WorldWideScience

Sample records for bufonid toads melanophryniscus

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

    Science.gov (United States)

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

    2008-01-01

    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 M. cupreuscapularis) from similar habitats in the Corrientes/Chaco Provinces of Argentina have similar profiles of alkaloids, which differ considerably from 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

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

    Science.gov (United States)

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

    2007-01-01

    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.

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

    Science.gov (United States)

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

    2016-05-01

    Toad glandular secretions and skin extractions contain numerous natural agents which may provide unique resources for novel drug development. Especially the skin-parotoid gland secretions of toads from genus Bufo contain as many as 86 different types of active compounds, each with the potential of becoming a potent drug. In the present study, crude skin-parotoid gland secretions from Bufo bufo, Bufo verrucosissimus and Bufotes variabilis from Turkey were screened against various cancer cells together with normal cells using MTT assay. Furthermore, the antimicrobial properties of skin secretions were tested on selected bacterial and fungal species for assessing the possible medical applications. Antimicrobial activity of skin secretions was studied by determining minimal inhibitory concentration (MIC) in broth dilution method. Hemolytic activity of each skin-secretion was also estimated for evaluating pharmaceutical potential. Both skin-parotoid gland secretions showed high cytotoxic effect on all cancerous and non-cancerous cell lines with IC50 values varying between <0.1μg/ml and 6.02μg/ml. MIC results of antimicrobial activity tests were found to be between 3.9μg/ml and 250μg/ml. No hemolytic activities on rabbit red blood cells at concentrations between 0.5μg/ml and 50μg/ml were observed. In conclusion, skin-parotoid secretions of bufonid toads might be remarkable candidates for anti-cancer and antimicrobial agents without hemolytic activities. Copyright © 2016. Published by Elsevier Masson SAS.

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

    Science.gov (United States)

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

    2005-11-01

    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.

  5. Variation of thermal parameters in two different color morphs of a diurnal poison toad, Melanophryniscus rubriventris (Anura: Bufonidae).

    Science.gov (United States)

    Sanabria, Eduardo A; Vaira, Marcos; Quiroga, Lorena B; Akmentins, Mauricio S; Pereyra, Laura C

    2014-04-01

    We study the variation in thermal parameters in two contrasting populations Yungas Redbelly Toads (Melanophryniscus rubriventris) with different discrete color phenotypes comparing field body temperatures, critical thermal maximum and heating rates. We found significant differences in field body temperatures of the different morphs. Temperatures were higher in toads with a high extent of dorsal melanization. No variation was registered in operative temperatures between the study locations at the moment of capture and processing. Critical thermal maximum of toads was positively related with the extent of dorsal melanization. Furthermore, we founded significant differences in heating rates between morphs, where individuals with a high extent of dorsal melanization showed greater heating rates than toads with lower dorsal melanization. The color pattern-thermal parameter relationship observed may influence the activity patterns and body size of individuals. Body temperature is a modulator of physiological and behavioral functions in amphibians, influencing daily and seasonal activity, locomotor performance, digestion rate and growth rate. It is possible that some growth constraints may arise due to the relationship of color pattern-metabolism allowing different morphs to attain similar sizes at different locations instead of body-size clines. Copyright © 2014. Published by Elsevier Ltd.

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

    Science.gov (United States)

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

    2012-12-01

    GC-MS analysis of single-skins of ten Melanophryniscus rubriventris toads (five collections of two toads each) captured during their breeding season in NW Argentina has revealed a total of 127 alkaloids of which 56 had not been previously detected in any frog or toad. Included among these new alkaloids are 23 new diastereomers of previously reported alkaloids. What is particularly distinguishing about the alkaloid profiles of these ten collections is the occurrence of many of the alkaloids, whether known or new to us, in only one of the ten skins sampled, despite two skins being obtained from each breeding site of the five populations. Many of the alkaloids are of classes known to have structures with branched-chains (e.g. pumiliotoxins and tricyclic structures) that are considered to derive from dietary mites. A large number of previously reported and new alkaloids are also of unclassified structures. Only a very few 3,5-disubstituted-indolizidine or -pyrrolizidine alkaloids are observed that have a straight-chain carbon skeleton and are likely derived from ant prey. The possible relationship of these collections made during the toad's brief breeding episodes to sequestration of dietary arthropods and individual alkaloid profiles is discussed.

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

    Science.gov (United States)

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

    2014-11-01

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

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

    Science.gov (United States)

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

    2009-08-23

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

  9. Phylogenetic relationships of diurnal, phytotelm-breeding Melanophryniscus (Anura: Bufonidae) based on mitogenomic data.

    Science.gov (United States)

    Pie, Marcio R; Ströher, Patrícia R; Belmonte-Lopes, Ricardo; Bornschein, Marcos R; Ribeiro, Luiz F; Faircloth, Brant C; McCormack, John E

    2017-09-10

    Melanophryniscus is a bufonid frog genus with a broad geographic distribution over southeastern South America. In recent years, several new species of Melanophryniscus have been discovered in southern Brazil showing a distinctive life-history strategy for the genus - breeding in phytotelmata - as well as a strong association with high-altitude regions. In this study, we use mitogenomic data to infer the phylogenetic relationships among diurnal, phytotelm-breeding Melanophryniscus and to determine the timing of their divergence. We obtained the mitochondrial genomes (not including the control region) for eight individuals of Melanophryniscus representing all three described species (M. alipioi, M. milanoi, and M. xanthostomus), as well as some recently-discovered and potentially new species. Gene order was conserved in all species and corresponded to the general order found in bufonids. Although the phylogenetic relationships among the studied species was poorly supported, dating confirmed that they diverged during the Pleistocene, suggesting that phytotelm breeding could have arisen during drier periods in the glacial/interglacial cycles due to a decrease in the availability of permanent streams or ephemeral/temporary streams or ponds in which Melanophryniscus species commonly breed. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Niche overlap and resource partitioning among five sympatric bufonids (Anura, Bufonidae from northeastern Argentina

    Directory of Open Access Journals (Sweden)

    Marta I. Duré

    2009-07-01

    Full Text Available The niche overlap and resource partitioning were analyzed for five sympatric bufonids from Northeastern Argentina: Rhinella schneideri, R. bergi, R. fernandezae, R. granulosa, and Melanophryniscus cupreuscapularis. The primary objectives were to analyze the diet and pattern of coexistence relative to the microhabitats among species. The bufonids, which are primarily terrestrial, exhibited a preference for small, hard prey such as formicids or coleopterans. The smallest species preferably consumed ants, while R. schneideri preferred beetles. Significant differences were detected for the diets of these five species. In addition, significant overlap in the trophic niche was noted for all species except between R. granulosa and R. schneideri. Studying the diet behaviors and trophic parameters of sympatric species provides important data for understandingthe community and for the development of conservation guidelines.

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

    Science.gov (United States)

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

    2013-12-01

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

  12. Further studies on pumiliotoxin 251D and hydroquinone content of the skin secretion of Melanophryniscus species (Anura, Bufonidae) from Uruguay.

    Science.gov (United States)

    Mebs, Dietrich; Maneyro, Raúl; Pogoda, Werner

    2007-07-01

    In whole animal ethanolic extracts from adult specimens of Melanophryniscus atroluteus (27 specimens) and M. devincenzii (16 specimens) as well as of two egg clutches and four tadpole samples from the latter species, the major alkaloid pumiliotoxin (PTX) 251D and hydroquinone were assayed quantitatively by gas chromatography/mass spectrometry. All toad extracts contained high concentrations of PTX 251D and hydroquinone and exhibited considerable variation in the content of these compounds among individual specimens. The extracts of the eggs and tadpoles were entirely free of alkaloids as well as hydroquinone, pointing to a dietary origin of these compounds.

  13. TOAD Gateway

    Science.gov (United States)

    Bingel, Bradford D.

    1994-01-01

    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.

  14. Phylogenetic relationships and call structure in four African bufonid ...

    African Journals Online (AJOL)

    Phylogenetic relationships and call structure in four African bufonid species. ... The evolution of advertisement call structure in these species is discussed in relation to this phylogeny. ... The phylogeny derived from allozyme data agrees with evidence on albumin immunological distance, karyotype and morphology.

  15. Aspects of the reproductive ecology and behavior of the tepui toads, genus Oreophrynella (Anura: Bufonidae)

    Science.gov (United States)

    McDiarmid, R.W.; Gorzula, S.

    1989-01-01

    We report direct development for toads of the bufonid genus Oreophrynella, endemic to the tepuis of the Guayanan Highlands. Tepui toads place few (9-13), large (-3 mm diameter) eggs in a single or communal terrestrial nest. One communal nest found on Kukenan-tepui contained 102 toads (70 males, 30 females, 2 hatchlings) and 321 eggs in clumps of 8-35. All viable clutches from Kukenan were attended by an adult. One clutch of 13 eggs from Ilu-tepui was without an attendant adult. Calls of Kukenan males consist of 9-16 partially pulsed notes given at a rate of 5-7 notes per second. Calls and notes were modulated and increased or decreased in frequency; dominant frequencies of the calls ranged between 2650-3650 Hz. Tepui toads are diurnal, rock dwellers with a slow, deliberate walking gait. An unusual balling and tumbling behavior and bright colored venter may be associated with predator avoidance in some populations. Remarkable parallels in reproductive ecology and behavior between Oreophynella and montane populations of the African bufonid Nectophrynoides are noted.

  16. Characterisation of Major Histocompatibility Complex Class I in the Australian Cane Toad, Rhinella marina

    Science.gov (United States)

    Lillie, Mette; Shine, Richard; Belov, Katherine

    2014-01-01

    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

  17. Alimentación en Melanophryniscus stelzneri (Anura: Bufonidae

    Directory of Open Access Journals (Sweden)

    Fillipelo, Ana María

    1994-01-01

    Full Text Available The alimentary categories of a population of Melanophryniscus stelzneri are studied cuantitatively and cualitatively utilizing a sample of 57 specimens obtained from "El Trapiche", province of San Luis, Argentine, in order to know the grade of trophic overlap and predation strategies. The main alimentary categories for males and females are: Formicidae, Collembola, Acari, Coleoptera, Isoptera and larvae. Although the diets of both sexes show a high grade of trophic overlap, males and females differ in the amount of each resource used. Adults and juveniles present a low grade of trophic overlap. The juveniles follow the "widely foraging" strategy and the adults follow an intermidiate one, between "sit and wait" and "widely foraging".

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

    Science.gov (United States)

    Shine, Richard

    2010-09-01

    aversion to toads as prey items, and physiological vulnerability to bufotoxins as a result of a lack of coevolutionary history of exposure to other bufonid taxa.

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

    Science.gov (United States)

    2009-01-01

    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. PMID:19968866

  20. The Sri Lankan torrent toads (Bufonidae: Adenominae: Adenomus): species boundaries assessed using multiple criteria.

    Science.gov (United States)

    Meegaskumbura, Madhava; Senevirathne, Gayani; Wijayathilaka, Nayana; Jayawardena, Beneeta; Bandara, Champika; Manamendra-Arachchi, Kelum; Pethiyagoda, Rohan

    2015-01-19

    The bufonid genus Adenomus, an endemic of the montane and lowland rainforests of central and south-western Sri Lanka, has been considered to comprise of three species, viz. A. kelaartii, A. dasi and A. kandianus, the last of which has been recently highlighted as "the world's rarest toad". We conducted a survey across the known range of Adenomus and used multiple criteria to delineate species boundaries within the genus. These include: a molecular phylogeny based on a 16S ribosomal RNA gene fragment; an examination of the external morphology of adults and larvae, and the skeletal morphology of adults; a bioacoustic analysis; and ecological niche modelling. We show that Adenomus is monophyletic and that it comprises only two species: A. kelaartii and A. kandianus, with A. dasi being a junior synonym of the latter. For the two valid species of Adenomus, we provide detailed osteological descriptions; clarify the distribution patterns; and provide genetic data to facilitate their scientific conservation management. 

  1. Three New Species of Phytotelm-Breeding Melanophryniscus from the Atlantic Rainforest of Southern Brazil (Anura: Bufonidae).

    Science.gov (United States)

    Bornschein, Marcos R; Firkowski, Carina R; Baldo, Diego; Ribeiro, Luiz F; Belmonte-Lopes, Ricardo; Corrêa, Leandro; Morato, Sérgio A A; Pie, Marcio R

    2015-01-01

    Three new species of Melanophryniscus are described from the Serra do Mar mountain range of the state of Santa Catarina, southern Brazil. All species are found at intermediate to high altitudes and share phytotelm-breeding as their reproductive strategy. The new species are distinguished from other phytotelm-breeding Melanophryniscus based on different combinations of the following traits: snout-vent length, presence of white and/or yellow spots on forearms, mouth, belly and cloaca, pattern and arrangement of warts, and presence and number of corneous spines. The discovery of these species in a rather restricted geographical area suggests that the diversity of phytotelm-breeding species of Melanophryniscus might be severely underestimated. The conservation status of these species is of particular concern, given that one of them is at risk of extinction not only due to its restricted habitat, but also because of anthropogenic disturbances.

  2. Three New Species of Phytotelm-Breeding Melanophryniscus from the Atlantic Rainforest of Southern Brazil (Anura: Bufonidae.

    Directory of Open Access Journals (Sweden)

    Marcos R Bornschein

    Full Text Available Three new species of Melanophryniscus are described from the Serra do Mar mountain range of the state of Santa Catarina, southern Brazil. All species are found at intermediate to high altitudes and share phytotelm-breeding as their reproductive strategy. The new species are distinguished from other phytotelm-breeding Melanophryniscus based on different combinations of the following traits: snout-vent length, presence of white and/or yellow spots on forearms, mouth, belly and cloaca, pattern and arrangement of warts, and presence and number of corneous spines. The discovery of these species in a rather restricted geographical area suggests that the diversity of phytotelm-breeding species of Melanophryniscus might be severely underestimated. The conservation status of these species is of particular concern, given that one of them is at risk of extinction not only due to its restricted habitat, but also because of anthropogenic disturbances.

  3. Three New Species of Phytotelm-Breeding Melanophryniscus from the Atlantic Rainforest of Southern Brazil (Anura: Bufonidae)

    Science.gov (United States)

    Bornschein, Marcos R.; Firkowski, Carina R.; Baldo, Diego; Ribeiro, Luiz F.; Belmonte-Lopes, Ricardo; Corrêa, Leandro; Morato, Sérgio A. A.; Pie, Marcio R.

    2015-01-01

    Three new species of Melanophryniscus are described from the Serra do Mar mountain range of the state of Santa Catarina, southern Brazil. All species are found at intermediate to high altitudes and share phytotelm-breeding as their reproductive strategy. The new species are distinguished from other phytotelm-breeding Melanophryniscus based on different combinations of the following traits: snout-vent length, presence of white and/or yellow spots on forearms, mouth, belly and cloaca, pattern and arrangement of warts, and presence and number of corneous spines. The discovery of these species in a rather restricted geographical area suggests that the diversity of phytotelm-breeding species of Melanophryniscus might be severely underestimated. The conservation status of these species is of particular concern, given that one of them is at risk of extinction not only due to its restricted habitat, but also because of anthropogenic disturbances. PMID:26630281

  4. The complex evolutionary history of the tympanic middle ear in frogs and toads (Anura)

    Science.gov (United States)

    Pereyra, Martín O.; Womack, Molly C.; Barrionuevo, J. Sebastián; Blotto, Boris L.; Baldo, Diego; Targino, Mariane; Ospina-Sarria, Jhon Jairo; Guayasamin, Juan M.; Coloma, Luis A.; Hoke, Kim L.; Grant, Taran; Faivovich, Julián

    2016-01-01

    Most anurans possess a tympanic middle ear (TME) that transmits sound waves to the inner ear; however, numerous species lack some or all TME components. To understand the evolution of these structures, we undertook a comprehensive assessment of their occurrence across anurans and performed ancestral character state reconstructions. Our analysis indicates that the TME was completely lost at least 38 independent times in Anura. The inferred evolutionary history of the TME is exceptionally complex in true toads (Bufonidae), where it was lost in the most recent common ancestor, preceding a radiation of >150 earless species. Following that initial loss, independent regains of some or all TME structures were inferred within two minor clades and in a radiation of >400 species. The reappearance of the TME in the latter clade was followed by at least 10 losses of the entire TME. The many losses and gains of the TME in anurans is unparalleled among tetrapods. Our results show that anurans, and especially bufonid toads, are an excellent model to study the behavioural correlates of earlessness, extratympanic sound pathways, and the genetic and developmental mechanisms that underlie the morphogenesis of TME structures. PMID:27677839

  5. Variación de la coloración en poblaciones argentinas de Melanophryniscus rubriventris (Vellard, 1947

    Directory of Open Access Journals (Sweden)

    Vaira, Marcos

    2002-12-01

    Full Text Available Tanto los patrones como el tono de la coloración dorsal y ventral han sido caracteres comúnmente utilizados para el reconocimiento y diferenciación de numerosas especies y subespecies del género de Bufonidae Melanophryniscus. Sin embargo, raramente se han presentado análisis detallados y sistematizados que indiquen la ausencia o la baja frecuencia de polimorfismos en estos caracteres para asegurar que son realmente diagnósticos. Mediante una metodología sistematizada se estableció la validez diagnóstica de estos caracteres para las poblaciones argentinas de Melanophryniscus rubriventris. La información obtenida en este trabajo, sugiere la existencia de poblaciones con variaciones morfológicas distintivas aunque no exclusivas y se propone que las actuales subespecies sean sinonimizadas. Dada la importante variabilidad registrada en los patrones de coloración de ejemplares conservados y de la intensidad de la coloración in vivo en todo el rango de distribución de Melanophryniscus rubriventris, así como la multiplicidad de fuentes de variabilidad que estos caracteres pueden expresar, se sugiere que el uso de la coloración como carácter diagnóstico único para la delimitación de especies sea utilizado con cierta precaución o empleando una metodología de muestreo rigurosa que contemple la edad, el sexo y la mayor cantidad posible de poblaciones en todo el rango de distribución del grupo a investigar. Both, patterns and hue of dorsal and ventral coloration were commonly utilized in species and subspecies recognition in the genus of Bufonidae Melanophryniscus. However, no detailed and systematized analysis were presented to determine if such characters are truly fixed. I determine the validity of these attributes as truly diagnostic characters in different populations of Melanophryniscus rubriventris of Argentina. The evidence obtained suggest the existence of sets of populations which differ only in trait frequencies and I

  6. A new species of Melanophryniscus (Anura, Bufonidae from the Campos Gerais region of Southern Brazil

    Directory of Open Access Journals (Sweden)

    Giovanna C. Steinbach-Padilha

    2008-12-01

    Full Text Available A new species of Melanophryniscus is described from the Parque Estadual de Vila Velha, municipality of Ponta Grossa, Paraná State,Southern Brazil. The Parque Estadual de Vila Velha is located in the Campos Gerais region, an environment dominated by natural grasslands with patches of Araucaria Forest. The new species is distinguished from all congeners by its small size (12.8-14.0 mm snout-vent length in adult males and unique color pattern of copper brown dorsum covered with small spinulose black warts; ventral surface black finely spotted with white, posterior abdomen and ventral surfaces of the forearm, hand and foot with red stains. The new species is nocturnal and breeds in the water accumulated in the leaf-axils of phytotelmata.

  7. Historical biogeography resolves the origins of endemic Arabian toad lineages (Anura: Bufonidae): Evidence for ancient vicariance and dispersal events with the Horn of Africa and South Asia.

    Science.gov (United States)

    Portik, Daniel M; Papenfuss, Theodore J

    2015-08-06

    The Arabian Peninsula is home to a unique fauna that has assembled and evolved throughout the course of major geophysical events, including the separation of the Arabian Plate from Africa and subsequent collision with Eurasia. Opportunities for faunal exchanges with particular continents occurred in temporally distinct periods, and the presence of African, Western Eurasian, and South Asian derived taxa on the Arabian Peninsula signifies the complexity of these historical biogeographic events. The six true toad species (family Bufonidae) endemic to Arabian Peninsula present a considerable taxonomic and biogeographic challenge because they are part of a global bufonid radiation, including several genera surrounding the Arabian Peninsula, and difficult to discriminate morphologically. As they could be derived from African, Western Eurasian, or South Asian toad groups, elucidating their evolutionary relationships has important implications for historical biogeography. Here, we analyze a global molecular data set of 243 bufonid lineages, with an emphasis on new sampling from the Horn of Africa, Western Eurasia, South Asia, and the Arabian Peninsula, to reconstruct the evolutionary relationships of the Arabian species. We produce a robust time-calibrated phylogeny to infer the biogeographic history of this group on and around the Arabian Peninsula. Our phylogenetic analyses indicate two of the endemic Arabian toad species, "Bufo" tihamicus and "Bufo" arabicus, evolved independently within the African genus Amietophrynus. We confirm the Arabian species Duttaphrynus dhufarensis is of South Asian origin, but do not find evidence for the Asian genus Duttaphrynus being present in the Horn of Africa, discrediting a previously proposed Asian bufonid dispersal event to Africa. We also do not find evidence of the African genus Amietophrynus occurring in South Asia, suggesting that unlike many other vertebrate taxa, toads have not used the Arabian Peninsula as a stepping-stone for

  8. Características histológicas de la tumefacción frontal de Melanophryniscus (Amphibia: Anura: Bufonidae Histological features of the frontal tumefaction in Melanophryniscus (Amphibia: Anura: Bufonidae

    Directory of Open Access Journals (Sweden)

    DANIEL E. NAYA

    2004-12-01

    Full Text Available Se analizó la histología tegumentaria de la región cefálica en seis especies del género Melanophryniscus, pertenecientes a los grupos stelzneri (4 y tumifrons (2, con el objetivo de esclarecer la estructura de la tumefacción frontal y su posible función. Las características generales de la histología del grupo stelzneri, coincidieron con las descripciones tegumentarias existentes para el género. Sin embargo, la región cefálica frontal en las dos especies del grupo tumifrons muestran cambios histológicos correlacionados a la tumefacción frontal. Esta estructura presenta una organización similar a otras macroglándulas presentes en la dermis de anuros (e.g., parotoides, paracnémicas, y por tanto se propone el nombre de macroglándula frontal para la misma. Los resultados obtenidos sugieren un rol defensivo para esta macroglándulaWe analyzed the histology of skin from the head region of six species of Melanophryniscus, belonging to the stelzneri (4 and tumifrons (2 groups, to understand the frontal tumefaction structure and function. The histological features of the skin in the stelzneri group are in agreement with the current description for the genus Melanophryniscus. However, the features of the skin on the anterior head region of M. tumifrons shows several changes associated with the frontal tumefaction. This structure consists of a macrogland of similar organization to that of other dermic glands (e.g., parotoid, paracnemid of amphibians. We propose the name frontal macrogland for this structure. Our results suggest a possible defense role for this macrogland

  9. Use of Reproductive Microhabitat by Melanophryniscus montevidensis (Anura: Bufonidae) from Uruguay.

    Science.gov (United States)

    Pereira, Gisela; Maneyro, Raúl

    2016-08-01

    This study describes the reproductive microhabitat of Melanophryniscus montevidensis and its use in two water bodies (WBs) in Barra de la Laguna de Rocha, Uruguay. Monthly field trips were performed between March 2012 and February 2013. Variables related to the WBs and vegetation, as well as parameters linked to the usage the amphibians make of the site (e.g: distance to the border of the pond, water depth and the vegetation use) were recorded. The behavior shown by the individuals during the breeding activity was recorded. This activity occurs in shallow temporary WBs with abundant hydrophilic vegetation. The individuals were found more frequently in areas near the edge of the pond, which has denser vegetation. The calling males were found closer to the border of the pond, and they showed better body condition than the non-calling males. In addition to calling activities, males used alternative tactics to find couples, such as active search of females, and aggressive behaviors, such as male displacing and physical combat. Such behaviors are common in anurans with explosive reproductive dynamics. The characterization of the reproductive microhabitats permits the proposal of strategies for the conservation of the species in Uruguay, given that the loss and fragmentation of habitats is one of the main causes considered for the decrease in their populations.

  10. Validity of photo-identification technique to analyze natural markings in Melanophryniscus montevidensis (Anura: Bufonidae

    Directory of Open Access Journals (Sweden)

    Ernesto Elgue

    2014-08-01

    Full Text Available Individual identification is useful for answering a variety of biological questions about animal life histories. Most of the techniques used to mark amphibians are invasive and can cause negative effects, compromising individual survivorship and biasing studies. Photo-identification consists in the identification of specimens based on photographic records of unique color-design patterns. This technique has been used with success in several amphibian species. Melanophryniscus montevidensis is an endangered anuran species inhabiting the Uruguayan Atlantic coast. The general pattern of coloration is black with red and yellow blotches on the belly. In this study, we validated the technique of photo-identification assisted by software for individual recognition in M. montevidensis using natural markings. Field trips were performed over 16 months during which, the ventral color pattern of specimens was photographed. The photos were edited and analyzed with the Wild-ID 1.0 software for photographic reconnaissance. An efficiency of 100% was obtained in the visual recognition and 90% in the detection of recaptures using the software. The use of photo-identification using natural marks is an effective technique in this species, because the color pattern of the belly was highly variable among individuals and remained unchanged in individuals over the 16 month period. In this evaluation the use of software for photo-identification was necessary for the treatment of large databases.

  11. Mechanical properties of the hindlimb bones of bullfrogs and cane toads in bending and torsion.

    Science.gov (United States)

    Wilson, Megan P; Espinoza, Nora R; Shah, Sagar R; Blob, Richard W

    2009-07-01

    When compared with most vertebrates, frogs use a novel style of jumping locomotion powered by the hindlimbs. Hindlimb bones of frogs must withstand the potentially erratic loads associated with such saltatory locomotion. To evaluate the load bearing capacity of anuran limb bones, we used three-point bending, torsion, and hardness tests to measure the mechanical properties of the femur and tibiofibula from adults of two species that use different jumping styles: explosively jumping bullfrogs (Rana (Lithobates) catesbeiana) and cyclically hopping cane toads (Bufo (Chaunus) marinus). Yield stress and strain values for R. catesbeiana and B. marinus hindlimb bones are within the range of values previously reported for other vertebrates. However, anuran hindlimb bones generally stand out as having higher yield stresses in bending than those of closely related, nonsaltatory salamanders, highlighting the importance of considering phylogenetic context in comparisons of bone functional capacity and adaptation. Stiffness values for both frog species tested were also high, which may facilitate efficient transmission of muscular forces while jumping. Elevated stiffness may also contribute to some discrepancies between determinations of bone properties via hardness versus bending tests. In comparisons between species, B. marinus bones showed significantly higher bending yield stresses than R. catesbeiana, whereas R. catesbeiana bones showed significantly higher torsional yield stresses than B. marinus. These differences may correlate with differences in jumping style and limb anatomy between ranid and bufonid frogs, suggesting that evolutionary changes in bone mechanical properties may help to accommodate new functional demands that emerge in lineages.

  12. Reproducción y desarrollo larval del sapo enano Melanophryniscus stelzneri stelzneri (Weyemberg, 1875 (Anura: Bufonidae

    Directory of Open Access Journals (Sweden)

    Bustos Singer, Rodrigo

    1997-01-01

    Full Text Available Se estudiaron varios aspectos de la reproducción y desarrollo larval de Melanophryniscus stelzneri stelzneri: condiciones ambientales en las que ocurre la reproducción, conductas pre y postreproductivas de los adultos, puesta, desarrollo embrionario, comportamiento larval, y metamorfosis. Se realizó también una descripción anatómica de la larva. La mayor parte de las conductas observadas son corrientes en anuros argentinos. La larva es típicamente pequeña y de tipo léntico-bentónica. Su fórmula dentaria mas común es 2 / 3. El tiempo de metamorfosis está afectada por la disponibilidad de agua, un paulatino descenso en el nivel de agua la acelera. Many aspects about the reproduction of Melanophryniscus stelzneri stelzneri were estudied: environmental conditions in which reproduction occurs, pre and postreproductive adult behaviour, oviposition, larval developement, tadpole habits and metamorphosis. An anatomic description of the larva was also realized. Most of the observed behaviours are usual in argentinian anurans. The tadpole is tiny and typically lentic- bentonic. The most conmon queratodontic formula is 2 / 3. The time of metamorphosis is affected by water availability. A decreasing level of water accelerates the development.

  13. Chloride channels in toad skin

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Rasmussen, B E

    1982-01-01

    A study of the voltage and time dependence of a transepithelial Cl- current in toad skin (Bufo bufo) by the voltage-clamp method leads to the conclusion that potential has a dual role for Cl- transport. One is to control the permeability of an apical membrane Cl-pathway, the other is to drive Cl-......- transport through open channels does not obey the constant-field equation....

  14. Diseases of frogs and toads

    Science.gov (United States)

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

    2005-01-01

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

  15. conservation efforts of kihansi spray toad nectophrynoides ...

    African Journals Online (AJOL)

    Mr and Mrs Goboro

    visual surveys according to Howell (2002) were used to survey the wetlands in which the toads have been reintroduced and systematic walks along transects were employed to count all the detected KSTs and other amphibians (Harper et al.

  16. Phylogeography of the African common toad, Amietophrynus ...

    African Journals Online (AJOL)

    Phylogeography of the African common toad, Amietophrynus regularis, based on mitochondrial DNA sequences: inferences regarding the Cape Verde population and biogeographical patterns. R Vasconcelos, E. Froufe, JC Brito, S Carranza, DJ Harris ...

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

    Science.gov (United States)

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

    2015-01-01

    There are currently 34 genera and 410 species of toads in the world. The medicinal parts of toads mainly include their venom, skin, and clothing. The toad's venom and skin possess the same chemical components, mainly the toad venom lactone class, and their pharmacological effects primarily include the maintenance of strong heart, antitumor, antivirus, anti-infection, and analgesic effects. So far, the produces from the medicinal raw materials of the toad are widely used clinically around the world, especially in China, Japan, and South Korea. About 50 varieties of medicines are used in the clinical treatment of various complicated diseases in China, such as "Liushen pills" which was popular in the whole world. Toads are mainly used in treating malignant tumors (e.g., liver cancer, gastric cancer, esophageal cancer, colon cancer, cervical cancer, among others), and some major diseases such as hepatitis B. Despite the therapeutic effects of toad-derived medicines on human health, there is insufficient research and development of toad-derived medicines by leading drug companies. In order to harness the beneficial effects of the resources of the toad species, it is the responsibility of global pharmaceutical researchers to develop and generate economically feasible toad-derived therapeutic products, while promoting maximum protection to the resources of the toad species.

  18. Sulfate transport in toad skin

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Simonsen, K

    1988-01-01

    1. In short-circuited toad skin preparations exposed bilaterally to NaCl-Ringer's containing 1 mM SO2(-4), influx of sulfate was larger than efflux showing that the skin is capable of transporting sulfate actively in an inward direction. 2. This active transport was not abolished by substituting...... apical Na+ for K+. 3. Following voltage activation of the passive Cl- permeability of the mitochondria-rich (m.r.) cells sulfate flux-ratio increased to a value predicted from the Ussing flux-ratio equation for a monovalent anion. 4. In such skins, which were shown to exhibit vanishingly small leakage...... conductances, the variation of the rate coefficient for sulfate influx (y) was positively correlated with the rate coefficient for Cl- influx (x), y = 0.035 x - 0.0077 cm/sec (r = 0.9935, n = 15). 5. Addition of the phosphodiesterase inhibitor, 3-isobutyl-1-methyl-xanthine to the serosal bath of short...

  19. Diet alters species recognition in juvenile toads.

    Science.gov (United States)

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

    2013-10-23

    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.

  20. Toxins and pharmacologically active compounds from species of the family Bufonidae (Amphibia, Anura).

    Science.gov (United States)

    Rodríguez, Candelario; Rollins-Smith, Louise; Ibáñez, Roberto; Durant-Archibold, Armando A; Gutiérrez, Marcelino

    2017-02-23

    Among amphibians, 15 of the 47 species reported to be used in traditional medicines belong to the family Bufonidae, which demonstrates their potential in pharmacological and natural products research. For example, Asian and American tribes use the skin and the parotoid gland secretions of some common toads in the treatment of hemorrhages, bites and stings from venomous animals, skin and stomach disorders, as well as several types of cancers. In addition to reviewing the occurrence of chemical constituents present in the family Bufonidae, the cytotoxic and biomedical potential of the active compounds produced by different taxa are presented. Available information on bioactive compounds isolated from species of the family Bufonidae was obtained from ACS Publications, Google, Google Scholar, Pubmed, Sciendirect and Springer. Papers written in Chinese, English, German and Spanish were considered. Recent reports show more than 30% of amphibians are in decline and some of bufonid species are considered to be extinct. For centuries, bufonids have been used as traditional folk remedies to treat allergies, inflammation, cancer, infections and other ailments, highlighting their importance as a prolific source for novel drugs and therapies. Toxins and bioactive chemical constituents from skin and parotid gland secretions of bufonid species can be grouped in five families, the guanidine alkaloids isolated and characterized from Atelopus, the lipophilic alkaloids isolated from Melanophryniscus, the indole alkaloids and bufadienolides known to be synthesized by species of bufonids, and peptides and proteins isolated from the skin and gastrointestinal extracts of some common toads. Overall, the bioactive secretions of this family of anurans may have antimicrobial, protease inhibitor and anticancer properties, as well as being active at the neuromuscular level. In this article, the traditional uses, toxicity and pharmacological potential of chemical compounds from bufonids have

  1. Reported Experiences Enhance Favourable Attitudes toward Toads

    Science.gov (United States)

    Tomazic, Iztok

    2011-01-01

    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…

  2. Toad poisoning in three dogs: case reports

    Directory of Open Access Journals (Sweden)

    CM Barbosa

    2009-01-01

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

  3. Factors Affecting Students' Attitudes toward Toads

    Science.gov (United States)

    Tomažic, Iztok; Šorgo, Andrej

    2017-01-01

    Amphibians are one of the most threatened animal groups; however, attitudes and emotions toward them are mostly negative. One of the efforts, as a part of the cognitive dimension of nature protection, should be in the shifting of negative attitudes toward amphibians to positive ones. The purpose of this study was reevaluation of the Toad Attitude…

  4. Climate and land-use changes effects on the distribution of a regional endemism: Melanophryniscus sanmartini (Amphibia, Bufonidae

    Directory of Open Access Journals (Sweden)

    Nicole Rosenstock

    2015-06-01

    Full Text Available ABSTRACT Amphibians are the most threatened vertebrate group according to the IUCN. Land-use and land cover change (LULCC and climate change (CC are two of the main factors related to declining amphibian populations. Given the vulnerability of threatened and rare species, the study of their response to these impacts is a conservation priority. The aim of this work was to analyze the combined impact of LULCC and CC on the regionally endemic species Melanophryniscus sanmartini Klappenbach, 1968. This species is currently categorized as near threatened by the IUCN, and previous studies suggest negative effects of projected changes in climate. Using maximum entropy methods we modeled the effects of CC on the current and mid-century distribution of M. sanmartini under two IPCC scenarios - A2 (severe and B2 (moderate. The effects of LULCC were studied by superimposing the potential distribution with current land use, while future distribution models were evaluated under the scenario of maximum expansion of soybean and afforestation in Uruguay. The results suggest that M. sanmartini is distributed in eastern Uruguay and the south of Brazil, mainly related to hilly and grasslands systems. Currently more than 10% of this species' distribution is superimposed by agricultural crops and exotic forest plantations. Contrasting with a recent modelling study our models suggest an expansion of the distribution of M. sanmartini by mid-century under both climate scenarios. However, despite the rise in climatically suitable areas for the species in the future, LULCC projections indicate that the proportion of modified habitats will occupy up to 25% of the distribution of M. sanmartini. Future change in climate conditions could represent an opportunity for M. sanmartini, but management measures are needed to mitigate the effects of habitat modification in order to ensure its survival and allow the eventual expansion of its distribution.

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

    DEFF Research Database (Denmark)

    Spies, Ingrid B.M.

    1997-01-01

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

  6. Invasive cane toads: social facilitation depends upon an individual's personality.

    Directory of Open Access Journals (Sweden)

    Edna González-Bernal

    Full Text Available 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.

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

    Science.gov (United States)

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

    2014-01-01

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

  8. Estimation of temporary emigration in male toads.

    Science.gov (United States)

    Muths, Erin; Scherer, Rick D; Corn, Paul Stephen; Lambert, Brad A

    2006-04-01

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

  9. Hepatozoon species (Adeleorina: Hepatozoidae) of African bufonids, with morphological description and molecular diagnosis of Hepatozoon ixoxo sp. nov. parasitising three Amietophrynus species (Anura: Bufonidae).

    Science.gov (United States)

    Netherlands, Edward C; Cook, Courtney A; Smit, Nico J

    2014-12-20

    Haemogregarines comprise a large group of apicomplexan blood parasites. In 1996 all anuran haemogregarines still in the genus Haemogregarina Danilewsky, 1885 were reassigned to the genus Hepatozoon Miller, 1908. Most (11/15, 73%) African anuran Hepatozoon species have been recorded from the family Bufonidae, however, all these are recorded from only two host species, Amietophrynus mauritanicus (Schlegel, 1841) and Amietophrynus regularis (Reuss, 1833) from Northern and central Africa. To the authors' knowledge the only description of an anuran haemogregarine from South Africa is Hepatozoon theileri (Laveran, 1905), parasitising Amietia quecketti (Boulenger, 1895). Thin blood smears for morphometrics and whole blood for molecular work, were collected from 32 Amietophrynus garmani (Meek, 1897), 12 Amietophrynus gutturalis (Power, 1927), and nine Amietophrynus maculatus (Hallowell, 1854), in Ndumo Game Reserve and Kwa Nyamazane Conservancy, KwaZulu-Natal, South Africa. Smears were Giemsa-stained, screened for haemogregarines, parasite stages measured, compared to each other and to other described African bufonid haemogregarines. Parasite 18S rDNA was amplified using two apicomplexan-specific primer sets, HepF300/HepR900 and 4558/2733. Resulting sequences of the haemogregarine isolates from the three Amietophrynus species were compared with each other and to comparative haemogregarine sequences selected from GenBank. Morphological characteristics of parasite stages, in particular characteristically capped mature gamont stages, and molecular findings, supported all three haemogregarine isolates from all three Amietophrynus species to be the same, a species of Hepatozoon, and furthermore different morphologically from other previously recorded bufonid Hepatozoon species. The haemogregarine fell within a clade comprising other anuran Hepatozoon species and furthermore, within a monophyletic sub-clade along with H. theileri and are described as Hepatozoon ixoxo sp. nov

  10. Sexual differences in the ecology and habitat selection of western toads (Bufo boreas) in northeastern Oregon.

    Science.gov (United States)

    Evelyn L. Bull

    2006-01-01

    Several species of toads (family Bufonidae), including the Western Toad (bufo boreas) have declined in the Western United States. Information on toad ecology and habitat use is essential to determine potential causes for population declines, as is the potential relationship between this information and disturbance events. Aspects of western toad...

  11. Breeding frequency of western toads (Bufo boreas) in northeastern Oregeon

    Science.gov (United States)

    Evelyn L. Bull; Cynthia Carey

    2008-01-01

    Many species of toads (family Bufonidae), including the western toad (Bufo boreas), are declining in-the western United States. The ability of this species to recover from declines depends, in part, on its reproductive success. This study examined the breeding frequency in both sexes of B. borelis in northeastern Oregon compared to...

  12. Further Hopping with Toads and Frogs

    OpenAIRE

    Thanatipanonda, Thotsaporn "Aek"

    2008-01-01

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

  13. Microbiome-Mediated Biotransformation of Cane Toad Bufagenins.

    Science.gov (United States)

    Kamalakkannan, Venkatanambi; Salim, Angela A; Capon, Robert J

    2017-07-28

    Cane toads are an invasive pest species in which all life stages employ cardiotoxic bufagenins as a chemical defense against predators. Curiously, the bufagenin profiles of eggs and tadpoles are more complex than those of parotoid secretion, the principle mechanism of toxin delivery in adult toads. In an effort to understand this complexity, we determined that selected strains of adult toad parotoid-gland-associated Gram-positive bacteria, Bacillus spp., were capable of biotransforming secreted bufagenins, marinobufagenin (1), telocinobufagenin (2), bufalin (3), and resibufagenin (4), to hydroxylated scaffolds commonly encountered in cane toad eggs and tadpoles. Scaled-up cultivation, preparative chromatography, and detailed spectroscopic analysis identified Bacillus sp. CMB-TD29 biotransformation products of 1, as 11α-hydroxymarinobufagenin (6), 12β-hydroxymarinobufagenin (7), and 17α-hydroxymarinobufagenin (8). Comparative bufagenin profiles across the cane toad life cycle suggest that bacterial biotransformation mediates the oxidative adaptation of adult toad bufagenins to hydroxylated bufagenins encountered in eggs and tadpoles. We speculate that knowledge of a relationship between the cane toad microbiome and bufagenin chemical defenses could inspire the development of a natural, nontoxic, environmentally sustainable bacterial biocontrol for this toxic invasive species.

  14. A new genus and species of arboreal toad with phytotelmonous larvae, from the Andaman Islands, India (Lissamphibia, Anura, Bufonidae)

    Science.gov (United States)

    Chandramouli, S. R.; Vasudevan, Karthikeyan; Harikrishnan, S.; Dutta, Sushil Kumar; Janani, S. Jegath; Sharma, Richa; Das, Indraneil; Aggarwal, Ramesh K.

    2016-01-01

    Abstract A new bufonid amphibian, belonging to a new monotypic genus, is described from the Andaman Islands, in the Bay of Bengal, Republic of India, based on unique external morphological and skeletal characters which are compared with those of known Oriental and other relevant bufonid genera. Blythophryne gen. n. is distinguished from other bufonid genera by its small adult size (mean SVL 24.02 mm), the presence of six presacral vertebrae, an absence of coccygeal expansions, presence of an elongated pair of parotoid glands, expanded discs at digit tips and phytotelmonous tadpoles that lack oral denticles. The taxonomic and phylogenetic position of the new taxon (that we named as Blythophryne beryet gen. et sp. n.) was ascertained by comparing its 12S and 16S partial genes with those of Oriental and other relevant bufonid lineages. Resulting molecular phylogeny supports the erection of a novel monotypic genus for this lineage from the Andaman Islands of India. PMID:26877687

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

    Science.gov (United States)

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

    2009-07-01

    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.

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

    Data.gov (United States)

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

  17. Effects of an invasive plant on population dynamics in toads.

    Science.gov (United States)

    Greenberg, Daniel A; Green, David M

    2013-10-01

    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. © 2013 Society for Conservation Biology.

  18. Bufo canorus Camp 1916, Yosemite Toad.

    Science.gov (United States)

    Davidson, Carlos; Fellers, Gary M.; Lannoo, Michael

    2005-01-01

    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).

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-02-15

    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.

  20. Factors limiting the recovery of boreal toads (Bufo b. boreas)

    Science.gov (United States)

    Carey, C.; Corn, P.S.; Jones, M.S.; Livo, L.J.; Muths, E.; Loeffler, C.W.; Lannoo, M.

    2005-01-01

    Boreal toads (Bufo b. boreas) are widely distributed over much of the mountainous western United States. Populations in the Southern Rocky Mountains suffered extensive declines in the late 1970s through early 1980s (Carey, 1993). At the time, these mass mortalities were thought to be associated with a bacterial infection (Carey, 1993). Although the few populations that survived the mass die-offs were not systematically monitored until at least 1993, no mass mortalities had been observed until 1996 when die-offs were observed. A mycotic skin infection associated with a chytrid fungus is now causing mortality of toads in at least two of the populations (M.S. Jones and D.E. Green, unpublished data; Muths et al., 2003). Boreal toads are now absent throughout large areas of their former distribution in Colorado and southern Wyoming and may be extinct in New Mexico (Corn et al., 1989; Carey, 1993; Stuart and Painter, 1994). These toads are classified as “endangered” by Colorado and New Mexico and are designated as a protected non-game species in Wyoming. The U.S. Fish and Wildlife Service has categorized the Southern Rocky Mountain populations for federal listing and is currently reviewing their designation as a “warranted but precluded” species for possible listing in the next few years. For the management of boreal toads and their habitats, a Boreal Toad Recovery Team was formed by the Colorado Division of Wildlife in 1995 as part of a collaborative effort with federal agencies within the United States’ departments of the Interior and Agriculture and with agencies in two adjoining states. To date, conservation agreements have been signed by eight state and federal agencies and by the Colorado Natural Heritage Program. Although boreal toads were considered common throughout their range in Colorado, no comprehensive surveys of the numbers and sizes of their populations were conducted prior to mass die-offs in the 1970s. Surveys completed in the late 1980s to

  1. Control of spatial orientation in terrestrial toads (Rhinella arenarum).

    Science.gov (United States)

    Daneri, M Florencia; Casanave, Emma; Muzio, Rubén N

    2011-08-01

    Three experiments were conducted to determine problem-solving strategies used by toads, Rhinella arenarum (= Bufo arenarum), in spatial learning situations, using water as reward. Experiment 1 showed that toads can acquire a spatial orientation based on a body-centered turn -an internal self-reference cue. Experiment 2 showed that toads can use a fixed landmark (visual cue) as guidance to solve a spatial problem. Experiment 3 determined whether maze learning was based on "body-centered turn" or "guidance". In this case, animals were trained with a fixed visual cue in relation to a body-centered turn (i.e., simultaneously with the internal self-reference cue) and then tested with the visual cue dissociated from positional cues. Toads trained with the combination of a visual cue and a body-centered turn preferred the latter (turn response) when the two sources of information were set in conflict on probe trials. Toads showed behavioral patterns similar to those described in rodents trained under similar condition, thus, suggesting an early evolutionary origin for these problem-solving strategies. PsycINFO Database Record (c) 2011 APA, all rights reserved.

  2. Observations on the breeding of toads in a restricted habitat

    African Journals Online (AJOL)

    prevent the overpopulation of the pond by tadpoles. Never- theless fairly large quantities of tadpoles did develop, and metamorphosis of some of them into toadlets was observed every year. The garden seems to have been an unfavourable biotope for the futher development of the toadlets, however, as juvenile toads were ...

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

    Science.gov (United States)

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

    2006-01-01

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

  4. Earless toads sense low frequencies but miss the high notes

    DEFF Research Database (Denmark)

    Womack, Molly C; Christensen-Dalsgaard, Jakob; Coloma, Luis A

    2017-01-01

    , four earless) within the Neotropical true toad family (Bufonidae). We found that species lacking middle ears are less sensitive to high-frequency sounds, however, low-frequency hearing and vibrational sensitivity are equivalent between eared and earless species. Furthermore, extratympanic hearing...

  5. DIET OF THE SOUTHERN TOAD 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 s...

  6. Conservation efforts of Kihansi spray toad Nectophrynoides asperginis

    African Journals Online (AJOL)

    Conservation efforts of Kihansi spray toad Nectophrynoides asperginis: its discovery, captive breeding, extinction in the wild and re-introduction. ... hydropower plant and the catchment ecosystem services have continued to provide electricity for domestic & industrial development and support human livelihoods respectively.

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

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Ussing, H H; Spring, K R

    1987-01-01

    The optical sectioning video imaging technique was used for measurements of the volume of mitochondria-rich (m.r.) cells of the isolated epithelium of toad skin. Under short-circuit conditions, cell volume decreased by about 14% in response to bilateral exposure to Cl-free (gluconate substitution...

  8. Phylogeny and biogeography of midwife toads (Alytes, Discoglossidae): a reappraisal

    NARCIS (Netherlands)

    Altaba, Cristian R.

    1997-01-01

    The allozyme data base of Arntzen & García-París (1995) on midwife toads (Alytes, Discoglossidae) is reanalysed considering each locus as a discrete character. The phylogeny thus inferred differs from the one obtained with genetic distances in the position of A. dickhilleni from the Betic region –

  9. On a new species of toad from southern Morocco

    NARCIS (Netherlands)

    Hoogmoed, M.S.

    1972-01-01

    A new species of toad, related with Bufo calamita Laurenti and B. viridis Laurenti, is described from the southern part of Morocco. Combining the data of the available specimens with literature records it was established that the new species probably ranges from the Sous valley southwards to Cape

  10. Biotic Resistance to an Alien Amphibian: Larval Competition between Japanese Frogs and Invasive Cane Toads.

    Science.gov (United States)

    Haramura, Takashi; Takeuchi, Hirohiko; Crossland, Michael R; Shine, Richard

    2016-01-01

    Understanding negative effects of native species on introduced taxa may suggest novel ways to control the invasive species by enhancing such effects. Previous studies have reported that the larvae of invasive cane toads (Rhinella marina) are suppressed by competition with the larvae of native anurans in Australia, but not in North America. We conducted laboratory trials to measure the effect of exposure to the larvae of Japanese frogs (Microhyla ornata, Fejervarya sakishimensis, Rhacophorus owstoni) on rates of survival, growth and development of cane toad tadpoles in Ishigaki Island, in southern Japan. Survival rates were not affected by native species, but competition with Dicroglossids and Rhacophorids (but not Microhylids) strongly reduced rates of growth and development in the tadpoles of cane toads. Dicroglossid tadpoles also reduced the body condition to toad tadpoles in addition to effects on SVL and mass. Encouraging populations of native frogs in toad-invaded areas of Japan thus may help to reduce the numbers of invasive cane toads.

