Wilfried M A; Kool, Jeroen

2014-01-01

206

A suspected parasite spill-back of two novel Myxidium spp. (Myxosporea) causing disease in Australian endemic frogs found in the invasive Cane toad.  

Science.gov (United States)

Infectious diseases are contributing to the decline of endangered amphibians. We identified myxosporean parasites, Myxidium spp. (Myxosporea: Myxozoa), in the brain and liver of declining native frogs, the Green and Golden Bell frog (Litoria aurea) and the Southern Bell frog (Litoria raniformis). We unequivocally identified two Myxidium spp. (both generalist) affecting Australian native frogs and the invasive Cane toad (Bufo marinus, syn. Rhinella marina) and demonstrated their association with disease. Our study tested the identity of Myxidium spp. within native frogs and the invasive Cane toad (brought to Australia in 1935, via Hawaii) to resolve the question whether the Cane toad introduced them to Australia. We showed that the Australian brain and liver Myxidium spp. differed 9%, 7%, 34% and 37% at the small subunit rDNA, large subunit rDNA, internal transcribed spacers 1 and 2, but were distinct from Myxidium cf. immersum from Cane toads in Brazil. Plotting minimum within-group distance against maximum intra-group distance confirmed their independent evolutionary trajectory. Transmission electron microscopy revealed that the brain stages localize inside axons. Myxospores were morphologically indistinguishable, therefore genetic characterisation was necessary to recognise these cryptic species. It is unlikely that the Cane toad brought the myxosporean parasites to Australia, because the parasites were not found in 261 Hawaiian Cane toads. Instead, these data support the enemy-release hypothesis predicting that not all parasites are translocated with their hosts and suggest that the Cane toad may have played an important spill-back role in their emergence and facilitated their dissemination. This work emphasizes the importance of accurate species identification of pathogens relevant to wildlife management and disease control. In our case it is paving the road for the spill-back role of the Cane toad and the parasite emergence. PMID:21541340

Hartigan, Ashlie; Fiala, Ivan; Dyková, Iva; Jirk?, Miloslav; Okimoto, Ben; Rose, Karrie; Phalen, David N; Šlapeta, Jan

2011-01-01

207

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

DEFF Research Database (Denmark)

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

Thomsen, Steffen Nyegaard; Wang, Tobias

208

Purification of PRL receptors from toad kidney: Comparisons with rabbit mammary PRL receptors  

International Nuclear Information System (INIS)

The binding characteristics of the prolactin (PRL) receptors present in toad (Bufo marinus) kidneys were investigated and compared to those of PRL receptors present in rabbit mammary glands. The molecular characteristics of the Triton X-100 solubilized renal and mammary PRL receptors were assessed by gel filtration and by migration analysis on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) after affinity labeling of the binding sites with 125I-human growth hormone. Similar results were obtained for both receptors. Partial purification of the toad PRL receptor could be achieved by affinity chromatography. The molecular weight of this purified receptor could be determined by analysis of SDS-PAGE. With the use of a polyclonal antiserum raised against a purified preparation of rabbit mammary PRL receptor, one or several antigenic epitope(s) could be identified on the core of the toad renal PRL receptor. In conclusion, although the structure and the biological role(s) of PRL have substantially changed during evolution, the receptor for this hormone has retained many of its structural features as could be assessed between an amphibian and a mammalian species on functionally different target tissues

209

Elevated plasma osmotic concentration stimulates water absorption response in a toad.  

Science.gov (United States)

The water-seeking behavior (WR) of toads (Bufo viridis) was investigated. Fully hydrated toads that are allowed free choice of wet or dry filter paper voluntarily and spontaneously select to sit on water-soaked paper at a regular frequency during trials. Dehydration of bladder-emptied toads by 14% elicits WR in all animals. Injection of aldosterone or angiotensin-I reduced the dehydration threshold to 7% weight loss. WR frequency increased when plasma osmolality was elevated by injection of NaCl or other solutes (both ionic and non-ionic). Only urea, to which cell membranes are highly permeable, was the exception that did not produce this response. The increase in WR frequency induced by elevated plasma osmolality was augmented by injection of aldosterone or angiotensin-I. In vivo water uptake, measured in a water bath, was increased by an NaCl or oxytocin injection, but not by aldosterone. It is concluded that elevated plasma osmolality induces an increase in WR frequency that is separate and prior to the water uptake process. Different hormones are involved in each step. PMID:10404645

Hoffman, J; Katz, U

1999-07-01

210

Two new endemic genera and a new species of toad (Anura: Bufonidae from the Western Ghats of India  

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Full Text Available Abstract Background Bufonidae are a large family of toads with a subcosmopolitan distribution. Recent molecular phylogenetic analyses have revealed a radiation of toads (Adenominae with distinct adult and larval ecomorphs on the Southern parts of the Indian subcontinent. The Indian torrential species "Ansonia" ornata has a basal position in this clade and does not group with South-East Asian Ansonia. Additionally, the nested position of "Bufo" koynayensis and an undescribed sister species, and their distinct ecologies including a non-typical egg-laying strategy within bufonids, support the recognition of a second distinct genus. In this paper we describe two new genera and one new species from the Adenominae clade. Findings Ansonia ornata Günther, 1876 "1875" is transferred to Ghatophryne gen. nov., a genus of torrentially adapted toads that are endemic to the Western Ghats of India. On the basis of close morphological resemblance and distribution, Ansonia rubigina Pillai and Pattabiraman, 1981 is provisionally transferred to this new genus. The Western Ghats endemic toad Bufo koynayensis Soman, 1963 is transferred to a new genus Xanthophryne gen. nov. Based on molecular and morphological evidence, we additionally describe a new species, Xanthophryne tigerinus sp. nov., from Amboli in the Western Ghats. Conclusion The descriptions and subsequent taxonomic changes we propose result in three genera of bufonids recognised as being endemic to the Western Ghats (Ghatophryne gen. nov., Xanthophryne gen. nov. and Pedostibes, and one to Sri Lanka (Adenomus. The spatial distribution, and arrangement of these lineages at the base of Adenominae diversification, reflects their Early Neogene isolation in the Western Ghats-Sri Lanka hotspot.

Loader Simon P

2009-12-01

211

Berberine-induced pigment dispersion in Bufo melanostictus melanophores by stimulation of beta-2 adrenergic receptors.  

Science.gov (United States)

Reduced production of melanin by decreased or the absence of melanocytes leads to various hypopigmentation disorders, and the development of melanogenetic agents for photoprotection and hypopigmentation disorders is one of the top priority areas of research. Hence, the present study was carried out to elucidate the ability of berberine, a principal active ingredient present in the roots of the herb Berberis vulgaris to stimulate pigment dispersion in the isolated skin melanophores of the toad Bufo melanostictus. In the present study, mean melanophore size index of the isolated skin melanophores of B. melanostictus was assayed after treating with various concentrations of berberine. A marked melanin dispersion response leading to skin darkening was observed in the isolated melanophores of toad in response to berberine, which was found to be mediated through beta-2 adrenergic receptors. The physiologically significant dose-related melanin dispersion effects of berberine per se were found to be completely abolished by propranolol, which is a specific beta-2 adrenergic receptor blocker. These per se melanin dispersal effects were also found to be markedly potentiated by isoprenaline, which is a specific beta-adrenoceptor agonist. The results indicate that berberine causes a tremendous, dose-dependent, physiologically significant pigment dispersing in the isolated skin melanophores of B. melanostictus. PMID:24099619

Ali, Sharique A; Naaz, Ishrat; Choudhary, Ram Kumar

2014-02-01

212

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

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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.

NWORAH DC, OLORUNFEMI OJ

2011-12-01

213

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

Scientific Electronic Library Online (English)

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

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

1956-10-01

214

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

Scientific Electronic Library Online (English)

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

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

215

Ocorrência de Amblyomma fuscum Neumann, 1899 e Amblyomma humerale Koch, 1844 (Acari: Ixodidae) em Bufo arenalis no estado de São Paulo, Brasil / Occurence of Amblyomma fuscum Neumann, 1899 and Amblyomma humerale Koch, 1844 (Acari: Ixodidae) in Bufo arenalis in the state of São Paulo, Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo deste trabalho é relatar a ocorrência do parasitismo monoespecífico de A. fuscum NEUMANN, 1899 e A. humerale KOCH, 1844 em sapos (Bufo arenalis) no Município de Rosana, Estado de São Paulo, Brasil. Este relato caracteriza um novo hospedeiro e uma nova localização geográfica para estas dua [...] s espécies de carrapatos. Abstract in english The objective of this work is to describe the occurence of the monoespecific parasitism of A. fuscum NEUMANN, 1899 and A. humerale KOCH, 1844 in toads (Bufo arenalis) from the County of Rosana, State of São Paulo, Brazil. This is the description of a new host and new geographic site for those two sp [...] ecies.

Afonso Lodovico, Sinkoc; João Guilherme Werner, Brum.

216

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

Scientific Electronic Library Online (English)

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

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

1282-12-01

217

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

Scientific Electronic Library Online (English)

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

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

218

Nematode larvae (order Spirurida) in gastric tissues of Australian anurans: a comparison between the introduced cane toad and sympatric native frogs.  

Science.gov (United States)

The outcomes of host-parasite interactions depend heavily on the host's immune response, which, in turn, is governed by previous interactions between the host and parasite, both over the host's life time and over evolutionary time. In the case of species introductions, such as the cane toad (Bufo marinus) to Australia, parasites that are benign to native species of the introduced range may present a major challenge to the introduced species. Stomachs of introduced cane toads and seven species of sympatric native frogs were examined for parasites, and their pathology and biology were compared. Cane toads were host to eight species of third-stage spirurid larvae, six of which also occurred in the stomach wall of four native frog species. In general, encysted nematode larvae attained higher prevalence and species richness in introduced cane toads than in sympatric native frogs. This trend was largely explained by differences in body sizes: larger anurans were more likely to possess infections, and cane toads are inherently larger than native frogs. Encysted larvae in cane toad stomachs provoked a marked pathologic response. All larvae (physalopterine and Physocephalus spp.) were surrounded by concentric layers of dense, fibrous tissue, with considerable cellular infiltration characterized by lymphocytes and polymorphs. Many cysts were invaded by cells and exudate, which, in more advanced cases, became calcified. Some larvae appeared viable; most were in various stages of destruction, and some smaller Physocephalus spp. were mummified. Conversely, pathologic response observed in native frogs was minimal, with little fibrotic reaction surrounding the cysts, and no cellular infiltration. Presumably, the contrast in pathology between introduced and native hosts reflects the long evolutionary association between these nematode larvae and native frogs, whereas the recent exposure of introduced toads to these helminths provokes a severe reaction. PMID:20966264

Kelehear, Crystal; Jones, Hugh I

2010-10-01

219

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

Science.gov (United States)

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.

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

2008-01-01

220

Variación estacional en la proporción relativa de los estadios de la oogénesis en Bufo arenarum (Anura: Bufonidae  

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Full Text Available The Anova repeated measure design was used to compare the percentage of oocytes in female toads (Bufo arenarum at stages 1 to 5 and at different physiological ovary periods (or phases: production, before ovulation, after ovulation. Individual comparisons among stages and between phases have been made with the minimum significant difference method at 0.05 probability level. The statistical analysis at percentage of oocytes showed that: a Stages 1 and 2 have few variation. They are the permanent oocytes group. b Stage 3 (late vitelogenesis oocytes are absent previous to the breeding season. Their rate increases in summer and decreases in autumn. The development of oocytes 3 take place afterwards the ovulation. c Stage 4 increases in autumn and disappears in late winter. d Stage 5 sets up as the 18% of the ovulated oocytes. e. Stages 3, 4 and 5 are renewed every year; they are temporary ovarian oocytes.

Echeverría, Dinorah D.

1994-01-01

 
 
 
 
221

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

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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.

Inoue Eiji

2014-03-01

222

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

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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.

Lo Brutto Sabrina

2008-02-01

223

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

International Nuclear Information System (INIS)

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

224

Lectin binding pattern and band 3 localization in toad skin epithelium and the effect of salt acclimation.  

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Seven lectins were employed to localize glycoconjugates in the skin of a toad (Bufo viridis). Each of the lectins exhibited a particular, specific and selective binding pattern. Peanut lectin (PNA) and WGA bound to mitochondria-rich (MR) cells, but WGA bound also abundantly, in the dermis. Band 3-like protein, as indicated by the reaction with polyclonal anti band 3 antibody, was localized exclusively in MR cells. Ionic acclimation (200 mmol/L NaCl, or 50 mmol/L KCl) affected profoundly the binding pattern of the lectins. High NaCl acclimation resulted also in diminishing anti band 3 antibody binding, whereas in skins of KCl-acclimated toads the staining remained similar to the control. The binding of WGA but not PNA, corresponded with the same cells that stained with anti band 3 antibody. PNA in concentration of > 10 micrograms/mL reduced reversibly, both the resting and activated Cl- conductance by 25-30%. Based on differential binding of band 3, WGA and PNA, these observations provide conclusive verification of the presence of at least two populations of MR cells in the toad skin epithelium. It is suggested that the PNA positive MR cells may correspond to a beta-type MR cell. The information can be used to study molecular mechanisms that are involved in ionic acclimation. PMID:9351193

Katz, U; Zaccone, G; Fasulo, S; Mauceri, A; Gabbay, S

1997-05-01

225

Chloride conductance across toad skin: effects of ionic acclimations and cyclic AMP and relationship to mitochondria-rich cell density.  