  11. The impact of invasive cane toads on native wildlife in southern Australia.

    Science.gov (United States)

    Jolly, Christopher J; Shine, Richard; Greenlees, Matthew J

    2015-09-01

    Commonly, invaders have different impacts in different places. The spread of cane toads (Rhinella marina: Bufonidae) has been devastating for native fauna in tropical Australia, but the toads' impact remains unstudied in temperate-zone Australia. We surveyed habitat characteristics and fauna in campgrounds along the central eastern coast of Australia, in eight sites that have been colonized by cane toads and another eight that have not. The presence of cane toads was associated with lower faunal abundance and species richness, and a difference in species composition. Populations of three species of large lizards (land mullets Bellatorias major, eastern water dragons Intellagama lesueurii, and lace monitors Varanus varius) and a snake (red-bellied blacksnake Pseudechis porphyriacus) were lower (by 84 to 100%) in areas with toads. The scarcity of scavenging lace monitors in toad-invaded areas translated into a 52% decrease in rates of carrion removal (based on camera traps at bait stations) and an increase (by 61%) in numbers of brush turkeys (Alectura lathami). The invasion of cane toads through temperate-zone Australia appears to have reduced populations of at least four anurophagous predators, facilitated other taxa, and decreased rates of scavenging. Our data identify a paradox: The impacts of cane toads are at least as devastating in southern Australia as in the tropics, yet we know far more about toad invasion in the sparsely populated wilderness areas of tropical Australia than in the densely populated southeastern seaboard.

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

    Science.gov (United States)

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

    2011-01-01

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

  13. Age-related seasonal variation in captures of stream-borne Boreal Toads (Bufo boreas boreas, Bufonidae) in western Montana

    Science.gov (United States)

    Michael K. Young; David A. Schmetterling

    2009-01-01

    Like many species of amphibians, Boreal Toads (Bufo boreas boreas, Bufonidae) are declining throughout portions of their range. Recent efforts have focused on describing the ecology of this species, yet few studies have evaluated demographic characteristics that may influence the persistence of Boreal Toad populations. Because Boreal Toads often...

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

    Directory of Open Access Journals (Sweden)

    Isioma Tongo

    2012-07-01

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

  15. Habitat modeling and movements of the Yosemite toad (Anaxyrus (=Bufo) canorus) in the Sierra Nevada, California

    Science.gov (United States)

    C.T. Liang

    2010-01-01

    The Yosemite toad (Anaxyrus (=Bufo) canorus) is a high-elevation species endemic to the Sierra Nevada mountain range in California and is part of the world-wide amphibian declines phenomenon. The toad is thought to have disappeared from over 50% of its historic range even in seemingly undisturbed areas, and...

  16. Summer movements of boreal toads (Bufo boreas boreas) in two western Montana basins

    Science.gov (United States)

    David A. Schmetterling; Michael K. Young

    2008-01-01

    The Boreal Toad (Bufo boreas boreas) is widely distributed in the western United States but has declined in portions of its range. Research directed at conserving Boreal Toads has indicated that their movements are largely terrestrial and often limited after the breeding season. We used a combination of stream-based netting, PIT tagging, and radio...

  17. Determining the effects of cattle grazing treatments on Yosemite toads (Anaxyrus [=Bufo] canorus in montane meadows.

    Directory of Open Access Journals (Sweden)

    Susan K McIlroy

    Full Text Available Amphibians are experiencing a precipitous global decline, and population stability on public lands with multiple uses is a key concern for managers. In the Sierra Nevada Mountains (California, USA, managers have specifically identified livestock grazing as an activity that may negatively affect Yosemite toads due to the potential overlap of grazing with toad habitat. Grazing exclusion from Yosemite toad breeding and rearing areas and/or entire meadows have been proposed as possible management actions to alleviate the possible impact of cattle on this species. The primary objective of this study was to determine if different fencing treatments affect Yosemite toad populations. We specifically examined the effect of three fencing treatments on Yosemite toad breeding pool occupancy, tadpoles, and young of the year (YOY. Our hypothesis was that over the course of treatment implementation (2006 through 2010, Yosemite toad breeding pool occupancy and early life stage densities would increase within two fencing treatments relative to actively grazed meadows due to beneficial changes to habitat quality in the absence of grazing. Our results did not support our hypothesis, and showed no benefit to Yosemite toad presence or early life stages in fenced or partially fenced meadows compared to standard USDA Forest Service grazing levels. We found substantial Yosemite toad variation by both meadow and year. This variation was influenced by meadow wetness, with water table depth significant in both the tadpole and YOY models.

  18. Physiological and molecular mechanisms of inorganic phosphate handling in the toad Bufo bufo

    DEFF Research Database (Denmark)

    Møbjerg, Nadja; Werner, Andreas; Hansen, Sofie M

    2006-01-01

    The aim of this study was to elucidate mechanisms of P(i) handling in toads (Bufo bufo). We introduced toads to experimental solutions of various [P(i)] and high P(i) diets and measured urine and lymph [P(i)]. Both lymph and urine [P(i)] increased with increasing P(i) loads, indicating P...

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

    DEFF Research Database (Denmark)

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

    2007-01-01

    Blood cell flow (BCF) in the water absorbing "seat patch" region of toad skin was measured with laser Doppler flow cytometry. BCF of dehydrated toads increased by a factor of 6-8 when water contact was made and declined gradually as toads rehydrated. Water absorption was initially stimulated....... Aquaporins 1-3 were characterized by RT-PCR analysis of seat patch skin. AQP 1 was localized in the endothelium of subepidermal capillaries and serves as a pathway for water absorption in series with the apical and basolateral membranes of the epithelium. Dehydrated toads rehydrated more rapidly from dilute...... NaCl solutions than from deionized water despite the reduced osmotic gradient. BCF of toads rehydrating on 50 mM NaCl was not different than on deionized water and blocking Na+ transport with 100 microM amiloride did not reduce water absorption from 50 mM NaCl. Thus, neither circulation nor solute...

  20. Metabolic measures of male southern toads (Bufo terrestris) exposed to coal combustion waste

    Energy Technology Data Exchange (ETDEWEB)

    Ward, C.K.; Appel, A.G.; Mendonca, M.T. [Auburn University, Montgomery, AL (United States). Dept. of Biology

    2006-03-15

    Southern toads (Bufo terrestris) are found in coal fly ash collection basins associated with coal-burning electrical power plants. These basins contain large amounts of trace metals and organisms found in these basins are known to accumulate large quantities of metals. Studies on a variety of organisms exposed to trace metals found that they experience a significant increase in standard metabolic rate. We experimentally exposed southern toads to metal-contaminated sediment and food and measured changes in standard and exercise metabolic rates as well as changes in body, liver and muscle mass, blood glucose, and corticosterone. We found that toads exposed to trace metal contamination gained significantly less mass (18.3%) than control toads (31.3%) when food was limited and experienced significantly decreased RQ after exercise. However, contaminated toads did not experience changes in standard or exercise metabolic rates, plasma glucose levels, and hepatic or muscle percentage indices whether food was limited or not.

  1. Slope-Based and Geometric Encoding of a Goal Location by the Terrestrial Toad (Rhinella arenarum).

    Science.gov (United States)

    Sotelo, María Inés; Bingman, Verner P; Muzio, Rubén N

    2017-08-28

    The current study was designed to test for the ability of terrestrial toads, Rhinella arenarum, to use slope as source of spatial information to locate a goal, and investigate the relative importance of slope and geometric information for goal localization. Toads were trained to locate a single, water-reward goal location in a corner of a rectangular arena placed on an incline. Once the toads learned the task, 3 types of probe trials were carried out to determine the relative use of slope and geometric information for goal localization. The probe trials revealed that the toads were able to independently use slope, and as previously reported, geometry to locate the goal. However, the boundary geometry of the experimental arena was found to be preferentially used by the toads when geometric and slope information were set in conflict. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

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

    Science.gov (United States)

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

    2014-01-01

    The captive breeding program for the endangered Puerto Rican crested toad (Peltophryne [Bufo] lemur) has been hampered by an undiagnosed condition called "Brown Skin Disease" (BSD). Toads develop widespread skin darkening, skin thickening and abnormal shedding and eventually succumb to a chronic loss of viability. This project evaluated the marine toad (Bufo marinus) as a model for the PRCT, examining vitamin A deficiency as a potential cause of BSD. Wild caught marine toads had significantly higher liver vitamin A concentrations (61.89 ± 63.49 µg/g) than captive born marine toads (0.58 ± 0.59 µg/g); P<0.001). A significant difference in serum vitamin A concentration was found between the captive and wild caught toads (P=0.013) and between the low vitamin A-fed and wild caught toads (P=0.004), when controlling for liver vitamin A concentrations. After captive toads were treated with topical and/or oral vitamin A, their hepatic vitamin A concentrations were similar to those of the wild toads, averaging 48.41 ± 37.03 µg/g. However, plasma vitamin A concentrations pre- and post-vitamin A supplementation did not differ statistically. We concluded that plasma vitamin A concentrations do not provide a linear indication of liver/body vitamin A status, and that both topical and oral supplementation with an oil-based vitamin A formulation can increase liver stores in amphibians. No evidence of BSD or other signs of deficiency were noted in the marine toads, although this feeding trial was relatively short (127 days). To date, clinical, pathological and research findings do not support vitamin A deficiency as a primary factor underlying BSD. © 2014 Wiley Periodicals, Inc.

  3. Fatal chytridiomycosis and infection loss observed in captive toads infected in the wild

    Directory of Open Access Journals (Sweden)

    Vojtech Baláž

    2013-01-01

    Full Text Available A parasitic fungus, Batrachochytrium dendrobatidis is now recognised as an important factor in the amphibian biodiversity crisis. Toad species of the genus Bufo are among those susceptible to infection by the pathogen in Europe. The aim of this study was to observe the presence and impact of infection in adults of two toad species collected for captive breeding. The total number of animals included in the study was 162, but only subsets were used for sampling at different occasions (35 specimens in the initial sampling in summer 2011, 48 post hibernation during winter 2011, and 31 in summer 2012, after all toads in captivity were treated with itraconazole. We performed TaqMan real-time quantification PCR to detect and quantify the pathogen. We found that a large infection load was linked to mortality in a single adult green toad (Bufo viridis. However, low infection loads observed in five B. viridis and five natterjack toads (B. calamita were lost over time, with no apparent adverse effect. Intraconazole treated animals were all clear of infection. As infection in these two toad species either led to mortality or recovery, it seems unlikely they could act as permanent carriers of B. dendrobatidis and therefore persistence of the pathogen is likely maintained by different host species. This is the first study to date that has detected infection and observed its impact and persistence in wild-infected toads in Europe.

  4. Host-pathogen metapopulation dynamics suggest high elevation refugia for boreal toads

    Science.gov (United States)

    Mosher, Brittany A.; Bailey, Larissa L.; Muths, Erin L.; Huyvaert, Kathryn P

    2018-01-01

    Emerging infectious diseases are an increasingly common threat to wildlife. Chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), is an emerging infectious disease that has been linked to amphibian declines around the world. Few studies exist that explore amphibian-Bd dynamics at the landscape scale, limiting our ability to identify which factors are associated with variation in population susceptibility and to develop effective in situdisease management. Declines of boreal toads (Anaxyrus boreas boreas) in the Southern Rocky Mountains are largely attributed to chytridiomycosis but variation exists in local extinction of boreal toads across this metapopulation. Using a large-scale historic dataset, we explored several potential factors influencing disease dynamics in the boreal toad-Bd system: geographic isolation of populations, amphibian community richness, elevational differences, and habitat permanence. We found evidence that boreal toad extinction risk was lowest at high elevations where temperatures may be sub-optimal for Bd growth and where small boreal toad populations may be below the threshold needed for efficient pathogen transmission. In addition, boreal toads were more likely to recolonize high elevation sites after local extinction, again suggesting that high elevations may provide refuge from disease for boreal toads. We illustrate a modeling framework that will be useful to natural resource managers striving to make decisions in amphibian-Bdsystems. Our data suggest that in the southern Rocky Mountains high elevation sites should be prioritized for conservation initiatives like reintroductions.

  5. The impact of transportation and translocation on dispersal behaviour in the invasive cane toad.

    Science.gov (United States)

    Pettit, Lachlan; Greenlees, Matthew; Shine, Richard

    2017-06-01

    Biological invasions transport organisms to novel environments; but how does the translocation process influence movement patterns of the invader? Plausibly, the stress of encountering a novel environment, or of the transport process, might induce rapid dispersal from the release site-potentially enhancing (or reducing) invader success and spread. We investigated the effect of transportation and release to novel environments on dispersal-relevant traits of one of the world's most notorious invaders, the cane toad (Rhinella marina). We collected toads in northern New South Wales from heath and woodland habitats, manipulated the level of transport stress and either returned toads to their exact collection point (residents) or reciprocally translocated them to a novel site. Both translocation and the level of transport stress drastically altered toad dispersal rates for at least 5 days post-release. Translocated toads (depending on their level of transport stress and release habitat) moved on average two to five times further per day (mean range 67-148 m) than did residents (mean range 22-34 m). Translocated toads also moved on more days, and moved further from their release point than did resident toads, but did not move in straighter lines. A higher level of transport stress (simulating long-distance translocation) had no significant effect on movements of resident toads but amplified the dispersal of translocated toads only when released into woodland habitat. These behavioural shifts induced by translocation and transportation may affect an invader's ability to colonise novel sites, and need to be incorporated into plans for invader control.

  6. Winter hibernation and UCHL1-p34cdc2 association in toad oocyte maturation competence.

    Directory of Open Access Journals (Sweden)

    Zhichao Kuang

    Full Text Available Currently, it is believed that toad oocyte maturation is dependent on the physiological conditions of winter hibernation. Previous antibody-blocking experiments have demonstrated that toad ubiquitin carboxyl-terminal hydrolase L1 (tUCHL1 is necessary for germinal vesicle breakdown during toad oocyte maturation. In this paper, we first supply evidence that tUCHL1 is highly evolutionarily conserved. Then, we exclude protein availability and ubiquitin carboxyl-terminal hydrolase enzyme activity as factors in the response of oocytes to winter hibernation. In the context of MPF (maturation promoting factor controlling oocyte maturation and to further understand the role of UCHL1 in oocyte maturation, we performed adsorption and co-immunoprecipitation experiments using toad oocyte protein extracts and determined that tUCHL1 is associated with MPF in toad oocytes. Recombinant tUCHL1 absorbed p34(cdc2, a component of MPF, in obviously larger quantities from mature oocytes than from immature oocytes, and p13(suc1 was isolated from tUCHL1 with a dependence on the ATP regeneration system, suggesting that still other functions may be involved in their association that require phosphorylation. In oocytes from hibernation-interrupted toads, the p34(cdc2 protein level was significantly lower than in oocytes from toads in artificial hibernation, providing an explanation for the different quantities isolated by recombinant tUCHL1 pull-down and, more importantly, identifying a mechanism involved in the toad oocyte's dependence on a low environmental temperature during winter hibernation. Therefore, in toads, tUCHL1 binds p34(cdc2 and plays a role in oocyte maturation. However, neither tUCHL1 nor cyclin B1 respond to low temperatures to facilitate oocyte maturation competence during winter hibernation.

  7. Cane toads lack physiological enhancements for dispersal at the invasive front in Northern Australia

    Directory of Open Access Journals (Sweden)

    Christopher R. Tracy

    2011-11-01

    Many invasive species have evolved behavioural and morphological characteristics that facilitate their dispersal into new areas, but it is unclear how selection on this level of the phenotype filters through to the underlying physiology. Cane toads have been dispersing westward across northern tropical Australia for more than 70 years. Previous studies of cane toads at the invasive front have identified several behavioural, morphological and locomotory characteristics that have evolved to facilitate dispersal of toads. We assessed a range of physiological characteristics associated with locomotory abilities in toads from the long-established, east coast of Australia, from the invasive front, and from a site in between these locations. We measured time to exhaustion and respiratory gases of toads exercising on a treadmill, time to recovery from exhaustion, blood properties (lactate, haematocrit, haemoglobin, red blood cell count, blood cell volume, and muscle properties associated with locomotion (activities of the enzymes citrate synthase and lactate dehydrogenase, and pH buffering capacity. None of the measured physiological parameters supported the hypothesis that toads from the invasive front possess physiological adaptations that facilitate dispersal compared to toads from areas colonised in the past. The strongest difference among the three groups of toads, time to exhaustion, showed exactly the opposite trend; toads from the long-established populations in the east coast had the longest time to exhaustion. Successful colonisers can employ many characteristics to facilitate their dispersal, so the extent to which behaviour, morphology and physiology co-evolve remains an interesting question. However, in the present case at least, behavioural adaptations do not appear to have altered the organism's underlying physiology.

  8. Cane toads lack physiological enhancements for dispersal at the invasive front in Northern Australia.

    Science.gov (United States)

    Tracy, Christopher R; Christian, Keith A; Baldwin, John; Phillips, Ben L

    2012-01-15

    Many invasive species have evolved behavioural and morphological characteristics that facilitate their dispersal into new areas, but it is unclear how selection on this level of the phenotype filters through to the underlying physiology. Cane toads have been dispersing westward across northern tropical Australia for more than 70 years. Previous studies of cane toads at the invasive front have identified several behavioural, morphological and locomotory characteristics that have evolved to facilitate dispersal of toads. We assessed a range of physiological characteristics associated with locomotory abilities in toads from the long-established, east coast of Australia, from the invasive front, and from a site in between these locations. We measured time to exhaustion and respiratory gases of toads exercising on a treadmill, time to recovery from exhaustion, blood properties (lactate, haematocrit, haemoglobin, red blood cell count, blood cell volume), and muscle properties associated with locomotion (activities of the enzymes citrate synthase and lactate dehydrogenase, and pH buffering capacity). None of the measured physiological parameters supported the hypothesis that toads from the invasive front possess physiological adaptations that facilitate dispersal compared to toads from areas colonised in the past. The strongest difference among the three groups of toads, time to exhaustion, showed exactly the opposite trend; toads from the long-established populations in the east coast had the longest time to exhaustion. Successful colonisers can employ many characteristics to facilitate their dispersal, so the extent to which behaviour, morphology and physiology co-evolve remains an interesting question. However, in the present case at least, behavioural adaptations do not appear to have altered the organism's underlying physiology.

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

    Science.gov (United States)

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

    2014-04-01

    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.

  10. Parasites of the Great Plains narrowmouth toad (Gastrophryne olivacea) from northern Texas.

    Science.gov (United States)

    McAllister, C T; Upton, S J

    1987-10-01

    Forty-nine adult and 14 immature Great Plains narrowmouth toads (Gastrophryne olivacea) from Johnson and Somervell Counties of northcentral Texas were examined for parasites. Sixty-four percent of the toads were infected with one or more species of parasites. New host records are reported for an isosporan similar to Isospora neos, and for Cylindrotaenia americana. The most common parasite in G. olivacea was the nematode, Cosmocercoides dukae. Prevalence was high among the adult G. olivacea (82%); however, none of the immature toads were infected.

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

    Directory of Open Access Journals (Sweden)

    Annemarie Ohler

    2016-01-01

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

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

    Science.gov (United States)

    Bartelt, Paul E.; Peterson, Charles R.; Klaver, Robert W.

    2004-01-01

    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.

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

    Data.gov (United States)

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

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

    Science.gov (United States)

    Phillips, Ben L; Shine, Richard

    2006-06-22

    Rapid environmental change due to human activities has increased rates of extinction, but some species may be able to adapt rapidly enough to deal with such changes. Our studies of feeding behaviour and physiological resistance to toxins reveal surprisingly rapid adaptive responses in Australian black snakes (Pseudechis porphyriacus) following the invasion of a lethally toxic prey item, the cane toad (Bufo marinus). Snakes from toad-exposed localities showed increased resistance to toad toxin and a decreased preference for toads as prey. Separate laboratory experiments suggest that these changes are not attributable to learning (we were unable to teach naive snakes to avoid toxic prey) or to acquired resistance (repeated sub-lethal doses did not enhance resistance). These results strongly suggest that black snake behaviour and physiology have evolved in response to the presence of toads, and have done so rapidly. Toads were brought to Australia in 1935, so these evolved responses have occurred in fewer than 23 snake generations.

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

    Science.gov (United States)

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

    2011-01-01

    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.

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

    Science.gov (United States)

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

    2012-08-24

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

  17. Biotic Resistance to an Alien Amphibian: Larval Competition between Japanese Frogs and Invasive Cane Toads.

    Directory of Open Access Journals (Sweden)

    Takashi Haramura

    Full Text Available Understanding negative effects of native species on introduced taxa may suggest novel ways to control the invasive species by enhancing such effects. Previous studies have reported that the larvae of invasive cane toads (Rhinella marina are suppressed by competition with the larvae of native anurans in Australia, but not in North America. We conducted laboratory trials to measure the effect of exposure to the larvae of Japanese frogs (Microhyla ornata, Fejervarya sakishimensis, Rhacophorus owstoni on rates of survival, growth and development of cane toad tadpoles in Ishigaki Island, in southern Japan. Survival rates were not affected by native species, but competition with Dicroglossids and Rhacophorids (but not Microhylids strongly reduced rates of growth and development in the tadpoles of cane toads. Dicroglossid tadpoles also reduced the body condition to toad tadpoles in addition to effects on SVL and mass. Encouraging populations of native frogs in toad-invaded areas of Japan thus may help to reduce the numbers of invasive cane toads.

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

    Science.gov (United States)

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

    2014-09-30

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

  19. Ticks, Amblyomma rotundatum (Acari: ixodidae), on toads, Chaunus schneideri and Chaunus granulosus (Anura: bufonidae), in northern Argentina.

    Science.gov (United States)

    Smith, Robert L; Schnack, Juan A; Schaefer, Eduardo F; Kehr, Arturo I

    2008-04-01

    This communication provides notes on 2 species of toads, Chaunus schneideri and Chaunus granulosus, infested with ixodid ticks, Amblyomma rotundatum, from the provinces of Corrientes and Formosa in northern Argentina. Chaunus schneideri is a new amphibian host record for A. rotundatum, a species previously reported to parasitize other anurans and also reptiles. We examined 74 ticks on 5 toads. All ticks were A. rotundatum; all adults were females, and all developmental stages were randomly attached to host body parts. Ticks remained attached to one of the toads for from 7 to 17 days after the host was captured. One toad, encumbered with 33 ticks, was moribund when found and died shortly thereafter.

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

    Directory of Open Access Journals (Sweden)

    K.P. Dinesh

    2014-10-01

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

  1. Influence of demography and environment on persistence in toad populations

    Science.gov (United States)

    Lambert, Brad A.; Schorr, Robert A.; Schneider, Scott C.; Muths, Erin L.

    2016-01-01

    Effective conservation of rare species requires an understanding of how potential threats affect population dynamics. Unfortunately, information about population demographics prior to threats (i.e., baseline data) is lacking for many species. Perturbations, caused by climate change, disease, or other stressors can lead to population declines and heightened conservation concerns. Boreal toads (Anaxyrus boreas boreas) have undergone rangewide declines due mostly to the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd), with only a few sizable populations remaining in the southern Rocky Mountains, USA, that are disease-free. Despite the apparent region-wide occurrence of Bd, our focal populations in central Colorado were disease free over a 14-year capture-mark-recapture study until the recent discovery of Bd at one of the sites. We used recapture data and the Pradel reverse-time model to assess the influence of environmental and site-specific conditions on survival and recruitment. We then forecast changes in the toad populations with 2 growth models; one using an average lambda value to initiate the projection, and one using the most recent value to capture potential effects of the incursion of disease into the system. Adult survival was consistently high at the 3 sites, whereas recruitment was more variable and markedly low at 1 site. We found that active season moisture, active season length, and breeding shallows were important factors in estimating recruitment. Population growth models indicated a slight increase at 1 site but decreasing trends at the 2 other sites, possibly influenced by low recruitment. Insight into declining species management can be gained from information on survival and recruitment and how site-specific environmental factors influence these demographic parameters. Our data are particularly useful because they provide baseline data on demographics in populations before a disease outbreak and enhance our ability to detect changes

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

    Data.gov (United States)

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

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

    Science.gov (United States)

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

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Gollmann Günter

    2011-03-01

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

  5. Cloning the sterol carrier protein 2 genes of Japanese toad (Bufo japonicus formosus) and Chinese toad (Bufo gargarizans) and its tissue expression analysis.

    Science.gov (United States)

    Ji, Yu-Cheng; Zhuge, Hui; Zhang, Shan-Shan; Zhang, Shu-Fang; Yang, Xian-Yu

    2014-09-01

    In this study, to clarify the bioactive polypeptides included in the skins and secretions of Bufo, we screened the Japanese toad (Bufo japonicus formosus) skin cDNA liary by colony polymerase chain reaction (PCR), and obtained a transcript of 1 075 bp consisting of 1 37 bp 5' untranslated region (UTR), 515 bp 3' UTR and a 423 bp open reading frame (ORF) encoding a polypeptide of 140 amino acid residues (GenBank accession number: KF359945). Homolog analysis showed a 70%-96% homology with sterol carrier protein-2 (SCP-2) present in other animals, which is implicated in lipid metabolism of other organisms. The gene SCP-2 of Chinese toad (B. gargarizans) was cloned from a first strand cDNA of Bufo skin (GenBank accession number: KF381341) via PCR, whose encoding polypeptide has only one amino acid difference from that of Japanese toad. Tissue distribution analysis showed that SCP-2 expressed in all organs tested, though in the liver and spleen it manifested lower expression than in other organs. These findings might indicate SCP-2 being one of the active ingredients in toad skin. These findings may in turn have implications for further drug development from traditional Chinese medicine sources.

  6. Chronic exposure to coal fly ash causes minimal changes in corticosterone and testosterone concentrations in male southern toads Bufo terrestris.

    Science.gov (United States)

    Ward, C K; Mendonça, M T

    2006-08-01

    More than 50% of the electricity in the United States is produced by coal-burning power plants. The byproduct of coal-burning plants is coal fly ash, which contains increased concentrations of trace metals and is disposed of in collection basins. Southern toads (Bufo terrestris) frequently use these basins for reproduction. Male toads were collected in spring 2001 and 2002 from an ash basin and a reference site and divided into four groups: toads collected at the control site and maintained on (1) control substrate and food or (2) ash and contaminated food and toads collected at the ash site and maintained in (3) control or (4) ash conditions. Blood was collected periodically during 5 months to determine testosterone and corticosterone concentrations. Reference to ash toads exhibited a significant, transient increase in corticosterone at 4 weeks, but neither corticosterone nor testosterone continued to increase beyond this time. In contrast, toads caught and maintained on ash did not exhibit increased corticosterone. Testosterone in these toads appeared to be unrelated to ash exposure. This unexpected lack of a corticosterone response and no effect on testosterone suggests that toads chronically exposed to trace metals can acclimate to a polluted environment, but they may still experience subtle long-term consequences.

  7. Function and cytology of the normal and autotransplanted pars distalis of the hypophysis in the toad Bufo bufo (L)

    NARCIS (Netherlands)

    Dongen, W.J. van; Barker Jørgensen, C.; Olesen Larsen, Lis; Rosenkilde, Per; Lofts, Brian; Oordt, P.G.W.J. van

    The functional activity of the pars distalis following heterotopic and homoiotopic autotransplantation has been studied in adult toads of both sexes in the spring, about a month after breeding, and in the autumn on toads with mature gonads. Gonadotropic Function. In males, the homoiotopic

  8. Chronic exposure to coal fly ash causes minimal changes in corticosterone and testosterone concentrations in male southern toads Bufo terrestris

    Energy Technology Data Exchange (ETDEWEB)

    Ward, C.K.; Mendonca, M.T. [Auburn University, Montgomery, AL (United States). Dept. of Biology

    2006-08-15

    More than 50% of the electricity in the United States is produced by coal-burning power plants. The byproduct of coal-burning plants is coal fly ash, which contains increased concentrations of trace metals and is disposed of in collection basins. Southern toads (Bufo terrestris) frequently use these basins for reproduction. Male toads were collected in spring 2001 and 2002 from an ash basin and a reference site and divided into four groups: toads collected at the control site and maintained on (1) control substrate and food or (2) ash and contaminated food and toads collected at the ash site and maintained in (3) control or (4) ash conditions. Blood was collected periodically during 5 months to determine testosterone and corticosterone concentrations. Reference to ash toads exhibited a significant, transient increase in corticosterone at 4 weeks, but neither corticosterone nor testosterone continued to increase beyond this time. In contrast, toads caught and maintained on ash did not exhibit increased corticosterone. Testosterone in these toads appeared to be unrelated to ash exposure. This unexpected lack of a corticosterone response and no effect on testosterone suggests that toads chronically exposed to trace metals can acclimate to a polluted environment, but they may still experience subtle long-term consequences.

  9. The Paraguayan Rhinella toad venom: Implications in the traditional medicine and proliferation of breast cancer cells.

    Science.gov (United States)

    Schmeda-Hirschmann, Guillermo; Gomez, Celeste Vega; Rojas de Arias, Antonieta; Burgos-Edwards, Alberto; Alfonso, Jorge; Rolon, Miriam; Brusquetti, Francisco; Netto, Flavia; Urra, Félix A; Cárdenas, César

    2017-03-06

    Toads belonging to genus Rhinella are used in Paraguayan traditional medicine to treat cancer and skin infections. The objective of the study was to determine the composition of venoms obtained from three different Paraguayan Rhinella species, to establish the constituents of a preparation sold in the capital city of Paraguay to treat cancer as containing the toad as ingredient, to establish the effect of the most active Rhinella schneideri venom on the cell cycle using human breast cancer cells and to assess the antiprotozoal activity of the venoms. The venom obtained from the toads parotid glands was analyzed by HPLC-MS-MS. The preparation sold in the capital city of Paraguay to treat cancer that is advertised as made using the toad was analyzed by HPLC-MS-MS. The effect of the R. schneideri venom and the preparation was investigated on human breast cancer cells. The antiprotozoal activity was evaluated on Leishmania braziliensis, L. infantum and murine macrophages. From the venoms of R. ornata, R. schneideri and R. scitula, some 40 compounds were identified by spectroscopic and spectrometric means. Several minor constituents are reported for the first time. The preparation sold as made from the toad did not contained bufadienolides or compounds that can be associated with the toad but plant compounds, mainly phenolics and flavonoids. The venom showed activity on human breast cancer cells and modified the cell cycle proliferation. The antiprotozoal effect was higher for the R. schneideri venom and can be related to the composition and relative ratio of constituents compared with R. ornata and R. scitula. The preparation sold in the capital city of Paraguay as containing the toad venom, used popularly to treat cancer did not contain the toad venom constituents. Consistent with this, this preparation was inactive on proliferation of human breast cancer cells. In contrast, the toad venoms of Rhinella species altered the cell cycle progression, affecting the

  10. Alfaxalone versus alfaxalone-dexmedetomidine anaesthesia by immersion in oriental fire-bellied toads (Bombina orientalis).

    Science.gov (United States)

    Adami, Chiara; d'Ovidio, Dario; Casoni, Daniela

    2016-05-01

    To determine a dexmedetomidine concentration, to be added to an alfaxalone-based bath solution, that will enhance the anaesthetic and analgesic effects of alfaxalone; and to compare the quality of anaesthesia and analgesia provided by immersion with either alfaxalone alone or alfaxalone with dexmedetomidine in oriental fire-bellied toads (Bombina orientalis). Pilot study followed by a prospective, randomized, experimental trial. Fourteen oriental fire-bellied toads. The pilot study aimed to identify a useful dexmedetomidine concentration to be added to an anaesthetic bath containing 20 mg 100 mL(-1) alfaxalone. Thereafter, the toads were assigned to one of two groups, each comprising eight animals, to be administered either alfaxalone (group A) or alfaxalone-dexmedetomidine (group AD). After immersion for 20 minutes, the toads were removed from the anaesthetic bath and the righting, myotactic and nociceptive reflexes, cardiopulmonary variables and von Frey filaments threshold were measured at 5 minute intervals and compared statistically between groups. Side effects and complications were noted and recorded. In the pilot study, a dexmedetomidine concentration of 0.3 mg 100 mL(-1) added to the alfaxalone-based solution resulted in surgical anaesthesia. The toads in group AD showed higher von Frey thresholds and lower nociceptive withdrawal reflex scores than those in group A. However, in group AD, surgical anaesthesia was observed in two out of eight toads only, and induction of anaesthesia was achieved in only 50% of the animals, as compared with 100% of the toads in group A. The addition of dexmedetomidine to an alfaxalone-based solution for immersion anaesthesia provided some analgesia in oriental fire-bellied toads, but failed to potentiate the level of unconsciousness and appeared to lighten the depth of anaesthesia. This limitation renders the combination unsuitable for anaesthetizing oriental fire-bellied toads for invasive procedures. © 2015

  11. Invasive toads shift predator-prey densities in animal communities by removing top predators.

    Science.gov (United States)

    Doody, J Sean; Soanes, Rebekah; Castellano, Christina M; Rhind, David; Green, Brian; McHenry, Colin R; Clulow, Simon

    2015-09-01

    Although invasive species can have substantial impacts on animal communities, cases of invasive species facilitating native species by removing their predators have rarely been demonstrated across vertebrate trophic linkages. The predictable spread of the invasive cane toad (Rhinella marina), however, offered a unique opportunity to quantify cascading effects. In northern Australia, three species of predatory monitor lizards suffered severe population declines due to toad-induced lethal toxic ingestion (yellow-spotted monitor (Varanus panoptes), Mertens' water monitor (V. mertensi), Mitchell's water monitor (V. mitchelli). We, thus, predicted subsequent increases in the abundance and recruitment of prey species due to the reduction of those predators. Toad-induced population-level declines in the water monitor species approached 50% over a five-year period spanning the toad invasion, apparently causing fledging success of the Crimson Finch (Neochmia.phaeton) to increase from 55% to 81%. The consensus of our original and published long-term data is that invasive cane toads are causing predators to lose a foothold on top-down regulation of their prey, triggering shifts in the relative densities of predator and prey in the Australian tropical savannah ecosystem.

  12. Measuring Energetics and Behaviour Using Accelerometry in Cane Toads Bufo marinus

    Science.gov (United States)

    Halsey, Lewis G.; White, Craig R.

    2010-01-01

    Cane toads Bufo marinus were introduced to Australia as a control agent but now have a rapidly progressing invasion front and damage new habitats they enter. Predictive models that can give expansion rates as functions of energy supply and feeding ground distribution could help to maximise control efficiency but to date no study has measured rates of field energy expenditure in an amphibian. In the present study we used the accelerometry technique to generate behavioural time budgets and, through the derivation of ODBA (overall dynamic body acceleration), to obtain estimates of energetics in free ranging cane toads. This represents the first time that accelerometers have been used to not only quantify the behaviour of animals but also assign to those behaviours rates of energy expenditure. Firstly, laboratory calibrations between ODBA and metabolic rate were obtained and used to generate a common prediction equation for the subject toads (R2 = 0.74). Furthermore, acceleration data recorded during different behaviours was studied to ascertain threshold values for objectively defining behaviour categories. Importantly, while subsequent accelerometer field deployments were relatively short they agreed with previous studies on the proportion of time that cane toads locomote yet suggest that the metabolic rate of cane toads in the wild may sometimes be considerably higher than might be assumed based on data for other species. PMID:20422048

  13. Antitumor activity of extracts and compounds from the skin of the toad Bufo bufo gargarizans Cantor.

    Science.gov (United States)

    Qi, Fanghua; Li, Anyuan; Inagaki, Yoshinori; Kokudo, Norihiro; Tamura, Sumihito; Nakata, Munehiro; Tang, Wei

    2011-03-01

    The skin of the toad Bufo bufo gargarizans Cantor is known to be rich in bufadienolides, peptides and alkaloids. It has been found to be a source of some extracts and biologically active compounds with antitumor activity. Cinobufacini (Huachansu), a Chinese medicine prepared from the dried toad skin, has been widely used in clinical therapy for various cancers in China. Bufadienolides, such as bufalin, cinobufagin, resibufogenin, and telocinobufagin, are the major active compounds derived from the toad skin. They are the maker biologically active compounds of cinobufagin while the antitumor activity of cinobufagin may be due to this kind of components. Experimental research has suggested that cinobufacini and its active compounds (e.g. bufalin and cinobufagin) exhibit significant antitumor activity, including inhibition of cell proliferation, induction of cell differentiation, induction of apoptosis, disruption of the cell cycle, inhibition of cancer angiogenesis, reversal of multi-drug resistance, and regulation of the immune response. Clinical data have indicated that cinobufacini may have effective anticancer activity with low toxicity and few side effects. Data to date suggest it may also enhance quality of life for patients with cancer. Thus, this review briefly summarizes recent studies on the anticancer activity of cinobufacini and some of its active compounds from the skin of the toad Bufo bufo gargarizans Cantor. This might provide additional evidence for further study of the extracts and active compounds from the toad skin in cancer treatment. Copyright © 2010 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Lewis G Halsey

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

  15. Effects of invasion history on physiological responses to immune system activation in invasive Australian cane toads.

    Science.gov (United States)

    Selechnik, Daniel; West, Andrea J; Brown, Gregory P; Fanson, Kerry V; Addison, BriAnne; Rollins, Lee A; Shine, Richard

    2017-01-01

    The cane toad (Rhinella marina) has undergone rapid evolution during its invasion of tropical Australia. Toads from invasion front populations (in Western Australia) have been reported to exhibit a stronger baseline phagocytic immune response than do conspecifics from range core populations (in Queensland). To explore this difference, we injected wild-caught toads from both areas with the experimental antigen lipopolysaccharide (LPS, to mimic bacterial infection) and measured whole-blood phagocytosis. Because the hypothalamic-pituitary-adrenal axis is stimulated by infection (and may influence immune responses), we measured glucocorticoid response through urinary corticosterone levels. Relative to injection of a control (phosphate-buffered saline), LPS injection increased both phagocytosis and the proportion of neutrophils in the blood. However, responses were similar in toads from both populations. This null result may reflect the ubiquity of bacterial risks across the toad's invaded range; utilization of this immune pathway may not have altered during the process of invasion. LPS injection also induced a reduction in urinary corticosterone levels, perhaps as a result of chronic stress.

  16. Thermal ecology of the post-metamorphic Andean toad (Rhinella spinulosa) at elevation in the monte desert, Argentina.

    Science.gov (United States)

    Sanabria, Eduardo A; Rodríguez, César Y; Vergara, Cristina; Ontivero, Emanuel; Banchig, Mariana; Navas, Ana L; Herrera-Morata, Mario A; Quiroga, Lorena B

    2015-08-01

    Rhinella spinulosa is an anuran toad species distributed latitudinal and altitudinal (1200-5000m) from Peru to Argentina, inhabiting mountain valleys in the Andes. Considering the broad range of habitats where they live, it is important to understand the thermal physiological mechanisms, thermal tolerances and physiological adaptations for surviving in rigorous environments. We investigated the thermal parameters (field body temperature, selected body temperature, locomotor performance in field and laboratory conditions, and thermal extremes) during diurnal activity for a population of juvenile, post-metamorphosed toads (Rhinella spinulosa) from the Monte Desert of San Juan, Argentina. Post-metamorphic toads are active from approximately 1100-1900 (in contrast to nocturnal adult toads). Our findings show that these toads have a wide thermal tolerance range, ranging from a critical thermal maximum of 36.9°C to crystallization temperatures below 0°C. During their active period, toads always showed suboptimal thermal conditions for locomotion. Despite the suboptimal condition for the locomotion, diurnal activity is likely to confer thermal advantages, allowing them to search for food and increase digestion and growth rates. We also found that the toads are capable of super-cooling, which prevents mortality from freezing when the environmental temperatures drop below 0°C. The environmental temperatures are below zero at night, when toads are inactive and take refuge under rocks. In summary, this toad population demonstrates high thermal plasticity, as shown by a relatively high level of activity sustained over a wide range of ambient temperature (~35°C). These thermal adaptations allow this species of juvenile toads to inhabit a wide range of altitudes and latitudes. Copyright © 2015. Published by Elsevier Ltd.

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

    Directory of Open Access Journals (Sweden)

    Rosie D Salazar

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

  18. Multiple paternity in a viviparous toad with internal fertilisation.

    Science.gov (United States)

    Sandberger-Loua, Laura; Feldhaar, Heike; Jehle, Robert; Rödel, Mark-Oliver

    2016-08-01

    Anurans are renowned for a high diversity of reproductive modes, but less than 1 % of species exhibit internal fertilisation followed by viviparity. In the live-bearing West African Nimba toad (Nimbaphrynoides occidentalis), females produce yolk-poor eggs and internally nourish their young after fertilisation. Birth of fully developed juveniles takes place after 9 months. In the present study, we used genetic markers (eight microsatellite loci) to assign the paternity of litters of 12 females comprising on average 9.7 juveniles. In 9 out of 12 families (75 %), a single sire was sufficient; in three families (25 %), more than one sire was necessary to explain the observed genotypes in each family. These findings are backed up with field observations of male resource defence (underground cavities in which mating takes place) as well as coercive mating attempts, suggesting that the observed moderate level of multiple paternity in a species without distinct sperm storage organs is governed by a balance of female mate choice and male reproductive strategies.

  19. Success of capture of toads improved by manipulating acoustic characteristics of lures.

    Science.gov (United States)

    Muller, Benjamin J; Schwarzkopf, Lin

    2017-11-01

    Management of invasive vertebrates is a crucial component of conservation. Trapping reproductive adults is often effective for control, and modification of traps may greatly increase their attractiveness to such individuals. Cane toads (Rhinella marina) are invasive, and males use advertisement vocalisations to attract reproductive females. In amphibians, including toads, specific structural parameters of calls (e.g. dominant frequency and pulse rate) may be attractive to females. Some cane toad traps use an artificial advertisement vocalisation to attract toads. We determined whether variation of the call's parameters (volume, dominant frequency and pulse rate) could increase the capture rate of gravid females. Overall, traps equipped with loud calls (80 dB at 1 m) caught significantly more toads, and proportionally more gravid females, than traps with quiet calls (60 dB at 1 m), and traps with low dominant frequency calls caught more gravid females than traps with median frequency calls. Traps with high pulse rate calls attracted more females than traps with low pulse rate calls. Approximately 91% of the females trapped using a low frequency and high pulse rate combination call were gravid, whereas in traps using a call with population median parameters only approximately 75% of captured females were gravid. Calls that indicated large-bodied males (low frequency) with high energy reserves (high pulse rate) are often attractive to female anurans and were effective lures for female toads in our study. The design of future trapping regimes should account for behavioural preferences of the target sex. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  20. Comparison of toad venoms from different Bufo species by HPLC and LC-DAD-MS/MS.

    Science.gov (United States)

    Gao, Huimin; Zehl, Martin; Leitner, Alexander; Wu, Xiyan; Wang, Zhimin; Kopp, Brigitte

    2010-09-15

    Toad venom, called Chansu in China, has been widely used for the treatment of heart failure, sores, pains, and various cancers for a long time in clinic. The aim of the study is to investigate the chemical differences among a variety of toad venoms from different geographic locations and related Bufo species. Ten batches of commercial toad venom collected from different regions in China, one batch of fresh toad venom obtained from Bufo bufo gargarizans, and six batches of related Bufo species were analyzed by HPLC and LC-DAD-MS/MS. Individual components were identified by comparison of retention times, UV spectra, and mass spectra with authentic compounds, standard addition, as well as summarized MS fragmentation rules. Based on the profile of identified constituents and the content of cinobufagin and resibufogenin, the chemical differences observed among different samples are discussed. Overall, 43 compounds were identified in the methanolic extracts of the different samples of toad venom. Besides of suberoyl arginine, several free bufadienolides, bufadienolide sulfates, and suberoyl esters of bufadienolides were found. The total amounts of cinobufagin and resibufogenin, which are the only two control markers according to the current Chinese Pharmacopoeia, varied widely from 0.7% to 10.9% in the commercial Chansu samples collected in the different locations in China. Low levels of resibufogenin, but no cinobufagin was observed in the samples from Bufo melanosticus and Bufo marinus, and even neither of both compounds was found in the sample from Bufo viridis. The chemical profiles of the different commercial and collected toad venoms from related Bufo species differed significantly, not only in the absolute and relative contents, but also in the number and type of the constituents. The main reason for this variation are species-specific differences, but additional factors, such as the harvest and post-harvest processing, and adaption to environmental factors in

  1. A New Indole Alkaloid from the Toad Venom of Bufo bufo gargarizans.

    Science.gov (United States)

    Dai, Ying-Hui; Shen, Bo; Xia, Ming-Yu; Wang, An-Dong; Chen, Yu-Lin; Liu, Dong-Chun; Wang, Dong

    2016-03-16

    A new indole alkaloid named bufobutarginine (1), along with three known bufotenines, namely, serotonin (2), bufotenidine (3), and bufotenine (4), were isolated from the water extract of toad venom. Their structures were elucidated by spectral methods. This is the first time that arginine has been found to be involved in the biosynthesis of bufotenines in parotid of toad. The cytotoxic activities of these compounds have been assayed against A375 and A549 cell lines by the MTT method; however, they showed no cytotoxic activities.

  2. Toxicity of mine drainage to embryonic and larval boreal toads (Bufonidae: Bufo boreas)

    Energy Technology Data Exchange (ETDEWEB)

    Porter, K.R.; Hakanson, D.E.

    1976-05-17

    Chemical analyses and bioassays of mine drainage were made to determine if it could be a factor accounting for the absence of amphibians from Clear Creek County, Colorado. The concentrations of hydrogen ion, iron, copper and zinc in the drainage were all individually much greater than the tolerance levels of premetamorphic toads. The lethality of the drainage was found to be of such a magnitude that it required diluting approximately one thousand times before larvae could survive in it. Boreal toad (Bufo boreas) larvae are more resistant to acidity than most fish but are very similar to other anuran larvae and salmonids in their sensitivity to copper and zinc. (auth)

  3. Species limits in the Andean toad genus Osornophryne (Bufonidae).

    Science.gov (United States)

    Páez-Moscoso, Diego J; Guayasamin, Juan M

    2012-12-01

    As Darwin observed, the differentiation among varieties, subspecies, and species seems, often times, arbitrary. Nowadays, however, novel tools provide the possibility of testing hypotheses of species. Using the Andean toad genus Osornophryne, we address the following questions: (1) How many species are within the genus? (2) Are morphological and molecular traits congruent when delimiting species? (3) Which morphological traits are the most divergent among species? We use recently developed methods for testing species boundaries and relationships using a multilocus data set consisting of two mitochondrial genes (12S, 16S; 1647bp aligned matrix), one exon (RAG-1; 923 aligned matrix), and one intron (RPL3Int5; 1410bp aligned matrix). As another line of evidence for species delimitation, we integrated analyses of 12 morphometric variables and 10 discrete traits commonly used in amphibian systematics. The molecular and morphological approaches support the validity of most of the described species in Osornophryne. We find, however, contradictory lines of evidence regarding the status of O. angel. Within O. guacamayo, we found a genetically divergent population that, we argue, represents a new species. We consider that O. bufoniformis represents a species complex that deserves further study. We highlight the importance of incorporating morphological data when delimiting species, especially for lineages that have a recent origin and have not achieved reciprocal monophyly in molecular phylogenies. Finally, the most divergent morphological traits among Osornophryne species are associated with locomotion (finger, toes and limbs) and feeding (head), suggesting an association between morphology and the ecological habits of the species. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Effects of invasion history on physiological responses to immune system activation in invasive Australian cane toads

    Directory of Open Access Journals (Sweden)

    Daniel Selechnik

    2017-10-01

    Full Text Available The cane toad (Rhinella marina has undergone rapid evolution during its invasion of tropical Australia. Toads from invasion front populations (in Western Australia have been reported to exhibit a stronger baseline phagocytic immune response than do conspecifics from range core populations (in Queensland. To explore this difference, we injected wild-caught toads from both areas with the experimental antigen lipopolysaccharide (LPS, to mimic bacterial infection and measured whole-blood phagocytosis. Because the hypothalamic-pituitary-adrenal axis is stimulated by infection (and may influence immune responses, we measured glucocorticoid response through urinary corticosterone levels. Relative to injection of a control (phosphate-buffered saline, LPS injection increased both phagocytosis and the proportion of neutrophils in the blood. However, responses were similar in toads from both populations. This null result may reflect the ubiquity of bacterial risks across the toad’s invaded range; utilization of this immune pathway may not have altered during the process of invasion. LPS injection also induced a reduction in urinary corticosterone levels, perhaps as a result of chronic stress.

  5. Bufospirostenin A and Bufogargarizin C, Steroids with Rearranged Skeletons from the Toad Bufo bufo gargarizans.

    Science.gov (United States)

    Tian, Hai-Yan; Ruan, Li-Jun; Yu, Tong; Zheng, Qing-Fei; Chen, Nan-Hao; Wu, Rui-Bo; Zhang, Xiao-Qi; Wang, Lei; Jiang, Ren-Wang; Ye, Wen-Cai

    2017-04-28

    Bufospirostenin A (1) and bufogargarizin C (2), two novel steroids with rearranged A/B rings, were isolated from the toad Bufo bufo gargarizans. Compound 1 represents the first spirostanol found in animals. Compound 2 is an unusual bufadienolide with a cycloheptatriene B ring. Their structures were elucidated by spectroscopic analysis, single crystal X-ray diffraction analysis, and computational calculations.