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The anionic conductance across toad (Bufo viridis) skin was studied using the voltage-clamp technique following long-term (more than 10 days) acclimation to NaCl and KCl solutions. The non-specific baseline conductance was approximately 0.6 mS cm(-)(2) and was similar in skins from all acclimation conditions. The voltage-activated Cl(-) conductance (G(Cl)) was maximal in skins from distilled-water- and KCl-acclimated toads (>3 mS cm(-)(2)) and was greatly reduced following acclimation to NaCl solutions. Cyclic AMP (EC(50)=13 micromol l(-)(1)) and isobutylmethyl xanthine (IBMX) (EC(50)=69 micromol l(-)(1)) exerted different effects on the activated conductance. IBMX only sensitized the activated conductance, whereas cyclic AMP (CPTcAMP) at high concentrations induced an increase in anionic conductance that was insensitive to electrical potential. Furthermore, external Cl(-) was not required for the stimulatory effect of cyclic AMP, and the conductive pathway had low selectivity. The effects of the two agonists were reversible and depended on the acclimation conditions. Following electrical measurements, the skin of the toads was removed and stained with silver to measure mitochondria-rich cell density (D(mrc)). There was no correlation between D(mrc) and Cl(-) conductance in the present study. PMID:10851120

Rozman, A; Gabbay, S; Katz, U

2000-07-01

226

Isolation of morphine from toad skin.  

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A nonpeptide opioid was found in toad skin and purified to homogeneity by using HPLC with electrochemical detection. A nonpeptide opioid also was detected in bovine brain and adrenals as well as rabbit and rat skin, by reversed-phase HPLC following Sephadex G-15 column chromatography. The material in toad skin was identical to morphine by immunological, pharmacological, and physical chemical criteria.

Oka, K.; Kantrowitz, J. D.; Spector, S.

1985-01-01

227

[Cloning and bioinformatic analysis of TAGLN2 cDNA of Bufo japonicus formosus].  

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To study the bioactive polypeptides included in Bufo skin and its secretions the plasmid skin cDNA library of adult Japanese toad Bufo japonicus formosus was prepared. The pSD64TR has been used as the vector and the cloning sites are Xho I and EcoR I. To screen cDNAs encoding bioactive components, the plasmid cDNA library was transformed into E. coli DH5 competent cells, and positive colonies were screened by colony PCR (polymerase chain reaction). The suspension of a single colony in LB medium was used as the template, SP6 (the upstream primer of the plasmid cDNA library) and a primer with Xho I site and polyT were used as the primers. As the result, 465 positive colonies out of 1 344 were obtained and their plasmid were collected and sequenced. By homologous analysis, it was found that one of the cDNAs encoding a peptide with high homolog with transgelin-2, which was registered in GenBank (accession number: JX197456), and it was indicated as a partial cDNA sequence with a deletion at the 5' end. The transcript is 997 bp consisting of 31 bp 5', 618 bp 3' untranslated region (UTR) and an open reading frame (ORF) of 348 bp encoding a polypeptide of 115 amino acids. In the putative protein product, there is a calponin homology domain, two cysteine residues for a disulfide bond and three a-helix domains, and five potential phosphorylation sites. The homologous analysis indicates 90% similarity with Xenopus (Silurana) tropicalis and 89% with Xenopus laevis, and 71%-85% with other species. PMID:23672022

Zhuge, Hui; Yuan, Jin-Qiang; Zhang, Shu-Fang; Yang, Xian-Yu

2013-02-01

228

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

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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.

Rengel, Dora

1994-01-01

229

Diseases of frogs and toads  

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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).

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

2005-01-01

230

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

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Full Text Available SciELO Brazil | Language: English Abstract in english 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

L.H., Gargaglioni; L.G.S., Branco.

231

Identification and detection of the isolated sinus venosus from the Asian toad.  

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The pacemaker activity of mammalian sinoatrial node (SAN) of the heart plays a fundamental role in the integration of vital functions. Studying factors such as drugs that influence pacemaker activity of SAN has its significance. In this study, we isolated sinus venosus, SAN from toads (Bufo gargarizans), and analysed its electronic signal, histological characteristics and the influence of acetylcholine (ACh) and ivabradine on its pacemaker activity using PowerLab® and Chart® 5.0 software. We found that when isolated sinus venosus was treated with ACh, its histological distribution was disorganized and inter-beat (RR) interval was also broadened. The high frequency normalized unit (HFnu) and Poincaré plot of heart rate variability (HRV) of the isolated sinus venosus was also altered upon ACh treatment in a time-dependent and dose-dependent manner. When treated with ivabradine, these parameters of HRV such as square root of the mean of the squared differences between adjacent NN intervals (RMSSD) and HFnu were in the upward tendency, but low frequency normalized unit and low frequency/high frequency were in the opposite tendency. Taken together, we have developed a new model for studying the influences of drugs on autorhythmicity using isolated sinus venosus of the toad. With this model, we showed that ACh and ivabradine may affect the pacemaker activity by stimulating muscarinic receptor or inhibiting If current, respectively. PMID:23348247

Deng, Xin; Guan, Chao; Wang, Yang; Zhang, Bing; Li, Sen; Sun, Guiyuan; Hao, Liying; Li, Gensong

2013-12-01

232

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

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

2014-01-01

233

An evaluation of weather and disease as causes of decline in two populations of boreal toads  

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Two populations of boreal toads (Bufo boreas) experienced drastic declines in abundance in the late 1990s. Evidence supported the hypothesis of disease (the chytrid fungus, Batrachochytrium dendrobatidis) as the cause of these declines, but other hypotheses had not been evaluated. We used an 11-year capture-recapture data set to evaluate weather and disease as causes of these declines. We developed sets of mathematical models that reflected hypothesized relationships between several weather variables and annual survival rates of adult males in these populations. In addition, models that reflected the possibility that the declines were caused by an introduced fungus were developed. All models were fit to the data and were evaluated using a model selection criterion (QAICc). Our analysis provided strong support for the hypothesis of an introduced fungus and little support for the hypothesis that weather conditions caused the declines. Our results also suggest a strong, negative 'marking effect' on survival rates of boreal toads. Model-averaged estimates of survival rate are presented.

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

2005-01-01

234

Active urea transport in toad skin is coupled to H+ gradients.  

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Active transport of urea exists inwardly through the skin of the toad Bufo viridis and is enhanced by adapting the toads to hypertonic saline solutions. In this paper, we report our studies on the energy coupling of this active transport system. We have shown previously that this system is independent of sodium transport. We thus studied the possibility of coupling to proton transport by studying the following: 1) the effect of acidifying the epithelium by means of CO2 and protonophores, 2) the effect of alkalinizing the epithelium with the anion-exchange inhibitor 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS) and by removal of chloride from the serosal medium, 3) the effect of inhibiting the proton-translocating ATPase of the skin, 4) dependence on mucosal pH. We found that 1) acidification of the epithelium by means of 5% CO2 and the protonophores carbonyl cyanide m-chlorophenylhydrazone (CCCP) and nigericin inhibited urea influx; 2) alkalinization of the epithelium by means of the disulfonic stilbene DIDS and by removal of serosal chloride increased urea influx; 3) inhibition of the proton-translocating ATPase of the skin by means of 1,3-dicyclohexylcarbodiimide (DCCD), N-ethylmaleimide (NEM), and sodium orthovanadate inhibited urea transport; 4) urea influx was unaffected by alkalinizing the external medium to 8.5 or by acidifying to 6.5; it was significantly suppressed by a mucosal pH of 5.5.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2524167

Rapoport, J; Chaimovitz, C; Hays, R M

1989-05-01

235

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

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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

Chapovetsky, Victoria; Katz, U

2003-01-01

236

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

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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.

Phalen David N

2010-06-01

237

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

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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

238

Habitat suitability of patch types: A case study of the Yosemite toad  

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Understanding patch variability is crucial in understanding the spatial population structure of wildlife species, especially for rare or threatened species. We used a well-tested maximum entropy species distribution model (Maxent) to map the Yosemite toad ( Anaxyrus (= Bufo) canorus) in the Sierra Nevada mountains of California. Twenty-six environmental variables were included in the model representing climate, topography, land cover type, and disturbance factors (e.g., distances to agricultural lands, fire perimeters, and timber harvest areas) throughout the historic range of the toad. We then took a novel approach to the study of spatially structured populations by applying the species-environmental matching model separately for 49 consistently occupied sites of the Yosemite toad compared to 27 intermittently occupied sites. We found that the distribution of the entire population was highly predictable (AUC = 0.95±0.03 SD), and associated with low slopes, specific vegetation types (wet meadow, alpine-dwarf shrub, montane chaparral, red fir, and subalpine conifer), and warm temperatures. The consistently occupied sites were also associated with these same factors, and they were also highly predictable (AUC = 0.95±0.05 SD). However, the intermittently occupied sites were associated with distance to fire perimeter, a slightly different response to vegetation types, distance to timber harvests, and a much broader set of aspect classes (AUC = 0.90±0.11 SD). We conclude that many studies of species distributions may benefit by modeling spatially structured populations separately. Modeling and monitoring consistently-occupied sites may provide a realistic snapshot of current species-environment relationships, important climatic and topographic patterns associated with species persistence patterns, and an understanding of the plasticity of the species to respond to varying climate regimes across its range. Meanwhile, modeling and monitoring of widely dispersing individuals and intermittently occupied sites may uncover environmental thresholds and human-related threats to population persistence.

Liang, Christina T.; Stohlgren, Thomas J.

2011-06-01

239

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

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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.

L.H. Gargaglioni

1999-11-01

240

Oxygen uptake of isolated toad skin epithelium: micromeasurement and effect of ionic acclimation.  

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Oxidative metabolism of isolated toad skin epithelium (Bufo viridis) was investigated in vitro under open-circuit conditions using the spectrophotometric oxyhemoglobin micromethod. This highly sensitive technique has been adapted for studying several epithelia in parallel and for detecting possible regional variations of oxygen uptake in individual epithelium. Changes in the proportion of mitochondria-rich cells (MRC) by ionic acclimation affected oxidative metabolism under nontransporting condition. After acclimation of animals to either NaNO3 or NaCl solutions (100 mmol/l, for greater than 2 wk), the number of MRC per square millimeter in epithelia from nonacclimated and NaNO3- and NaCl-acclimated animals was 350 +/- 113, 460 +/- 196, and 107 +/- 52, respectively. O2 uptake of nonacclimated and NaNO3-acclimated epithelia was significantly higher than that of NaCl-acclimated epithelia (i.e., 0.89 and 0.90 vs. 0.57 nmol O2.h-1.mm-2, respectively). The correlation established between O2 uptake and number of MRC allowed evaluation of the respiration rate of one single MRC, i.e., approximately 1 pmol O2/h. The lowest mitochondrial oxidative activity was found in the epithelia from NaCl-acclimated toads where the uncoupler 2,4-dinitrophenol (50 mumols/l) had the highest relative stimulatory effect (+114%). Acetazolamide (50 mumols/l), a potent inhibitor of carbonic anhydrase mainly present in the MRC, reduced selectively by 31% O2 uptake of the MRC-rich epithelia (NaNO3 acclimated). O2 uptake increased significantly by approximately 80% when basolateral pH increased from 5.8 to 7.8, but did not depend on apical pH. These findings indicate that under nontransporting (open-circuit) conditions, aerobic metabolism of the isolated toad skin epithelium is related to the density and/or characteristics of the MRC.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2035617

Raddatz, E; Katz, U; Kucera, P

1991-05-01

 
 
 
 
241

Preferential limb use in relation to epicoracoid overlap in the shoulder girdle of toads.  

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We studied left-right asymmetry in forelimb and hindlimb use in green toads (Bufo viridis) and fire-bellied toads (Bombina bombina) and investigated its possible relationship to the asymmetric structure of the shoulder girdle (epicoracoid overlap) in the latter species. To estimate forelimb use preference we used a modified ''snout-wiping test'' (Bisazza et al., 1997) and to estimate hindlimb use preference we used the ''righting response test'' (Robins et al., 1998). The position of epicoracoids in living animals was determined as proposed earlier (Borkhvardt & Malashichev, 1997). We also examined behavioural laterality in B. viridis to check whether B. viridis is a left-handed species, as it was not clear from the previous study. Our results showed that B. viridis predominantly used the left forelimb and left hindlimb in experimental situations at both the population and individual levels. The same tests were applied to fire-bellied toads, B. bombina, with right or left epicoracoids in the top (dorsal) position. We found that (1) B. bombina is mostly a symmetric species, sometimes using both hands or feet simultaneously; (2) it is ambidextrous in hand and foot use with non-significant left side preference at the population level; (3) there is a positive and significant concordance between the position of epicoracoids and the forelimb preference in B. bombina. Animals with the right epicoracoid in the dorsal position (R. top = L. superficial) prefer to use the right forelimb in the ''snout-wiping test'' and L. top animals predominantly use their left forelimb. PMID:15513184

Malashichev, Yegor B; Nikitina, Natalja G

2002-01-01

242

Endosulfan acute toxicity in Bufo bufo gills: Ultrastructural changes and nitric oxide synthase localization  

International Nuclear Information System (INIS)

ression after 24 and 48 h which may reflect hypoxia and inflammation in the gill epithelium. Our results clearly indicate that short-term exposure to a sublethal concentration of endosulfan, near the high end of the environmental range, disrupts gill morphology and function in B. bufo tadpoles

243

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

Directory of Open Access Journals (Sweden)

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].

Haley BOWCOCK, Gregory P. BROWN, Richard SHINE

2013-12-01

244

Sex recognition and mate choice by male Bufo gargarizans in central China.  

Science.gov (United States)

Mate choice is important for successful reproduction, and consequently species have evolved various ways to choose potential high-quality mates. Anuran mate choice and underlying processes have been the subject of several recent investigations, however we are far from a complete understanding of mate choice in this system. In the present study, when given a simultaneous choice between a male and a female of identical size, males did not discriminate between the sexes, and attempted to clasp a male or a female with equal frequency. Test males only released the stimulus toad when a release call was emitted by the stimulus male. When two males with distinct size differences were provided with a male, the male chose the larger one. Moreover, males discriminated between gravid females that differed in body size, choosing larger gravid females over smaller ones. These results suggest that male Bufo gargarizans can discriminate between the sexes, probably based on male release calls, and prefer to mate with larger individual using visual cues. PMID:22639803

Yu, Tong Lei; Sharma, Manmohan D

2012-06-01

245

Effects of fluoride on metamorphosis, thyroid and skeletal development in Bufo gargarizans tadpoles.  