  6. Selection of diet by metamorphic and juvenile western toads (Bufo boreas) in northeastern Oregon

    Science.gov (United States)

    Evelyn L Bull; Jane L. Hayes

    2009-01-01

    The decline of Bufo boreas, the Western Toad, in portions of its range has accentuated the need for more complete information on all life stages of this species. Our objectives were to describe the diet of recently metamorphosed and juvenile (one-year old) B. boreas and then compare it to the available arthropods. Metamorphs (n...

  7. Effect of Cortisol on Plasma Lactate Levels following Cortisolinduced Hyperglycaemia in Common African Toad, Bufo regularis.

    Science.gov (United States)

    Isehunwa, G O; Oladun, O T; Akpan, J E; Alada, A R A

    2017-06-30

    Previous studies in man have shown that cortisol induces hyperglycemia through gluconeogenesis. However,the metabolic substrates involved in cortisol-induced hyperglycemia and the role of adrenergic receptors in lactate productionin toads have not been well studied. This study investigated the effects of adrenergic receptor blockers in cortisol-inducedhyperglycemia and blood lactate levels in the common African toad (Bufo regularis). Each toad was fasted and anaesthetizedwith sodium thiopentone given intraperitoneally (50mg/kg/i.p). The animals (control) received 0.7% amphibian saline whileanimals (untreated) received cortisol intravenously (50µg/kg/i.v). In pre-treatment groups, animals received propanolol (0.5mg/kg/i.v), prazosin (0.2 mg/kg/i.v) and combination of propanolol (0.5mg/kg/i.v) and prazosin (0.2 mg/kg/i.v) respectivelyfollowed by administration of cortisol 50µg/kg/i.v. Thereafter, blood samples were collected for estimation of glucose andlactate using the modified glucose oxidase method and colorimetric method respectively. Cortisol caused significant increase in blood glucose level ((pbufo regularis. The betaadrenergic receptors are involved in the use of lactate to induce cortisol hyperglycemia in the Common African toad Buforegularis.

  8. Population traits of the burrowing toad Rhinella fernandezae (Gallardo, 1957) (Anura, Bufonidae).

    Science.gov (United States)

    Sanchez, L C; Busch, M

    2008-02-01

    Size distribution, sex ratio and use of burrows of the burrowing toad Rhinella fernandezae were studied in Buenos Aires province, Argentina. Two sites separated by approximately 300 m were studied: one was a road next to a swamp, and the other a garden of a country house located further from the swamp. We identified toad burrows, and individuals were sexed, measured and given an individual mark. Burrows were examined in subsequent months after the first sampling to assess the presence of toads. We found significant differences in the size distribution between areas, being the proportion of juveniles greater at the site next to the swamp where the reproduction of the species was observed. This result may suggest that the site located near to the swamp functions as a source habitat of individuals that migrate to the other site, where recruitment would be very scarce. Sex proportion of adults did not differ from 1:1 in neither the total population nor in each site, suggesting that there was not differential mortality by sex. Some toads changed burrows throughout the study period, but there were not differences in the frequency of change between adults and juveniles.

  9. 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...

  10. Population dynamics of the critically endangered toad Atelopus cruciger and the fungal disease chytridiomycosis.

    Directory of Open Access Journals (Sweden)

    Margarita Lampo

    Full Text Available Harlequin toads (Atelopus are among the most severely impacted amphibians by the emergence of chytridiomycosis, a fungal disease caused by the pathogen Batrachochytrium dendrobatidis (Bd. Many species disappeared while others suffered drastic contractions of their geographic distribution to lower altitudes. A diminished virulence of Bd in warm habitats was proposed to explain the survival of lowland populations of harlequin toads (i.e. thermal refuge hypothesis. To understand the mechanisms that allow some populations to reach an endemic equilibrium with this pathogen, we estimated demographic and epidemiological parameters at one remnant population of Atelopus cruciger in Venezuela using mark-recapture data from 2007-2013. We demonstrated that Bd is highly virulent for A. cruciger, increasing the odds of dying of infected adults four times in relation to uninfected ones and reducing the life expectancy of reproductive toads to a few weeks. Despite an estimated annual loss of 18% of the reproductive population due to Bd-induced mortality, this population has persisted in an endemic equilibrium for the last decade through the large recruitment of healthy adults every year. Given the high vulnerability of harlequin toads to Bd in lowland populations, thermal refuges need to be redefined as habitats of reduced transmission rather than attenuated virulence.

  11. Invader immunology: invasion history alters immune system function in cane toads (Rhinella marina) in tropical Australia.

    Science.gov (United States)

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

    2015-01-01

    Because an individual's investment into the immune system may modify its dispersal rate, immune function may evolve rapidly in an invader. We collected cane toads (Rhinella marina) from sites spanning their 75-year invasion history in Australia, bred them, and raised their progeny in standard conditions. Evolved shifts in immune function should manifest as differences in immune responses among the progeny of parents collected in different locations. Parental location did not affect the offspring's cell-mediated immune response or stress response, but blood from the offspring of invasion-front toads had more neutrophils, and was more effective at phagocytosis and killing bacteria. These latter measures of immune function are negatively correlated with rate of dispersal in free-ranging toads. Our results suggest that the invasion of tropical Australia by cane toads has resulted in rapid genetically based compensatory shifts in the aspects of immune responses that are most compromised by the rigours of long-distance dispersal. © 2014 John Wiley & Sons Ltd/CNRS.

  12. Morphological and genetic differentiation of Bufo toads: two cryptic species in Western Europe (Anura, Bufonidae)

    NARCIS (Netherlands)

    Arntzen, J.W.; McAtear, J.; Recuero, E.; Ziermann, J.M.; Ohler, A.; Alphen, van J.; Martínez-Solano, I.

    2013-01-01

    The Common toad Bufo bufo sensu lato is a widespread, morphologically conserved taxon. Recent studies have uncovered deep genetic differentiation between population groups, highlighting the need to revise the current taxonomy of the group and recognize additional species. Here we investigate

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

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Rasmussen, B E

    1983-01-01

    The Cl- -current through toad skin epithelium depends on the potential in a way consistent with a potential-controlled Cl- permeability. Computer analysis of the Koefoed-Johnsen Ussing two-membrane model provided with constant membrane permeabilities indicates that the voltage- and time-dependent...

  14. Etomidate anaesthesia by immersion in oriental fire-bellied toads (Bombina orientalis).

    Science.gov (United States)

    d'Ovidio, D; Spadavecchia, C; Angeli, G; Adami, C

    2015-10-01

    The objective of the present study was to evaluate the efficacy and the safety of etomidate anaesthesia by immersion technique in Bombina orientalis. The study comprised two phases. The first phase was carried out to identify the etomidate concentration capable of producing anaesthetic induction, as well as surgical anaesthesia, in the toads. The second phase was aimed at testing that concentration in eight additional animals. Etomidate administered via immersion at a concentration of 37.5 mg/L produced effective anaesthesia in oriental fire-bellied toads. The average duration of surgical anaesthesia was 20 min. All the toads enrolled in the study survived the anaesthesia and long-term complications did not occur. However, undesired side-effects, namely itching, myoclonus and prolonged recovery, were noticed during the perianaesthetic period. The authors concluded that etomidate anaesthesia by immersion, at a concentration of 37.5 mg/L, is suitable in oriental fire-bellied toads and produces anaesthesia of a depth and duration that is sufficient to allow the completion of various experimental procedures, without resulting in lethal complications. However, the occurrence of undesired side-effects opens a debate on the safety of this anaesthetic technique, and imposes the need for further investigation prior to proposing the latter for routine laboratory practice. © The Author(s) 2015.

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

    Science.gov (United States)

    Christina T. Liang; Thomas J. Stohlgren

    2011-01-01

    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...

  16. Fine-scale habitat characteristics related to occupancy of the Yosemite Toad, Anaxyrus canorus

    Science.gov (United States)

    Christina T. Liang; Robert L. Grasso; Julie J. Nelson-Paul; Kim E. Vincent; Amy J. Lind

    2017-01-01

    Fine-scale habitat information can provide insight into species occupancy and persistence that is not apparent at the landscape-scale. Such information is particularly important for rare species that are experiencing population declines, such as the threatened Yosemite Toad (Anaxyrus canorus). Our study examined differences in physical...

  17. 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...

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

    Directory of Open Access Journals (Sweden)

    Felicity B.L. Nelson

    2015-12-01

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

  19. Invasive species as drivers of evolutionary change: cane toads in tropical Australia.

    Science.gov (United States)

    Shine, Richard

    2012-02-01

    The arrival of an invasive species can have wide-ranging ecological impacts on native taxa, inducing rapid evolutionary responses in ways that either reduce the invader's impact or exploit the novel opportunity that it provides. The invasion process itself can cause substantial evolutionary shifts in traits that influence the invader's dispersal rate (via both adaptive and non-adaptive mechanisms) and its ability to establish new populations. I briefly review the nature of evolutionary changes likely to be set in train by a biological invasion, with special emphasis on recent results from my own research group on the invasion of cane toads (Rhinella marina) through tropical Australia. The toads' invasion has caused evolutionary changes both in the toads and in native taxa. Many of those changes are adaptive, but others may result from non-adaptive evolutionary processes: for example, the evolved acceleration in toad dispersal rates may be due to spatial sorting of dispersal-enhancing genes, rather than fitness advantages to faster-dispersing individuals. Managers need to incorporate evolutionary dynamics into their conservation planning, because biological invasions can affect both the rates and the trajectories of evolutionary change.

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

    DEFF Research Database (Denmark)

    Harck, A F; Larsen, Erik Hviid

    1986-01-01

    The isolated toad (Bufo bufo) skin was mounted under voltage-clamp conditions in a chamber shown to cause no significant edge damage. The serosal side of the skin was bathed with NaCl-Ringer's, and the passive voltage-sensitive anion conductance studied in its fully voltage activated state, V = -...

  1. Population dynamics of the critically endangered toad Atelopus cruciger and the fungal disease chytridiomycosis

    Science.gov (United States)

    Señaris, Celsa; García, Carmen Zulay

    2017-01-01

    Harlequin toads (Atelopus) are among the most severely impacted amphibians by the emergence of chytridiomycosis, a fungal disease caused by the pathogen Batrachochytrium dendrobatidis (Bd). Many species disappeared while others suffered drastic contractions of their geographic distribution to lower altitudes. A diminished virulence of Bd in warm habitats was proposed to explain the survival of lowland populations of harlequin toads (i.e. thermal refuge hypothesis). To understand the mechanisms that allow some populations to reach an endemic equilibrium with this pathogen, we estimated demographic and epidemiological parameters at one remnant population of Atelopus cruciger in Venezuela using mark-recapture data from 2007–2013. We demonstrated that Bd is highly virulent for A. cruciger, increasing the odds of dying of infected adults four times in relation to uninfected ones and reducing the life expectancy of reproductive toads to a few weeks. Despite an estimated annual loss of 18% of the reproductive population due to Bd-induced mortality, this population has persisted in an endemic equilibrium for the last decade through the large recruitment of healthy adults every year. Given the high vulnerability of harlequin toads to Bd in lowland populations, thermal refuges need to be redefined as habitats of reduced transmission rather than attenuated virulence. PMID:28570689

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

    Science.gov (United States)

    David S. Pilliod; Erin Muths; Rick D. Scherer; Paul E. Bartelt; Paul Stephen Corn; Blake R. Hossack; Brad A. Lambert; Rebecca McCaffery; Christopher Gaughan

    2010-01-01

    Chytridiomycosis is linked to the worldwide decline of amphibians, yet little is known about the demographic effects of the disease. We collected capture-recapture data on three populations of boreal toads (Bufo boreas [Bufo = Anaxyrus]) in the Rocky Mountains (U.S.A.). Two of the populations were infected with chytridiomycosis and one was not. We examined the effect...

  3. Phalangeal bone anomalies in the European common toad Bufo bufo from polluted environments.

    Science.gov (United States)

    Kaczmarski, Mikołaj; Kolenda, Krzysztof; Rozenblut-Kościsty, Beata; Sośnicka, Wioletta

    2016-11-01

    Every spring, many of amphibians are killed by motor vehicles on roads. These road-killed animals can be used as valuable material for non-invasive studies showing the effect of environmental pollution on amphibian populations. The aims of our research were to check whether the phalanges of road-killed toads may be useful as material for histological analysis, and whether various degrees of human impact influence the level in bone abnormalities in the common toad. We also examined whether the sex and age structure of toads can differ significantly depending in the different sites. We chose three toad breeding sites where road-killed individuals had been observed: near the centre of a city, the outskirts of a city, and a rural site. We collected dead individuals during spring migration in 2013. The sex of each individual was determined and the toes were used to determine age using the skeletochronology method. While performing age estimates, we looked for abnormalities in relation to normal bone tissue structure. In urban site, females dominate males (sex ratio 2.6:1), but in populations from rural and semi-urban sites, sex ratio was reverse (1:2.2 and 1:1.4, respectively). However, we did not find any significant differences between age structure of all populations (average age of each population: approximately 4 years). We observed abnormalities in more than 80 % of all toads from the city, compared to approximately 20 % from the rural and semi-urban sites. In particular, we found hypertrophic bone cells, misaligned intercellular substance, and irregular outer edges of bones. We suggest that these malformations are caused by different pollution, e.g. with heavy metals.

  4. Low doses of urethane effectively inhibit spinal seizures evoked by sudden cooling of toad isolated spinal cord

    Energy Technology Data Exchange (ETDEWEB)

    Pina-crespo, J.C.; Dalo, N.L. (Univ. Centroccidental Lisandro Alvarado, Barquisimeto (Venezuela))

    1992-01-01

    The effect of low doses of urethane on three phases of spinal seizures evoked by sudden cooling (SSSC) of toad isolated spinal cord was studied. In control toads, SSSC began with a latency of 91[plus minus]3 sec exhibiting brief tremors, followed by clonic muscle contractions and finally reaching a tonic contraction. The latency of onset of seizures was significantly enhanced. The tonic phase was markedly abolished in toads pretreated intralymphaticaly with 0.15 g/kg of urethane. Tremors were the only phase observed in 55% of toads that received doses of 0.2 g/kg, and a total blockage of seizures was seen after doses of 0.25 g/kg of urethane in 50% of the preparations. A possible depressant effect of urethane on transmission mediated by excitatory amino acids is suggested.

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

    Data.gov (United States)

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

  6. Use of local visual cues for spatial orientation in terrestrial toads (Rhinella arenarum): The role of distance to a goal.

    Science.gov (United States)

    Daneri, M Florencia; Casanave, Emma B; Muzio, Rubén N

    2015-08-01

    The use of environmental visual cues for navigation is an ability present in many groups of animals. The effect of spatial proximity between a visual cue and a goal on reorientation in an environment has been studied in several vertebrate groups, but never previously in amphibians. In this study, we tested the use of local visual cues (beacons) to orient in an open field in the terrestrial toad (Rhinella arenarum). Experiment 1 showed that toads could orient in space using 2 cues located near the rewarded container. Experiment 2 used only 1 cue placed at different distances to the goal and revealed that learning speed was affected by the proximity to the goal (the closer the cue was to the goal, the faster toads learned its location). Experiment 3 showed that the position of a cue results in a different predictive value. Toads preferred cues located closer to the goal more than those located farther away as a reference for orientation. Present results revealed, for the first time, that (a) toads can learn to orient in an open space using visual cues, and that (b) the effect of spatial proximity between a cue and a goal, a learning phenomenon previously observed in other groups of animals such as mammals, birds, fish, and invertebrates, also affects orientation in amphibians. Thus, our results suggest that toads are able to employ spatial strategies that closely parallel those described in other vertebrate groups, supporting an early evolutionary origin for these spatial orientation skills. (c) 2015 APA, all rights reserved).

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-12-01

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

  8. Effects of Cr3+ ions on electrophysiological parameters of isolated skin of toad Pleurodema thaul

    Directory of Open Access Journals (Sweden)

    Luis Guzman Jofre

    2016-01-01

    Full Text Available In view of the toxicity of chromium (Cr3+ ions, it was explored the damaging effects that this ion could induce in cell membranes. The measurement of the effects induced by Cr3+ ions on electrophysiological parameters of short-circuit current and on the potential difference were investigated using the outer side (mucosal and the inner side (serosal of toad Pleurodema thaul skin. The results showed a decreased on electrophysiological parameters when it were administered concentrations of 33, 100 and 200 μM of Cr3+, the results also suggest that the administration of Cr3+ inhibits the ion transport in toad skin by the interaction of Cr3+ with lipid bilayers or protein constituents of membrane, and not by an inhibition of the active transport of ions across Na+ channels.

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

    DEFF Research Database (Denmark)

    Katz, U; Larsen, Erik Hviid

    1984-01-01

    The steady-state Cl- current across the skin of Bufo viridis adapted to tap water was found to be rectified. In skins bathed with NaCl Ringer on both sides, a large outward current, carried by influx of Cl-, was observed at a clamping voltage (V) of less than -50 mV (outside of the skin negative......, 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)...

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

    CERN Document Server

    House, Donald

    1989-01-01

    Depth Perception in Frogs and Toads provides a comprehensive exploration of the phenomenon of depth perception in frogs and toads, as seen from a neuro-computational point of view. Perhaps the most important feature of the book is the development and presentation of two neurally realizable depth perception algorithms that utilize both monocular and binocular depth cues in a cooperative fashion. One of these algorithms is specialized for computation of depth maps for navigation, and the other for the selection and localization of a single prey for prey catching. The book is also unique in that it thoroughly reviews the known neuroanatomical, neurophysiological and behavioral data, and then synthesizes, organizes and interprets that information to explain a complex sensory-motor task. The book will be of special interest to that segment of the neural computing community interested in understanding natural neurocomputational structures, particularly to those working in perception and sensory-motor coordination. ...

  11. Can epigenetics solve the case of the midwife toad?--a comment on Vargas.

    Science.gov (United States)

    Svardal, Hannes

    2010-12-15

    In a recent article in this journal, A. O. Vargas (2009. J Exp Zool B (Mol Dev Evol) 312:667-678) suggests to interpret the controversial midwife toad experiments of the early 20th century zoologist Paul Kammerer in the context of epigenetic inheritance. For information on Kammerer's work he resorts to a popular science book (Kammerer, '24. The Inheritance of Acquired Characteristics). However, the study of Kammerer's original publications reveals that there are substantial misunderstandings in Vargas' treatment of the subject. While Vargas' general idea-invoking epigenetic effects as an explanation of Kammerer's findings-remains attractive, at least two key aspects of his model need to be revised. Clarification of these issues is an important prerequisite for any experimental design with the aim to (dis)prove Kammerer and to establish a (potential) epigenetic basis of his observations about the mating behavior in midwife toads. © 2010 Wiley-Liss, Inc.

  12. Vasculature of the parotoid glands of four species of toads (bufonidae: bufo).

    Science.gov (United States)

    Hutchinson, Deborah A; Savitzky, Alan H

    2004-05-01

    The parotoid glands of toads (Bufonidae) consist of large aggregations of granular glands located between the otic region of the skull and the scapular region. To determine the circulatory pattern of these glands, we perfused the vascular systems of Bufo alvarius, B. marinus, B. terrestris, and B. valliceps with either India ink or Microfil, a fine latex. The perfused glands were studied by gross dissection, microscopic examination, and histology. The vascular patterns of the parotoid glands were compared to the arrangement of vessels in the dorsal skin of Rana sphenocephala (Ranidae), a frog that lacks parotoid glands. The parotoid glands of the four species of toads are supplied with blood by the lateral and dorsal cutaneous arteries and are drained by one or more branches of the internal jugular vein. The dorsal cutaneous artery supplies most of the blood to the parotoid glands in B. terrestris and B. valliceps. In B. alvarius and B. marinus, both the lateral and dorsal cutaneous arteries serve major roles in the blood supply of the glands. These patterns of blood flow have not been described previously for parotoid glands and conflict with earlier accounts for B. alvarius and B. marinus. The arteries and veins associated with the parotoid glands of toads are present in R. sphenocephala, but are arranged differently. In R. sphenocephala, the lateral cutaneous artery supplies the dorsal and lateral skin posterior to the shoulder region, whereas the dorsal cutaneous artery supplies the skin of the shoulder region. In toads, both the lateral and dorsal cutaneous arteries supply the skin of the shoulder region and ramify into subcutaneous capillaries that surround the secretory units of the parotoid glands. Extensive vasculature presumably is important for delivering cholesterol and other precursor molecules to the parotoid glands, where those compounds are converted into toxins. Copyright 2004 Wiley-Liss, Inc.

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

    Science.gov (United States)

    Chattopadhyay, Tanay

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

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

    Directory of Open Access Journals (Sweden)

    F. Meyer

    2001-09-01

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

  15. The things they carried: The pathogenic effects of old and new parasites following the intercontinental invasion of the Australian cane toad (Rhinella marina

    Directory of Open Access Journals (Sweden)

    D. Selechnik

    2017-12-01

    Full Text Available Brought to Australia in 1935 to control agricultural pests (from French Guiana, via Martinique, Barbados, Jamaica, Puerto Rico and Hawai'i, repeated stepwise translocations of small numbers of founders enabled the cane toad (Rhinella marina to escape many parasites and pathogens from its native range. However, the infective organisms that survived the journey continue to affect the dynamics of the toad in its new environment. In Australia, the native-range lungworm Rhabdias pseudosphaerocephala decreases its host's cardiac capacity, as well as growth and survival, but not rate of dispersal. The lungworm is most prevalent in long-colonised areas within the toads' Australian range, and absent from the invasion front. Several parasites and pathogens of Australian taxa have host-shifted to cane toads in Australia; for example, invasion-front toads are susceptible to spinal arthritis caused by the soil bacterium, Ochrobactrum anthropi. The pentastome Raillietiella frenata has host-shifted to toads and may thereby expand its Australian range due to the continued range expansion of the invasive toads. Spill-over and spill-back of parasites may be detrimental to other host species; however, toads may also reduce parasite loads in native taxa by acting as terminal hosts. We review the impact of the toad's parasites and pathogens on the invasive anuran's biology in Australia, as well as collateral effects of toad-borne parasites and pathogens on other host species in Australia. Both novel and co-evolved pathogens and parasites may have played significant roles in shaping the rapid evolution of immune system responses in cane toads within their invaded range. Keywords: Rhabdias pseudosphaerocephala, Ecoimmunology, Invasion, Enemy release hypothesis, Immune function, Bufo, Pathogen-mediated selection 1

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

    Science.gov (United States)

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

    2004-01-01

    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.

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

    Science.gov (United States)

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

    2010-01-01

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

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

    Science.gov (United States)

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

    2011-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    F. C. Coelho

    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.

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

    Directory of Open Access Journals (Sweden)

    Coelho F. C.

    2003-01-01

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

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

    Science.gov (United States)

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

    2003-02-01

    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.

  2. Population Genetic Structure and Species Status of Asiatic Toads (Bufo gargarizans) in Western China.

    Science.gov (United States)

    Wen, Guannan; Yang, Weizhao; Fu, Jinzhong

    2015-10-01

    We investigated the population genetic structure of Asiatic toads (Bufo gargarizans) from the mountains of western China to determine their species status, using genotypic data of ten microsatellite DNA loci and DNA sequences from one mitochondrial gene. A total of 197 samples from eight sites were examined, which cover a large range of elevations (559-3457 m), as well as all three traditionally defined species (or subspecies). AMOVA did not reveal any particularly large among-groups structure, whether the sites were grouped by drainage, elevation, region, or species (subspecies). Individual assignment tests placed all samples into two genetic clusters, which largely corresponded to their geographic locations. An isolation-by-distance pattern was also detected when an outlier population (site 3) was excluded. Furthermore, a mitochondrial gene tree revealed deep divergence among haplotypes, sometimes within the same site. The clade patterns were partially associated with geographic distribution but had no resemblance to the traditional 2- or 3-species classification. Overall, these toad populations harbor a large amount of genetic diversity and have very high population differentiation, but taken together the evidence suggests that all populations belong to a single species. Our results are consistent with most previous molecular studies, and we recommend using Bufo gargarizans to represent all Asiatic toad populations from western China without subspecies division.

  3. [Influence of the Concentration of Dissolved Oxygen on Embryonic Development of the Common Toad (Bufo bufo)].

    Science.gov (United States)

    Dmitrieva, E V

    2015-01-01

    Several series of experiments investigating the influence of dissolved oxygen concentrations on the growth rates and mortality in the embryogenesis of the common toad Bufo bufo were carried out. The experiments showed that, when the eggs develop singly, the lack of oxygen does not lead to an increase in mortality by the time of hatching and results only in a change in the dynamics of mortality: mortality occurs at an earlier stage of development than in the conditions of normal access to oxygen. Taking into account the combined effect of the density of eggs and the dissolved oxygen concentration, we increase the accuracy of analysis of the experimental results and improve the interpretation of the results. In the conditions of different initial density of eggs, the impact of the concentration of dissolved oxygen on mortality and rates of development of the common toad embryos is manifested in different ways. At high density, only a small percentage of embryos survives by the time of hatching, and the embryos are significantly behind in their development compared with the individuals that developed in normal oxygen conditions. The lack of oxygen dissolved in the water slows down the development of embryos of the common toad.

  4. Long-term observations of Boreal Toads at an ARMI apex site

    Science.gov (United States)

    Corn, Paul Stephen; Muths, Erin L.; Pilliod, David S.

    2011-01-01

    The U.S. Geological Survey’s Amphibian Research and Monitoring Initiative (ARMI) is a national project with goals to monitor the status and trends of amphibians, conduct research on causes of declines, and provide information and support to management agencies for conservation of amphibian populations. ARMI activities are organized around extensive inventories and place-based monitoring (such as collaboration with the Greater Yellowstone Inventory and Monitoring Network), and intensive population studies and research at selected locations (apex sites). One such site is an oxbow pond on the Buffalo Fork near the Black Rock Ranger Station east of Grand Teton National Park. We have been conducting mark-recapture of boreal toads (Anaxyrus boreas) at Black Rock since 2002. In concert with studies of other toad populations in the Rocky Mountains, we have documented a high rate of incidence of the chytrid fungus Batrachochytrium dendrobatidis (Bd) and a negative rate of growth of the toad population, but not the population crash or extinction observed in other populations with high prevalence of Bd. Long-term observations at other ARMI apex sites have proven invaluable for studying effects of climate change on amphibian behavior, and the Black Rock site has been upgraded with onsite recording of weather data and auditory monitoring of other amphibian species. Continued research at Black Rock will be critical for understanding the interrelated effects of climate and disease on amphibians in the Greater Yellowstone Ecosystem.

  5. Giant toads (Rhinella marina) living in agricultural areas have altered spermatogenesis.

    Science.gov (United States)

    McCoy, Krista A; Amato, Ciro M; Guillette, Louis J; St Mary, Colette M

    2017-12-31

    Across diverse taxa, germ cell development is controlled by an intricate cascade of processes that are tightly controlled by the hypothalamic-pituitary-gonadal axis. Endocrine disturbances, such as those induced by endocrine disrupting chemicals (EDCs) can negatively affect spermatogenesis. Here, we investigate whether spermatogenesis is altered in the giant toad, Rhinella marina, living in agricultural areas where EDCs are used relative to suburban areas. We also ask if reductions in spermatogenesis were associated with developmental gonadal abnormalities (intersex) found in the same frogs. We found that toads in agricultural areas exhibited reduced spermatogenesis relative to non-agricultural animals, and that those reductions were not associated with gross gonadal abnormalities. All toads living in agricultural areas had reduced spermatogenesis relative to those living in non-agricultural areas regardless of whether they had gonadal abnormalities originating during development. Similarities in reproductive dysfunction among diverse taxa living in agricultural areas, including humans, suggest that many vertebrate taxa living in agricultural areas around the globe are likely experiencing some level of reproductive dysfunction. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    Pizzatto, Lígia; Shine, Richard

    2011-08-01

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

  7. The effect of calcium withdrawal on the structure and function of the toad bladder.

    Science.gov (United States)

    Hays, R M; Singer, B; Malamed, S

    1965-06-01

    Previous reports have indicated that calcium is necessary to support active sodium transport by the toad bladder, and may be required as well in the action of vasopressin on both toad bladder and frog skin. The structure and function of the toad bladder has been studied in the absence of calcium, and a reinterpretation of the previous findings now appears possible. When calcium is withdrawn from the bathing medium, epithelial cells detach from one another and eventually from their supporting tissue. The short-circuit current (the conventional means of determining active sodium transport) falls to zero, and vasopressin fails to exert its usual effect on short-circuit current and water permeability. However, employing an indirect method for the estimation of sodium transport (oxygen consumption), it is possible to show that vasopressin exerts its usual effect on Q(oo2) when sodium is present in the bathing medium. Hence, it appears that the epithelial cells maintain active sodium transport when calcium is rigorously excluded from the bathing medium, and continue to respond to vasopressin. The failure of conventional techniques to show this can be attributed to the structural alterations in the epithelial layer in the absence of calcium. These findings may provide a model for the physiologic action of calcium in epithelia such as the renal tubule.

  8. Goal orientation by geometric and feature cues: spatial learning in the terrestrial toad Rhinella arenarum.

    Science.gov (United States)

    Sotelo, María Inés; Bingman, Verner Peter; Muzio, Rubén N

    2015-01-01

    Although of crucial importance in vertebrate evolution, amphibians are rarely considered in studies of comparative cognition. Using water as reward, we studied whether the terrestrial toad, Rhinella arenarum, is also capable of encoding geometric and feature information to navigate to a goal location. Experimental toads, partially dehydrated, were trained in either a white rectangular box (Geometry-only, Experiment 1) or in the same box with a removable colored panel (Geometry-Feature, Experiment 2) covering one wall. Four water containers were used, but only one (Geometry-Feature), or two in geometrically equivalent corners (Geometry-only), had water accessible to the trained animals. After learning to successfully locate the water reward, probe trials were carried out by changing the shape of the arena or the location of the feature cue. Probe tests revealed that, under the experimental conditions used, toads can use both geometry and feature to locate a goal location, but geometry is more potent as a navigational cue. The results generally agree with findings from other vertebrates and support the idea that at the behavioral-level geometric orientation is a conserved feature shared by all vertebrates.

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

    Science.gov (United States)

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

    2009-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Phalen David N

    2010-06-01

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

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

    Science.gov (United States)

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

    2010-06-10

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

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

    Science.gov (United States)

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

    2009-01-01

    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.

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

    Science.gov (United States)

    Wijethunga, Uditha; Greenlees, Matthew; Shine, Richard

    2016-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Elisa Cabrera-Guzmán

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

  15. Using experimental de-worming to measure the immunological and pathological impacts of lungworm infection in cane toads

    Directory of Open Access Journals (Sweden)

    Patrick B. Finnerty

    2017-12-01

    Full Text Available The immunological and pathological consequences of parasite infection can be more rigorously assessed from experimental manipulation than from correlational studies of natural infections. We used anthelmintic treatment to experimentally decrease intensities of lungworm infection in captive and free-ranging wild cane toads to assess parasite impacts on host immune responses. First, we administered the anthelmintic drug Ivermectin to both infected and uninfected toads, to distinguish drug effects per se from the impacts of killing lungworms. Worms began dying and decomposing <48 h after injection. The only immunological variables that were affected by anthelmintic treatment were bactericidal capacity of the blood which increased in parasitized toads (presumably triggered by decomposing worms in the lungs, and the phagocytic capacity of blood (which increased in both infected and uninfected toads; the latter effect presumably was caused by the injection of Ivermectin per se rather than removal of parasites. Second, we looked at correlates of variation in the infection intensity induced by de-worming (in both captive and free-ranging toads over an eight-week period. Heavier lungworm infection was associated with increased phagocytic ability of the host's blood, and a reduction in the host's liver mass (and hence, energy stores. Experimental de-worming thus revealed pathological and immunological costs of the presence of lungworms, and of their removal by anthelmintic injection. Keywords: Rhinella marina, Bufo marinus, Host, Parasite, Nematode

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

    Science.gov (United States)

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

    2014-11-22

    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. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

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

    Science.gov (United States)

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

    2014-01-01

    Understanding the behavior of species threatened with extinction is important for conservation planning and for solving problems facing species in captivity and the wild. We examined diurnal activity budgets and habitat use of the extinct in the wild Kihansi spray toad to provide insights into ongoing conservation initiatives for this species. Observations on eight target behaviors were made each morning and evening for 14 days, in two subpopulations at Kihansi and University of Dar es Salaam captive breeding centers. There were significantly more bouts of resting than calling, amplexing, hunting, walking, climbing, or feeding. There was no difference in mean time spent in each activity between the two subpopulations. The use of habitat was variable between age classes, subpopulations and sampling time. Young toads spent significantly more time resting at the top of vegetation and on walls while adults rested more on logs. Further, adults foraged more on the walls and vegetation in the morning and on the ground in the evening. Contrastingly, young toads foraged more on the ground in the morning and switched to elevated patches during evening. The similarity of the toads' behavior suggests that important biological traits are still maintained in captivity and retained across toad generations. Furthermore, temporal and spatial variations in the use of habitat structures between age groups suggest fine-scale resource partitioning to reduce competition in this gregarious species. These results highlight the importance of maintaining diverse habitat structures in captivity and are useful for planning species reintroduction and future restocking programs. © 2014 Wiley Periodicals, Inc.

  18. Acute thermal stressor increases glucocorticoid response but minimizes testosterone and locomotor performance in the cane toad (Rhinella marina.

    Directory of Open Access Journals (Sweden)

    Edward J Narayan

    Full Text Available Climatic warming is a global problem and acute thermal stressor in particular could be considered as a major stressor for wildlife. Cane toads (Rhinella marina have expanded their range into warmer regions of Australia and they provide a suitable model species to study the sub-lethal impacts of thermal stressor on the endocrine physiology of amphibians. Presently, there is no information to show that exposure to an acute thermal stressor could initiate a physiological stress (glucocorticoid response and secondly, the possible effects on reproductive hormones and performance. Answering these questions is important for understanding the impacts of extreme temperature on amphibians. In this study, we experimented on cane toads from Queensland, Australia by acclimating them to mildly warm temperature (25°C and then exposing to acute temperature treatments of 30°, 35° or 40°C (hypothetical acute thermal stressors. We measured acute changes in the stress hormone corticosterone and the reproductive hormone testosterone using standard capture and handling protocol and quantified the metabolites of both hormones non-invasively using urinary enzyme-immunoassays. Furthermore, we measured performance trait (i.e. righting response score in the control acclimated and the three treatment groups. Corticosterone stress responses increased in all toads during exposure to an acute thermal stressor. Furthermore, exposure to a thermal stressor also decreased testosterone levels in all toads. The duration of the righting response (seconds was longer for toads that were exposed to 40°C than to 30°, 35° or 25°C. The increased corticosterone stress response with increased intensity of the acute thermal stressor suggests that the toads perceived this treatment as a stressor. Furthermore, the results also highlight a potential trade-off with performance and reproductive hormones. Ultimately, exposure acute thermal stressors due to climatic variability could impact

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

    Science.gov (United States)

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

    2013-09-01

    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. © 2012 Blackwell Verlag GmbH.

  20. Assessment of Polycyclic Aromatic Hydrocarbon Contamination of Breeding Pools Utilized by the Puerto Rican Crested Toad, Peltophryne lemur.

    Science.gov (United States)

    Gjeltema, Jenessa; Stoskopf, Michael; Shea, Damian; De Voe, Ryan

    2012-01-01

    Habitat preservation and management may play an important role in the conservation of the Puerto Rican crested toad, Peltophryne lemur, due to this species' small geographic range and declining native wild population. Bioavailable water concentrations of Polycyclic Aromatic Hydrocarbon (PAH) contaminants within breeding pools at 3 sites were established using Passive Sampling Devices (PSDs) and gas chromatography-mass spectrometry (GC/MS). A more diverse population of PAH analytes were found in higher concentrations at the breeding site that allowed direct vehicular access, but calculated risk quotients indicated low risk to toad reproduction associated with the current PAH analyte levels.

  1. Ranking Landscape Development Scenarios Affecting Natterjack Toad (Bufo calamita) Population Dynamics in Central Poland

    Science.gov (United States)

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

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Gargaglioni L.H.

    1999-01-01

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

  3. Assessment of virally vectored autoimmunity as a biocontrol strategy for cane toads.

    Directory of Open Access Journals (Sweden)

    Jackie A Pallister

    Full Text Available BACKGROUND: The cane toad, Bufo (Chaunus marinus, is one of the most notorious vertebrate pests introduced into Australia over the last 200 years and, so far, efforts to identify a naturally occurring B. marinus-specific pathogen for use as a biological control agent have been unsuccessful. We explored an alternative approach that entailed genetically modifying a pathogen with broad host specificity so that it no longer caused disease, but carried a gene to disrupt the cane toad life cycle in a species specific manner. METHODOLOGY/PRINCIPAL FINDINGS: The adult beta globin gene was selected as the model gene for proof of concept of autoimmunity as a biocontrol method for cane toads. A previous report showed injection of bullfrog tadpoles with adult beta globin resulted in an alteration in the form of beta globin expressed in metamorphs as well as reduced survival. In B. marinus we established for the first time that the switch from tadpole to adult globin exists. The effect of injecting B. marinus tadpoles with purified recombinant adult globin protein was then assessed using behavioural (swim speed in tadpoles and jump length in metamorphs, developmental (time to metamorphosis, weight and length at various developmental stages, protein profile of adult globin and genetic (adult globin mRNA levels measures. However, we were unable to detect any differences between treated and control animals. Further, globin delivery using Bohle iridovirus, an Australian ranavirus isolate belonging to the Iridovirus family, did not reduce the survival of metamorphs or alter the form of beta globin expressed in metamorphs. CONCLUSIONS/SIGNIFICANCE: While we were able to show for the first time that the switch from tadpole to adult globin does occur in B. marinus, we were not able to induce autoimmunity and disrupt metamorphosis. The short development time of B. marinus tadpoles may preclude this approach.

  4. Assessment of virally vectored autoimmunity as a biocontrol strategy for cane toads.

    Science.gov (United States)

    Pallister, Jackie A; Halliday, Damien C T; Robinson, Anthony J; Venables, Daryl; Voysey, Rhonda D; Boyle, Donna G; Shanmuganathan, Thayalini; Hardy, Christopher M; Siddon, Nicole A; Hyatt, Alex D

    2011-01-25

    The cane toad, Bufo (Chaunus) marinus, is one of the most notorious vertebrate pests introduced into Australia over the last 200 years and, so far, efforts to identify a naturally occurring B. marinus-specific pathogen for use as a biological control agent have been unsuccessful. We explored an alternative approach that entailed genetically modifying a pathogen with broad host specificity so that it no longer caused disease, but carried a gene to disrupt the cane toad life cycle in a species specific manner. The adult beta globin gene was selected as the model gene for proof of concept of autoimmunity as a biocontrol method for cane toads. A previous report showed injection of bullfrog tadpoles with adult beta globin resulted in an alteration in the form of beta globin expressed in metamorphs as well as reduced survival. In B. marinus we established for the first time that the switch from tadpole to adult globin exists. The effect of injecting B. marinus tadpoles with purified recombinant adult globin protein was then assessed using behavioural (swim speed in tadpoles and jump length in metamorphs), developmental (time to metamorphosis, weight and length at various developmental stages, protein profile of adult globin) and genetic (adult globin mRNA levels) measures. However, we were unable to detect any differences between treated and control animals. Further, globin delivery using Bohle iridovirus, an Australian ranavirus isolate belonging to the Iridovirus family, did not reduce the survival of metamorphs or alter the form of beta globin expressed in metamorphs. While we were able to show for the first time that the switch from tadpole to adult globin does occur in B. marinus, we were not able to induce autoimmunity and disrupt metamorphosis. The short development time of B. marinus tadpoles may preclude this approach.

  5. Antiproliferative activity and chemical composition of the venom from the Amazonian toad Rhinella marina (Anura: Bufonidae).

    Science.gov (United States)

    Schmeda-Hirschmann, Guillermo; Quispe, Cristina; Arana, Gabriel Vargas; Theoduloz, Cristina; Urra, Félix A; Cárdenas, César

    2016-10-01

    Little is known on the composition of Peruvian Amazon toad venoms. The large toad Rhinella marina is common in the cleared tropical forests of the Iquitos region and is regarded as poisonous. The venom from two different populations of R. marina was collected in the Departamento de Loreto, Perú. The samples were assessed for antiproliferative effect and composition. Some 29 compounds were identified or tentatively identified from the venom by spectroscopic and spectrometric means. The main free bufadienolide was marinobufagin 7 while marinobufotoxin 15 and bufalitoxin 9 were the main bufadienolide argininyl diacid derivatives. The alkaloids dehydrobufotenin 28 and bufotenidin 29 were present in both venoms. The main difference in the venoms was the relative ratio of argininyl diacids from bufadienolides to free bufadienolides. The argininyl diacids included derivatives from bufalin, marinobufagin, telocinobufagin, hellebrigenin, resibufogenin and bufotalinin. Four compounds, including undecadienoyl aginine 6 and three argininyl diacids from bufadienolides were tentatively identified for the first time in the samples. The venom showed a strong antiproliferative effect towards MRC-5 normal human lung fibroblasts (0.063-0.247 μg/mL), AGS human gastric adenocarcinoma cells (0.076-0.272 μg/mL), SK-MES-1 human lung cancer cells (0.154-0.296 μg/mL), J82 human bladder carcinoma cells (0.169-0.212 μg/mL), and HL-60 human promyelocytic leukemia (0.071-0.283 μg/mL). The antiproliferative effect is mediated by ROS production and cell cycle arrest in human breast cancer cells (MCF7 and MDA-MB-231). This is the first report on the composition of R. marina venom from the Peruvian Amazon pointing out the need to include different venom samples to get a better picture from the activity and composition of South American toad defense substances. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Kamila W Franz

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

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

    Science.gov (United States)

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

    2011-01-01

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

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

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Kristensen, P

    1978-01-01

    Two types of chloride current response to a step-wise hyperpolarization of the toad skin is demonstrated: (1) An "instantaneous" response observed immediately upon voltage change, and (2) a subsequent slow response, the time course of which is sigmoidal. The slow response is due to an increase......-state phenomenon: In skins hyperpolarized for a few minutes, the "instantaneous" I-V curves show that the chloride pathway in the conducting state allows a large inward chloride current (outward chloride flux) to pass in the voltage range 40 mV greater than V greater than 0 mV. Calculations based on a three...

  9. Melanophryniscus montevidensis (Philippi, 1902 (Anura: Bufonidae

    Directory of Open Access Journals (Sweden)

    Tedros, Marcelo

    2001-01-01

    Full Text Available Brasil, Estado de Rio Grande do Sul, Alvorada, Barra do Chui, 33°45'S 53°16' W. Febrero de 1989. Colector: M. Tedros. (Colección de Batracios de la Secci ón Zoología Vertebrados de la Facultad de Ciencias de la Universidad de la República, Uruguay ZVCB 7276, ZVCB 7277 y ZVCB 7278.

  10. 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...

  11. Post-breeding habitat use by adult boreal toads (Bufo boreas boreas) after wildfire in Glacier National Park, USA

    Science.gov (United States)

    C. Gregory Guscio; Blake R. Hossack; Lisa A. Eby; Paul Stephen Corn

    2008-01-01

    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...

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

    Science.gov (United States)

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

    2008-01-01

    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.

  13. METAPOPULATION PROCESSES OR INFINITE DISPERSAL?: HABITAT PATCH OCCUPANCY BY 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 P...

  14. METAPOPULATION PROCESSES OF INFINITE DISPERSAL?: HABITAT PATCH OCCUPANCY BY TOADS (BUFO PUNCTATUS) IN A NATURALLY FRAGMENTED DESERT

    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 P...

  15. METAPOPULATION PROCESSES OF INFINITE DISPERSAL: HABITAT PATCH OCCUPANCY BY 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 P...

  16. METAPOPULATION PROCESSES OR INFINITE DISPERSAL?: HABITAT PATCH OCCUPANCY BY TOADS (BUFO PUNCTATUS) IN A NAUTRALLY 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 P...

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

    Science.gov (United States)

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

    2004-01-01

    In the southeastern United States, coarse woody debris (CWD) typically harbors high densities of invertebrates. However, its importance as a foraging substrate for southeastern amphibians is relatively unknown. We examined effects of CWD manipulations on diet composition of southern toads (Bufo tmrestns) in upland loblolly pine (Pinus taeda) stands...

  18. Excitatory and depressant effects of dieldrin and aldrin-transdiol in the spinal cord of the toad (Xenopus laevis)

    NARCIS (Netherlands)

    Akkermans, L.M.A.; Bercken, J. van den; Versluijs-Helder, M.

    1975-01-01

    An investigation was made into the action of the insecticide dieldrin and one of its metabolites, aldrin-transdiol, on the isolated spinal cord of the toad, Xenopus laevis. Conventional electrophysiological techniques were used for stimulating and recording of dorsal and ventral spinal roots. An

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

    Directory of Open Access Journals (Sweden)

    Santos, X.

    2007-06-01

    Full Text Available 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 factors: toad abundance, traffic density and quality of water bodies for breeding. On the road with the highest incidence of road kills we investigated whether deaths occurred at specific spots or in a random manner. The road was divided into 500 m sections and each section was classified according to biotic (type of vegetation and abiotic (presence of streams, roadside topography variables. Multiple correspondence analysis showed that sections with streams crossing under the road had the highest mortality rate, suggesting that such water bodies flowing into the breeding pond are the toads’ main migratory pathways for hibernation and breeding. As toads use the same migratory routes each year, it is critical to identify areas with a high potential mortality so that efficient measures can be designed to increase wildlife permeability, and thereby reduce habitat fragmentation. This methodology could be applied in other areas with high amphibian mortality.

  20. 77 FR 6815 - Emergency Exemption; Issuance of Emergency Permit To Salvage Houston Toads Affected by a Wildfire...

    Science.gov (United States)

    2012-02-09

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Fish and Wildlife Service Emergency Exemption; Issuance of Emergency Permit To Salvage Houston Toads Affected by a Wildfire in Bastrop County, TX AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of...

  1. Characterization and quantification of corticosteroid-binding globulin in a southern toad, Bufo terrestris, exposed to coal-combustion-waste

    Energy Technology Data Exchange (ETDEWEB)

    Ward, C.K.; Fontes, C.; Breuner, C.W.; Mendonca, M.T. [Auburn University, Auburn, AL (USA). Dept. of Biological Science

    2007-05-15

    Corticosteroid-binding globulin (CBG) is a plasma protein that binds corticosterone and may regulate access of hormone to tissues. The role of CBG during a stress response is not clear. In this study, southern toads, Bufo terrestris, were exposed to a chronic pollutant (coal-combustion-waste), to determine changes in CBG and free corticosterone levels. Since toads exposed to chronic pollutants in previous studies did not exhibit the predicted changes in metabolic rate and mass, but did experience a significant elevation in total corticosterone, we hypothesized that CBG would likewise increase and thus, mitigate the effects of a chronic (i.e. 2 months) pollutant stressor. To conduct this study, we first characterized the properties of CBG in southern toads. After characterization, we monitored the changes in CBG, total corticosterone, and free corticosterone in male toads that were exposed to either coal-combustion-waste or control conditions. CBG increased in all groups throughout the experiment. Total corticosterone, on the other hand, was only significantly elevated at four weeks of exposure to coal-combustion-waste. The increase in CBG did not parallel the increase in total corticosterone; as a result, free corticosterone levels were not buffered by CBG, but showed a peak at four weeks similar to total corticosterone. This finding indicates that, in this species, CBG may not provide a protective mechanism during long-term pollution exposure.

  2. The status and relationships of some East African Earless Toads (Anura, Bufonidae) with a description of a new species

    NARCIS (Netherlands)

    Grandison, A.G.C.

    1972-01-01

    INTRODUCTION In comparing some small Ethiopian Bufo with the descriptions, types and other examples of numerous forms from East and Central African countries I became very much aware of the confusion that exists in the taxonomy and of the need for a revision of this group of dwarf toads. Most of the

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-04-01

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

  4. Biomarker analysis of American toad (Anaxyrus americanus) and grey tree frog (Hyla versicolor) tadpoles following exposure to atrazine.

    Science.gov (United States)

    The objective of the current study was to use a biomarker-based approach to investigate the influence of atrazine exposure on American toad (Anaxyrus americanus) and grey tree frog (Hyla versicolor) tadpoles. Atrazine is one of the most frequently detected herbicides in environme...

  5. Movements and habitat use of Yosemite toads (Anaxyrus (formerly Bufo) canorus) in the Sierra National Forest, California

    Science.gov (United States)

    Christina T. Liang

    2013-01-01

    The Yosemite Toad (Anaxyrus (Bufo) canorus) is a high-elevation species endemic to the central Sierra Nevada mountain range in California whose populations are in decline. There is limited information on their terrestrial movement and habitat use, which impairs our understanding of the ecology and habitat...

  6. Wildfire effects on water temperature and selection of breeding sites by the boreal toad (Bufo boreas) in seasonal wetlands

    Science.gov (United States)

    Blake R. Hossack; Paul Stephen Corn

    2008-01-01

    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...