Science.gov (United States)

This study examined the effects of chronic fluoride exposure on metamorphosis, thyroid and skeletal development in tadpoles of Chinese Toad, Bufo gargarizans. The tadpoles were exposed to fluoride concentrations either at 0, 1, 5, 10, or at 50 mg L(-1) from Gosner stage 26 to Gosner stage 42. Body weight, total length and percentage of tadpoles reaching metamorphosis climax were recorded, and thyroid histological examinations were employed. In addition, mRNA expression of both deiodinase type 2 (D2) and deiodinase type 3 (D3) was analyzed by using RT-PCR and skeletal systems were investigated by using double-staining methodology at stage 42. Results showed that total length and body weight were unaffected by fluoride exposure at all concentrations while metamorphosis was strongly inhibited only by 50 mg L(-1) fluoride. Histomorphological measurements showed the percentage of colloid depletion in thyroid gland increased significantly, while the average diameter of follicles was significantly shorter at 50 mg L(-1) concentration. In addition, fluoride at 5 mg L(-1) can stimulate bone mineralization, while fluoride at 50 mg L(-1) can retard deposition of calcium. In conclusion, our study suggests that 50 mg L(-1) fluoride could damage follicular cells in thyroid gland and induce a sharp reduction in thyroid hormone probably through the up-regulation of D3 mRNA expression, and these influences on thyroid system may delay metamorphosis as well as ossification in bone tissue by inhibiting calcium deposition. PMID:23934448

Zhao, Hongfeng; Chai, Lihong; Wang, Hongyuan

2013-09-01

246

Effects of ionomycin and thapsigargin on ion currents in oocytes of Bufo arenarum.  

Science.gov (United States)

In this study, two electrode voltage clamp technique was used to assess the ionic current of oocytes of the South American toad Bufo arenarum and to study the dependence of these currents on the extracellular and intracellular Ca2+ concentrations. Ca2+ chelators, ionomycin -a calcium ionophore- and thapsigargin, a blocker of the Ca2+ pump of the sarcoplasmic reticulum, were used. The main results were the following: Most oocytes showed a voltage activated rectifying conductance. Ionomycin (1 microM) increased inward and outward currents in control solution. The effect of ionomycin was blocked partially at negative potentials and was blocked completely at positive potentials in absence of extracellular Ca2+. When the oocytes were treated with thapsigargin (2 microM) or BAPTA-am, a membrane-permeant intracellular chelator in control solution (10 microM), ionomycin did not increased either inward nor outward currents. The conclusion of our experiments is that there are two sources of Ca2+ for activation of the current induced by ionomycin, the cytoplasmic stores and the extracellular space. We believe ionomycin directly translocates Ca2+ from the SER into the cytoplasm but not from the extracellular medium. Ca2+ entry probably occurs through store-operated-Ca-channels. PMID:12945749

Cavarra, M Soledad; Assef, Yanina A; Kotsias, Basilio A

2003-06-01

247

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

Energy Technology Data Exchange (ETDEWEB)

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.

Dorchin, A., E-mail: adorchin@campus.haifa.ac.i [Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Mount Carmel, Haifa 31905 (Israel); Shanas, U., E-mail: shanas@research.haifa.ac.i [Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Mount Carmel, Haifa 31905 (Israel); Department of Biology, Faculty of Natural sciences, University of Haifa - Oranim, Tiv' on 36006 (Israel)

2010-12-15

248

Morphology of the kidney in larvae of Bufo viridis (Amphibia, Anura, Bufonidae).  

Science.gov (United States)

This study deals primarily with the morphology and ultrastructure of the pronephros in the green toad Bufo viridis during prometamorphosis when the pronephros and the developing mesonephros function simultaneously. Furthermore, the mesonephros was studied during pro- and postmetamorphosis with emphasis on the distal segments of the nephron. The paired kidneys consist of two cranial pronephroi immediately behind the gill region and two more caudal elongated mesonephroi. Each pronephros consists of a single convoluted tubule which opens into the coelom via three nephrostomes. This tubule is divided into three ciliated tubules, three proximal tubule branches, a common proximal tubule and a distal tubule, which in turn continues into the nephric duct. No intermediate segment is present. The length of the pronephric tubule is 12 mm, including the three branches of the ciliated tubules and proximal tubules. Primary urine is formed upon filtration from an external glomerulus, which is a convoluted capillary lined by podocytes, a specialization of the coelomic epithelium. From the coelom the filtrate is swept into the ciliated tubules. In the collecting duct system of the developing mesonephric nephron epithelial cells with conspicuous, apical osmiophilic granules appear in larvae of 9-10 mm. Heterocellularity of mixed intercalated (mitochondria rich) cells and principal cells is observed in the collecting duct system and nephric duct from a larval body length of 14 mm. As the proliferation of mitochondria-rich cells proceeds, the osmiophilic granules disappear and are completely absent from the adult amphibian mesonephros. PMID:10972968

Møbjerg, N; Larsen, E H; Jespersen, A

2000-09-01

249

Diet alters species recognition in juvenile toads.  

Science.gov (United States)

Whether environmental effects during juvenile development can alter the ontogeny of adult mating behaviour remains largely unexplored. We evaluated the effect of diet on the early expression of conspecific recognition in spadefoot toads, Spea bombifrons. We found that juvenile toads display phonotaxis behaviour six weeks post-metamorphosis. However, preference for conspecifics versus heterospecifics emerged later and was diet dependent. Thus, the environment can affect the early development of species recognition in a way that might alter adult behaviour. Evaluating such effects is important for understanding variation in hybridization between species and the nature of species boundaries. PMID:24088562

Pfennig, Karin S; Moncalvo, Verónica G Rodriguez; Burmeister, Sabrina S

2013-10-23

250

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

Science.gov (United States)

...Revised Critical Habitat for the Arroyo Toad AGENCY: Fish and Wildlife Service, Interior...designation of critical habitat for the arroyo toad (Anaxyrus californicus) under the Endangered...designation of critical habitat for the arroyo toad; revisions to proposed critical...

2010-06-29

251

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

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

2010-02-01

252

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

Directory of Open Access Journals (Sweden)

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

Ning Wang

2010-02-01

253

Toad poisoning in three dogs: case reports  

Scientific Electronic Library Online (English)

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

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

254

Comparing and Contrasting with Frog and Toad  

Science.gov (United States)

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

Childs, Rebecca

2012-04-09

255

Reported Experiences Enhance Favourable Attitudes toward Toads  

Science.gov (United States)

There are many factors that influence the formation of attitudes, one of the most crucial ones being education. Positive attitudes toward animals can be effectively accomplished principally by enabling students to directly experience organisms and their environments. The following study presents the development of a Toad Attitude Questionnaire…

Tomazic, Iztok

2011-01-01

256

Stabilizing and directional female choice for male calls in the European green toad.  

Science.gov (United States)

We analysed variation in three temporal (pulse rate, call and intercall duration) and one spectral (fundamental frequency) acoustic properties of the green toad's, Bufo viridis, advertisement call, at different levels, from the single bout of an individual to between populations. Independent of the level, pulse rate and fundamental frequency were less variable than intercall and call durations. The former were classified as static, the latter as dynamic properties of the signal. We analysed the effects of body size and temperature, assumed to represent, respectively, morphological and physiological constraints on the signals. Static properties were under strong constraints, either morphologically (fundamental frequency) or physiologically (pulse rate), whereas no significant effects of size and temperature were observed on dynamic properties. We used two-choice discrimination experiments to investigate females' preferences for call properties. Females preferred extreme to mean values of the dynamic properties, even when these fell above the typical range of variation of the population. In contrast, females had weak preferences for mean values, and for lower than average compared with higher than average values, of static properties. We discuss the hypothesis that static and dynamic call properties may convey different information to females: static properties may be important for species recognition, whereas dynamic properties may be important for mate selection.1998 The Association for the Study of Animal Behaviour PMID:9787018

Castellano; Giacoma

1998-08-01

257

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

Directory of Open Access Journals (Sweden)

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 Diversas espécies de rãs terrestres, tartarugas e insetos desenvolveram mecanismos para resistência ao congelamento, como o aumento dos níveis de glicose, proteínas anticongelantes e enzimas antioxidantes. Neste estudo, verificou-se a importância da glicose para a crioresistência de dois anfíbios anuros: a rã Rana catesbeiana e o sapo Bufo paracnemis. Os animais foram expostos a -2ºC para medidas de glicemia, conteúdo de glicogênio muscular e hepático, hematócrito e volume celular das hemácias. As rãs sobreviveram à exposição, enquanto os sapos não. A glicemia aumentou de 40,35 ± 7,25 para 131,87 ± 20,72 mg/dl (P < 0.01 quando as rãs foram transferidas de 20 para -2ºC. Este acúmulo de glicose em resposta à exposição ao frio foi acompanhado por uma redução (P < 0.05 no conteúdo de glicogênio hepático de 3,94 ± 0,42 para 1,33 ± 0,36 mg/100 mg de tecido, indicando que o catabolismo do glicogênio hepático foi, provavelmente, a principal fonte de carbono para a síntese de glicose, enquanto o glicogênio muscular parace ser de menor importância. Nos sapos, a hiperglicemia induzida pelo frio foi relativamente menor (de 27,25 ± 1,14 para 73,72 ± 13,50 mg/dl; P < 0.05 e não verificou-se variação significativa no conteúdo de glicogênio muscular e hepático. A exposição a -2ºC não teve efeito sobre o hematócrito das rãs, mas reduziu significativamente (P < 0.01 o hematócrito dos sapos de 20,0 ± 2,1% para 5,8 ± 1,7%, devido a uma redução do volume das hemácias (de 1532 ± 63 para 728 ± 87 mm³. Quando glicose foi injetada nos sapos, a glicemia elevou-se a níveis similares àqueles das rãs e o hematócrito não variou, mesmo assim os sapos não se tornaram crioresistentes. Em conclusão, a deficiência no catabolismo da glicose, induzido pelo frio, não parece ser o único mecanismo responsável pela intolerância ao congelamento de Bufo paracnemis, uma espécie não tolerante ao congelamento.

A. A. STEINER

2000-05-01

258

Invasive Cane Toads: Social Facilitation Depends upon an Individual's Personality  

Science.gov (United States)

Individual variation in behavioural traits (including responses to social cues) may influence the success of invasive populations. We studied the relationship between sociality and personality in invasive cane toads (Rhinella marina) from a recently established population in tropical Australia. In our field experiments, we manipulated social cues (the presence of a feeding conspecific) near a food source. We captured and compared toads that only approached feeding sites where another toad was already present, with conspecifics that approached unoccupied feeding sites. Subsequent laboratory trials showed correlated personality differences (behavioural syndromes) between these two groups of toads. For example, toads that approached already-occupied rather than unoccupied feeding sites in the field, took longer to emerge from a shelter-site in standardized trials, suggesting these individuals are ‘shy’ (whereas toads that approached unoccupied feeding stations tended to be ‘bold’). Manipulating hunger levels did not abolish this difference. In feeding trials, a bold toad typically outcompeted a shy toad under conditions of low prey availability, but the outcome was reversed when multiple prey items were present. Thus, both personality types may be favored under different circumstances. This invasive population of toads contains individuals that exhibit a range of personalities, hinting at the existence of a wide range of social dynamics in taxa traditionally considered to be asocial. PMID:25033047

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

2014-01-01

259

Caller ID: The Frog - and Toad! - Mating Game  

Science.gov (United States)

This activity is a sensory experience that recreates the sounds of a pond at night. It can serve first as an introduction to frog and toad communication and second, as a demonstration of the calling system used by frogs and toads during breeding season. During the activity, learners investigate how frogs and toads find each other by using calls, and then try to mimic this idea by using their own unique "sound pattern" to find their partner. Learners also discover that scientists can identify frogs and toads by their calls.

Aquariums, Association O.

2014-01-01

260

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

Scientific Electronic Library Online (English)

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

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

2013-12-01

 
 
 
 
261

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese O comportamento respiratório em repouso de Bufo marinus é descrito em animais minimamente implantados por um período de 24 horas, durante as quais os animais permanecem em total isolamento. Um estado de torpor associado a longas apnéias é descrito, e suas implicações sobre os níveis de gases sanguín [...] eos é investigada. Os resultados mostram que o ritmo ventilatório em repouso de Bufo marinus é muito mais baixo do que o relatado na literatura até o presente. Os níveis arteriais de oxigênio, dióxido de carbono e pH foram monitorados durante longas apnéias induzidas artificialmente por meio de anestesia. Os sapos demonstraram capacidade surpreendente de eliminar dióxido de carbono por meios não respiratórios mesmo estando confinados em uma caixa plástica seca sem acesso a água. A pressão parcial de oxigênio arterial caiu a níveis extremamente baixos após uma hora de apnéia. Esses resultados sugerem que esses animais podem suportar muito bem hipoxia severa por longos períodos durante o estado de torpor. Abstract in english 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 ventilati [...] on rate of Bufo marinus is much lower than that reported so far. Levels of arterial oxygen, carbon dioxide, and pH are monitored during artificial long apneas induced by anesthesia. The toads showed an unexpected ability to unload carbon dioxide by non-respiratory means, even while being kept on dry plastic box with no access to water. Oxygen arterial partial pressure dropped to very low levels after one hour of apnea. This suggests that these animals may endure very well severe hypoxia for long periods of time while in torpor.

F. C., Coelho; N. J., Smatresk.

262

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

Science.gov (United States)

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...

263

THE EFFECT OF SUBSTRATE TYPE ON AVOIDANCE OF UREA IN JUVENILE WESTERN TOADS (BUFO BOREAS). (U915529)  

Science.gov (United States)

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...

264

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

DEFF Research Database (Denmark)

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

Overgaard, Johannes; Andersen, Jonas Lembcke

2012-01-01

265

Two-dimensional countercurrent chromatography × high performance liquid chromatography for preparative isolation of toad venom.  

Science.gov (United States)

In this work, a new on-line two-dimensional chromatography coupling of flow programming counter-current chromatography and high-performance liquid chromatography (2D CCC×HPLC) was developed for preparative separation of complicated natural products. The CCC column was used as the first dimensional isolation and a preparative ODS column operated in reversed-phase (RP) mode as the second dimension. The CCC was operated at a controlled flow rate to ensure that each fraction eluted within one hour, corresponding to the isolation time of the 2nd dimensional preparative HPLC. The eluent from the 1st dimensional CCC was diluted using a makeup pump and trapped onto holding column, before been eluted and transferred to the 2nd dimensional HPLC. The performance of the holding column was evaluated, in terms of column size, dilution ratio and diameter-height ratio, as well as system pressure, for the solution to the issue of online trapping of low pressure eluent from a CCC column. Satisfactory trapping efficiency and tolerable CCC pressure can be achieved using a commercially available 15mm×30mm i.d. ODS pre-column. The present integrated system was successfully applied in a one-step preparative separation of 12 compounds, from the crude methanol extract of venom of Bufo bufo gargarizans. Compounds 1-12 were isolated in overall yield of 1.0%, 0.8%, 2.0%, 1.3%, 2.0%, 1.5%, 1.9%, 3.6%, 6.1%, 4.8%, 3.5% and 4.1%, with HPLC purity of 99.9%, 99.7%, 90.6%, 99.9%, 77.0%, 99.9%, 90.4%, 99.9%, 52.0%, 99.9%, 99.3%, and 85.0%, respectively. All the results demonstrate that the flow programming CCC×HPLC method is an efficient and convenient way for the separation of compounds from toad venom and it can also be applied to isolate other complex multi-component natural products. PMID:24484689

Qiu, Ying-Kun; Yan, Xia; Fang, Mei-Juan; Chen, Lin; Wu, Zhen; Zhao, Yu-Fen

2014-02-28

266

Estereoultraestructura del pulmón de anuros bufónidos. Bufo arenarum  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Scanning electron microscopy was used to determined the inner morphology of the Bufo arenarum lung. The observations let conclude that the lung presents three types of folds which divide the organ into alveolar spaces. The inner surface of the lung, as well as the lateral wall of the folds are lined with respiratory epithelium, except in the apex of the primary folds (ciliated surface with goblet cells) and in the secondary folds (ciliated surface).

Hermida, Gladys N.; Fiorito, Luisa E.

1994-01-01

267

Estereoultraestructura del pulmón de anuros bufónidos. Bufo arenarum  

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Full Text Available Scanning electron microscopy was used to determined the inner morphology of the Bufo arenarum lung. The observations let conclude that the lung presents three types of folds which divide the organ into alveolar spaces. The inner surface of the lung, as well as the lateral wall of the folds are lined with respiratory epithelium, except in the apex of the primary folds (ciliated surface with goblet cells and in the secondary folds (ciliated surface.

Hermida, Gladys N.

1994-01-01

268

Effects of cyclic AMP and theophylline on chloride conductance across toad skin.  

Science.gov (United States)

1. The effects of the phosphodiesterase inhibitors theophylline and isobutylmethylxanthine (IBMX) on baseline and voltage-activated Cl- conductance (gCl) of toad skin were compared with those of the potent 2-chlorophenylthio analogue of cAMP (CPT-cAMP). 2. Using intact and split skins of Bufo viridis we confirmed that theophylline and IBMX raised the voltage-activated gCl with a pattern identical to that seen under control conditions. This effect was small or missing if gCl was already high in the control. 3. CPT-cAMP, in contrast, increased the Cl(-)-specific conductance by up to 6 mS cm-2 at short circuit. The characteristic time-dependent, slow activation of gCl by serosa-positive clamp potentials was completely lost under these conditions. 4. Coinciding with the loss of voltage activation of gCl the plateau value of the Lorentzian component of fluctuation in current at serosa-positive clamp potentials decreased by almost 50%. The corner frequencies were not notably different. 5. After CPT-cAMP, the sigmoidal voltage-conductance relation that is characteristic of control conditions or after theophylline disappeared; the patterns were variable and incompatible with voltage activation. 6. The voltage-activated gCl under control conditions and with theophylline was blocked by mucosal NO3-, I- or SCN-, the last two being almost equally effective. In the presence of CPT-cAMP, mucosal NO3- had minimal influence on tissue conductance, whereas the effects of I- and SCN- were essentially unchanged. Br- on the mucosal side could substitute for Cl- under all conditions. 7. The results suggest that protein phosphorylation by supramaximal concentrations of cAMP induces maximal conductance through anion-specific routes, while the voltage sensitivity of this pathway is lost. The effects of theophylline and IBMX on the voltage-activated Cl-conductance of toad skin cannot be explained solely by inhibition of the phosphodiesterase. PMID:8583395

Katz, U; Nagel, W

1995-11-15

269

Further Hopping with Toads and Frogs  

CERN Document Server

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.

Thanatipanonda, Thotsaporn ``Aek''

2008-01-01

270

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

DEFF Research Database (Denmark)

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

Harck, A F; Larsen, Erik Hviid

1986-01-01

271

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

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

Azevedo MFC

2003-01-01

272

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

Scientific Electronic Library Online (English)

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

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

273

Dynamics and density of mitochondria-rich cells in toad skin epithelium.  

Science.gov (United States)

The dynamics of change in mitochondria-rich (MR) cells density in the skin epithelium of Bufo viridis was studied on skin biopsies taken in vivo, throughout experimental periods lasting up to 3 months. When the bathing solution contained Cl-, MR cells' density (Dmrc) greatly decreased. There was one exception, when the acclimation solution was KCl, Dmrc in the skin increased. The rate of decrease in Dmrc depended on the mode of acclimation. When bath NaCl concentration was elevated slowly in small increments, the change in Dmrc was very slow. A regression line was calculated for the rate of decrease in the density of MR cells. An equation in the form of y = 1574 - 10.23x (where x = days; R2 = 0.626) was obtained with bath NaCl that was elevated from 30 to 200 mmol/l, in 45 days. Oxytocin (60 mU/ml) increased sodium transport, independently and without effect on Cl- conductance. Theophylline (1 mmol/l), which leads also to elevation of cellular cAMP in contrast, increased Na+ transport, but elevated Cl- conductance 3-4 times as well. Cl- conductance that is activated by transepithelial potential was much lower in skin from hyperosmotic NaCl-acclimated toads, as compared with that in skin from tap water-acclimated animals. Our experiments confirm that MR cells are a major pathway for Cl- conductance, as suggested earlier. However, the density of these cells in the skin epithelium of B viridis depends not only on bath NaCl concentration, but also on the mode of acclimation of the animals. Since transport functions other than gCl reside in the amphibian skin MR cells, the density of MR cells must also depend on these functions. These functions, and the mechanisms responsible for the down and up regulation of MR cells' density, remain to be established. PMID:8785520

Katz, U; Gabby, S

1995-01-01

274

A novel fast optical switch based on two cascaded Terahertz Optical Asymmetric Demultiplexers (TOAD).  

Science.gov (United States)

A novel optical switch based on cascading two terahertz optical asymmetric demultiplexers (TOAD) is presented. By utilizing the sharp edge of the asymmetric TOAD switching window profile, two TOAD switching windows are overlapped to produce a narrower aggregate switching window, not limited by the pulse propagation time in the SOA of the TOAD. Simulations of the cascaded TOAD switching window show relatively constant window amplitude for different window sizes. Experimental results on cascading two TOADs, each with a switching window of 8ps, but with the SOA on opposite sides of the fiber loop, show a minimum switching window of 2.7ps. PMID:19424325

Wang, Bing; Baby, Varghese; Tong, Wilson; Xu, Lei; Friedman, Michelle; Runser, Robert; Glesk, Ivan; Prucnal, Paul

2002-01-14

275

Biogeographic patterns of Colombian frogs and toads  

International Nuclear Information System (INIS)

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

276

Spadefoot toads break the rules in dry weather  

Science.gov (United States)

Desert-dwelling animals have all kinds of clever tricks for surviving in their dry environments. This includes the spadefoot toad, which is named for the hard, pointy "spade" on its hind feet, which is used for digging.

American Association for the Advancement of Science (AAAS;)

2007-11-08

277

Purification of bufadienolides from the skin of Bufo bufo gargarizans Cantor with positively charged C18 column.  

Science.gov (United States)

As a kind of promising anticancer compounds, the preparation of bufadienolides is a hot study spot. However, due to the complexity of biological sample, the purification of bufadienolides from a crude sample (toad skin) is a tough work. In this paper, we reported a new way based on positively charged C18 material (XCharge C18) to quickly separate and purify bufadienolides from toad skin. By this method, the different ionic feature of the amino acid conjugated bufadienolides (AACBs) and the free form bufadienolides (AAUBs) was firstly utilized to obtain distinct separation selectivity on the XCharge C18 column. Additionally, the peak tailing problem of AACBs on conventional C18 was resolved and better resolutions were achieved on the XCharge C18, thus, two kinds of bufadienolides on one column were successfully purified respectively. Taking F13 as an example, the method was validated by liquid chromatography-mass spectrometry (LC-MS), and then 4 AACBs as well as 4 AAUBs were simultaneously purified by preparative XCharge C18. In addition, the application of this method in other fractions was also validated. The results suggested that the developed method is a practical and promising tool for efficient separation and purification of bufadienolides from toad skin. PMID:24503198

Li, Xiaolong; Guo, Zhimou; Wang, Chaoran; Shen, Aijin; Liu, Yanfang; Zhang, Xiuli; Zhao, Weijie; Liang, Xinmiao

2014-04-01

278

Do invasive cane toads affect the parasite burdens of native Australian frogs?  

Science.gov (United States)

One of the most devastating impacts of an invasive species is the introduction of novel parasites or diseases to native fauna. Invasive cane toads (Rhinella marina) in Australia contain several types of parasites, raising concern that the toads may increase rates of parasitism in local anuran species. We sampled cane toads and sympatric native frogs (Limnodynastes peronii, Litoria latopalmata, and Litoria nasuta) at the southern invasion front of cane toads in north-eastern New South Wales (NSW). We dissected and swabbed these anurans to score the presence and abundance of nematodes (Rhabdias lungworms, and gastric encysting nematodes), myxozoans, and chytrid fungus. To determine if cane toad invasion influences rates of parasitism in native frogs, we compared the prevalence and intensity of parasites in frogs from areas with toads, to frogs from areas without toads. Contrary to the situation on the (rapidly-expanding) tropical invasion front, cane toads on the slowly-expanding southern front were heavily infected with rhabditoid lungworms. Toads also contained gastric-encysting nematodes, and one toad was infected by chytrid fungus, but we did not find myxozoans in any toads. All parasite groups were recorded in native frogs, but were less common in areas invaded by toads than in nearby yet to be invaded areas. Contrary to our predictions, toad invasion was associated with a reduced parasite burden in native frogs. Thus, cane toads do not appear to transfer novel parasites to native frog populations, or act as a reservoir for native parasites to 'spill-back' into native frogs. Instead, cane toads may reduce frog-parasite numbers by taking up native parasites that are then killed by the toad's immune defences. PMID:24533330

Lettoof, Damian C; Greenlees, Matthew J; Stockwell, Michelle; Shine, Richard

2013-12-01

279

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

International Nuclear Information System (INIS)

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

280

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

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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.

Asucena Naupay

2014-06-01

 
 
 
 
281

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

Scientific Electronic Library Online (English)

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

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

282

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

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

Jara, Fabián Gastón

2006-03-01

283

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

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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.

David Arome

2014-07-01

284

Clinical and electrocardiographic evaluation during experimental toad poisoning in dogs  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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 eva [...] luate 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

AC, Camplesi; M, Sakate; NMB, Simão; R, Marucio; FCD, Mota; CF, Moya-Araujo.

285

TOAD: a numerical model for the 4MOST instrument  

Science.gov (United States)

TOAD, the "Top Of the Atmosphere to Detector" simulator, is a primary engineering tool that accompanies the development of the 4MOST instrument. The ultimate goal is to provide a detailed, end-to-end performance model of 4MOST by providing the detector image for an artificial target field with less then 5% error. TOAD will be able to create a realistic output for any reasonable input. The input can be anything, from point sources through extended sources, calibration lamps or stray-light, entering the system at virtually any point in a optical path. During the development of the 4MOST facility, the TOAD simulator will give invaluable insight into the interaction of various parts of the instrument and the impact of engineering design decisions on the system performance.

Winkler, Roland; Haynes, Dionne M.; Bellido-Tirado, Olga; Xu, Wenli; Haynes, Roger

2014-08-01

286

Diet of Physalaemus cf. cicada (Leptodactylidae and Bufo granulosus (Bufonidae in a semideciduous forest Dieta de Physalaemus cf. cicada (Leptodactylidae e Bufo granulosus (Bufonidae em uma floresta semidecídua  

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Full Text Available We determined the diet of the two most abundant anuran species which occur in the litter of a semideciduous forest (Lençóis, Bahia, Brazil, Physalaemus cf. cicada and Bufo granulosus in the dry and rainy seasons. Pitfall traps were used to collect anuran and invertebrate fauna, which showed the availability of prey in the environment. Physalaemus cf. cicada was present in both seasons and Bufo granulosus only in the rainy season. Both species fed mainly on Isoptera and Formicidae. However, there is a difference between the rainy and dry seasons concerning the diet of P. cf. cicada. During the rainy season P. cf. cicada consumed less Isoptera and more Formicidae than in the dry season. In the volumetric sense, Orthoptera was the most important alimentary category for P. cf. cicada and B. granulosus. The Jacobs’ electivity index indicated that Physalaemus cf. cicada and Bufo granulosus were specialists in Isoptera.Foi determinada a dieta das duas espécies mais abundantes de anuros que ocorrem na serrapilheira de uma floresta semidecídua (Lençóis, Bahia, Brasil, Physalaemus cf. cicada e Bufo granulosus, nas estações seca e chuvosa. Armadilhas de queda foram usadas para a coleta de anuros e fauna de invertebrados que indicaram a disponibilidade de presas no ambiente. Physalaemus cf. cicada estava presente em ambas as estações e Bufo granulosus, só na estação chuvosa. Ambas as espécies alimentaram-se principalmente de Isoptera e Formicidae. Porém, houve uma diferença entre estações chuvosa e seca relativo à dieta de P. cf. cicada. Durante a estação chuvosa, P. cf. cicada consumiu menos Isoptera e mais Formicidae que na estação seca. Volumetricamente, Orthoptera foi a categoria alimentar mais importante para P. cf. cicada e B. granulosus. O índice de eletividade de Jacobs indicou que Physalaemus cf. cicada e Bufo granulosus são especialistas em Isoptera.