  7. Toxin-resistant isoforms of Na+/K+-ATPase in snakes do not closely track dietary specialization on toads

    Science.gov (United States)

    Gonzalez, Jonathan; Takeuchi, Hirohiko; Mori, Akira

    2016-01-01

    Toads are chemically defended by bufadienolides, a class of cardiotonic steroids that exert toxic effects by binding to and disabling the Na+/K+-ATPases of cell membranes. Some predators, including a number of snakes, have evolved resistance to the toxic effects of bufadienolides and prey regularly on toads. Resistance in snakes to the acute effects of these toxins is conferred by at least two amino acid substitutions in the cardiotonic steroid binding pocket of the Na+/K+-ATPase. We surveyed 100 species of snakes from a broad phylogenetic range for the presence or absence of resistance-conferring mutations. We found that such mutations occur in a much wider range of taxa than previously believed. Although all sequenced species known to consume toads exhibited the resistance mutations, many of the species possessing the mutations do not feed on toads, much less specialize on that food source. This suggests that either there is little performance cost associated with these mutations or they provide an unknown benefit. Furthermore, the distribution of the mutation among major clades of advanced snakes suggests that the origin of the mutation reflects evolutionary retention more than dietary constraint. PMID:27852804

  8. Differences and Similarities among Parotoid Macrogland Secretions in South American Toads: A Preliminary Biochemical Delineation

    Directory of Open Access Journals (Sweden)

    Juliana Mozer Sciani

    2013-01-01

    Full Text Available Amphibians are known by cutaneous glands, spread over the skin, containing toxins (proteins, peptides, biogenic amines, steroidal bufadienolides, and alkaloids used as chemical defense against predators and microbial infection. Toads are characterized by the presence of parotoid macroglands. The common toads have lately been divided into two genera: Bufo (Europe, Asia, and Africa and Rhinella (South America. Basal Rhaebo genus is exclusively of Central America and Amazon region. Although Rhinella and Rhaebo are related, species may share differences due to the diversity of environments that they live in. In this work, we have performed a biochemical characterization of the components of the poison of eight Rhinella species and one Rhaebo by means of RP-HPLC with either UV or MS detection and by SDS-PAGE, in order to verify whether phylogenetic and biological differences, such as habitat, diet, and defensive strategies, between them may also be reflected in poison composition. Although some components were common among the secretions, we were able to identify exclusive molecules to some species. The fact that closely related animals living in different habitats secrete different molecules into the skin is an indication that biological features, and not only evolution, seem to directly influence the skin secretion composition.

  9. Ba2+-inhibitable /sup 86/Rb+ fluxes across membranes of vesicles from toad urinary bladder

    Energy Technology Data Exchange (ETDEWEB)

    Garty, H.; Civan, M.M.

    1987-01-01

    /sup 86/Rb+ fluxes have been measured in suspensions of vesicles prepared from the epithelium of toad urinary bladder. A readily measurable barium-sensitive, ouabain-insensitive component has been identified; the concentration of external Ba2+ required for half-maximal inhibition was 0.6 mM. The effects of externally added cations on /sup 86/Rb+ influx and efflux have established that this pathway is conductive, with a selectivity for K+, Rb+ and Cs+ over Na+ and Li+. The Rb+ uptake is inversely dependent on external pH, but not significantly affected by internal Ca2+ or external amiloride, quinine, quinidine or lidocaine. It is likely, albeit not yet certain, that the conductive Rb+ pathway is incorporated in basolateral vesicles oriented right-side-out. It is also not yet clear whether this pathway comprises the principle basolateral K+ channel in vivo, and that its properties have been unchanged during the preparative procedures. Subject to these caveats, the data suggest that the inhibition by quinidine of Na+ transport across toad bladder does not arise primarily from membrane depolarization produced by a direct blockage of the basolateral channels. It now seems more likely that the quinidine-induced elevation of intracellular Ca2+ activity directly blocks apical Na+ entry.

  10. Invasive cane toads are unique in shape but overlap in ecological niche compared to Australian native frogs.

    Science.gov (United States)

    Vidal-García, Marta; Keogh, J Scott

    2017-10-01

    Invasive species are an important issue worldwide but predicting invasiveness, and the underlying mechanisms that cause it, is difficult. There are several primary hypotheses to explain invasion success. Two main hypothesis based on niche spaces stand out as alternative, although not exclusive. The empty niche hypothesis states that invaders occupy a vacant niche space in the recipient community, and the niche competition hypothesis states that invaders overlap with native species in niche space. Studies on trait similarity/dissimilarity between the invader and native species can provide information on their niche overlap. Here, we use the highly invasive and well-studied cane toad (Rhinella marina) to test these two hypotheses in Australia, and assess its degree of overlap with native species in several niche dimensions. We compare extensive morphological and environmental data of this successful invader to 235 species (97%) of native Australian frogs. Our study is the first to document the significant morphological differences between the invasive cane toad and a continent-wide frog radiation: despite significant environmental overlap, cane toads were distinct in body size and shape from most Australian frog species, suggesting that in addition to their previously documented phenotypic plasticity and wide environmental and trophic niche breadth, their unique shape also may have contributed to their success as an invasive species in Australia. Thus, the invasive success of cane toads in Australia may be explained through them successfully colonizing an empty niche among Australian anurans. Our results support that the cane toad's distinct morphology may have played a unique role in the invasiveness of this species in Australia, which coupled with a broad environmental niche breadth, would have boosted their ability to expand their distribution across Australia. We also propose RLLR (Relative limb length ratio) as a potentially useful measure of identifying

  11. Wild Cane Toads (Rhinella marina) Expel Foreign Matter from the Coelom via the Urinary Bladder in Response to Internal Injury, Endoparasites and Disease: e0134036

    National Research Council Canada - National Science Library

    Crystal Kelehear; Hugh I Jones; Benjamin A Wood; Richard Shine

    2015-01-01

      Dissections of >1,200 wild-caught cane toads (Rhinella marina) in tropical Australia confirm a laboratory report that anurans can expel foreign objects from the coelom by incorporating them into the urinary bladder...

  12. Wild cane toads (Rhinella marina) expel foreign matter from the coelom via the urinary bladder in response to internal injury, endoparasites and disease

    National Research Council Canada - National Science Library

    Kelehear, Crystal; Jones, Hugh I; Wood, Benjamin A; Shine, Richard

    2015-01-01

    Dissections of >1,200 wild-caught cane toads (Rhinella marina) in tropical Australia confirm a laboratory report that anurans can expel foreign objects from the coelom by incorporating them into the urinary bladder...

  13. CRED Optical Validation Data at the island of Ta'u in American Samoa, 2004 to Support Benthic Habitat Mapping (TOAD)

    Data.gov (United States)

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

  14. CRED Optical Validation Data at the island of Ta'u in American Samoa, 2012 to support Benthic Habitat Mapping (TOAD)

    Data.gov (United States)

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

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

    Directory of Open Access Journals (Sweden)

    Ashlie Hartigan

    Full Text Available 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.

  16. Community structure of helminth parasites of the "Cururu" toad, Rhinella icterica (Anura: Bufonidae) from southern Brazil.

    Science.gov (United States)

    Dos Santos, Viviane Gularte Tavares; Amato, Suzana B; Borges-Martins, Márcio

    2013-03-01

    Sixty specimens of the "cururu" toad, Rhinella icterica (Spix 1824) (Bufonidae), were collected in Campo Belo do Sul, State of Santa Catarina, Brazil, between May 2009 and January 2011, and were examined for the presence of helminth parasites. Nine species of adult helminths were found: Catadiscus cohni, Rudolphitrema rudolphii, Cylindrotaenia sp., Rhabdias fuelleborni, Strongyloides sp., Cosmocerca rara, Cosmocerca brasiliensis, Aplectana elenae, and Oxyascaris sp., in addition to an unidentified adult nematode species. Females of cosmocercid nematodes, proteocephalan plerocercoid, and acanthocephalan cystacanth were found but not identified for lack absolute of taxonomic characters. The sex of the anurans had no influence on prevalence, abundance, and richness of helminth species. Length and body mass of hosts did not influence the prevalence and richness of helminths, while the abundance of R. fuelleborni was significantly correlated with both parameters.

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

    Directory of Open Access Journals (Sweden)

    Miao Liu

    2015-04-01

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

  18. Rapid differentiation of sexual signals in invasive toads: call variation among populations

    Science.gov (United States)

    Yasumiba, Kiyomi; Duffy, Richard L.; Parsons, Scott A.; Alford, Ross A.; Schwarzkopf, Lin

    2016-01-01

    Advertisement calls tend to differ among populations, based on morphological and environmental factors, or simply geographic distance, in many taxa. Invasive cane toads (Rhinella marina) were introduced to Australia in 1935 and their distribution has expanded at increasing rates over time. Rapid evolution occurred in morphological and behavioural characters that accelerate dispersal, but the effects of rapid expansion on sexual signals have not been examined. We collected advertisement calls from four populations of different ages since invasion, and analysed the geographic differentiation of seven call parameters. Our comparisons indicate that the calls of R. marina differ among Australian populations. The signal variation was not simply clinal with respect to population age, climate, or morphological differentiation. We suggest that selection on signalling among populations has been idiosyncratic and may reflect local female preferences or adaptation to environmental factors that are not clinal such as energy availability. PMID:27328666

  19. Phenotypic divergence of the common toad (Bufo bufo) along an altitudinal gradient: evidence for local adaptation.

    Science.gov (United States)

    Luquet, E; Léna, J-P; Miaud, C; Plénet, S

    2015-01-01

    Variation in the environment can induce different patterns of genetic and phenotypic differentiation among populations. Both neutral processes and selection can influence phenotypic differentiation. Altitudinal phenotypic variation is of particular interest in disentangling the interplay between neutral processes and selection in the dynamics of local adaptation processes but remains little explored. We conducted a common garden experiment to study the phenotypic divergence in larval life-history traits among nine populations of the common toad (Bufo bufo) along an altitudinal gradient in France. We further used correlation among population pairwise estimates of quantitative trait (QST) and neutral genetic divergence (FST from neutral microsatellite markers), as well as altitudinal difference, to estimate the relative role of divergent selection and neutral genetic processes in phenotypic divergence. We provided evidence for a neutral genetic differentiation resulting from both isolation by distance and difference in altitude. We found evidence for phenotypic divergence along the altitudinal gradient (faster development, lower growth rate and smaller metamorphic size). The correlation between pairwise QSTs-FSTs and altitude differences suggested that this phenotypic differentiation was most likely driven by altitude-mediated selection rather than by neutral genetic processes. Moreover, we found different divergence patterns for larval traits, suggesting that different selective agents may act on these traits and/or selection on one trait may constrain the evolution on another through genetic correlation. Our study highlighted the need to design more integrative studies on the common toad to unravel the underlying processes of phenotypic divergence and its selective agents in the context of environmental clines.

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Karolina Stark

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

  2. Modulation effects of cordycepin on the skeletal muscle contraction of toad gastrocnemius muscle.

    Science.gov (United States)

    Yao, Li-Hua; Meng, Wei; Song, Rong-Feng; Xiong, Qiu-Ping; Sun, Wei; Luo, Zhi-Qiang; Yan, Wen-Wen; Li, Yu-Ping; Li, Xin-Ping; Li, Hai-Hang; Xiao, Peng

    2014-03-05

    Isolated toad gastrocnemius muscle is a typical skeletal muscle tissue that is frequently used to study the motor system because it is an important component of the motor system. This study investigates the effects of cordycepin on the skeletal muscle contractile function of isolated toad gastrocnemius muscles by electrical field stimulation. Results showed that cordycepin (20 mg/l to 100 mg/l) significantly decreased the contractile responses in a concentration-dependent manner. Cordycepin (50 mg/l) also produced a rightward shift of the contractile amplitude-stimulation intensity relationship, as indicated by the increases in the threshold stimulation intensity and the saturation stimulation intensity. However, the most notable result was that the maximum amplitude of the muscle contractile force was significantly increased under cordycepin application (122±3.4% of control). This result suggests that the skeletal muscle contractile function and muscle physical fitness to the external stimulation were improved by the decreased response sensitivity in the presence of cordycepin. Moreover, cordycepin also prevented the repetitive stimulation-induced decrease in muscle contractile force and increased the recovery amplitude and recovery ratio of muscle contraction. However, these anti-fatigue effects of cordycepin on muscle contraction during long-lasting muscle activity were absent in Ca2+-free medium or in the presence of all Ca2+ channels blocker (0.4 mM CdCl2). These results suggest that cordycepin can positively affect muscle performance and provide ergogenic and prophylactic benefits in decreasing skeletal muscle fatigue. The mechanisms involving excitation-coupled Ca2+ influxes are strongly recommended.

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

    Directory of Open Access Journals (Sweden)

    F. C. Coelho

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

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

    Directory of Open Access Journals (Sweden)

    Coelho F. C.

    2003-01-01

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

  5. Miniaturized Bioaffinity Assessment Coupled to Mass Spectrometry for Guided Purification of Bioactives from Toad and Cone Snail

    Directory of Open Access Journals (Sweden)

    Ferry Heus

    2014-02-01

    Full Text Available 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 (<90 min, 500 ng venom injected, ligands are detected and identified. To show applicability for non-peptides, small molecular ligands such as steroidal ligands were identified in skin secretions from two toad species (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 α7-nAChR confirmed the identity and bioactivity of several new ligands.

  6. Indolealkylamines from Toad Vertebrates and Sea Invertebrates - Their Identification and Potential Activities on the Central Nervous System.

    Science.gov (United States)

    Zulfiker, Abu Hasanat Md; Mariottini, Gian Luigi; Qi, Ji; Grice, I Darren; Wei, Ming Q

    2016-01-01

    Indolealkylamines (IAAs) are biogenic amines and derivatives of 5-hydroxytryptamine, acting primarily on serotonin receptors. IAAs are often considered the most thoroughly investigated group of aromatic amines in the amphibian skin. On the contrary, at present the detailed knowledge of these compounds in lower organisms is still limited and the biogenic amine receptors, mediating hormonal and modulatory functions, are largely unknown in primitive invertebrates. However, some active research is currently underway investigating this class of biogenic amines. Notably, during the last three decades several investigations have demonstrated the biological activity of endogenous biogenic amines in cnidarians, which are known to be the lowest beings equipped with an effective, even though rudimentary, nervous system. Toads, especially those from the Bufonidae family, constitute a significant part of the amphibian family and are an identified source of IAAs. To date fourteen IAAs have been identified in the skins of toad species. All are 5-substituted IAA derivatives acting mainly on the central nervous system (CNS), with most exhibiting some degrees of 5-HT2A receptor selectivity. This selective ability presents potential for their use in the development of treatments for various disorders such as schizophrenia, depression, anxiety, obsessive-compulsive disorders and chronic pain conditions. There are indications that some IAAs may also show subclass selectivity through binding to multiple 5-HT receptor subtypes. Thus, there exists an additional promising platform for the development of therapeutics targeting multiple 5-HT receptors. In this review, IAAs occurring naturally in various species of toad skins, which have been identified and isolated since 1944 are summarized and comparisons are made with similar biogenic amines recognized in cnidarians to date. Such comparisons highlight the potential to utilize existing knowledge gathered from vertebrates, such as toads in

  7. Assessment of Polycyclic Aromatic Hydrocarbon Contamination of Breeding Pools Utilized by the Puerto Rican Crested Toad, Peltophryne lemur

    OpenAIRE

    Jenessa Gjeltema; Michael Stoskopf; Damian Shea; Ryan De Voe

    2012-01-01

    Habitat preservation and management may play an important role in the conservation of the Puerto Rican crested toad, Peltophryne lemur, due to this species’ small geographic range and declining native wild population. Bioavailable water concentrations of Polycyclic Aromatic Hydrocarbon (PAH) contaminants within breeding pools at 3 sites were established using Passive Sampling Devices (PSDs) and gas chromatography-mass spectrometry (GC/MS). A more diverse population of PAH analytes were found ...

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

    DEFF Research Database (Denmark)

    Allentoft, Morten E.; Siegismund, Hans Redlef; Briggs, Lars

    2009-01-01

    The European natterjack toad (Bufo calamita) has declined rapidly in recent years, primarily due to loss of habitat, and in Denmark it is estimated that 50% of the isolated populations are lost each decade. To efficiently manage and conserve this species and its genetic diversity, knowledge...... in a highly fragmented gene pool. Future conservation management of this species is discussed in light of these results....

  9. Frogs in the spotlight: a 16-year survey of native frogs and invasive toads on a floodplain in tropical Australia.

    Science.gov (United States)

    Brown, Gregory P; Shine, Richard

    2016-07-01

    Although widespread declines in anuran populations have attracted considerable concern, the stochastic demographics of these animals make it difficult to detect consistent trends against a background of spatial and temporal variation. To identify long-term trends, we need datasets gathered over long time periods, especially from tropical areas where anuran biodiversity is highest. We conducted road surveys of four anurans in the Australian wet-dry tropics on 4637 nights over a 16-year period. Our surveys spanned the arrival of invasive cane toads (Rhinella marina), allowing us to assess the invader's impact on native anuran populations. Our counts demonstrate abrupt and asynchronous shifts in abundance and species composition from one year to the next, not clearly linked to rainfall patterns. Typically, periods of decline in numbers of a species were limited to 1-2 years and were followed by 1- to 2-year periods of increase. No taxa showed consistent declines over time, although trajectories for some species showed significant perturbations coincident with the arrival of toads. None of the four focal frog species was less common at the end of the study than at the beginning, and three of the species reached peak abundances after toad arrival. Survey counts of cane toads increased rapidly during the initial stage of invasion but have subsequently declined and fluctuated. Distinguishing consistent declines versus stochastic fluctuations in anuran populations requires extensive time-series analysis, coupled with an understanding of the shifts expected under local climatic conditions. This is especially pertinent when assessing impacts of specific perturbations such as invasive species.

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

    Directory of Open Access Journals (Sweden)

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

    2011-12-01

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

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

    Science.gov (United States)

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

    2006-01-01

    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

  12. Phylogenetic relationships and call structure in four African bufonid ...

    African Journals Online (AJOL)

    1993-02-18

    Feb 18, 1993 ... data to reconstruct a phylogeny of Old World newl, in the genus Triturus. They inferrC

  13. On the distribution of Bidder's organ in Bufonids

    NARCIS (Netherlands)

    Dubois, R.

    1947-01-01

    It is a well-known fact that Bidder's organ is an undeveloped ovary. It is found in all adult male and in many adult female as well as in all juvenile male and female specimens of Bufo-species, and it is situated between the fatbody and the gonad. The fact that Bidder's organ is a potential ovary is

  14. Department oJZoology. University oJTexas bufonids Schismaderma ...

    African Journals Online (AJOL)

    University of Texas Library of Anuran Sounds;. A. G. C. Grandison, British Museum (Natural History). We are grateful to the following for providing preserved or I iving material: J.-L. Amiet; American Museum of Natural History; Academy of Natural Sciences, Philadelphia;. Umtali Museum; Museo Civico di Storia Naturale, ...

  15. Department oJZoology. University oJTexas bufonids Schismaderma ...

    African Journals Online (AJOL)

    Perhaps the acoustical similarity is a result of convergence. The. Type I call is known in only four species of Bufo that occur outside Mrica - B. hufo and B. calamita of Eurasia, and B. crucifer and B. blombergi of South America. The South American leptodactylid species Odontophrynus americanus also has this call type.

  16. 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.

    Science.gov (United States)

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

    2014-01-01

    The chytrid fungus Batrachochytrium dendrobatidis is a significant cause of the worldwide decline in amphibian populations; however, various amphibian species are capable of coexisting with B. dendrobatidis. Among them are boreal toads (Anaxyrus (Bufo) boreas boreas) located in Grand Teton National Park (GTNP) in Wyoming, USA. The purpose of this study was to identify cultivable bacterial isolates from the skin microbiota of boreal toads from GTNP and determine if they were capable of inhibiting B. dendrobatidis in vitro, and therefore might be a factor in the toad's coexistence with this pathogen. Isolates from 6 of 21 genera tested were found to inhibit the growth of B. dendrobatidis. These bacteria represent diverse lineages such as the Gammaproteobacteria, the Betaproteobacteria, and the Bacteroidetes/Chlorobium groups. We propose that these bacteria compete via microbial antagonism with B. dendrobatidis.

  17. Proliferative events and apoptotic remodelling in retinal development of common toad (Bufo bufo).

    Science.gov (United States)

    Pinelli, Claudia; Sansone, Alfredo; De Maio, Anna; Morgillo, Antonietta; Scandurra, Anna; D'Aniello, Biagio

    2016-01-01

    Proliferation and apoptosis are fundamental processes in the development of the retina, and a proper balance of the two phenomena is crucial to correct development of the organ. Despite intense investigation in different vertebrates, only a few studies have analyzed the cell death and the cell division quantitatively in the same species during development. Here we studied the time course of apoptosis and proliferation in the retina of common toad, Bufo bufo, and discuss the findings in an evolutionary perspective. We found cells that were dividing first scattered throughout the retina, then, in later stages, proliferation was confined to the ciliary marginal zone. This pattern was confirmed by the expression of the proliferative marker PCNA. Both proliferation and apoptosis occurred in successive waves, and two apoptotic peaks were detected: one at premetamorphosis 1 and the second at prometamorphosis. PARP-1, a known molecular marker of apoptosis, was used to confirm the data obtained by counting pyknotic nuclei. In summary, proliferative and apoptotic waves display an inverse time-relationship through development, with apoptotic peaks coinciding with low proliferation phases. In a comparative perspective, amphibians follow a developmental pattern similar to other vertebrates, although with different timing. © 2015 Wiley Periodicals, Inc.

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

    Science.gov (United States)

    Oromi, N; Richter-Boix, A; Sanuy, D; Fibla, J

    2012-01-01

    Across altitudinal and latitudinal gradients, the proportion of suitable habitats varies, influencing the individual dispersal that ultimately can produce differentiation among populations. The natterjack toad (Bufo calamita) is distributed across a wide geographic range that qualifies the species as interesting for a geographic analysis of its genetic variability. Five populations of B. calamita in the Sierra de Gredos (Spain) were studied in an altitudinal gradient ranging from 750 to 2270 m using microsatellite markers. In addition, we analyzed the latitudinal genetic variation in B. calamita within a global European distribution using genetic diversity parameters (mean number of alleles per locus [Ma] and expected heterozygosity [HE]) obtained from our results and those published in the literature. The low level of genetic differentiation found between populations of B. calamita (Fst ranging from 0.0115 to 0.1018) and the decreases in genetic diversity with altitude (Ma from 13.6 to 8.3, HE from 0.82 to 0.74) can be interpreted by the combined effects of discontinuous habitat, produced mainly by the high slopes barriers and geographic distance. In the latitudinal gradient, genetic diversity decreases from south to north as a consequence of the colonization of the species from the Pleistocene refugium. We conclude that the genetic variability in B. calamita along its wide altitudinal and latitudinal geographic distribution mainly reflects the colonization history of the species after the last glacial period. PMID:22957202

  19. Ultrastructural and Molecular Changes in the Developing Small Intestine of the Toad Bufo regularis

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

    Ibrahim, Mohamed Moussa Ibrahim

    2008-10-16

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

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

    Directory of Open Access Journals (Sweden)

    Ulisses Caramaschi

    2012-08-01

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

  2. The cane or marine toad, Rhinella marina (Anura, Bufonidae): two genetically and morphologically distinct species.

    Science.gov (United States)

    Acevedo, Aldemar A; Lampo, Margarita; Cipriani, Roberto

    2016-04-18

    Rhinella marina is a Neotropical toad that has been introduced widely worldwide. Its toxic effects to frog-eating predators threaten the native and domestic fauna of some regions where it has been introduced. Despite previous studies suggesting two genetically distinct cryptic species within R. marina, one east and one west of the Andes, its taxonomic status remained unresolved due to the absence of morphological complementary evidence. For the first time, data from two mitochondrial genes (ND3 and CR) and 23 morphometric landmarks are combined to evaluate the taxonomic status of this species. Our results support the hypothesis of two separate evolutionary lineages within R. marina and demonstrate that these lineages have significantly diverged in skull shape. We identified two distinct morphotypes, one eastern and one Andean western, with no overlapping morphospaces. The geographic pattern of genetic variation was consistent with a stable structured population with no evidence of recent demographic or geographic expansions. The concordance between the observed geographic patterns in morphometric and genic traits calls for the recognition of two species under R. marina name.

  3. Skin Bacterial Community Reorganization Following Metamorphosis of the Fire-Bellied Toad (Bombina orientalis).

    Science.gov (United States)

    Bataille, Arnaud; Lee-Cruz, Larisa; Tripathi, Binu; Waldman, Bruce

    2017-07-19

    In organisms with complex life histories, dramatic changes in microbial community structure may occur with host development and immune system maturation. Amphibian host susceptibility to diseases such as chytridiomycosis may be affected by the reorganization of skin microbial community structure that occurs during metamorphosis. We tracked changes in the bacterial communities inhabiting skin of Korean fire-bellied toads (Bombina orientalis) that we infected as tadpoles with different strains of Batrachochytrium dendrobatidis (Bd), the pathogenic fungus that causes chytridiomycosis. We found that B. orientalis undergoes a major change in skin bacterial community composition between 5 and 15 days following metamorphosis. Richness indices and phylogenetic diversity measures began to diverge earlier, between aquatic and terrestrial stages. Our results further reveal differences in skin bacterial community composition among infection groups, suggesting that the effect of Bd infection on skin microbiome composition may differ by Bd strain. Additional studies are needed to further investigate the structural and temporal dynamics of microbiome shifts during metamorphosis in wild and captive amphibian populations. Analyses of the ontogeny of microbiome shifts may contribute to an understanding of why amphibians vary in their susceptibility to chytridiomycosis.

  4. Membranes during yolk-platelet development in oocytes of the toad Bufo marinus.

    Science.gov (United States)

    Richter, H -P

    1987-09-01

    Oocytes of the toad Bufo marinus have been studied by means of thin section and particularly freeze-fracture electron microscopy to characterize the cytoplasmic membranes around the yolk organelle, and the storage of yolk material in precursors and platelets. This appears to be a previously unknown type of yolk-platelet formation. During yolk-organelle development from the primordial precursor to the bi-partite fully grown yolk platelet, numerous lipoid droplets are attached to the periphery of the platelet, indicating an intense uptake of lipids. As is typical for amphibians, the fully grown yolk platelet has a crystalline internum covered by a dense osmiophilic externum, and the whole organelle is enveloped by a plasma membrane that shows no direct connection or fusion with endocytotic vesicles. The yolk membrane exhibits few intramembraneous particles (IMPs) at the core areas and some more where it borders fields of lipoid droplets. Here the IMPs show a net-like arrangement in the furrows between adjacent droplets.

  5. Behavioral, physiological and morphological correlates of parasite intensity in the wild Cururu toad (Rhinella icterica

    Directory of Open Access Journals (Sweden)

    Eduardo Hermógenes Moretti

    2017-12-01

    Full Text Available Large numbers of parasites are found in various organs of anuran amphibians, with parasite intensities thought to modulate the host's Darwinian fitness traits. Interaction between the anuran hosts and their multiple parasites should modulate the host's phenotypic characteristic, such as those associated with high energetic demand (such as calling effort and locomotor performance, energy balance (standard metabolic rate, and morphological plasticity (as indicated by organ masses. The present study investigated the impact of parasite intensities on the behavioral, physiological, and morphological traits of wild adult male Rhinella icterica (Anura: Bufonidae. We tested as to whether individuals with higher parasite intensities would present: 1 lower vocal calling effort in the field, as well as poorer locomotor performance and body-condition index; and 2 higher standard metabolic rates and internal organ masses. Measurements included: calling effort in the field; standard metabolic rate; locomotor performance; parasite intensity; internal organ masses (heart, liver, kidneys, intestines, stomach, lungs, hind limb muscle, and spleen; and the body-condition index. Results showed a negative association of parasite intensities with locomotor performance, and standard metabolic rate of R. icterica. A positive association between parasite intensities and relative organ masses (heart, intestines and kidneys was also evident. Toads with higher pulmonary and intestinal parasites intensities also showed higher total parasite intensities. Keywords: Bufonidae, Locomotor performance, Metabolic rate, Vocal effort, Rhabdias, Parasite association

  6. Thermal performance curves under daily thermal fluctuation: A study in helmeted water toad tadpoles.

    Science.gov (United States)

    Bartheld, José L; Artacho, Paulina; Bacigalupe, Leonardo

    2017-12-01

    Most research in physiological ecology has focused on the effects of mean changes in temperature under the classic "hot vs cold" acclimation treatment; however, current evidence suggests that an increment in both the mean and variance of temperature could act synergistically to amplify the negative effects of global temperature increase and how it would affect fitness and performance-related traits in ectothermic organisms. We assessed the effects of acclimation to daily variance of temperature on thermal performance curves of swimming speed in helmeted water toad tadpoles (Calyptocephalella gayi). Acclimation treatments were 20°C ± 0.1 SD (constant) and 20°C ± 1.5 SD (fluctuating). We draw two key findings: first, tadpoles exposed to daily temperature fluctuation had reduced maximal performance (Zmax), and flattened thermal performance curves, thus supporting the "vertical shift or faster-slower" hypothesis, and suggesting that overall swimming performance would be lower through an examination of temperatures under more realistic and ecologically-relevant fluctuating regimens; second, there was significant interindividual variation in performance traits by means of significant repeatability estimates. Our present results suggest that the widespread use of constant acclimation temperatures in laboratory experiments to estimate thermal performance curves (TPCs) may lead to an overestimation of actual organismal performance. We encourage the use of temperature fluctuation acclimation treatments to better understand the variability of physiological traits, which predict ecological and evolutionary responses to global change. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Ultrastructural and Molecular Changes in the Developing Small Intestine of the Toad Bufo regularis

    Directory of Open Access Journals (Sweden)

    S. A. Sakr

    2014-01-01

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

  8. The complete mitochondrial genome of the toad-headed lizard, Phrynocephalus forsythii (Reptilia, Squamata, Agamidae).

    Science.gov (United States)

    Shao, Min; Ma, Li; Wang, Zheng

    2016-09-01

    In this study, we report the complete mitochondrial genome of Phrynocephalus forsythii (Reptilia, Squamata, Agamidae), which is a circular molecule of 16,143 bp in size and consists of 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs and 2 non-coding sequence (D-loop). The mitogenome of P. forsythii was similar to the typical mtDNA of vertebrates in gene arrangement and composition. The control region composed of two parts: one (348 bp) between tRNA(Phe) and the other (636 bp) between tRNA(Pro) and 12S rRNA. The A + T content of overall base of the composition of H-strand is 62.0% (T: 25.6%, C: 25.7%, A: 36.3% and G: 12.3%). The whole mitogenomic sequence of P. forsythii provides powerful data to study of its phylogenetic position within toad-headed lizards.

  9. Effect of gibberellin-A3 on metamorphosis in the Egyptian toad Bufo regularis

    Directory of Open Access Journals (Sweden)

    Saber A. Sakr

    2012-05-01

    Full Text Available The present study was carried out to study the effect of gibberellin-A3 on the metamorphosis of the Egyptian toad Bufo regularis. Samples of B. regularis were collected from Shebin El-Kom, Menoufia Governorate during the breeding season and kept in aquaria with little water till spawning, fertilized eggs are divided into 2 groups of 200 eggs each. The 1st group was treated with 5 ppm of gibberellin-A3 (Berelex 3 days/week for the period of metamorphosis. The second group was left untreated under the same environmental conditions and considered as a control. Hatchability of the eggs in each group was recorded. External lengths of the total body, hind limbs and the tail were measured. As a measure of apoptotic DNA fragmentation, the presence of DNA ladder was determined. The results showed that out of 200 eggs 47.5% were hatched in the control group and 76.5% were hatched in gibberellin-A3 treated group. The average duration of metamorphosis was 60 days and 52 days in the control and treated groups, respectively. There was an increase in the total length of the hind limbs of the treated tadpole as compared with the control throughout the experimental periods. DNA isolated from control and tadpoles treated with gibberellin-A3 showed degradation into oligonucleotide fragments forming a clear laddering pattern of apoptosis, but the treated tadpoles showed an increase of DNA fragmentation.

  10. 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)

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

    2014-07-01

    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. 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). 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. In this study, the toad skins from Jiangsu province had the highest amount of bufadienolides (472.6 μg/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 μg crude drug/mL, respectively. 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.

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

    Science.gov (United States)

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

    2014-09-01

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

  12. Gene expression variations in high-altitude adaptation: a case study of the Asiatic toad (Bufo gargarizans).

    Science.gov (United States)

    Yang, Weizhao; Qi, Yin; Lu, Bin; Qiao, Liang; Wu, Yayong; Fu, Jinzhong

    2017-07-03

    Genome-wide investigation of molecular mechanisms for high-altitude adaptation has attracted great attention in the last few years. In order to understand the contribution of gene expression level variations to high-altitude adaptation in Asiatic toads (Bufo gargarizans), we implemented a reciprocal transplant experiment between low- and high-altitude sites and sequenced 12 transcriptomes from brain, heart, and liver tissues. A large number of genes with expression differences (DEGs) between high- and low-altitude individuals (193 fixed and 844 plastic) were identified, and the majority of them were tissue specific. Heart displayed the largest number of DEGs, both plastic and fixed. Fixed DEGs were particularly concentrated in functions associated with muscle contraction, and the majority of them were down-regulated in high-altitude individuals. Plastic DEGs were highly concentrated in several energy metabolism related functional categories, and the majority of them were also down-regulated at high-altitude environments. In liver samples, genes associated with nutrient metabolism experienced a broad-scale expression down-regulation in high-altitude toads. These broadly suppressed expression patterns at high altitudes are in strong contrast to those of endothermic homeotherms, suggesting poikilothermic vertebrates may have adopted different strategies at high altitudes. Our results strongly support that both genotypic specialization and phenotypic plasticity play crucial role in adaptation to high altitude for Asiatic toads. Poikilothermic vertebrates are among the most hypoxia-tolerant animals known, and many molecular mechanisms remain elusive. We hope that our results will provide useful directions for future research.

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

    Directory of Open Access Journals (Sweden)

    Adam Rick Bessa-Silva

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-08-31

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

  15. N-methyl serotonin analogues from the Bufo bufo toad venom interact efficiently with the α7 nicotinic acetylcholine receptors.

    Science.gov (United States)

    Kryukova, E V; Lebedev, D S; Ivanov, I A; Ivanov, D A; Starkov, V G; Tsetlin, V I; Utkin, Yu N

    2017-01-01

    Two low-molecular-weight compounds were isolated from the parotid gland secret of the toad Bufo bufo, which by absorption spectra and HPLC-MS/MS chromatography data correspond to di- and trimethyl derivatives of serotonin (5-hydorxytryptamine): bufotenine (confirmed by counter synthesis) and bufotenidine (5-HTQ). In experiments on competitive radioligand binding, these compounds showed a higher affinity and selectivity for neuronal α7 nicotinic acetylcholine receptors compared with the muscular cholinergic receptors. The most efficient compound in terms of binding value was bufotenine, the efficiency of 5-HTQ was an order of magnitude lower, and the minimal activity was exhibited by serotonin.

  16. [Individual variation in the development of the common toad, Bufo bufo (Anura, Bufonidae): 2. Diagnostic characters of the axial skeleton].

    Science.gov (United States)

    Kovalenko, E E; Kruzhkova, Iu I

    2013-01-01

    Analysis of individual variation in diagnostic characters of the axial skeleton has been performed in all offspring (1633 ind.) from the same spawn of one pair of common toads under conditions of laboratory rearing, with natural elimination being reduced to a minimum. More than 50 skeletal anomalies have been recorded. Factual data are presented that characterize deviations from the species norm in the frequency of "background anomalies" (Kovalenko, 2003). Correlations between manifestations of different variants of character states are considered. The problem of norm and anomaly in individual variation is discussed.

  17. The dynamics of venous return and response to hypervolemia in the toad, Bufo marinus (L.)

    Science.gov (United States)

    Killorn, Erin E; Toews, Daniel P

    2001-01-01

    Background Venous return from the posterior region of amphibians travels by either two renal portal veins to the kidney or a central abdominal vein that drains into the hepatic portal system. The relative proportions of blood flow in these vessels has never been measured nor has a modification of flow been determined when venous return increases by changes in blood volume during hypervolemia or during increased volume input from the posterior lymph hearts. Results Venous return from the posterior region of Bufo marinus was measured under resting conditions and in response to a systemic hypervolemia. Doppler flow probes were positioned on the renal portal and ventral abdominal veins, and flow was recorded as injections of artificial plasma equaling 100% of the animal's plasma volume were administered through the sciatic artery. Resting flow was found to be 5.54 ± 2.03 ml min-1 kg-1 in the paired renal portal veins, and 7.31 ± 0.89 ml min-1 kg-1 in the ventral abdominal vein. While renal portal flow was found to increase by a factor of 2.4 times during the first 10 min of hypervolemia, ventral abdominal flow only increased by a factor of 1.3. Conclusions Our results quantify the contribution to circulation from posterior venous return in the toad Bufo marinus. A preferential movement of excess fluid through the renal portal pathway was also demonstrated, supporting the possibility of water elimination via the renal portal circulation, especially during periods of high water influx into the animals. PMID:11696249

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-03-01

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

  19. Malformations and mortality in the Asian Common Toad induced by exposure to pleurolophocercous cercariae (Trematoda: Cryptogonimidae).

    Science.gov (United States)

    Jayawardena, Uthpala A; Tkach, Vasyl V; Navaratne, Ayanthi N; Amerasinghe, Priyanie H; Rajakaruna, Rupika S

    2013-06-01

    Malformations and increased mortality due to infection by the digenetic trematode, Riberioa ondatrae have been reported for many species of amphibians. Severe malformations have also been reported in the Common Hourglass Tree Frog, Polypedates cruciger induced by pleurolophocercous cercariae in Sri Lanka in addition to the changes in the behaviour, development and survival of the host. We exposed pre-limb bud stage tadpoles (Gosner stages 25-26) of the Asian Common Toad, Duttaphrynus melanostictus to the same pleurolophocercous type cercariae under laboratory conditions. Molecular and morphological identification showed that these cercariae belonged Acanthostomum burminis infecting freshwater snakes as definitive hosts. These cercariae induced malformations (27.8%) and reduced survival to metamorphosis (53.8%). The magnitude of the effects increased with the dose of cercariae. Types of malformations were mainly axial, such as scoliosis and kyphosis. Severe limb malformations such as extra or missing limbs as reported for amphibians exposed to R. ondatrae were not observed in the D. melanostictus. Same authors reported a higher percentage of malformations previously when P. cruciger was exposed to the cercariae A. burminis compared to D. melanostictus. However, tadpoles of D. melanostictus, which are smaller compared to those of P. cruciger, experienced higher mortality than P. cruciger tadpoles. Trematode induced malformations and mortality in amphibians are highly variable and depend on multiple factors such as host species differences such as resistance to infection and tolerance, life-history characteristics such as size at metamorphosis and length of the metamorphosis period, and other factors such as size of the amphibian at the time of trematode exposure. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  20. Monoaminergic integration of diet and social signals in the brains of juvenile spadefoot toads.

    Science.gov (United States)

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

    2017-09-01

    Social behavior often includes the production of species-specific signals (e.g. mating calls or visual displays) that evoke context-dependent behavioral responses from conspecifics. Monoamines are important neuromodulators that have been implicated in context-dependent social behavior, yet we know little about the development of monoaminergic systems and whether they mediate the effects of early life experiences on adult behavior. We examined the effects of diet and social signals on monoamines early in development in the plains spadefoot toad (Spea bombifrons), a species in which diet affects the developmental emergence of species recognition and body condition affects the expression of adult mating preferences. To do so, we manipulated the diet of juveniles for 6 weeks following metamorphosis and collected their brains 40 min following the presentation of either a conspecific or a heterospecific call. We measured levels of monoamines and their metabolites using high pressure liquid chromatography from tissue punches of the auditory midbrain (i.e. torus semicircularis), hypothalamus and preoptic area. We found that call type affected dopamine and noradrenaline signaling in the auditory midbrain and that diet affected dopamine and serotonin in the hypothalamus. In the preoptic area, we detected an interaction between diet and call type, indicating that diet modulates how the preoptic area integrates social information. Our results suggest that the responsiveness of monoamine systems varies across the brain and highlight preoptic dopamine and noradrenaline as candidates for mediating effects of early diet experience on later expression of social preferences. © 2017. Published by The Company of Biologists Ltd.

  1. CRYPTIC NEOGENE VICARIANCE AND QUATERNARY DISPERSAL OF THE RED-SPOTTED TOAD (BUFO PUNCTATUS) INSIGHTS ON THE EVOLUTION OF NORTH AMERICAN WARM DESERT BIOTAS

    Science.gov (United States)

    We define the geographic distributions of embedded evolutionary mitochondrial DNA (mtDNA) lineages (clades) within a broadly distributed, arid- dwelling toad, Bufo punctatus, and evaluate these patterns as they relate to hypothesized vicariant events leading to the formation of b...

  2. Arginine derivatives of dicarboxylic acids from the parotid gland secretions of common toad Bufo bufo-New agonists of ionotropic γ-aminobutyric acid receptors.

    Science.gov (United States)

    Lebedev, D S; Ivanov, I A; Kryukova, E V; Starkov, V G; Tsetlin, V I; Utkin, Yu N

    2017-05-01

    Compounds activating γ-aminobutyric acid type A receptor were isolated from the toad Bufo bufo venom as a result of chromatographic separation. Analysis of the structure of these compounds by mass spectrometry and nuclear magnetic resonance showed that they are arginine derivatives of dicarboxylic acids and represent suberylarginine, pimeloylarginine, and adipoylarginine.

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

    DEFF Research Database (Denmark)

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

    1994-01-01

    Incorporation of (32P) phosphate and (14C) acetate into frog (Rana temporaria) skin phospholipids in vitro was positively correlated to skin MR cell density. Transport across toad (Bufo bufo) skin and incorporation into skin phospholipids of the radioactive tracers were independent...

  4. Quantifying anuran microhabitat use to infer the potential for parasite transmission between invasive cane toads and two species of Australian native frogs.

    Science.gov (United States)

    Pizzatto, Lígia; Both, Camila; Shine, Richard

    2014-01-01

    Parasites that are carried by invasive species can infect native taxa, with devastating consequences. In Australia, invading cane toads (Rhinella marina) carry lungworm parasites (Rhabdias pseudosphaerocephala) that (based on previous laboratory studies) can infect native treefrogs (Litoria caerulea and L. splendida). To assess the potential of parasite transmission from the invader to the native species (and from one infected native frog to another), we used surveys and radiotelemetry to quantify anuran microhabitat use, and proximity to other anurans, in two sites in tropical Australia. Unsurprisingly, treefrogs spent much of their time off the ground (especially by day, and in undisturbed forests) but terrestrial activity was common at night (especially in anthropogenically modified habitats). Microhabitat overlap between cane toads and frogs was generally low, except at night in disturbed areas, whereas overlap between the two frog species was high. The situations of highest overlap, and hence with the greatest danger of parasite transmission, involve aggregations of frogs within crevices by day, and use of open ground by all three anuran species at night. Overall, microhabitat divergence between toads and frogs should reduce, but not eliminate, the transmission of lungworms from invasive toads to vulnerable native frogs.

  5. Bufadienolides from parotoid gland secretions of Cuban toad Peltophryne fustiger (Bufonidae): Inhibition of human kidney Na(+)/K(+)-ATPase activity.

    Science.gov (United States)

    Perera Córdova, Wilmer H; Leitão, Suzana Guimarães; Cunha-Filho, Geraldino; Bosch, Roberto Alonso; Alonso, Isel Pascual; Pereda-Miranda, Rogelio; Gervou, Rodrigo; Touza, Natália Araújo; Quintas, Luis Eduardo M; Noël, François

    2016-02-01

    Parotoid gland secretions of toad species are a vast reservoir of bioactive molecules with a wide range of biological properties. Herein, for the first time, it is described the isolation by preparative reversed-phase HPLC and the structure elucidation by NMR spectroscopy and/or mass spectrometry of nine major bufadienolides from parotoid gland secretions of the Cuban endemic toad Peltophryne fustiger: ψ-bufarenogin, gamabufotalin, bufarenogin, arenobufagin, 3-(N-suberoylargininyl) marinobufagin, bufotalinin, telocinobufagin, marinobufagin and bufalin. In addition, the secretion was analyzed by UPLC-MS/MS which also allowed the identification of azelayl arginine. The effect of arenobufagin, bufalin and ψ-bufarenogin on Na(+)/K(+)-ATPase activity in a human kidney preparation was evaluated. These bufadienolides fully inhibited the Na(+)/K(+)-ATPase in a concentration-dependent manner, although arenobufagin (IC50 = 28.3 nM) and bufalin (IC50 = 28.7 nM) were 100 times more potent than ψ-bufarenogin (IC50 = 3020 nM). These results provided evidence about the importance of the hydroxylation at position C-14 in the bufadienolide skeleton for the inhibitory activity on the Na(+)/K(+)-ATPase. Published by Elsevier Ltd.

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

    Science.gov (United States)

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

    2014-01-01

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

  7. Molecular phylogenetics and historical biogeography of the west-palearctic common toads (Bufo bufo species complex).

    Science.gov (United States)

    Garcia-Porta, J; Litvinchuk, S N; Crochet, P A; Romano, A; Geniez, P H; Lo-Valvo, M; Lymberakis, P; Carranza, S

    2012-04-01

    In most pan-Eurasiatic species complexes, two phenomena have been traditionally considered key processes of their cladogenesis and biogeography. First, it is hypothesized that the origin and development of the Central Asian Deserts generated a biogeographic barrier that fragmented past continuous distributions in Eastern and Western domains. Second, Pleistocene glaciations have been proposed as the main process driving the regional diversification within each of these domains. The European common toad and its closest relatives provide an interesting opportunity to examine the relative contributions of these paleogeographic and paleoclimatic events to the phylogeny and biogeography of a widespread Eurasiatic group. We investigate this issue by applying a multiproxy approach combining information from molecular phylogenies, a multiple correspondence analysis of allozyme data and species distribution models. Our study includes 304 specimens from 164 populations, covering most of the distributional range of the Bufo bufo species complex in the Western Palearctic. The phylogenies (ML and Bayesian analyses) were based on a total of 1988 bp of mitochondrial DNA encompassing three genes (tRNAval, 16S and ND1). A dataset with 173 species of the family Bufonidae was assembled to estimate the separation of the two pan-Eurasiatic species complexes of Bufo and to date the main biogeographic events within the Bufo bufo species complex. The allozyme study included sixteen protein systems, corresponding to 21 presumptive loci. Finally, the distribution models were based on maximum entropy. Our distribution models show that Eastern and Western species complexes are greatly isolated by the Central Asian Deserts, and our dating estimates place this divergence during the Middle Miocene, a moment in which different sources of evidence document a major upturn of the aridification rate of Central Asia. This climate-driven process likely separated the Eastern and Western species. At the

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

    Directory of Open Access Journals (Sweden)

    Thomé Maria Tereza C

    2012-12-01

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

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

    Science.gov (United States)

    2012-01-01

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

  10. Effects of membrane cholesterol manipulation on excitation-contraction coupling in skeletal muscle of the toad.

    Science.gov (United States)

    Launikonis, B S; Stephenson, D G

    2001-07-01

    1. Single mechanically skinned fibres and intact bundles of fibres from the twitch region of the iliofibularis muscle of cane toads were used to investigate the effects of membrane cholesterol manipulation on excitation-contraction (E-C) coupling. The cholesterol content of membranes was manipulated with methyl-beta-cyclodextrin (MbetaCD). 2. In mechanically skinned fibres, depletion of membrane cholesterol with MbetaCD caused a dose- and time-dependent decrease in transverse tubular (t)-system depolarization-induced force responses (TSDIFRs). TSDIFRs were completely abolished within 2 min in the presence of 10 mM MbetaCD but were not affected after 2 min in the presence of a 10 mM MbetaCD-1 mM cholesterol complex. There was a very steep dependence between the change in TSDIFRs and the MbetaCD : cholesterol ratio at 10 mM MbetaCD, indicating that the inhibitory effect of MbetaCD was due to membrane cholesterol depletion and not to a pharmacological effect of the agent. Tetanic responses in bundles of intact fibres were abolished after 3-4 h in the presence of 10 mM MbetaCD. 3. The duration of TSDIFRs increased markedly soon (laser scanning microscopy revealed that the integrity of the t-system was not compromised by either intra- or extracellular application of 10 mM MbetaCD and that a large [Ca(2+)] gradient was maintained across the t-system. 5. Membrane cholesterol depletion caused rapid depolarization of the polarized t-system as shown independently by spontaneous TSDIFRs induced by MbetaCD and by changes in the fluorescence intensity of an anionic potentiometric dye (DiBAC(4)(3)) in the presence of MbetaCD. This rapid depolarization of the t-system by cholesterol depletion was not prevented by blocking the Na(+) channels with TTX (10 microM) or the L-type Ca(2+) channels with Co(2+) (5 mM). 6. The results demonstrate that cholesterol is important for maintaining the functional integrity of the t-system and sarcoplasmic reticulum, probably by having specific

  11. Single Ca(2+)-activated Cl(-) channel currents recorded from toad olfactory cilia.

    Science.gov (United States)

    Delgado, Ricardo; Mura, Casilda V; Bacigalupo, Juan

    2016-04-25

    Odor transduction, occurring in the chemosensory cilia of vertebrate olfactory sensory neurons, is triggered by guanosine triphosphate-coupled odor receptors and mediated by a cyclic adenosine monophosphate (cAMP) signaling cascade, where cAMP opens cationic non-selective cyclic nucleotide-gated (CNG) channels. Calcium enters through CNG gates Ca(2+)-activated Cl(-) channels, allowing a Cl(-) inward current that enhances the depolarization initiated by the CNG-dependent inward current. The anoctamin channel 2, ANO2, is considered the main Ca(2+)-activated Cl(-) channel of olfactory transduction. Although Ca(2+)-activated Cl(-) channel-dependent currents in olfactory sensory neurons were reported to be suppressed in ANO2-knockout mice, field potentials from their olfactory epithelium were only modestly diminished and their smell-dependent behavior was unaffected, suggesting the participation of additional Ca(2+)-activated Cl(-) channel types. The Bestrophin channel 2, Best2, was also detected in mouse olfactory cilia and ClCa4l, belonging to the ClCa family of Ca(2+)-activated Cl(-) channels, were found in rat cilia. Best2 knock-out mice present no electrophysiological or behavioral impairment, while the ClCa channels have not been functionally studied; therefore, the overall participation of all these channels in olfactory transduction remains unresolved. We explored the presence of detectable Ca(2+)-activated Cl(-) channels in toad olfactory cilia by recording from inside-out membrane patches excised from individual cilia and detected unitary Cl(-) current events with a pronounced Ca(2+) dependence, corresponding to 12 and 24 pS conductances, over tenfold higher than the aforementioned channels, and a approx. fivefold higher Ca(2+) affinity (K0.5 = 0.38 µM). Remarkably, we observed immunoreactivity to anti-ClCa and anti-ANO2 antibodies in the olfactory cilia, suggesting a possible cooperative function of both channel type in chemotransduction. These results

  12. Spatial spread of activation and background desensitization in toad rod outer segments.

    Science.gov (United States)

    Lamb, T D; McNaughton, P A; Yau, K W

    1981-01-01

    1. The spread of activation and background desensitization in rods was studied by recording membrane current from single outer segments in pieces of isolated toad retina.2. Flash sensitivity changed slightly along the outer segment, falling by about 30% from base to tip.3. When only the distal half of an outer segment was in the recording pipette, illumination of the unrecorded part elicited little or no photocurrent at the recorded part, indicating that a photoisomerization does not cause activation of the entire outer segment.4. With diffuse illumination of an outer segment fully drawn into the pipette, the intensity-response relations at fixed times were invariant in form for most of the rising phase of the flash response and were considerably steeper than the Michaelis relation. The observed relation was consistent with a model in which a photoisomerization blocks all channels over a short region of the outer segment.5. With illumination restricted to a narrow transverse slit, the intensity-response relations at fixed times were much less steep, as would be expected for a very limited longitudinal spread of activation. An upper limit for the effective longitudinal diffusion coefficient of the internal transmitter was estimated to be about 3 x 10(-7) cm(2) sec(-1). This corresponds to a space constant for longitudinal spread of transmitter of about 3 mum at the time of the dim response peak.6. The time course of flash responses elicited with light positioned either on the edge or on the centre of the outer segment was very similar.7. Desensitization resulting from steady illumination by a transverse slit was also localized longitudinally. A linear desensitization parameter T, defined in Results, decayed approximately exponentially along the outer segment, on either side of the site of photoisomerization, with a space constant of about 6 mum.8. Transverse spread of desensitization was more effective than longitudinal spread.9. After turning off a dim diffuse

  13. Effects of Petrol Exposure on Glucose, Liver and Muscle glycogen levels in the Common African toad Bufo regularis.

    Science.gov (United States)

    Isehunwa, G O; Yusuf, I O; Alada, A Ar

    2017-03-06

    This study investigated the effects of exposure to petrol on blood glucose, liver and muscle glycogen levels in the common African toad Bufo regularis. A total of 126 adult toads of either sex weighing between 70-100g were used for this study. The experiment was divided into three phases. The phase 1 experiment the acute toxicity test consisted of animals divided into six groups of 10 toads per group and were exposed to water (H2O), H2O + Tween 80, 2ml/l, 3ml/l, 5ml/l, and 10ml/l of petrol respectively for 96 hours using the static renewal bioassay system. In the Phase 2 experiment, the animals were exposed to H2O, H2O + Tween 80, 0.14ml/l, 0.3ml/l, 0.6ml/l, and 1.13ml/l of petrol respectively for 3 days; while in phase 3 experiment they were exposed to petrol solutions for 14 days. After the various exposures, the blood glucose, liver and muscle glycogen contents were determined using standard methods. The results of the study showed that the median lethal concentration of petrol (96 hours LC50) was 4.5ml/l and sub-lethal concentration of petrol caused mortality of animals. Exposure to petrol solutions for 3 days had no significant effect on blood glucose level of the animals but caused significant decrease in the liver and muscle glycogen levels at high concentrations. In the animals exposed to petrol solutions for 14 days, there was a significant increase in glucose levels and significant reduction in liver and muscle glycogen levels at high concentrations when compared with the control. The results show that sub-lethal concentrations of petrol can cause mortality of animals, hyperglycemia and reduction in liver and muscle glycogen levels. The effects of petrol exposure on carbohydrate metabolism depend on the concentration and duration of exposure.

  14. EFFECTS OF CHRONIC CADMIUM EXPOSURE ON METAMORPHOSIS, SKELETAL DEVELOPMENT AND THYROID ENDOCRINE DISRUPTION IN CHINESE TOAD BUFO GARGARIZANS TADPOLES.

    Science.gov (United States)

    Sun, Nailiang; Wang, Hongyuan; Ju, Zongqi; Zhao, Hongfeng

    2017-08-11

    The study examined the effects of chronic cadmium exposure on metamorphosis, body size, thyroid gland, and skeletal development of Chinese toad (Bufo gargarizans) tadpoles. Tadpoles were exposed to cadmium concentrations at 0, 5, 10, 50,100 and 500 μg/L from Gonser stage 26 to Gosner stage 46 of completion of metamorphosis. Our results showed 100 and 500 μg/L cadmium concentrations increased mortality and decelerated metamorphosis rate. In addition, significant body size reduction at Gosner stage 42 was observed at 100 and 500 μg/L cadmium treatments (p Bufo gargarizans larvae. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  15. [Specific features of the melanophore system in different color morphs of larvae of the common toad (Bufo bufo L.)].

    Science.gov (United States)

    Zakharova, L A; Surova, G S; Timofeev, K N

    2012-01-01

    In a natural pond among usual black larvae of the common toad (Bufo bufo L.), a few unusual individuals of red-olive coloring were found out. In both morphs we investigated the melanophores of skin using different methods. The ESR-spectrometric analysis has shown the absence of distinctions between morphs by the amount of melanin. Analysis of total preparations of skin has shown the presence of various kinds of melanophore cells both in the derma and in the epidermis. Among typical melanophores, essentially differing cells appeared (atypical cells). In black morph tadpoles, the number of all kinds of melanophores is significantly greater than in red-olive morphs. It is shown that dark coloring is connected with a considerable number of atypical cells in the epidermis imposed on a dense layer of typical dermal melanophores with dispersed melanin.

  16. Heritability of Batrachochytrium dendrobatidis burden and its genetic correlation with development time in a population of Common toad (Bufo spinosus).

    Science.gov (United States)

    Palomar, Gemma; Bosch, Jaime; Cano, José Manuel

    2016-10-01

    Despite the important threat that emerging pathogens pose for the conservation of biodiversity as well as human health, very little is known about the adaptive potential of host species to withstand infections. We studied the quantitative genetic architecture responsible for the burden of the fungal pathogen Batrachochytrium dendrobatidis in a population of common toads in conjunction with other life-history traits (i.e., body size and development rate) that may be affected by common selective pressures. We found a significant heritable component that is associated with fungal burden, which may allow for local adaptation to this pathogen to proceed. In addition, the high genetic correlation found between fungal burden and development time suggests that both traits have to be taken into account in order to assess the adaptive response of host populations to this emerging pathogen. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

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

    DEFF Research Database (Denmark)

    Kristensen, P; Larsen, Erik Hviid

    1978-01-01

    Substitution of chloride in the outside bathing medium of the toad skin with bromide, iodide, nitrate and sulphate leads to a reduction in the apparent exchange diffusion of chloride across this tissue, and also to a reduction of the chloride current recorded during hyperpolarization. A series...... of inhibitors (thiocyanate, furosemide, phloretin, and acetazolamide) also affects chloride exchange diffusion, hyperpolarization current as well as chloride influx during hyperpolarization. Although in some cases, effects on the short circuit current were also observed none of the effects on chloride transport....... On the basis of these findings, and the results reported in the previous paper (Hviid Larsen and Kristensen 1977) it is considered probable that the membrane molecules responsible to chloride exchange diffusion under short circuit conditions, are rearranged under the influence of a hyperpolarizing clamping...

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

    Directory of Open Access Journals (Sweden)

    Čađenović Natalija

    2013-01-01

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

  19. Retina damage after exposure to UVA radiation on the early developmental stages of the Egyptian toad Bufo regularis Reuss

    Directory of Open Access Journals (Sweden)

    Alaa El-Din H. Sayed

    2016-10-01

    Full Text Available The present study was carried out to investigate the histological and histochemical changes in the retina on different developmental stages of Egyptian toad Bufo regularis. Our experiment started when tadpoles begin to feed. The adapted embryos are divided into 3 large tanks of 200 embryos each, collections of samples started from feeding age every three days. Both histological and histochemical results showed that the general architecture of the retina organ is correlated with the state of development. Therefore, it displayed different characteristic features depending on the investigated developmental stage starting from the larval stage (feeding began, stage 44 and ending with the post-metamorphic stage 66. Also, the present work aimed to study the chronic effects of UVA on the retina structure of B. regularis during development and metamorphosis for the first time.

  20. Disproportionate distribution of field potentials across the toad's tectal visual map in response to diffuse light ON and OFF stimulations.

    Science.gov (United States)

    Schwippert, W W; Beneke, T W; Ewert, J P

    1996-01-01

    In toads Bufo marinus and Bufo bufo spinosus, field potentials (FPs) were recorded from the surface of the optic tectum at different sites of the visual map in response to a sudden diffuse darkening (OFF) and lightening (ON) of the visual field of the contralateral eye. The OFF and ON responses were differently pronounced or even failed to occur. The latency of the former was significantly less than the one of the latter. FP amplitudes of the OFF and ON responses were strongest in the representation of a horizonto-superior anterio-lateral portion of the visual field and weakest toward the posterior field of vision. This phenomenon suggests various interpretations for subsequent experiments.

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

    Science.gov (United States)

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

    2014-01-01

    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.

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

    Science.gov (United States)

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

    2014-05-01

    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. Copyright © 2014 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Haley BOWCOCK, Gregory P. BROWN, Richard SHINE

    2013-12-01

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

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

    Science.gov (United States)

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

    1986-06-01

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

  5. Effects of a glyphosate-based herbicide on the development of Common toads (Bufo bufo L.; Amphibia) at different temperatures

    Science.gov (United States)

    Baier, Fabian; Gruber, Edith; Spangl, Bernhard; Zaller, Johann G.

    2016-04-01

    Herbicides based on the active ingredient glyphosate are frequently applied in agriculture, horticulture and private gardens all over the world. Recently, leaching of glyphosate or its metabolite (AMPA) into water bodies inhabited by amphibians has been reported. However, very little is known about non-target effects of these herbicides on amphibians and even less is known to what extent different temperatures might alter these effects. Using climate chambers, we investigated the effects of the glyphosate-based herbicide Roundup PowerFlex® (480 g L-1 glyphosate, formulated as 588 g L-1 potassium salt) on the larval development of Common toads (Bufo bufo L.; Amphibia: Anura) under different temperature regimes (15°C vs. 20°C). We established five herbicide concentrations: 0, 1.5, 3, 4 mg acid equivalent L-1 and a 4 mg a.e. L-1 pulse treatment (totally three applications of 1.5, 1.5 and another 1 mg a.e. L-1) at each temperature in a full-factorial design. Each treatment combination was replicated five times, the experiment ran for 24 days. Results showed a highly significant effect of temperature on body length and body width but no effect of herbicide concentration on these growth parameters. Moreover, highly significant interactions between herbicide and temperature on body length and body width were observed suggesting that herbicides had different effects on different temperatures. In conclusion, although Roundup PowerFlex® at the tested concentrations appeared to have no acute toxicity to larvae of Common toads, the observed effects on tadpole morphology will potentially affect competitive interactions in spawning ponds of amphibia. Our findings of herbicide x temperature interactions might become more prevalent when human-induced climate change will lead to more extreme temperatures.

  6. Metabolic evidence that serosal sodium does not recycle through the active transepithelial transport pathway of toad bladder.

    Science.gov (United States)

    Canessa, M; Labarca, P; Leaf, A

    1976-12-25

    The possibility that sodium from the serosal bathing medium "back diffuses" into the active sodium transport pool within the mucosal epithelial cell of the isolated toad bladder was examined by determining the effect on the metabolism of the tissue of removing sodium from the serosal medium. It was expected that if recycling of serosal sodium did occur through the active transepithelial transport pathway of the isolated toad bladder, removal of sodium from the serosal medium would reduce the rate of CO2 production by the tissue and enhance of stoichiometric ratio of sodium ions transported across the bladder per molecula of sodium transport dependent CO2 produced simultaneously by the bladder (JNa/JCO2). The data revealed no significant change in this ratio (17.19 with serosal sodium and 16.13 after replacing serosal sodium with choline). Further, when transepithelial sodium transport was inhibited (a) by adding amiloride to the mucosal medium, or (b) by removing sodium from the mucosal medium, subsequent removal of sodium from the serosal medium, or (c) addition of ouabain failed to depress the basal rate of CO2 production by the bladder [(a)rate of basal, nontransport related, CO2 production (JbCO2) equals 1.54 +/- 0.52 with serosal sodium and 1.54 +/- 0.37 without serosal sodium; (b) Jb CO2 equals 2.18 +/- 0.21 with serosal sodium and 2.09 +/- 0.21 without serosal sodium; (c) 1.14 +/- 0.26 without ouabain and 1.13 +/- 0.25 with ouabain; unite of JbCO2 are nmoles mg d.w.-1 min-1]. The results support the hypothesis that little, if any, recycling of serosal sodium occurs in the total bladder.

  7. Wild cane toads (Rhinella marina expel foreign matter from the coelom via the urinary bladder in response to internal injury, endoparasites and disease.

    Directory of Open Access Journals (Sweden)

    Crystal Kelehear

    Full Text Available Dissections of >1,200 wild-caught cane toads (Rhinella marina in tropical Australia confirm a laboratory report that anurans can expel foreign objects from the coelom by incorporating them into the urinary bladder. The foreign objects that we found inside bladders included a diverse array of items (e.g., grass seeds, twigs, insect prey, parasites, many of which may have entered the coelom via rupture of the gut wall. In some cases, the urinary bladder was fused to other organs including liver, fat bodies, ovaries, Bidder's organs, lungs, mesentery, stomach wall, gall bladder, and the abdominal wall. Acanthocephalan parasites (of a range of developmental stages were identified from the walls of the urinary bladders of three cane toads. This organ may play a significant role in destroying or excreting metazoan parasites, as well as inanimate objects.

  8. Wild cane toads (Rhinella marina) expel foreign matter from the coelom via the urinary bladder in response to internal injury, endoparasites and disease.

    Science.gov (United States)

    Kelehear, Crystal; Jones, Hugh I; Wood, Benjamin A; Shine, Richard

    2015-01-01

    Dissections of >1,200 wild-caught cane toads (Rhinella marina) in tropical Australia confirm a laboratory report that anurans can expel foreign objects from the coelom by incorporating them into the urinary bladder. The foreign objects that we found inside bladders included a diverse array of items (e.g., grass seeds, twigs, insect prey, parasites), many of which may have entered the coelom via rupture of the gut wall. In some cases, the urinary bladder was fused to other organs including liver, fat bodies, ovaries, Bidder's organs, lungs, mesentery, stomach wall, gall bladder, and the abdominal wall. Acanthocephalan parasites (of a range of developmental stages) were identified from the walls of the urinary bladders of three cane toads. This organ may play a significant role in destroying or excreting metazoan parasites, as well as inanimate objects.

  9. Volunteer Conservation Action Data Reveals Large-Scale and Long-Term Negative Population Trends of a Widespread Amphibian, the Common Toad (Bufo bufo).

    Science.gov (United States)

    Petrovan, Silviu O; Schmidt, Benedikt R

    2016-01-01

    Rare and threatened species are the most frequent focus of conservation science and action. With the ongoing shift from single-species conservation towards the preservation of ecosystem services, there is a greater need to understand abundance trends of common species because declines in common species can disproportionately impact ecosystems function. We used volunteer-collected data in two European countries, the United Kingdom (UK) and Switzerland, since the 1970s to assess national and regional trends for one of Europe's most abundant amphibian species, the common toad (Bufo bufo). Millions of toads were moved by volunteers across roads during this period in an effort to protect them from road traffic. For Switzerland, we additionally estimated trends for the common frog (Rana temporaria), a similarly widespread and common amphibian species. We used state-space models to account for variability in detection and effort and included only populations with at least 5 years of data; 153 populations for the UK and 141 for Switzerland. Common toads declined continuously in each decade in both countries since the 1980s. Given the declines, this common species almost qualifies for International Union for the Conservation of Nature (IUCN) red-listing over this period despite volunteer conservation efforts. Reasons for the declines and wider impacts remain unknown. By contrast, common frog populations were stable or increasing in Switzerland, although there was evidence of declines after 2003. "Toads on Roads" schemes are vital citizen conservation action projects, and the data from such projects can be used for large scale trend estimations of widespread amphibians. We highlight the need for increased research into the status of common amphibian species in addition to conservation efforts focusing on rare and threatened species.

  10. [Individual variation in the development of the common toad, Bufo bufo (Anura, Bufonidae): I. Timing of development and anomalies of external structure].

    Science.gov (United States)

    Kovalenko, E E; Kruzhkova, Iu I

    2013-01-01

    Parameters of development have been analyzed in all offspring (1633 ind.) from the same spawn of one pair of common toads under conditions of laboratory rearing, with natural elimination being reduced to a minimum. The results show that the range of developmental options for the species is much wider than it follows from the standard tables of development. "Background anomalies" (Kovalenko, 2003) in the external structure of developing larvae are described and their probable frequencies under nearly optimal conditions are indicated.

  11. [Individual variation in the development of the common toad, Bufo bufo (Anura, Bufonidae): 3. Limitations of individual variation and their causes].

    Science.gov (United States)

    Kovalenko, E E; Kruzhkova, Iu I

    2013-01-01

    The results of studies on the axial skeleton of the common toad (a model species) have been used to analyze factual limitations of individual variations. The results show that the states of the studied characters do not freely combine with each other but are subject to certain morphogenetic limitations. The causes of most these limitations have been revealed during the study. Classification of the main factors limiting individual variation in the course of development is presented.

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

    Science.gov (United States)

    Van Bocxlaer, Ines; Biju, SD; Loader, Simon P; Bossuyt, Franky

    2009-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Bossuyt Franky

    2009-06-01

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

  14. First record of the silver-cheeked toad fish Lagocephalus scleratus (Gmelin, 1789 (Actinopterygii: Tetraodontidae from Chennai coastal waters, Southeast India

    Directory of Open Access Journals (Sweden)

    Krishnan Silambarasan

    2017-04-01

    Full Text Available The silver-cheeked toad fish, Lagocephalus scleratus, was recorded for the first time on 25 September 2014. Two specimens of this fish species were collected from the by-catch landed by a commercial deep-sea trawler at Kasimedu Fishing Harbour, Chennai coast, Southeast India. The morphometric and meristic characters of the recorded specimens are described and discussed. The specimen was compared with earlier reports.

  15. Moving south: effects of water temperatures on the larval development of invasive cane toads (Rhinella marina) in cool-temperate Australia.

    Science.gov (United States)

    Wijethunga, Uditha; Greenlees, Matthew; Shine, Richard

    2016-10-01

    The distributional limits of many ectothermic species are set by thermal tolerances of early-developmental stages in the life history; embryos and larvae often are less able to buffer environmental variation than are conspecific adults. In pond-breeding amphibians, for example, cold water may constrain viability of eggs and larvae, even if adults can find suitable thermal conditions in terrestrial niches. Invasive species provide robust model systems for exploring these questions, because we can quantify thermal challenges at the expanding range edge (from field surveys) and larval responses to thermal conditions (in the laboratory). Our studies on invasive cane toads (Rhinella marina) at the southern (cool-climate) edge of their expanding range in Australia show that available ponds often average around 20°C during the breeding period, 10°C lower than in many areas of the toads' native range, or in the Australian tropics. Our laboratory experiments showed that cane toad eggs and larvae cannot develop successfully at 16°C, but hatching success and larval survival rates were higher at 20°C than in warmer conditions. Lower temperatures slowed growth rates, increasing the duration of tadpole life, but also increased metamorph body mass. Water temperature also influenced metamorph body shape (high temperatures reduced relative limb length, head width, and body mass) and locomotor performance (increased speed from intermediate temperatures, longer hops from high temperatures). In combination with previous studies, our data suggest that lower water temperatures may enhance rather than reduce recruitment of cane toads, at least in areas where pond temperatures reach or exceed 20°C. That condition is fulfilled over a wide area of southern Australia, suggesting that the continuing expansion of this invasive species is unlikely to be curtailed by the impacts of relatively low water temperatures on the viability of early life-history stages.

  16. Telencephalic Neuronal Activation Associated with Spatial Memory in the Terrestrial Toad Rhinella arenarum: Participation of the Medial Pallium during Navigation by Geometry.

    Science.gov (United States)

    Sotelo, María Inés; Daneri, M Florencia; Bingman, Verner Peter; Muzio, Rubén N

    2016-01-01

    Amphibians are central to discussions of vertebrate evolution because they represent the transition from aquatic to terrestrial life, a transition with profound consequences for the selective pressures shaping brain evolution. Spatial navigation is one class of behavior that has attracted the interest of comparative neurobiologists because of the relevance of the medial pallium/hippocampus, yet, surprisingly, in this regard amphibians have been sparsely investigated. In the current study, we trained toads to locate a water goal relying on the boundary geometry of a test environment (Geometry-Only) or boundary geometry coupled with a prominent, visual feature cue (Geometry-Feature). Once learning had been achieved, the animals were given one last training session and their telencephali were processed for c-Fos activation. Compared to control toads exposed to the test environment for the first time, geometry-only toads were found to have increased neuronal labeling in the medial pallium, the presumptive hippocampal homologue, while geometry-feature toads were found to have increased neuronal labeling in the medial, dorsal, and lateral pallia. The data indicate medial pallial participation in guiding navigation by environmental geometry and lateral, and to a lesser extent dorsal, pallial participation in guiding navigation by a prominent visual feature. As such, participation of the medial pallium/hippocampus in spatial cognition appears to be a conserved feature of terrestrial vertebrates even if their life history is still tied to water, a brain-behavior feature seemingly at least as ancient as the evolutionary transition to life on land. © 2016 S. Karger AG, Basel.

  17. 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)

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

    2008-05-01

    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 Bufo bufo gargarizans for genotoxicity assessment of herbicides.

  18. Polyphyly of Asian Tree Toads, Genus Pedostibes Günther, 1876 (Anura: Bufonidae), and the Description of a New Genus from Southeast Asia.

    Science.gov (United States)

    Chan, Kin Onn; Grismer, L Lee; Zachariah, Anil; Brown, Rafe M; Abraham, Robin Kurian

    2016-01-01

    The Asian Tree Toad genus Pedostibes, as currently understood, exhibits a conspicuously disjunct distribution, posing several immediate questions relating to the biogeography and taxonomy of this poorly known group. The type species, P. tuberculosus and P. kempi, are known only from India, whereas P. hosii, P. rugosus, and P. everetti are restricted to Southeast Asia. Several studies have shown that these allopatric groups are polyphyletic, with the Indian Pedostibes embedded within a primarily South Asian clade of toads, containing the genera Adenomus, Xanthophryne, and Duttaphrynus. Southeast Asian Pedostibes on the other hand, are nested within a Southeast Asian clade, which is the sister lineage to the Southeast Asian river toad genus Phrynoidis. We demonstrate that Indian and Southeast Asian Pedostibes are not only allopatric and polyphyletic, but also exhibit significant differences in morphology and reproductive mode, indicating that the Southeast Asian species' are not congeneric with the true Pedostibes of India. As a taxonomic solution, we describe a new genus, Rentapia gen. nov. to accommodate the Southeast Asian species.

  19. How fast do amphibians disperse? Introductions, distribution and dispersal of the common frog Rana temporaria and the common toad Bufo bufo on a coastal island in Central Norway

    Directory of Open Access Journals (Sweden)

    Dag Dolmen

    2016-04-01

    Full Text Available The common frog (Rana temporaria and the common toad (Bufo bufo were introduced successfully to the coastal island of Frøya in Central Norway several times during 1960–2012. There is still a very high degree of conformity between sites where they were introduced and the present distribution of the two species. However, in western Frøya, a release of frogs about 1996 was followed by a quick expansion of their distribution area; in 2012 and 2013, breeding was registered close to 7 km westwards and eastwards, respectively, i.e. a population dispersal speed of approximately 0.4 km/yr. On eastern Frøya and some small islands in the archipelago, area expansions at another four frog localities have been prevented by ecological barriers like unfavourable limnetic or terrestrial habitats or salty water. Two local common toad populations on eastern Frøya do not show any expansion either. However, an apparently isolated record of the species on western Frøya in 2011 can possibly be explained by the expansion westwards of a population in northern central Frøya, where toads were introduced around 1995. This stretch is about 9.9 km, i.e. an average population dispersal speed of 0.6 km/yr.

  20. Effects of seasonal variation on oxidative stress physiology in natural population of toad Bufo melanostictus; clues for analysis of environmental pollution.

    Science.gov (United States)

    Samanta, Luna; Paital, Biswaranjan

    2016-11-01

    Natural population of Bufo melanostictus in response to environmental cues shows several physiologic changes such as reproductive activity, hibernation, aestivation and metabolic depression in different seasons. We investigated the effects of seasonal fluctuations on oxidative stress (OS) physiology biomarkers, such as endogenous (ELPx) and induced (ILPx) lipid peroxidation, front-line redox regulatory enzymes (superoxide dismutase: SOD and catalase) and two non-enzyme antioxidant metabolites (ascorbic acid and reduced glutathione) in liver, gonad and cerebral hemisphere of toads collected from the Bhubaneswar area of India, where temperature fluctuates considerably rising to the highest in summer (∼46 °C) and being lowest in winter (<10 °C). Soil and air of the sampling site, although varying seasonally, were mostly found to be unpolluted, except for suspended particulate matter and respiratory particulate matter that were above recommended value. The magnitude of both ELPx and ILPx levels in most of the tissues, for example, ELPx in liver, cerebral hemisphere and ovary, and ILPx in liver of males and ovary, were found to be higher in rainy season in comparison to the other seasons. Nevertheless, levels of both ELPx and ILPx were low in testes in rainy season in comparison to the other two seasons. No correlation was observed between temperature and the studied OS parameters except a positive correlation with SOD and negative correlations with non-enzymatic small redox regulatory molecules in some selected tissues. Conversely, discriminant function analysis reveals a clear impact of the changing season on OS physiology of the toad. It implies that season considerably modulates OS physiology which be a reflection of the toads to abiotic pollutants alone and/or as results of metabolic changes under hibernation, aestivation and due to reproductive activities. Therefore, seasonal changes in OS physiological responses in poikilothermic models especially in toads

  1. 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)

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

    1995-01-01

    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.

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

    Science.gov (United States)

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

    2016-04-01

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

  3. DC electrical stimulation of the pretectal thalamus and its effects on the feeding behavior of the toad (Bufo bufo).

    Science.gov (United States)

    McConville, James; Laming, Peter R

    2007-06-01

    The feeding motivation of the common European common toad (Bufo bufo) can be quantified by the feeding sequence of arousal-orientation-approach-fixate-snap. Previous work has found that the optic tectum is an important structure responsible for the mediation of feeding behaviors, and combined electrical and visual stimulation of the optic tectum was found to increase the animals feeding behaviors. However, the pretectal thalamus has an inhibitory influence upon the optic tectum and its lesion results in disinhibited feeding behaviors. This suggests that feeding behavior of anurans is also subject to influence from the pretectal thalamus. Previous studies involving the application of DC stimulation to brain tissue has generated slow potential shifts and these shifts have been implicated in the modulation of the neural mechanisms associated with behavior. The current study investigated the application of DC stimulation to the diencephalon surface dorsal to the lateral posterodorsal pretectal thalamic nucleus in Bufo bufo, in order to assess effects on feeding motivation. The application of DC stimulation increased the incidence of avoidance behaviors to a visual prey stimulus while reducing the prey catching behavior component of approach, suggesting that the DC current applied to the pretectum increased the inhibition upon the feeding elements of the optic tectum. This can be explained by the generation of slow potential shifts.

  4. High genetic diversity of common toad (Bufo bufo) populations under strong natural fragmentation on a Northern archipelago.

    Science.gov (United States)

    Roth, Steffen; Jehle, Robert

    2016-03-01

    The last decades have shown a surge in studies focusing on the interplay between fragmented habitats, genetic variation, and conservation. In the present study, we consider the case of a temperate pond-breeding anuran (the common toad Bufo bufo) inhabiting a naturally strongly fragmented habitat at the Northern fringe of the species' range: islands offshore the Norwegian coast. A total of 475 individuals from 19 populations (three mainland populations and 16 populations on seven adjacent islands) were genetically characterized using nine microsatellite markers. As expected for a highly fragmented habitat, genetic distances between populations were high (pairwise F st values ranging between 0.06 and 0.33), with however little differences between populations separated by ocean and populations separated by terrestrial habitat (mainland and on islands). Despite a distinct cline in genetic variation from mainland populations to peripheral islands, the study populations were characterized by overall high genetic variation, in line with effective population sizes derived from single-sample estimators which were on average about 20 individuals. Taken together, our results reinforce the notion that spatial and temporal scales of fragmentation need to be considered when studying the interplay between landscape fragmentation and genetic erosion.

  5. Liver histopathology in the cane toad, Rhinella marina (Amphibia: Bufonidae), induced by Ortleppascaris sp. larvae (Nematoda: Ascarididae).

    Science.gov (United States)

    Silva, Jefferson P E; da Silva, Djane C B; Melo, Francisco T V; Giese, Elane G; Furtado, Adriano P; Santos, Jeannie N

    2013-04-01

    Exposure to parasites is considered to be an important factor in the development of many diseases and histopathologies which are the result of the parasite-host interaction. The present study evaluated the impact of natural infection by larvae of Ortleppascaris sp. (Nematoda: Ascaridida) in the liver of the cane toad Rhinella marina (Linnaeus, 1758). Larvae were encysted in nodules delimited by collagenous fibers and fibroblasts or freely within the hepatic parenchyma, provoking a clear response from the host. The histological examination of the liver revealed viable larvae in a number of different developmental stages, as well as cysts filled with amorphous material and cell residues and surrounded by dense fibrotic tissue. The infection of the liver by these larvae induces a significant increase in the area occupied by melanomacrophages and a reduction or deficit in the vascularization of the liver, hypertrophy of the hepatocytes, vacuolar bodies, and cytoplasmatic granules. Focal concentrations of inflammatory infiltrates were observed enclosing the unencapsulated early-stage larvae. These results indicate that infection by Ortleppascaris sp. induces severe physiological problems and histopathological lesions in the liver of R. marina .

  6. Systematics of the endangered toad genus Andinophryne (Anura: Bufonidae): phylogenetic position and synonymy under the genus Rhaebo.

    Science.gov (United States)

    Ron, Santiago R; Mueses-Cisneros, Jonh Jairo; Gutiérrez-Cárdenas, Paul David Alfonso; Rojas-Rivera, Alejandra; Lynch, Ryan L; Rocha, Carlos F Duarte; Galarza, Gabriela

    2015-04-16

    Bufonidae is one of the most diverse amphibian families. Its large-scale phylogenetic relationships are relatively well understood with the exception of few Neotropical genera that may have diverged early in the evolution of the family. One of those genera is Andinophryne, a poorly known group of three toad species distributed in the western slopes of the Andes of northern Ecuador and southern Colombia. Their phylogenetic position is unknown due to lack of genetic data. We estimated a new phylogeny (over 200 species) of the family Bufonidae based on DNA sequences of mitochondrial and nuclear genes to assess the phylogenetic position of Andinophryne based on recently collected specimens of A. colomai and A. olallai from Ecuador and Colombia. We also examined external and internal morphology of Andinophryne to explore its congruence with the new phylogeny. The mtDNA and nuclear phylogenies show that Andinophryne is embedded within Rhaebo, a genus that belongs to a large clade characterized by the presence parotoid glands. Morphological characters confirmed the affinity of Andinophryne to Rhaebo and a close relationship between Andinophryne colomai and Andinophryne olallai. Rhaebo was paraphyletic relative to Andinophryne and to solve this problem we synonymize Andinophryne under Rhaebo. We discuss putative morphological synapomorphies for Rhaebo including Andinophryne. We provide species accounts for R. atelopoides new comb., R. colomai new comb. and R. olallai new comb. including assessments of their conservation status. We suggest that the three species are Critically Endangered. Their altitudinal distribution and association with streams are characteristic of endangered Andean amphibians.

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

    Directory of Open Access Journals (Sweden)

    Rodrigo B. Ferreira

    2009-12-01

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

  8. Effect of toad skin extracts on the pain behavior of cancer model mice and its peripheral mechanism of action.

    Science.gov (United States)

    Chen, Tao; Yuan, Shen-Jun; Yu, Xue-Qin; Jiao, Liang-Bo; Hu, Wei; Chen, Wang-Long; Xie, Bo

    2017-01-01

    The changes in thermal and mechanical hyperalgesia in paw cancer pain model mice and the action mechanism of toad skin extracts (TSE) was investigated. Eighty female mice were subcutaneously injected with saline or inoculated with H22 hepatoma cells in the right hind paw and administration with saline, vehicle, morphine and TSE. The pain behavior was recorded before treatment and at 0.5, 1.0, 1.5, 3 and 6h after initial administration, and thereafter on the 2nd, 4th, 6th, and 8th day after administration. On the last day, samples were collected after the euthanasia for the detection of β-END, CRF, IL-1β, POMC, μ-OR, CD3+, CD8+ and CD4+ in sera and the tumor tissues. The results showed that TSE significantly increased the thresholds of thermal pain and mechanical pain, and upregulated the expressions of β-END, CRF, POMC, CD3+, CD8+ and μ-OR, and downregulated the expression of CD4+. These results indicate that TSE significantly relieved pain in cancer pain model mice and raised their pain threshold. In addition, TSE seems to play a prominent role in promoting the activity of tumor infiltrating lymphocytes (TILs, CD3+ and CD8+ T cells), and this immune-cell-derived peripheral analgesic pathway might have widespread potential for clinical use. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Leptin Manipulation Reduces Appetite and Causes a Switch in Mating Preference in the Plains Spadefoot Toad (Spea bombifrons.

    Directory of Open Access Journals (Sweden)

    Nicholas W Garcia

    Full Text Available Condition- or context-dependent mate choice occurs when females modify their mate preferences depending on their internal or external environment. While the ecological and evolutionary factors that favor the evolution of such plasticity are emerging, relatively little is known of the mechanisms underlying such choice. Here we evaluated whether leptin, a protein hormone involved in the regulation of appetite, might affect the expression of condition-dependent mate choice decisions. To do so, we administered leptin to spadefoot toads, Spea bombifrons, which exhibit condition-dependent mate choice for males of their own species versus congeneric males of S. multiplicata. In particular, poor-condition S. bombifrons are more likely than are good-condition S. bombifrons to prefer S. multiplicata males, but only in environments where hybridization between the two species is beneficial. We found that our leptin treatment reduced appetite in S. bombifrons adults, as was expected from leptin's known effects on appetite. However, although we predicted that leptin would reduce female preferences for heterospecific males, we found the opposite. In particular, our leptin treatment generated a consistent, repeatable preference for heterospecifics in an environment where females generally prefer conspecifics regardless of condition. These results indicate that leptin has the potential to affect female mate choice, but that it might do so in non-intuitive ways.

  10. No ecological opportunity signal on a continental scale? Diversification and life-history evolution of African true toads (Anura: Bufonidae).

    Science.gov (United States)

    Liedtke, H Christoph; Müller, Hendrik; Rödel, Mark-Oliver; Menegon, Michele; Gonwouo, LeGrand Nono; Barej, Michael F; Gvoždík, Václav; Schmitz, Andreas; Channing, Alan; Nagel, Peter; Loader, Simon P

    2016-08-01

    The niche-filling process predicted by the "ecological opportunity" (EO) model is an often-invoked mechanism for generating exceptional diversity in island colonizers. Whether the same process governs lineage accumulation and trait disparity during continental colonization events is less clear. Here, we test this prediction by investigating the rate dynamics and trait evolution of one of Africa's most widespread amphibian colonizers, the true toads (Bufonidae). By reconstructing the most complete molecular phylogeny of African Bufonidae to date, we find that the diversification of lineages in Africa best conforms to a constant rate model throughout time and across subclades, with little support for EO. Evolutionary rates of life-history traits have similarly been constant over time. However, an analysis of generalists and specialists showed a shift toward higher speciation rates associated with habitat specialization. The overall lack of EO signal can be interpreted in a number of ways and we propose several explanations. Firstly, methodological issues might preclude the detection of EO. Secondly, colonizers might not experience true EO conditions and due to the size, ecological heterogeneity and age of landmasses, the diversification processes might be more complex. Thirdly, lower speciation rates of habitat generalists may have affected overall proliferation of lineages. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  11. Evaluation in situ of genotoxicity and stress in South American common toad Rhinella arenarum in environments related to fluorite mine.

    Science.gov (United States)

    Pollo, Favio E; Grenat, Pablo R; Salinas, Zulma A; Otero, Manuel A; Salas, Nancy E; Martino, Adolfo L

    2017-08-01

    Little attention has been paid to the impact of wastewater generated by mining activities on fluoride. In this study, we evaluated the hematology responses of common South American toad Rhinella arenarum inhabiting natural and artificial environments associated with a fluorite mine from central Argentina. We analyzed three sampling stations associated with the fluorite mine: (I) Los Cerros Negros stream (CN), which runs on granitic rock with a high fluorite content; (II) Los Vallecitos stream (LV), which runs on metamorphic rock with low fluorite content; and (III) artificial decantation ponds (DP) containing sediments produced by fluorite flotation process. We calculated frequencies of micronuclei, erythrocyte nuclear abnormalities, mitosis, and immature erythrocytes. In addition, we performed a differential leukocyte count and determined neutrophils/lymphocyte ratio as a stress response estimator. We found high micronucleus (MN) and erythrocyte nuclear abnormality (ENA) frequencies in DP and CN but low frequencies in LV. The neutrophil/lymphocyte ratio was different among sites, with a significant increase in individuals from DP. Values registered in DP could be caused by exposure to mixture of compounds registered in dams that hold wastewater, while high values registered in CN stream might be due to natural concentrations of fluoride. Our results suggest that blood is an effective and non-destructive sensitive indicator for monitoring genotoxic agents in freshwater ecosystems.

  12. Population Structure, Historical Biogeography and Demographic History of the Alpine Toad Scutiger ningshanensis in the Tsinling Mountains of Central China

    Science.gov (United States)

    Meng, Hongzhe; Li, Xiaochen; Qiao, Penghai

    2014-01-01

    Population genetic structure, historical biogeography and historical demography of the alpine toad Scutiger ningshanensis were studied using the combined data mtDNA cytochrome b (cyt b) and the mtDNA cytochrome c oxidase subunit I (COI) as the molecular markers. This species has high genetic variation. There was a significant genetic differentiation among most populations. Three lineages were detected. The phylogenetic relationship analyses and the SAMOVA (spatial analysis of molecular variance) results showed significant phylogeographic structure. 82.15% genetic variation occurred among populations whereas differentiation within populations only contributed 17.85% to the total. Mantel test results showed a significant correlation between the pairwise calculated genetic distance and pairwise calculated geographical distance of the populations (regression coefficient  = 0.001286, correlation coefficient  = 0.77051, p (rrand≥robs)  = 0.0185climatic changes and repetitive population expansion/contraction together led to the high level of genetic variation in S. ningshanensis. A total of three management units (MUs) was determined, which must be considered when conservation policy is made in the future. PMID:24956389

  13. Irreversible modification of sodium channel inactivation in toad myelinated nerve fibres by the oxidant chloramine-T.

    Science.gov (United States)

    Wang, G K

    1984-01-01

    The effects of externally applied chloramine-T on the excitability of single toad myelinated nerve fibres were studied. Chloramine-T is a mild oxidant which reacts specifically with the cysteine and methionine residues of proteins. Chloramine-T prolongs the action potential of a single myelinated fibre by more than 1000-fold. This effect is concentration- and time-dependent; higher concentrations and longer incubation times increase prolongation. Under voltage-clamp conditions, sodium channel inactivation is markedly inhibited by chloramine-T while sodium channel activation remains normal. Prolonged depolarization of the membrane leads to a maintained sodium current. The maintained sodium currents show activation kinetics, dependence on membrane potential, and reversal potentials which are similar to those of normal, inactivating sodium currents in untreated fibres. Both the maintained and the peak sodium currents are equally inhibited by tetrodotoxin. After partial removal of sodium inactivation by brief exposures to chloramine-T, the voltage dependence of the steady-state sodium current inactivation (h infinity) is shifted in the depolarized direction by about 20 mV, even after correction for the non-inactivating component contributed by the maintained current. The phenomena described here imply that cysteine or methionine residues are critical for the sodium channel inactivation processes. The two different modifications of inactivation, its removal shown by the maintained current, and the shift in the voltage-dependence of the remaining inactivatable channels, reveal that at least two separate residues are modified by chloramine-T. PMID:6321714

  14. A Single Transcriptome of a Green Toad (Bufo viridis) Yields Candidate Genes for Sex Determination and -Differentiation and Non-Anonymous Population Genetic Markers

    Science.gov (United States)

    Gerchen, Jörn F.; Reichert, Samuel J.; Röhr, Johannes T.; Dieterich, Christoph; Kloas, Werner

    2016-01-01

    Large genome size, including immense repetitive and non-coding fractions, still present challenges for capacity, bioinformatics and thus affordability of whole genome sequencing in most amphibians. Here, we test the performance of a single transcriptome to understand whether it can provide a cost-efficient resource for species with large unknown genomes. Using RNA from six different tissues from a single Palearctic green toad (Bufo viridis) specimen and Hiseq2000, we obtained 22,5 Mio reads and publish >100,000 unigene sequences. To evaluate efficacy and quality, we first use this data to identify green toad specific candidate genes, known from other vertebrates for their role in sex determination and differentiation. Of a list of 37 genes, the transcriptome yielded 32 (87%), many of which providing the first such data for this non-model anuran species. However, for many of these genes, only fragments could be retrieved. In order to allow also applications to population genetics, we further used the transcriptome for the targeted development of 21 non-anonymous microsatellites and tested them in genetic families and backcrosses. Eleven markers were specifically developed to be located on the B. viridis sex chromosomes; for eight markers we can indeed demonstrate sex-specific transmission in genetic families. Depending on phylogenetic distance, several markers, which are sex-linked in green toads, show high cross-amplification success across the anuran phylogeny, involving nine systematic anuran families. Our data support the view that single transcriptome sequencing (based on multiple tissues) provides a reliable genomic resource and cost-efficient method for non-model amphibian species with large genome size and, despite limitations, should be considered as long as genome sequencing remains unaffordable for most species. PMID:27232626

  15. The effects of fasting and cold exposure on metabolic rate and mitochondrial proton leak in liver and skeletal muscle of an amphibian, the cane toad Bufo marinus.

    Science.gov (United States)

    Trzcionka, M; Withers, K W; Klingenspor, M; Jastroch, M

    2008-06-01

    Futile cycling of protons across the mitochondrial inner membrane contributes significantly to standard metabolic rate in a variety of ectothermic and endothermic animals, but adaptations of the mitochondrial bioenergetics to different environmental conditions have rarely been studied in ectotherms. Changes in ambient temperature and nutritional status have a great effect on the physiological demands of ectothermic amphibians and may require the adjustment of mitochondrial efficiency. In order to investigate the effect of temperature and nutritional status on the mitochondrial level, we exposed male cane toads to either 10 degrees C or 30 degrees C and fasted half of the animals in each group. Cold exposure resulted in a fourfold reduction of the resting metabolic rate whereas nutritional status had only minor effects. The mitochondrial adjustments to each condition were observed by comparing the proton leak kinetics of isolated liver and skeletal muscle mitochondria at 25 degrees C. In response to cold exposure, liver mitochondria showed a decrease in proton conductance while skeletal muscle mitochondria were unchanged. Additional food deprivation had minor effects in skeletal muscle, but in liver we uncovered surprising differences in energy saving mechanisms between the acclimation temperatures: in warm-acclimated toads, fasting resulted in a decrease of the proton conductance whereas in cold-acclimated toads, the activity of the respiratory chain was reduced. To investigate the molecular mechanism underlying mitochondrial proton leakage, we determined the adenine-nucleotide transporter (ANT) content, which explained tissue-specific differences in the basal proton leak, but neither the ANT nor uncoupling protein (UCP) gene expression correlated with alterations of the proton leak in response to physiological stimuli.

  16. Wild Cane Toads (Rhinella marina) Expel Foreign Matter from the Coelom via the Urinary Bladder in Response to Internal Injury, Endoparasites and Disease

    OpenAIRE

    Crystal Kelehear; Hugh I. Jones; Wood, Benjamin A.; Richard Shine

    2015-01-01

    Dissections of >1,200 wild-caught cane toads (Rhinella marina) in tropical Australia confirm a laboratory report that anurans can expel foreign objects from the coelom by incorporating them into the urinary bladder. The foreign objects that we found inside bladders included a diverse array of items (e.g., grass seeds, twigs, insect prey, parasites), many of which may have entered the coelom via rupture of the gut wall. In some cases, the urinary bladder was fused to other organs including liv...

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

    DEFF Research Database (Denmark)

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

    2004-01-01

    It is not clear how and whether terrestrial amphibians handle NaCl transport in the distal nephron. Therefore, we studied ion transport in isolated perfused collecting tubules and ducts from toad, Bufo bufo, by means of microelectrodes. No qualitative difference in basolateral cell membrane...... and amiloride application showed a small apical Na+ conductance. Arginine vasotocin depolarized Vbl. The small apical Na+ conductance indicates that the collecting duct system contributes little to NaCl reabsorption when compared to aquatic amphibians. In contrast, Vbl rapidly depolarized upon lowering of [Na...

  18. Thallium in spawn, juveniles, and adult common toads (Bufo bufo) living in the vicinity of a zinc-mining complex, Poland

    OpenAIRE

    Dmowski, Krzysztof; Rossa, Monika; Kowalska, Joanna; Krasnodębska-Ostręga, Beata

    2014-01-01

    A breeding population of the common toad Bufo bufo living in the vicinity of a Zn-Pb smelting works in Bukowno, Poland was studied for the presence of thallium. Tl concentration was measured in the bottom sediments of the spawning pond, in the laid eggs, in juveniles after metamorphosis, and in the selected tissues of the adult individuals. A very high concentration of Tl was detected in the spawn (13.97 ± 8.90 mg/kg d.w.). In 50 % of the spawn samples, levels exceeded 20 mgTl/kg d.w. The iss...

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

    Science.gov (United States)

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

    2012-01-01

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

  20. Common toad Rhinella arenarum (Hensel, 1867) and its importance in assessing environmental health: test of micronuclei and nuclear abnormalities in erythrocytes.

    Science.gov (United States)

    Pollo, Favio E; Bionda, Clarisa L; Salinas, Zulma A; Salas, Nancy E; Martino, Adolfo L

    2015-09-01

    Anthropogenic activities may generate significant changes in the integrity of aquatic ecosystems, so long-term monitoring of populations that inhabit them is crucial. Counting micronucleated erythrocytes (MN) and erythrocytic nuclear abnormalities (ENA) in peripheral blood is a widely used method for detecting chromosomal damage due to chemical agents in the water. We analyzed MN and ENA frequency in blood obtained from the common toad Rhinella arenarum populations in sites with different degrees of environmental degradation. The results of this study indicate that there is an association between the frequency of micronuclei and nuclear abnormalities and the degree of environmental alteration recorded for the sites studied.