AS. Santana

2007-02-01

287

Diet of Physalaemus cf. cicada (Leptodactylidae) and Bufo granulosus (Bufonidae) in a semideciduous forest / Dieta de Physalaemus cf. cicada (Leptodactylidae) e Bufo granulosus (Bufonidae) em uma floresta semidecídua  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Foi determinada a dieta das duas espécies mais abundantes de anuros que ocorrem na serrapilheira de uma floresta semidecídua (Lençóis, Bahia, Brasil), Physalaemus cf. cicada e Bufo granulosus, nas estações seca e chuvosa. Armadilhas de queda foram usadas para a coleta de anuros e fauna de invertebra [...] dos que indicaram a disponibilidade de presas no ambiente. Physalaemus cf. cicada estava presente em ambas as estações e Bufo granulosus, só na estação chuvosa. Ambas as espécies alimentaram-se principalmente de Isoptera e Formicidae. Porém, houve uma diferença entre estações chuvosa e seca relativo à dieta de P. cf. cicada. Durante a estação chuvosa, P. cf. cicada consumiu menos Isoptera e mais Formicidae que na estação seca. Volumetricamente, Orthoptera foi a categoria alimentar mais importante para P. cf. cicada e B. granulosus. O índice de eletividade de Jacobs indicou que Physalaemus cf. cicada e Bufo granulosus são especialistas em Isoptera. Abstract in english We determined the diet of the two most abundant anuran species which occur in the litter of a semideciduous forest (Lençóis, Bahia, Brazil), Physalaemus cf. cicada and Bufo granulosus in the dry and rainy seasons. Pitfall traps were used to collect anuran and invertebrate fauna, which showed the ava [...] ilability of prey in the environment. Physalaemus cf. cicada was present in both seasons and Bufo granulosus only in the rainy season. Both species fed mainly on Isoptera and Formicidae. However, there is a difference between the rainy and dry seasons concerning the diet of P. cf. cicada. During the rainy season P. cf. cicada consumed less Isoptera and more Formicidae than in the dry season. In the volumetric sense, Orthoptera was the most important alimentary category for P. cf. cicada and B. granulosus. The Jacobs’ electivity index indicated that Physalaemus cf. cicada and Bufo granulosus were specialists in Isoptera.

AS., Santana; FA., Juncá.

288

Behavioral responses of bufo arenarum tadpoles to odonate naiad predation  

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Full Text Available Abstract.—In the presence of predators, anuran tadpoles often exhibit behavioral plasticity, which in turn reduces predationrisk. We evaluated indirect effects of odonate larva predation on activity of Bufo arenarum tadpoles. We reared intact andtail-damaged larvae in three different predator treatments: (1 caged predators fed tadpoles; (2 caged predators that werestarved; and (3 no predators. Both intact and damaged tadpoles were significantly less active when exposed to predator cues.There were no differences in activity between tadpoles with damaged and intact tails, however significant differences wereobserved between fed and starved predator treatments. Our results are consistent with other studies that have shown bufonidtadpoles reduce activity when exposed to predator cues and address a novel contribution of southern-hemisphere bufonid,expanding the knowledge of that family in ecological experiments.

MARIANA PUETA

2006-12-01

289

Interplay among nocturnal activity, melatonin, corticosterone and performance in the invasive cane toad (Rhinella marinus).  

Science.gov (United States)

Most animals conduct daily activities exclusively either during the day or at night. Here, hormones such as melatonin and corticosterone, greatly influence the synchronization or regulation of physiological and behavioral cycles needed for daily activity. How then do species that exhibit more flexible daily activity patterns, responses to ecological, environmental or life-history processes, regulate daily hormone profiles important to daily performance? This study examined the consequences of (1) nocturnal activity on diel profiles of melatonin and corticosterone and (2) the effects of experimentally increased acute melatonin levels on physiological and metabolic performance in the cane toad (Rhinella marinus). Unlike inactive captive toads that had a distinct nocturnal melatonin profile, nocturnally active toads sampled under field and captive conditions, exhibited decreased nocturnal melatonin profiles with no evidence for any phase shift. Nocturnal corticosterone levels were significantly higher in field active toads than captive toads. In toads with experimentally increased melatonin levels, plasma lactate and glucose responses following recovery post exercise were significantly different from control toads. However, exogenously increased melatonin did not affect resting metabolism in toads. These results suggest that toads could adjust daily hormone profiles to match nocturnal activity requirements, thereby avoiding performance costs induced by high nocturnal melatonin levels. The ability of toads to exhibit plasticity in daily hormone cycles, could have broad implications for how they and other animals utilize behavioral flexibility to optimize daily activities in response to natural and increasingly human mediated environmental variation. PMID:25063397

Jessop, Tim S; Dempster, Tim; Letnic, Mike; Webb, Jonathan K

2014-09-15

290

Phospholipid transfer activities in toad oocytes and developing embryos  

International Nuclear Information System (INIS)

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

291

Clinical and electrocardiographic evaluation during experimental toad poisoning in dogs  

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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.

AC Camplesi

2010-01-01

292

Author! Author! Creator of Frog and Toad: Arnold Lobel  

Science.gov (United States)

This article presents a brief biography of author Arnold Lobel, perhaps best known for giving the world Frog and Toad. Arnold Lobel was born in Los Angeles, California, on May 22, 1933, and was raised by his grandparents in New York. He loved checking out books from the library when he was a little boy and sharing with his classmates the stories…

Brodie, Carolyn S.

2005-01-01

293

WEAKLY SYNCHRYRONIZED SUBPOPULATION DYNAMICS IN WISCONSIN FROGS AND TOADS  

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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...

294

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

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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.

Ewa Krzysztofowicz

2011-08-01

295

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

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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-...

Sadek, I. A.; Abou-gabal, A.

1999-01-01

296

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

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

Anger Jean-Pierre

2008-02-01

297

A new species of Bufo Laurenti (Anura, Bufonidae) from northeastern Brazil  

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Full Text Available SciELO Brazil | Language: English Abstract in english A new species of bufonid load, Bufo jimi sp. nov., is described from Maracás and Itagibá, State of Bahia, Brazil. This species shows close relationships to B. paracnemis Lutz, 1925 by sharing the presence of tibial glands and the paratoid glands shape. The new species is a member of the Bufo marinus [...] -group, and is characlerized by having well-defined glands in most part of dorsal faceof the forearms, in the extcrn side of the feet and in both sides of cloacal region.

Maria Nazaré, Stevaux.

298

A new species of Bufo Laurenti (Anura, Bufonidae from northeastern Brazil  

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Full Text Available A new species of bufonid load, Bufo jimi sp. nov., is described from Maracás and Itagibá, State of Bahia, Brazil. This species shows close relationships to B. paracnemis Lutz, 1925 by sharing the presence of tibial glands and the paratoid glands shape. The new species is a member of the Bufo marinus-group, and is characlerized by having well-defined glands in most part of dorsal faceof the forearms, in the extcrn side of the feet and in both sides of cloacal region.

Maria Nazaré Stevaux

2002-07-01

299

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

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

Marlene Soares Dias, Alves.

300

The supercritical CO? extract from the skin of Bufo bufo gargarizans Cantor blocks hepatitis B virus antigen secretion in HepG2.2.15 cells.  

Science.gov (United States)

The skin of Bufo bufo gargarizans Cantor has long been used for the treatment of hepatitis B in China and supercritical carbon dioxide extraction (SC-CO?) is widely used in extracting active ingredients from natural products. The aim of present study was to assess the anti-hepatitis B virus (HBV) effect of the supercritical CO? extract from the skin of Bufo bufo gargarizans Cantor (SCE-BC). Cytotoxicity of SCE-BC was analyzed using an MTT [3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide] assay in HepG2.2.15 cells. The hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), and hepatitis B core-related antigen (HBcrAg) concentrations in cell culture medium were determined by chemiluminescent enzyme immunoassay. HBV mRNA in cells was determined using real-time polymerase chain reaction. SCE-BC concentrations below 10(-2) ?g/mL had no significant toxicity to HepG2.2.15 cells. SCE-BC at 10(-4) ?g/mL effectively inhibited the secretion of HBeAg by 23.36% on day 6. It was more potent than the positive control lamivudine (100 ?g/mL) in terms of the inhibition of HBeAg and HBcrAg secretion on day 6. Consistent with the HBV antigen reduction, HBV mRNA expression was markedly inhibited in comparison to the control when HepG2.2.15 cells were treated with SCE-BC. Moreover, SCE-BC had greater inhibitory activity with respect to HBeAg than to HBsAg. Since HBeAg promotes immune tolerance and persistent infection during HBV infection, the present results suggest that immune tolerance induced by HBeAg might be overcome by SCE-BC. Therefore, SCE-BC warrants further investigation. PMID:24647111

Cui, Xiaoyan; Inagaki, Yoshinori; Wang, Dongliang; Gao, Jianjun; Qi, Fanghua; Gao, Bo; Kokudo, Norihiro; Fang, Dingzhi; Tang, Wei

2014-02-01

 
 
 
 
301

Lankesterella poeppigii n. sp. (Apicomplexa, Lankesterellidae) from Bufo poeppigii (Tschudi, 1845) from Peru / Lankesterella poeppigii n. sp. (Apicomplexa, Lankesterellidae) de Bufo poeppigii (Tschudi, 1845) del Perú  

Scientific Electronic Library Online (English)

Full Text Available SciELO Peru | Language: English Abstract in spanish Lankesterella poeppigii n. sp. es descrita de Bufo poeppigii (Tschudi, 1845) del Perú. La merogonia y oogonia se producen en el endotelio capilar y los macrófagos en el hígado, el bazo y los riñones. Los esquizontes son ovalados, 25,2-29,4 x 15,7-16,8 micras de tamaño y producen 35-46 merozoitos. Lo [...] s ooquistes miden 26,3-29,4 x 15,1-17,6 micras de tamaño; esporozoitos, reunidos en los macrófagos, miden 9,2-9,8 x 4,2-5,0 micras de tamaño. Liberados, los esporozoitos miden 8,7-9,8 x 2,8-3,1 micras y entran en los eritrocitos. Lankesterella poeppigii es comparada con L. petiti Lainson y Paperna, 1995, que infecta a Bufo marinus (Linnaeus, 1758) en Brasil. Los caracteres específicos citados, sumados a las diferencias entre los huespédes y en la localización geográfica justifican la clasificación de la Lankesterella de B. poeppigii como una nueva especie. Abstract in english Lankesterella poeppigii n. sp. is described from Bufo poeppigii (Tschudi, 1845) from Peru. Merogony and oogony occur in the capillary endothelium and the macrophages in the liver, spleen and kidneys. Meronts are oval, 25,2-29,4 x 15,7-16,8 µm in size and yield 35-46 merozoites. Oocysts are 26,3-29,4 [...] x 15,1-17,6 µm in size; sporozoites 9,2-9,8 x 4,2-5,0 µm in size, assemble in macrophages. Released 8,7-9,8 x 2,8-3,1 µm sporozoites enter erythrocytes. L. poeppigii is compared with Lankesterella petiti Lainson & Paperna, 1995 infecting Bufo marinus (Linnaeus, 1758) in Brazil. The above mentioned specific characters, added to differences in hosts and geographical location warrant the description of Lankesterella poeppigii from B. poeppigii as a new species.

Ilan, Paperna; Patrick, Bastien; Jean-Marc, Chavatte; Irène, Landau.

302

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

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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.

Fabio Casale

2006-11-01

303

Species-specificity of amphibia carbohydrate chains: the Bufo viridis case study.  

Science.gov (United States)

The jelly coat surrounding the eggs of amphibia is composed of oviducal mucins and plays an important role in the fertilization process. From a structural and chemical point of view, these jellies are very different from one species to another. Bufo viridis is the 13th amphibia species studied in term of carbohydrate structural analysis. The oligosaccharides have been released from the oviducal mucins by reductive beta elimination, purified by various chromatography procedures and analyzed by (1)H and (13)C 1D-2D NMR spectroscopy. Among the 15 compounds, ten have novel structures, although they possess some well-known structural patterns as blood group epitopes (Le(x), Le(y)) or other sequences already observed in other amphibia species. These results reinforce our hypothesis about the strict species-specificity of these carbohydrate chains. It must be noted that such species-specificity does not depend on one particular monosaccharide but it is rather due to a set of particular tri- or tetrasaccharide sequences. Hence, B. viridis species could be characterized by the simultaneous presence of a 2,3,6-trisubstituted galactosyl residue, the GlcNAc(beta 1-3)[Fuc(alpha 1-4)]GlcNAc beta sequence and the Le(x), Le(y) or Cad determinants. The anionic charge of the oligosaccharides is carried only by sialic acid alpha-(2-->6)-linked to GalNAc-ol residue as in Bufo bufo or in Bufo arenarum. PMID:11814443

Coppin, Alexandra; Maes, Emmanuel; Strecker, Gérard

2002-02-01

304

Effects of ultraviolet radiation on boreal toads in Colorado  

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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.