  1. Molecular effectors in the chronic exposure to arsenic as early and sensitive biomarkers in developing Rhinella arenarum toads

    Energy Technology Data Exchange (ETDEWEB)

    Mardirosian, Mariana Noelia; Ceschin, Danilo Guillermo; Lascano, Cecilia Inés; Venturino, Andrés, E-mail: a.venturino@conicet.gov.ar

    2017-05-15

    Highlights: • Arsenic early induces MAPK pathway in R. arenarum embryos and larvae. • The MAPKs MEK-ERK in turn upregulate the transcription factors c-FOS and c-JUN. • SOD, CAT and GST would be affected by ROS at synthesis and degradation level. • Low As levels inducing molecular biomarkers have high probabilities of exceedence. • Molecular biomarkers are most adequate to ascertain As impact in R. arenarum. - Abstract: Arsenic, a natural element of ecological relevance, is one of the most toxic elements present in various regions of the world. It can be found in natural water sources throughout Argentina in concentrations between 0.01 and 15 mg L{sup –1}. The Argentinean autochthonous toad Rhinella arenarum was selected to study the molecular mechanisms involved in the effects and response to the chronic As exposure along its embryonic and larval development. We evaluated the effects on MAPK signal transduction pathway and transcription factors c-FOS and c-JUN, and the regulation of the expression at protein levels of different antioxidant enzymes. Our results indicated that As is modulating the MAPK pathway, increasing MEK and ERK levels both in the nuclear and post-nuclear fraction along the embryonic development and mainly at the beginning of the larval stage. Through this pathway, As can upregulate transcription factors like c-FOS and c-JUN, impacting the antioxidant response of the exposed embryos and larvae through antioxidant enzymes and recycling of GSH. Arsenic triggered specifically the synthesis of antioxidant enzymes in exposed R. arenarum embryo and larvae. In particular, the expression levels of SOD, CAT and GST enzymes analyzed by Western blot showed a similar behavior to their enzymatic activities in our previous work. This fact suggests that not only the synthesis of these antioxidant enzymes but also their rapid degradation after inactivation would be regulated in response to ROS levels. Antioxidant enzymes may show dual responses of

  2. Expression pattern of glycoconjugates in the Bidderian and ovarian follicles of the Brazilian toad Bufo ictericus analyzed by lectin histochemistry

    Directory of Open Access Journals (Sweden)

    C. F. Farias

    Full Text Available The Bidder's organ and ovary of the Brazilian toad Bufo ictericus were studied by light microscopy, using hematoxylin-eosin (HE and periodic acid Schiff (PAS staining. The expression and distribution of carbohydrate moieties was analyzed by lectin histochemistry, using 8 lectins with different carbohydrate specificities: Ulex europaeus (UEA I, Lens culinaris (LCA, Erythrina cristagalli (ECA, Arachis hypogaea (PNA, Ricinus communis (RCA I, Aleuria aurantia (AAA, Triticum vulgaris (WGA, and Glycine maximum (SBA. The results showed that the Bidderian zona pellucida presented alpha-mannose, alpha-L-fucose, beta-D-galactose, N-acetyl-D-glucosamine, and alpha/beta-N-acetyl-galactosamine residues. The Bidderian follicular cells showed the presence of beta-D-galactose and N-acetyl-D-glucosamine. In the extracellular matrix, alpha-mannose and alpha/beta-N-acetyl-galactosamine residues were detected. The ovarian zona pellucida showed alpha-L-fucose, N-acetyl-D-glucosamine, alpha/beta-N-acetyl-galactosamine residues, and alpha-mannose and N-acetyl-D-glucosamine residues were detected in the follicular cells. Thus, the zona pellucida in both organs contains N-acetyl-D-glucosamine, and alpha/beta-N-acetyl-galactosamine residues. alpha-L-fucose residues were detected in the zona pellucida of both organs, using different lectins. Considering that beta-D-galactose residue was absent from ovary but present in the Bidder's organ, this sugar residue may play an important role in follicle development, blocking the Bidderian follicles and preventing further development of the Bidder's organ into a functional ovary.

  3. Age-dependent changes in sensitivity to a pesticide in tadpoles of the common toad (Bufo bufo).

    Science.gov (United States)

    Mikó, Zsanett; Ujszegi, János; Hettyey, Attila

    2017-06-01

    The worldwide en masse application of pesticides and the frequently reported malign effects on several non-target organisms underpin the importance of ecotoxicological research on these anthropogenic pollutants. Previous studies showed that sensitivity to herbicides can vary widely depending on additional stress factors, on the species and even on the population investigated. However, there is little information about how sensitivity changes during ontogeny, and how the duration of exposure is linked to the magnitude of malign effects, even though this knowledge would be important for the interpretation of toxicity test results and for formulating recommendations regarding the timing of pesticide application. We exposed tadpoles of the common toad (Bufo bufo) to three concentrations (0, 2 and 4mg a.e./L) of a glyphosate-based herbicide during the 1st, 2nd, 3rd, 4th, or 5th period of larval development or during the entire experiment, and measured survival, time until metamorphosis and body mass at metamorphosis to estimate fitness-consequences. Younger tadpoles were more sensitive to the herbicide in all measured traits than older ones, and this age-dependence was especially pronounced at the high herbicide concentration. Furthermore, tadpoles exposed to the herbicide during the entire experiment developed slower than tadpoles exposed only early on, but we did not observe a similar effect either on body mass or survival. The observed age-dependence of sensitivity to herbicides draws attention to the fact that results of toxicity tests obtained for one age-class are not necessarily generalizable across ontogeny. Also, the age of test animals has to be considered when planning ecotoxicological studies and interpreting their results. Finally, taking into account the temporal breeding habits of local amphibians when planning pesticide application would be highly favourable: if tadpoles would not get exposed to the herbicide during their most sensitive early development

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

    Science.gov (United States)

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

    2015-07-01

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

  5. Population structure, historical biogeography and demographic history of the alpine toad Scutiger ningshanensis in the Tsinling Mountains of Central China.

    Directory of Open Access Journals (Sweden)

    Hongzhe Meng

    Full Text Available Population genetic structure, historical biogeography and historical demography of the alpine toad Scutiger ningshanensis were studied using the combined data mtDNA cytochrome b (cyt b and the mtDNA cytochrome c oxidase subunit I (COI as the molecular markers. This species has high genetic variation. There was a significant genetic differentiation among most populations. Three lineages were detected. The phylogenetic relationship analyses and the SAMOVA (spatial analysis of molecular variance results showed significant phylogeographic structure. 82.15% genetic variation occurred among populations whereas differentiation within populations only contributed 17.85% to the total. Mantel test results showed a significant correlation between the pairwise calculated genetic distance and pairwise calculated geographical distance of the populations (regression coefficient  = 0.001286, correlation coefficient  = 0.77051, p (rrand≥robs  = 0.0185<0.05, indicating the existence of isolation-by-distance pattern of genetic divergence for cyt b + COI sequence, which suggests that the distribution of genetic variation is due to geographical separation rather than natural selection. The population expansion or contraction and genetic differentiation between populations or lineages could be explained by topography and the repetitive uplifts of the Tsinling Mountains and the climatic cycles during the late Pliocene and Pleistocene. S. ningshanensis experienced a rapid population expansion about 40,000 years before present. The current decline in population size was probably caused by anthropogenic disturbance. Current populations of S. ningshanensis are from different refugia though the location of these refugia could not be determined in our study. Topography, climatic changes and repetitive population expansion/contraction together led to the high level of genetic variation in S. ningshanensis. A total of three management units (MUs was determined

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

    Science.gov (United States)

    James, Stacy M.; Little, Edward E.; Semlitsch, Raymond D.

    2004-01-01

    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 μg/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.

  7. Concordant morphological and molecular clines in a contact zone of the Common and Spined toad (Bufo bufo and B. spinosus) in the northwest of France.

    Science.gov (United States)

    Arntzen, Jan W; Trujillo, Tania; Butôt, Roland; Vrieling, Klaas; Schaap, Onno; Gutiérrez-Rodríguez, Jorge; Martínez-Solano, Iñigo

    2016-01-01

    Hybrid zones are regions where individuals of two species meet and produce hybrid progeny, and are often regarded as natural laboratories to understand the process of species formation. Two microevolutionary processes can take place in hybrid zones, with opposing effects on population differentiation. Hybridization tends to produce genetic homogenization, reducing species differences, whereas the presence of mechanisms of reproductive isolation result in barriers to gene flow, maintaining or increasing differences between taxa. Here we study a contact zone between two hybridizing toad species, Bufo bufo and B. spinosus, through a combination of molecular (12 polymorphic microsatellites, four nuclear and two mitochondrial SNP markers) and morphological data in a transect in the northwest of France. The results show largely concordant clines across markers, defining a narrow hybrid zone of ca. 30 km wide. Most hybrids in the centre of the contact zone are classified as F2 or backcrossed individuals, with no individuals assigned to the F1 hybrid class. We discuss the implications of these results for our understanding of the evolutionary history of these species. We anticipate that the toad contact zone here described will become an important asset in the study of hybrid zone dynamics and evolutionary biology because of its easy access and the abundance of the species involved.

  8. Thallium in spawn, juveniles, and adult common toads (Bufo bufo) living in the vicinity of a zinc-mining complex, Poland.

    Science.gov (United States)

    Dmowski, Krzysztof; Rossa, Monika; Kowalska, Joanna; Krasnodębska-Ostręga, Beata

    2015-01-01

    A breeding population of the common toad Bufo bufo living in the vicinity of a Zn-Pb smelting works in Bukowno, Poland was studied for the presence of thallium. Tl concentration was measured in the bottom sediments of the spawning pond, in the laid eggs, in juveniles after metamorphosis, and in the selected tissues of the adult individuals. A very high concentration of Tl was detected in the spawn (13.97 ± 8.90 mg/kg d.w.). In 50% of the spawn samples, levels exceeded 20 mgTl/kg d.w. The issue of maternal transfer of thallium from females to oocytes is discussed. Due to a significant accumulation of thallium, spawn analysis can be used as a sensitive indicator of the presence of this element in the environment and may replace more invasive methods that involve the killing of adult animals. In those regions that are abundant in Zn-Pb ores, the spawn of amphibians may be a very important source of thallium contamination for predators. From among all tissues of the Bukowno adult toads, the livers have shown the highest accumulation of thallium (mean 3.98 mg/kg d.w. and maximum value--18.63). For as many as 96.5% of livers, concentrations exceeded 1.0 mgTl/kg d.w. which is treated as indicative of poisoning.

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

    Science.gov (United States)

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

    2014-10-01

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

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

    Science.gov (United States)

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

    2014-12-01

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

  11. Discovery of two bombinin peptides with antimicrobial and anticancer activities from the skin secretion of Oriental fire-bellied toad, Bombina orientalis.

    Science.gov (United States)

    Zhou, Chang; Wang, Zhengming; Peng, Xin; Liu, Yao; Lin, Yangjun; Zhang, Zhe; Qiu, Yuling; Jin, Meihua; Wang, Ran; Kong, Dexin

    2018-01-01

    Amphibian skin secretions are known to contain numerous peptides with a large array of biological activities. Bombinins are a group of amphibian-derived peptides with broad spectrum antimicrobial activities that have been only identified from the ancient toad species, Bombina. In this study, we described the identification and characterization of a novel bombinin precursor which encoded a bombinin-like peptide (BLP-7) and a novel bombinin H-type peptide (named as Bombinin H-BO) from the skin secretion of Oriental fire-bellied toad, Bombina orientalis. The primary structures of both mature peptides were determined by combinations of molecular cloning of peptide precursor-encoding cDNAs and mass spectrometry techniques. Secondary structure prediction revealed that both peptides had cationic amphipathic α-helical structural features. The synthetic replicate of BLP-7 displayed more potent antimicrobial activity than Bombinin H-BO against Gram-positive and Gram-negative bacteria and yeast. Also, in vitro antitumour assay showed that both peptides possessed obvious antiproliferative activity on three human hepatoma cells (Hep G2/SK-HEP-1/Huh7) at the non-toxic doses. These results indicate the peptide family of bombinins could be a potential source of drug candidates for anti-infection and anticancer therapy. © 2017 John Wiley & Sons A/S.

  12. Osmotic reversal induces assembly of tight junction strands at the basal pole of toad bladder epithelial cells but does not reverse cell polarity.

    Science.gov (United States)

    Chevalier, J; Pinto da Silva, P

    1987-01-01

    This paper reports the effect of reversing the osmotic environment between luminal and serosal compartments of a toad urinary bladder on the polarity of assembly of tight junction strands. Toad bladders were filled with Ringer's solution (220 mOsm) and were immersed in distilled water at room temperature or at 37 degrees C. Within two minutes, new tight junction strands are assembled. The new tight junctional strands unite the basal pole of epithelial cells with the apical side of basal cells. Physiological studies show that oxytocin, a synthetic analog of antidiuretic hormone, is still capable of inducing increases in water transport in epithelia which were osmotically reversed. This capacity decreases significantly for longer periods of osmotic reversal. Osmotic reversal does not alter the original polarity of epithelial cells: the apical tight junction belt, at the apical pole, is not displaced; the freeze-fracture morphology typical of apical plasma membrane (particle-rich E faces; particle-poor P faces) is not altered; oxytocin and cyclic AMP induce aggregates which are observed only at the apical plasma membrane. Massive assembly of junctional elements occurs even in epithelia preincubated in the presence of cycloheximide (an inhibitor of protein synthesis) or of cytoskeleton perturbers. Our experiments show that the polarity of assembly of tight junction strands depends on the vectorial orientation of the osmotic environment of the epithelium.

  13. Mixed population genomics support for the central marginal hypothesis across the invasive range of the cane toad (Rhinella marina) in Australia.

    Science.gov (United States)

    Trumbo, Daryl R; Epstein, Brendan; Hohenlohe, Paul A; Alford, Ross A; Schwarzkopf, Lin; Storfer, Andrew

    2016-09-01

    Understanding factors that cause species' geographic range limits is a major focus in ecology and evolution. The central marginal hypothesis (CMH) predicts that species cannot adapt to conditions beyond current geographic range edges because genetic diversity decreases from core to edge due to smaller, more isolated edge populations. We employed a population genomics framework using 24 235-33 112 SNP loci to test major predictions of the CMH in the ongoing invasion of the cane toad (Rhinella marina) in Australia. Cane toad tissue samples were collected along broad-scale, core-to-edge transects across their invasive range. Geographic and ecological core areas were identified using GIS and habitat suitability indices from ecological niche modelling. Bayesian clustering analyses revealed three genetic clusters, in the northwest invasion-front region, northeast precipitation-limited region and southeast cold temperature-limited region. Core-to-edge patterns of genetic diversity and differentiation were consistent with the CMH in the southeast, but were not supported in the northeast and showed mixed support in the northwest. Results suggest cold temperatures are a likely contributor to southeastern range limits, consistent with CMH predictions. In the northeast and northwest, ecological processes consisting of a steep physiological barrier and ongoing invasion dynamics, respectively, are more likely explanations for population genomic patterns than the CMH. © 2016 John Wiley & Sons Ltd.

  14. Development of Nuclear Microsatellite Loci and Mitochondrial Single Nucleotide Polymorphisms for the Natterjack Toad, Bufo (Epidalea) calamita (Bufonidae), Using Next Generation Sequencing and Competitive Allele Specific PCR (KASPar).

    Science.gov (United States)

    Faucher, Leslie; Godé, Cécile; Arnaud, Jean-François

    2016-01-01

    Amphibians are undergoing a major decline worldwide and the steady increase in the number of threatened species in this particular taxa highlights the need for conservation genetics studies using high-quality molecular markers. The natterjack toad, Bufo (Epidalea) calamita, is a vulnerable pioneering species confined to specialized habitats in Western Europe. To provide efficient and cost-effective genetic resources for conservation biologists, we developed and characterized 22 new nuclear microsatellite markers using next-generation sequencing. We also used sequence data acquired from Sanger sequencing to develop the first mitochondrial markers for KASPar assay genotyping. Genetic polymorphism was then analyzed for 95 toads sampled from 5 populations in France. For polymorphic microsatellite loci, number of alleles and expected heterozygosity ranged from 2 to 14 and from 0.035 to 0.720, respectively. No significant departures from panmixia were observed (mean multilocus F IS = -0.015) and population differentiation was substantial (mean multilocus F ST = 0.222, P < 0.001). From a set of 18 mitochondrial SNPs located in the 16S and D-loop region, we further developed a fast and cost-effective SNP genotyping method based on competitive allele-specific PCR amplification (KASPar). The combination of allelic states for these mitochondrial DNA SNP markers yielded 10 different haplotypes, ranging from 2 to 5 within populations. Populations were highly differentiated (G ST = 0.407, P < 0.001). These new genetic resources will facilitate future parentage, population genetics and phylogeographical studies and will be useful for both evolutionary and conservation concerns, especially for the set-up of management strategies and the definition of distinct evolutionary significant units. © The American Genetic Association 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

    Directory of Open Access Journals (Sweden)

    Mu Yang

    2011-01-01

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

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

    Science.gov (United States)

    Shaffer, H. Bradley; Fellers, Gary M.; Magee, Allison; Voss, S. Randal

    2000-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Sara Quagliata

    2008-12-01

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

  18. Geographic variation in life-history traits: growth season affects age structure, egg size and clutch size in Andrew's toad (Bufo andrewsi).

    Science.gov (United States)

    Liao, Wen Bo; Luo, Yi; Lou, Shang Ling; Lu, Di; Jehle, Robert

    2016-01-01

    Environmental variation associated with season length is likely to promote differentiation in life-history traits, but has been little studied in natural populations of ectotherms. We investigated patterns of variation in egg size, clutch size, age at sexual maturity, maximum age, mean age, growth rate and adult body size in relation to growth season length among 17 populations of Andrew's toad (Bufo andrewsi) at different latitudes and altitudes in the Hengduan Mountains, western China. We found that egg size, age at sexual maturity, and mean age increased with decreasing length of the growth season, whereas clutch size showed a converse cline. Body size did not increase with decreasing length of the growth season, but was tightly linked to lifetime activity (i.e. the estimated number of active days during lifetime). Males and females differed in their patterns of geographic variation in growth rates, which may be the result of forces shaping the trade-off between growth and reproduction in different environments. Our findings suggest that growth season plays an important role in shaping variation in life-history traits in B. andrewsi across geographical gradients.

  19. 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)

    Zeisset, Inga; Beebee, Trevor J. C.

    2014-01-01

    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

  20. When new human-modified habitats favour the expansion of an amphibian pioneer species: Evolutionary history of the natterjack toad (Bufo calamita) in a coal basin.

    Science.gov (United States)

    Faucher, Leslie; Hénocq, Laura; Vanappelghem, Cédric; Rondel, Stéphanie; Quevillart, Robin; Gallina, Sophie; Godé, Cécile; Jaquiéry, Julie; Arnaud, Jean-François

    2017-09-01

    Human activities affect microevolutionary dynamics by inducing environmental changes. In particular, land cover conversion and loss of native habitats decrease genetic diversity and jeopardize the adaptive ability of populations. Nonetheless, new anthropogenic habitats can also promote the successful establishment of emblematic pioneer species. We investigated this issue by examining the population genetic features and evolutionary history of the natterjack toad (Bufo [Epidalea] calamita) in northern France, where populations can be found in native coastal habitats and coalfield habitats shaped by European industrial history, along with an additional set of European populations located outside this focal area. We predicted contrasting patterns of genetic structure, with newly settled coalfield populations departing from migration-drift equilibrium. As expected, coalfield populations showed a mosaic of genetically divergent populations with short-range patterns of gene flow, and native coastal populations indicated an equilibrium state with an isolation-by-distance pattern suggestive of postglacial range expansion. However, coalfield populations exhibited (i) high levels of genetic diversity, (ii) no evidence of local inbreeding or reduced effective population size and (iii) multiple maternal mitochondrial lineages, a genetic footprint depicting independent colonization events. Furthermore, approximate Bayesian computations suggested several evolutionary trajectories from ancient isolation in glacial refugia during the Pleistocene, with biogeographical signatures of recent expansion probably confounded by human-mediated mixing of different lineages. From an evolutionary and conservation perspective, this study highlights the ecological value of industrial areas, provided that ongoing regional gene flow is ensured within the existing lineage boundaries. © 2017 John Wiley & Sons Ltd.

  1. Different morphologic formation patterns of dark patches in the black-spotted frog (Pelophylax nigromaculata) and the Asiatic toad (Bufo gargarizans).

    Science.gov (United States)

    Guangming, Gan; Tao, Zhao; Chao, Li; Moyan, Zhao

    2017-01-01

    The black-spotted frog (Pelophylax nigromaculata) and Asiatic toad (Bufo gargarizans), two relatively distantly related species, live in different habitats with different adaptive dark patches. To explain the formation of dark patches, the distribution patterns of melanin granules were examined with light microscopy and transmission electron microscopy. Melanin granules were produced and gathered into the "cap" structures on top of the nuclei in most epidermal cells. The "cap" structures may play a role in forming the dorsal dark patches coupled with three-layer melanophores, which can give rise to three layers of interconnected melanin networks in the dorsal dermis in P. nigromaculata. Epidermal melanocytes are rare and do not have a definitive role in forming dorsal dark patches in either P. nigromaculata or B. gargarizans. In B. gargarizans, the dermal melanophores only give rise to a single-layered melanin network, which hardly results in dark patches in the dorsal skin. However, the dermal melanophores migrate twice and form into pseudostratified networks, leading to dark patch formation in the ventral skin in B. gargarizans. The melanin granules precisely coregulate dark patches in the dermis and/or epidermis in P. nigromaculata and B. gargarizans. The dark patch formation depends on melanin granules in the epidermis or/and dermis in P. nigromaculata and B. gargarizans.

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

    Science.gov (United States)

    Reda, Enayat Salem Ahmed

    2010-11-01

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

  3. Phylogeography of a widespread terrestrial vertebrate in a barely-studied Palearctic region: green toads (Bufo viridis subgroup) indicate glacial refugia in Eastern Central Asia.

    Science.gov (United States)

    Zhang, Yi-Jun; Stöck, Matthias; Zhang, Peng; Wang, Xiu-Ling; Zhou, Hui; Qu, Liang-Hu

    2008-11-01

    The phylogeography of western Palearctic species is relatively well studied, but data on Eastern Central Asia are scarce. We present one of the first data sets from a widespread terrestrial vertebrate (Bufo pewzowi) inhabiting Eastern Central Asian mountains and deserts to gain knowledge on its phylogeography in this region. We applied combined phylogenetic and demographic analyses to understand the evolutionary history using mitochondrial DNA D-loop variation of toads from 37 locations. Genetic structure of Bufo pewzowi is strongly affected by landscape: we found three haplotype groups in eastern Kazakhstan, Dzungaria and Tarim Basin, divided by the Tian Shan and Dzungarian Alatau ranges. A vicariant hypothesis may explain divergence among groups. The divergence time of the three major clades was estimated about 0.9 million years ago (confidence interval 0.5-1.4), and is discussed with respect to Quaternary uplifting and glaciation in the Tian Shan. Demographic analyses provided evidence for both historical bottlenecks and population expansions and suggested Pleistocene signatures. Glacial refugia were inferred in the Tarim Basin (around the Turpan depression), in southern Dzungaria (Urumqui region), at the northern foot of the Tian Shan (Gongnaisi) and perhaps at the Altai range (Terekti). Regional Post-Last Glacial Maximum dispersal patterns are proposed. A taxonomic hypothesis is presented. This study provides a detailed history of how a widespread terrestrial vertebrate responded to geological change and Quaternary glacial events in Eastern Central Asia and may have significance for future phylogeographic research in this understudied region.

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

    Directory of Open Access Journals (Sweden)

    Sanuy, D.

    2008-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Inga Zeisset

    Full Text Available 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.

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

    Science.gov (United States)

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

    2016-04-01

    The Oriental fire-bellied toad (Bombina orientalis) is a commonly used study organism, but knowledge of its evolutionary history is incomplete. We analyze sequence data from four genetic markers (mtDNA genes encoding cytochrome c oxidase subunit I, cytochrome b, and 12S-16S rRNA; nuDNA gene encoding recombination activating gene 2) from 188 individuals across its range in Northeast Asia to elucidate phylogeographic patterns and to identify the historic events that shaped its evolutionary history. Although morphologically similar across its range, B. orientalis exhibits phylogeographic structure, which we infer was shaped by geologic, climatic, and anthropogenic events. Phylogenetic and divergence-dating analyses recover four genetically distinct groups of B. orientalis: Lineage 1-Shandong Province and Beijing (China); Lineage 2-Bukhan Mountain (Korea); Lineage 3-Russia, Northeast China, and northern South Korea; and Lineage 4-South Korea. Lineage 2 was previously unknown. Additionally, we discover an area of secondary contact on the Korean Peninsula, and infer a single dispersal event as the origin of the insular Jeju population. Skyline plots estimate different population histories for the four lineages: Lineages 1 and 2 experienced population decreases, Lineage 3 remained stable, while Lineage 4 experienced a sharp increase during the Holocene. The timing of the population expansion of Lineage 4 coincides with the advent of rice cultivation, which may have facilitated the increase in population size by providing additional breeding habitat. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Organization of the pallium in the fire-bellied toad Bombina orientalis. I: Morphology and axonal projection pattern of neurons revealed by intracellular biocytin labeling.

    Science.gov (United States)

    Roth, Gerhard; Laberge, Frédéric; Mühlenbrock-Lenter, Sabine; Grunwald, Wolfgang

    2007-03-20

    The cytoarchitecture and axonal projection pattern of pallial areas was studied in the fire-bellied toad Bombina orientalis by intracellular injection of biocytin into a total of 326 neurons forming 204 clusters. Five pallial regions were identified, differing in morphology and projection pattern of neurons. The rostral pallium receiving the bulk of dorsal thalamic afferents has reciprocal connections with all other pallial areas and projects to the septum, nucleus accumbens, and anterior dorsal striatum. The medial pallium projects bilaterally to the medial pallium, septum, nucleus accumbens, mediocentral amygdala, and hypothalamus and ipsilaterally to the rostral, dorsal, and lateral pallium. The ventral part of the medial pallium is distinguished by efferents to the eminentia thalami and the absence of contralateral projections. The dorsal pallium has only ipsilateral projections running to the rostral, medial, and lateral pallium; septum; nucleus accumbens; and eminentia thalami. The lateral pallium has ipsilateral projections to the olfactory bulbs and to the rostral, medial, dorsal, and ventral pallium. The ventral pallium including the striatopallial transition area (SPTA) has ipsilateral projections to the olfactory bulbs, rostral and lateral pallium, dorsal striatopallidum, vomeronasal amygdala, and hypothalamus. The medial pallium can be tentatively homologized with the mammalian hippocampal formation, the dorsal pallium with allocortical areas, the lateral pallium rostrally with the piriform and caudally with the entorhinal cortex, the ventral pallium with the accessory olfactory amygdala. The rostral pallium, with its projections to the dorsal and ventral striatopallidum, resembles the mammalian frontal cortex. 2007 Wiley-Liss, Inc.

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

    DEFF Research Database (Denmark)

    Budtz, Poul Egede; Christoffersen, Betina C.; Johansen, Jesper S.

    1995-01-01

    studied in toads (Bufo bufo) immediately before, and after 2,7, and 14 days exposure to distilled water. General epidermal structure was not affected. However, the numbers of MRCs per mm2 (DMRC) increased throughout the experiment as revealed by staining of epidermal sheets with AgNO3 (Ag) or methylene...... blue (MB). Part of the increased DMRC was accounted for by an increase in MRC subpopulation(s) that stained neither with Ag nor MB. The cell birth rate (Kb) decreased and cell loss by moulting (Kd) increased without any significant change in epidermal cell pool size, indicating a reduced apoptotic rate...

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

    Science.gov (United States)

    2010-01-01

    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. PMID

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

    Science.gov (United States)

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

    2014-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    Maria Mastrodonato

    2011-07-01

    Full Text Available We studied the glycopatterns and ultrastructure of the extra-cellular matrix (ECM of the egg of the Apennine yellow-bellied toad Bombina pachypus, by light and electron microscopy in order to determine structure, chemical composition and function. Histochemical techniques in light microscopy included PAS and Alcian Blue pH 2.5 and 1.0, performed also after b-elimination. Lectin-binding was tested with nine lectins (AAA, ConA, DBA, HPA, LTA, PNA, SBA, UEA-I, WGA. An inner fertilization envelope (FE and five jelly layers (J1–J5 were observed, differing in histochemical staining, lectin binding and ultrastructure. Most glycans were O-linked, with many glucosamylated and fucosylated residues. The fertilization envelope presented a perivitelline space and a fertilization layer, with mostly neutral glycans. The jelly layers consisted of fibers and granules, whose number and orientation differed between layers. Fibers were densely packed in J1 and J4 layers, whereas a looser arrangement was observed in the other layers. Jelly-layer glycans were mostly acidic and particularly abundant in the J1 and J4 layers. In the J1, J2 and J5 layers, neutral, N-linked glycans were also observed. Mannosylated and/or glucosylated as well as galactosyl/galactosaminylated residues were more abundant in the outer layers. Many microorganisms were observed in the J5 layer. We believe that, apart from their functions in the fertilization process, acidic and fucosylated glycans could act as a barrier against pathogen penetration. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 2, pp. 306–316

  12. Phylogeographic and population insights of the Asian common toad (Bufo gargarizans in Korea and China: population isolation and expansions as response to the ice ages

    Directory of Open Access Journals (Sweden)

    Amaël Borzée

    2017-11-01

    Full Text Available The effects of ice ages on speciation have been well documented for many European and North American taxa. In contrast, very few studies have addressed the consequences of such environmental and topographical changes in North East Asian species. More precisely, the Korean Peninsula offers a unique model to assess patterns and processes of speciation as it hosts the northern- and eastern-most distribution limit of some widespread Asian taxa. Despite this, studies addressing phylogeographic patterns and population genetics in the peninsula and surrounding countries are few and studies for most families are lacking. Here we inferred the phylogenetic relationships of the common toad (Bufo gargarizans from South Korea and their North East Asian counterpart populations, based on mitochondrial data. Korean B. gargarizans GenBank BLASTs matched few individuals from nearby China, but the presence of a Korean clade suggests isolation on the Korean Peninsula, previous to the last glacial maximum, linked to sea level resurgence. Molecular clock calibrations within this group were used to date the divergence between clades and their relationship to paleo-climatic events in the area. Lack of genetic structure among South Korean populations and strong homogeneity between the Korean and some Chinese localities suggest weak isolation and recent expansion. Geographical projection of continuous coalescent maximum-clade-credibility trees shows an original Chinese expansion towards the Korean Peninsula through the Yellow Sea circa two million years ago with colonisation events dating circa 800 thousand years ago (K. y. a.. Following this colonisation, the data point to outgoing Korean Peninsula dispersal events throughout different periods, towards the North through land, and West through land bridge formations over the Yellow Sea during sea level falls. In accordance, demographic analyses revealed a population expansion in the Koran Peninsula circa 300 K. y. a

  13. Phylogeographic and population insights of the Asian common toad (Bufo gargarizans) in Korea and China: population isolation and expansions as response to the ice ages.

    Science.gov (United States)

    Borzée, Amaël; Santos, Joana L; Sánchez-RamÍrez, Santiago; Bae, Yoonhyuk; Heo, Kyongman; Jang, Yikweon; Jowers, Michael Joseph

    2017-01-01

    The effects of ice ages on speciation have been well documented for many European and North American taxa. In contrast, very few studies have addressed the consequences of such environmental and topographical changes in North East Asian species. More precisely, the Korean Peninsula offers a unique model to assess patterns and processes of speciation as it hosts the northern- and eastern-most distribution limit of some widespread Asian taxa. Despite this, studies addressing phylogeographic patterns and population genetics in the peninsula and surrounding countries are few and studies for most families are lacking. Here we inferred the phylogenetic relationships of the common toad ( Bufo gargarizans ) from South Korea and their North East Asian counterpart populations, based on mitochondrial data. Korean B. gargarizans GenBank BLASTs matched few individuals from nearby China, but the presence of a Korean clade suggests isolation on the Korean Peninsula, previous to the last glacial maximum, linked to sea level resurgence. Molecular clock calibrations within this group were used to date the divergence between clades and their relationship to paleo-climatic events in the area. Lack of genetic structure among South Korean populations and strong homogeneity between the Korean and some Chinese localities suggest weak isolation and recent expansion. Geographical projection of continuous coalescent maximum-clade-credibility trees shows an original Chinese expansion towards the Korean Peninsula through the Yellow Sea circa two million years ago with colonisation events dating circa 800 thousand years ago (K. y. a.). Following this colonisation, the data point to outgoing Korean Peninsula dispersal events throughout different periods, towards the North through land, and West through land bridge formations over the Yellow Sea during sea level falls. In accordance, demographic analyses revealed a population expansion in the Koran Peninsula circa 300 K. y. a., likely attributed

  14. Multilocus phylogeography of the common midwife toad, Alytes obstetricans (Anura, Alytidae): Contrasting patterns of lineage diversification and genetic structure in the Iberian refugium.

    Science.gov (United States)

    Gonçalves, H; Maia-Carvalho, B; Sousa-Neves, T; García-París, M; Sequeira, F; Ferrand, N; Martínez-Solano, I

    2015-12-01

    Recent investigations on the evolutionary history of the common midwife toad (Alytes obstetricans) revealed high levels of geographically structured genetic diversity but also a situation where delineation of major historical lineages and resolution of their relationships are much more complex than previously thought. We studied sequence variation in one mitochondrial and four nuclear genes throughout the entire distribution range of all recognized A. obstetricans subspecies to infer the evolutionary processes that shaped current patterns of genetic diversity and population subdivision. We found six divergent, geographically structured mtDNA haplogroups diagnosing population lineages, and varying levels of admixture in nuclear markers. Given the timeframe inferred for the splits between major lineages, the climatic and environmental changes that occurred during the Pleistocene seem to have shaped the diversification history of A. obstetricans. Survival of populations in allopatric refugia through the Ice Ages supports the generality of the "refugia-within-refugia" scenario for the Iberian Peninsula. However, lineages corresponding to subspecies A. o. almogavarii, A. o. pertinax, A. o. obstetricans, and A. o. boscai responded differently to Pleistocene climatic oscillations after diverging from a common ancestor. Alytes o. obstetricans expanded northward from a northern Iberian refugium through the western Pyrenees, leaving a signal of contrasting patterns of genetic diversity, with a single mtDNA haplotype north of the Pyrenees from SW France to Germany. Both A. o. pertinax and A. o. boscai are widespread and genetically diverse in Iberia, the latter comprising two divergent lineages with a long independent history. Finally, A. o. almogavarii is mostly restricted to the north-eastern corner of Iberia north of the Ebro river, with additional populations in a small region in south-eastern France. This taxon exhibits unparalleled levels of genetic diversity and little

  15. Rapid range expansion in the Great Plains narrow-mouthed toad (Gastrophryne olivacea) and a revised taxonomy for North American microhylids.

    Science.gov (United States)

    Streicher, Jeffrey W; Cox, Christian L; Campbell, Jonathan A; Smith, Eric N; de Sá, Rafael O

    2012-09-01

    We investigated genetic variation within the Great Plains narrow-mouthed toad, Gastrophryne olivacea, across its geographic range in the United States and Mexico. An analysis of mitochondrial DNA (mtDNA) from 105 frogs revealed remarkably low levels of genetic diversity in individuals inhabiting the central United States and northern Mexico. We found that this widespread matrilineal lineage is divergent (ca. 2% in mtDNA) from haplotypes that originate from the western United States and western coast of Mexico. Using a dataset that included all five species of Gastrophryne and both species of the closely related genus Hypopachus, we investigated the phylogenetic placement of G. olivacea. This analysis recovered strong support that G. olivacea, the tropically distributed G. elegans, and the temperately distributed G. carolinensis constitute a monophyletic assemblage. However, the placement of G. pictiventris and G. usta render Gastrophryne paraphyletic with respect to Hypopachus. To complement our mitochondrial analysis, we examined a small fragment of nuclear DNA and recovered consistent patterns. In light of our findings we recommend (1) the resurrection of the nomen G. mazatlanensisTaylor (1943) for the disjunct western clade of G. olivacea and (2) the tentative placement of G. pictiventris and G. usta in Hypopachus. To explore possible scenarios leading to low levels of genetic diversity in G. olivacea, we used mismatch distributions and Bayesian Skyline plots to examine historic population expansion and demography. Collectively these analyses suggest that G. olivacea rapidly expanded in effective population size and geographic range during the late Pleistocene or early Holocene. This hypothesis is consistent with fossil data from northern localities and contemporary observations that suggest ongoing northern expansion. Given our findings, we suspect that the rapid range expansion of G. olivacea may have been facilitated by ecological associations with open

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

    Science.gov (United States)

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

    2014-10-01

    The herbicide glyphosate and the insecticide cypermethrin are key pesticides of modern management in soy and corn cultures. Although these pesticides are likely to co-occur in ephemeral ponds or aquatic systems supporting amphibian wildlife, the toxicological interactions prevailing in mixtures of these two pesticides have been little studied. The current study evaluated the toxicity of equitoxic and non-equitoxic binary mixtures of glyphosate- and cypermethrin-based pesticides to tadpoles of the common South American toad, Rhinella arenarum. Two different combinations of commercial products were tested: glyphosate Glifosato Atanor®+cypermethrin Xiper® and glyphosate Glifoglex®+cypermethrin Glextrin®. When tested individually, the formulations presented the following 96 h-LC50s: Glifosato Atanor® 19.4 mg ae L(-1) and Glifoglex 72.8 mg ae L(-1), Xiper® 6.8 mg L(-1) and Glextrin® 30.2 mg L(-1). Equitoxic and non-equitoxic mixtures were significantly synergic in both combinations of commercial products tested. The magnitude of the synergy (factor by which toxicity differed from concentration addition) was constant at around twofold for all tested proportions of the glyphosate Glifoglex®+cypermethrin Glextrin® mixture; whereas the magnitude of the synergy varied between 4 and 9 times in the glyphosate Glifosato Atanor®+cypermethrin Xiper® mixture. These results call for more research to be promptly undertaken in order to understand the mechanisms behind the synergy observed and to identify and quantify the extent of its environmental impacts. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Morphology and axonal projection pattern of neurons in the telencephalon of the fire-bellied toad Bombina orientalis: an anterograde, retrograde, and intracellular biocytin labeling study.

    Science.gov (United States)

    Roth, Gerhard; Mühlenbrock-Lenter, Sabine; Grunwald, Wolfgang; Laberge, Frédéric

    2004-10-04

    The connectivity and cytoarchitecture of telencephalic centers except dorsal and medial pallium were studied in the fire-bellied toad Bombina orientalis by anterograde and retrograde biocytin labeling and intracellular biocytin injection (total of 148 intracellularly labeled neurons or neuron clusters). Our findings suggest the following telencephalic divisions: (1) a central amygdala-bed nucleus of the stria terminalis in the caudal midventral telencephalon, connected to visceral-autonomic centers; (2) a vomeronasal amygdala in the caudolateral ventral telencephalon receiving input from the accessory olfactory bulb and projecting mainly to the preoptic region/hypothalamus; (3) an olfactory amygdala in the caudal pole of the telencephalon lateral to the vomeronasal amygdala receiving input from the main olfactory bulb and projecting to the hypothalamus; (4) a medial amygdala receiving input from the anterior dorsal thalamus and projecting to the medial pallium, septum, and hypothalamus; (5) a ventromedial column formed by a nucleus accumbens and a ventral pallidum projecting to the central amygdala, hypothalamus, and posterior tubercle; (6) a lateral column constituting the dorsal striatum proper rostrally and the dorsal pallidum caudally, and a ventrolateral column constituting the ventral striatum. We conclude that the caudal mediolateral complex consisting of the extended central, vomeronasal, and olfactory amygdala of anurans represents the ancestral condition of the amygdaloid complex. During the evolution of the mammalian telencephalon this complex was shifted medially and involuted. The mammalian basolateral amygdala apparently is an evolutionary new structure, but the medial portion of the amygdalar complex of anurans reveals similarities in input and output with this structure and may serve similar functions.

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

    Directory of Open Access Journals (Sweden)

    Mário Ribeiro de Moura

    2010-12-01

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

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

    Science.gov (United States)

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

    2013-02-01

    The Coatzacoalcos Region in Veracruz, Mexico houses one of the most important industrial complexes in Mexico and Latin America. Lead is an ubiquitous environmental pollutant which represents a great risk to human health and ecosystems. Amphibian populations have been recognized as biomonitors of changes in environmental conditions. The purpose of this research is to measure exposure to lead and evaluate hematological and biochemical effects in specimens of giant toads (Rhinella marina) taken from three areas surrounding an industrial complex in the Coatzacoalcos River downstream. Lead levels in toads' blood are between 10.8 and 70.6 μg/dL and are significantly higher in industrial sites. We have found a significant decrease in the delta-aminolevulinic acid dehydratase (δ-ALAD) activity in blood from 35.3 to 78 % for the urban-industrial and industrial sites, respectively. In addition, we have identified a strong inverse relationship between the δ-ALAD activity and the blood lead levels (r = -0.84, p < 0.001). Hemoglobin and mean corpuscular hemoglobin levels, as well as the condition factor, are found to be lower at industrial sites compared with the reference sites. Our results suggest that the R. marina can be considered a good biomonitor of the δ-ALAD activity inhibition and hematological alterations at low lead concentrations.

  20. Non-target effects of a glyphosate-based herbicide on Common toad larvae (Bufo bufo, Amphibia) and associated algae are altered by temperature

    Science.gov (United States)

    Baier, Fabian; Gruber, Edith; Bondar-Kunze, Elisabeth; Ivanković, Marina; Mentler, Axel; Brühl, Carsten A.; Spangl, Bernhard

    2016-01-01

    Background Glyphosate-based herbicides are the most widely used pesticides in agriculture, horticulture, municipalities and private gardens that can potentially contaminate nearby water bodies inhabited by amphibians and algae. Moreover, the development and diversity of these aquatic organisms could also be affected by human-induced climate change that might lead to more periods with extreme temperatures. However, to what extent non-target effects of these herbicides on amphibians or algae are altered by varying temperature is not well known. Methods We studied effects of five concentrations of the glyphosate-based herbicide formulation Roundup PowerFlex (0, 1.5, 3, 4 mg acid equivalent glyphosate L−1 as a one time addition and a pulse treatment of totally 4 mg a.e. glyphosate L−1) on larval development of Common toads (Bufo bufo, L.; Amphibia: Anura) and associated algae communities under two temperature regimes (15 vs. 20 °C). Results Herbicide contamination reduced tail growth (−8%), induced the occurrence of tail deformations (i.e. lacerated or crooked tails) and reduced algae diversity (−6%). Higher water temperature increased tadpole growth (tail and body length (tl/bl) +66%, length-to-width ratio +4%) and decreased algae diversity (−21%). No clear relation between herbicide concentrations and tadpole growth or algae density or diversity was observed. Interactive effects of herbicides and temperature affected growth parameters, tail deformation and tadpole mortality indicating that the herbicide effects are temperature-dependent. Remarkably, herbicide-temperature interactions resulted in deformed tails in 34% of all herbicide treated tadpoles at 15 °C whereas no tail deformations were observed for the herbicide-free control at 15 °C or any tadpole at 20 °C; herbicide-induced mortality was higher at 15 °C but lower at 20 °C. Discussion These herbicide- and temperature-induced changes may have decided effects on ecological interactions in

  1. Non-target effects of a glyphosate-based herbicide on Common toad larvae (Bufo bufo, Amphibia and associated algae are altered by temperature

    Directory of Open Access Journals (Sweden)

    Fabian Baier

    2016-11-01

    Full Text Available Background Glyphosate-based herbicides are the most widely used pesticides in agriculture, horticulture, municipalities and private gardens that can potentially contaminate nearby water bodies inhabited by amphibians and algae. Moreover, the development and diversity of these aquatic organisms could also be affected by human-induced climate change that might lead to more periods with extreme temperatures. However, to what extent non-target effects of these herbicides on amphibians or algae are altered by varying temperature is not well known. Methods We studied effects of five concentrations of the glyphosate-based herbicide formulation Roundup PowerFlex (0, 1.5, 3, 4 mg acid equivalent glyphosate L−1 as a one time addition and a pulse treatment of totally 4 mg a.e. glyphosate L−1 on larval development of Common toads (Bufo bufo, L.; Amphibia: Anura and associated algae communities under two temperature regimes (15 vs. 20 °C. Results Herbicide contamination reduced tail growth (−8%, induced the occurrence of tail deformations (i.e. lacerated or crooked tails and reduced algae diversity (−6%. Higher water temperature increased tadpole growth (tail and body length (tl/bl +66%, length-to-width ratio +4% and decreased algae diversity (−21%. No clear relation between herbicide concentrations and tadpole growth or algae density or diversity was observed. Interactive effects of herbicides and temperature affected growth parameters, tail deformation and tadpole mortality indicating that the herbicide effects are temperature-dependent. Remarkably, herbicide-temperature interactions resulted in deformed tails in 34% of all herbicide treated tadpoles at 15 °C whereas no tail deformations were observed for the herbicide-free control at 15 °C or any tadpole at 20 °C; herbicide-induced mortality was higher at 15 °C but lower at 20 °C. Discussion These herbicide- and temperature-induced changes may have decided effects on ecological

  2. Non-target effects of a glyphosate-based herbicide on Common toad larvae (Bufo bufo, Amphibia) and associated algae are altered by temperature.

    Science.gov (United States)

    Baier, Fabian; Gruber, Edith; Hein, Thomas; Bondar-Kunze, Elisabeth; Ivanković, Marina; Mentler, Axel; Brühl, Carsten A; Spangl, Bernhard; Zaller, Johann G

    2016-01-01

    Glyphosate-based herbicides are the most widely used pesticides in agriculture, horticulture, municipalities and private gardens that can potentially contaminate nearby water bodies inhabited by amphibians and algae. Moreover, the development and diversity of these aquatic organisms could also be affected by human-induced climate change that might lead to more periods with extreme temperatures. However, to what extent non-target effects of these herbicides on amphibians or algae are altered by varying temperature is not well known. We studied effects of five concentrations of the glyphosate-based herbicide formulation Roundup PowerFlex (0, 1.5, 3, 4 mg acid equivalent glyphosate L -1 as a one time addition and a pulse treatment of totally 4 mg a.e. glyphosate L -1 ) on larval development of Common toads ( Bufo bufo , L.; Amphibia: Anura) and associated algae communities under two temperature regimes (15 vs. 20 °C). Herbicide contamination reduced tail growth (-8%), induced the occurrence of tail deformations (i.e. lacerated or crooked tails) and reduced algae diversity (-6%). Higher water temperature increased tadpole growth (tail and body length (tl/bl) +66%, length-to-width ratio +4%) and decreased algae diversity (-21%). No clear relation between herbicide concentrations and tadpole growth or algae density or diversity was observed. Interactive effects of herbicides and temperature affected growth parameters, tail deformation and tadpole mortality indicating that the herbicide effects are temperature-dependent. Remarkably, herbicide-temperature interactions resulted in deformed tails in 34% of all herbicide treated tadpoles at 15 °C whereas no tail deformations were observed for the herbicide-free control at 15 °C or any tadpole at 20 °C; herbicide-induced mortality was higher at 15 °C but lower at 20 °C. These herbicide- and temperature-induced changes may have decided effects on ecological interactions in freshwater ecosystems. Although no clear dose

  3. Foleyellides rhinellae sp. nov. (Nematoda, Onchocercidae) a new filaria parasitizing Rhinella marina (Anura, Bufonidae) in Mexico.

    Science.gov (United States)

    García-Prieto, Luis; Ruiz-Torres, Nallely; Osorio-Sarabia, David; Merlo-Serna, Aldo

    2014-09-01

    A new nematode species, Foleyellides rhinellae sp. nov. (Onchocercidae), is described from specimens found in the body cavity of the cane toad, Rhinella marina (Linnaeus) (Anura, Bufonidae), in the Laguna de Coyuca, Guerrero, in the Pacific slope of Mexico. The new species differs from the other nine species of Foleyellides by infecting bufonid anurans and by the number and arrangement of caudal papillae. Other distinguishing feature of the new species is the size of the left spicule (0.16-0.23 long), the smallest recorded among the species included in the genus. Foleyellides rhinellae sp. nov. is the second known species of the genus recorded from amphibians of Mexico.

  4. Melanophryniscus stelzneri spegazzinii (Anura: Bufonidae) en la República del Paraguay

    OpenAIRE

    Céspedez, Jorge Abel

    1996-01-01

    República del Paraguay, Dpto. Presidente Hayes, entre el Río Pilcomayo y el Río Confuso (24° 43' S, 58° 37' O). 2 ejemplares adultos, números MACN 07630 y 07631. Colectado por el Sr. Pedro Williams el 5 de mayo de 1940.

  5. Melanophryniscus devincenzii Kapplenbach, 1968 (Anura: Bufonidae. Primer registro para la República Argentina

    Directory of Open Access Journals (Sweden)

    Baldo, Diego

    1999-01-01

    Full Text Available Argentina, Misiones, Departamento Capital, Parque Provincial Fachinal (27° 30' S; 55° 44' W. 1 Agosto de 1998. Krauczuk y Cabanne. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia" Buenos Aires, Argentina (MACN 36856.