Corn, P. S.

1998-01-01

305

Rhabdias esculentarum n. sp. (Nematoda: Rhabdiasidae) from green frogs of the Rana esculenta species complex in Italy: molecular evidence, morphological description and genetic differentiation from its congeners in frogs and toads.  

Science.gov (United States)

A new taxon, Rhabdias esculentarum n. sp., is described based on DNA sequence analysis at multiple loci (i.e. mtDNA cox-1, 12S rRNA, ITS-1 and partial ITS-2 regions of the nuclear rDNA) and morphometric analysis carried out on specimens collected from the green frogs of the Rana esculenta species complex in Italy (i.e. R. lessonae Camerano and R. esculenta Linnaeus, identified genetically by diagnostic allozyme loci). Rhabdias esculentarum n. sp. was differentiated genetically, at both mitochondrial and nuclear levels, from Rh. bufonis (Schrank, 1788) (sensu Hartwich, 1972) and Rh. sphaerocephala Goodey, 1924 recovered from the toad Bufo bufo Linnaeus collected sympatrically with the specimens of Rana lessonae and R. esculenta examined in the present study. Moreover, the new taxon proved to be different from the other species of Rhabdias from anurans, which had previously been sequenced using the same genes and deposited in GeneBank. Phylogenetic analyses (MP and ML) inferred from mitochondrial (mtDNA cox-1 and 12S ribosomal RNA) and nuclear (ITS-1 and ITS-2 of the rDNA regions) sequences datasets were congruent in depicting Rh. esculentarum n. sp. as forming a highly supported clade distinct from the sympatric species Rh. bufonis, as well as from Rh. sphaerocephala, characterised on the basis of the same loci. Morphometric analysis and the differential diagnosis of genetically characterised specimens of the new species have revealed differences in several features in comparison with the type-species, Rh. bufonis. Material of the latter species included voucher specimens from Germany deposited by Hartwich (1972) and other specimens collected from B. bufo in Italy. Among the diagnostic characters, the particular cup-shaped buccal capsule characterising Rh. esculentarum is clearly different from the tear-shaped buccal capsule observed in material of R. bufonis obtained from Berlin Museum and collected in the same geographical area as the green frogs under study. Rh. esculentarum was also found to differ in some measurements and allometric characters from Rh. bufonis (sensu Moravec et al., 1997). The data so far collected appear to indicate a host-preference of Rh. esculentarum for Rana lessonae and R. esculenta, which belong to the R. esculenta hybridogenetic species complex in Italy. PMID:22581250

Cipriani, Paolo; Mattiucci, Simonetta; Paoletti, Michela; Santoro, Mario; Nascetti, Giuseppe

2012-06-01

306

A comparative study of melatonin production in the retina, pineal gland and harderian gland of Bufo viridis and Rana esculenta.  

Science.gov (United States)

1. The circadian patterns of melatonin and of its synthesizing enzyme N-acetyltransferase (NAT) were investigated in the serum, retina, pineal gland and Harderian gland (HG) of two amphibian species, Bufo viridis and Rana esculenta. 2. Serum melatonin levels showed no diurnal fluctuations in Bufo viridis, whereas, in Rana esculenta, they exhibited a circadian rhythm, with the highest values occurring during the night. Retina melatonin exhibited characteristic circadian patterns in both species, with the highest values occurring during the day, in Bufo, and the highest concentrations occurring at night in Rana. 3. In the retina, NAT activity peaked at night in both amphibians, but in Bufo the levels were up to 30 times higher than in Rana. In the HG and in the pineal gland, NAT activity showed different patterns in the two species with no diurnal variations in Bufo, and characteristic circadian rhythms in Rana. 4. In the HG and pineal gland of both species, melatonin was only occasionally detectable over the 24-hr period. 5. This is the first report exploring melatonin production in Bufo viridis and Rana esculenta. In our experimental conditions, marked differences emerged between the two species. PMID:7903612

Serino, I; d'Istria, M; Monteleone, P

1993-09-01

307

Substance P-like immunoreactivity in sympathetic ganglion from toad.  

Science.gov (United States)

Substance P-like immunoreactivity cellular in toad sympathetic ganglia was studied in normal and capsaicin-treated ganglia. In the eighth sympathetic ganglion substance P-like immunoreactive are found in mast cells and SIF cells. The effect of substance P (0.001-0.003 mM) caused increase of compound action potential during tetanical stimulation (50 Hz by 40 sec.) and post-tetanic potentiation (0.1 Hz). Our results show that substance P facilitates synaptic transmission in the sympathetic ganglia from Caudiverbera caudiverbera. PMID:2476215

Montoya, G A; Villena, F; Jofre, A; Pezo, A A

1989-01-01

308

2.MD Frog and Toad on the number line  

Science.gov (United States)

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

309

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

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

Carolina E. Rosenberg

2007-07-01

310

Antibacterial activity of lactose-binding lectins from Bufo arenarum skin  

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Full Text Available Amphibians respond to microbial infection through cellular and humoral defense mechanisms such as antimicrobial protein secretion. Most humoral defense proteins are synthetized in the skin. In this study we isolated two b-galactoside-binding lectins with molecular weights of 50 and 56 KDa from the skin of Bufo arenarum. These lectins have significant hemagglutination activity against trypsinized rabbit erythrocytes, which was inhibited by galactose-containing saccharides. They are water-soluble and independent of the presence of calcium. The antimicrobial analysis for each lectin was performed. At mmolar concentration lectins show strong bacteriostatic activity against Gram negative bacteria (Escherichia coli K12 4100 and wild strains of Escherichia coli and Proteus morganii and Gram positive bacteria (Enterococcus faecalis. The antibacterial activity of these lectins may provide an effective defense against invading microbes in the amphibian Bufo arenarum.

Alicia Sánchez Riera

2003-04-01

311

Antibacterial activity of lactose-binding lectins from Bufo arenarum skin  

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Full Text Available SciELO Argentina | Language: English Abstract in english Amphibians respond to microbial infection through cellular and humoral defense mechanisms such as antimicrobial protein secretion. Most humoral defense proteins are synthetized in the skin. In this study we isolated two b-galactoside-binding lectins with molecular weights of 50 and 56 KDa from the s [...] kin of Bufo arenarum. These lectins have significant hemagglutination activity against trypsinized rabbit erythrocytes, which was inhibited by galactose-containing saccharides. They are water-soluble and independent of the presence of calcium. The antimicrobial analysis for each lectin was performed. At mmolar concentration lectins show strong bacteriostatic activity against Gram negative bacteria (Escherichia coli K12 4100 and wild strains of Escherichia coli and Proteus morganii) and Gram positive bacteria (Enterococcus faecalis). The antibacterial activity of these lectins may provide an effective defense against invading microbes in the amphibian Bufo arenarum.

Alicia, Sánchez Riera; Adriana, Daud; Adriana, Gallo; Susana, Genta; Manuel, Aybar; Sara, Sánchez.

312

Lankesterella poeppigii n. sp. (Apicomplexa, Lankesterellidae from Bufo poeppigii (Tschudi, 1845 from Peru  

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Full Text Available Lankesterella poeppigii n. sp. is described from Bufo poeppigii (Tschudi, 1845 from Peru. Merogony and oogony occur in the capillary endothelium and the macrophages in the liver, spleen and kidneys. Meronts are oval, 25,2–29,4 x 15,7–16,8 ?m in size and yield 35–46 merozoites. Oocysts are 26,3–29,4 x 15,1–17,6 ?m in size; sporozoites 9,2-9,8 x 4,2–5,0 ?m in size, assemble in macrophages. Released 8,7–9,8 x 2,8–3,1 ?m sporozoites enter erythrocytes. L. poeppigii is compared with Lankesterella petiti Lainson & Paperna, 1995 infecting Bufo marinus (Linnaeus, 1758 in Brazil. The above mentioned specific characters, added to differences in hosts and geographical location warrant the description of Lankesterella poeppigii from B. poeppigii as a new species.

Ilan Paperna

2011-07-01

313

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

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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.

Muths, Erin; Scherer, Rick D.

2011-01-01

314

The antiepileptic drug phenytoin affects sodium transport in toad epithelium.  

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The effects of phenytoin on isolated Pleurodema thaul toad skin were investigated. Low (micromolar) concentrations of the antiepileptic agent applied to the outside surface of the toad epithelium increased the electrical parameters (short-circuit current and potential difference) by over 40%, reflecting stimulation of Na(+) transport, whereas higher (millimolar concentrations, outside and inside surface) decreased both electric parameters, the effect being greater at the inside surface (40% and 80% decrease, respectively). The amiloride test showed that the stimulatory effect was accompanied by an increase and the inhibitory effect by a decrease in the sodium electromotive force (ENa). It is concluded that the drug interaction with membrane lipid bilayers might result in a distortion of the lipid-protein interface contributing to disturbance of Na(+) epithelial channel activity. After applying the Na(+)-K(+)-ATPase blocker ouabain and replacing the Na(+) ions in the outer Ringer's solution by choline, it was concluded that both active and passive transport are involved in sodium absorption, although active transport predominates. PMID:16314149

Suwalsky, Mario; Mennickent, Sigrid; Norris, Beryl; Cárdenas, Hernan

2006-01-01

315

Toad in the hole : Suncor finds amphibious life at tailings ponds  

Energy Technology Data Exchange (ETDEWEB)

Suncor, a giant oilsands operator, has discovered Canadian toads in five of its nine tailings ponds surveyed in 2002. The numbers are greater than any recorded in the boreal forests. Most are living in a dike along the company's oldest tailings pond which include slurries of sand, water, clay, residual bitumen and chemicals left from oilsands production. Reclamation efforts have involved emptying the tailings and filling the area with sand to create a combination of wet and dry lands. The presence of Canadian toads is a good indicator of environmental health. In the late 1990s, the species was among those listed at risk of declining levels. It is believed that the sandy soil layers in the reclamation ponds are ideal for toad hibernation. Suncor and Golder and Associations are currently examining the feasibility of having the reclaimed areas become future restorations of toad habitat.

Jaremko, D.

2004-08-02

316

All-optical multibit address recognition at 20 Gb/s based on TOAD  

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All-optical multibit address recognition at 20 Gb/s is demonstrated based on a special AND logic of terahertz optical asymmetric demultiplexer (TOAD). The semiconductor optical amplifier (SOA) used in the TOAD is biased at transparency status to accelerate the gain recovery. This is the highest bit rate that multibit address recognition is demonstrated with SOA-based interferometer. The experimental results show low pattern dependency. With this method, address recognition can be performed without separating address and payload beforehand.

Yan, Yumei; Wu, Jian; Lin, Jintong

2005-04-01

317

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

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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

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

2014-09-30

318

Descripción de dos renacuajos y una clave para las larvas conocidas del grupo Bufo spinulosus (Anura: Bufonidae de Perú  

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Full Text Available Se describen los renacuajos de Bufo arequipensis y Bufo cophotis. Ningún carácter externo examinado permite distinguir la larva de las especies nominales B. arequipensis, B. flavolineatus y B. trifolium. La larva de Bufo limensis se diferencia de las de B. flavolineatus y B. trifolium por presentar un espacio menor en la segunda fila anterior de dentículos labiales y una fórmula de dentículos labiales (LTRF igual a 2(2/3[1]. B. cophotis difiere de B. limensis, B. flavolineatus y B. trifolium por presentar la altura máxima de la cola en su extremo posterior, una coloración marrón oscura en el cuerpo y cola, y un LTRF igual a 2(2/3(1. Se proporciona una clave de identificación para las larvas conocidas del grupo spinulosus presentes en Perú.

César Aguilar

2013-06-01

319

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

International Nuclear Information System (INIS)

emoved 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

320

Target of Opportunity Observations of TOADS: Finding the Dust in Super-Outburst Ejecta  

Science.gov (United States)

Tremendous Outburst Amplitude Dwarf novae (TOADs) consist of a white dwarf primary star and an extremely low mass main sequence or brown dwarf-like secondary star. The latter fills its Roche lobe and transfers matter to the white dwarf through the inner Lagrange point into an accretion disk. TOADs undergo non-thermonuclear (i.e., disk instability) super-outbursts on timescales of decades. During the decline from super-outburst peak they display a characteristic dip in light curves at visible wavelengths, reminiscent of what is observed in slow classical (i.e., thermonuclear runaway) novae. In classical novae, the visible light dip is attributed to the formation of dust in the nova ejecta but, until now, the cause of the dip in TOAD light curves has remained unclear. In 2004, a previously unknown TOAD was discovered as it went into super-outburst, and our team was granted a Spitzer DDT program with which we have detected the likely formation of dust in the outburst ejecta. We now propose a Target of Opportunity program with Spitzer to observe an additional super-outbursting TOAD, in order to address the following questions: 1) Do all TOADs produce dust during their outbursts?; 2) What is the timescale for dust formation and dissipation?; 3) How much dust is produced during a super-outburst?; and 4) How does the dust production scale with the outburst amplitude? Spitzer is uniquely capable of detecting and characterizing the dust formed in the ejecta during super-outbursts and fundamentally changing the understanding of TOADs, their super-outbursts, and their contribution to the recycling of the interstellar medium.

Hoard, Donald; Ciardi, David; Howell, Steve

2008-03-01

 
 
 
 
321

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

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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

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

2013-10-15

322

77 FR 6815 - Emergency Exemption; Issuance of Emergency Permit To Salvage Houston Toads Affected by a Wildfire...  

Science.gov (United States)

...acres burned in Bastrop County, Texas, much of which was habitat for the endangered Houston toad. The Houston toad usually emerges...captive breeding or captive assurance colony at the Houston Zoo. Authority: 16 U.S.C. 1531 et seq. Dated:...

2012-02-09

323

The effects of the toxic cyanobacterium Limnothrix (strain AC0243) on Bufo marinus larvae.  

Science.gov (United States)

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

Daniels, Olivia; Fabbro, Larelle; Makiela, Sandrine

2014-03-01

324

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

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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 ?-N-Methylamino-L-alanine are discussed.

Olivia Daniels

2014-03-01

325

African clawed toads (Xenopus laevis) sense the distance of lateral line stimuli.  

Science.gov (United States)

Sighted African clawed toads use their lateral lines to detect stimulus distance, although accuracy and precision are poorer than for stimulus direction. Single surface wave trains elicited discrete turns and/or swims towards the wave origin. Most responses were brief, ending with the toad stationary (70% overall; 54-86% individual toads) or pausing before turning away (11%; 1-24%). Lunges or capturing movements with the arms (13%; 10-22%) also indicated where toads expected to find prey. Overall, 94% (88-100%) of oriented responses had well-defined endpoints. Swim distance--measured as means, medians, and upper and lower quartiles--and the number of bilateral leg kicks increased with stimulus distance. Swim distance also depended upon stimulus angle due to features of turning. Most responses (81%; 62-92%) ended short of the wave origin. Regression slopes were 0.45 ± 0.04 mm/mm for stimulus distances up to 85 mm (ca. 2-3x body lengths), 0.16 ± 0.07 mm/mm for distances of 85-130 mm, and non-significant for larger distances to 220 mm. Slopes were steeper for responses that included lunges or capture movements. In only 15% (3-26%) of responses were both turn direction and swim distance sufficiently accurate for the toad to sweep through the wave origin. PMID:24781249

Dean, Jeffrey; Claas, Barbara

2014-07-01

326

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

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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.

N.E. Abdelmeguid

2000-01-01

327

Effect of forskolin on conductive anion pathways of toad skin.  

Science.gov (United States)

The effect of the diterpene, forskolin, on pathways for conductive Cl- transport was analyzed using isolated skins of Bufo viridis. Forskolin did not stimulate the voltage-activated Cl- movement from mucosa to serosa; the Lorentzian component in the power density spectrum, which was present at serosa positive clamp potentials under control conditions, decreased significantly. The observation that stimulation of cytosolic adenosine 3'-5'-cyclic monophosphate (cAMP) by forskolin has no effect on the voltage-activated Cl- transport argues against control of this pathway by cAMP. Our data further demonstrate that the forskolin-activated Cl- conductive pathway is also permeable for NO3-. This pathway was studied in absence of mucosal Cl-, which eliminates Cl- movement through the voltage-activated pathway. With SO4(2-) and Cl- on the mucosal and serosal sides, respectively, this forskolin-induced pathway displayed a linear current-voltage relationship. The associated Lorentzians increased at serosa negative clamp potentials. Transepithelial current and plateau value of the Lorentzian were related by a quadratic function, which suggests voltage-independence of number and open-close probability of these conductance sites. Morphological sites for voltage-activated and forskolin-induced conductive Cl- transport remain to be identified. PMID:1636675

Nagel, W; Van Driessche, W

1992-07-01

328

Contribution to the study of immune hemolysis by toad complement  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese EA (eritrócitos de carneiro, sensibilizados com anticorpos de coelho) são lisados por complemento de sapo em condições ótimas, que consistem no uso de uma baixa concentração de células (1.54 x 10*8/ml), incubação a baixa temperatura (30°C) e as mesmas quantidades de Ca++ e de Mg++, requeridas para a [...] titulação da atividade hemolítica do complemento de cobaia. Estudos cinéticos do efeito dos cátions mencionados acima na imune-lise produzida pelo complemento de sapo revelam uma diferença fundamental com relação ao complemento de cobaía. Num sistema limitado pela quantidade de complemento, a lise pelo C de anfíbio é totalmente bloqueada por EDTA, mesmo quando a adição do agente quelante é feita após 15 minutos, ao passo que com EGTA o bloqueio é apenas parcial. Os achados experimentais sugerem que Mg++ seja requerido não apenas no estágio inicial, mas também em estágios tardios do processo lítico e permitem especular que a ativação do complemento de anfíbio se processa predominantemente pela via alternativa. Abstract in english EA (sheep erythrocytes carrying rabbit antibody) are lysed by toad complement under optimal conditions which include a low concentration of cells (1.54 x 10*8/ml), a low temperature of incubation (30°C) and the same amounts of Ca++ and Mg++ as required for the titration of guinea-pig complement. Kin [...] etic studies of the role of cations mentioned above in immune lysis by toad C have disclosed a fundamental difference as compared to guinea-pig C. In a limited complement system, the lysis by amphibian C is completely blocked by EDTA, even when the chelating agent is added as late as 15 minutes after zero-time. Inhibition by EGTA is only partial and the findings suggest that Mg++ is required not only at the beginning, but also at late stages of the lytic process. It has been speculated that the activation of amphibian complement proceeds mainly by the alternative pathway.

Marisa, Gennari; Moema H., Reis; Vera C. A., Ferreira; Maria, Siqueira; Otto G., Bier.

1982-09-01

329

Characterisation of major histocompatibility complex class I in the Australian cane toad, Rhinella marina.  

Science.gov (United States)

The Major Histocompatibility Complex (MHC) class I is a highly variable gene family that encodes cell-surface receptors vital for recognition of intracellular pathogens and initiation of immune responses. The MHC class I has yet to be characterised in bufonid toads (Order: Anura; Suborder: Neobatrachia; Family: Bufonidae), a large and diverse family of anurans. Here we describe the characterisation of a classical MHC class I gene in the Australian cane toad, Rhinella marina. From 25 individuals sampled from the Australian population, we found only 3 alleles at this classical class I locus. We also found large number of class I alpha 1 alleles, implying an expansion of class I loci in this species. The low classical class I genetic diversity is likely the result of repeated bottleneck events, which arose as a result of the cane toad's complex history of introductions as a biocontrol agent and its subsequent invasion across Australia. PMID:25093458

Lillie, Mette; Shine, Richard; Belov, Katherine

2014-01-01

330

20Gbit/s all-optical logic OR in terahertz optical asymmetric demultiplexer (TOAD)  

Science.gov (United States)

A scheme for all-optical logic OR based on transparent teraherz optical asymmetric demultiplexer (transparent-TOAD) is proposed in this paper. In the transparent-TOAD, the SOA is biased at transparency and the gain recovery time determined by the intraband effect has the value of only a few picoseconds. Numerical analysis shows that the switching window of the transparent-TOAD is only about 0.54ps and the potential for ultrahigh speed all-optical logic processing is shown. Numerical demonstration is performed for 4-bit and 16-bit logic OR at 20Gbit/s. The results coincide with the OR truth table, showing high extinction ratio and no pattern dependency. Detailed analysis is carried out on the performance of the logic OR scheme.

Yan, Yumei; Wu, Jian; Lin, Jintong

2005-01-01

331

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

Scientific Electronic Library Online (English)

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

César, Aguilar; Rocío, Gamarra.

2004-07-01

332

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

Scientific Electronic Library Online (English)

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

César, Aguilar; Rocío, Gamarra.

333

Ultrastructural study of the lateral line neuromasts in tadpoles of Saudi Bufo dhufarensis and Rana ridibunda.  

Science.gov (United States)

Neuromast (hair cells) structure in Bufo dhufarensis and Rana ridibunda larvae was observed by Scanning Electron Microscopy (SEM). Neuromasts were found arranged in one well-defined line in the head, body, and tail regions forming the lateral line and also found haphazardly scattered in most of the body parts. Their number was significantly high in the head region, and then it gradually decreased along the posterior end of the body. The structure of neuromasts in these three regions was basically similar for each species. In Rana, neuromasts were found few in number, either spherical or oval in shape lacking hair-like structure except in the tail region where hair cells were found. While in Bufo, neuromasts were numerous. Long kinocilia and many stereocilia were found in the neuromasts. Kinocilia were either solitary or in clusters. In addition to the main functions of the neuromasts we discovered a new function which was not found in previous researches, neuromasts were also used to remove any attached object on the tadpole's skin, by directing the kinocilium to the object thing and rolling onto it then detaching it outwards. PMID:24961010

Fahmy, Gehan H; Bekhet, Gamal A

2014-04-01

334

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

Scientific Electronic Library Online (English)

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

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

2006-08-01

335

The antiepileptic drug carbamazepine affects sodium transport in toad epithelium.  

Science.gov (United States)

The present work investigates the effects of the antiepileptic drug carbamazepine (CBZ) on sodium transport in the isolated skin of the toad Pleurodema thaul. A submaximal concentration of the drug (0.2 mM) applied to the outer surface of the epithelium increased the electrical parameters short-circuit current (Isc) and potential difference (PD) by over 28%, whereas only a higher concentration (1 mM) induced over a 45% decrease in these parameters when applied to the inner surface. The amiloride test showed that the outer surface stimulatory effect was accompanied by an increase and the inner surface inhibitory effect by a decrease in the sodium electromotive force (ENa). Exploration of these effects of CBZ on the outer surface showed that 0.2 mM increased net Na+ (22Na) influx by 20% and 0.6 mM CBZ decreased Na+ mucosa-serosa flux by 19%, a result in agreement with the finding that higher concentrations of CBZ applied to the inner surface not only decreased ENa but also sodium conductance (GNa). PMID:16542818

Suwalsky, Mario; Mennickent, Sigrid; Norris, Beryl; Cardenas, Hernán

2006-09-01

336

High repetition rate optical switch using an electroabsorption modulator in TOAD configuration  

Science.gov (United States)

A novel optical switch featured with high repetition rate, short switching window width, and high contrast ratio is proposed and demonstrated for the first time by placing an electroabsorption modulator (EAM) in a terahertz optical asymmetric demultiplexer (TOAD) configuration. The feasibility and main characteristics of the switch are investigated by numerical simulations and experiments. With this EAM-based TOAD, an error-free return-to-zero signal wavelength conversion with 0.62 dB power penalty at 20 Gbit/s is demonstrated.

Huo, Li; Yang, Yanfu; Lou, Caiyun; Gao, Yizhi

2007-07-01

337

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

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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 remain...

Nirmal Sukul; Arniban Sukul; Indrani Chakraborty

2012-01-01

338

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

Scientific Electronic Library Online (English)

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

Marco A., Méndez; Eduardo R., Soto; Claudio, Correa; Alberto, Veloso; Eliseo, Vergara; Michel, Sallaberry; Patricia, Iturra.

339

Time-dependent aldosterone metabolism in toad urinary bladder  

Energy Technology Data Exchange (ETDEWEB)

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

Brem, A.S.; Pacholski, M.; Morris, D.J.

1988-04-01

340

Components of Sodium and Chloride Flux Across Toad Bladder  

Science.gov (United States)

The effect of transepithelial potential difference (?) on Na and Cl flux across toad bladder was assessed by measuring isotopic flux between identical media at various values of ?. The contribution of edge damage to ionic permeability was eliminated, resulting in relatively high spontaneous ? (-97 ±4 mv) and low electrical conductance g. Bidirectional Na fluxes were measured simultaneously. Unidirectional Cl fluxes were measured in paired hemibladders at ? = 0 mv or -97 mv. Net Na flux JNa, at ? = 0 mv, was slightly less than short-circuit current (SCC). At ? = -97 mv, JNa averaged 17% of SCC, and was sometimes zero. ?JNa/?? (= g+) averaged 60% of g between -97 mv and +75 mv; at -150 mv, g+ fell, indicating rectification. Analysis of unidirectional Na fluxes indicates low passive conductance (1.5 ?mho/mg wet weight), a bidirectional, electrically neutral flux of approximately 0.13 ?a/mg, and relatively large conductance of the active transport path at ? ? -97 mv. The absence of appreciable transstimulation of serosal (S)-to-mucosal (M) Na flux (in response to increasing mucosal Na concentration) indicates that the electrically neutral flux is not exchange diffusion in the usual sense. Analysis of Cl fluxes indicates similar values for passive conductance and neutral flux, suggesting linked neutral flux of Na and Cl. Either the electromotive force of the Na pump E, its conductance ga, or both are strong functions of ?. The product of these two quantities, Ega, is a measure of the “transport capacity” at any given value of ?, independent of the direct effect of ? on JNa through the pump path. Ega varies with ?. Hence estimation of the net Na flux or current at any one value of ?, including ? = 0, fails to reveal the maximal transport capacity of the pump, its resting electromotive force (when JNa = 0 through the pump), or the dependence of transport capacity on potential. PMID:4623090

Walser, Mackenzie

1972-01-01

 
 
 
 
341

Time-dependent aldosterone metabolism in toad urinary bladder  

International Nuclear Information System (INIS)

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

342

Alkaloids from bufonid toads (Melanophryniscus): decahydroquinolines, pumiliotoxins and homopumiliotoxins, indolizidines, pyrrolizidines, and quinolizidines.  

Science.gov (United States)

Skins of bufonid toads of the genus Melanophryniscus contain several classes of alkaloids: decahydroquinolines, pumiliotoxins, allopumiliotoxins, homopumiliotoxins, both 3,5- and 5,8-disubstituted indolizidines, 3,5-disubstituted pyrrolizidines, and a 1,4-disubstituted quinolizidine. Tricyclic alkaloids, including precoccinelline [193A] and alkaloid 236, an oxime methyl ether, are present in one population of Melanophryniscus stelzneri. PMID:8482947

Garraffo, H M; Spande, T F; Daly, J W; Baldessari, A; Gros, E G

1993-03-01

343

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

Science.gov (United States)

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. Environ Toxicol Chem 2014;33:2541-2544. © 2014 SETAC. PMID:25099070

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

2014-11-01

344

Effect of parathyroid hormone on transport by toad and turtle bladder  

International Nuclear Information System (INIS)

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

345

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

Science.gov (United States)

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

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

346

Immune response varies with rate of dispersal in invasive cane toads (Rhinella marina).  