  6. Corneal curvatures and refractions of central American frogs.

    Science.gov (United States)

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

    1997-01-01

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

  7. 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

    Directory of Open Access Journals (Sweden)

    Nicola Novarini

    2010-07-01

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

  8. Peptidomic analysis of skin secretions of the Mexican burrowing toad Rhinophrynus dorsalis (Rhinophrynidae): Insight into the origin of host-defense peptides within the Pipidae and characterization of a proline-arginine-rich peptide.

    Science.gov (United States)

    Conlon, J Michael; Guilhaudis, Laure; Leprince, Jérôme; Coquet, Laurent; Mangoni, Maria Luisa; Attoub, Samir; Jouenne, Thierry; King, Jay D

    2017-11-01

    The Mexican burrowing toad Rhinophrynus dorsalis is the sole extant representative of the Rhinophrynidae. United in the superfamily Pipoidea, the Rhinophrynidae is considered to be the sister-group to the extant Pipidae which comprises Hymenochirus, Pipa, Pseudhymenochirus and Xenopus. Cationic, α-helical host-defense peptides of the type found in Hymenochirus, Pseudhymenochirus, and Xenopus species (hymenochirins, pseudhymenochirins, magainins, and peptides related to PGLa, XPF, and CPF) were not detected in norepinephrine-stimulated skin secretions of R. dorsalis. Skin secretions of representatives of the genus Pipa also do not contain cationic α-helical host-defense peptides which suggest, as the most parsimonious hypothesis, that the ability to produce such peptides by frogs within the Pipidae family arose in the common ancestor of (Hymenochirus+Pseudhymenochirus)+Xenopus after divergence from the line of evolution leading to extant Pipa species. Peptidomic analysis of the R. dorsalis secretions led to the isolation of rhinophrynin-27, a proline-arginine-rich peptide with the primary structure ELRLPEIARPVPEVLPARLPLPALPRN, together with rhinophrynin-33 containing the C-terminal extension KMAKNQ. Rhinophrynin-27 shows limited structural similarity to the porcine multifunctional peptide PR-39 but it lacks antimicrobial and cytotoxic activities. Like PR-39, the peptide adopts a poly-l-proline helix but some changes in the circular dichroism spectrum were observed in the presence of anionic sodium dodecylsulfate micelles consistent with the stabilization of turn structures. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Omamodal indication by sensitivity toadded artificial noise

    DEFF Research Database (Denmark)

    Juul, Martin O.; Olsen, Peter; Tarpø, Marius

    2017-01-01

    This paper presents a modal indicator for use in OMA identification techniques relying on the correlation function for extraction of parameters. We propose to add small amounts of artificial white Gaussian noise to the correlation function and measuring the sensitivity of the identified modes...

  10. conservation efforts of kihansi spray toad nectophrynoides ...

    African Journals Online (AJOL)

    Mr and Mrs Goboro

    Species conservation depends on the initiatives to restore or retain and sustainably use the environment ..... Increase of food production (fruit flies, springtails, Isopods and Crickets pinheads) also had a significant contribution to the rise of the KST population size. The data .... The UDSM is the technical adviser to the. NEMC ...

  11. How Preussag Became TUI : Kissing Too Many Toads Can Make You a Toad

    NARCIS (Netherlands)

    I. Dittmann (Ingolf); E.G. Maug (Ernst); C. Schneider (Christoph)

    2006-01-01

    textabstractIn the period 1997-2004, Preussag, a diversified German conglomerate of old economy businesses, changed itself into TUI, a company focused almost entirely on tourism and logistics. This paper analyzes how this strategy was executed and how it contributed to Preussag's underperformance of

  12. New host and distribution records for Aplectana hamatospicula (Ascaridida: Cosmocercidae) in Gastrophryne olivacea (Anura: Microhylidae) from the Great Plains U.S.A.

    Science.gov (United States)

    Vhora, M Suhail; Bolek, Matthew G

    2013-06-01

    Aplectana hamatospicula is a nematode that parasitizes the large intestine of anurans, and has been reported from bufonids, eleutherodactylids, hylids, microhylids, and ranids from North and Central America. Aplectana hamatospicula was first described, over 70 yr ago, from Hyla eximia and Bufo peltocephalus from Mexico and Cuba, respectively, and reported from Gastrophryne carolinensis from Florida. Since then there have been no reports of this nematode in North America north of Mexico. The life cycle of A. hamatospicula is not known, and there is limited information on Aplectana spp. from North America. During 2010-2011, we collected 351 anurans of 8 species from 4 locations in Stillwater, Payne County, Oklahoma, U.S.A., and examined them for the presence of Aplectana spp. Of the 8 species of anurans surveyed, A. hamatospicula infected only the Great Plains narrowmouth toad (Gastrophryne olivacea). The prevalence of A. hamatospicula was 85.7% (12/14) with a mean abundance of 28.4 + 24.0 and a mean intensity of 33.1 + 22.8 worms per infected toad. We provide new morphological measurements for male and female A. hamatospicula along with new locality records for this nematode in North America.

  13. Acerca de la localidad tipo y la distribución geográfica de Melanophryniscus klappenbachi Prigione & Langone, 2000 (Anura: Bufonidae

    Directory of Open Access Journals (Sweden)

    Baldo, Diego

    2001-12-01

    Full Text Available Dada la distribución geográfica de esta especie en Argentina, Prigioni y Langone (op. cit. sugieren que las citas de M. stelzneri fulvoguttatus para las provincias de Santa Fe (Baldo y Arzamendia, 1997 y Santiago del Estero (Basso y Williams, 1996 y para la localidad formoseña de Bartolomé de las Casas (Gallardo, 1961; 1966 debían ser reexaminadas. Del examen del material en el que se basaron dichas citas, concluyo que pertenecen a M. klappenbachi.

  14. Using combined morphological, allometric and molecular approaches to identify species of the genus Raillietiella (Pentastomida.

    Directory of Open Access Journals (Sweden)

    Crystal Kelehear

    Full Text Available Taxonomic studies of parasites can be severely compromised if the host species affects parasite morphology; an uncritical analysis might recognize multiple taxa simply because of phenotypically plastic responses of parasite morphology to host physiology. Pentastomids of the genus Raillietiella are endoparasitic crustaceans primarily infecting the respiratory system of carnivorous reptiles, but also recorded from bufonid anurans. The delineation of pentastomids at the generic level is clear, but the taxonomic status of many species is not. We collected raillietiellids from lungs of the invasive cane toad (Rhinella marina, the invasive Asian house gecko (Hemidactylus frenatus, and a native tree frog (Litoria caerulea in tropical Australia, and employed a combination of genetic analyses, and traditional and novel morphological methods to clarify their identity. Conventional analyses of parasite morphology (which focus on raw values of morphological traits revealed two discrete clusters in terms of pentastome hook size, implying two different species of pentastomes: one from toads and a tree frog (Raillietiella indica and another from lizards (Raillietiella frenatus. However, these clusters disappeared in allometric analyses that took pentastome body size into account, suggesting that only a single pentastome taxon may be involved. Our molecular data revealed no genetic differences between parasites in toads versus lizards, confirming that there was only one species: R. frenatus. This pentastome (previously known only from lizards clearly is also capable of maturing in anurans. Our analyses show that the morphological features used in pentastomid taxonomy change as the parasite transitions through developmental stages in the definitive host. To facilitate valid descriptions of new species of pentastomes, future taxonomic work should include both morphological measurements (incorporating quantitative measures of body size and hook bluntness and

  15. Health-related quality of life for immediate versus delayed androgen-deprivation therapy in patients with asymptomatic, non-curable prostate cancer (TROG 03.06 and VCOG PR 01-03 [TOAD]): a randomised, multicentre, non-blinded, phase 3 trial.

    Science.gov (United States)

    Duchesne, Gillian M; Woo, Henry H; King, Madeleine; Bowe, Steven J; Stockler, Martin R; Ames, Alice; D'Este, Catherine; Frydenberg, Mark; Loblaw, Andrew; Malone, Shawn; Millar, Jeremy; Tai, Keen Hun; Turner, Sandra

    2017-09-01

    Androgen-deprivation therapy in patients with prostate cancer who have relapsed with rising prostate-specific antigen concentration only (PSA-only relapse), or with non-curable but asymptomatic disease at diagnosis, could adversely affect quality of life at a time when the disease itself does not. We aimed to compare the effect of immediate versus delayed androgen-deprivation therapy on health-related quality of life over 5 years in men enrolled in the TOAD (Timing of Androgen Deprivation) trial. This randomised, multicentre, open-label, phase 3 trial done in 29 public and private cancer centres across Australia, New Zealand, and Canada compared immediate with delayed androgen-deprivation therapy in men with PSA-only relapse after definitive treatment, or de-novo non-curable disease. Patients were randomly assigned (1:1) with a database-embedded, dynamically balanced algorithm to immediate androgen-deprivation therapy (immediate therapy group) or to delayed androgen-deprivation therapy (delayed therapy group). Any type of androgen-deprivation therapy was permitted, as were intermittent or continuous schedules. The European Organisation for Research and Treatment of Cancer (EORTC) quality-of-life questionnaires QLQ-C30 and PR25 were completed before randomisation, every 6 months for 2 years, and annually for a further 3 years. The primary outcome of the trial, reported previously, was overall survival, with global health-related quality of life at 2 years as a secondary endpoint. Here we report prespecified secondary objectives of the quality-of-life endpoint. Analysis was by intention to treat. Statistical significance was set at p=0·0036. The trial was registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12606000301561, and ClinicalTrials.gov, number NCT00110162. Between Sept 3, 2004, and July 13, 2012, 293 men were recruited and randomly assigned; 151 to the delayed therapy group and 142 to the immediate therapy group. There was no

  16. Glucose tolerance in the toad Bufo gutturalis (power)

    African Journals Online (AJOL)

    tions in blood glucose levels amongst different species of amphibians (Marvin & Frye 1974). The significance of these variations is difficult to evaluate in view of different experimental conditions and methods of analysis employed by investigators. There is a great disparity in the number of investiga- tions on sugar tolerance ...

  17. Middle Breton prezeffan 'vermin, toad, lizard'

    DEFF Research Database (Denmark)

    Jørgensen, Anders Richardt

    2012-01-01

    Middelbretonsk prezeffan, hidtil set som en uforklaret variant af preffan 'kryb' (diminutiv af preff 'orm'), tolkes nu i stedet som et selvstændigt leksem. Det afledes af et ældre *pezreffan, som svarer direkte til kornisk pedrevan 'firben'. En videre analyse identificerer første del af ordet som...

  18. Toad-Ally Cool Math and Science Integration

    Science.gov (United States)

    Brkich, Katie; Allen, Melony; Huffling, Lacey; Matthews, Catherine

    2017-01-01

    "Hop to It," a week-long herpetology-focused summer STEM camp for rising fourth-, fifth-, and sixth-grade girls, provided young females with authentic, hands-on science experiences, allowing them to develop the habits of thought and processes of action used by STEM field experts while also engaging and sustaining their interest in the…

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

    Data.gov (United States)

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

  20. A new species of the Rhinella margaritifera species group (Anura, Bufonidae) from the montane forest of the Selva Central, Peru

    Science.gov (United States)

    Moravec, Jiří; Lehr, Edgar; Cusi, Juan Carlos; Córdova, Jesús H.; Gvoždík, Václav

    2014-01-01

    Abstract We describe a new species of the bufonid toad genus Rhinella from transition montane forest of the buffer zones of the Yanachaga-Chemillén National Park and the Pui Pui Protected Forest (eastern slopes of Andes, Selva Central, Peru). The new species belongs to the Rhinella margaritifera species group (confirmed by mtDNA data) and differs from all its members by the absence of tympanic membrane and tympanic annulus. It is characterized by medium size (SVL 57.5–65.5 mm, n = 5), moderately developed cranial crests, absence of neural crest of vertebrae, absence of bone protrusion at angle of jaw, presence of lateral rows of enlarged tubercles, and absence of subgular vocal sac and vocal slits in males. In addition, based on the molecular phylogenetic analyses of selected Rhinella species we propose the monophylum containing R. chavin, R. festae, R. macrorhina, R. manu, R. nesiotes, R. rostrata, and R. yanachaga as a new species group under the name Rhinella festae species group. PMID:24493953

  1. A new species of nematode (Molineidae) from Rhinella marina (Amphibia: Bufonidae) in Guerrero, México.

    Science.gov (United States)

    Ruiz-Torres, Nallely; García-Prieto, Luis; Osorio-Sarabia, David; Violante-González, Juan

    2013-06-01

    Oswaldocruzia lamotheargumedoi n. sp., inhabiting the intestine of the cane toad, Rhinella marina (L.), in Laguna de Coyuca, Guerrero, México, is described here. The new species differs from 10 congeners infecting bufonid hosts because it has a type I bursa. In contrast, 7 of these species have type II bursa and 3 more a type III bursa. The species most similar to the species described herein is Oswaldocruzia pipiens Walton, 1929 . These 2 species share traits such as body size, bursa type, presence of cervical alae, and dorsal ray morphology. Nevertheless, both species can be distinguished based on the number of synlophe ridges at mid-body (54-56 for O. lamotheargumedoi vs. 45-48 for O. pipiens) and by the presence of a chitinous support in the long, and well developed, cervical alae of O. pipiens. In the new species, these structures are short, poorly developed, and lack chitinous support. Previous records of species of Oswaldocruzia in México include Oswaldocruzia subauricularis (Rudolphi, 1819) Travassos, 1917 in the Neotropical Realm and O. pipiens in the Nearctic.

  2. Morphological and molecular data to describe a hybrid population of the Common toad (Bufo bufo) and the Spined toad (Bufo spinosus) in western France

    NARCIS (Netherlands)

    Trujillo, T.; Gutiérrez-Rodríguez, J.; Arntzen, J.W.; Martínez-Solano, I.

    2017-01-01

    The use of hyper-variable markers across species is often hindered by low cross-species amplification success, a reduced level of polymorphism or a high frequency of null alleles. However, optimizing sets of reliable and informative markers that can be consistently amplified and scored across taxa

  3. Characterization and seasonal changes in LHβ and FSHβ mRNA of Rhinella arenarum (Amphibia, Anura).

    Science.gov (United States)

    Volonteri, M Clara; Regueira, Eleonora; Scaia, M Florencia; Ceballos, Nora R

    2013-06-15

    In anurans, two types of gonadotropins were described in several species of Ranidae and Pipidae families but only in one of the Bufonidae family. Rhinella arenarum is a bufonid that have the lowest concentration of plasma androgens during the breeding. The objective of this paper was to characterize the cDNA sequence of β subunit of LH and FSH from toad pituitary and study seasonal variation in gonadotropins mRNA using quantitative real-time RT-PCR. The LHβ cDNA is a 636 bp sequence containing an open reading frame (ORF), 45 bp of 5'-untranslated region (UTR) and 174 bp of 3'-UTR. The ORF encodes for a signal peptide of 26 amino acids and a mature protein of 113 amino acids with one N-glycosylation site at the 34th position. The FSHβ cDNA sequence is a 535 bp fragment containing an ORF, 8 bp of 5'-UTR and 152 bp of 3'-UTR. The ORF encodes for a signal peptide of 20 amino acids and a mature protein of 104 amino acids with two N-glycosylation sites at 25th and 42nd positions. Multiple alignments of aminoacid deduced sequences of LHβ and FSHβ (teleosts, amphibians, birds, mammals) showed that all the tetrapods studied conserve 12 cysteins and one (LH) or two (FSH) N-Glycosylation sites. LHβ is closer to teleosts than to mammals and birds while FSHβ is closer to mammals. The analysis of seasonal changes in LHβ and FSHβ mRNA indicates that transcript levels have seasonal variations and that the profile of androgens is opposite to that of the gonadotropins mRNA. Copyright © 2013 Elsevier Inc. All rights reserved.

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

    OpenAIRE

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

    2003-01-01

    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 airfl...

  5. Soil organic matter content effects on dermal pesticide bioconcentration in American toads (Bufo americanus).

    Science.gov (United States)

    Pesticides have been implicated as a major factor in global amphibian declines and may pose great risk to terrestrial phase amphibians moving to and from breeding ponds on agricultural landscapes. Dermal uptake from soil is known to occur in amphibians, but predicting pesticide a...

  6. Effects of fluoride on morphology, growth, development, and thyroid hormone of Chinese toad (Bufo gargarizans) embryos.

    Science.gov (United States)

    Zhang, Yuhui; Xie, Lei; Li, Xinyi; Chai, Lihong; Chen, Mengxing; Kong, Xiaojing; Wang, Qingqing; Liu, Jingfei; Zhi, Lijuan; Yang, Chang; Wang, Hongyuan

    2017-10-12

    Excessive fluoride in natural water ecosystem has the potential to detrimentally affect amphibians, but little is known of such effects or underlying mechanisms in Bufo gargarizans embryos. In the present study, the effects of fluoride exposure on B. gargarizans embryos were investigated. First, fluoride teratogenic experiment showed that the 9 days EC50 of fluoride on B. gargarizans embryos was 177.62 mg/L. Then, we studied the sublethal effects of fluoride on B. gargarizans embryos at control, 0.7, 4.1, 19.6, 41.9, and 62.7 mg/L fluoride concentration. Malformation, growth, and development of embryos were monitored, and type 2 and 3 iodothyronine deiodinase (Dio2 and Dio3), thyroid hormone receptors (TRα and TRβ) mRNA levels were measured. Our results showed the morphological malformations, such as tail curvature (lordosis), edema, cuticularized ciliated cells, and hyperplasia were occurred during fluoride exposure. Growth and development were all inhibited at 19.5, 41.9, and 62.7 mg/L fluoride-treated groups after 9 days' exposure. According to real-time PCR results, exposure to fluoride upregulated Dio3 and TRβ mRNA expression and downregulated Dio2 and TRα mRNA level. All above indicated that excessive fluoride could induce morphology malformations, inhibit embryonic growth and development, and disrupt the normal function of maternal thyroid hormone in B. gargarizans embryos. Environ. Mol. Mutagen., 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  7. 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 MojaveDesert is organized by sequencing a portion of mitochondrial DNA control region for 831 toadscollected from 43 sites around Las Vegas, Nevada. We grouped these collecti...

  8. Chronic effects of triclosan on embryonic development of Chinese toad, Bufo gargarizans.

    Science.gov (United States)

    Chai, Lihong; Wang, Hongyuan; Zhao, Hongfeng; Deng, Hongzhang

    2016-10-01

    Triclosan (TCS) is commonly used worldwide in a range of personal care and sanitizing products. The aim of this study was to evaluate potential effects of TCS exposure on embryonic development of Bufo gargarizans, an endemic frog species in China. Standard Gosner stage 3 B. gargarizans embryos were exposed to 10 ~ 150 μg/L TCS during embryogenesis. Survival, total length, weight, developmental stage, duration of different embryo stages, malformation, and type II and III deiodinase (D2 and D3) expression were measured. Inhibitory effects on embryo developmental stage, total length and weight were found at 30 ~ 150 μg/L TCS. Moreover, the duration of embryonic development was increased at gastrula, neural, circulation, and operculum development stage in TCS-treated groups. In addition, TCS exposure induced morphological malformations in B. gargarizans embryos, which are characterized by hyperplasia, abdominal edema, and axial flexures. Furthermore, our results showed that the expression of D2 in embryos was probably down-regulated at 60 and 150 μg/L TCS, but its spatial expression patterns was not affected by TCS. In summary, our study suggested that TCS exposure not only resulted in delayed growth and development but also caused teratogenic effects in B. gargarizans embryos, and the developmental effects of TCS at high concentrations may be associated with disruption of THs homeostasis. Although further studies are necessary, the present findings could provide a basis for understanding on harmful effects and the potential mechanisms of TCS in amphibian embryos.

  9. Hematotoxic and biochemical effects of UVA on the Egyptian toad (Bufo regularis).

    Science.gov (United States)

    Sayed, Alaa El-Din H

    2016-01-01

    To study the adverse impacts of ultraviolet radiation-A (UVA 320-400 nm) on some hematological and biochemical parameters of Bufo regularis was considered. Samples were classified into four groups: (i) Control; (ii) ultraviolet radiation (UVR)-treated group (for 3 days/for 15 min/day); (iii) UVR-treated group (for 3 days/for 30 min/day); and (iv) (for 3 days/for 60 min/day). The destructive effects of UVA radiation was evaluated by red blood cells (RBC) count, hemoglobin content (Hb), hematocrite (Ht), erythrocytic indices, white blood cells (WBC) count, total protein, glucose, aspartic amino transferase (AST), alanine amino transferase (ALT), alkaline phosphatase (ALP), lactate dehyderogenase (LDH), glucose-6-phosphate dehyderogenase (G6PDH) and total bilribuin. No mortality was observed. However, some physiological effects after the exposure to UVA were reported. The UVA-induced malformations recorded in the red blood cells included crenated cells (Cr), Acanthocytes (Ac), tear drop-like cells (Tr) and sickle cells (Sk). The present study revealed the exposure to UVA from 15-60 min/day for three days could promote several biochemical and physiological disturbances as well as some changes in RBC.

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

    Science.gov (United States)

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

    2006-01-01

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

  11. The ontogeny of kin recognition in tadpoles of the toad Bufo ...

    Indian Academy of Sciences (India)

    When tested in tanks with empty end compartments, the test tadpoles showed random distribution and thus no bias for the apparatus or the procedure. In the presence of kin/non-kin in the end compartments a significantly greater number of test tadpoles spent the majority of the time near familiar or unfamiliar kin rather than ...

  12. Within- and among-population variation in chytridiomycosis-induced mortality in the toad Alytes obstetricans.

    Directory of Open Access Journals (Sweden)

    Ursina Tobler

    Full Text Available BACKGROUND: Chytridiomycosis is a fungal disease linked to local and global extinctions of amphibians. Susceptibility to chytridiomycosis varies greatly between amphibian species, but little is known about between- and within-population variability. However, this kind of variability is the basis for the evolution of tolerance and resistance evolution to disease. METHODOLOGY/PRINCIPAL FINDINGS: In a common garden experiment, we measured mortality after metamorphosis of Alytes obstetricans naturally infected with Batrachochytrium dendrobatidis. Mortality rates differed significantly among populations and ranged from 27 to 90%. Within populations, mortality strongly depended on mass at and time through metamorphosis. CONCLUSIONS/SIGNIFICANCE: Although we cannot rule out that the differences observed resulted from differences in skin microbiota, different pathogen strains or environmental effects experienced by the host or the pathogen prior to the start of the experiment, we argue that genetic differences between populations are a likely source of at least part of this variation. To our knowledge, this is the first study showing differences in survival between and within populations under constant laboratory conditions. Assuming that some of this intraspecific variation has a genetic basis, this may suggest that there is the potential for the evolution of resistance or tolerance, which might allow population persistence.

  13. 75 FR 37358 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Arroyo Toad

    Science.gov (United States)

    2010-06-29

    ...) mining activities; (5) road construction projects; (6) utility and other infrastructure projects; (7..., changes in water supply, grazing and mining activities, road construction projects, utility and other... comments on Docket No. FWS-R8- ES-2009-0069. U.S. mail or hand-delivery: Public Comments Processing, Attn...

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

    Directory of Open Access Journals (Sweden)

    Pozzi, Andrea Gabriela

    2012-12-01

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

  15. induced gastric acid secretion in the common african toad – bufo

    African Journals Online (AJOL)

    admin

    generation modulates the inhibition of interleukin-1-Beta of pentagastrin – stimulated gastric acid secretion in the rat. Gut 34: S11. Bilski, J., Konturek, S. J, Cieszkowski, M.,. Czarnobilski, K.. and Pawlik, W. W.. (1994). Endogenous nitric oxide in the regulation of gastric acid secretion, gastrin release and blood flow. Biomed.

  16. SPATIAL SCALE OF AUTOCORRELATION IN WISCONSIN FROG AND TOAD SURVEY DATA

    Science.gov (United States)

    The degree to which local population dynamics are correlated with nearby sites has important implications for metapopulation dynamics and landscape management. Spatially extensive monitoring data can be used to evaluate large-scale population dynamic processes. Our goals in this ...

  17. Behaviour of migrating toads under artificial lights differs from other phases of their life cycle

    NARCIS (Netherlands)

    Grunsven, Van Roy H.A.; Creemers, Raymond; Joosten, Kris; Donners, Maurice; Veenendaal, Elmar M.

    2017-01-01

    During annual spring migration in Western Europe many amphibians are killed by traffic when they cross roads moving to reproduction sites. Especially in urban settings these roads are often equipped with street lighting. The response of amphibians to this light during migration is however poorly

  18. The complete mitochondrial genome of the toad-headed lizard, Phrynocephalus albolineatus (Reptilia, Squamata, Agamidae).

    Science.gov (United States)

    Shao, Min; Ma, Li; Zhang, Guangzheng; Wang, Zheng

    2017-01-01

    In this study, we report the complete mitochondrial genome of Phrynocephalus albolineatus (Reptilia, Squamata, Agamidae), which is a circular molecule of 16 808 bp in size and consists of 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs, and 2 non-coding sequence (D-loop). The mitogenome of P. albolineatus was similar to the typical mtDNA of vertebrates in gene arrangement and composition. The control region was comprised by two parts, one (992 bp) between tRNA-Phe and 12S rRNA, and the other (650 bp) between tRNA-Thr and tRNA-Pro. The A + T content of overall base of H-strand is 63.1% (T: 26.7%, C: 24.6%, A: 36.4%, G: 12.3%). The whole mitogenomic sequence of P. albolineatus provides powerful data to study the molecular systematic, population genetics and phylogeography of Squamata.

  19. 76 FR 7245 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Arroyo Toad

    Science.gov (United States)

    2011-02-09

    ... Designated as Subunit 11b: 844 Subunit 11b: 844 (341). (341). 12. Lower Santa Margarita River San Diego...: 615 (248). (248). 13. Upper Santa Margarita River Riverside, San Entire Unit Included as Unit...

  20. Factors influencing the toxicity of Headline® fungicides to terrestrial stage toads.

    Science.gov (United States)

    Cusaac, J Patrick W; Mimbs, William H; Belden, Jason B; Smith, Loren M; McMurry, Scott T

    2017-10-01

    Amphibians are susceptible to exposure from contaminants via multiple pathways. Pyraclostrobin fungicides have been shown to be toxic to terrestrial amphibians at environmentally relevant concentrations; however, these studies did not account for factors that may influence exposure and effects, such as fungicide formulation, age of the individual, exposure route, and physiological state of the individual. We examined Headline® and Headline AMP® fungicide toxicity to adult Anaxyrus cognatus and Anaxyrus woodhousii by direct overspray, as well as acute toxicity of Headline AMP to juvenile A. cognatus through direct overspray, previously exposed soils, and diet. We also assessed effects of hydration state on fungicide toxicity in juvenile A. cognatus and sublethal effects of fungicide exposure on prey-orientation ability of juvenile A. cognatus. Neither formulation of Headline caused mortality of adult A. cognatus and A. woodhousii at up to 5 times the maximum label rate in North American corn (1052 and 879 mL formulation/ha for Headline AMP and Headline fungicides, respectively, corresponding to 1.52 and 2.2 μg pyraclostrobin/cm(2) , respectively). Exposures of juvenile A. cognatus to Headline AMP via direct overspray and previously exposed soils (2 types) resulted in median lethal rate (LR50) values of 2.4, 3.34, and 3.61 μg pyraclostrobin/cm(2) , respectively. Dietary Headline AMP exposure was not toxic, prey-orientations were not influenced by exposure, and effects were similar between dehydrated and hydrated treatments (LR50 = 2.4 and 2.3 μg pyraclostrobin/cm(2) , respectively). These results, combined with exposure concentrations reported in previous studies, suggest that risk of acute mortality for amphibians in terrestrial environments is low and is dictated by body size and site-specific factors influencing exposure. Environ Toxicol Chem 2017;36:2679-2688. © 2017 SETAC. © 2017 SETAC.

  1. An Examination of Morphometric Variations in a Neotropical Toad Population (Proceratophrys cristiceps, Amphibia, Anura, Cycloramphidae)

    Science.gov (United States)

    Vieira, Kleber S.; Arzabe, Cristina; Hernández, Malva I. M.; Vieira, Washington L. S.

    2008-01-01

    The species Proceratophrys cristiceps belongs to the genus Proceratophrys within the family Cycloramphidae. These amphibians are found exclusively in South America in the morphoclimatic domain of the semi-arid depression zones in northeastern Brazil known as the Caatinga. We examined intrapopulational variation using univariate and multivariate statistics with traditional and geometric morphometrics, which supported the existence of two morphotypes of this species. Our results indicated significant degrees of variation in skeletal characteristics between some natural populations of this species. Careful analyses of variability levels are fundamental to avoid taxonomic errors, principally in populations that demonstrate characteristics intimately associated with their area of occurrence, as is the case of Proceratophrys cristiceps. PMID:19088855

  2. Nickel affects gill and muscle development in oriental fire-bellied toad (Bombina orientalis) embryos

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chan Jin; Song, Sang Ha; Kim, Dae Han; Gye, Myung Chan, E-mail: mcgye@hanyang.ac.kr

    2017-01-15

    Highlights: • Nickel inhibited the development of external gill in B. orientalis embryos. • The 168 h LC{sub 50} and EC{sub 50} values of nickel were 33.8 and 5.4 μM, respectively, in embryos. • Nickel induced abnormal tail development of embryos. • NF stage 26–31 was the most sensitive window for embryos to nickel exposure. • Nickel affected the calcium-dependent myogenic gene expression in embryos. - Abstract: The developmental toxicity of nickel was examined in the embryos of Bombina orientalis, a common amphibian in Korea. Based on a standard frog embryo teratogenesis assay, the LC{sub 50} and EC{sub 50} for malformation of nickel after 168 h of treatment were 33.8 μM and 5.4 μM, respectively. At a lethal concentration (100 μM), nickel treatment decreased the space between gill filaments and caused epithelial swelling and abnormal fusion of gill filaments. These findings suggest that nickel affects the functional development of gills, leading to embryonic death. At sublethal concentrations (1–10 μM), nickel produced multiple embryonic abnormalities, including bent tail and tail dysplasia. At 10 μM, nickel significantly decreased tail length and tail muscle fiber density in tadpoles, indicating inhibition of myogenic differentiation. Before hatching, the pre-muscular response to muscular response stages (stages 26–31) were the most sensitive period to nickel with respect to tail muscle development. During these stages, MyoD mRNA was upregulated, whereas myogenic regulatory factor 4 mRNA was downregulated by 0.1 μM nickel. Calcium-dependent kinase activities in muscular response stage embryos were significantly decreased by nickel, whereas these activities were restored by exogenous calcium. In tadpoles, 10 μM nickel significantly decreased the expression of the myosin heavy chain and the 12/101 muscle marker protein in the tail. Expression was restored by exogenous calcium. Our results indicate that nickel affects muscle development by disrupting calcium-dependent myogenesis in developing B. orientalis embryos.

  3. The ontogeny of kin recognition in tadpoles of the toad Bufo ...

    Indian Academy of Sciences (India)

    Unknown

    Eggs of each clutch were placed separately in plastic containers with. 5 litres aged (dechlorinated) tap water until hatching or until subjecting them to different rearing conditions. The eggs usually hatched ... different parental lines (20/egg mass) and for the late tests ... separated at stage 12 (yolk plug formation) and reared.

  4. Effect of lanthanum on urinary acidification and sodium transport by the turtle and toad bladder.

    Science.gov (United States)

    Sabatini, S; Arruda, J A

    1984-01-01

    Lanthanum has been extensively used to evaluate the role of extracellular and membrane-bound calcium on several aspects of cell function. In the present study we evaluated the effect of mucosal or serosal addition of lanthanum on Na and H+ transport by the turtle bladder, in vitro, to gain insight concerning the role of calcium on these processes. Mucosal addition of lanthanum was associated with a decrease in Na transport and H+ secretion. The inhibition was of rapid onset, achieving a maximal inhibition at 10(-3) M for H+ secretion and 5 X 10(-4) for Na transport. The effect was rapidly and totally reversible with the removal of lanthanum. The mucosal effect of lanthanum addition was observed only at pH 7.4 for H+ secretion and at pH 7.4, 6.4, and 5.4 for Na transport. Agents capable of 'screening' the negative change of membrane proteins, such as cadmium or zinc, could neither elicit nor prevent the effect of lanthanum on H+ secretion. The effect of serosal addition of lanthanum on H+ or Na transport was different from that observed with mucosal addition; it was of slow onset, smaller magnitude, partially reversible, and only elicited by high concentrations (10 mM) of lanthanum. Serosal addition of lanthanum caused an early increase and a late decrease in radioactive calcium efflux. Mucosal addition of lanthanum caused an increase in calcium efflux. The data demonstrate that lanthanum inhibits Na and H+ transport in the turtle bladder and suggest that the mechanism of action of lanthanum is the result of either displacement of membrane-bound calcium or altered cell membrane permeability to calcium.

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

    DEFF Research Database (Denmark)

    Thomsen, Steffen Nyegaard; Wang, Tobias; Kristensen, Torsten

    Red blood cells (RBC) from reptiles appear not to express regulatory volume increase (RVI) upon shrinkage (Kristensen et al., 2008). In other vertebrates, the RVI response is primarily mediated by activation of the Na+/H+ exchanger (NHE-1) and we, therefore decided to investigate whether red cell...

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

    Science.gov (United States)

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

    2015-01-01

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

  7. 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...

  8. Agricultural intensity in ovo affects growth, metamorphic development and sexual differentiation in the common toad (Bufo bufo).

    Science.gov (United States)

    Orton, Frances; Routledge, Edwin

    2011-06-01

    Pollution was cited by the Global Amphibian Assessment to be the second most important cause of amphibian decline worldwide, however, the effects of the agricultural environment on amphibians are not well understood. In this study, spawn from Bufo bufo was taken from four sites in England and Wales with varying intensities of arable agriculture. Spawn was either placed in tanks containing aged tap water (ex-situ, five replicates) or in cages at the native site (caged, five replicates). Hatching success, abnormal tadpoles, and forelimb emergence were recorded during the larval stage. Individuals were also sampled at five time points (TP) during development (5-, 7-, 9-, 12-, 15-weeks post-hatch) and analysed for morphological parameters. The thyroids (TP2) and the gonads (TP3,4,5) were also analysed histologically. With the exception of the thyroid histopathology, all analysed endpoints were significantly different between ex-situ individuals reared under identical conditions from the different sites. In addition, intensity of arable agriculture had a negative effect on growth and development. At one site, despite distinct rearing conditions, a high level of intersex (up to 42%) and similar sex ratios were observed in both ex-situ and caged individuals. Taken together, these data suggest that maternal exposure and/or events in ovo had a much larger effect on growth, metamorphic development, and sexual differentiation in B. bufo than the ambient environment. This could have important implications for traditional exposure scenarios that typically begin at the larval stage. Intersex is reported for the first time in European amphibians in situ, highlighting the potential use of distinct populations of amphibians in fundamental research into the aetiology of specific developmental effects in wild amphibians.

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

    Data.gov (United States)

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

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

    Directory of Open Access Journals (Sweden)

    Noemi M. Fernandes

    2011-12-01

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

  11. New species of Aplectana (Ascaridida: Cosmocercidae) in the toads, Rhinella granulosa and Rhinella schneideri (Anura: Bufonidae) from northern Argentina.

    Science.gov (United States)

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

    2008-12-01

    Aplectana adaechevarriae n. sp., from the large intestine of Rhinella granulosa and Rhinella schneideri, is described and illustrated. Of the 43 nominal species of Aplectana, A. adaechevarriae n. sp. represents the 23rd Neotropical species and the third species reported from Argentina. Of the Neotropical species, only 4, Aplectana elenae, Aplectana hylambatis, Aplectana raillieti, and A. adaechevarriae n. sp., have 8 pairs of preanal papillae. Aplectana adaechevarriae lacks a median preanal papilla; the other 3 species possess a median preanal papilla.

  12. Late Miocene diversification and phylogenetic relationships of the huge toads in the Rhinella marina (Linnaeus, 1758) species group (Anura: Bufonidae).

    Science.gov (United States)

    Maciel, Natan Medeiros; Collevatti, Rosane Garcia; Colli, Guarino Rinaldi; Schwartz, Elisabeth Ferroni

    2010-11-01

    We investigated the phylogeny and biogeography of the Rhinella marina group, using molecular, morphological, and skin-secretion data, contributing to an understanding of Neotropical faunal diversification. The maximum-parsimony and Bayesian analyzes of the combined data recovered a monophyletic R. marina group. Molecular dating based on Bayesian inferences and fossil calibration placed the earliest phylogenetic split within the R. marina group at ∼ 10.47 MYA, in the late Miocene. Two rapid major diversifications occurred from Central Brazil, first northward (∼ 8.08 MYA) in late Miocene and later southward (∼ 5.17 MYA) in early Pliocene. These results suggest that barriers and dispersal routes created by the uplift of Brazilian Central Shield and climatic changes explain the diversification and current species distributions of the R. marina group. Dispersal-vicariance analyzes (DIVA) indicated that the two major diversifications of the R. marina group were due to vicariance, although eleven dispersals subsequently occurred. Copyright © 2010 Elsevier Inc. All rights reserved.

  13. A new species of semiarboreal toad of the Rhinella festae group (Anura, Bufonidae) from the Cordillera Azul National Park, Peru

    Science.gov (United States)

    Cusi, Juan C.; Moravec, Jiří; Lehr, Edgar; Gvoždík, Václav

    2017-01-01

    Abstract A new semiarboreal species of the Rhinella festae group is described from montane forests of the Cordillera Azul National Park between 1245 and 1280 m a.s.l. in the Cordillera Oriental, San Martín region, northern Peru. The new species is morphologically and genetically compared with members of the Rhinella acrolopha group (former genus Rhamphophryne) and members of the R. festae group. The new species is characterized by its large size (female SVL 47.1–58.3 mm, n = 4), eight presacral vertebrae, fusion of the sacrum and coccyx, long protuberant snout, snout directed slightly anteroventral in lateral view, cranial crests moderately developed, absence of occipital crest, presence of tympanic membrane, dorsolateral rows of small conical tubercles extending from parotoid gland to groin, hands and feet with long digits, fingers basally webbed and toes moderately webbed. Phylogenetically it is a member of the R. festae group which is most closely related to R. chavin and R. yanachaga from Peru. Morphologically the new species shares similarities with R. tenrec and R. truebae, members of the R. acrolopha group from Colombia. PMID:28769671

  14. A new species of upland Stream Toad of the genus Ansonia Stoliczka, 1870 (Anura: Bufonidae) from northeastern Peninsular Malaysia.

    Science.gov (United States)

    Chan, Kin Onn; Wood, Perry L; Anuar, Shahrul; Muin, Mohd Abdul; Quah, Evan S H; Sumarli, Alexandra X Y

    2014-02-12

    A new species of Ansonia is described based on genetic and morphological differentiation. Ansonia lumut sp. nov. is most closely related to three other Peninsular Malaysian species, A. penangensis, A. malayana, and A. jeetsukumarani but differs from these and other congeners by at least 6.9% sequence divergence at the 12S, 16S rRNA and t-RNA-val genes and the following combination of morphological characters: (1) SVL 21.0-23.6 mm in males, 27.7-31.6 mm in females; (2) first finger shorter than second; (3) interorbital and tarsal ridges absent; (4) light interscapular spot absent; (5) presence of large, yellow rictal tubercle; (6) dorsum black with greenish-yellow reticulations; (7) flanks with small yellow spots; (8) fore and hind limbs with yellow cross-bars; and (9) venter light gray with fine, white spotting.

  15. Thermal tolerance in the Andean toad Rhinella spinulosa (Anura: Bufonidae) at three sites located along a latitudinal gradient in Chile.

    Science.gov (United States)

    Riquelme, Nicza Alveal; Díaz-Páez, Helen; Ortiz, Juan Carlos

    2016-08-01

    Rhinella spinulosa is one of the anuran species with the greatest presence in Chile. This species mainly inhabits mountain habitats and is distributed latitudinally along the western slope of the Andes Range. These habitats undergo great temperature fluctuations, exerting pressure on the amphibian. To identify the physiological strategies and thermal behavior of this species, we analyzed the temperature variables CTmin, CTmax, TTR, τheat, and τcool in individuals of three sites from a latitudinal gradient (22°S to 37°S). The amphibians were acclimated to 10°C and 20°C and fed ad libitum. The results indicate that the species has a high thermal tolerance range, with a mean of 38.14±1.34°C, a critical thermal maxima of 34.6-41.4°C, and a critical thermal minima of 2.6-0.8°C, classifying the species as eurythermic. Furthermore, there were significant differences in CTmáx and TTR only in the northern site. The differences in thermal time constants between sites are due to the effects of size and body mass. For example, those from the central site had larger size and greater thermal inertia; therefore, they warmed and cooled in a slower manner. The wide thermal limits determined in R. spinulosa confirm that it is a thermo-generalist species, a characteristic that allows the species to survive in adverse microclimatic conditions. The level of plasticity in critical temperatures seems ecologically relevant and supports the acclimatization of thermal limits as an important factor for ectothermic animals to adapt to climate change. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    DEFF Research Database (Denmark)

    Hermansson, Henrik Alf Jonas; Cross, James

    2015-01-01

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

  17. 76 FR 70479 - Draft Environmental Assessment and Safe Harbor Agreement for the Houston Toad Within Nine Texas...

    Science.gov (United States)

    2011-11-14

    .... Box 1306, Albuquerque, New Mexico 87103 (505) 248-6651). SUPPLEMENTARY INFORMATION: Under a Safe Harbor Agreement, participating property owners voluntarily undertake management activities to enhance...) a detailed account of conservation activities to be undertaken on the portion of the property to be...

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

    DEFF Research Database (Denmark)

    Pedersen, Pil Birkefeldt Møller; Wang, Tobias; Brøndum, Emil Toft

    site of regulation of resistance and therefore holds the capacity to control blood flow and pressure. This vascular control allows amphibians to regulate their shunt, i.e. partially bypassing either the pulmonary or systemic circuit. Shunting in amphibians has been studied due to their multiple...

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

    Directory of Open Access Journals (Sweden)

    Pablo García-Díaz

    2011-02-01

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

  20. Distribution of Boreal Toad Populations in Relation to Estimated UV-B Dose in Glacier National Park, Montana, USA

    Science.gov (United States)

    This work provides information on amphibian distributions as well as the range of UV-B exposure in mountain habitats, and will be of use to scientists interested in tracking changes in amphibian distributions and abundance, and spatial and temporal patterns of UV-B exposure

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

    DEFF Research Database (Denmark)

    Hillyard, Stanley D; Baula, Victor; Tuttle, Wendy

    2007-01-01

    low, V(b) transiently hyperpolarized to values near the equilibrium potential for K(+) and corresponded with the reduced neural response. These results support the hypothesis that chemosensory function of the skin is analogous to that of mammalian taste cells but utilizes paracellular ion transport...

  2. A Mathematical Model of Solute Coupled Water Transport in Toad Intestine Incorporating Recirculation of the Actively Transported Solute

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Sørensen, Jakob Balslev; Sørensen, Jens Nørkær

    2000-01-01

    of the recirculation flux. Robust solutions are obtained with realistic concentrations and pressures of lis, and with the following features. Rate of fluid absorption is governed by the solute permeability of mucosal membrane. Maximum fluid flow is governed by density of pumps on lis-membranes. Energetic efficiency...

  3. Cytopathic effect and plaque formation by arboviruses in a continuous cell line (XTC-2) from the toad Xenopus laevis.

    Science.gov (United States)

    Leake, C J; Varma, M G; Pudney, M

    1977-05-01

    Forty-six arboviruses were tested for c.p.e. and/or plaque formation in an amphibian cell line. C.p.e. was observed with a high proportion of the viruses tested. Comparative plaque assay, in the XTC-2 cells at 28 degrees C and Vero cells at 37 degrees C, suggests that these systems are comparable in sensitivity and susceptibility to infection. Practical uses of this cell line are discussed.

  4. Comparative pathology and ecological implications of two myxosporean parasites in native Australian frogs and the invasive cane toad.

    Directory of Open Access Journals (Sweden)

    Ashlie Hartigan

    Full Text Available Myxosporean parasites Cystodiscus axonis and C. australis are pathogens of native and exotic Australian frog species. The pathology and ecological outcomes of infection with these parasites were investigated in this study. Gliosis was correlated to Cystodiscus axonis plasmodia in the brains of (9/60 tadpoles and (3/9 adult endangered Green and golden bell frogs using ordinal regression. Severe host reactions to C. axonis (haemorrhage, necrosis, and vasulitis were observed in the brains of threatened Southern bell frogs (8/8, critically endangered Booroolong frogs (15/44 and Yellow spotted bell frogs (3/3. Severe brain lesions were associated with behavioural changes, neurological dysfunction, and spontaneous death. Both C. axonis and C. australis develop in the bile ducts of tadpoles, the plasmodia were significantly associated with biliary hyperplasia, inflammation and the loss of hepatocytes in (34/72 Green and golden bell frog tadpoles using ordinal regression. These lesions were so severe that in some cases 70% of the total liver was diseased. Normal liver function in tadpoles is necessary for metamorphosis, metabolism, and immune function. We postulate that this extensive liver damage would have significant host health impacts. Severe hepatic myxosporidiosis was more prevalent in tadpoles examined in autumn and winter (overwintered, suggestive of delayed metamorphosis in infected tadpoles, which would have serious flow-on effects in small populations. We compared the sensitivity of histopathology and species-specific PCR in the detection of C. australis and C. axonis. PCR was determined to be the most sensitive method (detection limit 1 myxospore equivalent of ribosomal DNA. Histology, however, had the advantage of assessing the impact of the parasite on the host. It was concluded that these parasites have the potential for significant ecological impacts, because of their high prevalence of infection and their ability to cause disease in some frogs.

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

    DEFF Research Database (Denmark)

    Nielsen, Robert; Larsen, Erik Hviid

    2007-01-01

    (V) decreased to 0.50+/-0.15 nL cm(-2) x s(-1), which is significantly different from zero. Isoproterenol decreased the osmotic concentration of the transported fluid, C(osm) approximately 2 x I(SC)(Eqv)/J(V), from 351+/-72 to 227+/-28 mOsm (Ringer's solution: 252.8 mOsm). J(V) depicted a saturating function.......2+/-0.3 to 2.4+/-0.4 mS x cm(-2) and slower increases in equivalent short circuit current, I(SC)(Eqv) = -G(T) x V(T), from 12.7+/-3.2 to 33.1+/-6.8 microA cm(-2), and J(V) from 0.72+/-0.17 to 3.01+/-0.49 nL cm(-2) s(-1). Amiloride in the outside solution abolished I(SC)(Eqv) (-1.6+/-0.1 microA cm(-2)) while J......(V) with a [Na+] of the transported fluid of 130+/-24 mM ([Na+]Ringer's solution = 117.4 mM). Addition of bumetanide to the inside solution reduced J(V). Water was transported uphill and J(V) reversed at an excess outside osmotic concentration, deltaC(S,rev) = 28.9+/-3.9 mOsm, amiloride decreased delta...

  6. Avoidance responses to scents of snakes that pose different risks of predation by adult natterjack toads, Bufo calamita

    National Research Council Canada - National Science Library

    Gonzalo, Adega; López, Pilar; Martín, José

    2008-01-01

    ... ( Bufo calamita Laurenti, 1768) was influenced by the presence in the refuge of chemical cues from conspecifics or from two different snake predators ( Natrix maura (L., 1758) and Natrix natrix (L., 1758...

  7. Conservation genetics of the yellow-bellied toad (Bombina variegata) and the common lizard (Zootoca vivipara) in the Italian Alps

    OpenAIRE

    Cornetti, Luca

    2014-01-01

    Global change is heavily affecting Alpine ecosystems in term of both climate warming and anthropization and its effects have been already demonstrated for many different taxa. However, understanding the genetic consequences on wild species caused by environmental modifications is complicated. In this thesis, I analyzed the genetic variation pattern in two vertebrate species whose distribution and persistence across the Italian Alps could be, or already have been, affected by changing climatic...

  8. Morphology, Molecular Genetics, and Bioacoustics Support Two New Sympatric Xenophrys Toads (Amphibia: Anura: Megophryidae) in Southeast China

    Science.gov (United States)

    Wang, Yingyong; Zhao, Jian; Yang, Jianhuan; Zhou, Zhixin; Chen, Guoling; Liu, Yang

    2014-01-01

    Given their recent worldwide declines and extinctions, characterization of species-level diversity is of critical importance for large-scale biodiversity assessments and conservation of amphibians. This task is made difficult by the existence of cryptic species complexes, species groups comprising closely related and morphologically analogous species. The combination of morphology, genetic, and bioacoustic analyses permits robust and accurate species identification. Using these methods, we discovered two undescribed Xenophrys species, namely Xenophrys lini sp. nov. and Xenophrys cheni sp. nov. from the middle range of Luoxiao Mountains, southeast China. These two new species can be reliably distinguished from other known congeners by morphological and morphometric differences, distinctness in male advertisement calls, and substantial genetic distances (>3.6%) based on the mitochondrial 16s and 12s rRNA genes. The two new species, together with X. jinggangensis, are sympatric in the middle range of Luoxiao Mountains but may be isolated altitudinally and ecologically. Our study provides a first step to help resolve previously unrecognized cryptic biodiversity and provides insights into the understanding of Xenophrys diversification in the mountain complexes of southeast China. PMID:24714161

  9. Apoptosis, proliferation and presence of estradiol receptors in the testes and Bidder's organ of the toad Rhinella arenarum (Amphibia, Anura).

    Science.gov (United States)

    Scaia, María Florencia; Czuchlej, Silvia Cristina; Cervino, Nadia; Ceballos, Nora Raquel

    2016-04-01

    The dynamic equilibrium between spermatogonial proliferation and testicular apoptosis determines the progression of spermatogenesis in amphibians. Estrogens and their receptors play a central role in regulating spermatogenesis in vertebrates, and in some species of anurans, estradiol (E2 ) is involved in the regulation of spermatogonial proliferation and apoptosis of germ cells. Bidder's organ (BO) is a structure characteristic of Bufonidae that has historically been compared to an undeveloped ovary. In adult Rhinella arenarum males, BO is one of the main sources of plasma E2 . The aim of this study was 1) to describe the seasonal variations in testicular apoptosis, spermatogonial proliferation, and cellular proliferation in BO; and 2) to analyze the presence and localization of estrogen receptor β (ERβ) in the testes and BO of R. arenarum. Testicular fragments and BOs from animals collected during the year were labeled with 5-bromo-2'-deoxyuridine (BrdU) and BrdU incorporation was determined using immunohistochemistry. Apoptosis in testicular sections was detected using the TUNEL method, and ERβ localization was assessed using immunohistochemistry in testes and BOs. The results indicate that spermatogonial proliferation is highest during the reproductive season and that cysts of spermatocytes and spermatids undergo apoptosis during the postreproductive season. Furthermore, the proliferation of follicular cells is highest during the reproductive and postreproductive seasons. ERβ was primarily detected by immunolocalization in Sertoli cells, follicular cells, and oocytes. Taken together, these results suggest that cysts that do not form spermatozoa are removed from testes by apoptosis and that estrogens regulate both spermatogenesis and oogenesis in adult males of R. arenarum. © 2015 Wiley Periodicals, Inc.

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

    NARCIS (Netherlands)

    Heus, F.A.H.; Otvos, R.A.; Aspers, R.L.E.G.; van Elk, R.; Halff, J.I.; Ehlers, A.W.; Duterte, S.; Lewis, R.J.; Wijmenga, S; Smit, A.B.; Niessen, W.M.A.; Kool, J.

    2014-01-01

    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

  11. Global gene expression analysis provides insight into local adaptation to geothermal streams in tadpoles of the Andean toad Rhinella spinulosa.

    Science.gov (United States)

    Pastenes, Luis; Valdivieso, Camilo; Di Genova, Alex; Travisany, Dante; Hart, Andrew; Montecino, Martín; Orellana, Ariel; Gonzalez, Mauricio; Gutiérrez, Rodrigo A; Allende, Miguel L; Maass, Alejandro; Méndez, Marco A

    2017-05-16

    The anuran Rhinella spinulosa is distributed along the Andes Range at altitudes that undergo wide daily and seasonal variation in temperature. One of the populations inhabits geothermal streams, a stable environment that influences life history traits such as the timing of metamorphosis. To investigate whether this population has undergone local adaptation to this unique habitat, we carried out transcriptome analyses in animals from two localities in two developmental stages (prometamorphic and metamorphic) and exposed them to two temperatures (20 and 25 °C). RNA-Seq, de novo assembly and annotation defined a transcriptome revealing 194,469 high quality SNPs, with 1,507 genes under positive selection. Comparisons among the experimental conditions yielded 1,593 differentially expressed genes. A bioinformatics search for candidates revealed a total of 70 genes that are highly likely to be implicated in the adaptive response of the population living in a stable environment, compared to those living in an environment with variable temperatures. Most importantly, the population inhabiting the geothermal environment showed decreased transcriptional plasticity and reduced genetic variation compared to its counterpart from the non-stable environment. This analysis will help to advance the understanding of the molecular mechanisms that account for the local adaptation to geothermal streams in anurans.

  12. 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...

  13. Environmental DNA as a Tool for Inventory and Monitoring of Aquatic Vertebrates

    Science.gov (United States)

    2017-07-01

    Lithobates [Rana] tarahumarae)3 Western narrow-mouthed toad (Gastrophryne olivacea )4 Woodhouse’s toad (Anaxyrus [Bufo] woodhousii) 1Collected by Meryl...Gastrophryne olivacea )4 Woodhouse’s toad (Anaxyrus [Bufo] woodhousii) 1Collected by Meryl Mims, 2Collected by Lauren Chan, 3Collected by Mike...Lithobates [Rana] tarahumarae)4 Western narrow-mouthed toad (Gastrophryne olivacea )5 Woodhouse’s toad (Anaxyrus [Bufo] woodhousii) 1Collected by Meryl

  14. Mechanisms of ion transport in the mesonephric collecting duct system of Bufo bufo as revealed by microelectrode recordings in isolated perfused tubules

    DEFF Research Database (Denmark)

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

    2002-01-01

    amphibian, Ba2+, Bufo bufo, collecting duct, collecting tubule, K+ conductance, K+ secretion, kidney, mesonephros, ouabain, toad......amphibian, Ba2+, Bufo bufo, collecting duct, collecting tubule, K+ conductance, K+ secretion, kidney, mesonephros, ouabain, toad...

  15. Role of Mitochondria-rich Cells for Passive Chloride Transport, discussion of Ussing's Contribution to Our Understanding of Shunt Pathways in Epithelia

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Kristensen, Poul; Nedergaard, Signe Nielsen

    2001-01-01

    Toad skin, Mitochondria-rich cells, Chloride channels, Epithelial shunt pathways, Leaky epithelia, Recirculation theory of isotonic transport......Toad skin, Mitochondria-rich cells, Chloride channels, Epithelial shunt pathways, Leaky epithelia, Recirculation theory of isotonic transport...

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

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, W.A.; Mendonca, M.T. [Department of Zoology and Wildlife, Auburn University, Auburn, AL 36849 (United States); Congdon, J.D. [Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802 (United States)

    1999-02-01

    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 metabolicclearance 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.)

  17. Drug: D06750 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available cine in Japan [BR:br08304] Crude Drugs Drugs for external use Drugs for external use D06750 Toad venom Crude drugs [BR:br08305] Animals Amphibians D06750 Toad venom PubChem: 47208401 ...

  18. A new Ansonia from the Isthmus of Kra, Thailand (Amphibia, Anura, Bufonidae).

    Science.gov (United States)

    Matsui, Masafumi; Khonsue, Wichase; Nabhitabhata, Jarujin

    2005-07-01

    A new species of torrent-dwelling bufonid frog of the genus Ansonia is described from the Isthmus of Kra, Thailand. Ansonia kraensis is morphologically similar to Malaysian A. malayana, but differs from it in ventral coloration and larval morphology. Occurrence of A. kraensis in this region suggests a heterogeneous nature of the anuran fauna between northern and southern regions of the Malay Peninsula.

  19. Morphological re-evaluation of the parotoid glands of Bufo ictericus (Amphibia, Anura, Bufonidae)

    NARCIS (Netherlands)

    Almeida, de P.G.; Felsemburgh, F.A.; Azevedo, R.A.; Brito-Gitirana, de L.

    2007-01-01

    Multicellular glands in the amphibian integument represent a signifi cant evolutionary advance over those of fi shes. Bufonids have parotoid glands, symmetrically disposed in a post-orbital position. Their secretion may contribute to protection against predators and parasites. This study provides a

  20. A preliminary assessment of the amphibians of the Fouta Djallon, Guinea, West Africa

    NARCIS (Netherlands)

    Hillers, A.; Loua, N.-S.; Rödel, M.-O.

    2008-01-01

    We report on the amphibians of three sites in the Fouta Djallon highlands in central-northern Guinea. During our survey we recorded at least 25 frog species, including two first country records (Kassina fusca and Leptopelis bufonides) and one species new to science (Conraua sp.). Most of the

  1. Military Working Dog Campus Revitalization: Environmental Assessment

    Science.gov (United States)

    2012-12-01

    Blanchard’s cricket frog (Acris crepitans blanchardi), Rio Grande leopard frog (Rana berlandieri), plains narrow mouth toad (Gastrophryne olivacea ), six-lined...Blanchard’s Cricket Frog Acris crepitans blanchardi Rio Grande Leopard Frog Rana berlandieri Plains Narrowmouth Toad Gastrophryne olivacea Red-spotted Toad

  2. blood glucose level in Bufo gutturalis (power)

    African Journals Online (AJOL)

    a larger study dealing with glucose homeostasis in the toad Bufo gutturalis. Seven groups of seven toads each were acclimatized to laboratory conditions for one month. During this period the toads were fed daily on live insects and were housed in a large laboratory terrarium in which the natural habitat was simulated as ...

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

    Science.gov (United States)

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

    2015-11-01

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

  4. A new genus of Toads (Amphibia: Anura: Bufonidae) from the Pacific Slopes of the Andes in Northern Ecuador and Southern Colombia, with the description of two new species

    NARCIS (Netherlands)

    Hoogmoed, M.S.

    1985-01-01

    The genus Andinophryne, characterized by the presence of an omosternum, an externally visible tympanum, elongate parotoids and extensively webbed hands and feet is described from the Pacific versant of the Andes in northwestern Ecuador and southwestern Colombia. Two new species, Andinophryne colomai

  5. The phylogenetic relationships of a new Stream Toad of the genus Ansonia Stoliczka, 1870 (Anura: Bufonidae) from a montane region in Peninsular Malaysia.

    Science.gov (United States)

    Davis, Hayden R; Grismer, L Lee; Klabacka, Randy L; Muin, Mohd Abdul; Quah, Evan S H; Anuar, Shahrul; Wood, Perry L Jr; Sites, Jack W

    2016-04-12

    Twelve species of Ansonia occur on the Thai-Malay peninsula, of which, five from Peninsular Malaysia, form a monophyletic group. One of these, A. jeetsukumarani, is endemic to the Titiwangsa Mountain Range, in which, we discovered a new population of Ansonia that is not A. jeetsukumarani or even its closest relative. Based on morphology, color pattern, and molecular phylogenetic analyses using the mitochondrial genes 12s and 16s rRNA, we have determined that this new species, A. smeagol sp. nov., forms the sister lineage to an upland, monophyletic group composed of A. jeetsukumarani, A. lumut, A. malayana, and A. penangensis. We have noted similar biogeographic patterns in other taxa from the Titiwangsa Mountain Range in a number of upland lineages in Peninsular Malaysia. We hypothesize that the phylogeographic structure of these upland populations is a result of stochastic processes stemming from interaction of climate-driven forest dynamics and life histories.

  6. On The Identity Of Some Toads Of The Genus Bufo From Ecuador, With Additional Remarks On Andinophryne Colomai Hoogmoed, 1985 (Amphibia: Anura: Bufonidae).

    NARCIS (Netherlands)

    Hoogmoed, M.S.

    1989-01-01

    Study of the type specimens of B. caeruleostictus Günther, 1859 and B. chanchanensis Fowler, 1913, and of fresh material showed that B. chanchanensis is a junior subjective synonym of B. caeruleostictus. Probably it is a member of the B. guttatus group. B. caeruleocellatus Fowler, 1913 is a junior

  7. Climate change, thermal niches, extinction risk and maternal-effect rescue of Toad-headed lizards, Phrynocephalus, in thermal extremes of the Arabian Peninsula to the Tibetan Plateau.

    Science.gov (United States)

    Sinervo, Barry; Miles, Donald B; Wu, Yayong; Méndez de la Cruz, Fausto R; Kirchoff, Sebastian; Qi, Yin

    2018-02-13

    Determining the susceptibility of species to changing thermal niches is a major goal for biologists. In this paper we develop an eco-physiological model of extinction risk under climate change premised on behavioral thermoregulation. Our method downscales operative environmental temperatures, which restrict hours of activity of lizards, h r , for present-day climate (1975) and future climate scenarios (2070). We apply our model using occurrence records of 20 Phrynocephalus lizards (or taxa in species complexes) drawn from literature and museum records. Our analysis is phylogenetically informed, because some clades may be more sensitive to rising temperatures. Computed h r limits predict local extirpations among Phrynocephalus lizards at continental scales and delineate upper boundaries of thermal niches as defined by Extreme Value Distributions. Under the 8.5 Representative Concentration Pathway scenario, we predict extirpation of 64% of local populations by 2070 across 20 Phrynocephalus species, and 12 are at high risk of total extinction due to thermal limits being exceeded. In tandem with global strategies of lower CO 2 emissions, we propose regional strategies for establishing new National Parks to protect extinction-prone taxa by preserving high-elevation climate refugia within existing sites of species occurrence. We propose that evolved acclimatization - maternal plasticity - may ameliorate risk, but is poorly studied. Previous studies revealed that adaptive maternal plasticity by thermoregulating gravid females alter progeny thermal preferences by ±1°C. We describe plasticity studies for extinction-prone species that could assess whether they might be buffered from climate warming - a self-rescue. We discuss an epigenetic framework for studying such maternal-effect evolution. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  8. Organ Mass Variation in a Toad Headed Lizard Phrynocephalus vlangalii in Response to Hypoxia and Low Temperature in the Qinghai-Tibet Plateau, China.

    Directory of Open Access Journals (Sweden)

    Jimin Han

    Full Text Available Hypoxia and low temperature at high altitudes are the main environmental pressures for alpine animals, inducing phenotypic plasticity at several levels. To investigate the effect of these variables on the organ mass of Phrynocephalus vlangalii, 138 individuals belonging to four populations living along an altitudinal gradient in the Qinghai-Tibet Plateau (China were dissected to remove heart, lungs, stomach, and intestinal tract. Organ dry mass, individuals' sex, and body mass, as well as mean annual temperature and average air pressure (calculated from a 30-year-data series obtained from the National Climatic Data Center were subjected to two-way analyses of covariance and generalized linear mixed models (GLMMs. Except for the heart, organ mass varied significantly among populations, although only lung and stomach mass increased significantly with increasing altitude. Males' heart and lung mass was higher than that of females, which might be due to their different behavior and reproductive efforts. GLMM analyses indicated that air pressure had a positive effect on heart, lung and intestinal tract mass, whereas temperature had a negative effect on these three organs. In order to explain the effect of hypoxia and low temperature on P. vlangalii's organ mass, further rigorous study on respiration, energy budget and food intake was encouraged.

  9. K+ transport in the mesonephric collecting duct system of the toad Bufo bufo : microelectrode recordings from isolated and perfused tubules

    DEFF Research Database (Denmark)

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

    2002-01-01

    V, respectively (N=11; 11). This conductance could also be inhibited by Ba(2+), which depolarized a V(bl) of -71+/-5 mV by 9+/-3 mV (N=5). The pump inhibitor ouabain (1 mmol l(-1)) depolarized V(bl), but addition of furosemide to bath solution did not affect V(bl). The [K(+)] in urine varied from 1.3 to 22.8 mmol...

  10. Non-target effects of a glyphosate-based herbicide on Common toad larvae (Bufo bufo, Amphibia) and associated algae are altered by temperature

    OpenAIRE

    Baier, Fabian; Gruber, Edith; Hein, Thomas; Bondar-Kunze, Elisabeth; Ivankovi?, Marina; Mentler, Axel; Br?hl, Carsten A.; Spangl, Bernhard; Zaller, Johann G.

    2016-01-01

    Background Glyphosate-based herbicides are the most widely used pesticides in agriculture, horticulture, municipalities and private gardens that can potentially contaminate nearby water bodies inhabited by amphibians and algae. Moreover, the development and diversity of these aquatic organisms could also be affected by human-induced climate change that might lead to more periods with extreme temperatures. However, to what extent non-target effects of these herbicides on amphibians or algae ar...

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

    DEFF Research Database (Denmark)

    Willumsen, N J; Larsen, Erik Hviid

    1986-01-01

    , but was independent of whether the external bath was NaCl-Ringer's, NaCl-Ringer's with amiloride, KCl-Ringer's or choline Cl-Ringer's. To partition the routes of the conductive Cl- ion flow, we measured in the isolated epithelium with double-barrelled microelectrodes apical membrane potential. Va, and intracellular......M in skins from animals adapted to distilled water. Both Va and acCl were found to be positively correlated with Isc (r = 0.66 and r = 0.70, respectively). In eight epithelia from animals adapted to dry milieu/tap water Va and acCl were measured with KCl Ringer's on the outside during activation...... and deactivation of the transepithelial Cl- conductance (GCl) by voltage clamping the transepithelial potential (V) at 40 mV (mucosa positive) and -100 mV. At V = 40 mV; i.e. when GCl was deactivated, Va was -70.1 +/- 5.0 mV (n = 15, eight preparations) and acCl was 40.0 +/- 3.8 mM. The fractional apical membrane...

  12. The 'habitat backbone' as strategy to conserve pioneer species in dynamic port habitats: lessons from the natterjack toad ( Bufo calamita ) in the Port of Antwerp (Belgium)

    NARCIS (Netherlands)

    Snep, R.P.H.; Ottburg, F.G.W.A.

    2008-01-01

    Biodiversity conservation in economic areas like ports has recently become more important in the European Union due to a stricter interpretation of nature protection laws. In this study we develop a planning and design strategy¿the `habitat backbone¿¿ with which to support the long-term survival of

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

    Directory of Open Access Journals (Sweden)

    Petar Boyadzhiev

    2009-07-01

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

  14. A new species of Andean toad (Bufonidae, Osornophryne) discovered using molecular and morphological data, with a taxonomic key for the genus

    Science.gov (United States)

    Páez-Moscoso, Diego J.; Guayasamin, Juan M.; Yánez-Muñoz, Mario

    2011-01-01

    Abstract Combining a molecular phylogeny and morphological data, we discovered a new species of Osornophryne from the Amazonian slope of the Ecuadorian Andes. Morphologically, the new taxon is distinguished from all others species in Osornophryne by having the Toes IV and V longer than Toes I–III, a short and rounded snout with a small rostral papilla, and conical pustules on flanks. The new species previously was confused with Osornophryne guacamayo. A taxonomic key is provided for all known species of Osornophryne. PMID:21852930

  15. Making the Port of Antwerp more natural; ecological infrastructure network for the natterjack toad (Bufo calamita) on the left bank of the Scheldt, Application of the LARCH model to the natterjack toad in the Port of Antwerp on the left bank of the Scheldt as basis for the sustainable conservation of the species

    NARCIS (Netherlands)

    Ottburg, F.G.W.A.; Pouwels, R.; Slim, P.A.

    2007-01-01

    On the grounds of the Antwerp Port Authority, economic activities and nature co-exist in close proximity. To give nature a chance of survival, also into the future, the Port Authority, in collaboration with Natuurpunt, set itself the goal of establishing a network of ecological infrastructure. With

  16. Taxonomic relationships of Ansonia anotis Inger, Tan, and Yambun, 2001 and Pedostibes maculatus (Mocquard, 1890), with a description of a new genus (Amphibia, Bufonidae).

    Science.gov (United States)

    Matsui, Masafumi; Yambun, Paul; Sudin, Ahmad

    2007-11-01

    Examination of types and recently collected specimens revealed that Ansonia anotis Inger, Tan, and Yambun, 2001 and Pedostibes maculatus (Mocquard, 1890), both described from Kinabalu, Sabah, Malaysia, are hardly differentiated morphologically. Analyses of a total of 2,427 bp of the 12S rRNA, tRNA(val), and 16S mitochondrial rRNA genes revealed that the two species are very close genetically. Thus A. anotis is regarded as conspecific and is synonymized with P. maculatus. Genetically, this species proved to form a lineage distinct from other bufonids from Southeast Asia, including species of Ansonia and Pedostibes. Because the species has also some unique morphological traits different from known bufonid genera, we propose to establish a new genus for Nectophryne maculata Mocquard, 1890.

  17. Molecular phylogeny and morphometric analyses reveal deep divergence between Amazonia and Atlantic Forest species of Dendrophryniscus.

    Science.gov (United States)

    Fouquet, Antoine; Recoder, Renato; Teixeira, Mauro; Cassimiro, José; Amaro, Renata Cecília; Camacho, Agustín; Damasceno, Roberta; Carnaval, Ana Carolina; Moritz, Craig; Rodrigues, Miguel Trefaut

    2012-03-01

    Dendrophryniscus is an early diverging clade of bufonids represented by few small-bodied species distributed in Amazonia and the Atlantic Forest. We used mitochondrial (414 bp of 12S, 575 bp of 16S genes) and nuclear DNA (785 bp of RAG-1) to investigate phylogenetic relationships and the timing of diversification within the genus. These molecular data were gathered from 23 specimens from 19 populations, including eight out of the 10 nominal species of the genus as well as Rhinella boulengeri. Analyses also included sequences of representatives of 18 other bufonid genera that were publically available. We also examined morphological characters to analyze differences within Dendrophryniscus. We found deep genetic divergence between an Amazonian and an Atlantic Forest clade, dating back to Eocene. Morphological data corroborate this distinction. We thus propose to assign the Amazonian species to a new genus, Amazonella. The species currently named R. boulengeri, which has been previously assigned to the genus Rhamphophryne, is shown to be closely related to Dendrophryniscus species. Our findings illustrate cryptic trends in bufonid morphological evolution, and point to a deep history of persistence and diversification within the Amazonian and Atlantic rainforests. We discuss our results in light of available paleoecological data and the biogeographic patterns observed in other similarly distributed groups. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. 77 FR 21920 - Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To List the Eastern...

    Science.gov (United States)

    2012-04-12

    ... Colorado and Utah likely create a geographic barrier to migrating toads. Mitochondrial DNA analysis... appear that the Plain is a genetic barrier (Switzer et al. 2009, fig 3). Genetic samples from Clade 3-2... petition erroneously states that the Hell's Canyon portion of the Snake River separates boreal toads along...

  19. Hexamethonium produces both twitch and tetanic depression ...

    African Journals Online (AJOL)

    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 ...

  20. Archaeological Investigations at Sites 45-DO-242 and 45-DO-243, Chief Joseph Dam Project, Washington.

    Science.gov (United States)

    1984-01-01

    242 - NISP=2) Ranidae/ Bufonidae (frogs and toads) 45-D0-242 -- 2 elements. Both frogs and toads Inhabit the project area (Stebbins 1966). Inadequate...Chelydridae Chrysemys pJa Zone 11: 1 shell fragment. Zone 13: 53 shell fragments. Fmllly Ranldae/ Bufonidae Zone 14: 1 skull fragment, I tibia. Failly

  1. Archaeological Investigations at Site 45-DO-285, Chief Joseph Dam Project, Washington.

    Science.gov (United States)

    1984-01-01

    carapace or plastron. ea ’W’ 82 AMPHIBIA (NlSP=167) Ranidae/ Bufonidae (frogs, toads) -- 167 elements. Both frogs and toads inhabit the project area...Ranidae/ Bufonidae Zone 1: 1 skull fragment, 2 lnncoinate fragments, 1 femur fragment. Zone 2: 1 radloulna, 1 tiblofibula Zone 3: 29 humerus fragments, 18

  2. An experimental study on the anti-Ehrlich ascites carcinoma effect of ...

    African Journals Online (AJOL)

    The objective of this paper was to study the anti-Ehrlich ascites carcinoma effect of purified toad venom extract and its mechanism. Mouse model of Ehrlich ascites carcinoma was established with cisplatin as the control to observe the inhibitory effect of purified toad venom extract on malignant peritoneal effusion in mice.

  3. The role of adrenergic receptors in nicotine-induced hyperglycemia ...

    African Journals Online (AJOL)

    The role of adrenergic receptors in nicotine-induced hyperglycaemia has not been well studied in amphibians. Thus, this study investigates the effects of alpha and beta adrenergic receptor blockers in nicotine-induced hyperglycaemia in the common African toad Bufo regularis. Toads fasted for 24 h were anaesthetized with ...

  4. Effects of Petrol Exposure on Glucose, Liver and Muscle glycogen ...

    African Journals Online (AJOL)

    This study investigated the effects of exposure to petrol on blood glucose, liver and muscle glycogen levels in the common African toad Bufo regularis. A total of 126 adult toads of either sex weighing between 70-100g were used for this study. The experiment was divided into three phases. The phase 1 experiment the acute ...

  5. 77 FR 9200 - Los Padres National Forest: California; Environmental Impact Statement for the Removal of the...

    Science.gov (United States)

    2012-02-16

    ... federally listed arroyo toad, California red-legged frog, and steelhead trout. The purpose of this project... as arroyo toad (F-E), California red-legged frog (F-T), southwestern pond turtle (R5-S), two-striped... prevent its further spread on National Forest System land. Tamarisk is a nonnative invasive tree-shrub...

  6. Methods for invasive species control are transferable across invaded areas.

    Science.gov (United States)

    Haramura, Takashi; Crossland, Michael R; Takeuchi, Hirohiko; Shine, Richard

    2017-01-01

    Cane Toads (Rhinella marina) are invasive pests in many parts of the world, including the Japanese island of Ishigaki. Extensive research in Australia has identified promising new methods for control, but also has shown that toads exhibit geographic variation in many traits (suggesting that methods developed in one location may not work in another). Can the approaches developed in Australia play a useful role for controlling this invasive species in Japan? Our experimental trials on Ishigaki Island suggest that these new methods can be successfully applied to Japan. First, Cane Toad embryos exposed to chemical cues of conspecific tadpoles exhibited a reduction in viability (subsequent growth and development). This response appears to be species-specific, with native frog embryos not being affected by exposure to cues from toad tadpoles, and Cane Toad embryos not being affected by exposure to cues from native frog tadpoles. Second, Cane Toad tadpoles were attracted to traps containing water from conspecific eggs, and toxin from adult conspecifics. Third, adult Cane Toads were attracted to acoustic cues of calling males, with sex differences in rates of attraction to specific versions of a synthetic call (males were attracted to choruses whereas females were attracted to low-frequency calls). Our results suggest that the methods developed by Australian researchers are applicable to controlling invasive Cane Toads in Japan.

  7. Download this PDF file

    African Journals Online (AJOL)

    component that causes slow contraction of the guinea pig ileum and rat diaphragm. Five structurally ... Cardiac muscle. Experiments on cardiac muscle were carried out on isolated toad-heart preparations. ... Table 1: Effect of direct perfusion with bumblebee (Bombus morrisoni) venom on heart rate of isolated toad hearts.

  8. Gastrointestinal helminth parasites of Amietophyrnus regularis ...

    African Journals Online (AJOL)

    Gastrointestinal helminth parasites of Amietophyrnus regularis (African Common Toad) in Anyigba were investigated. A total of 120 specimens were examined for helminth parasites, 113(94.17%) toads were infected, while 7(5.8%) were uninfected. Helminth parasites recovered were 1576, comprising of 1 Cestode: ...

  9. Cattle grazing and conservation of a meadow-dependent amphibian species in the Sierra Nevada.

    Directory of Open Access Journals (Sweden)

    Leslie M Roche

    Full Text Available World-wide population declines have sharpened concern for amphibian conservation on working landscapes. Across the Sierra Nevada's national forest lands, where almost half of native amphibian species are considered at risk, permitted livestock grazing is a notably controversial agricultural activity. Cattle (Bos taurus grazing is thought to degrade the quality, and thus reduce occupancy, of meadow breeding habitat for amphibian species of concern such as the endemic Yosemite toad (Anaxyrus [ = Bufo] canorus. However, there is currently little quantitative information correlating cattle grazing intensity, meadow breeding habitat quality, and toad use of meadow habitat. We surveyed biotic and abiotic factors influencing cattle utilization and toad occupancy across 24 Sierra Nevada meadows to establish these correlations and inform conservation planning efforts. We utilized both traditional regression models and Bayesian structural equation modeling to investigate potential drivers of meadow habitat use by cattle and Yosemite toads. Cattle use was negatively related to meadow wetness, while toad occupancy was positively related. In mid and late season (mid July-mid September grazing periods, cattle selected for higher forage quality diets associated with vegetation in relatively drier meadows, whereas toads were more prevalent in wetter meadows. Because cattle and toads largely occupied divergent zones along the moisture gradient, the potential for indirect or direct negative effects is likely minimized via a partitioning of the meadow habitat. During the early season, when habitat use overlap was highest, overall low grazing levels resulted in no detectable impacts on toad occupancy. Bayesian structural equation analyses supported the hypothesis that meadow hydrology influenced toad meadow occupancy, while cattle grazing intensity did not. These findings suggest cattle production and amphibian conservation can be compatible goals within this

  10. Cattle grazing and conservation of a meadow-dependent amphibian species in the Sierra Nevada.

    Science.gov (United States)

    Roche, Leslie M; Latimer, Andrew M; Eastburn, Danny J; Tate, Kenneth W

    2012-01-01

    World-wide population declines have sharpened concern for amphibian conservation on working landscapes. Across the Sierra Nevada's national forest lands, where almost half of native amphibian species are considered at risk, permitted livestock grazing is a notably controversial agricultural activity. Cattle (Bos taurus) grazing is thought to degrade the quality, and thus reduce occupancy, of meadow breeding habitat for amphibian species of concern such as the endemic Yosemite toad (Anaxyrus [ = Bufo] canorus). However, there is currently little quantitative information correlating cattle grazing intensity, meadow breeding habitat quality, and toad use of meadow habitat. We surveyed biotic and abiotic factors influencing cattle utilization and toad occupancy across 24 Sierra Nevada meadows to establish these correlations and inform conservation planning efforts. We utilized both traditional regression models and Bayesian structural equation modeling to investigate potential drivers of meadow habitat use by cattle and Yosemite toads. Cattle use was negatively related to meadow wetness, while toad occupancy was positively related. In mid and late season (mid July-mid September) grazing periods, cattle selected for higher forage quality diets associated with vegetation in relatively drier meadows, whereas toads were more prevalent in wetter meadows. Because cattle and toads largely occupied divergent zones along the moisture gradient, the potential for indirect or direct negative effects is likely minimized via a partitioning of the meadow habitat. During the early season, when habitat use overlap was highest, overall low grazing levels resulted in no detectable impacts on toad occupancy. Bayesian structural equation analyses supported the hypothesis that meadow hydrology influenced toad meadow occupancy, while cattle grazing intensity did not. These findings suggest cattle production and amphibian conservation can be compatible goals within this working landscape.

  11. Demonstration of thymus-independent immune system in Xenopus laevis. Response to polyvinylpyrrolidone.

    Science.gov (United States)

    Tochinai, S

    1976-01-01

    Larvae of Xenopus laevis were thymectomized at stage 45 (4 days old), and raised beyond metamorphosis. Thymectomized toads, when injected with polyvinylpyrrolidone (PVP), produced the same titres of antibodies as non-thymectomized animals, providing strong evidence that the thymus-independent immune response is present in this anuran. Antibodies were of exclusively high molecular weight, heat-stable, and 2-mercaptoethanol sensitive. After immunization, lymphoid accumulations were evident in the splenic white pulp of both thymectomized and non-thymectomized toads, but in the red pulp the accumulations were prominent only in non-thymectomized toads. Images Figure 3 PMID:1027717

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

    Science.gov (United States)

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

    2014-01-01

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

  13. Rahvusvahelisel muuseumipäeval 18. V avati Tartu Kunstimuuseumis Raekoja plats 18... / Reeli Kõiv

    Index Scriptorium Estoniae

    Kõiv, Reeli

    2005-01-01

    Näituse kuraator ülevaatenäitusest "Tartu kunsti lood", mis esitab Tartu kunsti arenguloo rohkem kui pooleteise sajandi lõikes. Näitusega kaasnevad muuseumitunnid ja töötoad igas vanuses lastele ja noortele

  14. Filmifestival õpetas ise filme looma / Aarne Mäe

    Index Scriptorium Estoniae

    Mäe, Aarne, 1967-

    1999-01-01

    30. sept. - 3. okt. Rakvere Exclusiveì ööklubis toimunud Põhjamaade ja Baltikumi noorte videofilmide filmifestivali "Visions of Light" raames tegutsesid ka töötoad : Eesti nukufilmi töötuba ja "Video netis"

  15. Guide to Inventory and Monitoring of Streamside Salamanders in Shenandoah National Park, Virginia Supplement No. 2 to Amphibian Decline in the Mid-Atlantic Region; Monitoring and Management of a Sensitive Resource. Final Report to the Legacy Resource Management Program. U.S. Department of Defense.

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Amphibians (frogs, toads, salamanders) have become recognized widely as sensitive indicators of environmental change. They have permeable skin, gills, and eggs that...

  16. EKÜLi arengukoostööprojekt korteriühistute loomise ja tegevuse toetamiseks Valgevenes ja Ukrainas = Проект развития сотрудничества Союза Квартирных Товариществ Эстонии для созда

    Index Scriptorium Estoniae

    2013-01-01

    Eesti Korteriühistute Liidu elluviidud projektist "Korteriühistuliikumise kogemus ja korteriühistu mudel - töötoad Valgevenes ja Ukrainas". Valgevene ja Ukraina elamufondi haldamisest, elamu- ja kommunaalmajandusest

  17. Moriyama tubamajad väikesele pinnale

    Index Scriptorium Estoniae

    2008-01-01

    Jaapani arhitektid on lahendanud probleemi, kuidas võimalikult väikesele pinnale mahutada tavalise pere elamine. Kõik toad on eraldiseisvate aiamajakestena paigutatud väiksele krundile kõrvuti, üksteise peale ja vahele

  18. Ahju tuleb kütta kuivade puude ja kõva tulega / Arvo Uustalu

    Index Scriptorium Estoniae

    Uustalu, Arvo, 1964-

    2006-01-01

    Vt. ka Linnaleht : Pärnu ; Linnaleht : Tartu 10. veebr., lk. B3. Tartus tegutseva ahjupotivabriku omanik ja ahjumeister Annes Andersson annab nõu, kuidas ja millega kütta, et toad oleksid mõnusalt soojad

  19. Dong Quai

    Science.gov (United States)

    ... of bleeding and bruising. These herbs include angelica, clove, garlic, ginger, ginkgo, panax ginseng, and others. ... dong quai, Cistanches deserticola, Zanthoxyl species, Torlidis seed, clove flower, Asiasari root, cinnamon bark, and toad venom (SS ...

  20. Bufo alvarius: a potent hallucinogen of animal origin.

    Science.gov (United States)

    Weil, A T; Davis, W

    1994-01-01

    Anthropologists have long speculated that ancient peoples of Mesoameria used a toad, Bufo marinus, as a ritual intoxicant. This hypothesis rests on many iconographic and mythological representations of toads and on a number of speculative ethnographic reports. The authors reject B. marinus as a candidate for such use because of the toxicity of its venom. A more likely candidate is the Sonoran desert toad, Bufo alvarius, which secretes large amounts of the potent known hallucinogen, 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT). The authors demonstrate that the venom of B. alvarius, although known to be toxic when consumed orally, may be safely smoked and is powerfully psychoactive by that route of administration. These experiments are the first documentation of an hallucinogenic agent from the animal kingdom, and they provide clear evidence of a psychoactive toad that could have been employed by Precolumbian peoples of the New World.

  1. Valge fungi uus tulemine / Kersti Pikk

    Index Scriptorium Estoniae

    Pikk, Kersti

    2007-01-01

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

  2. Development of a Standardized Approach for Assessing Potential Risks to Amphibians Exposed to Sediment and Hydric Soils

    Science.gov (United States)

    2004-05-01

    of their life history. Amphibia Gymnophiona - caecilians Caudata - salamanders Anura - frogs and toads Batrachia Simplified Amphibian Phylogenic...Amphibian Trophic Status The class Amphibia is extremely diverse, with an enormous array of species-specific Amphibian Ecological Risk Assessment

  3. amphibian_biomarker_data

    Data.gov (United States)

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

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

    DEFF Research Database (Denmark)

    Ji, Hua; Cleary, C. S.; Dailey, J. M.

    2012-01-01

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

  5. Comparison of methods for measuring travel time at Florida freeways and arterials : [summary].

    Science.gov (United States)

    2014-07-01

    In this project, University of Florida researchers : collected field data along several highways to : evaluate travel time measurements from several : sources: STEWARD, BlueTOAD, INRIX, and HERE. : STEWARD (Statewide Transportation Engineering : Ware...

  6. Preliminary study of the diet of the European mink (Mustela lubreola ) in the southwest of France

    OpenAIRE

    Libois, Roland

    2001-01-01

    The diet has been studied in 3 zones where two species, polecat and European mink, cohabiting. Feces were collected at the animals resting-place with radio transmitters. The diet of mink is electic : mammals (Ondatra, Arvicola sapidus, rats…), birds (duck, rallids…), frogs and toads and fish. The polecat eats mammals (rabbits, hares and small mammals), some birds and reptiles, plenty toads. The trophic similarity is fairly low. In fact, for two weasels , individual and seasonal varia...

  7. 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

    Directory of Open Access Journals (Sweden)

    Germano Woehl Jr.

    2002-06-01

    Full Text Available 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 prevalence 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.

  8. Mitogenome assembly from genomic multiplex libraries: comparison of strategies and novel mitogenomes for five species of frogs.

    Science.gov (United States)

    Machado, D J; Lyra, M L; Grant, T

    2016-05-01

    Next-generation sequencing continues to revolutionize biodiversity studies by generating unprecedented amounts of DNA sequence data for comparative genomic analysis. However, these data are produced as millions or billions of short reads of variable quality that cannot be directly applied in comparative analyses, creating a demand for methods to facilitate assembly. We optimized an in silico strategy to efficiently reconstruct high-quality mitochondrial genomes directly from genomic reads. We tested this strategy using sequences from five species of frogs: Hylodes meridionalis (Hylodidae), Hyloxalus yasuni (Dendrobatidae), Pristimantis fenestratus (Craugastoridae), and Melanophryniscus simplex and Rhinella sp. (Bufonidae). These are the first mitogenomes published for these species, the genera Hylodes, Hyloxalus, Pristimantis, Melanophryniscus and Rhinella, and the families Craugastoridae and Hylodidae. Sequences were generated using only half of one lane of a standard Illumina HiqSeq 2000 flow cell, resulting in fewer than eight million reads. We analysed the reads of Hylodes meridionalis using three different assembly strategies: (1) reference-based (using bowtie2); (2) de novo (using abyss, soapdenovo2 and velvet); and (3) baiting and iterative mapping (using mira and mitobim). Mitogenomes were assembled exclusively with strategy 3, which we employed to assemble the remaining mitogenomes. Annotations were performed with mitos and confirmed by comparison with published amphibian mitochondria. In most cases, we recovered all 13 coding genes, 22 tRNAs, and two ribosomal subunit genes, with minor gene rearrangements. Our results show that few raw reads can be sufficient to generate high-quality scaffolds, making any Illumina machine run using genomic multiplex libraries a potential source of data for organelle assemblies as by-catch. © 2015 John Wiley & Sons Ltd.

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

    Science.gov (United States)

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

    2008-06-01

    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.

  10. Disease in a dynamic landscape: host behavior and wildfire reduce amphibian chytrid infection

    Science.gov (United States)

    Hossack, Blake R.; Lowe, Winsor H.; Ware, Joy L.; Corn, Paul Stephen

    2013-01-01

    Disturbances are often expected to magnify effects of disease, but these effects may depend on the ecology, behavior, and life history of both hosts and pathogens. In many ecosystems, wildfire is the dominant natural disturbance and thus could directly or indirectly affect dynamics of many diseases. To determine how probability of infection by the aquatic fungus Batrachochytrium dendrobatidis (Bd) varies relative to habitat use by individuals, wildfire, and host characteristics, we sampled 404 boreal toads (Anaxyrus boreas boreas) across Glacier National Park, Montana (USA). Bd causes chytridiomycosis, an emerging infectious disease linked with widespread amphibian declines, including the boreal toad. Probability of infection was similar for females and the combined group of males and juveniles. However, only 9% of terrestrial toads were infected compared to >30% of aquatic toads, and toads captured in recently burned areas were half as likely to be infected as toads in unburned areas. We suspect these large differences in infection reflect habitat choices by individuals that affect pathogen exposure and persistence, especially in burned forests where warm, arid conditions could limit Bd growth. Our results show that natural disturbances such as wildfire and the resulting diverse habitats can influence infection across large landscapes, potentially maintaining local refuges and host behaviors that facilitate evolution of disease resistance.

  11. Evidence of disease-related amphibian decline in Colorado

    Science.gov (United States)

    Muths, Erin; Corn, Paul Stephen; Pessier, Allan P.; Green, D. Earl

    2003-01-01

    The recent discovery of a pathogenic fungus (Batrachochytrium dendrobatidis) associated with declines of frogs in the American and Australian tropics, suggests that at least the proximate cause, may be known for many previously unexplained amphibian declines. We have monitored boreal toads in Colorado since 1991 at four sites using capturea??recapture of adults and counts of egg masses to examine the dynamics of this metapopulation. Numbers of male toads declined in 1996 and 1999 with annual survival rate averaging 78% from 1991 to 1994, 45% in 1995 and 3% between 1998 and 1999. Numbers of egg masses also declined. An etiological diagnosis of chytridiomycosis consistent with infections by the genus Batrachochytrium was made in six wild adult toads. Characteristic histomorphological features (i.e. intracellular location, shape of thalli, presence of discharge tubes and rhizoids) of chytrid organisms, and host tissue response (acanthosis and hyperkeratosis) were observed in individual toads. These characteristics were indistinguishable from previously reported mortality events associated with chytrid fungus. We also observed epizootiological features consistent with mortality events associated with chytrid fungus: an increase in the ratio of female:male toads captured, an apparent spread of mortalities within the metapopulation and mortalities restricted to post metamorphic animals. Eleven years of population data suggest that this metapopulation of toads is in danger of extinction, pathological and epizootiological evidence indicates that B. dendrobatidis has played a proximate role in this process

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

    Directory of Open Access Journals (Sweden)

    Tonglei Yu

    2012-02-01

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

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

    Directory of Open Access Journals (Sweden)

    CAROLINA E GALLARDO

    2011-09-01

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

  14. Microbiome Variation Across Amphibian Skin Regions: Implications for Chytridiomycosis Mitigation Efforts.

    Science.gov (United States)

    Bataille, Arnaud; Lee-Cruz, Larisa; Tripathi, Binu; Kim, Hyoki; Waldman, Bruce

    2016-01-01

    Cutaneous bacteria may play an important role in the resistance of amphibians to the pathogenic fungus Batrachochytrium dendrobatidis (Bd). Microbial communities resident on hosts' skin show topographical diversity mapping to skin features, as demonstrated by studies of the human microbiome. We examined skin microbiomes of wild and captive fire-bellied toads (Bombina orientalis) for differences across their body surface. We found that bacterial communities differed between ventral and dorsal skin. Wild toads showed slightly higher bacterial richness and diversity in the dorsal compared to the ventral region. On the other hand, captive toads hosted a higher richness and diversity of bacteria on their ventral than their dorsal skin. Microbial community composition and relative abundance of major bacterial taxonomic groups also differed between ventral and dorsal skin in all populations. Furthermore, microbiome diversity patterns varied as a function of their Bd infection status in wild toads. Bacterial richness and diversity was greater, and microbial community structure more complex, in wild than captive toads. The results suggest that bacterial community structure is influenced by microhabitats associated with skin regions. These local communities may be differentially modified when interacting with environmental bacteria and Bd. A better understanding of microbiome variation across skin regions will be needed to assess how the skin microbiota affects the abilities of amphibian hosts to resist Bd infection, especially in captive breeding programs.

  15. New fossil record of Bufonidae (Amphibia, Anura in the Late Pleistocene-early Holocene of northeastern Brazil and its paleoenvironmental significance

    Directory of Open Access Journals (Sweden)

    Hermínio Ismael de Araújo-Júnior

    2016-02-01

    Full Text Available We report the first occurrence of anurans in the Quaternary fossil record of Rio Grande do Norte State. The specimen UERN PV-50 was assigned to the bufonid Rhinella jimi. This finding extends the geographic distribution of this species in the northeastern Brazil during the Late Pleistocene-early Holocene. In paleoenvironmental terms, the occurrence of R. jimi in Riacho Verde paleontological site suggests an arid climate with marked seasonality in that area during the Late Pleistocene-early Holocene and that the paleobiodiversity in that region was higher than the observed in the fossil record. Furthermore, the tanks seem to have been areas of aggregating anurans during raining periods. Finally, based on sedimentological and biostratinomic data, we interpret that Riacho Verde paleontological site preserved a peripheral assemblage.

  16. Rhabdias paraensis sp. nov.: a parasite of the lungs of Rhinella marina (Amphibia: Bufonidae) from Brazilian Amazonia.

    Science.gov (United States)

    Santos, Jeannie Nascimento dos; Melo, Francisco Tiago de Vasconcelos; Nascimento, Luciana de Cássia Silva do; Nascimento, Daisy Esther Batista do; Giese, Elane Guerreiro; Furtado, Adriano Penha

    2011-06-01

    The nematode parasites of Rhinella marina include species of the genus Rhabdias (Rhabdiasidae: Rhabditoidea). The present study describes Rhabdias paraensis sp. nov., which parasitizes the lungs of R. marina in Brazilian Amazonia. Of the more than 70 known species of this genus, 18 are parasites of bufonids, of which, eight are Neotropical. The new species described here is similar to Rhabdias alabialis in the absence of lips is different by the presence of conspicuous cephalic papillae. We describe details of the four rows of pores, which are distributed equally along the whole of the length of the body and connected with hypodermal cells, using histology and scanning electron microscopy. Other histological aspects of the internal structure of this nematode are also described.

  17. Pesticides Are Involved With Population Declines of Amphibians in the California Sierra Nevadas

    Directory of Open Access Journals (Sweden)

    Donald W. Sparling

    2001-01-01

    Full Text Available Several species of frogs and toads are in serious decline in the Sierra Nevada Mountains of California. These species include the threatened red-legged frog (Rana aurora, foothill yellow-legged frog (R. boylii, mountain yellow-legged frog (R. muscosa, Cascades frog (Rana cascadae, western toad (Bufo boreas and Yosemite toad (B. canorus. For many of these species current distributions are down to 10% of historical ranges [1,2]. Several factors including introduced predators [3,4,5], habitat loss [2], and ultraviolet radiation [6] have been suggested as causes of these declines. Another probable cause is air-borne pesticides from the Central Valley of California. The Central Valley, especially the San Joaquin Valley, is a major agricultural region where millions of pounds of active ingredient pesticides are applied each year (http://www.cdpr.ca.gov/dprdatabase.htm. Prevailing westerly winds from the Pacific Coast transport these pesticides into the Sierras [7,8].

  18. Better late than never

    DEFF Research Database (Denmark)

    Womack, Molly C; Christensen-Dalsgaard, Jakob; Hoke, Kim L

    2016-01-01

    Most vertebrates have evolved a tympanic middle ear that enables effective hearing of airborne sound on land. Although inner ears develop during the tadpole stages of toads, tympanic middle ear structures are not complete until months after metamorphosis, potentially limiting the sensitivity...... of post-metamorphic juveniles to sounds in their environment. We tested the hearing of five species of toads to determine how delayed ear development impairs airborne auditory sensitivity. We performed auditory brainstem recordings to test the hearing of the toads and used micro-CT and histology to relate...... the development of ear structures to hearing ability. We find a large (14-27 dB) increase in hearing sensitivity from 900 to 2500 Hz over the course of ear development. Thickening of the tympanic annulus cartilage and full ossification of the middle ear bone are associated with increased hearing ability...

  19. Identifying species conservation strategies to reduce disease-associated declines

    Science.gov (United States)

    Gerber, Brian D.; Converse, Sarah; Muths, Erin L.; Crockett, Harry J.; Mosher, Brittany A.; Bailey, Larissa L.

    2017-01-01

    Emerging infectious diseases (EIDs) are a salient threat to many animal taxa, causing local and global extinctions, altering communities and ecosystem function. The EID chytridiomycosis is a prominent driver of amphibian declines, which is caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd). To guide conservation policy, we developed a predictive decision-analytic model that combines empirical knowledge of host-pathogen metapopulation dynamics with expert judgment regarding effects of management actions, to select from potential conservation strategies. We apply our approach to a boreal toad (Anaxyrus boreas boreas) and Bd system, identifying optimal strategies that balance tradeoffs in maximizing toad population persistence and landscape-level distribution, while considering costs. The most robust strategy is expected to reduce the decline of toad breeding sites from 53% to 21% over 50 years. Our findings are incorporated into management policy to guide conservation planning. Our online modeling application provides a template for managers of other systems challenged by EIDs.

  20. Detection of nerve growth factor (NGF) in venoms from diverse source: isolation and characterization of NGF from the venom of honey bee (Apis melifera).

    Science.gov (United States)

    Lipps, B V

    2000-02-01

    Pearce (1973) reported the absence of NGF in the venoms of bees, scorpions, spiders, and toads. Contrary to the negative findings in the past, results of this research prove the presence of NGF in bee and scorpion venoms. Venoms from various species of snake, bee, scorpion, and toad were screened by two methods: immunological test ELISA using antibodies versus mouse NGF and venom NGF and the biological test of neurite outgrowth, the characteristic of NGF on PC cells. The presence of NGF was detected in snake, bee, and scorpion venoms, but not in toad venom by these tests. NGF was isolated from bee venom by HPLC fractionation using ion exchange chromatography. The molecular weight of bee NGF was found to be 14.0 kDa resolving into a single band by PAGE. The biological activity of bee NGF on PC12 cells was found to be 1/10 of the venom NGF.