Science.gov (United States)

What level of immunocompetence should an animal maintain while undertaking long-distance dispersal? Immune function (surveillance and response) might be down-regulated during prolonged physical exertion due to energy depletion, and/or to avoid autoimmune reactions arising from damaged tissue. On the other hand, heightened immune vigilance might be favored if the organism encounters novel pathogens as it enters novel environments. We assessed the links between immune defense and long-distance movement in a population of invasive cane toads (Rhinella marina) in Australia. Toads were radio-tracked for seven days to measure their activity levels and were then captured and subjected to a suite of immune assays. Toads that moved further showed decreased bacteria-killing ability in their plasma and decreased phagocytic activity in their whole blood, but a heightened skin-swelling response to phytohemagglutinin. Baseline and post-stress corticosterone levels were unrelated to distance moved. Thus, long-distance movement in cane toads is associated with a dampened response in some systems and enhanced response in another. This pattern suggests that sustained activity is accompanied by trade-offs among immune components rather than an overall down or up-regulation. The finding that high mobility is accompanied by modification of the immune system has important implications for animal invasions. PMID:24936876

Brown, Gregory P; Shine, Richard

2014-01-01

347

The arsenic action during the Bufo arenarum gonad development (Anura: Bufonidae  

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Full Text Available Bufo arenarum ovulations have been kept in potassium bibasic arsenate from the fertilization until 26mm larva. The gonad in development, in the presence of the toxic, suffers significant alterations in its volume, shape and structure. It does not have the typical naillike morphology; on the other hand, it is presented as a spherical mass of reduced volume, that has, as demostrated by the histological analysis, very few oocytes or gonia submerged in a very scarce quantity of stroma. The hypothesis of this study was that it would be due to a succession of events whose cause would lie on the damage that the arsenic determine at the somatic layers level.

Rengel, Dora

1991-01-01

348

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

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

Rappi, Guillermina E.

2000-04-01

349

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

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

Cristina Silvia Pérez-Coll

2007-06-01

350

Ion transport by mitochondria-rich cells in toad skin  

DEFF Research Database (Denmark)

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

Larsen, Erik Hviid; Ussing, H H

1987-01-01

351

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

International Nuclear Information System (INIS)

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

352

Frogs and toads in front of a mirror: lateralisation of response to social stimuli in tadpoles of five anuran species.  

Science.gov (United States)

Tadpoles of five anuran species were tested for preferences in the use of the eyes during inspection of their own visual image in a mirror. When tested in a tank with several small mirrors, tadpoles of five different species (Bufo bufo, Bufo viridis, Rana temporaria, Rana esculenta, Bombina variegata) preferentially approached and positioned themselves with the mirror located on their left side, thus looking at the image with the monocular field of their left eye. Similar results were obtained with tadpoles of R. temporaria tested in a simple task in which they had to choose approaching one or other of two large mirrors located on their left and right side. Control experiment showed that the behavioural asymmetry was not due to motor preferences and that it was independent of morphological asymmetries in the positions of the spiracles. This is the first demonstration of a functional visual lateralisation among juvenile amphibia before metamorphosis. PMID:12191829

Bisazza, Angelo; De Santi, Andrea; Bonso, Silvia; Sovrano, Valeria Anna

2002-08-21

353

78 FR 31973 - Endangered and Threatened Species Permit Applications  

Science.gov (United States)

... Houston toad (Bufo houstonensis) Ocelot (Leopardus pardalis) Southwestern willow flycatcher (Empidonax...jaguarundi (Herpailurus yagouaroundi), and ocelot (Leopardus pardalis) within Pima County, Tohono O'odham...

2013-05-28

354

Indolizidine 239Q and quinolizidine 275I. Major alkaloids in two Argentinian bufonid toads (Melanophryniscus).  

Science.gov (United States)

Alkaloid profiles in skin of poison frogs/toads (Dendrobatidae, Mantellidae, Bufonidae, and Myobatrachidae) are highly dependent on diet and hence on the nature of habitat. Extracts of the two species of toads (Melanophryniscus klappenbachi and Melanophryniscus cupreuscapularis) from similar habitats in the Corrientes/Chaco Provinces of Argentina have similar profiles of alkaloids, which differ considerably in profiles from other Melanophryniscus species from Brazil, Uruguay and Argentina. Structures of two major alkaloids 239Q (1) and 275I (2) were determined by mass, FTIR, and NMR spectral analysis as 5Z,9Z-3-(1-hydroxybutyl)-5-propylindolizidine and 6Z,10E-4,6-di(pent-4-enyl) quinolizidine, respectively. A third alkaloid, 249F (3), is postulated to be a homopumiliotoxin with an unprecedented conjugated exocyclic diene moiety. PMID:18848574

Daly, John W; Garraffo, H Martin; Spande, Thomas F; Yeh, Herman J C; Peltzer, Paola M; Cacivio, Pedro M; Baldo, J Diego; Faivovich, Julián

2008-12-15

355

Using spatiotemporal models and distance sampling to map the space use and abundance of newly metamorphosed Western Toads (Anaxyrus boreas)  

Science.gov (United States)

High variability in abundance, cryptic coloration, and small body size of newly metamorphosed anurans have limited demographic studies of this life-history stage. We used line-transect distance sampling and Bayesian methods to estimate the abundance and spatial distribution of newly metamorphosed Western Toads (Anaxyrus boreas) in terrestrial habitat surrounding a montane lake in central Washington, USA. We completed 154 line-transect surveys from the commencement of metamorphosis (15 September 2009) to the date of first snow accumulation in fall (1 October 2009), and located 543 newly metamorphosed toads. After accounting for variable detection probability associated with the extent of barren habitats, estimates of total surface abundance ranged from a posterior median of 3,880 (95% credible intervals from 2,235 to 12,600) in the first week of sampling to 12,150 (5,543 to 51,670) during the second week of sampling. Numbers of newly metamorphosed toads dropped quickly with increasing distance from the lakeshore in a pattern that differed over the three weeks of the study and contradicted our original hypotheses. Though we hypothesized that the spatial distribution of toads would initially be concentrated near the lake shore and then spread outward from the lake over time, we observed the opposite. Ninety-five percent of individuals occurred within 20, 16, and 15 m of shore during weeks one, two, and three respectively, probably reflecting continued emergence of newly metamorphosed toads from the lake and mortality or burrow use of dispersed individuals. Numbers of toads were highest near the inlet stream of the lake. Distance sampling may provide a useful method for estimating the surface abundance of newly metamorphosed toads and relating their space use to landscape variables despite uncertain and variable probability of detection. We discuss means of improving the precision of estimates of total abundance.

Chelgren, Nathan D.; Samora, Barbara; Adams, Michael J.; McCreary, Brome

2011-01-01

356

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

Science.gov (United States)

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.

Chattopadhyay, Tanay

357

Reduce torques and stick the landing: limb posture during landing in toads.  

Science.gov (United States)

A controlled landing, where an animal does not crash or topple, requires enough stability to allow muscles to effectively dissipate mechanical energy. Toads (Rhinella marina) are exemplary models for understanding the mechanics and motor control of landing given their ability to land consistently during bouts of continuous hopping. Previous studies in anurans have shown that ground reaction forces (GRFs) during landing are significantly higher compared with takeoff and can potentially impart large torques about the center of mass (COM), destabilizing the body at impact. We predict that in order to minimize such torques, toads will align their COM with the GRF vector during the aerial phase in anticipation of impact. We combined high-speed videography and force-plate ergometry to quantify torques at the COM and relate the magnitude of torques to limb posture at impact. We show that modulation of hindlimb posture can shift the position of the COM by about 20% of snout-vent length. Rapid hindlimb flexion during the aerial phase of a hop moved the COM anteriorly and reduced torque by aligning the COM with the GRF vector. We found that the addition of extrinsic loads did not significantly alter landing behavior but did change the torques experienced at impact. We conclude that anticipatory hindlimb flexion during the aerial phase of a hop is a critical feature of a mechanically stable landing that allows toads to quickly string together multiple, continuous hops. PMID:25320271

Azizi, Emanuel; Larson, Neil P; Abbott, Emily M; Danos, Nicole

2014-10-15

358

Calcineurin regulates progressive motility activation of Rhinella (Bufo) arenarum sperm through dephosphorylation of PKC substrates.  

Science.gov (United States)

Animals with external fertilization, as amphibians, store their sperm in a quiescent state in the testis. When spermatozoa are released into natural fertilization media, the hypotonic shock triggers activation of sperm motility. Rhinella (Bufo) arenarum sperm are immotile in artificial seminal plasma (ASP, resembling testicular plasma tonicity) but acquire in situ flagellar beating upon dilution. However, if components from the egg shelly coat are added to this medium, motility shifts to a progressive pattern. Recently, we have shown that the signal transduction pathway required for in situ motility activation involves a rise in intracellular cAMP through a transmembrane adenylyl cyclase and activation of PKA, mostly in the midpiece and in the sperm head. In this report, we demonstrate that activation of calcineurin (aka PP2B and PPP3) is required for the shift from in situ to progressive sperm motility. The effect of calcineurin is manifested by dephosphorylation of PKC substrates, and can be promoted by intracellular calcium rise by Ca(2+) ionophore. Both phosphorylated PKC substrates and calcineurin localized to the flagella, indicating a clear differentiation between compartmentalization of PKA and calcineurin pathways. Moreover, no crosstalk is observed between these signaling events, even though both pathways are required for progressive motility acquisition as discussed. PMID:24648036

Krapf, Dario; O'Brien, Emma; Maidagán, Paula M; Morales, Enrique S; Visconti, Pablo E; Arranz, Silvia E

2014-10-01

359

[Bufo gargarizans mcl-1 cloning and its prokaryotic recombinant protein expression].  

Science.gov (United States)

MCL-1 is encoded by myeloid cell leukemia-1 gene (mcl-1), which is one of the anti-apoptotic members of bcl-2 cell apoptotic gene superfamily. ChanSu is made of dorsal secretions of several Bufo species, commonly used in the prescriptions of traditional Chinese medicine for treating many diseases including cancer. To clarify if mcl-1 is expressed in the dorsal skin of B. gargarizans, the PCR (polymerase chain reaction) was performed with its dorsal skin first strand cDNA as the template and a pair of specific primers of mcl-1, and PCR products were cloned into the pGM-T vector. DNA sequencing indicated that the ORF length was 639 bp encoding 212 amino acid residues, and the homology of 44%-95% with the MCL-1 of several other animals. For the further studies on MCL-1 biological functions during the oncogenesis and preparation of its antibody, the prokaryotic expression construct of pET-28b-mcl-1 was prepared which was confirmed by DNA sequencing, and its recombinant protein expression (0.02% wet weight) in E. coli BL21 (DE3) strain was confirmed by SDS-PAGE and Western blotting. PMID:24417092

Hu, Qiao-Ling; Zhang, Shu-Fang; Yang, Xian-Yu; Yu, Mei-Hua; Zhu-Ge, Hui

2013-10-01

360

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

Directory of Open Access Journals (Sweden)

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

O. Fridman

2006-03-01

 
 
 
 
361

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

Energy Technology Data Exchange (ETDEWEB)

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.

Yuracko, K L; Parang, M; Landguth, D C; Coleman, R

2004-09-13

362

Studies on the poisonous skin secretion of individual red bellied toads, Melanophryniscus montevidensis (Anura, Bufonidae), from Uruguay.  

Science.gov (United States)

Toads belonging to the genus Melanophryniscus contain toxic alkaloids in their skin. From six locations in south-eastern Uruguay 81 specimens of Melanophryniscusmontevidensis were collected. In whole animal methanolic extracts of individual specimens, alkaloids of the pumiliotoxin (PTX) group and indolizidines were identified by gas chromatography/mass spectrometry; the predominant component PTX 251D was assayed quantitatively. The PTX-content of the various toad populations was found to be highly variable among individual specimens as well as among the populations. Very high levels of PTX 251D were detected in toads of the western part of the collection area, whereas very low levels of this alkaloid were assayed in toads near the Brazilian border. Remarkably high concentrations of the non-alkaloid hydroquinone were found to be present in all toads. The analysis of extracts from 125 arthropod samples (Arachnida and Insecta, including termites, ants and beetles), which may represent a potential food source, revealed no alkaloids of the PTX group. PMID:16157358

Mebs, Dietrich; Pogoda, Werner; Maneyro, Raul; Kwet, Axel

2005-11-01

363

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

Science.gov (United States)

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

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

2014-01-01

364

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

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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.

H. Abdel-Latif

1999-01-01

365

The straight and narrow path: the evolution of straight-line dispersal at a cane toad invasion front.  

Science.gov (United States)

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 exhibit straighter paths than those following behind. Our studies on invasive cane toads (Rhinella marina) in tropical Australia clearly support this prediction. Radio-tracking of field-collected toads at a single site showed that path straightness steadily decreased over the first 10 years post-invasion. Consistent with an evolved (genetic) basis to that behavioural shift, path straightness of toads reared under common garden conditions varied according to the location of their parents' origin. Offspring produced by toads from the invasion vanguard followed straighter paths than did those produced by parents from long-established populations. At the individual level, offspring exhibited similar path straightness to their parents. The dramatic acceleration of the cane toad invasion through tropical Australia has been driven, in part, by the evolution of a behavioural tendency towards dispersing in a straight line. PMID:25297862

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

2014-11-22

366

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

Scientific Electronic Library Online (English)

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

Lucila, Venturini.

367

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

Directory of Open Access Journals (Sweden)

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..

Lucila Venturini

1989-10-01

368

Notes on the biology of Amblyomma dissimile Kock, 1844 (Acari: Ixodida) on Bufo marinus (Linnaeus, 1758) from Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Amblyomma dissimile is a common ectoparasite of cold blooded animals and is an accidental ectoparasite of some wild mammals. Details of the biology of specimens from the State of Amapá were studied in the laboratory in a humidity chamber at an average environmental temperature of 19.5 °C, using Bufo [...] marinus as host for the time in Brazil. We also report the first record of this species in the State of Minas Gerais.

Teresinha Tizu Sato, Schumaker; Darci Moraes, Barros.